Pirfenidone Induces G1 Arrest in Human Tenon's Fibroblasts In Vitro Involving AKT and MAPK Signaling Pathways.

PubMed

Guo, Xiujuan; Yang, Yangfan; Liu, Liling; Liu, Xiaoan; Xu, Jiangang; Wu, Kaili; Yu, Minbin

2017-06-01

To investigate the underlying mechanism by which pirfenidone blocks the transition from the G1 to S phase in primary human Tenon's fibroblasts. Primary human Tenon's fibroblasts were characterized by immunocytofluorescence staining with vimentin, fibroblast surface protein, and cytokeratin. After treating Tenon's fibroblasts with pirfenidone under proliferation conditions (10% fetal bovine serum), cell proliferation was measured using a WST-1 assay. Progression through the cell cycle was analyzed by flow cytometry. The expression of CDK2, CDK6, cyclinD1, cyclinD3, and cyclinE and the phosphorylation of AKT, ERK1/2/MAPK, JNK/MAPK, and p38 MAPK were estimated using western blot analysis. Under proliferative conditions, pirfenidone inhibited Tenon's fibroblasts proliferation and arrested the cell cycle at the G1 phase; decreased the phosphorylation of AKT, GSK3β, ERK1/2/MAPK, and JNK/MAPK; increased the phosphorylation of p38 MAPK; and inhibited CDK2, CDK6, cyclin D1, cyclin D3, and cyclin E in a dose-dependent manner. Inhibitors of AKT (LY294002), ERK1/2 (U0126), and JNK (SP600125) arrested the G1/S transition, similar to the effect of pirfenidone. The p38 inhibitor (SB202190) decreased the G1-blocking effect of pirfenidone. The expression of CDK2, CDK6, cyclin D1, and cyclin D3 were inhibited by LY294002, U0126, and SP600125. SB202190 attenuated the pirfenidone-induced reduction of CDK2, CDK6, cyclin D1, cyclin D3, and cyclin E. Pirfenidone inhibited HTFs proliferation and induced G1 arrest by downregulating CDKs and cyclins involving the AKT/GSK3β and MAPK signaling pathways.

Cyclin D2 induces proliferation of cardiac myocytes and represses hypertrophy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Busk, Peter K.; Hinrichsen, Rebecca; Bartkova, Jirina

2005-03-10

The myocytes of the adult mammalian heart are considered unable to divide. Instead, mitogens induce cardiomyocyte hypertrophy. We have investigated the effect of adenoviral overexpression of cyclin D2 on myocyte proliferation and morphology. Cardiomyocytes in culture were identified by established markers. Cyclin D2 induced DNA synthesis and proliferation of cardiomyocytes and impaired hypertrophy induced by angiotensin II and serum. At the molecular level, cyclin D2 activated CDK4/6 and lead to pRB phosphorylation and downregulation of the cell cycle inhibitors p21{sup Waf1/Cip1} and p27{sup Kip1}. Expression of the CDK4/6 inhibitor p16 inhibited proliferation and cyclin D2 overexpressing myocytes became hypertrophic undermore » such conditions. Inhibition of hypertrophy by cyclin D2 correlated with downregulation of p27{sup Kip1}. These data show that hypertrophy and proliferation are highly related processes and suggest that cardiomyocyte hypertrophy is due to low amounts of cell cycle activators unable to overcome the block imposed by cell cycle inhibitors. Cell cycle entry upon hypertrophy may be converted to cell division by increased expression of activators such as cyclin D2.« less

The expression status of TRX, AR, and cyclin D1 correlates with clinicopathological characteristics and ER status in breast cancer.

PubMed

Huang, Weisun; Nie, Weiwei; Zhang, Wenwen; Wang, Yanru; Zhu, Aiyu; Guan, Xiaoxiang

2016-01-01

The ER signaling pathway plays a critical role in breast cancer. ER signaling pathway-related proteins, such as TRX, AR, and cyclin D1, may have an important function in breast cancer. However, the ways that they influence breast cancer development and progression are still unclear. A total of 101 Chinese female patients diagnosed with invasive ductal breast adenocarcinoma were retrospectively enrolled in the study. The expression levels of TRX, AR, and cyclin D1 were detected by immunohistochemistry and analyzed via correlation with clinicopathological characteristics and the expression status of ER, PR, and HER2. The expression status of TRX, AR, and cyclin D1 was not associated with the patient's age, menopausal status, tumor size, or histological differentiation (P>0.05), but was positively correlated with ER and PR (P<0.001, respectively). Most (66/76, 86.8) TRX-positive patients were also HER2-positive (P=0.003). Of AR- or cyclin D1-positive patients, most had relatively earlier I-II tumor stage (P=0.005 and P=0.047, respectively) and no metastatic lymph node involvement (P=0.008 and P=0.005, respectively). TRX was found to be positively correlated with ER and PR expression, whereas it was negatively correlated with HER2 expression. In addition, we found that the positive expression of AR and cyclin D1 was correlated with lower TNM stage and fewer metastatic lymph nodes, and it was more common in ER-positive breast cancer than in the basal-like subtype. This may indicate that AR and cyclin D1 are good predictive and prognostic factors and closely interact with ER signaling pathway. Further studies will be necessary to investigate the response and clinical outcomes of treatment targeting TRX, AR, and cyclin D1.

Cyclin D1 Repression of Peroxisome Proliferator-Activated Receptor γ Expression and Transactivation

PubMed Central

Wang, Chenguang; Pattabiraman, Nagarajan; Zhou, Jian Nian; Fu, Maofu; Sakamaki, Toshiyuki; Albanese, Chris; Li, Zhiping; Wu, Kongming; Hulit, James; Neumeister, Peter; Novikoff, Phyllis M.; Brownlee, Michael; Scherer, Philipp E.; Jones, Joan G.; Whitney, Kathleen D.; Donehower, Lawrence A.; Harris, Emily L.; Rohan, Thomas; Johns, David C.; Pestell, Richard G.

2003-01-01

The cyclin D1 gene is overexpressed in human breast cancers and is required for oncogene-induced tumorigenesis. Peroxisome proliferator-activated receptor γ (PPARγ) is a nuclear receptor selectively activated by ligands of the thiazolidinedione class. PPARγ induces hepatic steatosis, and liganded PPARγ promotes adipocyte differentiation. Herein, cyclin D1 inhibited ligand-induced PPARγ function, transactivation, expression, and promoter activity. PPARγ transactivation induced by the ligand BRL49653 was inhibited by cyclin D1 through a pRB- and cdk-independent mechanism, requiring a region predicted to form an helix-loop-helix (HLH) structure. The cyclin D1 HLH region was also required for repression of the PPARγ ligand-binding domain linked to a heterologous DNA binding domain. Adipocyte differentiation by PPARγ-specific ligands (BRL49653, troglitazone) was enhanced in cyclin D1−/− fibroblasts and reversed by retroviral expression of cyclin D1. Homozygous deletion of the cyclin D1 gene, enhanced expression by PPARγ ligands of PPARγ and PPARγ-responsive genes, and cyclin D1−/− mice exhibit hepatic steatosis. Finally, reduction of cyclin D1 abundance in vivo using ponasterone-inducible cyclin D1 antisense transgenic mice, increased expression of PPARγ in vivo. The inhibition of PPARγ function by cyclin D1 is a new mechanism of signal transduction cross talk between PPARγ ligands and mitogenic signals that induce cyclin D1. PMID:12917338

Protocatechualdehyde possesses anti-cancer activity through downregulating cyclin D1 and HDAC2 in human colorectal cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeong, Jin Boo; Lee, Seong-Ho, E-mail: slee2000@umd.edu

Highlights: Black-Right-Pointing-Pointer Protocatechualdehyde (PCA) suppressed cell proliferation and induced apoptosis in human colorectal cancer cells. Black-Right-Pointing-Pointer PCA enhanced transcriptional downregulation of cyclin D1 gene. Black-Right-Pointing-Pointer PCA suppressed HDAC2 expression and activity. Black-Right-Pointing-Pointer These findings suggest that anti-cancer activity of PCA may be mediated by reducing HDAC2-derived cyclin D1 expression. -- Abstract: Protocatechualdehyde (PCA) is a naturally occurring polyphenol found in barley, green cavendish bananas, and grapevine leaves. Although a few studies reported growth-inhibitory activity of PCA in breast and leukemia cancer cells, the underlying mechanisms are still poorly understood. Thus, we performed in vitro study to investigate if treatment ofmore » PCA affects cell proliferation and apoptosis in human colorectal cancer cells and define potential mechanisms by which PCA mediates growth arrest and apoptosis of cancer cells. Exposure of PCA to human colorectal cancer cells (HCT116 and SW480 cells) suppressed cell growth and induced apoptosis in dose-dependent manner. PCA decreased cyclin D1 expression in protein and mRNA level and suppressed luciferase activity of cyclin D1 promoter, indicating transcriptional downregulation of cyclin D1 gene by PCA. We also observed that PCA treatment attenuated enzyme activity of histone deacetylase (HDAC) and reduced expression of HDAC2, but not HDAC1. These findings suggest that cell growth inhibition and apoptosis by PCA may be a result of HDAC2-mediated cyclin D1 suppression.« less

Lysine-specific demethylase 2A expression is associated with cell growth and cyclin D1 expression in colorectal adenocarcinoma.

PubMed

Cao, Lin-Lin; Du, Changzheng; Liu, Hangqi; Pei, Lin; Qin, Li; Jia, Mei; Wang, Hui

2018-04-01

Lysine-specific demethylase 2A (KDM2A), a specific H3K36me1/2 demethylase, has been reported to be closely associated with several types of cancer. In this study, we aimed to investigate the expression and function of KDM2A in colorectal adenocarcinoma. A total of 215 colorectal adenocarcinoma specimens were collected, and then subjected to immunohistochemistry assay to evaluate the expression levels of KDM2A, cyclin D1 and other proteins in colorectal adenocarcinoma tissues. Real-time polymerase chain reaction, Western blot, and other molecular biology methods were used to explore the role of KDM2A in colorectal adenocarcinoma cells. In this study, we report that the expression level of KDM2A is high in colorectal adenocarcinoma tissues, and this high expression promotes the proliferation and colony formation of colorectal adenocarcinoma cells, as demonstrated by KDM2A knockdown experiments. In addition, the expression of KDM2A is closely associated with cyclin D1 expression in colorectal adenocarcinoma tissues and cell lines. Our study reveals a novel role for high-expressed KDM2A in colorectal adenocarcinoma cell growth, and that the expression of KDM2A is associated with that of cyclin D1 in colorectal adenocarcinoma.

Analysis of signal transducer and activator of transcription 3 (Stat 3) pathway in multiple myeloma: Stat 3 activation and cyclin D1 dysregulation are mutually exclusive events.

PubMed

Quintanilla-Martinez, Leticia; Kremer, Marcus; Specht, Katja; Calzada-Wack, Julia; Nathrath, Michaela; Schaich, Robert; Höfler, Heinz; Fend, Falko

2003-05-01

The signal transducer and activator of transcription molecules (Stats) play key roles in cytokine-induced signal transduction. Recently, it was proposed that constitutively activated Stat 3 (Stat 3 phosphorylated) contributes to the pathogenesis of multiple myeloma (MM) by preventing apoptosis and inducing proliferation. The study aim was to investigate Stat 3 activation in a series of multiple myeloma (MM) cases and its effect on downstream targets such as the anti-apoptotic proteins Bcl-xL, Mcl-1, and Bcl-2, and the cell-cycle protein cyclin D1. Forty-eight cases of MM were analyzed. Immunohistochemistry was performed on paraffin sections using antibodies against cyclin D1, Bcl-2, Bcl-xL, Mcl-1, p21, Stat 3, and Stat 3 phosphorylated (P). Their specificity was corroborated by Western blot analysis using eight human MM cell lines as control. The proliferation rate was assessed with the antibody MiB1. In addition, the mRNA levels of cyclin D1 and Stat 3 were determined by quantitative real-time reverse transcriptase-polymerase chain reaction of paraffin-embedded microdissected tissue. Three different groups determined by the expression of Stat 3P and cyclin D1 (protein and mRNA) were identified: group 1, Stat 3-activated (23 cases, 48%). All cases revealed nuclear expression of Stat 3P. No elevation of Stat 3 mRNA was identified in any of the cases. Three cases in this group showed intermediate to low cyclin D1 protein and mRNA expression. Group 2 included 15 (31%) cases with cyclin D1 staining and lack of Stat 3P. All cases showed intermediate to high levels of cyclin D1 mRNA expression. Group 3 included 10 (21%) cases with no expression of either cyclin D1 or Stat 3P. High levels of anti-apoptotic proteins Bcl-xL and Mcl-1 were identified in 89% and 100% of all cases, respectively. In contrast to Bcl-xL and Mcl-1, the expression of Bcl-2 showed an inverse correlation with proliferation rate (P: 0.0003). No significant differences were found between the three groups in terms of proliferation rate or expression of anti-apoptotic proteins. However, cyclin D1+ cases were always well differentiated and were more likely to show a lymphoplasmocytoid differentiation (chi-square = 9.55). Overall, constitutive activation of Stat 3 was found in almost half (48%) of the investigated MM cases. However, this does not seem to have a major impact on the expression of anti-apoptotic proteins and proliferation. We showed that cyclin D1 overexpression and Stat 3 activation are, mutually exclusive events in MM (P = 0.0066). The universal expression of Mcl-1, independent of activated Stat 3, suggests that its expression is constitutive and that it might play an important role in the pathogenesis of MM.

BRCA1-IRIS regulates cyclin D1 expression in breast cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakuci, Enkeleda; Mahner, Sven; DiRenzo, James

2006-10-01

The regulator of cell cycle progression, cyclin D1, is up-regulated in breast cancer cells; its expression is, in part, dependent on ER{alpha} signaling. However, many ER{alpha}-negative tumors and tumor cell lines (e.g., SKBR3) also show over-expression of cyclin D1. This suggests that, in addition to ER{alpha} signaling, cyclin D1 expression is under the control of other signaling pathways; these pathways may even be over-expressed in the ER{alpha}-negative cells. We previously noticed that both ER{alpha}-positive and -negative cell lines over-express BRCA1-IRIS mRNA and protein. Furthermore, the level of over-expression of BRCA1-IRIS in ER{alpha}-negative cell lines even exceeded its over-expression level inmore » ER{alpha}-positive cell lines. In this study, we show that: (1) BRCA1-IRIS forms complex with two of the nuclear receptor co-activators, namely, SRC1 and SRC3 (AIB1) in an ER{alpha}-independent manner. (2) BRCA1-IRIS alone, or in connection with co-activators, is recruited to the cyclin D1 promoter through its binding to c-Jun/AP1 complex; this binding activates the cyclin D1 expression. (3) Over-expression of BRCA1-IRIS in breast cells over-activates JNK/c-Jun; this leads to the induction of cyclin D1 expression and cellular proliferation. (4) BRCA1-IRIS activation of JNK/c-Jun/AP1 appears to account for this, because in cells that were depleted from BRCA1-IRIS, JNK remained inactive. However, depletion of SRC1 or SRC3 instead reduced c-Jun expression. Our data suggest that this novel signaling pathway links BRCA1-IRIS to cellular proliferation through c-Jun/AP1 nuclear pathway; finally, this culminates in the increased expression of the cyclin D1 gene.« less

Anticancer activity of calyx of Diospyros kaki Thunb. through downregulation of cyclin D1 via inducing proteasomal degradation and transcriptional inhibition in human colorectal cancer cells.

PubMed

Park, Su Bin; Park, Gwang Hun; Song, Hun Min; Son, Ho-Jun; Um, Yurry; Kim, Hyun-Seok; Jeong, Jin Boo

2017-09-05

Although it has been reported to contain high polyphenols, the pharmacological studies of the calyx of Diospyros kaki Thunb (DKC) have not been elucidated in detail. In this study, we elucidated anti-cancer activity and potential molecular mechanism of DKC against human colorectal cancer cells. Anti-cell proliferative effect of 70% ethanol extracts from the calyx of Diospyros kaki (DKC-E70) was evaluated by MTT assay. The effect of DKC-E70 on the expression of cyclin D1 in the protein and mRNA level was evaluated by Western blot and RT-PCR, respectively. DKC-E70 suppressed the proliferation of human colorectal cancer cell lines such as HCT116, SW480, LoVo and HT-29. Although DKC-E70 decreased cyclin D1 expression in protein and mRNA level, decreased level of cyclin D1 protein by DKC-E70 occurred at the earlier time than that of cyclin D1 mRNA, which indicates that DKC-E70-mediated downregulation of cyclin D1 protein may be a consequence of the induction of degradation and transcriptional inhibition of cyclin D1. In cyclin D1 degradation, we found that cyclin D1 downregulation by DKC-E70 was attenuated in presence of MG132. In addition, DKC-E70 phosphorylated threonine-286 (T286) of cyclin D1 and T286A abolished cyclin D1 downregulation by DKC-E70. We also observed that DKC-E70-mediated T286 phosphorylation and subsequent cyclin D1 degradation was blocked in presence of the inhibitors of ERK1/2, p38 or GSK3β. In cyclin D1 transcriptional inhibition, DKC-E70 inhibited the expression of β-catenin and TCF4, and β-catenin/TCF-dependent luciferase activity. Our results suggest that DKC-E70 may downregulate cyclin D1 as one of the potential anti-cancer targets through cyclin D1 degradation by T286 phosphorylation dependent on ERK1/2, p38 or GSK3β, and cyclin D1 transcriptional inhibition through Wnt signaling. From these findings, DKC-E70 has potential to be a candidate for the development of chemoprevention or therapeutic agents for human colorectal cancer.

Bioinformatics prediction and experimental validation of microRNA-20a targeting Cyclin D1 in hepatocellular carcinoma.

PubMed

Karimkhanloo, Hamzeh; Mohammadi-Yeganeh, Samira; Ahsani, Zeinab; Paryan, Mahdi

2017-04-01

Hepatocellular carcinoma is the major form of primary liver cancer, which is the second and sixth leading cause of cancer-related death in men and women, respectively. Extensive research indicates that Wnt/β-catenin signaling pathway, which plays a pivotal role in growth, development, and differentiation of hepatocellular carcinoma, is one of the major signaling pathways that is dysregulated in hepatocellular carcinoma. Cyclin D1 is a proto-oncogene and is one of the major regulators of Wnt signaling pathway, and its overexpression has been detected in various types of cancers including hepatocellular carcinoma. Using several validated bioinformatic databases, we predicted that the microRNAs are capable of targeting 3'-untranslated region of Cyclin D1 messenger RNA. According to the results, miR-20a was selected as the highest ranking microRNA targeting Cyclin D1 messenger RNA. Luciferase assay was recruited to confirm bioinformatic prediction results. Cyclin D1 expression was first assessed by quantitative real-time polymerase chain reaction in HepG2 cell line. Afterward, HepG2 cells were transduced by lentiviruses containing miR-20a. Then, the expression of miR-20a and Cyclin D1 was evaluated. The results of luciferase assay demonstrated targeting of 3'-untranslated region of Cyclin D1 messenger RNA by miR-20a. Furthermore, 238-fold decline in Cyclin D1 expression was observed after lentiviral induction of miR-20a in HepG2 cells. The results highlighted a considerable effect of miRNA-20a induction on the down-regulation of Cyclin D1 gene. Our results suggest that miR-20a can be used as a novel candidate for therapeutic purposes and a biomarker for hepatocellular carcinoma diagnosis.

PKCeta enhances cell cycle progression, the expression of G1 cyclins and p21 in MCF-7 cells.

PubMed

Fima, E; Shtutman, M; Libros, P; Missel, A; Shahaf, G; Kahana, G; Livneh, E

2001-10-11

Protein kinase C encodes a family of enzymes implicated in cellular differentiation, growth control and tumor promotion. However, not much is known with respect to the molecular mechanisms that link protein kinase C to cell cycle control. Here we report that the expression of PKCeta in MCF-7 cells, under the control of a tetracycline-responsive inducible promoter, enhanced cell growth and affected the cell cycle at several points. The induced expression of another PKC isoform, PKCdelta, in MCF-7 cells had opposite effects and inhibited their growth. PKCeta expression activated cellular pathways in these cells that resulted in the increased expression of the G1 phase cyclins, cyclin D and cyclin E. Expression of the cyclin-dependent kinase inhibitor p21(WAF1) was also specifically elevated in PKCeta expressing cells, but its overall effects were not inhibitory. Although, the protein levels of the cyclin-dependent kinase inhibitor p27(KIP1) were not altered by the induced expression of PKCeta, the cyclin E associated Cdk2 kinase activity was in correlation with the p27(KIP1) bound to the cyclin E complex and not by p21(WAF1) binding. PKCeta expression enhanced the removal of p27(KIP1) from this complex, and its re-association with the cyclin D/Cdk4 complex. Reduced binding of p27(KIP1) to the cyclin D/Cdk4 complex at early time points of the cell cycle also enhanced the activity of this complex, while at later time points the decrease in bound p21(WAF1) correlated with its increased activity in PKCeta-expressing cells. Thus, PKCeta induces altered expression of several cell cycle functions, which may contribute to its ability to affect cell growth.

Cyclin D1 is significantly associated with stage of tumor and predicts poor survival in endometrial carcinoma patients.

PubMed

Khabaz, Mohamad Nidal; Abdelrahman, Amer Shafie; Butt, Nadeem Shafique; Al-Maghrabi, Basim; Al-Maghrabi, Jaudah

2017-10-01

Cyclin D1 overexpression has been described to have oncogenic role and association with diagnosis, prognosis and survival in various tumors. This study will describe the immunohistochemical phenotype of cyclin D1, and investigate the correlation between these patterns of expression and clinicopathological parameters of endometrial carcinomas, to conclude the clinical relevance of cyclin D1 expression in the evolution of endometrial neoplasms. This study employed 101 endometrial tissue samples which include 71 endometrial carcinomas and thirty normal and benign endometrium cases. All these tissue samples were used in the assembly of tissue microarrays which have been utilized afterward in immunohistochemistry staining to detect cyclin D1 expression. Forty (56.3%) cases of endometrial carcinomas showed brown nuclear expression of cyclin D1 including 36 (61%) cases of endometrioid carcinomas, and 3 (33.3%) cases of serous carcinomas. Twenty three (76.6%) cases of control group demonstrated nuclear expression. High score cyclin D1 immunohistochemical staining has been significantly linked with patient age (P=0.0001). Large proportion of high score cyclin D1 immunohistochemical staining was observed in females who are <40years of age while high proportions of negative staining were observed in older age groups. Histologic type of tissue was also significantly related to cyclin D1 immunohistochemical staining (P-value=0.0001), high staining is more common in normal proliferative and secretory endometrium while serous carcinoma is more prevalent with negative staining. Stage of tumor was significantly associated with cyclin D1 immunohistochemical staining (P-value=0.029), proportion of stage III and IV are higher in negative cyclin D1 immunostaining. Significantly higher proportion of high score cyclin D1 immunostaining is observed in controls while higher proportion of negative cyclin D1 immunostaining is observed among carcinoma cases (P-value=0.0001). No significant associations between cyclin D1 immunohistochemical staining and grade, recurrence and alive status were observed. Significant different survival distributions were observed (P-value=0.011) and poor survival behavior was correlated with negative cyclin D1 immunohistochemical staining. In conclusion, greater frequency of cyclin D1 expression was revealed in normal endometrial tissues in comparison with carcinomas. The distribution pattern of cyclin D1 immunoexpression suggests poor prognoses in endometrial carcinoma patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Oncogenic collaboration of the cyclin D1 (PRAD1, bcl-1) gene with a mutated p53 and an activated ras oncogene in neoplastic transformation.

PubMed

Uchimaru, K; Endo, K; Fujinuma, H; Zukerberg, L; Arnold, A; Motokura, T

1996-05-01

Cyclin D1 is one of the key regulators in G1 progression in the cell cycle and is also a candidate oncogene (termed PRAD1 or bcl-1) in several types of human tumors. We report a collaboration of the cyclin D1 gene with ras and a mutated form of p53 (p53-mt) in neoplastic transformation. Transfection of cyclin D1 alone or in combination with ras or with p53-mt was not sufficient for focus formation of rat embryonic fibroblasts. However, focus formation induced by co-transfection of ras and p53-mt was enhanced in the presence of the cyclin D1-expression plasmid. Co-transfection of ras- and p53-mt-transformants with the cyclin D1-expression plasmid resulted in reduced serum dependency in vitro. Furthermore, the transformants expressing exogenous cyclin D1 grew faster than those without the cyclin D1 plasmid when injected into nude mice. These observations strengthen the significance of cyclin D1 overexpression through gene rearrangement or gene amplification observed in human tumors as a step in multistep oncogenesis; deregulated expression of cyclin D1 may reduce the requirement for growth factors and may stimulate in vivo growth.

Inhibition of cyclin D1 enhances sensitivity to radiotherapy and reverses epithelial to mesenchymal transition for esophageal cancer cells.

PubMed

Su, Huafang; Jin, Xiance; Shen, Lanxiao; Fang, Ya; Fei, Zhenghua; Zhang, Xuebang; Xie, Congying; Chen, Xiaolei

2016-04-01

Acquired radioresistance during radiotherapy has significantly affected the treatment efficacy in esophageal cancer. Many of radioresistant cancer cells demonstrated epithelial-mesenchymal transition (EMT).We found in previous study that a radioresistant cell line (KYSE-150R) possessed EMT characteristic with cyclin D1 overexpression. Cyclin D1 has been demonstrated to affect the radiation sensitivity in cancer cells. To elucidate the molecular functions of cyclin D1 on EMT phenotypes and esophageal cancer radiosensitivity, we treated the radioresistant esophageal cancer cells (KYSE-150R) and parental cells (KYSE-150) with cyclin D1 small interfering RNA (siRNA). The cell proliferation rate of KYSE-150R and the radiation survival fraction were significantly decreased in cyclin D1 siRNA treatment group. Knocking down cyclin D1 resulted in G0/G1 arrest in KYSE-150R cells. The average number of irradiation-induced γ-H2AX foci increased in the cells treated with cyclin D1 siRNA, indicating impaired DNA double-strand break (DSB) repair in KYSE-150R cells. Cyclin D1 also reversed EMT phenotypes with significantly increased expression of E-cadherin in KYSE-150R cells. However, cyclin D1 siRNA have no radiosensitizing effects on KYSE-150 cells, with no obvious change in EMT marker expression .Our work showed that EMT phenotypes can be reduced and the radiosensitivity of esophageal cancer cells can be enhanced by inhibiting cyclin D1.

Cyclin D regulation of a sexually dimorphic asymmetric cell division

PubMed Central

Tilmann, Christopher; Kimble, Judith

2006-01-01

SUMMARY The C. elegans somatic gonadal precursor cell (SGP) divides asymmetrically to establish gonad-specific coordinates in both sexes. In addition, the SGP division is sexually dimorphic and initiates sex-specific programs of gonadogenesis. Wnt/MAPK signaling determines the gonadal axes, and the FKH-6 transcription factor specifies the male mode of SGP division. In this paper, we demonstrate that C. elegans cyclin D controls POP-1/TCF asymmetry in the SGP daughters as well as fkh-6 and rnr expression in the SGPs. Although cyclin D mutants have delayed SGP divisions, the cyclin D defects are not mimicked by other methods of retarding the SGP division. We find that EFL-1/E2F has an antagonistic effect on fkh-6 expression and gonadogenesis, which is relieved by cyclin D activity. We propose that cyclin D and other canonical regulators of the G1/S transition coordinate key regulators of axis formation and sex determination with cell cycle progression to achieve the sexually dimorphic SGP asymmetric division. PMID:16198291

[The expression of Cyclin D1 modulated by somatotropin on human pancreas cancer cell lines Bxpc-3].

PubMed

Li, Fei; Liu, Da-chuan; Sun, Jia-bang

2004-04-07

To observe the growth effect of somatostapin on human pancreas cancer lines Bxpc-3. The Bxpc-3 pancreas cancer cells were treated with Somatotropin. The cells hyperplasia were detected by MTT and were observed apoptosis cells determinated quantitatively by TUNEL, quantify immune fluoresence double marked the proliferation cells and apoptosis cells, the expression of Cyclin D1 detected by immunohistochemical. The growth effect of pancrea cancer cells were limited by 10(-7) M, 10(-8) M, 10(-9) M Somatotropin on 2 day. The limited effect was decreased from 3 day. The cells proliferation were increased by somotostapin on 4day to 5day. The relationship between the expression of Cyclin D1 and apoptosis was negative correlation and the cells hyperplasia was positive correlation in Bxpc-3 cell line. From the cell study we knew the expression of Cyclin D1 reflected the prolefiration of pancreas cancer cells.

[Effect of Jianpi Yangzheng Xiaozheng Recipe on Apoptosis and Autophagy of Subcutaneous Transplanted Tumor in Nude Mice: an Experimental Study on Mechanism].

PubMed

Wu, Jian; Liu, Shen-lin; Zhang, Xing-xing; Chen, Min; Zou, Xi

2015-09-01

To observe the effect of Jianpi Yangzheng Xiaozheng Recipe (JYXR) on the tumor inhibition rate of subcutaneous transplanted tumor gastric cancer cell line MGC-803 in BALB/c nude mice, and to study its molecular mechanism of apoptosis and autophagy. Gastric cancer cell line MGC-803 was subcutaneously inoculated to nude mice for preparing transplanted gastric cancer models. Totally 32 BALB/c nude mice were randomly divided into 4 groups according to random digit table, i.e., the negative control group, the positive control group, the high dose JYXR group, the low dose JYXR group, 8 in each group. Normal saline was administered to mice in the negative control group by gastrogavage. 5-fluorouracil (5-Fu) at 2. 5 mg/kg was administered to mice in the positive control group by gastrogavage. JYXR at 85 and 43 g/kg was administered to mice in the high dose JYXR group and the low dose JYXR group by gastrogavage, once per day for 10 successive days. The effect of JYXR on the tumor inhibition rate of subcutaneous transplanted tumor was observed. Effects of JYXR on gene expression levels of Bax, Bcl-2, Fas, Cyclin D1, Cyclin D2, and Cyclin D3 in transplanted tumor were observed by real-time PCR. Effects of JYXR on protein expression levels of Procaspase-3, Procaspase-8, Procaspase-9, cleaved-PARP, Beclin-1, and LC3B were detected using Western blot. (1) Compared with the negative control group, the tumor weight was obviously reduced in the rest three groups (P <0. 05). The tumor weight was higher in the high dose JYXR group and the low dose JYXR group than in the positive control group (P <0. 05). (2) Results of RT-PCR indicated that, compared with the negative control group, expression levels of Bax were up-regulated, but expression levels of Bcl-2, Cyclin D1, Cyclin D2, and Cyclin D3 were down-regulated in the positive control group and JYXR groups (P <0. 05). The expression level of Fas was up-regulated in the positive control group and the high dose JYXR group (P <0. 05). Compared with the positive control group, expression levels of Fas, and Bax were all down-regulated, but expression levels of Bcl-2, Cyclin D2, and Cyclin D3 were all up-regulated in the high dose JYXR group and the low dose JYXR group (all P <0. 05). The expression level of Cyclin D1 was down-regulated in the high dose JYXR group, but it was up-regulated in the low dose JYXR group ( both P <0. 05). (3) Results of Western blot showed, compared with the negative control group, expression levels of Procaspase-3, Procaspase-8, and Procaspase-9 were down-regulated, but expression levels of cleaved-PARP, Beclin-1, and LC3B II were up-regulated in the high dose JYXR group and the low dose JYXR group (all P <0.05). Compared with the negative control group, expression levels of Procaspase-3, Procaspase-8, Procaspase-9, and LC3B II were down-regulated, but expression levels of cleaved-PARP, Beclin-1, and LC3B I were up-regulated in the positive control group (all P <0. 05). JYXR showed significant inhibition on subcutaneous transplanted tumor gastric cancer cell line MGC-803 in BALB/c nude mice. Its mechanism might be associated with activating apoptosis and autophagy correlated factors.

Transforming Growth Factor β Inhibits Platelet Derived Growth Factor-Induced Vascular Smooth Muscle Cell Proliferation via Akt-Independent, Smad-Mediated Cyclin D1 Downregulation

PubMed Central

Martin-Garrido, Abel; Williams, Holly C.; Lee, Minyoung; Seidel-Rogol, Bonnie; Ci, Xinpei; Dong, Jin-Tang; Lassègue, Bernard; Martín, Alejandra San; Griendling, Kathy K.

2013-01-01

In adult tissue, vascular smooth muscle cells (VSMCs) exist in a differentiated phenotype, which is defined by the expression of contractile proteins and lack of proliferation. After vascular injury, VSMC adopt a synthetic phenotype associated with proliferation, migration and matrix secretion. The transition between phenotypes is a consequence of the extracellular environment, and in particular, is regulated by agonists such as the pro-differentiating cytokine transforming growth factor β (TGFβ) and the pro-proliferative cytokine platelet derived growth factor (PDGF). In this study, we investigated the interplay between TGFβ and PDGF with respect to their ability to regulate VSMC proliferation. Stimulation of human aortic VSMC with TGFβ completely blocked proliferation induced by all isoforms of PDGF, as measured by DNA synthesis and total cell number. Mechanistically, PDGF-induced Cyclin D1 mRNA and protein expression was inhibited by TGFβ. TGFβ had no effect on PDGF activation of its receptor and ERK1/2, but inhibited Akt activation. However, constitutively active Akt did not reverse the inhibitory effect of TGFβ on Cyclin D1 expression even though inhibition of the proteasome blocked the effect of TGFβ. siRNA against Smad4 completely reversed the inhibitory effect of TGFβ on PDGF-induced Cyclin D1 expression and restored proliferation in response to PDGF. Moreover, siRNA against KLF5 prevented Cyclin D1 upregulation by PDGF and overexpression of KLF5 partially reversed TGFβ-induced inhibition of Cyclin D1 expression. Taken together, our results demonstrate that KLF5 is required for PDGF-induced Cyclin D1 expression, which is inhibited by TGFβ via a Smad dependent mechanism, resulting in arrest of VSMCs in the G1 phase of the cell cycle. PMID:24236150

Transforming growth factor β inhibits platelet derived growth factor-induced vascular smooth muscle cell proliferation via Akt-independent, Smad-mediated cyclin D1 downregulation.

PubMed

Martin-Garrido, Abel; Williams, Holly C; Lee, Minyoung; Seidel-Rogol, Bonnie; Ci, Xinpei; Dong, Jin-Tang; Lassègue, Bernard; Martín, Alejandra San; Griendling, Kathy K

2013-01-01

In adult tissue, vascular smooth muscle cells (VSMCs) exist in a differentiated phenotype, which is defined by the expression of contractile proteins and lack of proliferation. After vascular injury, VSMC adopt a synthetic phenotype associated with proliferation, migration and matrix secretion. The transition between phenotypes is a consequence of the extracellular environment, and in particular, is regulated by agonists such as the pro-differentiating cytokine transforming growth factor β (TGFβ) and the pro-proliferative cytokine platelet derived growth factor (PDGF). In this study, we investigated the interplay between TGFβ and PDGF with respect to their ability to regulate VSMC proliferation. Stimulation of human aortic VSMC with TGFβ completely blocked proliferation induced by all isoforms of PDGF, as measured by DNA synthesis and total cell number. Mechanistically, PDGF-induced Cyclin D1 mRNA and protein expression was inhibited by TGFβ. TGFβ had no effect on PDGF activation of its receptor and ERK1/2, but inhibited Akt activation. However, constitutively active Akt did not reverse the inhibitory effect of TGFβ on Cyclin D1 expression even though inhibition of the proteasome blocked the effect of TGFβ. siRNA against Smad4 completely reversed the inhibitory effect of TGFβ on PDGF-induced Cyclin D1 expression and restored proliferation in response to PDGF. Moreover, siRNA against KLF5 prevented Cyclin D1 upregulation by PDGF and overexpression of KLF5 partially reversed TGFβ-induced inhibition of Cyclin D1 expression. Taken together, our results demonstrate that KLF5 is required for PDGF-induced Cyclin D1 expression, which is inhibited by TGFβ via a Smad dependent mechanism, resulting in arrest of VSMCs in the G1 phase of the cell cycle.

Mediator of RNA polymerase II transcription subunit 19 promotes osteosarcoma growth and metastasis and associates with prognosis.

PubMed

Yu, Wenxi; Zhang, Zhichang; Min, Daliu; Yang, Qingcheng; Du, Xuefei; Tang, Lina; Lin, Feng; Sun, Yuanjue; Zhao, Hui; Zheng, Shuier; He, Aina; Li, Hongtao; Yao, Yang; Shen, Zan

2014-04-01

Osteosarcoma (OS) is the most common primary malignant tumour of bone. Nearly 30-40% of OS patients have a poor prognosis despite multimodal treatments. Because the carcinogenesis of OS remains unclear, the identification of new oncogenes that control the tumourigenesis and progression of OS is crucial for developing new therapies. Here, we found that the expression of Mediator of RNA polymerase II transcription subunit 19 (Med19) was increased in OS samples from patients compared to normal bone tissues. Cyclin D1 and cyclin B1 are upregulated in Med19 positive OS tissues. Importantly, among 97 OS patients of Enneking stage IIB or IIIB, Med19 expression was correlated with metastasis (P<0.05) and poor prognosis (P<0.01). Med19 knockdown significantly induced growth inhibition, reduced colony-forming ability and suppressed migration in the OS cell lines Saos-2 and U2OS, along with the downregulated expression of cyclin D1 and cyclin B1. Med19 knockdown also induced apoptosis in Saos-2 cells via induction of caspase-3 and poly ADP-ribose polymerase (PARP). In addition, Med19 knockdown significantly suppressed tumour growth in an OS xenograft nude mouse model via suppression of cyclin D1 and cyclin B1. Simultaneously, Med19 downregulation decreased the expression of Ki67 and proliferating cell nuclear antigen (PCNA) in tumour samples from OS xenograft nude mice. Med19 depletion remarkably reduced tumour metastasis in a model of OS metastatic spreading. Taken together, our data suggest that Med19 acts as an oncogene in OS via a possible cyclin D1/cyclin B1 modulation pathway. Copyright © 2014 Elsevier Ltd. All rights reserved.

BAFF induces spleen CD4{sup +} T cell proliferation by down-regulating phosphorylation of FOXO3A and activates cyclin D2 and D3 expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ji, Fang; Chen, Rongjing; Liu, Baojun

2012-09-07

Highlights: Black-Right-Pointing-Pointer Firstly analyze the mechanism of BAFF and anti-CD3 co-stimulation on purified mouse splenic CD4{sup +} T cells. Black-Right-Pointing-Pointer Carrying out siRNA technology to study FOXO3A protein function. Black-Right-Pointing-Pointer Helpful to understand the T cell especially CD4{sup +} T cell's role in immunological reaction. -- Abstract: The TNF ligand family member 'B cell-activating factor belonging to the TNF family' (BAFF, also called BLyS, TALL-1, zTNF-4, and THANK) is an important survival factor for B and T cells. In this study, we show that BAFF is able to induce CD4{sup +} spleen T cell proliferation when co-stimulated with anti-CD3. Expressionmore » of phosphorylated FOXO3A was notably down-regulated and cyclins D2 and D3 were up-regulated and higher in the CD4{sup +} T cells when treated with BAFF and anti-CD3, as assessed by Western blotting. Furthermore, after FOXO3A was knocked down, expression of cyclin D1 was unchanged, compared with control group levels, but the expression of cyclins D2 and D3 increased, compared with the control group. In conclusion, our results suggest that BAFF induced CD4{sup +} spleen T cell proliferation by down-regulating the phosphorylation of FOXO3A and then activating cyclin D2 and D3 expression, leading to CD4{sup +} T cell proliferation.« less

Cyclin D1b splice variant promotes αvβ3-mediated adhesion and invasive migration of breast cancer cells.

PubMed

Wu, Feng-Hua; Luo, Li-Qiong; Liu, Yi; Zhan, Qiu-Xiao; Luo, Chao; Luo, Jing; Zhang, Gui-Mei; Feng, Zuo-Hua

2014-12-01

Cyclin D1b, a splice variant of the cell cycle regulator cyclin D1, holds oncogenic functions in human cancer. However, the mechanisms underlying cyclin D1b function remain poorly understood. Here we introduced wild-type cyclin D1a or cyclin D1b variant into non-metastatic MCF-7 cells. Our results show that ectopic expression of cyclin D1b promotes invasiveness of the cancer cells in a cyclin D1a independent manner. Specifically, cyclin D1b is found to modulate the expression of αvβ3, which characterizes the metastatic phenotype, and enhance tumor cell invasive potential in cooperating with HoxD3. Notably, cyclin D1b promotes αvβ3-mediated adhesion and invasive migration, which are associated with invasive potential of breast cancer cells. Further exploration indicates that cyclin D1b makes breast cancer cells more sensitive to toll-like receptor 4 ligand released from damaged tumor cells. These findings reveal a role of cyclin D1b as a possible mediator of αvβ3 transcription to promote tumor metastasis. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Cytoplasmic sequestration of cyclin D1 associated with cell cycle withdrawal of neuroblastoma cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sumrejkanchanakij, Piyamas; Department of Anatomy, Faculty of Dentistry, Chulalongkorn University, Bangkok 10330; Eto, Kazuhiro

2006-02-03

The regulation of D-type cyclin-dependent kinase activity is critical for neuronal differentiation and apoptosis. We recently showed that cyclin D1 is sequestered in the cytoplasm and that its nuclear localization induces apoptosis in postmitotic primary neurons. Here, we further investigated the role of the subcellular localization of cyclin D1 in cell cycle withdrawal during the differentiation of N1E-115 neuroblastoma cells. We show that cyclin D1 became predominantly cytoplasmic after differentiation. Targeting cyclin D1 expression to the nucleus induced phosphorylation of Rb and cdk2 kinase activity. Furthermore, cyclin D1 nuclear localization promoted differentiated N1E-115 cells to reenter the cell cycle, amore » process that was inhibited by p16{sup INK4a}, a specific inhibitor of D-type cyclin activity. These results indicate that cytoplasmic sequestration of cyclin D1 plays a role in neuronal cell cycle withdrawal, and suggests that the abrogation of machinery involved in monitoring aberrant nuclear cyclin D1 activity contributes to neuronal tumorigenesis.« less

Cytoplasmic sequestration of cyclin D1 associated with cell cycle withdrawal of neuroblastoma cells.

PubMed

Sumrejkanchanakij, Piyamas; Eto, Kazuhiro; Ikeda, Masa-Aki

2006-02-03

The regulation of D-type cyclin-dependent kinase activity is critical for neuronal differentiation and apoptosis. We recently showed that cyclin D1 is sequestered in the cytoplasm and that its nuclear localization induces apoptosis in postmitotic primary neurons. Here, we further investigated the role of the subcellular localization of cyclin D1 in cell cycle withdrawal during the differentiation of N1E-115 neuroblastoma cells. We show that cyclin D1 became predominantly cytoplasmic after differentiation. Targeting cyclin D1 expression to the nucleus induced phosphorylation of Rb and cdk2 kinase activity. Furthermore, cyclin D1 nuclear localization promoted differentiated N1E-115 cells to reenter the cell cycle, a process that was inhibited by p16(INK4a), a specific inhibitor of D-type cyclin activity. These results indicate that cytoplasmic sequestration of cyclin D1 plays a role in neuronal cell cycle withdrawal, and suggests that the abrogation of machinery involved in monitoring aberrant nuclear cyclin D1 activity contributes to neuronal tumorigenesis.

Overexpression of TRPV3 Correlates with Tumor Progression in Non-Small Cell Lung Cancer.

PubMed

Li, Xiaolei; Zhang, Qianhui; Fan, Kai; Li, Baiyan; Li, Huifeng; Qi, Hanping; Guo, Jing; Cao, Yonggang; Sun, Hongli

2016-03-24

(1) BACKGROUND: Transient receptor potential vanilloid 3 (TRPV3) is a member of the TRP channels family of Ca(2+)-permeant channels. The proteins of some TRP channels are highly expressed in cancer cells. This study aimed to assess the clinical significance and biological functions of TRPV3 in non-small cell lung cancer (NSCLC); (2) METHODS: Immunohistochemistry was used to detect the expression of TRPV3 in NSCLC tissues and adjacent noncancerous lung tissues. Western blot was used to detect the protein expressions of TRPV3, CaMKII, p-CaMKII, CyclinA, CyclinD, CyclinE1, CDK2, CDK4, and P27. Small interfering RNA was used to deplete TRPV3 expression. A laser scanning confocal microscope was used to measure intracellular calcium concentration ([Ca(2+)]i). Flow cytometry was used to analyze cell cycle; (3) RESULTS: TRPV3 was overexpressed in 65 of 96 (67.7%) human lung cancer cases and correlated with differentiation (p = 0.001) and TNM stage (p = 0.004). Importantly, TRPV3 expression was associated with short overall survival. In addition, blocking or knockdown of TRPV3 could inhibit lung cancer cell proliferation. Moreover, TRPV3 inhibition could decrease [Ca(2+)]i of lung cancer cells and arrest cell cycle at the G1/S boundary. Further results revealed that TRPV3 inhibition decreased expressions of p-CaMKII, CyclinA, CyclinD1, CyclinE, and increased P27 level; (4) CONCLUSIONS: Our findings demonstrate that TRPV3 was overexpressed in NSCLC and correlated with lung cancer progression. TRPV3 activation could promote proliferation of lung cancer cells. TRPV3 might serve as a potential companion drug target in NSCLC.

Overexpression of TRPV3 Correlates with Tumor Progression in Non-Small Cell Lung Cancer

PubMed Central

Li, Xiaolei; Zhang, Qianhui; Fan, Kai; Li, Baiyan; Li, Huifeng; Qi, Hanping; Guo, Jing; Cao, Yonggang; Sun, Hongli

2016-01-01

(1) Background: Transient receptor potential vanilloid 3 (TRPV3) is a member of the TRP channels family of Ca2+-permeant channels. The proteins of some TRP channels are highly expressed in cancer cells. This study aimed to assess the clinical significance and biological functions of TRPV3 in non-small cell lung cancer (NSCLC); (2) Methods: Immunohistochemistry was used to detect the expression of TRPV3 in NSCLC tissues and adjacent noncancerous lung tissues. Western blot was used to detect the protein expressions of TRPV3, CaMKII, p-CaMKII, CyclinA, CyclinD, CyclinE1, CDK2, CDK4, and P27. Small interfering RNA was used to deplete TRPV3 expression. A laser scanning confocal microscope was used to measure intracellular calcium concentration ([Ca2+]i). Flow cytometry was used to analyze cell cycle; (3) Results: TRPV3 was overexpressed in 65 of 96 (67.7%) human lung cancer cases and correlated with differentiation (p = 0.001) and TNM stage (p = 0.004). Importantly, TRPV3 expression was associated with short overall survival. In addition, blocking or knockdown of TRPV3 could inhibit lung cancer cell proliferation. Moreover, TRPV3 inhibition could decrease [Ca2+]i of lung cancer cells and arrest cell cycle at the G1/S boundary. Further results revealed that TRPV3 inhibition decreased expressions of p-CaMKII, CyclinA, CyclinD1, CyclinE, and increased P27 level; (4) Conclusions: Our findings demonstrate that TRPV3 was overexpressed in NSCLC and correlated with lung cancer progression. TRPV3 activation could promote proliferation of lung cancer cells. TRPV3 might serve as a potential companion drug target in NSCLC. PMID:27023518

[Circadian rhythm variation of the clock genes Per1 and cell cycle related genes in different stages of carcinogenesis of buccal mucosa in animal model].

PubMed

Tan, Xuemei; Ye, Hua; Yang, Kai; Chen, Dan; Tang, Hong

2015-07-01

To investigate the expression and circadian rhythm variation of biological clock gene Per1 and cell cycle genes p53, CyclinD1, cyclin-dependent kinases (CDK1), CyclinB1 in different stages of carcinogenesis in buccal mucosa and its relationship with the development of buccal mucosa carcinoma. Ninety golden hamsters were housed under 12 hours light-12 hours dark cycles, and the model of buccal squamous cell carcinoma was established by using the dimethylbenzanthracene (DMBA) to smear the golden hamster buccal mucosa. Before the DMBA was used and after DMBA was used 6 weeks and 14 weeks respectively, the golden hamsters were sacrificed at 6 different time points (5 rats per time point) within 24 hour, including 4, 8, 12, 16, 20 and 24 hour after lights onset (HALO), and the normal buccal mucosa, precancerous lesions and cancer tissue were obtained, respectively. HE stained sections were prepared to observe the canceration of each tissue. Real time RT-PCR was used to detect the mRNA expression of Per1, p53, CyclinD1, CDK1 and CyclinB1, and a cosine analysis method was applied to determine the circadian rhythm variation of Per1, p53, CyclinD1, CDK1 and CyclinB1 mRNA expression, which were characterized by median, amplitude and acrophase. The expression of Per1, p53, CDK1 and CyclinD1 mRNA in 6 different time points within 24 hours in the tissues of three different stages of carcinogenesis had circadian rhythm, respectively. However, the CyclinB1 mRNA was expressed with circadian rhythm just in normal and cancer tissue (P < 0.05), while in precancerous lesions the circadian rhythm was in disorder (P > 0.05). As the development of carcinoma, the median of Per1 and p53 mRNA expression were significantly decreased (P < 0.05), yet the median of CDK1, CyclinB1 and CyclinD1 mRNA expression were significantly increased (P < 0.05). The amplitude of Per1, p53 and CyclinD1 mRNA expression was significantly decreased as the development of carcinoma (P < 0.05), however the amplitude of CDK1 mRNA expression was significantly increased (P < 0.05). In addition, there was no significant difference in the amplitude of CyclinB1 mRNA expression. The time that the peak expression value of Per1 and CDK1 mRNA appeared (Acrophase) in precancerous lesions was remarkably earlier than that in normal tissues, but the acrophase of p53 and CyclinD1 mRNA expression was remarkably delayed. Moreover, the acrophase of CDK1 and CyclinB1 mRNA expression in cancer tissues was obviously earlier than that in normal tissues, yet there was no significant variation in acrophase of Per1, p53, CyclinD1 mRNA expression between normal tissues and cancer tissues. The circadian rhythm of clock gene Per1 and cell cycle genes p53, CyclinD1, CDK1, CyclinB1 expression remarkably varied with the occurrence and development of carcinoma. Further research into the interaction between circadian and cell cycle of two cycle activity and relationship with the carcinogenesis may providenew ideas and methods of individual treatment and the mechanism of carcinogenesis.

Correlation of cytoplasmic beta-catenin and cyclin D1 overexpression during thyroid carcinogenesis around Semipalatinsk nuclear test site.

PubMed

Meirmanov, Serik; Nakashima, Masahiro; Kondo, Hisayoshi; Matsufuji, Reiko; Takamura, Noboru; Ishigaki, Katsu; Ito, Masahiro; Prouglo, Yuri; Yamashita, Shunichi; Sekine, Ichiro

2003-06-01

The Semipalatinsk nuclear test site (SNTS), the Republic of Kazakhstan, has been contaminated by radioactive fallout. The alteration of oncogenic molecules in thyroid cancer around the SNTS was considered worthy of analysis because it presented the potential to elucidate the relationship between radiation exposure and thyroid cancer. This study aimed to analyze both beta-catenin and cyclin D1 expressions in thyroid carcinomas around the SNTS. We examined nine cases of chronic thyroiditis, eight cases of follicular adenomas, and 23 cases of papillary carcinomas. Immunohistochemically, all carcinomas displayed a strong cytosolic beta-catenin expression, while both chronic thyroiditis and follicular adenomas showed a significantly lower cytoplasmic beta-catenin (22.2% and 37.5%, respectively). No cyclin D1 immunoreactivity was evident in chronic thyroiditis. In contrast, 62.5% of follicular adenomas and 87.0% of papillary carcinoma showed cyclin D1 overexpression. Additionally, a strong correlation between cytoplasmic beta-catenin and cyclin D1 expression was suggested in thyroid tumors. This study revealed a higher prevalence of both aberrant beta-catenin expression and cyclin D1 overexpression in papillary thyroid cancers around the SNTS than sporadic cases. The analysis of the alteration of the Wnt signaling-related molecules in thyroid cancer around the SNTS may be important to gain an insight into radiation-induced thyroid tumorigenesis.

Dexamethasone Induces Cardiomyocyte Terminal Differentiation via Epigenetic Repression of Cyclin D2 Gene.

PubMed

Gay, Maresha S; Dasgupta, Chiranjib; Li, Yong; Kanna, Angela; Zhang, Lubo

2016-08-01

Dexamethasone treatment of newborn rats inhibited cardiomyocyte proliferation and stimulated premature terminal differentiation of cardiomyocytes in the developing heart. Yet mechanisms remain undetermined. The present study tested the hypothesis that the direct effect of glucocorticoid receptor-mediated epigenetic repression of cyclin D2 gene in the cardiomyocyte plays a key role in the dexamethasone-mediated effects in the developing heart. Cardiomyocytes were isolated from 2-day-old rats. Cells were stained with a cardiomyocyte marker α-actinin and a proliferation marker Ki67. Cyclin D2 expression was evaluated by Western blot and quantitative real-time polymerase chain reaction. Promoter methylation of CcnD2 was determined by methylated DNA immunoprecipitation (MeDIP). Overexpression of Cyclin D2 was conducted by transfection of FlexiCcnD2 (+CcnD2) construct. Treatment of cardiomyocytes isolated from newborn rats with dexamethasone for 48 hours significantly inhibited cardiomyocyte proliferation with increased binucleation and decreased cyclin D2 protein abundance. These effects were blocked with Ru486 (mifepristone). In addition, the dexamethasone treatment significantly increased cyclin D2 gene promoter methylation in newborn rat cardiomyocytes. 5-Aza-2'-deoxycytidine inhibited dexamethasone-mediated promoter methylation, recovered dexamethasone-induced cyclin D2 gene repression, and blocked the dexamethasone-elicited effects on cardiomyocyte proliferation and binucleation. In addition, the overexpression of cyclin D2 restored the dexamethasone-mediated inhibition of proliferation and increase in binucleation in newborn rat cardiomyocytes. The results demonstrate that dexamethasone acting on glucocorticoid receptors has a direct effect and inhibits proliferation and stimulates premature terminal differentiation of cardiomyocytes in the developing heart via epigenetic repression of cyclin D2 gene. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Dexamethasone Induces Cardiomyocyte Terminal Differentiation via Epigenetic Repression of Cyclin D2 Gene

PubMed Central

Gay, Maresha S.; Dasgupta, Chiranjib; Li, Yong; Kanna, Angela

2016-01-01

Dexamethasone treatment of newborn rats inhibited cardiomyocyte proliferation and stimulated premature terminal differentiation of cardiomyocytes in the developing heart. Yet mechanisms remain undetermined. The present study tested the hypothesis that the direct effect of glucocorticoid receptor-mediated epigenetic repression of cyclin D2 gene in the cardiomyocyte plays a key role in the dexamethasone-mediated effects in the developing heart. Cardiomyocytes were isolated from 2-day-old rats. Cells were stained with a cardiomyocyte marker α-actinin and a proliferation marker Ki67. Cyclin D2 expression was evaluated by Western blot and quantitative real-time polymerase chain reaction. Promoter methylation of CcnD2 was determined by methylated DNA immunoprecipitation (MeDIP). Overexpression of Cyclin D2 was conducted by transfection of FlexiCcnD2 (+CcnD2) construct. Treatment of cardiomyocytes isolated from newborn rats with dexamethasone for 48 hours significantly inhibited cardiomyocyte proliferation with increased binucleation and decreased cyclin D2 protein abundance. These effects were blocked with Ru486 (mifepristone). In addition, the dexamethasone treatment significantly increased cyclin D2 gene promoter methylation in newborn rat cardiomyocytes. 5-Aza-2'-deoxycytidine inhibited dexamethasone-mediated promoter methylation, recovered dexamethasone-induced cyclin D2 gene repression, and blocked the dexamethasone-elicited effects on cardiomyocyte proliferation and binucleation. In addition, the overexpression of cyclin D2 restored the dexamethasone-mediated inhibition of proliferation and increase in binucleation in newborn rat cardiomyocytes. The results demonstrate that dexamethasone acting on glucocorticoid receptors has a direct effect and inhibits proliferation and stimulates premature terminal differentiation of cardiomyocytes in the developing heart via epigenetic repression of cyclin D2 gene. PMID:27302109

Complexes of D-type cyclins with CDKs during maize germination

PubMed Central

Vázquez-Ramos, Jorge M.

2013-01-01

The importance of cell proliferation in plant growth and development has been well documented. The majority of studies on basic cell cycle mechanisms in plants have been at the level of gene expression and much less knowledge has accumulated in terms of protein interactions and activation. Two key proteins, cyclins and cyclin-dependent kinases (CDKs) are fundamental for cell cycle regulation and advancement. Our aim has been to understand the role of D-type cyclins and type A and B CDKs in the cell cycle taking place during a developmental process such as maize seed germination. Results indicate that three maize D-type cyclins—D2;2, D4;2, and D5;3—(G1-S cyclins by definition) bind and activate two different types of CDK—A and B1;1—in a differential way during germination. Whereas CDKA–D-type cyclin complexes are more active at early germination times than at later times, it was surprising to observe that CDKB1;1, a supposedly G2-M kinase, bound in a differential way to all D-type cyclins tested during germination. Binding to cyclin D2;2 was detectable at all germination times, forming a complex with kinase activity, whereas binding to D4;2 and D5;3 was more variable; in particular, D5;3 was only detected at late germination times. Results are discussed in terms of cell cycle advancement and its importance for seed germination. PMID:24127516

Restrictions in Cell Cycle Progression of Adult Vestibular Supporting Cells in Response to Ectopic Cyclin D1 Expression

PubMed Central

Loponen, Heidi; Ylikoski, Jukka; Albrecht, Jeffrey H.; Pirvola, Ulla

2011-01-01

Sensory hair cells and supporting cells of the mammalian inner ear are quiescent cells, which do not regenerate. In contrast, non-mammalian supporting cells have the ability to re-enter the cell cycle and produce replacement hair cells. Earlier studies have demonstrated cyclin D1 expression in the developing mouse supporting cells and its downregulation along maturation. In explant cultures of the mouse utricle, we have here focused on the cell cycle control mechanisms and proliferative potential of adult supporting cells. These cells were forced into the cell cycle through adenoviral-mediated cyclin D1 overexpression. Ectopic cyclin D1 triggered robust cell cycle re-entry of supporting cells, accompanied by changes in p27Kip1 and p21Cip1 expressions. Main part of cell cycle reactivated supporting cells were DNA damaged and arrested at the G2/M boundary. Only small numbers of mitotic supporting cells and rare cells with signs of two successive replications were found. Ectopic cyclin D1-triggered cell cycle reactivation did not lead to hyperplasia of the sensory epithelium. In addition, a part of ectopic cyclin D1 was sequestered in the cytoplasm, reflecting its ineffective nuclear import. Combined, our data reveal intrinsic barriers that limit proliferative capacity of utricular supporting cells. PMID:22073316

Restrictions in cell cycle progression of adult vestibular supporting cells in response to ectopic cyclin D1 expression.

PubMed

Loponen, Heidi; Ylikoski, Jukka; Albrecht, Jeffrey H; Pirvola, Ulla

2011-01-01

Sensory hair cells and supporting cells of the mammalian inner ear are quiescent cells, which do not regenerate. In contrast, non-mammalian supporting cells have the ability to re-enter the cell cycle and produce replacement hair cells. Earlier studies have demonstrated cyclin D1 expression in the developing mouse supporting cells and its downregulation along maturation. In explant cultures of the mouse utricle, we have here focused on the cell cycle control mechanisms and proliferative potential of adult supporting cells. These cells were forced into the cell cycle through adenoviral-mediated cyclin D1 overexpression. Ectopic cyclin D1 triggered robust cell cycle re-entry of supporting cells, accompanied by changes in p27(Kip1) and p21(Cip1) expressions. Main part of cell cycle reactivated supporting cells were DNA damaged and arrested at the G2/M boundary. Only small numbers of mitotic supporting cells and rare cells with signs of two successive replications were found. Ectopic cyclin D1-triggered cell cycle reactivation did not lead to hyperplasia of the sensory epithelium. In addition, a part of ectopic cyclin D1 was sequestered in the cytoplasm, reflecting its ineffective nuclear import. Combined, our data reveal intrinsic barriers that limit proliferative capacity of utricular supporting cells.

p14ARF Post-Transcriptional Regulation of Nuclear Cyclin D1 in MCF-7 Breast Cancer Cells: Discrimination between a Good and Bad Prognosis?

PubMed Central

McGowan, Eileen M.; Tran, Nham; Alling, Nikki; Yagoub, Daniel; Sedger, Lisa M.; Martiniello-Wilks, Rosetta

2012-01-01

As part of a cell’s inherent protection against carcinogenesis, p14ARF is upregulated in response to hyperproliferative signalling to induce cell cycle arrest. This property makes p14ARF a leading candidate for cancer therapy. This study explores the consequences of reactivating p14ARF in breast cancer and the potential of targeting p14ARF in breast cancer treatment. Our results show that activation of the p14ARF-p53-p21-Rb pathway in the estrogen sensitive MCF-7 breast cancer cells induces many hallmarks of senescence including a large flat cell morphology, multinucleation, senescence-associated-β-gal staining, and rapid G1 and G2/M phase cell cycle arrest. P14ARF also induces the expression of the proto-oncogene cyclin D1, which is most often associated with a transition from G1-S phase and is highly expressed in breast cancers with poor clinical prognosis. In this study, siRNA knockdown of cyclin D1, p21 and p53 show p21 plays a pivotal role in the maintenance of high cyclin D1 expression, cell cycle and growth arrest post-p14ARF induction. High p53 and p14ARF expression and low p21/cyclin D1 did not cause cell-cycle arrest. Knockdown of cyclin D1 stops proliferation but does not reverse senescence-associated cell growth. Furthermore, cyclin D1 accumulation in the nucleus post-p14ARF activation correlated with a rapid loss of nucleolar Ki-67 protein and inhibition of DNA synthesis. Latent effects of the p14ARF-induced cellular processes resulting from high nuclear cyclin D1 accumulation included a redistribution of Ki-67 into the nucleoli, aberrant nuclear growth (multinucleation), and cell proliferation. Lastly, downregulation of cyclin D1 through inhibition of ER abrogated latent recurrence. The mediation of these latent effects by continuous expression of p14ARF further suggests a novel mechanism whereby dysregulation of cyclin D1 could have a double-edged effect. Our results suggest that p14ARF induced-senescence is related to late-onset breast cancer in estrogen responsive breast cancers and/or the recurrence of more aggressive breast cancer post-therapy. PMID:22860097

Expression of retinoblastoma gene product (pRb) in mantle cell lymphomas. Correlation with cyclin D1 (PRAD1/CCND1) mRNA levels and proliferative activity.

PubMed Central

Jares, P.; Campo, E.; Pinyol, M.; Bosch, F.; Miquel, R.; Fernandez, P. L.; Sanchez-Beato, M.; Soler, F.; Perez-Losada, A.; Nayach, I.; Mallofré, C.; Piris, M. A.; Montserrat, E.; Cardesa, A.

1996-01-01

Mantle cell lymphomas (MCLs) are molecularly characterized by bcl-1 rearrangement and constant cyclin D1 (PRAD-1/CCND1) gene overexpression. Cyclin D1 is a G1 cyclin that participates in the control of the cell cycle progression by interacting with the retinoblastoma gene product (pRb). Inactivation of the Rb tumor suppressor gene has been implicated in the development of different types of human tumors including some high grade non-Hodgkin's lymphomas. To determine the role of the retinoblastoma gene in the pathogenesis of MCLs and its possible interaction with cyclin D1, pRb expression was examined in 23 MCLs including 17 typical and 6 blastic variants by immunohistochemistry and Western blot. Rb gene structure was studied in 13 cases by Southern blot. Cytogenetic analysis was performed in 5 cases. The results were compared with the cyclin D1 mRNA levels examined by Northern analysis, and the proliferative activity of the tumors was measured by Ki-67 growth fraction and flow cytometry. pRb was expressed in all MCLs. The expression varied from case to case (mean, 14.1% of positive cells; range, 1.3 to 42%) with a significant correlation with the proliferative activity of the tumors (mitotic index r = 0.85; Ki-67 r = 0.7; S phase = 0.73). Blastic variants showed higher numbers of pRb-positive cells (mean, 29%) than the typical cases (10%; P < 0.005) by immunohistochemistry and, concordantly, higher levels of expression by Western blot. In addition, the blastic cases also had an increased expression of the phosphorylated protein. No alterations in Rb gene structure were observed by Southern blot analysis. Cyclin D1 mRNA levels were independent of pRb expression and the proliferative activity of the tumors. These findings suggest that pRb in MCLs is normally regulated in relation to the proliferative activity of the tumors. Cyclin D1 overexpression may play a role in the maintenance of cell proliferation by overcoming the suppressive growth control of pRb. Images Figure 1 Figure 2 Figure 4 PMID:8623927

Glycogen synthase kinase 3 has a limited role in cell cycle regulation of cyclin D1 levels.

PubMed

Yang, Ke; Guo, Yang; Stacey, William C; Harwalkar, Jyoti; Fretthold, Jonathan; Hitomi, Masahiro; Stacey, Dennis W

2006-08-30

The expression level of cyclin D1 plays a vital role in the control of proliferation. This protein is reported to be degraded following phosphorylation by glycogen synthase kinase 3 (GSK3) on Thr-286. We recently showed that phosphorylation of Thr-286 is responsible for a decline in cyclin D1 levels during S phase, an event required for efficient DNA synthesis. These studies were undertaken to test the possibility that phosphorylation by GSK3 is responsible for the S phase specific decline in cyclin D1 levels, and that this event is regulated by the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway which controls GSK3. We found, however, that neither PI3K, AKT, GSK3, nor proliferative signaling activity in general is responsible for the S phase decline in cyclin D1 levels. In fact, the activity of these signaling kinases does not vary through the cell cycle of proliferating cells. Moreover, we found that GSK3 activity has little influence over cyclin D1 expression levels during any cell cycle phase. Inhibition of GSK3 activity by siRNA, LiCl, or other chemical inhibitors failed to influence cyclin D1 phosphorylation on Thr-286, even though LiCl efficiently blocked phosphorylation of beta-catenin, a known substrate of GSK3. Likewise, the expression of a constitutively active GSK3 mutant protein failed to influence cyclin D1 phosphorylation or total protein expression level. Because we were unable to identify any proliferative signaling molecule or pathway which is regulated through the cell cycle, or which is able to influence cyclin D1 levels, we conclude that the suppression of cyclin D1 levels during S phase is regulated by cell cycle position rather than signaling activity. We propose that this mechanism guarantees the decline in cyclin D1 levels during each S phase; and that in so doing it reduces the likelihood that simple over expression of cyclin D1 can lead to uncontrolled cell growth.

[Effects of Biejiajian Pills on Wnt signal pathway signal molecules β-catenin/TCF4 complex activities and downstream proteins cyclin D1 and MMP-2 in hepatocellular carcinoma cells].

PubMed

Wen, Bin; Sun, Haitao; He, Songqi; Cheng, Yang; Jia, Wenyan; Fan, Eryan; Pang, Jie

2014-12-01

To study the effect of Biejiajian Pills on Wnt signal pathway and the mechanisms underlying its action to suppress the invasiveness of hepatocellular carcinoma. HepG2 cells cultured in the serum of rats fed with Biejiajian Pills for 48 h were examined for β-catenin expression using immunofluorescence, β-catenin/TCF4 complex activity with luciferase, and expressions of the downstream proteins cyclin D1 and MMP-2 using qRT-PCR. Biejiajian Pills-treated sera significantly reduced the expressions of cytoplasmic and nuclear β-catenin protein, cyclin D1 and MMP-2 proteins and lowered the activities of β-catenin/TCF4 complex. Biejiajian Pills may serve as a potential anti-tumor agent, whose effect might be mediated by inhibiting the Wnt/β-catenin pathway.

Glucose Induces Mouse β-Cell Proliferation via IRS2, MTOR, and Cyclin D2 but Not the Insulin Receptor

PubMed Central

Stamateris, Rachel E.; Sharma, Rohit B.; Kong, Yahui; Ebrahimpour, Pantea; Panday, Deepika; Ranganath, Pavana; Zou, Baobo; Levitt, Helena; Parambil, Nisha Abraham; O’Donnell, Christopher P.; García-Ocaña, Adolfo

2016-01-01

An important goal in diabetes research is to understand the processes that trigger endogenous β-cell proliferation. Hyperglycemia induces β-cell replication, but the mechanism remains debated. A prime candidate is insulin, which acts locally through the insulin receptor. Having previously developed an in vivo mouse hyperglycemia model, we tested whether glucose induces β-cell proliferation through insulin signaling. By using mice lacking insulin signaling intermediate insulin receptor substrate 2 (IRS2), we confirmed that hyperglycemia-induced β-cell proliferation requires IRS2 both in vivo and ex vivo. Of note, insulin receptor activation was not required for glucose-induced proliferation, and insulin itself was not sufficient to drive replication. Glucose and insulin caused similar acute signaling in mouse islets, but chronic signaling differed markedly, with mammalian target of rapamycin (MTOR) and extracellular signal–related kinase (ERK) activation by glucose and AKT activation by insulin. MTOR but not ERK activation was required for glucose-induced proliferation. Cyclin D2 was necessary for glucose-induced β-cell proliferation. Cyclin D2 expression was reduced when either IRS2 or MTOR signaling was lost, and restoring cyclin D2 expression rescued the proliferation defect. Human islets shared many of these regulatory pathways. Taken together, these results support a model in which IRS2, MTOR, and cyclin D2, but not the insulin receptor, mediate glucose-induced proliferation. PMID:26740601

Altered expression of key cell cycle regulators in renal cell carcinoma associated with Xp11.2 translocation.

PubMed

Barroca, H; Castedo, S; Vieira, J; Teixeira, M; Müller-Höcker, J

2009-01-01

Renal cell carcinoma (RCC) is a rare tumor in the pediatric population. Recently, a phenotypically and genetically distinct kidney carcinoma, mainly prevalent in children and associated with an Xp11.2 translocation or TFE3 gene fusion, has been described. It has been advanced that in this subtype of RCC, there is an accumulation of cyclin D1, cyclin D3, and p21 ((wafl/cip1)). The aim of the present study was to figure out in two pediatric RCC recently diagnosed in our department (one clear cell-type RCC and one TFE3-positive RCC) whether those features are indeed specific of the latter tumor or occur in pediatric RCC irrespective of the tumor type. The following immunostains were performed in both cases: Ki67, p16(ink4a), p21 ((wafl/cip1)), p27(kip1), p53, p63, mdm2, cyclin D1, cyclin D3, TFE3, CD10, vimentin, E-cadherin, and RCC-antigen. We observed in the TFE3-positive carcinoma an intense immunoreaction for p21 ((wafl/cip1)), cyclin D1, and cyclin D3, without expression for p53, p16, p27(kip1), and mdm2, whereas the immunoexpression profile observed in the classic RCC was similar to that of clear cell, adult-type RCC. Our study confirms that TFE3-positive RCC exhibits a deregulation of the cell cycle apparently unrelated to the young age of the patients.

The ciliary margin zone of the mammalian retina generates retinal ganglion cells

PubMed Central

Marcucci, Florencia; Murcia-Belmonte, Veronica; Coca, Yaiza; Ferreiro-Galve, Susana; Wang, Qing; Kuwajima, Takaaki; Khalid, Sania; Ross, M. Elizabeth; Herrera, Eloisa; Mason, Carol

2016-01-01

Summary The retina of lower vertebrates grows continuously by integrating new neurons generated from progenitors in the ciliary margin zone (CMZ). Whether the mammalian CMZ provides the neural retina with retinal cells is controversial. Live-imaging of embryonic retina expressing eGFP in the CMZ shows that cells migrate laterally from the CMZ to the neural retina where differentiated retinal ganglion cells (RGCs) reside. As Cyclin D2, a cell-cycle regulator, is enriched in ventral CMZ, we analyzed Cyclin D2−/− mice to test whether the CMZ is a source of retinal cells. Neurogenesis is diminished in Cyclin D2 mutants, leading to a reduction of RGCs in the ventral retina. In line with these findings, in the albino retina, the decreased production of ipsilateral RGCs is correlated with fewer Cyclin D2+ cells. Together, these results implicate the mammalian CMZ as a neurogenic site that produces RGCs and whose proper generation depends on Cyclin D2 activity. PMID:28009286

The Ciliary Margin Zone of the Mammalian Retina Generates Retinal Ganglion Cells.

PubMed

Marcucci, Florencia; Murcia-Belmonte, Veronica; Wang, Qing; Coca, Yaiza; Ferreiro-Galve, Susana; Kuwajima, Takaaki; Khalid, Sania; Ross, M Elizabeth; Mason, Carol; Herrera, Eloisa

2016-12-20

The retina of lower vertebrates grows continuously by integrating new neurons generated from progenitors in the ciliary margin zone (CMZ). Whether the mammalian CMZ provides the neural retina with retinal cells is controversial. Live imaging of embryonic retina expressing eGFP in the CMZ shows that cells migrate laterally from the CMZ to the neural retina where differentiated retinal ganglion cells (RGCs) reside. Because Cyclin D2, a cell-cycle regulator, is enriched in ventral CMZ, we analyzed Cyclin D2 -/- mice to test whether the CMZ is a source of retinal cells. Neurogenesis is diminished in Cyclin D2 mutants, leading to a reduction of RGCs in the ventral retina. In line with these findings, in the albino retina, the decreased production of ipsilateral RGCs is correlated with fewer Cyclin D2 + cells. Together, these results implicate the mammalian CMZ as a neurogenic site that produces RGCs and whose proper generation depends on Cyclin D2 activity. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Cyclin D2 in the basal process of neural progenitors is linked to non-equivalent cell fates

PubMed Central

Tsunekawa, Yuji; Britto, Joanne M; Takahashi, Masanori; Polleux, Franck; Tan, Seong-Seng; Osumi, Noriko

2012-01-01

Asymmetric cell division plays an indispensable role during corticogenesis for producing new neurons while maintaining a self-renewing pool of apical progenitors. The cellular and molecular determinants favouring asymmetric division are not completely understood. Here, we identify a novel mechanism for generating cellular asymmetry through the active transportation and local translation of Cyclin D2 mRNA in the basal process. This process is regulated by a unique cis-regulatory sequence found in the 3′ untranslated region (3′UTR) of the mRNA. Unequal inheritance of Cyclin D2 protein to the basally positioned daughter cell with the basal process confers renewal of the apical progenitor after asymmetric division. Conversely, depletion of Cyclin D2 in the apically positioned daughter cell results in terminal neuronal differentiation. We demonstrate that Cyclin D2 is also expressed in the developing human cortex within similar domains, thus indicating that its role as a fate determinant is ancient and conserved. PMID:22395070

DACH1 regulates cell cycle progression of myeloid cells through the control of cyclin D, Cdk 4/6 and p21{sup Cip1}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Jae-Woong; Kim, Hyeng-Soo; Kim, Seonggon

2012-03-30

Highlights: Black-Right-Pointing-Pointer DACH1 increases cyclin D, F and Cdk 1, 4, 6 in mouse myeloid progenitor cells. Black-Right-Pointing-Pointer The knockdown of DACH1 blocked the cell cycle progression of HL-60 cells. Black-Right-Pointing-Pointer The novel effect of DACH1 related with cell cycle regulation and leukemogenesis. -- Abstract: The cell-fate determination factor Dachshund, a component of the Retinal Determination Gene Network (RDGN), has a role in breast tumor proliferation through the repression of cyclin D1 and several key regulators of embryonic stem cell function, such as Nanog and Sox2. However, little is known about the role of DACH1 in a myeloid lineage asmore » a cell cycle regulator. Here, we identified the differential expression levels of extensive cell cycle regulators controlled by DACH1 in myeloid progenitor cells. The forced expression of DACH1 induced p27{sup Kip1} and repressed p21{sup Cip1}, which is a pivotal characteristic of the myeloid progenitor. Furthermore, DACH1 significantly increased the expression of cyclin D1, D3, F, and Cdk 1, 4, and 6 in myeloid progenitor cells. The knockdown of DACH1 blocked the cell cycle progression of HL-60 promyeloblastic cells through the decrease of cyclin D1, D3, F, and Cdk 1, 4, and 6 and increase in p21{sup Cip1}, which in turn decreased the phosphorylation of the Rb protein. The expression of Sox2, Oct4, and Klf4 was significantly up-regulated by the forced expression of DACH1 in mouse myeloid progenitor cells.« less

Gossypol inhibition of mitosis, cyclin D1 and Rb protein in human mammary cancer cells and cyclin-D1 transfected human fibrosarcoma cells.

PubMed Central

Ligueros, M.; Jeoung, D.; Tang, B.; Hochhauser, D.; Reidenberg, M. M.; Sonenberg, M.

1997-01-01

The antiproliferative effects of gossypol on human MCF-7 mammary cancer cells and cyclin D1-transfected HT-1060 human fibrosarcoma cells were investigated by cell cycle analysis and effects on the cell cycle regulatory proteins Rb and cyclin D1. Flow cytometry of MCF-7 cells at 24 h indicated that 10 microM gossypol inhibited DNA synthesis by producing a G1/S block. Western blot analysis using anti-human Rb antibodies and anti-human cyclin D1 antibodies in MCF-7 cells and high- and low-expression cyclin D1-transfected fibrosarcoma cells indicated that, after 6 h exposure, gossypol decreased the expression levels of these proteins in a dose-dependent manner. Gossypol also decreased the ratio of phosphorylated to unphosphorylated Rb protein in human mammary cancer and fibrosarcoma cell lines. Gossypol (10 microM) treated also decreased cyclin D1-associated kinase activity on histone H1 used as a substrate in MCF-7 cells. These results suggest that gossypol might suppress growth by modulating the expression of cell cycle regulatory proteins Rb and cyclin D1 and the phosphorylation of Rb protein. Images Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 PMID:9218727

Cyclin d1 expression in odontogenic cysts.

PubMed

Taghavi, Nasim; Modabbernia, Shirin; Akbarzadeh, Alireza; Sajjadi, Samad

2013-01-01

In the present study expression of cyclin D1 in the epithelial lining of odontogenic keratocyst, radicular cyst, dentigerous cyst and glandular odontogenic cyst was investigated to compare proliferative activity in these lesions. Immunohistochemical staining of cyclin D1 on formalin-fixed, paraffin-embedded tissue sections of odontogenic keratocysts (n=23), dentigerous cysts (n=20), radicular cysts (n=20) and glandular odontogenic cysts (n=5) was performed by standard EnVision method. Then, slides were studied to evaluate the following parameters in epithelial lining of cysts: expression, expression pattern, staining intensity and localization of expression. The data analysis showed statistically significant difference in cyclin D1 expression in studied groups (p < 0.001). Assessment of staining intensity and staining pattern showed more strong intensity and focally pattern in odontogenic keratocysts, but difference was not statistically significant among groups respectively (p=0.204, 0.469). Considering expression localization, cyclin D1 positive cells in odontogenic keratocysts and dentigerous cysts were frequently confined in parabasal layer, different from radicular cysts and glandular odontogenic cysts. The difference was statistically significant (p < 0.01). Findings showed higher expression of cyclin D1 in parabasal layer of odontogenic keratocyst and the entire cystic epithelium of glandular odontogenic cysts comparing to dentigerous cysts and radicular cysts, implying the possible role of G1-S cell cycle phase disturbances in the aggressiveness of odontogenic keratocyst and glandular odontogenic cyst.

Lapatinib-resistant cancer cells possessing epithelial cancer stem cell properties develop sensitivity during sphere formation by activation of the ErbB/AKT/cyclin D2 pathway.

PubMed

Ohnishi, Yuichi; Yasui, Hiroki; Kakudo, Kenji; Nozaki, Masami

2016-11-01

Lapatinib, a dual inhibitor of epidermal growth factor receptor (EGFR)/ErbB2, has antiproliferative effects and is used to treat patients with ErbB2-positive metastatic breast cancer. In the present study, we examined the effects of lapatinib on growth of oral and prostate cancer cells. Oral squamous cell carcinoma (OSCC) cell lines HSC3, HSC4 and Ca9-22 were sensitive to the antiproliferative effects of lapatinib in anchorage-dependent culture, but the OSCC cell lines KB and SAS and the prostate cancer cell line DU145 were resistant to lapatinib. Phosphorylation levels of EGFR in all cell lines decreased during lapatinib treatment in anchorage‑dependent culture. Furthermore, the phosphorylation levels of ErbB2, ErbB3 and Akt and the protein levels of cyclin D1 were decreased by lapatinib treatment of HSC3, HSC4 and Ca9-22 cells. ErbB3 was not expressed and cyclin D1 protein levels were not altered by lapatinib treatment in KB, DU145 and SAS cells. The phosphorylation of ErbB2 and AKT was not affected by lapatinib in SAS cells and was not detected in KB and DU145 cells. Lapatinib-resistant cell lines exhibited sphere-forming ability, and SAS cells developed sensitivity to lapatinib during sphere formation. The phosphorylation levels of ErbB2 and AKT and protein levels of cyclin D2 increased during sphere formation of SAS cells and decreased with lapatinib treatment. In addition, sphere formation of SAS cells was inhibited by the AKT inhibitor MK2206. AKT phosphorylation and cyclin D2 levels in SAS spheres were decreased by MK2206 treatment. SAS cells expressed E-cadherin, but not vimentin and KB cells expressed vimentin, but not E-cadherin. DU145 cells expressed vimentin and E-cadherin. These results suggested that phosphorylation of EGFR and ErbB2 by cell detachment from the substratum induces the AKT pathway/cyclin D2-dependent sphere growth in SAS epithelial cancer stem-like cells, thereby rendering SAS spheres sensitive to lapatinib treatment.

Vitex rotundifolia Fruit Suppresses the Proliferation of Human Colorectal Cancer Cells through Down-regulation of Cyclin D1 and CDK4 via Proteasomal-Dependent Degradation and Transcriptional Inhibition.

PubMed

Song, Hun Min; Park, Gwang Hun; Park, Su Bin; Kim, Hyun-Seok; Son, Ho-Jun; Um, Yurry; Jeong, Jin Boo

2018-01-01

Viticis Fructus (VF) as the dried fruit from Vitex rotundifolia L. used as a traditional medicine for treating inflammation, headache, migraine, chronic bronchitis, eye pain, and gastrointestinal infections has been reported to have antiproliferative effects against various cancer cells, including breast, lung and colorectal cancer cells. However, the molecular mechanisms by which VF mediates the inhibitory effect of the proliferation of cancer cells have not been elucidated in detail. In this study, we investigated the molecular mechanism of VF on the down-regulation of cyclin D1 and CDK4 level associated with cancer cell proliferation. VF suppressed the proliferation of human colorectal cancer cell lines such as HCT116 and SW480. VF induced decrease in cyclin D1 and CDK4 in both protein and mRNA levels. However, the protein levels of cyclin D1 and CDK4 were decreased by VF at an earlier time than the change of mRNA levels; rather it suppressed the expression of cyclin D1 and CDK4 via the proteasomal degradation. In cyclin D1 and CDK4 degradation, we found that Thr286 phosphorylation of cyclin D1 plays a pivotal role in VF-mediated cyclin D1 degradation. Subsequent experiments with several kinase inhibitors suggest that VF-mediated degradation of cyclin D1 may be dependent on GSK3[Formula: see text] and VF-mediated degradation of CDK4 is dependent on ERK1/2, p38 and GSK3[Formula: see text]. In the transcriptional regulation of cyclin D1 and CDK4, we found that VF inhibited Wnt activation associated with cyclin D1 transcriptional regulation through TCF4 down-regulation. In addition, VF treatment down-regulated c-myc expression associated CDK4 transcriptional regulation. Our results suggest that VF has potential to be a candidate for the development of chemoprevention or therapeutic agents for human colorectal cancer.

Attenuation of p38-Mediated miR-1/133 Expression Facilitates Myoblast Proliferation during the Early Stage of Muscle Regeneration

PubMed Central

Zhang, Duo; Li, Xihua; Chen, Chuchu; Li, Yuyin; Zhao, Lei; Jing, Yanyan; Liu, Wei; Wang, Xiaoyun; Zhang, Ying; Xia, Hongfeng; Chang, Yaning; Gao, Xiang; Yan, Jun; Ying, Hao

2012-01-01

Myoblast proliferation following myotrauma is regulated by multiple factors including growth factors, signal pathways, transcription factors, and miRNAs. However, the molecular mechanisms underlying the orchestration of these regulatory factors remain unclear. Here we show that p38 signaling is required for miR-1/133a clusters transcription and both p38 activity and miR-1/133 expression are attenuated during the early stage of muscle regeneration in various animal models. Additionally, we show that both miR-1 and miR-133 reduce Cyclin D1 expression and repress myoblast proliferation by inducing G1 phase arrest. Furthermore, we demonstrate that miR-133 inhibits mitotic progression by targeting Sp1, which mediates Cyclin D1 transcription, while miR-1 suppresses G1/S phase transition by targeting Cyclin D1. Finally, we reveal that proproliferative FGF2, which is elevated during muscle regeneration, attenuates p38 signaling and miR-1/133 expression. Taken together, our results suggest that downregulation of p38-mediated miR-1/133 expression by FGF2 and subsequent upregulation of Sp1/Cyclin D1 contribute to the increased myoblast proliferation during the early stage of muscle regeneration. PMID:22911796

Attenuation of p38-mediated miR-1/133 expression facilitates myoblast proliferation during the early stage of muscle regeneration.

PubMed

Zhang, Duo; Li, Xihua; Chen, Chuchu; Li, Yuyin; Zhao, Lei; Jing, Yanyan; Liu, Wei; Wang, Xiaoyun; Zhang, Ying; Xia, Hongfeng; Chang, Yaning; Gao, Xiang; Yan, Jun; Ying, Hao

2012-01-01

Myoblast proliferation following myotrauma is regulated by multiple factors including growth factors, signal pathways, transcription factors, and miRNAs. However, the molecular mechanisms underlying the orchestration of these regulatory factors remain unclear. Here we show that p38 signaling is required for miR-1/133a clusters transcription and both p38 activity and miR-1/133 expression are attenuated during the early stage of muscle regeneration in various animal models. Additionally, we show that both miR-1 and miR-133 reduce Cyclin D1 expression and repress myoblast proliferation by inducing G1 phase arrest. Furthermore, we demonstrate that miR-133 inhibits mitotic progression by targeting Sp1, which mediates Cyclin D1 transcription, while miR-1 suppresses G1/S phase transition by targeting Cyclin D1. Finally, we reveal that proproliferative FGF2, which is elevated during muscle regeneration, attenuates p38 signaling and miR-1/133 expression. Taken together, our results suggest that downregulation of p38-mediated miR-1/133 expression by FGF2 and subsequent upregulation of Sp1/Cyclin D1 contribute to the increased myoblast proliferation during the early stage of muscle regeneration.

Expression variations of connective tissue growth factor in pulmonary arteries from smokers with and without chronic obstructive pulmonary disease

PubMed Central

Zhou, Si-jing; Li, Min; Zeng, Da-xiong; Zhu, Zhong-ming; Hu, Xian-Wei; Li, Yong-huai; Wang, Ran; Sun, Geng-yun

2015-01-01

Cigarette smoking contributes to the development of pulmonary hypertension (PH) complicated with chronic obstructive pulmonary disease (COPD), and the pulmonary vascular remodeling, the structural basis of PH, could be attributed to abnormal proliferation of pulmonary artery smooth muscle cells (PASMCs).In this study, morphometrical analysis showed that the pulmonary vessel wall thickness in smoker group and COPD group was significantly greater than in nonsmokers. In addition, we determined the expression patterns of connective tissue growth factor (CTGF) and cyclin D1 in PASMCs harvested from smokers with normal lung function or mild to moderate COPD, finding that the expression levels of CTGF and cyclin D1 were significantly increased in smoker group and COPD group. In vitro experiment showed that the expression of CTGF, cyclin D1 and E2F were significantly increased in human PASMCs (HPASMCs) treated with 2% cigarette smoke extract (CSE), and two CTGF siRNAs with different mRNA hits successfully attenuated the upregulated cyclin D1 and E2F, and significantly restored the CSE-induced proliferation of HPASMCs by causing cell cycle arrest in G0. These findings suggest that CTGF may contribute to the pathogenesis of abnormal proliferation of HPASMCs by promoting the expression of its downstream effectors in smokers with or without COPD. PMID:25708588

[Relationship between the expression of beta-cat, cyclin D1 and c-myc and the occurance and biological behavior of pancreatic cancer].

PubMed

Li, Yu-jun; Ji, Xiang-rui

2003-06-01

To study the relationship between the abnormal expression of beta-catenin (beta-cat) and the high expressions of cyclin D1 and c-myc and the occurance, proliferation, infiltration, metastasis and prognosis of pancreatic cancer, and to provide rational basis for the clinical diagnosis and treatment. Immunohistochemical PicTure trade mark was used to examine the expressions of beta-cat, cyclin D1 and c-myc in 47 cases of the cancerous tissue of pancreas, 12 cases of the pancreatic intraepithelial neoplasia and 10 cases of normal tissue of pancreas, respectively. Pancreatic cancer proliferation cell nuclear antigen (PCNA) was also tested as the index of the extent of proliferation of the pancreatic cancer. beta-cat was expressed normally in the 10 cases of the normal pancreatic tissue, while cyclin D1 and c-myc were negative. The expression rates of beta-cat, cyclin D1 and c-myc in the tissues of the pancreatic intraepithelial neoplasia and the pancreatic cancer had no significant difference [6/12 and 68.1% (32/47), 6/12 and 74.5% (35/47), 5/12 and 70.2% (33/47) respectively;P values were all more than 0.05]. The abnormal expression rate of beta-cat was significantly correlated to the metastasis of the pancreatic cancer and the one-year survival rate (both P < 0.05), but had no relation with the size, the extent of differentiation, the activity of proliferation, or infiltration of the pancreatic cancer (both P > 0.05). The expression rate of cyclin D1 was correlated with the proliferation of the pancreatic cancer and the extent of differentiation (both P < 0.05), but not with the size, infiltration, metastasis, or one-year survival rate of the pancreatic cancer (both P > 0.05). The expression rate of c-myc was not correlated with the size, the extent of proliferation, infiltration, metastasis, or one-year survival rate (both P > 0.05), but closely with the proliferation activity of the cancerous tissue of pancreas (P < 0.05). The abnormal expression of beta-cat and the high expressions of cyclin D1 and c-myc had a parallel relationship with the pancreatic intraepithelial neoplasia and pancreatic cancer (both P < 0.05, gamma = 1.000, 0.845, 0.437, 0.452). The abnormal expression of beta-cat activates cyclin D1 and c-myc, and results in the unchecked proliferation and differentiation, which may play an important role in the genesis of the pancreatic cancer. The abnormal expression of beta-cat is one of the mechanisms for the spread of pancreatic cancer and an index in the molecular biology to determine the metastasis and prognosis of pancreatic cancer.

The p-ERK–p-c-Jun–cyclinD1 pathway is involved in proliferation of smooth muscle cells after exposure to cigarette smoke extract

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Tianjia; Song, Ting; Ni, Leng

Highlights: • Smooth muscle cells proliferated after exposure to cigarette smoke extract. • The p-ERK, p-c-Jun, and cyclinD1 expressions increased in the process. • The p-ERK inhibitor, U0126, can reverse these effects. • The p-ERK → p-c-Jun → cyclinD1 pathway is involved in the process. - Abstract: An epidemiological survey has shown that smoking is closely related to atherosclerosis, in which excessive proliferation of vascular smooth muscle cells (SMCs) plays a key role. To investigate the mechanism underlying this unusual smoking-induced proliferation, cigarette smoke extract (CSE), prepared as smoke-bubbled phosphate-buffered saline (PBS), was used to induce effects mimicking those exertedmore » by smoking on SMCs. As assessed by Cell Counting Kit-8 detection (an improved MTT assay), SMC viability increased significantly after exposure to CSE. Western blot analysis demonstrated that p-ERK, p-c-Jun, and cyclinD1 expression increased. When p-ERK was inhibited using U0126 (inhibitor of p-ERK), cell viability decreased and the expression of p-c-Jun and cyclinD1 was reduced accordingly, suggesting that p-ERK functions upstream of p-c-Jun and cyclinD1. When a c-Jun over-expression plasmid was transfected into SMCs, the level of cyclinD1 in these cells increased. Moreover, when c-Jun was knocked down by siRNA, cyclinD1 levels decreased. In conclusion, our findings indicate that the p-ERK–p-c-Jun–cyclinD1 pathway is involved in the excessive proliferation of SMCs exposed to CSE.« less

Cyclin D1 Determines Mitochondrial Function In Vivo†

PubMed Central

Sakamaki, Toshiyuki; Casimiro, Mathew C.; Ju, Xiaoming; Quong, Andrew A.; Katiyar, Sanjay; Liu, Manran; Jiao, Xuanmao; Li, Anping; Zhang, Xueping; Lu, Yinan; Wang, Chenguang; Byers, Stephen; Nicholson, Robert; Link, Todd; Shemluck, Melvin; Yang, Jianguo; Fricke, Stanley T.; Novikoff, Phyllis M.; Papanikolaou, Alexandros; Arnold, Andrew; Albanese, Christopher; Pestell, Richard

2006-01-01

The cyclin D1 gene encodes a regulatory subunit of the holoenzyme that phosphorylates and inactivates the pRb tumor suppressor to promote nuclear DNA synthesis. cyclin D1 is overexpressed in human breast cancers and is sufficient for the development of murine mammary tumors. Herein, cyclin D1 is shown to perform a novel function, inhibiting mitochondrial function and size. Mitochondrial activity was enhanced by genetic deletion or antisense or small interfering RNA to cyclin D1. Global gene expression profiling and functional analysis of mammary epithelial cell-targeted cyclin D1 antisense transgenics demonstrated that cyclin D1 inhibits mitochondrial activity and aerobic glycolysis in vivo. Reciprocal regulation of these genes was observed in cyclin D1-induced mammary tumors. Cyclin D1 thus integrates nuclear DNA synthesis and mitochondrial function. PMID:16809779

Cyclin D1 and Ewing's sarcoma/PNET: A microarray analysis.

PubMed

Fagone, Paolo; Nicoletti, Ferdinando; Salvatorelli, Lucia; Musumeci, Giuseppe; Magro, Gaetano

2015-10-01

Recent immunohistochemical analyses have showed that cyclin D1 is expressed in soft tissue Ewing's sarcoma/peripheral neuroectodermal tumor (PNET) of childhood and adolescents, while it is undetectable in both embryonal and alveolar rhabdomyosarcoma. In the present paper, microarray analysis provided evidence of a significant upregulation of cyclin D1 in Ewing's sarcoma as compared to normal tissues. In addition, we confirmed our previous findings of a significant over-expression of cyclin D1 in Ewing sarcoma as compared to rhabdomyosarcoma. Bioinformatic analysis also allowed to identify some other genes, strongly correlated to cyclin D1, which, although not previously studied in pediatric tumors, could represent novel markers for the diagnosis and prognosis of Ewing's sarcoma/PNET. The data herein provided support not only the use of cyclin D1 as a diagnostic marker of Ewing sarcoma/PNET but also the possibility of using drugs targeting cyclin D1 as potential therapeutic strategies. Copyright © 2015 Elsevier GmbH. All rights reserved.

Taraxasterol suppresses the growth of human liver cancer by upregulating Hint1 expression.

PubMed

Bao, Tianhao; Ke, Yang; Wang, Yifan; Wang, Weiwei; Li, Yuehua; Wang, Yan; Kui, Xiang; Zhou, Qixin; Zhou, Han; Zhang, Cheng; Zhou, Dongming; Wang, Lin; Xiao, Chunjie

2018-07-01

Taraxasterol has potent anti-inflammatory and anti-tumor activity. However, the effect and potential mechanisms of Taraxasterol on the growth of human liver cancer have not been clarified. Histidine triad nucleotide-binding protein 1 (Hint1) is a tumor suppressor and its downregulated expression is associated with the development of cancer. Here, we report that Taraxasterol treatment significantly suppressed cell proliferation and induced cell cycle arrest at G0/G1 phase and apoptosis in liver cancer cells, but not in non-tumor hepatocytes. Furthermore, Taraxasterol upregulated Hint1 and Bax, but downregulated Bcl2 and cyclin D1 expression, accompanied by promoting the demethylation in the Hint1 promoter region in liver cancer cells. The effects of Taraxasterol were abrogated by Hint1 silencing and partially mitigated by Bax silencing, Bcl2 or cyclin D1 over-expression in HepG2 cells. Moreover, oral administration with Taraxasterol did not affect body weight, urinary protein levels, and the heart, liver, and kidney morphology in BALB/c mice but effectively inhibited the growth of implanted SK-Hep1 tumor in vivo. Collectively, we demonstrate that Taraxasterol inhibits the growth of liver cancer at least partially by enhancing Hint1 expression to regulate Bax, Bcl2, and cyclin D1 expression. Taraxasterol may be a drug candidate for the treatment of human liver cancer. Taraxasterol inhibits growth and induces apoptosis in human liver cancer cells. Taraxasterol enhances Hint1 expression by promoting demethylation in Hint1 promoter. Taraxasterol increases Hint1 levels to regulate Bax, Bcl2, and cyclinD1 expression. The effects of Taraxasterol are abrogated by Hint1 silencing in liver cancer cells. Taraxasterol inhibits the growth of subcutaneously implanted liver cancers in mice.

Cyclin D-Cdk4 is regulated by GATA-1 and required for megakaryocyte growth and polyploidization.

PubMed

Muntean, Andrew G; Pang, Liyan; Poncz, Mortimer; Dowdy, Steven F; Blobel, Gerd A; Crispino, John D

2007-06-15

Endomitosis is a unique form of cell cycle used by megakaryocytes, in which the latter stages of mitosis are bypassed so that the cell can increase its DNA content and size. Although several transcription factors, including GATA-1 and RUNX-1, have been implicated in this process, the link between transcription factors and polyploidization remains undefined. Here we show that GATA-1-deficient megakaryocytes, which display reduced size and polyploidization, express nearly 10-fold less cyclin D1 and 10-fold increased levels of p16 compared with their wild-type counterparts. We further demonstrate that cyclin D1 is a direct GATA-1 target in megakaryocytes, but not erythroid cells. Restoration of cyclin D1 expression, when accompanied by ectopic overexpression of its partner Cdk4, resulted in a dramatic increase in megakaryocyte size and DNA content. However, terminal differentiation was not rescued. Of note, polyploidization was only modestly reduced in cyclin D1-deficient mice, likely due to compensation by elevated cyclin D3 expression. Finally, consistent with an additional defect conferred by increased levels of p16, inhibition of cyclin D-Cdk4 complexes with a TAT-p16 fusion peptide significantly blocked polyploidization of wild-type megakaryocytes. Together, these data show that GATA-1 controls growth and polyploidization by regulating cyclin D-Cdk4 kinase activity.

Regulation of D-cyclin translation inhibition in myeloma cells treated with mTOR inhibitors: Rationale for combined treatment with ERK inhibitors and rapamycin

PubMed Central

Frost, Patrick; Shi, Yijiang; Hoang, Bao; Gera, Joseph; Lichtenstein, Alan

2009-01-01

We have shown that heightened AKT activity sensitized multiple myeloma (MM) cells to the anti-tumor effects of the mTOR-inhibitor, CCI-779. To test the mechanism of AKT’s regulatory role, we stably transfected U266 MM cell lines with an activated AKT allele or empty vector. The AKT-transfected cells were more sensitive to cytostasis induced in vitro by rapamycin or in vivo by its analog, CCI-779, whereas cells with quiescent AKT were resistant. The ability of mTOR inhibitors to downregulate D-cyclin expression was significantly greater in AKT-transfected MM cells, due in part, to AKT’s ability to curtail cap-independent translation and internal ribosome entry site (IRES) activity of D-cyclin transcripts. Similar AKT-dependent regulation of rapamycin responsiveness was demonstrated in a second myeloma model: the PTEN-null OPM-2 cell line transfected with wild type PTEN. As ERK/p38 activity facilitates IRES-mediated translation of some transcripts, we investigated ERK/p38 as regulators of AKT-dependent effects on rapamycin sensitivity. AKT-transfected U266 cells demonstrated significantly decreased ERK and p38 activity. However, only an ERK inhibitor prevented D-cyclin IRES activity in resistant “low AKT” myeloma cells. Furthermore, the ERK inhibitor successfully sensitized myeloma cells to rapamycin in terms of down regulated D-cyclin protein expression and G1 arrest. However, ectopic over-expression of an activated MEK gene did not increase cap-independent translation of D-cyclin in “high AKT” myeloma cells indicating that MEK/ERK activity was required but not sufficient for activation of the IRES. These data support a scenario where heightened AKT activity down-regulates D-cyclin IRES function in MM cells and ERK facilitates activity. PMID:19139116

Galangin Induces Apoptosis in MCF-7 Human Breast Cancer Cells Through Mitochondrial Pathway and Phosphatidylinositol 3-Kinase/Akt Inhibition.

PubMed

Liu, Dan; You, Pengtao; Luo, Yan; Yang, Min; Liu, Yanwen

2018-06-07

The study aimed to investigate the molecular mechanism of inhibition of proliferation and apoptosis induction by galangin against MCF-7 human breast cancer cells. Cell Counting Kit-8 assay was used to assess cell viability and flow cytometry was used to detect cell apoptosis. The expression level of apoptosis-related proteins (cleaved-caspase-9, cleaved-caspase-8, cleaved-caspase-3, Bad, cleaved-Bid, Bcl-2, Bax, p-phosphatidylinositol 3-kinase [PI3K], and p-Akt) and cell cycle-related proteins (cyclin D3, cyclin B1, cyclin-dependent kinases CDK1, CDK2, CDK4, p21, p27, p53) were evaluated by Western blotting. Galangin increased the expression of Bax and decreased the expression of Bcl-2 in a concentration-dependent manner, inhibited cell viability, and induced apoptosis. Meanwhile, the expression of cleavage of caspase-9, caspase-8, caspase-3, Bid, and Bad increased significantly while the expression of p-PI3K and p-Akt proteins decreased. In addition, the protein levels of cyclin D3, cyclin B1, CDK1, CDK2, and CDK4 were downregulated while the expression levels of p21, p27, and p53 were upregulated significantly. Galangin could suppress the viability of MCF-7 cells and induce cell apoptosis via the mitochondrial pathway and PI3K/Akt inhibition as well as cell cycle arrest. © 2018 S. Karger AG, Basel.

Involvement of cyclin D1/CDK4 and pRb mediated by PI3K/AKT pathway activation in Pb{sup 2+}-induced neuronal death in cultured hippocampal neurons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li Chenchen; Xing Tairan; Tang Mingliang

2008-06-15

Lead (Pb) is widely recognized as a neurotoxicant. One of the suggested mechanisms of lead neurotoxicity is apoptotic cell death. And the mechanism by which Pb{sup 2+} causes neuronal death is not well understood. The present study sought to examine the obligate nature of cyclin D1/cyclin-dependent kinase 4 (CDK4), phosphorylation of its substrate retinoblastoma protein (pRb) and its select upstream signal phosphoinositide 3-kinase (PI3K)/AKT pathway in the death of primary cultured rat hippocampal neurons evoked by Pb{sup 2+}. Our data showed that lead treatment of primary hippocampal cultures results in dose-dependent cell death. Inhibition of CDK4 prevented Pb{sup 2+}-induced neuronalmore » death significantly but was incomplete. In addition, we demonstrated that the levels of cyclin D1 and pRb/p107 were increased during Pb{sup 2+} treatment. These elevated expression persisted up to 48 h, returning to control levels after 72 h. We also presented pharmacological and morphological evidences that cyclin D1/CDK4 and pRb/p107 were required for such kind of neuronal death. Addition of the PI3K inhibitor LY294002 (30 {mu}M) or wortmannin (100 nM) significantly rescued the cultured hippocampal neurons from death caused by Pb{sup 2+}. And that Pb{sup 2+}-elicited phospho-AKT (Ser473) participated in the induction of cyclin D1 and partial pRb/p107 expression. These results provide evidences that cell cycle elements play a required role in the death of neurons evoked by Pb{sup 2+} and suggest that certain signaling elements upstream of cyclin D1/CDK4 are modified and/or required for this form of neuronal death.« less

Redox regulation of cardiomyocyte cell cycling via an ERK1/2 and c-Myc-dependent activation of cyclin D2 transcription

PubMed Central

Murray, Thomas V.A.; Smyrnias, Ioannis; Schnelle, Moritz; Mistry, Rajesh K.; Zhang, Min; Beretta, Matteo; Martin, Daniel; Anilkumar, Narayana; de Silva, Shana M.; Shah, Ajay M.; Brewer, Alison C.

2015-01-01

Adult mammalian cardiomyocytes have a very limited capacity to proliferate, and consequently the loss of cells after cardiac stress promotes heart failure. Recent evidence suggests that administration of hydrogen peroxide (H2O2), can regulate redox-dependent signalling pathway(s) to promote cardiomyocyte proliferation in vitro, but the potential relevance of such a pathway in vivo has not been tested. We have generated a transgenic (Tg) mouse model in which the H2O2-generating enzyme, NADPH oxidase 4 (Nox4), is overexpressed within the postnatal cardiomyocytes, and observed that the hearts of 1–3 week old Tg mice pups are larger in comparison to wild type (Wt) littermate controls. We demonstrate that the cardiomyocytes of Tg mouse pups have increased cell cycling capacity in vivo as determined by incorporation of 5-bromo-2′-deoxyuridine. Further, microarray analyses of the transcriptome of these Tg mouse hearts suggested that the expression of cyclin D2 is significantly increased. We investigated the molecular mechanisms which underlie this more proliferative phenotype in isolated neonatal rat cardiomyocytes (NRCs) in vitro, and demonstrate that Nox4 overexpression mediates an H2O2-dependent activation of the ERK1/2 signalling pathway, which in turn phosphorylates and activates the transcription factor c-myc. This results in a significant increase in cyclin D2 expression, which we show to be mediated, at least in part, by cis-acting c-myc binding sites within the proximal cyclin D2 promoter. Overexpression of Nox4 in NRCs results in an increase in their proliferative capacity that is ablated by the silencing of cyclin D2. We further demonstrate activation of the ERK1/2 signalling pathway, increased phosphorylation of c-myc and significantly increased expression of cyclin D2 protein in the Nox4 Tg hearts. We suggest that this pathway acts to maintain the proliferative capacity of cardiomyocytes in Nox4 Tg pups in vivo and so delays their exit from the cell cycle after birth. PMID:25450615

Alternative splicing variants of human Fbx4 disturb cyclin D1 proteolysis in human cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chu, Xiufeng; Zhang, Ting; Wang, Jie

2014-04-25

Highlights: • The expression of Fbx4 was significantly lower in HCC tissues. • Novel splicing variants of Fbx4 were identified. • These novel variants are much more abundant in human cancer tissues and cells. • The novel Fbx4 isoforms could promote cell proliferation and migration in vitro. • These isoforms showed less capability for cyclin D1 binding and degradation. - Abstract: Fbx4 is a specific substrate recognition component of SCF ubiquitin ligases that catalyzes the ubiquitination and subsequent degradation of cyclin D1 and Trx1. Two isoforms of human Fbx4 protein, the full length Fbx4α and the C-terminal truncated Fbx4β havemore » been identified, but their functions remain elusive. In this study, we demonstrated that the mRNA level of Fbx4 was significantly lower in hepatocellular carcinoma tissues than that in the corresponding non-tumor tissues. More importantly, we identified three novel splicing variants of Fbx4: Fbx4γ (missing 168–245nt of exon1), Fbx4δ (missing exon6) and a N-terminal reading frame shift variant (missing exon2). Using cloning sequencing and RT-PCR, we demonstrated these novel splice variants are much more abundant in human cancer tissues and cell lines than that in normal tissues. When expressed in Sk-Hep1 and NIH3T3 cell lines, Fbx4β, Fbx4γ and Fbx4δ could promote cell proliferation and migration in vitro. Concordantly, these isoforms could disrupt cyclin D1 degradation and therefore increase cyclin D1 expression. Moreover, unlike the full-length isoform Fbx4α that mainly exists in cytoplasm, Fbx4β, Fbx4γ, and Fbx4δ locate in both cytoplasm and nucleus. Since cyclin D1 degradation takes place in cytoplasm, the nuclear distribution of these Fbx4 isoforms may not be involved in the down-regulation of cytoplasmic cyclin D1. These results define the impact of alternative splicing on Fbx4 function, and suggest that the attenuated cyclin D1 degradation by these novel Fbx4 isoforms provides a new insight for aberrant cyclin D1 expression in human cancers.« less

Cyclin D–Cdk4 is regulated by GATA-1 and required for megakaryocyte growth and polyploidization

PubMed Central

Muntean, Andrew G.; Pang, Liyan; Poncz, Mortimer; Dowdy, Steven F.; Blobel, Gerd A.

2007-01-01

Endomitosis is a unique form of cell cycle used by megakaryocytes, in which the latter stages of mitosis are bypassed so that the cell can increase its DNA content and size. Although several transcription factors, including GATA-1 and RUNX-1, have been implicated in this process, the link between transcription factors and polyploidization remains undefined. Here we show that GATA-1–deficient megakaryocytes, which display reduced size and polyploidization, express nearly 10-fold less cyclin D1 and 10-fold increased levels of p16 compared with their wild-type counterparts. We further demonstrate that cyclin D1 is a direct GATA-1 target in megakaryocytes, but not erythroid cells. Restoration of cyclin D1 expression, when accompanied by ectopic overexpression of its partner Cdk4, resulted in a dramatic increase in megakaryocyte size and DNA content. However, terminal differentiation was not rescued. Of note, polyploidization was only modestly reduced in cyclin D1–deficient mice, likely due to compensation by elevated cyclin D3 expression. Finally, consistent with an additional defect conferred by increased levels of p16, inhibition of cyclin D-Cdk4 complexes with a TAT-p16 fusion peptide significantly blocked polyploidization of wild-type megakaryocytes. Together, these data show that GATA-1 controls growth and polyploidization by regulating cyclin D-Cdk4 kinase activity. PMID:17317855

CB2 Cannabinoid Receptor Targets Mitogenic Gi Protein–Cyclin D1 Axis in Osteoblasts

PubMed Central

Ofek, Orr; Attar-Namdar, Malka; Kram, Vardit; Dvir-Ginzberg, Mona; Mechoulam, Raphael; Zimmer, Andreas; Frenkel, Baruch; Shohami, Esther; Bab, Itai

2011-01-01

CB2 is a Gi protein–coupled receptor activated by endo- and phytocannabinoids, thus inhibiting stimulated adenylyl cyclase activity. CB2 is expressed in bone cells and Cb2 null mice show a marked age-related bone loss. CB2-specific agonists both attenuate and rescue ovariectomy-induced bone loss. Activation of CB2 stimulates osteoblast proliferation and bone marrow derived colony-forming units osteoblastic. Here we show that selective and nonselective CB2 agonists are mitogenic in MC3T3 E1 and newborn mouse calvarial osteoblastic cultures. The CB2 mitogenic signaling depends critically on the stimulation of Erk1/2 phosphorylation and de novo synthesis of MAP kinase–activated protein kinase 2 (Mapkapk2) mRNA and protein. Further downstream, CB2 activation enhances CREB transcriptional activity and cyclin D1 mRNA expression. The CB2-induced stimulation of CREB and cyclin D1 is inhibitable by pertussis toxin, the MEK-Erk1/2 inhibitors PD098059 and U0126, and Mapkapk2 siRNA. These data demonstrate that in osteoblasts CB2 targets a Gi protein–cyclin D1 mitogenic axis. Erk1/2 phosphorylation and Mapkapk2 protein synthesis are critical intermediates in this axis. © 2011 American Society for Bone and Mineral Research. PMID:20803555

Overexpression of microRNA-95-3p suppresses brain metastasis of lung adenocarcinoma through downregulation of cyclin D1.

PubMed

Hwang, Su Jin; Lee, Hye Won; Kim, Hye Ree; Song, Hye Jin; Lee, Dong Heon; Lee, Hong; Shin, Chang Hoon; Joung, Je-Gun; Kim, Duk-Hwan; Joo, Kyeung Min; Kim, Hyeon Ho

2015-08-21

Despite great efforts to improve survival rates, the prognosis of lung cancer patients is still very poor, mainly due to high invasiveness. We developed brain metastatic PC14PE6/LvBr4 cells through intracardiac injection of lung adenocarcinoma PC14PE6 cells. Western blot and RT-qPCR analyses revealed that PC14PE6/LvBr4 cells had mesenchymal characteristics and higher invasiveness than PC14PE6 cells. We found that cyclin D1 was upregulated, miR-95-3p was inversely downregulated, and pri-miR-95 and its host gene, ABLIM2, were consistently decreased in PC14PE6/LvBr4 cells. MiR-95-3p suppressed cyclin D1 expression through direct binding to the 3' UTR of cyclin D1 mRNA and suppressed invasiveness, proliferation, and clonogenicity of PC14PE6/LvBr4 cells. Ectopic cyclin D1 reversed miR-95-3p-mediated inhibition of invasiveness and clonogenicity, demonstrating cyclin D1 downregulation is involved in function of miR-95-3p. Using bioluminescence imaging, we found that miR-95-3p suppressed orthotopic tumorigenicity and brain metastasis in vivo and increased overall survival and brain metastasis-free survival. Consistent with in vitro metastatic cells, the levels of miR-95-3p, pri-miR-95, and ABLIM2 mRNA were decreased in brain metastatic tissues compared with lung cancer tissues and higher cyclin D1 expression was involved in poor prognosis. Taken together, our results demonstrate that miR-95-3p is a potential therapeutic target for brain metastasis of lung adenocarcinoma cells.

Cyclin D1 negatively regulates the expression of differentiation genes in HT-29 M6 mucus-secreting colon cancer cells.

PubMed

Mayo, Clara; Mayol, Xavier

2009-08-28

HT-29 M6 colon cancer cells differentiate to a mucus-secreting phenotype in culture. We found that the pattern of cyclin D1 expression in HT-29 M6 cells did not correlate with instances of cell proliferation but was specifically induced during a dedifferentiation process following disaggregation of epithelial cell layers, even under conditions that did not allow cell cycle reentrance. Interestingly, ectopic expression of cyclin D1 in differentiated cells led to the inhibition of the transcriptional activity of differentiation gene promoters, such as the mucin MUC1. We thus propose that the overexpression of cyclin D1 found in colon cancer favours tumour dedifferentiation as one mechanism of tumour progression.

HTLV-1 basic leucine zipper factor downregulates cyclin D1 expression via interactions with NF-κB.

PubMed

Ma, Yunyun; Zhang, Bo; Wang, Dong; Qian, Lili; Song, Xianmei; Wang, Xueyin; Yang, Chaokuan; Zhao, Guoqiang

2017-03-01

Human T cell leukemia virus type 1 (HTLV-1) is an oncogenic retrovirus. It can cause adult T cell leukemia (ATL) and other diseases. The HTLV-1 basic leucine zipper (bZIP) factor (HBZ), which is encoded by the minus-strand of the provirus, is expressed in all cases of ATL and involved in T cell proliferation. However, the exact mechanism underlying its growth-promoting activity is poorly understood. Herein, we demonstrated that HBZ suppressed cyclin D1 expression by inhibiting the nuclear factor (NF)-κB signaling pathway. Among the potential mechanisms of cyclin D1 inhibition mediated by HBZ, we found that HBZ suppressed cyclin D1 promoter activity. Luciferase assay analysis revealed that HBZ repressed cyclin D1 promoter activity by suppressing NF-κB‑driven transcription mediated by the p65 subunit. Using an immunoprecipitation assay, we found that HBZ could bind to p65, but not p50. Finally, we showed that HBZ selectively interacted with p65 via its AD+bZIP domains. By suppressing cyclin D1 expression, HBZ can alter cell cycle progression of HTLV-1-infected cells, which may be critical for oncogenesis.

Implications of caspase-dependent proteolytic cleavage of cyclin A1 in DNA damage-induced cell death

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woo, Sang Hyeok; Seo, Sung-Keum; An, Sungkwan

Highlights: • Caspase-1 mediates doxorubicin-induced downregulation of cyclin A1. • Active caspase-1 effectively cleaved cyclin A1 at D165. • Cyclin A1 expression is involved in DNA damage-induced cell death. - Abstract: Cyclin A1 is an A-type cyclin that directly binds to CDK2 to regulate cell-cycle progression. In the present study, we found that doxorubicin decreased the expression of cyclin A1 at the protein level in A549 lung cancer cells, while markedly downregulating its mRNA levels. Interestingly, doxorubicin upregulated caspase-1 in a concentration-dependent manner, and z-YAVD-fmk, a specific inhibitor of caspase-1, reversed the doxorubicin-induced decrease in cyclin A1 in A549 lungmore » cancer and MCF7 breast cancer cells. Active caspase-1 effectively cleaved cyclin A1 at D165 into two fragments, which in vitro cleavage assays showed were further cleaved by caspase-3. Finally, we found that overexpression of cyclin A1 significantly reduced the cytotoxicity of doxorubicin, and knockdown of cyclin A1 by RNA interference enhanced the sensitivity of cells to ionizing radiation. Our data suggest a new mechanism for the downregulation of cyclin A1 by DNA-damaging stimuli that could be intimately involved in the cell death induced by DNA damage-inducing stimuli, including doxorubicin and ionizing radiation.« less

DDAH1 deficiency attenuates endothelial cell cycle progression and angiogenesis.

PubMed

Zhang, Ping; Xu, Xin; Hu, Xinli; Wang, Huan; Fassett, John; Huo, Yuqing; Chen, Yingjie; Bache, Robert J

2013-01-01

Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide (NO) synthase (NOS). ADMA is eliminated largely by the action of dimethylarginine dimethylaminohydrolase1 (DDAH1). Decreased DDAH activity is found in several pathological conditions and is associated with increased risk of vascular disease. Overexpression of DDAH1 has been shown to augment endothelial proliferation and angiogenesis. To better understand the mechanism by which DDAH1 influences endothelial proliferation, this study examined the effect of DDAH1 deficiency on cell cycle progression and the expression of some cell cycle master regulatory proteins. DDAH1 KO decreased in vivo Matrigel angiogenesis and depressed endothelial repair in a mouse model of carotid artery wire injury. DDAH1 deficiency decreased VEGF expression in HUVEC and increased NF1 expression in both HUVEC and DDAH1 KO mice. The expression of active Ras could overcome the decreased VEGF expression caused by the DDAH1 depletion. The addition of VEGF and knockdown NF1 could both restore proliferation in cells with DDAH1 depletion. Flow cytometry analysis revealed that DDAH1 sRNAi knockdown in HUVEC caused G1 and G2/M arrest that was associated with decreased expression of CDC2, CDC25C, cyclin D1 and cyclin E. MEF cells from DDAH1 KO mice also demonstrated G2/M arrest that was associated with decreased cyclin D1 expression and Akt activity. Our findings indicate that DDAH1 exerts effects on cyclin D1 and cyclin E expression through multiple mechanisms, including VEGF, the NO/cGMP/PKG pathway, the Ras/PI3K/Akt pathway, and NF1 expression. Loss of DDAH1 effects on these pathways results in impaired endothelial cell proliferation and decreased angiogenesis. The findings provide background information that may be useful in the development of therapeutic strategies to manipulate DDAH1 expression in cardiovascular diseases or tumor angiogenesis.

DDAH1 Deficiency Attenuates Endothelial Cell Cycle Progression and Angiogenesis

PubMed Central

Zhang, Ping; Xu, Xin; Hu, Xinli; Wang, Huan; Fassett, John; Huo, Yuqing; Chen, Yingjie; Bache, Robert J.

2013-01-01

Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide (NO) synthase (NOS). ADMA is eliminated largely by the action of dimethylarginine dimethylaminohydrolase1 (DDAH1). Decreased DDAH activity is found in several pathological conditions and is associated with increased risk of vascular disease. Overexpression of DDAH1 has been shown to augment endothelial proliferation and angiogenesis. To better understand the mechanism by which DDAH1 influences endothelial proliferation, this study examined the effect of DDAH1 deficiency on cell cycle progression and the expression of some cell cycle master regulatory proteins. DDAH1 KO decreased in vivo Matrigel angiogenesis and depressed endothelial repair in a mouse model of carotid artery wire injury. DDAH1 deficiency decreased VEGF expression in HUVEC and increased NF1 expression in both HUVEC and DDAH1 KO mice. The expression of active Ras could overcome the decreased VEGF expression caused by the DDAH1 depletion. The addition of VEGF and knockdown NF1 could both restore proliferation in cells with DDAH1 depletion. Flow cytometry analysis revealed that DDAH1 sRNAi knockdown in HUVEC caused G1 and G2/M arrest that was associated with decreased expression of CDC2, CDC25C, cyclin D1 and cyclin E. MEF cells from DDAH1 KO mice also demonstrated G2/M arrest that was associated with decreased cyclin D1 expression and Akt activity. Our findings indicate that DDAH1 exerts effects on cyclin D1 and cyclin E expression through multiple mechanisms, including VEGF, the NO/cGMP/PKG pathway, the Ras/PI3K/Akt pathway, and NF1 expression. Loss of DDAH1 effects on these pathways results in impaired endothelial cell proliferation and decreased angiogenesis. The findings provide background information that may be useful in the development of therapeutic strategies to manipulate DDAH1 expression in cardiovascular diseases or tumor angiogenesis. PMID:24260221

Essential roles of PI-3K/Akt/IKKbeta/NFkappaB pathway in cyclin D1 induction by arsenite in JB6 Cl41 cells.

PubMed

Ouyang, Weiming; Li, Jingxia; Ma, Qian; Huang, Chuanshu

2006-04-01

Skin is a major target of carcinogenic trivalent arsenic (arsenite, As3+). It has been thought that cell proliferation is one of the central events involved in the carcinogenic effect of arsenite. Cyclin D1, a nuclear protein playing a pivotal role in cell proliferation and cell cycle transition from G1 to S phases, has been reported to be induced in human fibroblast by arsenite via uncertain molecular mechanisms. In the present study, the potential roles of PI-3K/Akt/IKKbeta/NFkappaB signal pathway in cyclin D1 induction by arsenite were addressed in mouse epidermal Cl41 cells. We found that exposure of Cl41 cells to arsenite was able to induce cell proliferation, activate PI-3K-->Akt/p70(S6k) signal pathway and increase cyclin D1 expression at both transcription and protein levels. Pre-treatment of Cl41 cells with PI-3K inhibitor, wortmannin, significantly inhibited the phosphorylation of Akt and p70(S6k) and thereby dramatically impaired the cyclin D1 induction by arsenite, implicating the importance of the PI-3K signal pathway in the cyclin D1 induction by arsenite. Furthermore, inhibition of PI-3K/Akt by overexpression of Deltap85 or DN-Akt blocked arsenite-induced IKK phosphorylation, IkappaBalpha degradation and cyclin D1 expression, indicating that IKK/NFkappaB is the downstream transducer of arsenite-triggered PI-3K/Akt cascade. Moreover, inhibition of IKKbeta/NFkappaB signal pathway by overexpression of its dominant negative mutant, IKKbeta-KM, also significantly blocked arsenite-induced cyclin D1 expression. Overall, arsenite exposure triggered PI-3K/Akt/IKKbeta/NFkappaB signal cascade which in turn plays essential roles in inducing cyclin D1 expression.

Alteronol induces cell cycle arrest and apoptosis via increased reactive oxygen species production in human breast cancer T47D cells.

PubMed

Ren, Boxue; Li, Defang; Si, Lingling; Ding, Yangfang; Han, Jichun; Chen, Xiaoyu; Zheng, Qiusheng

2018-04-01

Emerging evidence showed that alteronol has a potential antitumour effect in several tumour cells. However, the antitumour effect of alteronol on breast cancer has not been reported. This study investigated the mechanisms of alteronol-induced cell proliferation inhibition in human breast cancer T47D cells. After treatment with alteronol, T47D cell proliferation was examined by MTT assay. The cell cycle distribution, cell apoptosis, reactive oxygen species level and mitochondrial membrane potential were evaluated via flow cytometry. Next, the protein levels of cyclin B1, cdc2, p21, p-cyclin B1, p-cdc2, p53, Bax, Bcl-2 and cytochrome c were analysed using Western blot analysis. Meanwhile, the mRNA levels of cyclin B1, cdc2, p21 and p53 were examined by qRT-PCR. Our data showed that alteronol inhibited the proliferation of T47D cells via inducing G2-phase arrest and cell apoptosis. Compared with control group, alteronol significantly increased ROS level and triggered mitochondrial dysfunction in alteronol-treated T47D cells. Further studies showed that the mRNA and protein levels of cdc2 and cyclin B1 were downregulated, while the mRNA and protein levels of p21, p53, p-cyclin B1, p-cdc2 and cytochrome c were upregulated. In addition, the expression level of Bax was increased, and the expression level of Bcl-2 was decreased. Alteronol induced T47D cell cycle arrest and cell apoptosis through increasing ROS production and triggering mitochondrial dysfunction, and subsequently inhibiting T47D cell proliferation. © 2018 Royal Pharmaceutical Society.

Tea polyphenols can restrict benzo[a]pyrene-induced lung carcinogenesis by altered expression of p53-associated genes and H-ras, c-myc and cyclin D1.

PubMed

Manna, Sugata; Mukherjee, Sudeshna; Roy, Anup; Das, Sukta; Panda, Chinmay Kr

2009-05-01

The modulatory influence of tea polyphenols (epigallocatechin gallate, epicatechin gallate and theaflavin) on benzo[a]pyrene (B[a]P)-induced lung carcinogenesis in mice was analyzed using histopathological and molecular parameters. Progression of lung lesions was restricted at the hyperplastic stage by tea polyphenols. A significant reduction in cellular proliferative index and an increase in apoptotic index were noted in the restricted lung lesions. High expression of H-ras, c-myc, cyclin D1 and p53 genes was seen at the inflammatory stage (9th week) and in subsequent premalignant lesions, but down-regulation of H-ras at the hyperplastic stage (17th week). Expression of bcl-2 was high in hyperplastic lesions, whereas the expression of mdm2 and bcl-xl increased only at the moderately dysplastic stage (36th week). The tea polyphenols inhibited inflammatory response in the lung lesions on the 9th week, when decreased expression of H-ras and c-myc and increased expression of bax were noted. Prolonged treatment (>9th week) with tea polyphenols resulted in changes in the expression of some additional genes, such as reduced expression of cyclin D1 (from the 17th week), bcl-2 (from the 26th week; mild dysplasia) and p21 (on the 36th week), and high expression of p53 (from the 17th week) and p27 (on the 36th week). These observations indicate that the tea polyphenols can restrict B[a]P-induced lung carcinogenesis by differential modulation of the expression of p53 and its associated genes such as bax, bcl-2, mdm2, p21 and p27, along with H-ras, c-myc and cyclin D1, at different time points.

Cyclin D1 in ASM Cells from Asthmatics Is Insensitive to Corticosteroid Inhibition.

PubMed

Allen, Jodi C; Seidel, Petra; Schlosser, Tobias; Ramsay, Emma E; Ge, Qi; Ammit, Alaina J

2012-01-01

Hyperplasia of airway smooth muscle (ASM) is a feature of the remodelled airway in asthmatics. We examined the antiproliferative effectiveness of the corticosteroid dexamethasone on expression of the key regulator of G(1) cell cycle progression-cyclin D1-in ASM cells from nonasthmatics and asthmatics stimulated with the mitogen platelet-derived growth factor BB. While cyclin D1 mRNA and protein expression were repressed in cells from nonasthmatics in contrast, cyclin D1 expression in asthmatics was resistant to inhibition by dexamethasone. This was independent of a repressive effect on glucocorticoid receptor translocation. Our results corroborate evidence demonstrating that corticosteroids inhibit mitogen-induced proliferation only in ASM cells from subjects without asthma and suggest that there are corticosteroid-insensitive proliferative pathways in asthmatics.

Deficiency of the NR4A Orphan Nuclear Receptor NOR1 attenuates Neointima Formation Following Vascular Injury

PubMed Central

Nomiyama, Takashi; Zhao, Yue; Gizard, Florence; Findeisen, Hannes M.; Heywood, Elizabeth B.; Jones, Karrie L.; Conneely, Orla M.; Bruemmer, Dennis

2009-01-01

Background The neuron-derived orphan receptor-1 (NOR1) belongs to the evolutionary highly conserved and most ancient NR4A subfamily of the nuclear hormone receptor superfamily. Members of this subfamily function as early response genes regulating key cellular processes including proliferation, differentiation, and survival. Although NOR1 has previously been demonstrated to be required for smooth muscle cell (SMC) proliferation in vitro, the role of this nuclear receptor for the proliferative response underlying neointima formation and target genes trans-activated by NOR1 remain to be defined. Methods and Results Using a model of guide wire-induced arterial injury, we demonstrate decreased neointima formation in NOR1-/- mice compared to wildtype mice. In vitro, NOR1-deficient SMC exhibit decreased proliferation due to a G1→S phase arrest of the cell cycle and increased apoptosis in response to serum deprivation. NOR1-deficiency alters phosphorylation of the retinoblastoma protein by preventing mitogen-induced cyclin D1 and D2 expression. Conversely, overexpression of NOR1 induces cyclin D1 expression and the transcriptional activity of the cyclin D1 promoter in transient reporter assays. Gel shift and chromatin immunoprecipitation assays identified a putative response element for NR4A receptors in the cyclin D1 promoter, to which NOR1 is recruited in response to mitogenic stimulation. Finally, we provide evidence that these observations are applicable in vivo by demonstrating decreased cyclin D1 expression during neointima formation in NOR1-deficient mice. Conclusions These experiments characterize cyclin D1 as a NOR1-regulated target gene in SMC and demonstrate that NOR1 deficiency decreases neointima formation in response to vascular injury. PMID:19153266

ClC-3 Chloride Channel Proteins Regulate the Cell Cycle by Up-regulating cyclin D1-CDK4/6 through Suppressing p21/p27 Expression in Nasopharyngeal Carcinoma Cells

PubMed Central

Ye, Dong; Luo, Hai; Lai, Zhouyi; Zou, Lili; Zhu, Linyan; Mao, Jianwen; Jacob, Tim; Ye, Wencai; Wang, Liwei; Chen, Lixin

2016-01-01

It was shown in this study that knockdown of ClC-3 expression by ClC-3 siRNA prevented the activation of hypotonicity-induced chloride currents, and arrested cells at the G0/G1 phase in nasopharyngeal carcinoma CNE-2Z cells. Reconstitution of ClC-3 expression with ClC-3 expression plasmids could rescue the cells from the cell cycle arrest caused by ClC-3 siRNA treatments. Transfection of cells with ClC-3 siRNA decreased the expression of cyclin D1, cyclin dependent kinase 4 and 6, and increased the expression of cyclin dependent kinase inhibitors (CDKIs), p21 and p27. Pretreatments of cells with p21 and p27 siRNAs depleted the inhibitory effects of ClC-3 siRNA on the expression of CDK4 and CDK6, but not on that of cyclin D1, indicating the requirement of p21 and p27 for the inhibitory effects of ClC-3 siRNA on CDK4 and CDK6 expression. ClC-3 siRNA inhibited cells to progress from the G1 phase to the S phase, but pretreatments of cells with p21 and p27 siRNAs abolished the inhibitory effects of ClC-3 siRNA on the cell cycle progress. Our data suggest that ClC-3 may regulate cell cycle transition between G0/G1 and S phases by up-regulation of the expression of CDK4 and CDK6 through suppression of p21 and p27 expression. PMID:27451945

Knocking down cyclin D1b inhibits breast cancer cell growth and suppresses tumor development in a breast cancer model.

PubMed

Wei, Min; Zhu, Li; Li, Yafen; Chen, Weiguo; Han, Baosan; Wang, Zhiwei; He, Jianrong; Yao, Hongliang; Yang, Zhongyin; Zhang, Qing; Liu, Bingya; Gu, Qinlong; Zhu, Zhenggang; Shen, Kunwei

2011-08-01

Cyclin D1 is aberrantly expressed in many types of cancers, including breast cancer. High levels of cyclin D1b, the truncated isoform of cyclin D1, have been reported to be associated with a poor prognosis for breast cancer patients. In the present study, we used siRNA to target cyclin D1b overexpression and assessed its ability to suppress breast cancer growth in nude mice. Cyclin D1b siRNA effectively inhibited overexpression of cyclin D1b. Depletion of cyclin D1b promoted apoptosis of cyclin D1b-overexpressing cells and blocked their proliferation and transformation phenotypes. Notably, cyclin D1b overexpression is correlated with triple-negative basal-like breast cancers, which lack specific therapeutic targets. Administration of cyclin D1b siRNA inhibited breast tumor growth in nude mice and cyclin D1b siRNA synergistically enhanced the cell killing effects of doxorubicin in cell culture, with this combination significantly suppressing tumor growth in the mouse model. In conclusion, the results indicate that cyclin D1b, which is overexpressed in breast cancer, may serve as a novel and effective therapeutic target. More importantly, the present study clearly demonstrated a very promising therapeutic potential for cyclin D1b siRNA in the treatment of cyclin D1b-overexpressing breast cancers, including the very malignant triple-negative breast cancers. © 2011 Japanese Cancer Association.

Cyclin D2 is a critical mediator of exercise-induced cardiac hypertrophy.

PubMed

Luckey, Stephen W; Haines, Chris D; Konhilas, John P; Luczak, Elizabeth D; Messmer-Kratzsch, Antke; Leinwand, Leslie A

2017-12-01

A number of signaling pathways underlying pathological cardiac hypertrophy have been identified. However, few studies have probed the functional significance of these signaling pathways in the context of exercise or physiological pathways. Exercise studies were performed on females from six different genetic mouse models that have been shown to exhibit alterations in pathological cardiac adaptation and hypertrophy. These include mice expressing constitutively active glycogen synthase kinase-3β (GSK-3βS9A), an inhibitor of CaMK II (AC3-I), both GSK-3βS9A and AC3-I (GSK-3βS9A/AC3-I), constitutively active Akt (myrAkt), mice deficient in MAPK/ERK kinase kinase-1 (MEKK1 -/- ), and mice deficient in cyclin D2 (cyclin D2 -/- ). Voluntary wheel running performance was similar to NTG littermates for five of the mouse lines. Exercise induced significant cardiac growth in all mouse models except the cyclin D2 -/- mice. Cardiac function was not impacted in the cyclin D2 -/- mice and studies using a phospho-antibody array identified six proteins with increased phosphorylation (greater than 150%) and nine proteins with decreased phosphorylation (greater than 33% decrease) in the hearts of exercised cyclin D2 -/- mice compared to exercised NTG littermate controls. Our results demonstrate that unlike the other hypertrophic signaling molecules tested here, cyclin D2 is an important regulator of both pathologic and physiological hypertrophy. Impact statement This research is relevant as the hypertrophic signaling pathways tested here have only been characterized for their role in pathological hypertrophy, and not in the context of exercise or physiological hypertrophy. By using the same transgenic mouse lines utilized in previous studies, our findings provide a novel and important understanding for the role of these signaling pathways in physiological hypertrophy. We found that alterations in the signaling pathways tested here had no impact on exercise performance. Exercise induced cardiac growth in all of the transgenic mice except for the mice deficient in cyclin D2. In the cyclin D2 null mice, cardiac function was not impacted even though the hypertrophic response was blunted and a number of signaling pathways are differentially regulated by exercise. These data provide the field with an understanding that cyclin D2 is a key mediator of physiological hypertrophy.

Accelerated Stem Growth Rates and Improved Fiber Properties of Loblolly Pine: Functional Analysis Of CyclinD from Pinus taeda

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dr. John Cairney, School of Biology and Institute of Paper Science and Technology @ Georgia Tech, Georgia Institute of Technology; Dr. Gary Peter, University of Florida; Dr. Ulrika Egertsdotter, Dept. of Forestry, Virgina Tech

A sustained supply of low-cost, high quality raw materials is essential for the future success of the U.S. forest products industry. To maximize stem (trunk) growth, a fundamental understanding of the molecular mechanisms that regulate cell divisions within the cambial meristem is essential. We hypothesize that auxin levels within the cambial meristem regulate cyclin gene expression and this in turn controls cell cycle progression as occurs in all eukaryotic cells. Work with model plant species has shown that ectopic overexpression of cyclins promotes cell division thereby increasing root growth > five times. We intended to test whether ectopic overexpression ofmore » cambial cyclins in the cambial zone of loblolly pine also promotes cell division rates that enhance stem growth rates. Results generated in model annual angiosperm systems cannot be reliably extrapolated to perennial gymnosperms, thus while the generation and development of transgenic pine is time consuming, this is the necessary approach for meaningful data. We succeeded in isolating a cyclin D gene and Clustal analysis to the Arabidopsis cyclin D gene family indicates that it is more closely related to cyclin D2 than D1 or D3 Using this gene as a probe we observed a small stimulation of cyclin D expression in somatic embryo culture upon addition of auxin. We hypothesized that trees with more cells in the vascular cambial and expansion zones will have higher cyclin mRNA levels. We demonstrated that in trees under compressive stress where the rates of cambial divisions are increased on the underside of the stem relative to the top or opposite side, there was a 20 fold increase in the level of PtcyclinD1 mRNA on the compressed side of the stem relative to the opposite. This suggests that higher secondary growth rates correlate with PtcyclinD1 expression. We showed that larger diameter trees show more growth during each year and that the increased growth in loblolly pine trees correlates with more cell divisions in the cambial meristem as expected. We isolated a promoter from a cambial specific gene and commenced development of transformation protocols for loblolly pine. Since our results show that cyclin D expression correlates with increased growth we continued with experiments to demonstrate the effect of cyclin overexpression upon tree growth. Vectors which constitutively express the cyclin D cDNA were constructed and transformed into a transgenic pine system through the collaboration with Forest Research, New Zealand. The transformation system for Pinus radiata is well established and we hoped to gain phenotypic information in a closely related pine, rather than await development of a robust loblolly pine transformation method. Transformation experiments were conducted by a biolistic method developed at Forest Research, NZ. A total of 78 transgenic embryogenic lines were generated and bulked up with a good representation of transgenic lines per construct. Transformed calli were originally identified by resistance to the antibiotic Geneticin contained in the medium. The transgenic nature of the selected lines was subsequently confirmed using histochemical GUS staining. To date, 10 out of 13 selected transgenic lines have produced embryos and we are currently harvesting the first transgenic plantlets. At present time 22 of those plantlets have been moved to GMO facilities. We will soon develop a strategy for assessing potential phenotypic differences between the transclones and non-transformed controls. Transgenic plants are being grown to a stage (approx. 1 year) when meaningful phenotypic evaluation can be conducted. The recent availability of 10,000 element loblolly pine cDNA microarray will permit the evaluation of cyclinD overexpression upon gene expression in transgenic Pinus.« less

The effect of the ginger on the apoptosis of hippochampal cells according to the expression of BAX and Cyclin D1 genes and histological characteristics of brain in streptozotocin male diabetic rats.

PubMed

Molahosseini, A; Taghavi, M M; Taghipour, Z; Shabanizadeh, A; Fatehi, F; Kazemi Arababadi, M; Eftekhar Vaghefe, S H

2016-10-31

Diabetes is the most common endocrine disorder in humans with multiple complications including nervous system damages. The aim of the present study was to determine the effect of ginger extract on apoptosis of the neurons of hippocampus, via evaluation of BAX and Cyclin D1 and also histological analysis, in male diabetic rats. In this experimental study, 60 Wistar rats (220 ± 30gr) were conducted in 5 groups as follow: diabetic group treated with saline (group 1), normal group treated with saline (group 2), diabetic group treated with ginger (group 3), diabetic group treated with ginger-insulin (group 4), diabetic group treated with insulin (group 5). STZ (60 mg/kg) was intraperitoneally used to induce the diabetes. Expression levels of BAX and Cyclin D1 were examined using Real-Time PCR technique and the normality of neurons was evaluated using H&E staining method. The results showed that blood glucose level significantly decreased in group 4 when compared to group 1. In molecular analysis, there was no significant difference between groups regarding the expression of BAX gens, while, the expression of Cyclin D1 were significantly decreased in group 4 compared with group 1. Histological analysis revealed that pathological symptoms were lower in group 4 than the other diabetic groups. The results of present study showed that the ginger in addition to lowering blood sugar level, changes the expression of Cyclin D1 gene and histological characteristics in a positive manner. This means that the ginger may protects neurons of the hippocampus from apoptosis in diabetic patients.

Expression of Cyclin d1 protein and CCND1 та PNKP genes in peripheral blood mononuclear cells in clean up worker of Chornobyl accident with different state of immune system.

PubMed

Bazyka, D A; Kubashko, A V; Ilyenko, I M; Belyaev, O A; Pleskach, O J

2015-12-01

to investigate the Cyclin D1+ cells levels changes, associated CCND1 and PNKP genes in peripheral blood mononuclear cells in clean up workers of Chornobyl accident with different state of immune system in depends on the dose irradiation. Relative level of Cyclin D1+cells in peripheral blood mononuclears of 39 clean up workers, men, irradiated in dose range (0,01-2,00) Gy have been analyzed. Immunological status of examinee' subjects was determined by CD3/19, CD4/8, CD3/HLA DR, СD3/16/56 testing using flow cytometry method and Ig A,M,G testing by immunoenzymatic assay in blood. CCND1 та PNKP gene expression, which associated with Cyclin D1 metabolism, was conducted using PCR real time method. The obtained results were compared in relation to data from 18 healthy men, who had no contact with ionizing radiation over then nature background. Аnalyzed data of the nuclear controller of cell cycle - Cyclin D1 protein expression changes and related CCND1 та PNKP genes in peripheral blood mononuclear cells in clean up workers Chornobyl accident with different status of immune system in remote period after exposure is represented. It is shown, that in examinees' subjects exposed in dose > 0,1 Gy percentage of Суclin D1+ cells is elevated against normal range and correlates with dose of radiation (rs = 0,417, p = 0,048). Normal range deflation of relative amount of Cyclin D1+cells connects with changes in cellular and humoral immunity. Decline of relative amount of Cyclin D1+ cells below the control level following CD3+ lymphocytes decrease and CD3 16+56+ elevation in clean up workers exposed in dose < 0,35 Gy. Increase of relative amount of Cyclin D1+ cells above the control range associates with CD3+ fall together with tendency of CD3+16+56+ lymphocytes fall that attends the IgG elevation in examinees' subjects with dose > 0,35 Gy. Percentage of Cyclin D1+ cells correlates with CD3 16+56+ (rs = 0,872, p = 0,049), CD8+ and IgG (rs = 0,683, p = 0,042; rs = 0,809, p = 0,014), CD4+ (rs = 0,602, p = 0,029), CD19+ and IgM (rs = 0,604, p = 0,017; rs = 0,538, p = 0,038) under condition of increased level CD4+, CD19+, Іreg. and IgG accordantly. Reviled decrease the CCND1 and PNKP gene expression in clean up workers exposed in dose > 0,1 Gy following appearance of correlation between (relative quantification) RQ PNKP and irradiation dose (rs = 0,638, p = 0,035) and also with RQ PNKP and percentage of Cyclin D1+ cells (rs = 0,792, p = 0,034).Concusions. Reveled changes in expression of Cyclin D1+ cells and regulation of related genes may point on possi ble radiation associated firm molecular disturbances occurred during elimination of consequences of Chornobyl accident, that could be a potential basis for cell and humoral communicative links breach in immune system result ing in elevation of stochastic effects like oncopathology in clean up workers of Chornobyl accident in remote peri od after exposure. D. A. Bazyka, A. V. Kubashko, I. M. Ilyenko, O. A. Belyaev, O. J. Pleskach.

ROS-dependent HMGA2 upregulation mediates Cd-induced proliferation in MRC-5 cells.

PubMed

Xie, Huaying; Wang, Jiayue; Jiang, Liping; Geng, Chengyan; Li, Qiujuan; Mei, Dan; Zhao, Lian; Cao, Jun

2016-08-01

Cadmium (Cd) is a heavy metal widely found in a number of environmental matrices, and the exposure to Cd is increasing nowadays. In this study, the role of high mobility group A2 (HMGA2) in Cd-induced proliferation was investigated in MRC-5 cells. Exposure to Cd (2μM) for 48h significantly enhanced the growth of MRC-5 cells, increased reactive oxygen species (ROS) production, and induced both mRNA and protein expression of HMGA2. Evidence for Cd-induced reduction of the number of G0/G1 phase cells and an increase in the number of cells in S phase and G2/M phase was sought by flow cytometric analysis. Western blot analysis showed that cyclin D1, cyclin B1, and cyclin E were upregulated in Cd-treated cells. Further study revealed that N-acetyl cysteine (NAC) markedly prevented Cd-induced proliferation of MRC-5 cells, ROS generation, and the increasing protein level of HMGA2. Silencing of HMGA2 gene by siRNA blocked Cd-induced cyclin D1, cyclin B1, and cyclin E expression and reduction of the number of G0/G1 phase cells. Combining, our data showed that Cd-induced ROS formation provoked HMGA2 upregulation, caused cell cycle changes, and led to cell proliferation. This suggests that HMGA2 might be an important biomarker in Cd-induced cell proliferation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Amplification and protein overexpression of cyclin D1: Predictor of occult nodal metastasis in early oral cancer.

PubMed

Noorlag, Rob; Boeve, Koos; Witjes, Max J H; Koole, Ronald; Peeters, Ton L M; Schuuring, Ed; Willems, Stefan M; van Es, Robert J J

2017-02-01

Accurate nodal staging is pivotal for treatment planning in early (stage I-II) oral cancer. Unfortunately, current imaging modalities lack sensitivity to detect occult nodal metastases. Chromosomal region 11q13, including genes CCND1, Fas-associated death domain (FADD), and CTTN, is often amplified in oral cancer with nodal metastases. However, evidence in predicting occult nodal metastases is limited. In 158 patients with early tongue and floor of mouth (FOM) squamous cell carcinomas, both CCND1 amplification and cyclin D1, FADD, and cortactin protein expression were correlated with occult nodal metastases. CCND1 amplification and cyclin D1 expression correlated with occult nodal metastases. Cyclin D1 expression was validated in an independent multicenter cohort, confirming the correlation with occult nodal metastases in early FOM cancers. Cyclin D1 is a predictive biomarker for occult nodal metastases in early FOM cancers. Prospective research on biopsy material should confirm these results before implementing its use in routine clinical practice. © 2016 Wiley Periodicals, Inc. Head Neck 39: 326-333, 2017. © 2016 Wiley Periodicals, Inc.

The involvement of cyclin D1 degradation through GSK3β-mediated threonine-286 phosphorylation-dependent nuclear export in anti-cancer activity of mulberry root bark extracts.

PubMed

Eo, Hyun Ji; Park, Gwang Hun; Jeong, Jin Boo

2016-02-15

Mulberry root bark was shown to induce cyclin D1 proteasomal degradation in the human colorectal cancer cells. Still, the molecular mechanisms whereby mulberry root bark induces cyclin D1 proteasomal degradation remain largely unknown. In this study, the inhibitory effect of mulberry root bark (MRB) on the proliferation of human colorectal cancer cells and the mechanism of action were examined to evaluate its anti-cancer activity. Anti-proliferative effect was determined by MTT assay. RT-PCR and Western blotting were used to assess the mRNA and protein expression of related proteins. MRB inhibited markedly the proliferation of human colorectal cancer cells (HCT116, SW480 and LoVo). In addition, the proliferation of human breast cancer cells (MDA-MB-231 and MCF-7) was suppressed by MRB treatment. However, MRB did not affect the growth of HepG-2 cells as a human hepatocellular carcinoma cell line. MRB effectively decreased cyclin D1 protein level in human colorectal cancer cells and breast cancer cells, but not in hepatocellular carcinoma cells. Contrast to protein levels, cyclin D1 mRNA level did not be changed by MRB treatment. Inhibition of proteasomal degradation by MG132 attenuated MRB-mediated cyclin D1 downregulation and the half-life of cyclin D1 was decreased in the cells treated with MRB. In addition, MRB increased phosphorylation of cyclin D1 at threonine-286 and a point mutation of threonine-286 to alanine attenuated MRB-mediated cyclin D1 degradation. Inhibition of GSK3β by LiCl suppressed cyclin D1 phosphorylation and downregulation by MRB. MRB decreased the nuclear level of cyclin D1 and the inhibition of nuclear export by LMB attenuated MRB-mediated cyclin D1 degradation. MRB has anti-cancer activity by inducing cyclin D1 proteasomal degradation through cyclin D1 nuclear export via GSK3β-dependent threonine-286 phosphorylation. These findings suggest that possibly its extract could be used for treating colorectal cancer. Copyright © 2015 Elsevier GmbH. All rights reserved.

[RNA interference of HERC4 inhibits proliferation, apoptosis and migration of cervical cancer Hela cells].

PubMed

Wei, Min; Zhang, Yan-Ling; Chen, Lan; Cai, Cui-Xia; Wang, Han-Duo

2016-02-20

To explore the effects of silencing HERC4 on the proliferation, apoptosis, and migration of cervical cancer cell line Hela and the possible molecular mechanisms. Three HERC4-specific small interfering RNAs (siRNAs) were transfected into Hela cells, and HERC4 expression in the cells was examined with Western blotting. CCK-8 assay, annexin V-FITC/PI assay, and wound healing assay were used to assess the effect of HERC4 silencing on the proliferation, apoptosis and migration ability of Hela cells. The expression levels of cyclin D1 and Bcl-2 in the cells were detected using Western blotting. Transfection of siRNA-3 resulted in significantly decreased HERC4 protein expression (P<0.01). HERC4 silencing by siRNA-3 markedly suppressed the proliferation and migration of Hela cells, increased the apoptosis rate (P<0.01) and reduced the expression levels of cyclin D1 and Bcl-2 (P<0.01). Silencing of HERC4 efficiently inhibits the proliferation, migration, and invasion of Hela cells in vitro, and the underlying mechanisms may involve the down-regulation of cyclin D1 and Bcl-2.

Immunohistochemical estimation of cell cycle phase in laryngeal neoplasia

PubMed Central

Chatrath, P; Scott, I S; Morris, L S; Davies, R J; Bird, K; Vowler, S L; Coleman, N

2006-01-01

We previously developed an immunohistochemical method for estimating cell cycle state and phase in tissue samples, including biopsies that are too small for flow cytometry. We have used our technique to examine whether primary abnormalities of the cell cycle exist in laryngeal neoplasia. Antibodies against the markers of cell cycle entry, minichromosome maintenance protein-2 (Mcm-2) and Ki67, and putative markers of cell cycle phase, cyclin D1 (G1-phase), cyclin A (S-phase), cyclin B1 (G2-phase) and phosphohistone H3 (Mitosis) were applied to paraffin-embedded sections of normal larynx (n=8), laryngeal dysplasia (n=10) and laryngeal squamous cell carcinoma (n=10). Cells expressing each marker were determined as a percentage of total cells, termed the labelling index (LI), and as a percentage of Mcm-2-positive cells, termed the labelling fraction (LF). The frequency of coexpression of each putative phase marker was investigated by confocal microscopy. There was a correlation between Mcm-2 and Ki67 LIs (ρ=0.93) but Mcm-2 LIs were consistently higher. All cells expressing a phase marker coexpressed Mcm-2, whereas Ki67 was not expressed in a proportion of these cells. The putative phase markers showed little coexpression. Labelling index values increased on progression from normal larynx through laryngeal dysplasia to squamous cell carcinoma for Mcm-2 (P=0.001), Ki67 (P=0.0002), cyclin D1 (P=0.015), cyclin A (P=0.0001) and cyclin B1 (P=0.0004). There was no evidence of an increase in the LF for any phase marker. Immunohistochemistry can be used to estimate cell cycle state and phase in laryngeal biopsies. Our data argues against primary cell cycle phase abnormalities in laryngeal neoplasia. PMID:16832409

Formononetin induces cell cycle arrest of human breast cancer cells via IGF1/PI3K/Akt pathways in vitro and in vivo.

PubMed

Chen, J; Zeng, J; Xin, M; Huang, W; Chen, X

2011-09-01

Formononetin is one of the main components of red clover plants, and is considered as a typical phytoestrogen. This study further investigated that formononetin inactivated IGF1/IGF1R-PI3K/Akt pathways and decreased cyclin D1 mRNA and protein expression in human breast cancer cells in vitro and in vivo. MCF-7 cells were treated with different concentrations of formononetin. The proliferation of the cells treated with formononetin was tested by MTT assay. The cell cycle in the treated cells was examined by flow cytometry. The levels of p-IGF-1 R, p-Akt, and cyclin D1 protein expression and cyclin D1 mRNA expression in the treated cells were determined by Western blot and RT-PCR, respectively. In addition, the antitumor activity of formononetin was evaluated in nude mice bearing orthotopic tumor implants. Compared with the control, formononetin inhibited the proliferation of MCF-7 cells and effectively induced cell cycle arrest. The levels of p-IGF-1 R, p-Akt, cyclin D1 protein expression, and cyclin D1 mRNA expression were also downregulated. On the other hand, formononetin also prevented the tumor growth of human breast cancer cells in nude mouse xenografts. These results show that formononetin causes cell cycle arrest at the G0/G1 phase by inactivating IGF1/IGF1R-PI3K/Akt pathways and decreasing cyclin D1 mRNA and protein expression, indicating the use of formononetin in the prevention of breast cancer carcinogenesis. Georg Thieme Verlag KG Stuttgart · New York.

Multiple Mechanisms Are Involved in 6-Gingerol-Induced Cell Growth Arrest and Apoptosis in Human Colorectal Cancer Cells

PubMed Central

Lee, Seong-Ho; Cekanova, Maria; Baek, Seung Joon

2008-01-01

6-Gingerol, a natural product of ginger, has been known to possess anti-tumorigenic and pro-apoptotic activities. However, the mechanisms by which it prevents cancer are not well understood in human colorectal cancer. Cyclin D1 is a proto-oncogene that is overexpressed in many cancers and plays a role in cell proliferation through activation by β-catenin signaling. Nonsteroidal anti-inflammatory drug (NSAID)-activated gene-1 (NAG-1) is a cytokine associated with pro-apoptotic and anti-tumorigenic properties. In the present study, we examined whether 6-gingerol influences cyclin D1 and NAG-1 expression and determined the mechanisms by which 6-gingerol affects the growth of human colorectal cancer cells in vitro. 6-Gingerol treatment suppressed cell proliferation and induced apoptosis and G1 cell cycle arrest. Subsequently, 6-gingerol suppressed cyclin D1 expression and induced NAG-1 expression. Cyclin D1 suppression was related to inhibition of β-catenin translocation and cyclin D1 proteolysis. Furthermore, experiments using inhibitors and siRNA transfection confirm the involvement of the PKCε and glycogen synthase kinase (GSK)-3β pathways in 6-gingerol-induced NAG-1 expression. The results suggest that 6-gingerol stimulates apoptosis through upregulation of NAG-1 and G1 cell cycle arrest through downregulation of cyclin D1. Multiple mechanisms appear to be involved in 6-gingerol action, including protein degradation as well as β-catenin, PKCε, and GSK-3β pathways. PMID:18058799

Human T-cell leukemia virus type 1 Tax and cell cycle progression: role of cyclin D-cdk and p110Rb.

PubMed

Neuveut, C; Low, K G; Maldarelli, F; Schmitt, I; Majone, F; Grassmann, R; Jeang, K T

1998-06-01

Human T-cell leukemia virus type 1 is etiologically linked to the development of adult T-cell leukemia and various human neuropathies. The Tax protein of human T-cell leukemia virus type I has been implicated in cellular transformation. Like other oncoproteins, such as Myc, Jun, and Fos, Tax is a transcriptional activator. How it mechanistically dysregulates the cell cycle is unclear. Previously, it was suggested that Tax affects cell-phase transition by forming a direct protein-protein complex with p16(INK4a), thereby inactivating an inhibitor of G1-to-S-phase progression. Here we show that, in T cells deleted for p16(INK4a), Tax can compel an egress of cells from G0/G1 into S despite the absence of serum. We also show that in undifferentiated myocytes, expression of Tax represses cellular differentiation. In both settings, Tax expression was found to increase cyclin D-cdk activity and to enhance pRb phosphorylation. In T cells, a Tax-associated increase in steady-state E2F2 protein was also documented. In searching for a molecular explanation for these observations, we found that Tax forms a protein-protein complex with cyclin D3, whereas a point-mutated and transcriptionally inert Tax mutant failed to form such a complex. Interestingly, expression of wild-type Tax protein in cells was also correlated with the induction of a novel hyperphosphorylated cyclin D3 protein. Taken together, these findings suggest that Tax might directly influence cyclin D-cdk activity and function, perhaps by a route independent of cdk inhibitors such as p16(INK4a).

Chemopreventive agents alters global gene expression pattern: predicting their mode of action and targets.

PubMed

Narayanan, Bhagavathi A

2006-12-01

Chemoprevention has the potential to be a major component of colon, breast, prostate and lung cancer control. Epidemiological, experimental, and clinical studies provide evidence that antioxidants, anti-inflammatory agents, n-3 polyunsaturated fatty acids and several other phytochemicals possess unique modes of action against cancer growth. However, the mode of action of several of these agents at the gene transcription level is not completely understood. Completion of the human genome sequence and the advent of DNA microarrays using cDNAs enhanced the detection and identification of hundreds of differentially expressed genes in response to anticancer drugs or chemopreventive agents. In this review, we are presenting an extensive analysis of the key findings from studies using potential chemopreventive agents on global gene expression patterns, which lead to the identification of cancer drug targets. The summary of the study reports discussed in this review explains the extent of gene alterations mediated by more than 20 compounds including antioxidants, fatty acids, NSAIDs, phytochemicals, retinoids, selenium, vitamins, aromatase inhibitor, lovastatin, oltipraz, salvicine, and zinc. The findings from these studies further reveal the utility of DNA microarray in characterizing and quantifying the differentially expressed genes that are possibly reprogrammed by the above agents against colon, breast, prostate, lung, liver, pancreatic and other cancer types. Phenolic antioxidant resveratrol found in berries and grapes inhibits the formation of prostate tumors by acting on the regulatory genes such as p53 while activating a cascade of genes involved in cell cycle and apoptosis including p300, Apaf-1, cdk inhibitor p21, p57 (KIP2), p53 induced Pig 7, Pig 8, Pig 10, cyclin D, DNA fragmentation factor 45. The group of genes significantly altered by selenium includes cyclin D1, cdk5, cdk4, cdk2, cdc25A and GADD 153. Vitamine D shows impact on p21(Waf1/Cip1) p27 cyclin B and cyclin A1. Genomic expression profile with vitamin D indicated differential expression of gene targets such as c-JUN, JUNB, JUND, FREAC-1/FoxF1, ZNF-44/KOX7, plectin, filamin, and keratin-13, involved in antiproliferative, differentiation pathways. The agent UBEIL has a remarkable effect on cyclin D1. Curcumin mediated NrF2 pathway significantly altered p21(Waf1/Cip1) levels. Aromatase inhibitors affected the expression of cyclin D1. Interestingly, few dietary compounds listed in this review also have effect on APC, cdk inhibitors p21(Waf1/Cip1) and p27. Tea polyphenol EGCG has a significant effect on TGF-beta expression, while several other earlier studies have shown its effect on cell cycle regulatory proteins. This review article reveals potential chemoprevention drug targets, which are mainly centered on cell cycle regulatory pathway genes in cancer.

Tax-dependent stimulation of G1 phase-specific cyclin-dependent kinases and increased expression of signal transduction genes characterize HTLV type 1-transformed T cells.

PubMed

Haller, K; Ruckes, T; Schmitt, I; Saul, D; Derow, E; Grassmann, R

2000-11-01

Human T cell leukemia virus protein induces T cells to permanent IL-2-dependent growth. These cells occasionally convert to factor independence. The viral oncoprotein Tax acts as an essential growth factor of transformed lymphocytes and stimulates the cell cycle in the G(1) phase. In T cells and fibroblasts Tax enhances the activity of the cyclin-dependent kinases (CDK) CDK4 and CDK6. These kinases, which require binding to cyclin D isotypes for their activity, control the G(1) phase. Coimmunoprecipitation from these cells revealed that Tax associates with cyclin D3/CDK6, suggesting a direct activation of this kinase. The CDK stimulation may account in part for the mitogenic Tax effect, which causes IL-2-dependent T cell growth by Tax. To address the conversion to IL-2-independent proliferation and to identify overexpressed genes, which contribute to the transformed growth, the gene expression patterns of HTLV-1-transformed T cells were compared with that of peripheral blood lymphocytes. Potentially overexpressed cDNAs were cloned, sequenced, and used to determine the RNA expression. Genes found to be up-regulated are involved in signal transduction (STAT5a, cyclin G(1), c-fgr, hPGT) and also glycoprotein synthesis (LDLC, ribophorin). Many of these are also activated during T cell activation and implicated in the regulation of growth and apoptosis. The transcription factor STAT5a, which is involved in IL-2 signaling, was strongly up-regulated only in IL-2-independent cells, thus suggesting that it contributes to factor-independent growth. Thus, the differentially expressed genes could cooperate with the Tax-induced cell cycle stimulation in the maintenance of IL-2-dependent and IL-2-independent growth of HTLV-transformed lymphocytes.

Cyclin D1-AR Crosstalk: Potential Implications for Therapeutic Response in Prostate Cancer

DTIC Science & Technology

2013-06-01

expression of degradation- resistant and –proficient alleles of cyclin D1 in xenograft model (months 18 -21) B. Randomize mice in 6 groups: intact...inhibition of cyclin-dependent kinases 4 and 6 arrests the growth of glioblastoma multiforme intracranial xenografts . Cancer Res 2010; 70: 3228–3238. 33...cancer, cyclin D1 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18 . NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON USAMRMC a

Msx homeobox genes inhibit differentiation through upregulation of cyclin D1.

PubMed

Hu, G; Lee, H; Price, S M; Shen, M M; Abate-Shen, C

2001-06-01

During development, patterning and morphogenesis of tissues are intimately coordinated through control of cellular proliferation and differentiation. We describe a mechanism by which vertebrate Msx homeobox genes inhibit cellular differentiation by regulation of the cell cycle. We show that misexpression of Msx1 via retroviral gene transfer inhibits differentiation of multiple mesenchymal and epithelial progenitor cell types in culture. This activity of Msx1 is associated with its ability to upregulate cyclin D1 expression and Cdk4 activity, while Msx1 has minimal effects on cellular proliferation. Transgenic mice that express Msx1 under the control of the mouse mammary tumor virus long terminal repeat (MMTV LTR) display impaired differentiation of the mammary epithelium during pregnancy, which is accompanied by elevated levels of cyclin D1 expression. We propose that Msx1 gene expression maintains cyclin D1 expression and prevents exit from the cell cycle, thereby inhibiting terminal differentiation of progenitor cells. Our model provides a framework for reconciling the mutant phenotypes of Msx and other homeobox genes with their functions as regulators of cellular proliferation and differentiation during embryogenesis.

Effects of PTHrP on chondrocytes of sika deer antler.

PubMed

Guo, Bin; Wang, Shou-Tang; Duan, Cui-Cui; Li, Dang-Dang; Tian, Xue-Chao; Wang, Qu-Yuan; Yue, Zhan-Peng

2013-11-01

Parathyroid-hormone-related peptide (PTHrP) is an important regulator of chondrocyte differentiation in growth plates but little is known about its role in deer antler cartilage. The aim of the present study was to use the deer antler as a model to determine the possible role of PTHrP in regulating chondrocyte differentiation of deer antler. PTHrP and its receptor PTH1R mRNA were highly expressed in the perichondrium and cartilage of sika deer antler, as shown by in situ hybridization. Chondrocytes of deer antler were identified by toluidine blue staining of glycosaminoglycan and immunocytochemical staining of type II collagen (Col II). Treatment with PTHrP (1-34) reduced the expression of prehypertrophic chondrocyte marker Col IX and hypertrophic chondrocyte marker Col X. In order to confirm the mechanism of action of PTHrP, we initially examined the expression of cyclin D1, Bcl-2 and runt-related transcription factor 2 (Runx2) in sika deer antler by in situ hybridization and found that cyclin D1, Runx2 and Bcl-2 mRNA were also expressed in antler chondrocytes. Exogenous PTHrP induced the expression of cyclin D1 and Bcl-2 mRNA by various signalling pathways, whereas it inhibited Runx2 expression through PKA, p38MAPK, MEK and PI3K signalling pathways. Thus, PTHrP might promote the proliferation of antler chondrocytes and prevent their differentiation; it might furthermore influence the growth and development of sika deer antler.

Activation of the Wnt/{beta}-catenin signaling pathway is associated with glial proliferation in the adult spinal cord of ALS transgenic mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Yanchun; Department of Histology and Embryology, Shandong University School of Medicine, Jinan, Shandong; Guan, Yingjun, E-mail: guanyj@wfmc.edu.cn

Highlights: Black-Right-Pointing-Pointer Wnt3a and Cyclin D1 were upregulated in the spinal cord of the ALS mice. Black-Right-Pointing-Pointer {beta}-catenin translocated from the cell membrane to the nucleus in the ALS mice. Black-Right-Pointing-Pointer Wnt3a, {beta}-catenin and Cyclin D1 co-localized for astrocytes were all increased. Black-Right-Pointing-Pointer BrdU/Cyclin D1 double-positive cells were increased in the spinal cord of ALS mice. Black-Right-Pointing-Pointer BrdU/Cyclin D1/GFAP triple-positive cells were detected in the ALS mice. -- Abstract: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the progressive and fatal loss of motor neurons. In ALS, there is a significant cell proliferation in response to neurodegeneration; however,more » the exact molecular mechanisms of cell proliferation and differentiation are unclear. The Wnt signaling pathway has been shown to be involved in neurodegenerative processes. Wnt3a, {beta}-catenin, and Cyclin D1 are three key signaling molecules of the Wnt/{beta}-catenin signaling pathway. We determined the expression of Wnt3a, {beta}-catenin, and Cyclin D1 in the adult spinal cord of SOD1{sup G93A} ALS transgenic mice at different stages by RT-PCR, Western blot, and immunofluorescence labeling techniques. We found that the mRNA and protein of Wnt3a and Cyclin D1 in the spinal cord of the ALS mice were upregulated compared to those in wild-type mice. In addition, {beta}-catenin translocated from the cell membrane to the nucleus and subsequently activated transcription of the target gene, Cyclin D1. BrdU and Cyclin D1 double-positive cells were increased in the spinal cord of these mice. Moreover, Wnt3a, {beta}-catenin, and Cyclin D1 were also expressed in both neurons and astrocytes. The expression of Wnt3a, {beta}-catenin or Cyclin D1 in mature GFAP{sup +} astrocytes increased. Moreover, BrdU/Cyclin D1/GFAP triple-positive cells were detected in the ALS mice. Our findings suggest that neurodegeneration activates the Wnt/{beta}-catenin signaling pathway, which is associated with glial proliferation in the adult spinal cord of ALS transgenic mice. This mechanism may be significant in clinical gene therapy.« less

DEC1 regulates breast cancer cell proliferation by stabilizing cyclin E protein and delays the progression of cell cycle S phase

PubMed Central

Bi, H; Li, S; Qu, X; Wang, M; Bai, X; Xu, Z; Ao, X; Jia, Z; Jiang, X; Yang, Y; Wu, H

2015-01-01

Breast cancer that is accompanied by a high level of cyclin E expression usually exhibits poor prognosis and clinical outcome. Several factors are known to regulate the level of cyclin E during the cell cycle progression. The transcription factor DEC1 (also known as STRA13 and SHARP2) plays an important role in cell proliferation and apoptosis. Nevertheless, the mechanism of its role in cell proliferation is poorly understood. In this study, using the breast cancer cell lines MCF-7 and T47D, we showed that DEC1 could inhibit the cell cycle progression of breast cancer cells independently of its transcriptional activity. The cell cycle-dependent timing of DEC1 overexpression could affect the progression of the cell cycle through regulating the level of cyclin E protein. DEC1 stabilized cyclin E at the protein level by interacting with cyclin E. Overexpression of DEC1 repressed the interaction between cyclin E and its E3 ligase Fbw7α, consequently reducing the level of polyunbiquitinated cyclin E and increased the accumulation of non-ubiquitinated cyclin E. Furthermore, DEC1 also promoted the nuclear accumulation of Cdk2 and the formation of cyclin E/Cdk2 complex, as well as upregulating the activity of the cyclin E/Cdk2 complex, which inhibited the subsequent association of cyclin A with Cdk2. This had the effect of prolonging the S phase and suppressing the growth of breast cancers in a mouse xenograft model. These events probably constitute the essential steps in DEC1-regulated cell proliferation, thus opening up the possibility of a protein-based molecular strategy for eliminating cancer cells that manifest a high-level expression of cyclin E. PMID:26402517

Smad, PI3K/Akt, and Wnt-dependent signaling pathways are involved in BMP-4-induced ESC self-renewal.

PubMed

Lee, Min Young; Lim, Hyun Woo; Lee, Sang Hun; Han, Ho Jae

2009-08-01

It is known that bone morphogenetic protein 4 (BMP-4) has a diverse effect on ESCs. However, its precise mechanism in mouse ESCs is not fully understood. We evaluated the effect of BMP-4 on ESC proliferation and its related signal cascades in this study. BMP-4 significantly increased the level of [(3)H]-thymidine incorporation in time- (> or =8 hours) and dose- (> or =10 ng/ml) dependent manners. Additionally, BMP-4 increased cyclin D1 and decreased p27(kip1) expression values in a time-dependent manner. The increases in BMP-4-induced [(3)H]-thymidine incorporation and cyclin D1 expression were inhibited by the BMP-4 receptor antagonist noggin. BMP-4 increased Wnt1 expression. Wnt1 expression was attenuated by Smad4 small interfering RNA (siRNA), and BMP-4-induced cyclin D1 expression was inhibited by Smad4 and Wnt1 siRNAs. BMP-4 also activated beta-catenin, which was blocked by Smad4 and Wnt1 siRNAs. In addition, BMP-4 induced Akt phosphorylation. BMP-4-induced beta-catenin activation and cyclin D1 expression were attenuated by phosphatidyl inositol 3-kinase (PI3K) siRNA and Akt inhibitor. Additionally, downregulation of Smad4, Wnt1, and PI3K expression by siRNA decreased the levels of pluripotency marker mRNAs of ESCs, including Oct4, Sox2, and FoxD3. Our results suggested that BMP-4-induced [(3)H]-thymidine incorporation was significantly attenuated by Smad4, Wnt1, and PI3K knockdown. In conclusion, BMP-4 contributed to the maintenance of cell proliferation and the pluripotent state by Smad, PI3K/Akt, and Wnt1/beta-catenin in mouse ESCs.

BmCyclin B and BmCyclin B3 are required for cell cycle progression in the silkworm, Bombyx mori.

PubMed

Pan, Minhui; Hong, Kaili; Chen, Xiangyun; Pan, Chun; Chen, Xuemei; Kuang, Xiuxiu; Lu, Cheng

2013-04-01

Cyclin B is an important regulator of the cell cycle G2 to M phase transition. The silkworm genomic database shows that there are two Cyclin B genes in the silkworm (Bombyx mori), BmCyclin B and BmCyclin B3. Using silkworm EST data, the cyclin B3 (EU074796) gene was cloned. Its complete cDNA was 1665 bp with an ORF of 1536 bp derived from seven exons and six introns. The BmCyclin B3 gene encodes 511 amino acids, and the predicted molecular weight is 57.8 kD with an isoelectric point of 9.18. The protein contains one protein damage box and two cyclin boxes. RNA interference-mediated reduction of BmCyclin B and BmCyclin B3 expression induced cell cycle arrest in G2 or M phase in BmN-SWU1 cells, thus inhibiting cell proliferation. These results suggest that BmCyclin B and BmCyclin B3 are necessary for completing the cell cycle in silkworm cells.

Regulation of proliferation in developing human tooth germs by MSX homeodomain proteins and cyclin-dependent kinase inhibitor p19INK4d.

PubMed

Kero, Darko; Vukojevic, Katarina; Stazic, Petra; Sundov, Danijela; Mardesic Brakus, Snjezana; Saraga-Babic, Mirna

2017-10-02

Before the secretion of hard dental tissues, tooth germs undergo several distinctive stages of development (dental lamina, bud, cap and bell). Every stage is characterized by specific proliferation patterns, which is regulated by various morphogens, growth factors and homeodomain proteins. The role of MSX homeodomain proteins in odontogenesis is rather complex. Expression domains of genes encoding for murine Msx1/2 during development are observed in tissues containing highly proliferative progenitor cells. Arrest of tooth development in Msx knockout mice can be attributed to impaired proliferation of progenitor cells. In Msx1 knockout mice, these progenitor cells start to differentiate prematurely as they strongly express cyclin-dependent kinase inhibitor p19 INK4d . p19 INK4d induces terminal differentiation of cells by blocking the cell cycle in mitogen-responsive G1 phase. Direct suppression of p19 INK4d by Msx1 protein is, therefore, important for maintaining proliferation of progenitor cells at levels required for the normal progression of tooth development. In this study, we examined the expression patterns of MSX1, MSX2 and p19 INK4d in human incisor tooth germs during the bud, cap and early bell stages of development. The distribution of expression domains of p19 INK4d throughout the investigated period indicates that p19 INK4d plays active role during human tooth development. Furthermore, comparison of expression domains of p19 INK4d with those of MSX1, MSX2 and proliferation markers Ki67, Cyclin A2 and pRb, indicates that MSX-mediated regulation of proliferation in human tooth germs might not be executed by the mechanism similar to one described in developing tooth germs of wild-type mouse.

Endoglin inhibits ERK-induced c-Myc and cyclin D1 expression to impede endothelial cell proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Christopher C.; Bloodworth, Jeffrey C.; Mythreye, Karthikeyan

2012-08-03

Highlights: Black-Right-Pointing-Pointer Endoglin inhibits ERK activation in endothelial cells. Black-Right-Pointing-Pointer Endoglin is a regulator of c-Myc and cyclin D1 expression. Black-Right-Pointing-Pointer {beta}-arrestin2 interaction with endoglin is required for ERK/c-Myc repression. Black-Right-Pointing-Pointer Endoglin impedes cellular proliferation by targeting ERK-induced mitogenic signaling. -- Abstract: Endoglin is an endothelial-specific transforming growth factor beta (TGF-{beta}) co-receptor essential for angiogenesis and vascular remodeling. Endoglin regulates a wide range of cellular processes, including cell adhesion, migration, and proliferation, through TGF-{beta} signaling to canonical Smad and Smad-independent pathways. Despite its overall pro-angiogenic role in the vasculature, the underlying mechanism of endoglin action is poorly characterized. We previouslymore » identified {beta}-arrestin2 as a binding partner that causes endoglin internalization from the plasma membrane and inhibits ERK signaling towards endothelial migration. In the present study, we examined the mechanistic role of endoglin and {beta}-arrestin2 in endothelial cell proliferation. We show that endoglin impedes cell growth through sustained inhibition of ERK-induced c-Myc and cyclin D1 expression in a TGF-{beta}-independent manner. The down-regulation of c-Myc and cyclin D1, along with growth-inhibition, are reversed when the endoglin/{beta}-arrestin2 interaction is disrupted. Given that TGF-{beta}-induced Smad signaling potently represses c-Myc in most cell types, our findings here show a novel mechanism by which endoglin augments growth-inhibition by targeting ERK and key downstream mitogenic substrates.« less

NF-{kappa}B p65 represses {beta}-catenin-activated transcription of cyclin D1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hwang, Injoo; Choi, Yong Seok; Jeon, Mi-Ya

2010-12-03

Research highlights: {yields} Cyclin D1 transcription is directly activated by {beta}-catenin; however, {beta}-catenin-induced cyclin D1 transcription is reduced by NF-{kappa}B p65. {yields} Protein-protein interaction between NF-{kappa}B p65 and {beta}-catenin might be responsible for p65-mediated repression of cyclin D1. {yields} One of five putative binding sites, located further upstream of other sites, is the major {beta}-catenin binding site in the cyclin D1 promoter. {yields} NF-{kappa}B binding site in cyclin D1 is occupied not only by p65 but also by {beta}-catenin, which is dynamically regulated by the signal. -- Abstract: Signaling crosstalk between the {beta}-catenin and NF-{kappa}B pathways represents a functional network.more » To test whether the crosstalk also occurs on their common target genes, the cyclin D1 promoter was used as a model because it contains binding sites for both proteins. {beta}-catenin activated transcription from the cyclin D1 promoter, while co-expression of NF-{kappa}B p65 reduced {beta}-catenin-induced transcription. Chromatin immunoprecipitation revealed lithium chloride-induced binding of {beta}-catenin on one of the T-cell activating factor binding sites. More interestingly, {beta}-catenin binding was greatly reduced by NF-{kappa}B p65, possibly by the protein-protein interaction between the two proteins. Such a dynamic and complex binding of {beta}-catenin and NF-{kappa}B on promoters might contribute to the regulated expression of their target genes.« less

Disrupted cell cycle arrest and reduced proliferation in corneal fibroblasts from GCD2 patients: A potential role for altered autophagy flux

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Seung-il; Dadakhujaev, Shorafidinkhuja; Maeng, Yong-Sun

Highlights: • Reduced cell proliferation in granular corneal dystrophy type 2. • Abnormal cell cycle arrest by defective autophagy. • Decreased Cyclin A1, B1, and D1 in Atg7 gene knockout cells. • Increase in p16 and p27 expressions were observed in Atg7 gene knockout cells. - Abstract: This study investigates the role of impaired proliferation, altered cell cycle arrest, and defective autophagy flux of corneal fibroblasts in granular corneal dystrophy type 2 (GCD2) pathogenesis. The proliferation rates of homozygous (HO) GCD2 corneal fibroblasts at 72 h, 96 h, and 120 h were significantly lower (1.102 ± 0.027, 1.397 ± 0.039,more » and 1.527 ± 0.056, respectively) than those observed for the wild-type (WT) controls (1.441 ± 0.029, 1.758 ± 0.043, and 2.003 ± 0.046, respectively). Flow cytometry indicated a decreased G{sub 1} cell cycle progression and the accumulation of cells in the S and G{sub 2}/M phases in GCD2 cells. These accumulations were associated with decreased levels of Cyclin A1, B1, and E1, and increased expression of p16 and p27. p21 and p53 expression was also significantly lower in GCD2 cells compared to the WT. Interestingly, treatment with the autophagy flux inhibitor, bafilomycin A{sub 1}, resulted in similarly decreased Cyclin A1, B1, D1, and p53 expression in WT fibroblasts. Furthermore, similar findings, including a decrease in Cyclin A1, B1, and D1 and an increase in p16 and p27 expression were observed in autophagy-related 7 (Atg7; known to be essential for autophagy) gene knockout cells. These data provide new insight concerning the role of autophagy in cell cycle arrest and cellular proliferation, uncovering a number of novel therapeutic possibilities for GCD2 treatment.« less

Rho/ROCK signaling in regulation of corneal epithelial cell cycle progression.

PubMed

Chen, Jian; Guerriero, Emily; Lathrop, Kira; SundarRaj, Nirmala

2008-01-01

The authors' previous study showed that the expression of a Rho-associated serine/threonine kinase (ROCK) is regulated during cell cycle progression in corneal epithelial cells. The present study was conducted to determine whether and how Rho/ROCK signaling regulates cell cycle progression. Rabbit corneal epithelial cells (RCECs) in culture were arrested in the G(0) phase of the cell cycle by serum deprivation and then allowed to re-enter the cell cycle in the presence or absence of the ROCK inhibitor (Y27632) in serum-supplemented medium. The number of cells in the S phase, the relative levels of specific cyclins and CDKs and their intracellular distribution, and the relative levels of mRNAs were determined by BrdU labeling, Western blot and immunocytochemical analyses, and real-time RT-PCR, respectively. ROCK inhibition delayed the progression of G(1) to S phase and led to a decrease in the number of RCECs entering the S phase between 12 and 24 hours from 31.5% +/- 4.5% to 8.1% +/- 2.6%. During the cell cycle progression, protein and mRNA levels of cyclin-D1 and -D3 and cyclin-dependent kinases CDK4 and CDK6 were significantly lower, whereas the protein levels of the CDK inhibitor p27(Kip1) were higher in ROCK-inhibited cells. Intracellular mRNA or protein levels of cyclin-E and protein levels of CDK2 were not significantly affected, but their nuclear translocation was delayed by ROCK inhibition. ROCK signaling is involved in cell cycle progression in RCECs, possibly by upregulation of cyclin-D1 and -D3 and CDK4, -6, and -2; nuclear translocation of CDK2 and cyclin-E; and downregulation of p27(Kip1).

CARMA3 is overexpressed in colon cancer and regulates NF-{kappa}B activity and cyclin D1 expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miao, Zhifeng; Zhao, Tingting; Wang, Zhenning

2012-09-07

Highlights: Black-Right-Pointing-Pointer CARMA3 expression is elevated in colon cancers. Black-Right-Pointing-Pointer CARMA3 promotes proliferation and cell cycle progression in colon cancer cells. Black-Right-Pointing-Pointer CARMA3 upregulates cyclinD1 through NF-{kappa}B activation. -- Abstract: CARMA3 was recently reported to be overexpressed in cancers and associated with the malignant behavior of cancer cells. However, the expression of CARMA3 and its biological roles in colon cancer have not been reported. In the present study, we analyzed the expression pattern of CARMA3 in colon cancer tissues and found that CARMA3 was overexpressed in 30.8% of colon cancer specimens. There was a significant association between CARMA3 overexpression andmore » TNM stage (p = 0.0383), lymph node metastasis (p = 0.0091) and Ki67 proliferation index (p = 0.0035). Furthermore, knockdown of CARMA3 expression in HT29 and HCT116 cells with high endogenous expression decreased cell proliferation and cell cycle progression while overexpression of CARMA3 in LoVo cell line promoted cell proliferation and facilitated cell cycle transition. Further analysis showed that CARMA3 knockdown downregulated and its overexpression upregulated cyclin D1 expression and phospho-Rb levels. In addition, we found that CARMA3 depletion inhibited p-I{kappa}B levels and NF-{kappa}B activity and its overexpression increased p-I{kappa}B expression and NF-{kappa}B activity. NF-{kappa}B inhibitor BAY 11-7082 reversed the role of CARMA3 on cyclin D1 upregulation. In conclusion, our study found that CARMA3 is overexpressed in colon cancers and contributes to malignant cell growth by facilitating cell cycle progression through NF-{kappa}B mediated upregulation of cyclin D1.« less

Intact follicular maturation and defective luteal function in mice deficient for cyclin- dependent kinase-4.

PubMed

Moons, David S; Jirawatnotai, Siwanon; Tsutsui, Tateki; Franks, Roberta; Parlow, A F; Hales, Dale B; Gibori, Geula; Fazleabas, Asgerally T; Kiyokawa, Hiroaki

2002-02-01

Cell cycle progression of granulosa cells is critical for ovarian function, especially follicular maturation. During follicular maturation, FSH induces cyclin D2, which promotes G1 progression by activating cyclin-dependent kinase-4 (Cdk4). Because cyclin D2-deficient mice exhibit a block in follicular growth, cyclin D2/Cdk4 has been hypothesized to be required for FSH-dependent proliferation of granulosa cells. Here we investigate ovarian function in Cdk4-knockout mice we recently generated. Cdk4(-/-) females were sterile, but the morphology of their ovaries appeared normal before sexual maturation. The number of preovulatory follicles and the ovulation efficiency were modestly reduced in gonadotropin-treated Cdk4(-/-) mice. However, unlike cyclin D2-deficient mice, Cdk4(-/-) mice showed no obvious defect in FSH-induced proliferation of granulosa cells. Cdk4(-/-) ovaries displayed normal preovulatory expression of aromatase, PR, and cyclooxygenase-2. Postovulatory progesterone secretion was markedly impaired in Cdk4(-/-) mice, although granulosa cells initiated luteinization with induction of p450 side-chain cleavage cytochrome and p27(Kip1). Progesterone treatment rescued implantation and restored fertility in Cdk4(-/-) mice. Serum PRL levels after mating were significantly reduced in Cdk4(-/-) mice, suggesting the involvement of perturbed PRL regulation in luteal failure. Thus, Cdk4 is critical for luteal function, and some redundant protein(s) can compensate for the absence of Cdk4 in proliferation of granulosa cells.

Ethanol extracts from the branch of Taxillus yadoriki parasitic to Neolitsea sericea induces cyclin D1 proteasomal degradation through cyclin D1 nuclear export.

PubMed

Park, Su Bin; Park, Gwang Hun; Kim, Ha Na; Song, Hun Min; Son, Ho-Jun; Park, Ji Ae; Kim, Hyun-Seok; Jeong, Jin Boo

2018-06-20

Although the inhibitory effect of mistletoe on cancer cell growth has been reported, the underlying mechanisms to explain its anti-proliferative activity are not fully studied. Thus, we elucidated the potential molecular mechanism of the branch from Taxillus yadoriki (TY) parasitic to Neolitsea sericea (NS) (TY-NS-B) for the anti-proliferative effect. Anti-cell proliferative effect was evaluated by MTT assay. The change of cyclin D1 protein or mRNA level was evaluated by Western blot and RT-RCR, respectively. In comparison of anti-proliferative effect of TY from the host trees such as Cryptomeria japonica (CJ), Neolitsea sericea (NS), Prunus serrulata (PS), Cinnamomum camphora (CC) and Quercus acutissima (QA), TY-NS showed higher anti-cell proliferative effect than TY-CJ, TY-PS, TY-CC or TY-QA. In addition, the anti-proliferative effect of branch from TY from all host trees was better than leaves. Thus, we selected the branch from Taxillus yadoriki parasitic to Neolitsea sericea (TY-NS-B) for the further study. TY-NS-B inhibited the cell proliferation in the various cancer cells and downregulated cyclin D1 protein level. MG132 treatment attenuated cyclin D1 downregulation of cyclin D1 protein level by TY-NS-B. In addition, TY-NS-B increased threonine-286 (T286) phosphorylation of cyclin D1, and the mutation of T286 to alanine (T286A) blocked cyclin D1 proteasomal degradation by TY-NS-B. But the upstream factors related to cyclin D1 degradation such as ERK1/2, p38, JNK, GSK3β, PI3K, IκK or ROS did not affect cyclin D1 degradation by TY-NS-B. However, LMB treatment was observed to inhibit cyclin D1 degradation by TY-NS-B, and T286A blocked cyclin D1 degradation through suppressing cyclin D1 redistribution from nucleus to cytoplasm by TY-NS-B. In addition, TY-NS-B activated CRM1 expression. Our results suggest that TY-NS-B may suppress cell proliferation by downregulating cyclin D1 protein level through proteasomal degradation via T286 phosphorylation-dependent cyclin D1 nuclear export. These findings will provide the evidence that TY-NS-B has potential to be a candidate for the development of chemoprevention or therapeutic agents for human cancer.

PAC exhibits potent anti-colon cancer properties through targeting cyclin D1 and suppressing epithelial-to-mesenchymal transition.

PubMed

Al-Qasem, Abeer; Al-Howail, Huda A; Al-Swailem, Mashael; Al-Mazrou, Amer; Al-Otaibi, Basem; Al-Jammaz, Ibrahim; Al-Khalaf, Huda H; Aboussekhra, Abdelilah

2016-03-01

Colorectal cancer (CRC) is a major cause of cancer morbidity and mortality worldwide. Although response rates and overall survival have been improved in recent years, resistance to multiple drug combinations is inevitable. Therefore, the development of more efficient drugs, with fewer side effects is urgently needed. To this end, we have investigated in the present report the effect of PAC, a novel cucumin analogue, on CRC cells both in vitro and in vivo. We have shown that PAC induces apoptosis, mainly via the internal mitochondrial route, and inhibits cell proliferation through delaying the cell cycle at G2/M phase. Interestingly, the pro-apoptotic effect was mediated through STAT3-dependent down-regulation of cyclin D1 and its downstream target survivin. Indeed, change in the expression level of cyclin D1 modulated the expression of survivin and the response of CRC cells to PAC. Furthermore, using the ChIP assay, we have shown PAC-dependent reduction in the binding of STAT3 to the cyclin D1 promoter in vivo. Additionally, PAC suppressed the epithelial-to-mesenchymal process through down-regulating the mesenchymal markers (N-cadherin, vimentin and Twist1) and inhibiting the invasion/migration abilities of the CRC cells via repressing the pro-migration/invasion protein kinases AKT and ERK1/2. In addition, PAC inhibited tumor growth and repressed the JAK2/STAT3, AKT/mTOR and MEK/ERK pathways as well as their common downstream effectors cyclin D1 and survivin in humanized CRC xenografts. Collectively, these results indicate that PAC has potent anti-CRC effects, and therefore could constitute an effective alternative chemotherapeutic agent, which may consolidate the adjuvant treatment of colon cancer. © 2015 Wiley Periodicals, Inc.

Effect of fenhexamid and cyprodinil on the expression of cell cycle- and metastasis-related genes via an estrogen receptor-dependent pathway in cellular and xenografted ovarian cancer models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Go, Ryeo-Eun; Kim, Cho-Won; Choi, Kyung-Chul, E-mail: kchoi@cbu.ac.kr

ABSTRACT: Fenhexamid and cyprodinil are antifungal agents (pesticides) used for agriculture, and are present at measurable amounts in fruits and vegetables. In the current study, the effects of fenhexamid and cyprodinil on cancer cell proliferation and metastasis were examined. Additionally, the protein expression levels of cyclin D1 and cyclin E as well as cathepsin D were analyzed in BG-1 ovarian cancer cells that express estrogen receptors (ERs). The cells were cultured with 0.1% dimethyl sulfoxide (DMSO; control), 17β-estradiol (E2; 10{sup −9} M), and fenhexamid or cyprodinil (10{sup –5}–10{sup −7} M). Results of a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that fenhexamidmore » and cyprodinil increased BG-1 cell proliferation about 1.5 to 2 times similar to E2 (5 times) compared to the control. When the cells were co-treated with ICI 182,780 (10{sup −8} M), an ER antagonist, the proliferation of pesticide-treated BG-1 cells was decreased to the level of the control. A wound healing assay revealed that the pesticides reduced the disrupted area in the BG-1 cell monolayer similar to E2. Protein levels of cyclin D1 and E as well as cathepsin D were increased by fenhexamid and cyprodinil. This effect was reversed by co-treatment with ICI 182,780. In a xenograft mouse model with transplanted BG-1 cells, cyprodinil significantly increased tumor mass formation about 2 times as did E2 (6 times) compared to the vehicle (0.1% DMSO) over an 80-day period. In contrast, fenhexamid did not promote ovarian tumor formation in this mouse model. Cyprodinil also induced cell proliferation along with the expression of proliferating cell nuclear antigen (PCNA) and cathepsin D in tumor tissues similar to E2. Taken together, these results imply that fenhexamid and cyprodinil may have disruptive effects on ER-expressing cancer by altering the cell cycle- and metastasis-related gene expression via an ER-dependent pathway. - Highlights: • Fenhexamid and cyprodinil increased BG-1 cell proliferation via ER. • Two pesticides reduced the disrupted area in the BG-1 cell monolayer. • Cyclin D1 and E and cathepsin D proteins were induced by fenhexamid and cyprodinil. • Cyprodinil significantly increased tumor mass formation in a xenografted model. • Fenhexamid and cyprodinil may have disruptive effects on ER-expressing cancer.« less

RBP-J-interacting and tubulin-associated protein induces apoptosis and cell cycle arrest in human hepatocellular carcinoma by activating the p53–Fbxw7 pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Haihe; Yang, Zhanchun; Liu, Chunbo

2014-11-07

Highlights: • RITA overexpression increased protein expression of p53 and Fbxw7 and downregulated the expression of cyclin D1, cyclin E, CDK2, Hes-1 and NF-κB p65. • RITA can significantly inhibit the in vitro growth of SMMC7721 and HepG2 cells. • RITA exerts tumor-suppressive effects in hepatocarcinogenesis through induction of G0/G1 cell cycle arrest and apoptosis and suggest a therapeutic application of RITA in HCC. - Abstract: Aberrant Notch signaling is observed in human hepatocellular carcinoma (HCC) and has been associated with the modulation of cell growth. However, the role of Notch signaling in HCC and its underlying mechanism remain elusive.more » RBP-J-interacting and tubulin-associated (RITA) mediates the nuclear export of RBP-J to tubulin fibers and downregulates Notch-mediated transcription. In this study, we found that RITA overexpression increased protein expression of p53 and Fbxw7 and downregulated the expression of cyclin D1, cyclin E, CDK2, Hes-1 and NF-κB p65. These changes led to growth inhibition and induced G0/G1 cell cycle arrest and apoptosis in SMMC7721 and HepG2 cells. Our findings indicate that RITA exerts tumor-suppressive effects in hepatocarcinogenesis through induction of G0/G1 cell cycle arrest and apoptosis and suggest a therapeutic application of RITA in HCC.« less

Initiation and termination of DNA replication during S phase in relation to cyclins D1, E and A, p21WAF1, Cdt1 and the p12 subunit of DNA polymerase δ revealed in individual cells by cytometry

PubMed Central

Darzynkiewicz, Zbigniew; Zhao, Hong; Zhang, Sufang; Marietta, Y.W.T. Lee; Ernest, Y.C. Lee; Zhang, Zhongtao

2015-01-01

During our recent studies on mechanism of the regulation of human DNA polymerase δ in preparation for DNA replication or repair, multiparameter imaging cytometry as exemplified by laser scanning cytometry (LSC) has been used to assess changes in expression of the following nuclear proteins associated with initiation of DNA replication: cyclin A, PCNA, Ki-67, p21WAF1, DNA replication factor Cdt1 and the smallest subunit of DNA polymerase δ, p12. In the present review, rather than focusing on Pol δ, we emphasize the application of LSC in these studies and outline possibilities offered by the concurrent differential analysis of DNA replication in conjunction with expression of the nuclear proteins. A more extensive analysis of the data on a correlation between rates of EdU incorporation, likely reporting DNA replication, and expression of these proteins, is presently provided. New data, specifically on the expression of cyclin D1 and cyclin E with respect to EdU incorporation as well as on a relationship between expression of cyclin A vs. p21WAF1 and Ki-67 vs. Cdt1, are also reported. Of particular interest is the observation that this approach makes it possible to assess the temporal sequence of degradation of cyclin D1, p21WAF1, Cdt1 and p12, each with respect to initiation of DNA replication and with respect to each other. Also the sequence or reappearance of these proteins in G2 after termination of DNA replication is assessed. The reviewed data provide a more comprehensive presentation of potential markers, whose presence or absence marks the DNA replicating cells. Discussed is also usefulness of these markers as indicators of proliferative activity in cancer tissues that may bear information on tumor progression and have a prognostic value. PMID:26059433

Initiation and termination of DNA replication during S phase in relation to cyclins D1, E and A, p21WAF1, Cdt1 and the p12 subunit of DNA polymerase δ revealed in individual cells by cytometry.

PubMed

Darzynkiewicz, Zbigniew; Zhao, Hong; Zhang, Sufang; Lee, Marietta Y W T; Lee, Ernest Y C; Zhang, Zhongtao

2015-05-20

During our recent studies on mechanism of the regulation of human DNA polymerase δ in preparation for DNA replication or repair, multiparameter imaging cytometry as exemplified by laser scanning cytometry (LSC) has been used to assess changes in expression of the following nuclear proteins associated with initiation of DNA replication: cyclin A, PCNA, Ki-67, p21(WAF1), DNA replication factor Cdt1 and the smallest subunit of DNA polymerase δ, p12. In the present review, rather than focusing on Pol δ, we emphasize the application of LSC in these studies and outline possibilities offered by the concurrent differential analysis of DNA replication in conjunction with expression of the nuclear proteins. A more extensive analysis of the data on a correlation between rates of EdU incorporation, likely reporting DNA replication, and expression of these proteins, is presently provided. New data, specifically on the expression of cyclin D1 and cyclin E with respect to EdU incorporation as well as on a relationship between expression of cyclin A vs. p21(WAF1) and Ki-67 vs. Cdt1, are also reported. Of particular interest is the observation that this approach makes it possible to assess the temporal sequence of degradation of cyclin D1, p21(WAF1), Cdt1 and p12, each with respect to initiation of DNA replication and with respect to each other. Also the sequence or reappearance of these proteins in G2 after termination of DNA replication is assessed. The reviewed data provide a more comprehensive presentation of potential markers, whose presence or absence marks the DNA replicating cells. Discussed is also usefulness of these markers as indicators of proliferative activity in cancer tissues that may bear information on tumor progression and have a prognostic value.

Minichromosome maintenance (Mcm) proteins, cyclin B1 and D1, phosphohistone H3 and in situ DNA replication for functional analysis of vulval intraepithelial neoplasia.

PubMed

Davidson, E J; Morris, L S; Scott, I S; Rushbrook, S M; Bird, K; Laskey, R A; Wilson, G E; Kitchener, H C; Coleman, N; Stern, P L

2003-01-27

Vulval intraepithelial neoplasia (VIN) is defined histopathologically by distinctive abnormalities of cellular maturation and differentiation. To investigate the functional properties of VIN, the expression of several proteins involved in the regulation of the cell cycle as well as in situ DNA replication competence was analysed by immunohistochemistry. Snap-frozen vulval biopsies were graded as normal squamous epithelium (n=6), undifferentiated HPV positive VIN 1 (n=3), VIN 2 (n=8) and VIN 3 (n=20). Immunohistochemistry was performed using the following markers: cyclin D1 (expressed in middle/late G1), cyclin B1 (expressed in G2/early M), phosphorylated histone H3 (expressed during mitosis) and minichromosome maintenance (Mcm) proteins 2 and 5 (expressed during the cell cycle, but not in differentiated or quiescent cells). In situ DNA replication competence was used to identify S-phase cells. The percentage of positively stained nuclei in three representative microscopic fields was calculated per biopsy. In normal vulva, the expression of all markers was restricted to the proliferative compartment of the basal layer of the epithelium. In contrast in high-grade VIN, the majority of epithelial cells expressed the Mcm proteins from basal to superficial layer. The detection of cyclins B1 and D1, phospho-histone H3 and in situ DNA replication was also found through the full thickness of these lesions but by a lower proportion of the cells. This is consistent with these markers providing a series of 'snapshots' of the cell cycle status of individual cells. The low-grade VIN showed reduced expression of the cell cycle markers in relation to the level of dysplasia. The combination of these analyses establishes that the majority of VIN cells remain in a functional replicative or prereplicative state of the cell cycle. Clinical application of these analyses may provide a basis for improved diagnosis of VIN.

Effect and mechanism of PAR-2 on the proliferation of esophageal cancer cells.

PubMed

Quanjun, D; Qingyu, Z; Qiliang, Z; Liqun, X; Jinmei, C; Ziquan, L; Shike, H

2016-11-01

Esophageal Cancer (EC) is a common malignant tumor occurred in the digestive tract. In this study, we investigated the mechanism of Protease Activated Receptor 2 (PAR-2) on the proliferation of esophageal cancer cell. Transfected esophageal cancer (EC) cell (PAR-2shRNA EC109) was established with low stable PAR-2 expression. EC109 cell was treated with PAR-2 agonist, PAR-2 anti-agonist and MAPK inhibitor respectively; Untreated EC109 cell (blank control) and PAR-2shRNA EC109 cell were used for analysis also. The mRNA expressions of PAR-2, ERK1, Cyclin D1, and c-fos in each group were detected by reverse transcript and polymerase chain reaction. Western blot was used to detect the protein expressions in each group. The cell growth curves were drawn to compare the cell growth. Compared with the blank control, the mRNA and protein expressions of PAR-2, Cyclin D1, and c-fos in PAR-2 agonist group increased significantly (p < 0.05), while decreased significantly in PAR-2shRNA EC109 cell and MAPK inhibitor group (p < 0.05). The mRNA expression of ERK1 and protein expression of p-ERK1 increased in PAR-2 agonist group, decreased in PAR-2shRNA EC109 cell and MAPK inhibitor group when compared with blank control (p < 0.05). The growth of cells was upward in PAR-2 agonist group at cell growth phase when compared with blank control, while decreased in PAR-2 shRNA EC109 cell and MAPK inhibitor group with statistical difference (p < 0.05). PAR-2 regulate cell proliferation through the MAPK pathway in esophageal carcinoma cell, and Cyclin D1, c-fos are involved in this process.

Transcriptional and post-transcriptional down-regulation of cyclin D1 contributes to C6 glioma cell differentiation induced by forskolin.

PubMed

He, Songmin; Zhu, Wenbo; Zhou, Yuxi; Huang, Yijun; Ou, Yanqiu; Li, Yan; Yan, Guangmei

2011-09-01

Malignant gliomas are the most common and lethal intracranial tumors, and differentiation therapy shows great potential to be a promising candidate for their treatment. Here, we have elaborated that a PKA activator, forskolin, represses cell growth via cell cycle arrest in the G0/G1 phase and induces cell differentiation characteristic with elongated processes and restoration of GFAP expression. In mechanisms, we verified that forskolin significantly diminishes the mRNA and protein level of a key cell cycle regulator cyclin D1, and maintenance of low cyclin D1 expression level was required for forskolin-induced proliferation inhibition and differentiation by gain and loss of function approaches. In addition, that forskolin down-regulated the cyclin D1 by proteolytic (post-transcriptional) mechanisms was dependent on GSK-3β activation at Ser9. The pro-differentiation activity of forskolin and related molecular mechanisms imply that forskolin can be developed into a candidate for the future in differentiation therapy of glioma, and cyclin D1 is a promising target for pro-differentiation strategy. Copyright © 2011 Wiley-Liss, Inc.

Schisantherin A Improves Learning and Memory of Mice with D-Galactose-Induced Learning and Memory Impairment through Its Antioxidation and Regulation of p19/p53/p21/Cyclin D1/CDK4/RB Gene Expressions.

PubMed

Liu, Cong; Sun, Weijing; Li, Ning; Gao, Jiaqi; Yu, Chunyan; Wang, Chunmei; Sun, Jinghui; Jing, Shu; Chen, Jianguang; Li, He

2018-05-31

Schisantherin A (SCA) was evaluated for possible function in restoring the learning and memory impairment induced by D-galactose in mice. ICR mice were treated with D-galactose subcutaneously (220 mg·kg -1 ), and followed by SCA in different doses (1.25, 2.50 and 5.00 mg·kg -1 , administered orally) for 42 days. Effects of SCA on learning and memory were examined by step-through tests and Morris water maze tests. The activity of superoxide dismutase (SOD), the content of malondialdehyde (MDA) in the peripheral blood and hippocampus of mice were assayed by water-soluble tetrazolium-1 (WST-1) and thiobarbituric acid (TBA) methods. The contents of 8 hydroxy deoxy guanosine (8-OHdG) in the hippocampus of mice were detected by immunosorbent assay methods, respectively. Quantitative real-time PCR and Western Blot were respectively used to detect the expression of p19, p53, p21, cyclin D1, CDK4 and RB genes, and the phosphorylation of RB in the hippocampus of mice. We found that SCA significantly improved the learning and memory impairment induced by D-galactose in mice. After SCA treatment, SOD activity was increased and the content of MDA was decreased in both peripheral blood and hippocampus of mice. 8-OHDG content was also decreased in the hippocampus of mice. Furthermore, the expression of p19, p53 and p21 genes was reduced and the expression of cyclin D1 and CDK4 and the phosphorylation of RB protein were elevated in the hippocampus. SCA may improve the learning and memory impairment induced by D-galactose by enhancing the antioxidant capacity, and regulating the expression of p19/p53/p21/cyclinD1/CDK4 genes, and the phosphorylation of RB protein in the hippocampus of mice.

Requirement of ClC-3 in G0/G1 to S Phase Transition Induced by IGF-1 via ERK1/2-Cyclins Cascade in Multiple Myeloma Cells.

PubMed

Du, Yu; Tu, Yong-Sheng; Tang, Yong-Bo; Huang, Yun-Ying; Zhou, Fang-Min; Tian, Tian; Li, Xiao-Yan

2018-06-01

ClC-3 is involved in the proliferation and migration of several cancer cells. However, ClC-3 expression and its role of cell-cycle control in multiple myeloma (MM) has not yet been investigated. MM cells were treated with different concentrations of IGF (30, 100, 300 ng/mL), and their proliferation was examined by CCK-8. The effects of ClC-3 on cell cycle progression was detected by flow cytometry. Western blot was used to analyze the relative levels of ClC3, CD138, P21, P27, CDK, p-Erk1/2, and t-Erk1/2 protein expression. Transfection of RPMI8226 with gpClC-3 cDNA and siRNA alters the expression of ClC-3. We compared the expression of ClC-3 in primary myeloma cells and in MM cell lines (U266 and RPMI8266) with that in normal plasma cells (PCs) from normal subjects and found that myeloma cells from patients and MM cell lines had significantly higher expression of ClC-3. Additionally, silencing of ClC-3 with the small interfering RNA (siRNA) that targets human ClC-3 decreased proliferation of RPMI8226 after IGF-1 treatment and slowed cell cycle progression from G0/G1 to S phase, which was associated with diminished phosphorylation of ERK1/2, down-expression of cyclin E, cyclin D1 and up-regulation of p27 and p21. By contrast, overexpression of ClC-3 potentiated cell proliferation induced by IGF-1, raised the percentage of S phase cells, enhanced phosphorylation of ERK1/2, downregulated p27 and p21 and upregulated cyclin E and cyclin D1. ClC-3 accelerated G0/G1 to S phase transition in the cell cycle by modulating ERK1/2 kinase activity and expression of G1/S transition related proteins, making ClC-3 an attractive therapeutic target in MM.

The assembly, activation, and substrate specificity of Cyclin D1/Cdk2 complexes

PubMed Central

Jahn, Stephan C.; Law, Mary E.; Corsino, Patrick E.; Rowe, Thomas C.; Davis, Bradley J.; Law, Brian K.

2013-01-01

Previous studies have shown conflicting data regarding Cyclin D1/Cdk2 complexes and, considering the widespread overexpression of Cyclin D1 in cancer, it is important to fully understand their relevance. While many have shown Cyclin D1/Cdk2 complexes to form active complexes, others have failed to show activity or association. Here, using a novel p21-PCNA fusion protein as well as p21 mutant proteins, we show that p21 is a required scaffolding protein, with Cyclin D1 and Cdk2 failing to complex in its absence. These p21/Cyclin D1/Cdk2 complexes are active and also bind the trimeric PCNA complex, with each trimer capable of independently binding distinct Cyclin/Cdk complexes. We also show that increased p21 levels due to treatment with chemotherapeutic agents result in increased formation and kinase activity of Cyclin D1/Cdk2 complexes, and that Cyclin D1/Cdk2 complexes are able to phosphorylate a number of substrates in addition to Rb. Nucleophosmin and Cdh1, two proteins important for centrosome replication and implicated in the chromosomal instability of cancer are shown to be phosphorylated by Cyclin D1/Cdk2 complexes. Additionally, PSF is identified as a novel Cdk2 substrate, being phosphorylated by Cdk2 complexed with either Cyclin E or Cyclin D1, and given the many functions of PSF, it could have important implications on cellular activity. PMID:23627734

Coordinated Expression of Cyclin-dependent Kinase-4 and its Regulators in Human Oral Tumors

PubMed Central

POI, MING J.; KNOBLOCH, THOMAS J.; SEARS, MARTA T.; UHRIG, LANA K.; WARNER, BLAKE M.; WEGHORST, CHRISTOPHER M.; LI, JUNAN

2014-01-01

Background/Aim While aberrant expression of cyclin-dependent kinase-4 (CDK4) has been found in squamous cell carcinoma of the head and neck (SCCHN), the associations between CDK4 and its regulators, namely, cyclin D1, cyclin E, gankyrin, SEI1, and BMI1 in gene expression remain to be explored. Herein we investigated the mRNA profiles of these oncogenes and their interrelations in different oral lesion tissues. Materials and Methods Thirty SCCHN specimens and patient-matched high at-risk mucosa (HARM) and 16 healthy control specimens were subjected to quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analyses. Results The mRNA levels of CDK4, cyclin D1, gankyrin, SEI1, BMI1 were significantly elevated in both HARM and SCCHN (in comparison with control specimens), and statistically significant correlations were found among these markers in gene expression. Conclusion Up-regulation of CDK4 and its regulators takes place in oral cancer progression in a coordinate manner, and HARM and SCCHN share a similar molecular signature within the CDK4-pRB pathway. PMID:24982332

Direct transdifferentiation of spermatogonial stem cells to morphological, phenotypic and functional hepatocyte-like cells via the ERK1/2 and Smad2/3 signaling pathways and the inactivation of cyclin A, cyclin B and cyclin E

PubMed Central

2013-01-01

Background Severe shortage of liver donors and hepatocytes highlights urgent requirement of extra-liver and stem cell source of hepatocytes for treating liver-related diseases. Here we hypothesized that spermatogonial stem cells (SSCs) can directly transdifferentiate to hepatic stem-like cells capable of differentiating into mature hepatocyte-like cells in vitro without an intervening pluripotent state. Results SSCs first changed into hepatic stem-like cells since they resembled hepatic oval cells in morphology and expressed Ck8, Ck18, Ck7, Ck19, OV6, and albumin. Importantly, they co-expressed CK8 and CK19 but not ES cell markers. Hepatic stem-like cells derived from SSCs could differentiate into small hepatocytes based upon their morphological features and expression of numerous hepatic cell markers but lacking of bile epithelial cell hallmarks. Small hepatocytes were further coaxed to differentiate into mature hepatocyte-like cells, as identified by their morphological traits and strong expression of Ck8, Ck18, Cyp7a1, Hnf3b, Alb, Tat, Ttr, albumin, and CYP1A2 but not Ck7 or CK19. Notably, these differentiated cells acquired functional attributes of hepatocyte-like cells because they secreted albumin, synthesized urea, and uptake and released indocyanine green. Moreover, phosphorylation of ERK1/2 and Smad2/3 rather than Akt was activated in hepatic stem cells and mature hepatocytes. Additionally, cyclin A, cyclin B and cyclin E transcripts and proteins but not cyclin D1 or CDK1 and CDK2 transcripts or proteins were reduced in mature hepatocyte-like cells or hepatic stem-like cells derived from SSCs compared to SSCs. Conclusions SSCs can transdifferentiate to hepatic stem-like cells capable of differentiating into cells with morphological, phenotypic and functional characteristics of mature hepatocytes via the activation of ERK1/2 and Smad2/3 signaling pathways and the inactivation of cyclin A, cyclin B and cyclin E. This study thus provides an invaluable source of mature hepatocytes for treating liver-related diseases and drug toxicity screening and offers novel insights into mechanisms of liver development and cell reprogramming. PMID:24047406

Downregulation of telomerase activity by diclofenac and curcumin is associated with cell cycle arrest and induction of apoptosis in colon cancer.

PubMed

Rana, Chandan; Piplani, Honit; Vaish, Vivek; Nehru, Bimla; Sanyal, S N

2015-08-01

Uncontrolled cell proliferation is the hallmark of cancer, and cancer cells have typically acquired damage to genes that directly regulate their cell cycles. The synthesis of DNA onto the end of chromosome during the replicative phase of cell cycle by telomerase may be necessary for unlimited proliferation of cells. Telomerase, a ribonucleoprotein enzyme is considered as a universal therapeutic target of cancer because of its preferential expression in cancer cells and its presence in 90 % of tumors. We studied the regulation of telomerase and telomerase reverse transcriptase catalytic subunit (TERT) by diclofenac and curcumin, alone and also in combination, in 1, 2-dimethylhydrazine dihydrochloride-induced colorectal cancer in rats. The relationship of telomerase activity with tumors suppressor proteins (p51, Rb, p21), cell cycle machinery, and apoptosis was also studied. Telomerase is highly expressed in DMH group and its high activity is associated with increased TERT expression. However, telomerase is absent or is present at lower levels in normal tissue. CDK4, CDK2, cyclin D1, and cyclin E are highly expressed in DMH as assessed by RT-PCR, qRT-PCR, Western blot, and immunofluorescence analysis. Diclofenac and curcumin overcome these carcinogenic effects by downregulating telomerase activity, diminishing the expression of TERT, CDK4, CDK2, cyclin D1, and cyclin E. The anticarcinogenic effects shown after the inhibition of telomerase activity by diclofenac and curcumin may be associated with upregulation of tumor suppressor proteins p51, Rb, and p21, whose activation induces the cells cycle arrest and apoptosis.

Isorhapontigenin (ISO) inhibited cell transformation by inducing G0/G1 phase arrest via increasing MKP-1 mRNA Stability.

PubMed

Gao, Guangxun; Chen, Liang; Li, Jingxia; Zhang, Dongyun; Fang, Yong; Huang, Haishan; Chen, Xiequn; Huang, Chuanshu

2014-05-15

The cancer chemopreventive property of Chinese herb new isolate isorhapontigenin (ISO) and mechanisms underlying its activity have never been explored. Here we demonstrated that ISO treatment with various concentrations for 3 weeks could dramatically inhibit TPA/EGF-induced cell transformation of Cl41 cells in Soft Agar assay, whereas co-incubation of cells with ISO at the same concentrations could elicit G0/G1 cell-cycle arrest without redundant cytotoxic effects on non-transformed cells. Further studies showed that ISO treatment resulted in cyclin D1 downregulation in dose- and time-dependent manner. Our results indicated that ISO regulated cyclin D1 at transcription level via targeting JNK/C-Jun/AP-1 activation. Moreover, we found that ISO-inhibited JNK/C-Jun/AP-1 activation was mediated by both upregulation of MKP-1 expression through increasing its mRNA stability and deactivating MKK7. Most importantly, MKP-1 knockdown could attenuate ISO-mediated suppression of JNK/C-Jun activation and cyclin D1 expression, as well as G0/G1 cell cycle arrest and cell transformation inhibition, while ectopic expression of FLAG-cyclin D1 T286A mutant also reversed ISO-induced G0/G1 cell-cycle arrest and inhibition of cell transformation. Our results demonstrated that ISO is a promising chemopreventive agent via upregulating mkp-1 mRNA stability, which is distinct from its cancer therapeutic effect with downregulation of XIAP and cyclin D1 expression.

NF-κB-dependent transcriptional upregulation of cyclin D1 exerts cytoprotection against hypoxic injury upon EGFR activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Zhi-Dong; Xu, Liang; Tang, Kan-Kai

Apoptosis of neural cells is one of the main pathological features in hypoxic/ischemic brain injury. Nuclear factor-κB (NF-κB) might be a potential therapeutic target for hypoxic/ischemic brain injury since NF-κB has been found to be inactivated after hypoxia exposure, yet the underlying molecular mechanisms of NF-κB inactivation are largely unknown. Here we report that epidermal growth factor receptor (EGFR) activation prevents neuron-like PC12 cells apoptosis in response to hypoxia via restoring NF-κB-dependent transcriptional upregulation of cyclin D1. Functionally, EGFR activation by EGF stimulation mitigates hypoxia-induced PC12 cells apoptosis in both dose- and time-dependent manner. Of note, EGFR activation elevates IKKβmore » phosphorylation, increases IκBα ubiquitination, promotes P65 nuclear translocation and recruitment at cyclin D1 gene promoter as well as upregulates cyclin D1 expression. EGFR activation also abrogates the decrease of IKKβ phosphorylation, reduction of IκBα ubiquitination, blockade of P65 nuclear translocation and recruitment at cyclin D1 gene promoter as well as downregulation of cyclin D1 expression induced by hypoxia. Furthermore, NF-κB-dependent upregulation of cyclin D1 is instrumental for the EGFR-mediated cytoprotection against hypoxic apoptosis. In addition, the dephosphorylation of EGFR induced by either EGF siRNA transfection or anti-HB-EGF neutralization antibody treatment enhances hypoxic cytotoxicity, which are attenuated by EGF administration. Our results highlight the essential role of NF-κB-dependent transcriptional upregulation of cyclin D1 in EGFR-mediated cytoprotective effects under hypoxic preconditioning and support further investigation of EGF in clinical trials of patients with hypoxic/ischemic brain injury. - Highlights: • EGFR activation significantly decreases hypoxia-induced PC12 cells injury. • EGFR activation abrogates the transcriptional repression of cyclin D1 induced by hypoxia in a NF-κB-dependent manner. • NF-κB-dependent cyclin D1 upregulation is required for the EGFR-mediated cytoprotection against hypoxia-induced injury. • Endogenous EGFR activity antagonizes hypoxia-induced PC12 cells injury.« less

Curcumin inhibits the proliferation and invasion of human osteosarcoma cell line MG-63 by regulating miR-138.

PubMed

Yu, Dazhi; An, Fengmei; He, Xu; Cao, Xuecheng

2015-01-01

In this study, we screened the different human osteosarcoma cell line MG-63 miRNAs after the treatment of curcumin and explored the effects of curcumin on MG-63 cells and its mechanism. Affemitrix miRNA chip was used to detect the changes of miRNA expression profile in MG-63 cells before and after curcumin treatment, and screen different expression of miRNAs. The target gene of miRNA was analyzed by bioinformatics. The expression levels of miRNA-138 target genes Smad4, NFκB p65 and cyclin D3 were detected. MTT and Transwell Cell invasion assays were used to observe the effects of curcumin on MG-63 cells. Curcumin could significantly inhibit the proliferation of MG-63 cells and the expression levels of miRNA-138 target genes Smad4, NFκB p65 and cyclin D3 in MG-63 cells (P<0.05); overexpression of hsa-miR-138 down-regulated the expression levels of Smad4, NFκB p65 and cyclin D3 compared with the treatment of curcumin, while inhibition of hsa-miR-138 up-regulated the expression levels of Smad4, NFκB p65 and cyclin D3. Curcumin could increase the expression of hsa-miR-138, hsa-miR-138 inhibited cell proliferation and invasive ability by inhibition of its target genes.

Neuron-derived orphan receptor 1 promoted human pulmonary artery smooth muscle cells proliferation.

PubMed

Wang, Chang-Guo; Lei, Wei; Li, Chang; Zeng, Da-Xiong; Huang, Jian-An

2015-05-01

As a transcription factor of the nuclear receptor superfamily, neuron-derived orphan receptor 1 (NOR1) is induced rapidly in response to various extracellular stimuli. But, it is still unclear its role in pulmonary artery smooth muscle cells proliferation. Human PASMCs were cultured in vitro and stimulated by serum. The special antisense oligodeoxynucleotides (AS-ODNs) were used to knockdown human NOR1 gene expression. Real-time PCR and Western-blot were used to evaluate the gene expression and protein levels. Fetal bovine serum (FBS) induced human PASMCs proliferation in a dose dependent manner. Furthermore, FBS promoted NOR1 gene expression in a dose dependent manner and a time dependent manner. 10% FBS induced a maximal NOR1 mRNA levels at 2 h. FBS also induced a significant higher NOR1 protein levels as compared with control. The NOR1 over-expressed plasmid significantly promoted DNA synthesis and cells proliferation. Moreover, the special AS-ODNs against human NOR1 not only prevented NOR1 expression but also inhibited DNA synthesis and cells proliferation significantly. The NOR1 over-expression plasmid could up-regulate cyclin D1 expression markedly, but the AS-ODNs inhibited cyclin D1 expression significantly. So, we concluded that NOR1 could promote human PASMCs proliferation. Cyclin D1 might be involved in this process.

Anti-inflammatory and anti-cancer activity of mulberry (Morus alba L.) root bark

PubMed Central

2014-01-01

Background Root bark of mulberry (Morus alba L.) has been used in herbal medicine as anti-phlogistic, liver protective, kidney protective, hypotensive, diuretic, anti-cough and analgesic agent. However, the anti-cancer activity and the potential anti-cancer mechanisms of mulberry root bark have not been elucidated. We performed in vitro study to investigate whether mulberry root bark extract (MRBE) shows anti-inflammatory and anti-cancer activity. Methods In anti-inflammatory activity, NO was measured using the griess method. iNOS and proteins regulating NF-κB and ERK1/2 signaling were analyzed by Western blot. In anti-cancer activity, cell growth was measured by MTT assay. Cleaved PARP, ATF3 and cyclin D1 were analyzed by Western blot. Results In anti-inflammatory effect, MRBE blocked NO production via suppressing iNOS over-expression in LPS-stimulated RAW264.7 cells. In addition, MRBE inhibited NF-κB activation through p65 nuclear translocation via blocking IκB-α degradation and ERK1/2 activation via its hyper-phosphorylation. In anti-cancer activity, MRBE deos-dependently induced cell growth arrest and apoptosis in human colorectal cancer cells, SW480. MRBE treatment to SW480 cells activated ATF3 expression and down-regulated cyclin D1 level. We also observed that MRBE-induced ATF3 expression was dependent on ROS and GSK3β. Moreover, MRBE-induced cyclin D1 down-regulation was mediated from cyclin D1 proteasomal degradation, which was dependent on ROS. Conclusions These findings suggest that mulberry root bark exerts anti-inflammatory and anti-cancer activity. PMID:24962785

Anti-inflammatory and anti-cancer activity of mulberry (Morus alba L.) root bark.

PubMed

Eo, Hyun Ji; Park, Jae Ho; Park, Gwang Hun; Lee, Man Hyo; Lee, Jeong Rak; Koo, Jin Suk; Jeong, Jin Boo

2014-06-25

Root bark of mulberry (Morus alba L.) has been used in herbal medicine as anti-phlogistic, liver protective, kidney protective, hypotensive, diuretic, anti-cough and analgesic agent. However, the anti-cancer activity and the potential anti-cancer mechanisms of mulberry root bark have not been elucidated. We performed in vitro study to investigate whether mulberry root bark extract (MRBE) shows anti-inflammatory and anti-cancer activity. In anti-inflammatory activity, NO was measured using the griess method. iNOS and proteins regulating NF-κB and ERK1/2 signaling were analyzed by Western blot. In anti-cancer activity, cell growth was measured by MTT assay. Cleaved PARP, ATF3 and cyclin D1 were analyzed by Western blot. In anti-inflammatory effect, MRBE blocked NO production via suppressing iNOS over-expression in LPS-stimulated RAW264.7 cells. In addition, MRBE inhibited NF-κB activation through p65 nuclear translocation via blocking IκB-α degradation and ERK1/2 activation via its hyper-phosphorylation. In anti-cancer activity, MRBE deos-dependently induced cell growth arrest and apoptosis in human colorectal cancer cells, SW480. MRBE treatment to SW480 cells activated ATF3 expression and down-regulated cyclin D1 level. We also observed that MRBE-induced ATF3 expression was dependent on ROS and GSK3β. Moreover, MRBE-induced cyclin D1 down-regulation was mediated from cyclin D1 proteasomal degradation, which was dependent on ROS. These findings suggest that mulberry root bark exerts anti-inflammatory and anti-cancer activity.

Effects of different starch source of starter on small intestinal growth and endogenous GLP-2 secretion in preweaned lambs.

PubMed

Sun, Daming; Li, Hongwei; Mao, Shengyong; Zhu, Weiyun; Liu, Junhua

2018-02-15

The objective of this study was to investigate the effects of different sources of starch in starter feed on small intestinal growth and endogenous glucagon-like peptide 2 (GLP-2) secretion in preweaned lambs. Twenty-four 10-d-old lambs were divided into three groups that were treated with different iso-starch diets containing purified cassava starch (CS, n = 8), maize starch (MS, n = 8), and pea starch (PS, n = 8). At 56 d old, there was no significant difference in final body weight (BW) of lambs among the three groups. However, different starch source in starter significantly affected the average daily feed intake (ADFI) and average daily gain (ADG) of lambs among three groups. Compared with the CS and MS diets, the PS diet significantly increased the GLP-2 concentration in blood plasma (P < 0.001), the crypt depth of the jejunum (P = 0.006), and the villus height of the ileum (P = 0.039). Meanwhile, PS diet significantly increased the mRNA expression of proglucagon and the glucagon-like peptide 2 receptor (GLP-2R) in the jejunum and ileum (P < 0.001). Furthermore, the PS diet significantly upregulated the mRNA expression of cyclin D1 (P < 0.001), cyclin E (P = 0.006), and cyclin-dependent kinases 6 (CDK6) (P = 0.048) in the jejunum and cyclin A (P < 0.001), cyclin D1 (P < 0.001), and CDK6 (P = 0.002) in the ileum. Correlation analysis showed that endogenous GLP-2 secretion was positively related to the mRNA levels of cell cycle proteins in small intestinal mucosa. In summary, all results showed that PS in starter feed promoted small intestinal growth that may, in part, be related to cell cycle acceleration and endogenous GLP-2 secretion in preweaned lambs. These findings provide new insights into nutritional interventions that promote the development of small intestines in young ruminants.

SMARCB1/INI1 inactivation in renal medullary carcinoma.

PubMed

Calderaro, Julien; Moroch, Julien; Pierron, Gaelle; Pedeutour, Florence; Grison, Camille; Maillé, Pascale; Soyeux, Pascale; de la Taille, Alexandre; Couturier, Jérome; Vieillefond, Annick; Rousselet, Marie Christine; Delattre, Olivier; Allory, Yves

2012-09-01

Renal medullary carcinoma (RMC), a rare and highly aggressive tumour which occurs in patients with sickle-cell disease, shares many clinicopathological features with collecting duct carcinoma (CDC). The molecular mechanisms underlying RMC and CDC are mainly unknown, and there is ongoing debate about their status as distinct entities. Loss of expression of SMARCB1/INI1, a chromatin remodelling regulator and repressor of cyclin D1 transcription, has been reported recently in RMC. The aim of our study was to investigate if such loss of expression is specific for RMC. SMARCB1/INI1 genetic alterations and cyclin D1 expression were also studied. Using immunochemistry, neoplastic cells showed complete loss of SMARCB1/INI1 expression in all six cases of RMC but in only one of 22 cases of CDC. In two RMC cases investigated, comparative genomic hybridization demonstrated complete loss of one SMARCB1/INI1 allele, with no other genomic imbalances, and no mutations were found on the remaining allele. Cyclin D1 was expressed in all RMCs, suggesting that SMARCB1/INI1 inactivation may result in increased cyclin D1 transcription. The specific SMARCB1/INI1 inactivation observed in RMCs suggests that RMC and CDC are different entities. © 2012 Blackwell Publishing Ltd.

miR-18a promotes cell proliferation of esophageal squamous cell carcinoma cells by increasing cylin D1 via regulating PTEN-PI3K-AKT-mTOR signaling axis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Weiguo, E-mail: weiguozhangHU@gmail.com; Lei, Caipeng; Fan, Junli

Esophageal squamous cell carcinoma (ESCC) is one of the lethal cancers with a high incidence rate in Asia. Cyclin D1 is overexpressed and plays an important role in the carcinogenesis of ESCC; however the mechanism of the deregulation of Cyclin D1 in ESCC remains to be determined. In the study, we found that miR-18a promotes the expression Cyclin D1 by targeting PTEN in eophageal squamous cell carcinoma TE13 and Eca109 cells. Transfection of miR-18a mimetics increased cyclin D1, while transfection of miR-18a antagomir decreased D1. Moreover, miR-18a-mediated upregulation of cyclin D1 was accompanied with downregulation of PTEN, which is a directmore » target of miR-18a, and increase of the phosphorylation of AKT and S6K1. In addition, pharmacologic inhibition of AKT or mTOR kinases abolished the increase of cyclinD1 by miR-18a, which was accompanied with decreased phosphorylation of Rb−S780 and inhibition of cell proliferation. Our results demonstrated the upregulation of miR-18a promoted cell proliferation by increasing cylin D1 via regulating PTEN-PI3K-AKT-mTOR signaling axis, suggesting that small molecule inhibitors of AKT-mTOR signaling are potential agents for the treatment of ESCC patients with upregulation of miR-17-92 cluster. - Highlights: • miR-18a promotes the proliferation of ESCC cells. • miR-18a increase cyclin D1 expression in ESCC cells. • miR-18a directly targets PTEN in ESCC cells. • Inhibition of AKT-mTOR prevents miR-18a-induced cyclin D1 in ESCC cells. • miR-18a antagomir sensitizes ESCC cells to cisplatin.« less

SALL2 represses cyclins D1 and E1 expression and restrains G1/S cell cycle transition and cancer-related phenotypes.

PubMed

E Hermosilla, Viviana; Salgado, Ginessa; Riffo, Elizabeth; Escobar, David; Hepp, Matías I; Farkas, Carlos; Galindo, Mario; Morín, Violeta; García-Robles, María A; Castro, Ariel F; Pincheira, Roxana

2018-04-24

SALL2 is a poorly characterized transcription factor that belongs to the Spalt-like family involved in development. Mutations on SALL2 have been associated with ocular coloboma and cancer. In cancers, SALL2 is deregulated and is proposed as a tumor suppressor in ovarian cancer. SALL2 has been implicated in stemness, cell death, proliferation, and quiescence. However, mechanisms underlying roles of SALL2 related to cancer remain largely unknown. Here, we investigated the role of SALL2 in cell proliferation using mouse embryo fibroblasts (MEFs) derived from Sall2 -/- mice. Compared to Sall2 +/+ MEFs, Sall2 -/- MEFs exhibit enhanced cell proliferation and faster postmitotic progression through G1 and S phases. Accordingly, Sall2 -/- MEFs exhibit higher mRNA and protein levels of cyclins D1 and E1. Chromatin immunoprecipitation and promoter reporter assays showed that SALL2 binds and represses CCND1 and CCNE1 promoters, identifying a novel mechanism by which SALL2 may control cell cycle. In addition, the analysis of tissues from Sall2 +/+ and Sall2 -/- mice confirmed the inverse correlation between expression of SALL2 and G1-S cyclins. Consistent with an antiproliferative function of SALL2, immortalized Sall2 -/- MEFs showed enhanced growth rate, foci formation, and anchorage-independent growth, confirming tumor suppressor properties for SALL2. Finally, cancer data analyses show negative correlations between SALL2 and G1-S cyclins' mRNA levels in several cancers. Altogether, our results demonstrated that SALL2 is a negative regulator of cell proliferation, an effect mediated in part by repression of G1-S cyclins' expression. Our results have implications for the understanding and significance of SALL2 role under physiological and pathological conditions. © 2018 The Authors. Published by FEBS Press and John Wiley & Sons Ltd.

The Kinetics of G2 and M Transitions Regulated by B Cyclins

PubMed Central

Huang, Yehong; Sramkoski, R. Michael; Jacobberger, James W.

2013-01-01

B cyclins regulate G2-M transition. Because human somatic cells continue to cycle after reduction of cyclin B1 (cycB1) or cyclin B2 (cycB2) by RNA interference (RNAi), and because cycB2 knockout mice are viable, the existence of two genes should be an optimization. To explore this idea, we generated HeLa BD™ Tet-Off cell lines with inducible cyclin B1- or B2-EGFP that were RNAi resistant. Cultures were treated with RNAi and/or doxycycline (Dox) and bromodeoxyuridine. We measured G2 and M transit times and 4C cell accumulation. In the absence of ectopic B cyclin expression, knockdown (kd) of either cyclin increased G2 transit. M transit was increased by cycB1 kd but decreased by cycB2 depletion. This novel difference was further supported by time-lapse microscopy. This suggests that cycB2 tunes mitotic timing, and we speculate that this is through regulation of a Golgi checkpoint. In the presence of endogenous cyclins, expression of active B cyclin-EGFPs did not affect G2 or M phase times. As previously shown, B cyclin co-depletion induced G2 arrest. Expression of either B cyclin-EGFP completely rescued knockdown of the respective endogenous cyclin in single kd experiments, and either cyclin-EGFP completely rescued endogenous cyclin co-depletion. Most of the rescue occurred at relatively low levels of exogenous cyclin expression. Therefore, cycB1 and cycB2 are interchangeable for ability to promote G2 and M transition in this experimental setting. Cyclin B1 is thought to be required for the mammalian somatic cell cycle, while cyclin B2 is thought to be dispensable. However, residual levels of cyclin B1 or cyclin B2 in double knockdown experiments are not sufficient to promote successful mitosis, yet residual levels are sufficient to promote mitosis in the presence of the dispensible cyclin B2. We discuss a simple model that would explain most data if cyclin B1 is necessary. PMID:24324638

Vitamin K2 alleviates type 2 diabetes in rats by induction of osteocalcin gene expression.

PubMed

Hussein, Atef G; Mohamed, Randa H; Shalaby, Sally M; Abd El Motteleb, Dalia M

2018-03-01

The biological mechanisms behind the association between vitamin K (Vit K) and glucose metabolism are uncertain. We aimed to analyze the expression of insulin 1 (Ins 1), insulin 2 (Ins 2) and cyclin D2, the expression of adiponectin and UCP-1 . In addition, we aimed to estimate the doses of Vit K2 able to affect various aspects of glucose and energy metabolism in type 2 diabetes. Thirty adult male rats were allocated equally into five groups: control group, diabetes mellitus group, and groups 3, 4, and 5, which received Vit K 2 at three daily dose levels (10, 15, and 30 mg/kg, respectively) for 8 wk. At the end of the study, blood samples were collected to quantify total osteocalcin, fasting plasma glucose, fasting insulin, and relevant variables. The expression of OC, Ins 1, Ins 2, cyclin D2, adiponectin, UCP-1 genes was analyzed by real-time polymerase chain reaction. After administration of Vit K 2 , a dose-dependent decrease in fasting plasma glucose, hemoglobin A1c and homeostatic model assessment method insulin resistance, and a dose-dependent increase in fasting insulin and homeostatic model assessment method β cell function levels, when compared with diabetes mellitus rats, were detected. There was significant upregulation of OC, Ins 1, Ins 2, or cyclin D2 gene expression in the three treated groups in a dose-dependent manner when compared with the diabetic rats. However, expression of adiponectin and UCP-1 were significantly increased at the highest dose (30 mg/kg daily) only. Vit K 2 administration could improve glycemic status in type 2 diabetic rats by induction of OC gene expression. Osteocalcin could increase β-cell proliferation, energy expenditure, and adiponectin expression. Different concentrations of Vit K 2 were required to affect glucose metabolism and insulin sensitivity. Copyright © 2017 Elsevier Inc. All rights reserved.

Role of Cyclin E as an Early Event in Ovarian Carcinogenesis

DTIC Science & Technology

2012-04-01

degradation . P27 is a powerful negative regulator of the cell cycle, preventing activation of cyclin E- cdk2 or cyclin D-cdk4 complexes and cell cycle...Ahmed M, Bavi P, et al. Bortezomib (Velcade) induces p27Kip1 expression through S-phase kinase protein 2 degradation in colorectal cancer. Cancer Res...CA1251CA72·4 CA 125 CA72-4 M-CSF CA 125/CA 72-4/M-CSFICA 15-3 CA125 CA 125/mesothelin CA 125/IL·6JIL·8NEGF;EGF CA 125/IL-6,G-CSFNEGF/EGF Leptin

The cyclin D1-CDK4 oncogenic interactome enables identification of potential novel oncogenes and clinical prognosis

PubMed Central

Jirawatnotai, Siwanon; Sharma, Samanta; Michowski, Wojciech; Suktitipat, Bhoom; Geng, Yan; Quackenbush, John; Elias, Joshua E; Gygi, Steven P; Wang, Yaoyu E; Sicinski, Piotr

2014-01-01

Overexpression of cyclin D1 and its catalytic partner, CDK4, is frequently seen in human cancers. We constructed cyclin D1 and CDK4 protein interaction network in a human breast cancer cell line MCF7, and identified novel CDK4 protein partners. Among CDK4 interactors we observed several proteins functioning in protein folding and in complex assembly. One of the novel partners of CDK4 is FKBP5, which we found to be required to maintain CDK4 levels in cancer cells. An integrative analysis of the extended cyclin D1 cancer interactome and somatic copy number alterations in human cancers identified BAIAPL21 as a potential novel human oncogene. We observed that in several human tumor types BAIAPL21 is expressed at higher levels as compared to normal tissue. Forced overexpression of BAIAPL21 augmented anchorage independent growth, increased colony formation by cancer cells and strongly enhanced the ability of cells to form tumors in vivo. Lastly, we derived an Aggregate Expression Score (AES), which quantifies the expression of all cyclin D1 interactors in a given tumor. We observed that AES has a prognostic value among patients with ER-positive breast cancers. These studies illustrate the utility of analyzing the interactomes of proteins involved in cancer to uncover potential oncogenes, or to allow better cancer prognosis. PMID:25486477

Ubiquitin specific protease 2 acts as a key modulator for the regulation of cell cycle by adiponectin and leptin in cancer cells.

PubMed

Nepal, Saroj; Shrestha, Anup; Park, Pil-Hoon

2015-09-05

Adiponectin and leptin, both produced from adipose tissue, cause cell cycle arrest and progression, respectively in cancer cells. Ubiquitin specific protease-2 (USP-2), a deubiquitinating enzyme, is known to impair proteasome-induced degradation of cyclin D1, a critical cell cycle regulator. Herein, we investigated the effects of these adipokines on USP-2 expression and its potential role in the modulation of cell cycle. Treatment with globular adiponectin (gAcrp) decreased, whereas leptin increased USP-2 expression both in human hepatoma and breast cancer cells. In addition, overexpression or gene silencing of USP-2 affected cyclin D1 expression and cell cycle progression/arrest by adipokines. Adiponectin and leptin also modulated in vitro proteasomal activity, which was partially dependent on USP-2 expression. Taken together, our results reveal that modulation of USP-2 expression plays a crucial role in cell cycle regulation by adipokines. Thus, USP-2 would be a promising therapeutic target for the modulation of cancer cell growth by adipokines. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The AhR is involved in the regulation of LoVo cell proliferation through cell cycle-associated proteins.

PubMed

Yin, Jiuheng; Sheng, Baifa; Han, Bin; Pu, Aimin; Yang, Kunqiu; Li, Ping; Wang, Qimeng; Xiao, Weidong; Yang, Hua

2016-05-01

Some ingredients in foods can activate the aryl hydrocarbon receptor (AhR) and arrest cell proliferation. In this study, we hypothesized that 6-formylindolo [3, 2-b] carbazole (FICZ) arrests the cell cycle in LoVo cells (a colon cancer line) through the AhR. The AhR agonist FICZ and the AhR antagonist CH223191 were used to treat LoVo cells. Real-time PCR and Western blot analyses were performed to detect the expression of the AhR, CYP1A1, CDK4, cyclinD1, cyclin E, CDK2, P27, and pRb. The distribution and activation of the AhR were detected with immunofluorescence. A 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and flow cytometric analysis were performed to measure cell viability, cell cycle stage, and apoptosis. Our results show that FICZ inhibited LoVo cell proliferation by inducing G1 cell cycle arrest but had no effect on epithelial apoptosis. Further analysis found that FICZ downregulated cyclinD1 and upregulated p27 expression to arrest Rb phosphorylation. The downregulation of cyclinD1 and upregulation of p27 were abolished by co-treatment with CH223191. We conclude that the AhR, when activated by FICZ (an endogenous AhR ligand), can arrest the cell cycle and block LoVo cell proliferation. © 2016 International Federation for Cell Biology.

Synchronous and Time-Dependent Expression of Cyclins, Cyclin-Dependant Kinases, and Apoptotic Genes in the Rumen Epithelia of Butyrate-Infused Goats

PubMed Central

Soomro, Jamila; Lu, Zhongyan; Gui, Hongbing; Zhang, Bei; Shen, Zanming

2018-01-01

In our previous study, we demonstrated that butyrate induced ruminal epithelial growth through cyclin D1 upregulation. Here, we investigated the influence of butyrate on the expression of genes associated with cell cycle and apoptosis in rumen epithelium. Goats (n = 24) were given an intra ruminal infusion of sodium butyrate at 0.3 (group B, n = 12) or 0 (group A, n = 12) g/kg of body weight (BW) per day before morning feeding for 28 days and were slaughtered (4 goat/group) at 5,7 and 9 h after butyrate infusion. Rumen fluid was analyzed for short chain fatty acids (SCFAs) concentration. Ruminal tissues were analyzed for morpho-histrometry and the expressions of genes associated with cell cycle and apoptosis. The results revealed that the ruminal butyrate concentration increased (P < 0.05) in B compared to group A. Morphometric analysis showed increased (P < 0.05) papillae size associated with higher number of cell layers in epithelial strata in B compared to A. Butyrate-induced papillae enlargement was coupled with enhanced mRNA expression levels (P < 0.05) of cyclin D1, CDK2, CDK4, and CDK6 (G0/G1 phase regulators) at 5 h, cyclin E1 (G1/S phase regulator) at 7 h and cyclin A and CDK1 (S phase regulators) at 9 h post-infusion compared to A group. In addition, the mRNA expression levels of apoptotic genes, i.e., caspase 3, caspase 9 and Bax at 5 h post-infusion were upregulated (P < 0.05) in group B compared to group A. The present study demonstrated that butyrate improved ruminal epithelial growth through concurrent and time-dependent changes in the expressions of genes involved in cell proliferation and apoptosis. It seems that the rate of proliferation was higher than the apoptosis which was reflected in epithelial growth. PMID:29875672

S6K1 is involved in polyploidization through its phosphorylation at Thr421/Ser424.

PubMed

Ma, Dongchu; Yu, Huiying; Lin, Di; Sun, Yinghui; Liu, Liping; Liu, Yage; Dai, Bing; Chen, Wei; Cao, Jianping

2009-04-01

Studies on polyploidization of megakaryocytes have been hampered by the lack of synchronized polyploid megakaryocytes. In this study, a relatively synchronized polyploid cell model was successfully established by employing Dami cells treated with nocodazole. In nocodazole-induced cells, cyclin B expression oscillated normally as in diploid cells and polyploid megakaryocytes. By using the nocodazole-induced Dami cell model, we found that 4E-BP1 and Thr421/Ser424 of ribosomal S6 kinase 1(S6K1) were phosphorylated mostly at M-phase in cytoplasm and oscillated in nocodazole-induced polyploid Dami cells, concomitant with increased expression of p27 and cyclin D3. However, phosphorylation of 4E-BP1 and S6K1 on Thr421/Ser424 was significantly decreased in differentiated Dami cells induced by phorbol 12-myristate 13-acetate (PMA), concomitant with increased expression of cyclin D1 and p21 and cyclin D3. Overexpression of the kinase dead form of S6K1 containing the mutation Lys 100 --> Gln in PMA-induced Dami cells increased ploidy whereas overexpression of rapamycin-resistant form of S6K1 containing the mutations Thr421 --> Glu and Ser424 --> Asp significantly dephosphorylated 4E-BP1 and reduced expression of cyclin D1, cyclin D3, p21 and p27, and slightly decreased the ploidy of PMA-induced Dami cells, compared with treatment with PMA alone. Moreover, overexpression of rapamycin-resistant form of S6K1 significantly reversed polyploidization of nocodazole-induced Dami cells. Furthermore, MAP (a novel compound synthesized recently) partly blocked the phosphorylation of S6K1 on Thr421/Ser424 and decreased the expression of p27 and polyploidization in nocodazole-induced Dami cells. Taken together, these data suggested that S6K1/4E-BP1 pathway may play an important role in polyploidization of megakaryocytes. (c) 2008 Wiley-Liss, Inc.

Overexpression of interleukin-2 receptor alpha in a human squamous cell carcinoma of the head and neck cell line is associated with increased proliferation, drug resistance, and transforming ability.

PubMed

Kuhn, Deborah J; Smith, David M; Pross, Seth; Whiteside, Theresa L; Dou, Q Ping

2003-07-01

It has been previously demonstrated that human carcinomas express interleukin-2 receptor (IL-2R) alpha, beta, and gamma chains. The beta and gamma chains of IL-2R have intermediate binding affinity for IL-2 and are responsible for the intracellular signaling cascades after IL-2 stimulation. IL-2Ralpha lacks the cytoplasmic domain, but is essential for increasing the IL-2-binding affinity of other receptors. Overexpression of IL-2Ralpha in tumor cells is associated with tumor progression and a poor patient prognosis. To define molecular mechanisms responsible for the effects associated with IL-2Ralpha expression, ex vivo experiments were performed with the squamous cell carcinoma head-and-neck cancer line, PCI-13, which was genetically engineered to overexpress the IL-2Ralpha chain. While IL-2Ralpha-overexpressing PCI-13 cells were capable of forming colonies in soft agar, PCI-13 cells transfected with the control vector or those expressing IL-2Rgamma did not. Consistently, IL-2Ralpha-expressing tumor cells proliferated more rapidly than the control or IL-2Rgamma+ cells, associated with increased levels of cyclins A and D1 and cyclin-dependent kinase (cdk(s)) 2 and 4 proteins. In addition, IL-2Ralpha-expressing cells were significantly more resistant to apoptosis induction by a tripeptidyl proteasome inhibitor (ALLN) and two chemotherapeutic drugs (VP-16 and taxol) than the control or IL-2Rgamma+ cells. Accompanying the drug resistance, high levels of anti-apoptotic Bcl-X(L) and Bcl-2 proteins were found in the mitochondria-containing fraction of IL-2Ralpha-expressing tumor cells. Treatment of IL-2Ralpha-expressing cells with a specific Janus kinase 3 (Jak3) inhibitor decreased expression of cyclin A, cyclin D1, Bcl-X(L), and Bcl-2 proteins. Finally, high levels of ubiquitinated proteins were detected in the proliferating IL-2Ralpha-expressing cells. Our data suggest that increased proliferation rates and decreased drug sensitivity of IL-2Ralpha-expressing tumor cells are responsible for the enhanced tumor aggressiveness and poor clinical prognosis of patients whose tumors express IL-2Ralpha. Copyright 2003 Wiley-Liss, Inc.

CDC25B and p53 are independently implicated in radiation sensitivity for human esophageal cancers.

PubMed

Miyata, H; Doki, Y; Shiozaki, H; Inoue, M; Yano, M; Fujiwara, Y; Yamamoto, H; Nishioka, K; Kishi, K; Monden, M

2000-12-01

Ionized radiation leads to G1 arrest and apoptosis by a p53-dependent pathway and G2-M arrest through a p53-independent pathway. In this study, we evaluated the role of cell cycle-regulating molecules in the sensitivity of cancer cells for radiation therapy. Forty-seven patients with squamous cell carcinomas of the esophagus had undergone radiation therapy, followed by surgical resection. They were classified as sensitive to radiation (SR, 14 cases) with no residual tumor in the surgical specimen or as resistant to radiation (RR, 33 cases) with viable residual tumors. Their preradiation biopsy samples were immunohistochemically investigated for the expressions of cell cycle-related molecules, including p53, CDC25A, CDC25B, cyclin D1, cyclin B1, and Ki-67. p53 expression was negative in 71% (10 of 14) of SR and positive in 91% (30 of 33) of RR. The association was strong between high radiation sensitivity and negative p53 expression (P < 0.0001). CDC25B, which is not expressed in normal epithelium but is in the cytoplasm of esophageal cancers, was strongly expressed (2+) in 46% (6 of 14) of SR and in 6% (2 of 23) of RR. Thus, the sensitivity for radiation therapy was significantly correlated with CDC25B overexpression. With respect to CDC25A, cyclin D1, cyclin B1, and Ki-67, no statistically significant differences were found in their expressions between SR and RR tumors. p53 and CDC25B expressions showed no significant associations, and multivariate analysis revealed that both p53 and CDC25B are significant independent markers for predicting radiation sensitivity. CDC25B was revealed to be a novel predictor of radiation sensitivity in esophageal cancers. Because CDC25B is an oncogene, which affects G2-M progression, these results suggest the importance of a p53-independent G2-M checkpoint in radiation therapy.

Cooperation of p27Kip1 and p18INK4c in Progestin-Mediated Cell Cycle Arrest in T-47D Breast Cancer Cells

PubMed Central

Swarbrick, Alexander; Lee, Christine S. L.; Sutherland, Robert L.; Musgrove, Elizabeth A.

2000-01-01

The steroid hormone progesterone regulates proliferation and differentiation in the mammary gland and uterus by cell cycle phase-specific actions. The long-term effect of progestins on T-47D breast cancer cells is inhibition of cellular proliferation. This is accompanied by decreased G1 cyclin-dependent kinase (CDK) activities, redistribution of the CDK inhibitor p27Kip1 among these CDK complexes, and alterations in the elution profile of cyclin E-Cdk2 upon gel filtration chromatography, such that high-molecular-weight complexes predominate. This study aimed to determine the relative contribution of CDK inhibitors to these events. Following progestin treatment, the majority of cyclin E- and D-CDK complexes were bound to p27Kip1 and few were bound to p21Cip1. In vitro, recombinant His6-p27 could quantitatively reproduce the effects on cyclin E-Cdk2 kinase activity and the shift in molecular weight observed following progestin treatment. In contrast, cyclin D-Cdk4 was not inhibited by His6-p27 in vitro or p27Kip1 in vivo. However, an increase in the expression of the Cdk4/6 inhibitor p18INK4c and its extensive association with Cdk4 and Cdk6 were apparent following progestin treatment. Recombinant p18INK4c led to the reassortment of cyclin-CDK-CDK inhibitor complexes in vitro, with consequent decrease in cyclin E-Cdk2 activity. These results suggest a concerted model of progestin action whereby p27Kip1 and p18INK4c cooperate to inhibit cyclin E-Cdk2 and Cdk4. Since similar models have been developed for growth inhibition by transforming growth factor β and during adipogenesis, interaction between the Cip/Kip and INK4 families of inhibitors may be a common theme in physiological growth arrest and differentiation. PMID:10713180

Obatoclax, a Pan-BCL-2 Inhibitor, Targets Cyclin D1 for Degradation to Induce Antiproliferation in Human Colorectal Carcinoma Cells.

PubMed

Or, Chi-Hung R; Chang, Yachu; Lin, Wei-Cheng; Lee, Wee-Chyan; Su, Hong-Lin; Cheung, Muk-Wing; Huang, Chang-Po; Ho, Cheesang; Chang, Chia-Che

2016-12-27

Colorectal cancer is the third most common cancer worldwide. Aberrant overexpression of antiapoptotic BCL-2 (B-cell lymphoma 2) family proteins is closely linked to tumorigenesis and poor prognosis in colorectal cancer. Obatoclax is an inhibitor targeting all antiapoptotic BCL-2 proteins. A previous study has described the antiproliferative action of obatoclax in one human colorectal cancer cell line without elucidating the underlying mechanisms. We herein reported that, in a panel of human colorectal cancer cell lines, obatoclax inhibits cell proliferation, suppresses clonogenicity, and induces G₁-phase cell cycle arrest, along with cyclin D1 downregulation. Notably, ectopic cyclin D1 overexpression abrogated clonogenicity suppression but also G₁-phase arrest elicited by obatoclax. Mechanistically, pre-treatment with the proteasome inhibitor MG-132 restored cyclin D1 levels in all obatoclax-treated cell lines. Cycloheximide chase analyses further revealed an evident reduction in the half-life of cyclin D1 protein by obatoclax, confirming that obatoclax downregulates cyclin D1 through induction of cyclin D1 proteasomal degradation. Lastly, threonine 286 phosphorylation of cyclin D1, which is essential for initiating cyclin D1 proteasomal degradation, was induced by obatoclax in one cell line but not others. Collectively, we reveal a novel anticancer mechanism of obatoclax by validating that obatoclax targets cyclin D1 for proteasomal degradation to downregulate cyclin D1 for inducing antiproliferation.

Suppression of Akt-mediated HDAC3 expression and CDK2 T39 phosphorylation by a bichalcone analog contributes to S phase retardation of cancer cells.

PubMed

Hung, Kuang-Chen; Lin, Meng-Liang; Hsu, Shih-Wei; Lee, Chuan-Chun; Huang, Ren-Yu; Wu, Tian-Shung; Chen, Shih-Shun

2018-06-15

Targeting cell cycle regulators has been a suggested mechanism for therapeutic cancer strategies. We report here that the bichalcone analog TSWU-CD4 induces S phase arrest of human cancer cells by inhibiting the formation of cyclin A-phospho (p)-cyclin-dependent kinase 2 (CDK2, threonine [Thr] 39) complexes, independent of mutant p53 expression. Ectopic expression of CDK2 (T39E), which mimics phosphorylation of the Thr 39 residue of CDK2, partially rescues the cells from TSWU-CD4-induced S phase arrest, whereas phosphorylation-deficient CDK2 (T39A) expression regulates cell growth with significant S phase arrest and enhances TSWU-CD4-triggered S phase arrest. Decreased histone deacetylase 3 (HDAC3) expression after TSWU-CD4 treatment was demonstrated, and TSWU-CD4 induced S phase arrest and inhibitory effects on cyclin A expression and CDK2 Thr 39 phosphorylation, while cyclin A-p-CDK2 (Thr 39) complex formation was suppressed by ectopic wild-type HDAC3 expression. The co-transfection of CDK2 (T39E) along with HDAC3 completely restored cyclin A expression, Thr 39-phosphorylated CDK2, cyclin A-p-CDK2 (Thr 39) complex formation, and the S phase population to normal levels. Protein kinase B (Akt) inactivation was required for TSWU-CD4-induced S phase cell cycle arrest, because constitutively active Akt1 blocks the induction of S phase arrest and the suppression of cyclin A and HDAC3 expression, CDK2 Thr 39 phosphorylation, and cyclin A-p-CDK2 (Thr 39) complex formation by TSWU-CD4. Taken together, our results indicate that TSWU-CD4 induces S phase arrest by inhibiting Akt-mediated HDAC3 expression and CDK2 Thr 39 phosphorylation to suppress the formation of cyclin A-p-CDK2 (Thr 39) complexes. Copyright © 2018 Elsevier B.V. All rights reserved.

Persistence of RSV promotes proliferation and epithelial-mesenchymal transition of bronchial epithelial cells through Nodal signaling.

PubMed

Xiang, Zhao; Liang, Zhang; Yanfeng, Huang; Leitao, Kang

2017-10-01

Nodal may play an important role in the development of cancers. The present study was designed to determine the effects of Nodal induced by respiratory syncytial virus (RSV) infection on the occurrence and development of lung cancer and the underlying mechanisms. After verification of RSV infection by observation of cytopathic effect and indirect immunofluorescence, real-time PCR, Western blot and methylation assays were used to verify the influence of RSV on Nodal expression. Then, a Nodal overexpressed vector was constructed and the effects of Nodal on the proliferation and apoptosis of bronchial epithelial cells (BECs) and epithelial-mesenchymal transition (EMT) were assayed by flow cytometry and Western blot, respectively. Moreover, Lefty and pSmad2/3 were assayed by Western blot and Cyclin D1, CDK4, c-myc and Bcl-2 induced by Nodal overepression or RSV infection were also assayed by real-time PCR. The results showed that Nodal over expression and demethylation of the promoter were observed in BECs after RSV infection. Activation of Nodal promoted proliferation, colony formation and EMT and inhibited apoptosis of BECs. Nodal also promoted malignant change by promoting expression of cyclin D1 and related-dependent kinase and inhibiting apoptosis. Besides, RSV infection inhibited Lefty expression and promoted the activation of pSmad2/3. RSV also promoted Cyclin D1, CDK4, c-myc and Bcl-2 expression through the activation of pSmad2/3. Our data showed that persistence of RSV promoted the proliferation, epithelial-mesenchymal transition and expression of oncogenes through Nodal signaling, which may be associated with the occurrence and development of lung cancers.

Oxygen-Glucose Deprivation Induces G2/M Cell Cycle Arrest in Brain Pericytes Associated with ERK Inactivation.

PubMed

Wei, Wenjie; Yu, Zhiyuan; Xie, Minjie; Wang, Wei; Luo, Xiang

2017-01-01

Growing evidence has revealed that brain pericytes are multifunctional and contribute to the pathogenesis of a number of neurological disorders. However, the role of pericytes in cerebral ischemia, and especially the pathophysiological alterations in pericytes, remains unclear. In the present study, our aim was to determine whether the proliferation of pericytes is affected by cerebral ischemia and, if so, to identify the underlying mechanism(s). Cultured brain pericytes subjected to oxygen-glucose deprivation (OGD) were used as our model of cerebral ischemia; the protein expression levels of cyclin D1, cyclin E, cdk4, and cyclin B1 were determined by Western blot analysis, and cell cycle analysis was assessed by flow cytometry. The OGD treatment reduced the brain pericyte proliferation by causing G2/M phase arrest and downregulating the protein levels of cyclin D1, cyclin E, cdk4, and cyclin B1. Further studies demonstrated a simultaneous decrease in the activity of extracellular regulated protein kinases (ERK), suggesting a critical role of the ERK signaling cascade in the inhibition of OGD-induced pericyte proliferation. We suggest that OGD inhibition of the proliferation of brain pericytes is associated with the inactivation of the ERK signaling pathway, which arrests them in the G2/M phase.

Curcumin inhibits the proliferation and invasion of human osteosarcoma cell line MG-63 by regulating miR-138

PubMed Central

Yu, Dazhi; An, Fengmei; He, Xu; Cao, Xuecheng

2015-01-01

Objective: In this study, we screened the different human osteosarcoma cell line MG-63 miRNAs after the treatment of curcumin and explored the effects of curcumin on MG-63 cells and its mechanism. Methods: Affemitrix miRNA chip was used to detect the changes of miRNA expression profile in MG-63 cells before and after curcumin treatment, and screen different expression of miRNAs. The target gene of miRNA was analyzed by bioinformatics. The expression levels of miRNA-138 target genes Smad4, NFκB p65 and cyclin D3 were detected. MTT and Transwell Cell invasion assays were used to observe the effects of curcumin on MG-63 cells. Results: Curcumin could significantly inhibit the proliferation of MG-63 cells and the expression levels of miRNA-138 target genes Smad4, NFκB p65 and cyclin D3 in MG-63 cells (P<0.05); overexpression of hsa-miR-138 down-regulated the expression levels of Smad4, NFκB p65 and cyclin D3 compared with the treatment of curcumin, while inhibition of hsa-miR-138 up-regulated the expression levels of Smad4, NFκB p65 and cyclin D3. Conclusions: Curcumin could increase the expression of hsa-miR-138, hsa-miR-138 inhibited cell proliferation and invasive ability by inhibition of its target genes. PMID:26823826

Epigenetic regulation of vascular smooth muscle cell proliferation and neointima formation by histone deacetylase inhibition.

PubMed

Findeisen, Hannes M; Gizard, Florence; Zhao, Yue; Qing, Hua; Heywood, Elizabeth B; Jones, Karrie L; Cohn, Dianne; Bruemmer, Dennis

2011-04-01

Proliferation of smooth muscle cells (SMC) in response to vascular injury is central to neointimal vascular remodeling. There is accumulating evidence that histone acetylation constitutes a major epigenetic modification for the transcriptional control of proliferative gene expression; however, the physiological role of histone acetylation for proliferative vascular disease remains elusive. In the present study, we investigated the role of histone deacetylase (HDAC) inhibition in SMC proliferation and neointimal remodeling. We demonstrate that mitogens induce transcription of HDAC 1, 2, and 3 in SMC. Short interfering RNA-mediated knockdown of either HDAC 1, 2, or 3 and pharmacological inhibition of HDAC prevented mitogen-induced SMC proliferation. The mechanisms underlying this reduction of SMC proliferation by HDAC inhibition involve a growth arrest in the G(1) phase of the cell cycle that is due to an inhibition of retinoblastoma protein phosphorylation. HDAC inhibition resulted in a transcriptional and posttranscriptional regulation of the cyclin-dependent kinase inhibitors p21(Cip1) and p27(Kip). Furthermore, HDAC inhibition repressed mitogen-induced cyclin D1 mRNA expression and cyclin D1 promoter activity. As a result of this differential cell cycle-regulatory gene expression by HDAC inhibition, the retinoblastoma protein retains a transcriptional repression of its downstream target genes required for S phase entry. Finally, we provide evidence that these observations are applicable in vivo by demonstrating that HDAC inhibition decreased neointima formation and expression of cyclin D1 in a murine model of vascular injury. These findings identify HDAC as a critical component of a transcriptional cascade regulating SMC proliferation and suggest that HDAC might play a pivotal role in the development of proliferative vascular diseases, including atherosclerosis and in-stent restenosis.

Epigenetic Regulation of Vascular Smooth Muscle Cell Proliferation and Neointima Formation by Histone Deacetylase Inhibition

PubMed Central

Findeisen, Hannes M.; Gizard, Florence; Zhao, Yue; Qing, Hua; Heywood, Elizabeth B.; Jones, Karrie L.; Cohn, Dianne; Bruemmer, Dennis

2011-01-01

Objective Proliferation of smooth muscle cells (SMC) in response to vascular injury is central to neointimal vascular remodeling. There is accumulating evidence that histone acetylation constitutes a major epigenetic modification for the transcriptional control of proliferative gene expression; however, the physiological role of histone acetylation for proliferative vascular disease remains elusive. Methods and Results In the present study, we investigated the role of histone deacetylase (HDAC) inhibition in SMC proliferation and neointimal remodeling. We demonstrate that mitogens induce transcription of HDAC 1, 2 and 3 in SMC. siRNA-mediated knock-down of either HDAC 1, 2 or 3 and pharmacologic inhibition of HDAC prevented mitogen-induced SMC proliferation. The mechanisms underlying this reduction of SMC proliferation by HDAC inhibition involve a growth arrest in the G1-phase of the cell cycle due to an inhibition of retinoblastoma protein phosphorylation. HDAC inhibition resulted in a transcriptional and posttranscriptional regulation of the cyclin-dependent kinase inhibitors p21Cip1 and p27Kip. Furthermore, HDAC inhibition repressed mitogen-induced cyclin D1 mRNA expression and cyclin D1 promoter activity. As a result of this differential cell cycle-regulatory gene expression by HDAC inhibition, the retinoblastoma protein retains a transcriptional repression of its downstream target genes required for S phase entry. Finally, we provide evidence that these observations are applicable in vivo by demonstrating that HDAC inhibition decreased neointima formation and expression of cyclin D1 in a murine model of vascular injury. Conclusion These findings identify HDAC as a critical component of a transcriptional cascade regulating SMC proliferation and suggest that HDAC might play a pivotal role in the development of proliferative vascular diseases, including atherosclerosis and in-stent restenosis. PMID:21233448

MicroRNA let-7b regulates neural stem cell proliferation and differentiation by targeting nuclear receptor TLX signaling

PubMed Central

Zhao, Chunnian; Sun, GuoQiang; Li, Shengxiu; Lang, Ming-Fei; Yang, Su; Li, Wendong; Shi, Yanhong

2010-01-01

Neural stem cell self-renewal and differentiation is orchestrated by precise control of gene expression involving nuclear receptor TLX. Let-7b, a member of the let-7 microRNA family, is expressed in mammalian brains and exhibits increased expression during neural differentiation. However, the role of let-7b in neural stem cell proliferation and differentiation remains unknown. Here we show that let-7b regulates neural stem cell proliferation and differentiation by targeting the stem cell regulator TLX and the cell cycle regulator cyclin D1. Overexpression of let-7b led to reduced neural stem cell proliferation and increased neural differentiation, whereas antisense knockdown of let-7b resulted in enhanced proliferation of neural stem cells. Moreover, in utero electroporation of let-7b to embryonic mouse brains led to reduced cell cycle progression in neural stem cells. Introducing an expression vector of Tlx or cyclin D1 that lacks the let-7b recognition site rescued let-7b-induced proliferation deficiency, suggesting that both TLX and cyclin D1 are important targets for let-7b-mediated regulation of neural stem cell proliferation. Let-7b, by targeting TLX and cyclin D1, establishes an efficient strategy to control neural stem cell proliferation and differentiation. PMID:20133835

MicroRNA let-7b regulates neural stem cell proliferation and differentiation by targeting nuclear receptor TLX signaling.

PubMed

Zhao, Chunnian; Sun, GuoQiang; Li, Shengxiu; Lang, Ming-Fei; Yang, Su; Li, Wendong; Shi, Yanhong

2010-02-02

Neural stem cell self-renewal and differentiation is orchestrated by precise control of gene expression involving nuclear receptor TLX. Let-7b, a member of the let-7 microRNA family, is expressed in mammalian brains and exhibits increased expression during neural differentiation. However, the role of let-7b in neural stem cell proliferation and differentiation remains unknown. Here we show that let-7b regulates neural stem cell proliferation and differentiation by targeting the stem cell regulator TLX and the cell cycle regulator cyclin D1. Overexpression of let-7b led to reduced neural stem cell proliferation and increased neural differentiation, whereas antisense knockdown of let-7b resulted in enhanced proliferation of neural stem cells. Moreover, in utero electroporation of let-7b to embryonic mouse brains led to reduced cell cycle progression in neural stem cells. Introducing an expression vector of Tlx or cyclin D1 that lacks the let-7b recognition site rescued let-7b-induced proliferation deficiency, suggesting that both TLX and cyclin D1 are important targets for let-7b-mediated regulation of neural stem cell proliferation. Let-7b, by targeting TLX and cyclin D1, establishes an efficient strategy to control neural stem cell proliferation and differentiation.

c-Jun/AP-1 pathway-mediated cyclin D1 expression participates in low dose arsenite-induced transformation in mouse epidermal JB6 Cl41 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Dongyun; Li Jingxia; Gao Jimin

2009-02-15

Arsenic is a well-documented human carcinogen associated with skin carcinogenesis. Our previous work reveals that arsenite exposure is able to induce cell transformation in mouse epidermal cell JB6 Cl41 through the activation of ERK, rather than JNK pathway. Our current studies further evaluate downstream pathway in low dose arsenite-induced cell transformation in JB6 Cl41 cells. Our results showed that treatment of cells with low dose arsenite induced activation of c-Jun/AP-1 pathway, and ectopic expression of dominant negative mutant of c-Jun (TAM67) blocked arsenite-induced transformation. Furthermore, our data indicated that cyclin D1 was an important downstream molecule involved in c-Jun/AP-1-mediated cellmore » transformation upon low dose arsenite exposure, because inhibition of cyclin D1 expression by its specific siRNA in the JB6 Cl41 cells resulted in impairment of anchorage-independent growth of cells induced by low dose arsenite. Collectively, our results demonstrate that c-Jun/AP-1-mediated cyclin D1 expression is at least one of the key events implicated in cell transformation upon low dose arsenite exposure.« less

LSD1 sustains estrogen-driven endometrial carcinoma cell proliferation through the PI3K/AKT pathway via di-demethylating H3K9 of cyclin D1.

PubMed

Chen, Chunqin; Wang, Yanan; Wang, Shiyu; Liu, Yuan; Zhang, Jiawen; Xu, Yuyao; Zhang, Zhenbo; Bao, Wei; Wu, Sufang

2017-03-01

A recent study reported that histone lysine specific demethylase 1 (LSD1, KDM1A) is overexpressed in endometrioid endometrial carcinoma (EEC) and associated with tumor progression as well as poor prognosis. However, the physiological function and mechanism of LSD1 in endometrial cancer (EC) remains largely unknown. In this study, we demonstrate that β-estradiol (E2) treatment increased LSD1 expression via the GPR30/PI3K/AKT pathway in endometrial cancer cells. Both siGPR30 and the PI3K inhibitor LY294002 block this effect. RNAi-mediated silencing of LSD1 abolished estrogen-driven endometrial cancer cell (ECC) proliferation, and induced G1 cell arrest and apoptosis. Mechanistically, we find that LSD1 silencing results in PI3K/AKT signal inactivation, but without the elevation of PTEN expression as expected. This is because the inhibition of LSD1 induces dimethylation of lysine 9 on histone H3 (H3K9m2) accumulation at the promoter region of cyclin D1. Interfering with cyclin D1 leads to PI3K/AKT signal suppression. Re-overexpression of cyclin D1 in LSD1-knockdown ECCs reverses the LSD1 inhibitory action. Our finding connects estrogen signaling with epigenetic regulation in EEC and provides novel experimental support for LSD1 as a potential target for endometrial cancer therapeutics.

Suppressive effects of 3-bromopyruvate on the proliferation and the motility of hepatocellular carcinoma cells.

PubMed

Tomizawa, Minoru; Shinozaki, Fuminobu; Motoyoshi, Yasufumi; Sugiyama, Takao; Yamamoto, Shigenori; Ishige, Naoki

2016-01-01

The compound 3-bromopyruvate (3BP) is an analogue of pyruvate, which is the final product of glycolysis that enters the citric acid cycle. The present study aimed to investigate the suppressive effects of 3BP on the proliferation and motility of hepatocellular carcinoma (HCC) cells. HLF and PLC/PRF/5 cells were cultured with 3BP and subjected to an MTS assay. Apoptosis was analyzed by hematoxylin and eosin staining. Cell motility was analyzed using a scratch assay. Real-time quantitative polymerase chain reaction (PCR) was performed to determine the expression levels of cyclin D1 and matrix metalloproteinase (MMP)9. Proliferation of both cell lines was significantly suppressed by 3BP at 100 µM (P<0.05). The expression level of cyclin D1 was decreased after 3BP treatment at 100 µM in both cell lines (P<0.05). Pyknotic nuclei were observed in the cells cultured with 3BP at 100 µM. These results revealed that 3BP suppressed cell proliferation, decreased the expression of cyclin D1, and induced apoptosis in HCC cells. 3BP significantly suppressed motility in both cell lines (P<0.05). The expression level of MMP9 was significantly decreased (P<0.05). 3BP suppressed the proliferation and motility of HCC cells by decreasing the expression of cyclin D1 and MMP9.

The cytoplasmic expression of MUC1 in papillary thyroid carcinoma of different histological variants and its correlation with cyclin D1 overexpression.

PubMed

Abrosimov, Alexander; Saenko, Vladimir; Meirmanov, Serik; Nakashima, Masahiro; Rogounovitch, Tatiana; Shkurko, Olesya; Lushnikov, Eugeny; Mitsutake, Norisato; Namba, Hiroyuki; Yamashita, Shunichi

2007-01-01

This study addressed the immunohistochemical expression of MUC1 in papillary thyroid carcinoma (PTC) of different histotypes, sizes, and morphological features of aggressiveness, and its correlation with the overexpression of cyclin D1, a target molecule of the Wnt pathway. MUC1 expression was examined in a total of 209 PTCs. Cytoplasmic MUC1 expression was elevated in the tall, columnar cell and oncocytic variants (100%), Warthin-like (78%), and conventional PTCs (61%), and in papillary microcarcinoma (PMC) with the conventional growth pattern (52%). On the contrary, it was low in the follicular variant (27%) of PTC and PMCs with follicular architecture (13%). Cytoplasmic MUC1 accumulation did not associate with any clinicopathological features except peritumoral lymphoid infiltration in PTCs and in PMCs with the conventional growth pattern. MUC1 staining correlated with cyclin D1 overexpression in conventional PTCs and PMCs and PMCs with follicular architecture. The results demonstrate that MUC1 expression varies broadly in different histological variants of PTC, being the lowest in tumors with follicular structure. In general, it does not prove to be a prognosticator of PTC aggressiveness. A high correlation between MUC1 and cyclin D1 implies MUC1 involvement in the Wnt cascade functioning in a large subset of human PTCs and PMCs.

Down-regulation of NTCP expression by cyclin D1 in hepatitis B virus-related hepatocellular carcinoma has clinical significance

PubMed Central

Kang, Jingting; Wang, Jie; Cheng, Jin; Cao, Zhiliang; Chen, Ran; Li, Huiyu; Liu, Shuang; Chen, Xiangmei; Sui, Jianhua; Lu, Fengmin

2017-01-01

The sodium-dependent taurocholate cotransporter polypeptide (NTCP) has been identified as a liver specific functional receptor for the hepatitis B virus (HBV). Previous studies indicated that the expression of NTCP may be associated with the proliferation status of hepatocytes. However, the involvement of NTCP in hepatocellular carcinoma (HCC) cells proliferation remains unclear. In this study, we confirmed that NTCP was down-regulated in HCC tumor tissues compared with that in the adjacent non-tumor tissues (P < 0.0001). Clinically, lower expression of NTCP was correlated with poor post-surgery survival rate (P = 0.0009) and larger tumor tissue mass (P = 0.003) of HCC patients. This was supported by the finding that ectopic expression of NTCP in both HepG2 and Huh-7 cells could significantly suppress hepatocytes growth by arresting cells in G0/G1 phase. We also discovered that cyclin D1 could transcriptionally suppress NTCP expression by inhibiting the activity of NTCP promoter, while arresting HCC cells in G0/G1 phase by serum starvation could upregulate NTCP mRNA levels. This is the first study to report that the transcriptional inhibition of NTCP expression during cell cycle progression was mediated by cyclin D1. The down-regulated NTCP expression was associated with poor prognosis and lower HBV cccDNA level in HCC patients. Therefore, NTCP expression levels might serve as a novel prognostic predictive marker for post-surgery survival rate of HCC patients. PMID:28915572

Down-regulation of NTCP expression by cyclin D1 in hepatitis B virus-related hepatocellular carcinoma has clinical significance.

PubMed

Kang, Jingting; Wang, Jie; Cheng, Jin; Cao, Zhiliang; Chen, Ran; Li, Huiyu; Liu, Shuang; Chen, Xiangmei; Sui, Jianhua; Lu, Fengmin

2017-08-22

The sodium-dependent taurocholate cotransporter polypeptide (NTCP) has been identified as a liver specific functional receptor for the hepatitis B virus (HBV). Previous studies indicated that the expression of NTCP may be associated with the proliferation status of hepatocytes. However, the involvement of NTCP in hepatocellular carcinoma (HCC) cells proliferation remains unclear. In this study, we confirmed that NTCP was down-regulated in HCC tumor tissues compared with that in the adjacent non-tumor tissues ( P < 0.0001). Clinically, lower expression of NTCP was correlated with poor post-surgery survival rate ( P = 0.0009) and larger tumor tissue mass ( P = 0.003) of HCC patients. This was supported by the finding that ectopic expression of NTCP in both HepG2 and Huh-7 cells could significantly suppress hepatocytes growth by arresting cells in G0/G1 phase. We also discovered that cyclin D1 could transcriptionally suppress NTCP expression by inhibiting the activity of NTCP promoter, while arresting HCC cells in G0/G1 phase by serum starvation could upregulate NTCP mRNA levels. This is the first study to report that the transcriptional inhibition of NTCP expression during cell cycle progression was mediated by cyclin D1. The down-regulated NTCP expression was associated with poor prognosis and lower HBV cccDNA level in HCC patients. Therefore, NTCP expression levels might serve as a novel prognostic predictive marker for post-surgery survival rate of HCC patients.

Establishment of an immortalized cell line derived from the prairie vole via lentivirus-mediated transduction of mutant cyclin-dependent kinase 4, cyclin D, and telomerase reverse transcriptase

PubMed Central

Katayama, Masafumi; Kiyono, Tohru; Horie, Kengo; Hirayama, Takashi; Eitsuka, Takahiro; Kuroda, Kengo; Donai, Kenichiro; Hidema, Shizu; Nishimori, Katsuhiko; Fukuda, Tomokazu

2015-01-01

The prairie vole (Microtus ochrogaster) shows social behaviors such as monogamy and parenting of infants with pair bonding. These social behaviors are specific to the prairie vole and have not been observed in other types of voles, such as mountain voles. Although the prairie vole has several unique characteristics, an in vitro cell culture system has not been established for this species. Furthermore, establishment of cultured cells derived from the prairie vole may be beneficial based on the three Rs (i.e., Replacement, Reduction, and Refinement) concept. Therefore, in this study, we attempted to establish an immortalized cell line derived from the prairie vole. Our previous research has shown that transduction with mutant forms of cyclin-dependent kinase 4 (CDK4), cyclin D, and telomerase reverse transcriptase (TERT) could efficiently immortalize cells from multiple species, including humans, cattle, pigs, and monkeys. Here, we introduced these three genes into prairie vole-derived muscle fibroblasts. The expression of mutant CDK4 and cyclin D proteins was confirmed by western blotting, and telomerase activity was detected in immortalized vole muscle-derived fibroblasts (VMF-K4DT cells or VMFs) by stretch PCR. Population doubling analysis showed that the introduction of mutant CDK4, cyclin D, and TERT extended the lifespan of VMFs. To the best of our knowledge, this is the first report describing the establishment of an immortalized cell line derived from the prairie vole through the expression of mutant CDK4, cyclin D, and human TERT. PMID:26496927

Establishment of an immortalized cell line derived from the prairie vole via lentivirus-mediated transduction of mutant cyclin-dependent kinase 4, cyclin D, and telomerase reverse transcriptase.

PubMed

Katayama, Masafumi; Kiyono, Tohru; Horie, Kengo; Hirayama, Takashi; Eitsuka, Takahiro; Kuroda, Kengo; Donai, Kenichiro; Hidema, Shizu; Nishimori, Katsuhiko; Fukuda, Tomokazu

2016-01-01

The prairie vole (Microtus ochrogaster) shows social behaviors such as monogamy and parenting of infants with pair bonding. These social behaviors are specific to the prairie vole and have not been observed in other types of voles, such as mountain voles. Although the prairie vole has several unique characteristics, an in vitro cell culture system has not been established for this species. Furthermore, establishment of cultured cells derived from the prairie vole may be beneficial based on the three Rs (i.e., Replacement, Reduction, and Refinement) concept. Therefore, in this study, we attempted to establish an immortalized cell line derived from the prairie vole. Our previous research has shown that transduction with mutant forms of cyclin-dependent kinase 4 (CDK4), cyclin D, and telomerase reverse transcriptase (TERT) could efficiently immortalize cells from multiple species, including humans, cattle, pigs, and monkeys. Here, we introduced these three genes into prairie vole-derived muscle fibroblasts. The expression of mutant CDK4 and cyclin D proteins was confirmed by western blotting, and telomerase activity was detected in immortalized vole muscle-derived fibroblasts (VMF-K4DT cells or VMFs) by stretch PCR. Population doubling analysis showed that the introduction of mutant CDK4, cyclin D, and TERT extended the lifespan of VMFs. To the best of our knowledge, this is the first report describing the establishment of an immortalized cell line derived from the prairie vole through the expression of mutant CDK4, cyclin D, and human TERT.

Low-intensity pulsed ultrasound promotes Schwann cell viability and proliferation via the GSK-3β/β-catenin signaling pathway

PubMed Central

Ren, Cong; Chen, Xiaohui; Du, Ning; Geng, Shuo; Hu, Yingying; Liu, Xin; Wu, Xianxian; Lin, Yuan; Bai, Xue; Yin, Wenzhe; Cheng, Shi; Yang, Lei; Zhang, Yong

2018-01-01

Background: It has been reported that ultrasound enhances peripheral nerve regeneration, but the mechanism remains elusive. Low-intensity pulsed ultrasound (LIPUS) has been reported to enhance proliferation and alter protein production in various types of cells. In this study, we detected the effects of LIPUS on Schwann cells. Material and methods: Schwann cells were separated from new natal Sprague-Dawley rat sciatic nerves and were cultured and purified. The Schwann cells were treated by LIPUS for 10 minutes every day, with an intensity of 27.37 mW/cm2. After treatment for 5 days, MTT, EdU staining, and flow cytometry were performed to examine cell viability and proliferation. Neurotrophic factors, including FGF, NGF, BDNF, and GDNF, were measured by western blot and real-time PCR. GSK-3β, p-GSK-3β, β-catenin and Cyclin D1 protein levels were detected using a western blot analysis. The expression of Cyclin D1 was also detected by immunofluorescence. Results: MTT and EdU staining showed that LIPUS increased the Schwann cells viability and proliferation. Compared to the control group, LIPUS increased the expression of growth factors and neurotrophic factors, including FGF, NGF, BDNF, GDNF, and Cyclin D1. Meanwhile, GSK-3β activity was inhibited in the LIPUS group as demonstrated by the increased level of p-GSK-3β and the ratio of the p-GSK-3β/GSK-3β level. The mRNA and protein expressions of β-catenin were increased in the LIPUS group. However, SB216763, a GSK-3β inhibitor, reversed the effects of LIPUS on Schwann cells. Conclusion: LIPUS promotes Schwann cell viability and proliferation by increasing Cyclin D1 expression via enhancing the GSK-3β/β-catenin signaling pathway.

AP-1 Inhibition by SR 11302 Protects Human Hepatoma HepG2 Cells from Bile Acid-Induced Cytotoxicity by Restoring the NOS-3 Expression

PubMed Central

González-Rubio, Sandra; Linares, Clara I.; Aguilar-Melero, Patricia; Rodríguez-Perálvarez, Manuel; Montero-Álvarez, José L.

2016-01-01

The harmful effects of bile acid accumulation occurring during cholestatic liver diseases have been associated with oxidative stress increase and endothelial nitric oxide synthase (NOS-3) expression decrease in liver cells. We have previously reported that glycochenodeoxycholic acid (GCDCA) down-regulates gene expression by increasing SP1 binding to the NOS-3 promoter in an oxidative stress dependent manner. In the present study, we aimed to investigate the role of transcription factor (TF) AP-1 on the NOS-3 deregulation during GCDCA-induced cholestasis. The cytotoxic response to GCDCA was characterized by 1) the increased expression and activation of TFs cJun and c-Fos; 2) a higher binding capability of these at position -666 of the NOS-3 promoter; 3) a decrease of the transcriptional activity of the promoter and the expression and activity of NOS-3; and 4) the expression increase of cyclin D1. Specific inhibition of AP-1 by the retinoid SR 11302 counteracted the cytotoxic effects induced by GCDCA while promoting NOS-3 expression recovery and cyclin D1 reduction. NOS activity inhibition by L-NAME inhibited the protective effect of SR 11302. Inducible NOS isoform was no detected in this experimental model of cholestasis. Our data provide direct evidence for the involvement of AP-1 in the NOS-3 expression regulation during cholestasis and define a critical role for NOS-3 in regulating the expression of cyclin D1 during the cell damage induced by bile acids. AP-1 appears as a potential therapeutic target in cholestatic liver diseases given its role as a transcriptional repressor of NOS-3. PMID:27490694

Glutamate promotes neural stem cell proliferation by increasing the expression of vascular endothelial growth factor of astrocytes in vitro.

PubMed

Liu, C X; Xu, X; Chen, X L; Yang, P B; Zhang, J S; Liu, Y

2015-09-20

The high levels of glutamate might involve in neurogenesis after brain injuries. However, the mechanisms are not fully understood. In this study, we investigated the effect of glutamate on the proliferation of rat embryonic neural stem/progenitor cells (NSCs) through regulating the vascular endothelial growth factor (VEGF) expression of astrocytes (ASTs) in vitro, and the cyclin D1 expression of NSCs. The results showed that glutamate promoted the expression and secretion of VEGF of rat astrocytes by activating group I mGluRs. Astrocyte conditioned medium-containing Glu [ACM (30%)] promoted the proliferation of embryonic NSCs compared with normal astrocyte conditioned medium+Glu [N-ACM (30%)+Glu (30 μM)] by increasing cell activity, diameter of neurospheres, bromodeoxyuridine (BrdU) incorporation and cell division; while ACM+VEGF neutralizing antibody [ACM (30%)+VEGF NAb (15 μg/ml)] significantly inhibited the proliferation of embryonic NSCs compared with ACM (30%). ACM (30%) increased the expressions of cyclin D1 and decreased cell death compared with N-ACM (30%)+Glu (30 μM). ACM (30%)+VEGF NAb (15 μg/ml) decreased the expressions of cyclin D1 and increased cell death compared with ACM (30%). These results demonstrated that glutamate could also indirectly promote the proliferation of rat embryonic NSCs through inducing the VEGF expression of ASTs in vitro, and VEGF may increase the expression of cyclin D1. These finding suggest that glutamate may be a major molecule for regulating embryonic NSC proliferation and facilitate neural repair in the process of NSC transplants after brain injuries.

Coffee Polyphenols Change the Expression of STAT5B and ATF-2 Modifying Cyclin D1 Levels in Cancer Cells

PubMed Central

Oleaga, Carlota; Ciudad, Carlos J.; Noé, Véronique; Izquierdo-Pulido, Maria

2012-01-01

Background. Epidemiological studies suggest that coffee consumption reduces the risk of cancer, but the molecular mechanisms of its chemopreventive effects remain unknown. Objective. To identify differentially expressed genes upon incubation of HT29 colon cancer cells with instant caffeinated coffee (ICC) or caffeic acid (CA) using whole-genome microarrays. Results. ICC incubation of HT29 cells caused the overexpression of 57 genes and the underexpression of 161, while CA incubation induced the overexpression of 12 genes and the underexpression of 32. Using Venn-Diagrams, we built a list of five overexpressed genes and twelve underexpressed genes in common between the two experimental conditions. This list was used to generate a biological association network in which STAT5B and ATF-2 appeared as highly interconnected nodes. STAT5B overexpression was confirmed at the mRNA and protein levels. For ATF-2, the changes in mRNA levels were confirmed for both ICC and CA, whereas the decrease in protein levels was only observed in CA-treated cells. The levels of cyclin D1, a target gene for both STAT5B and ATF-2, were downregulated by CA in colon cancer cells and by ICC and CA in breast cancer cells. Conclusions. Coffee polyphenols are able to affect cyclin D1 expression in cancer cells through the modulation of STAT5B and ATF-2. PMID:22919439

Modifications in cell cycle kinetics and in expression of G1 phase-regulating proteins in human amniotic cells after exposure to electromagnetic fields and ionizing radiation.

PubMed

Lange, S; Viergutz, T; Simkó, M

2004-10-01

Low-frequency electromagnetic fields are suspected of being involved in carcinogenesis, particularly in processes that could be related to cancer promotion. Because development of cancer is associated with deregulated cell growth and we previously observed a magnetic field-induced decrease in DNA synthesis [Lange et al. (2002) Alterations in the cell cycle and in the protein level of cyclin D1p, 21CIP1, and p16INK4a after exposure to 50 HZ. MF in human cells. Radiat. Environ. Biophys.41, 131], this study aims to document the influence of 50 Hz, 1 mT magnetic fields (MF), with or without initial gamma-ionizing radiation (IR), on the following cell proliferation-relevant parameters in human amniotic fluid cells (AFC): cell cycle distribution, expression of the G1 phase-regulating proteins Cdk4, cyclin D1, p21CIP1 and p16INK4a, and Cdk4 activity. While IR induced a G1 delay and a dose-dependent G2 arrest, no discernible changes in cell cycle kinetics were observed due to MF exposure. However, a significant decrease in the protein expression of cyclin D1 and an increase in p21CIP1- and p16INK4a-expression could be detected after exposure to MF alone. IR-exposure caused an augmentation of p21CIP1- and p16INK4a- levels as well, but did not alter cyclin D1 expression. A slight diminution of Cdk4 activity was noticed after MF exposure only, indicating that Cdk4 appears not to act as a mediator of MF- or IR-induced changes in the cell cycle of AFC cells. Co-exposure to MF/IR affected neither cell cycle distribution nor protein expression or kinase activity additionally or synergistically, and therefore MF seems not to modify the mutagenic potency of IR.

Downregulation of Pygopus 2 inhibits vascular mimicry in glioma U251 cells by suppressing the canonical Wnt signaling pathway

PubMed Central

WANG, HAIDONG; FU, JIANHUA; XU, DIANSHUANG; XU, WEIWEI; WANG, SHIYONG; ZHANG, LIU; XIANG, YONGSHENG

2016-01-01

Gliomas are the most common type of malignant primary brain tumor, and the Wnt signaling pathway is associated with glioma malignancy. Pygopus protein plays an important role in developmental brain patterning, and has been identified to be a component of the Wnt signaling pathway. In the present study, the Pygopus 2 (Pygo2) protein was examined in 80 glioma tissue samples. Short hairpin (sh)RNA-Pygo2 was transfected into glioma U251 cells, and the cell proliferation, colony formation and bromodeoxyuridine (BrdU) incorporation were analyzed. Western blot analysis and reverse transcription-polymerase chain reaction were used to detect the expression of Pygo2. A vascular mimicry assay was performed to examine the vascular mimicry of U251 cells. A luciferase reporter assay was used to detect the β-catenin/Wnt system. The cyclin D1 protein was also detected using western blot analysis. The results demonstrated that inhibition of the expression of Pygo2 significantly triggered the decrease of cell proliferation, colony formation and BrdU incorporation compared with the cells treated with scramble control shRNA (shRNA-Scr). shRNA-Pygo2 transfection was found to inhibit vascular-mimicry and block the Wnt signaling pathway compared to the cells transfected with shRNA-Scr. The transfection of shRNA-Pygo2 also decreased the expression of the Wnt target gene cyclin D1. In conclusion, shRNA-Pygo2 suppressed glioma cell proliferation effectively and inhibited vascular mimicry by inhibiting the expression of cyclin D1 in the canonical Wnt/β-catenin pathway in brain glioma cells. PMID:26870266

Oleanolic acid induces p53-dependent apoptosis via the ERK/JNK/AKT pathway in cancer cell lines in prostatic cancer xenografts in mice.

PubMed

Kim, Gyeong-Ji; Jo, Hyeon-Ju; Lee, Kwon-Jai; Choi, Jeong Woo; An, Jeung Hee

2018-05-29

We evaluated oleanolic acid (OA)-induced anti-cancer activity, apoptotic mechanism, cell cycle status, and MAPK kinase signaling in DU145 (prostate cancer), MCF-7 (breast cancer), U87 (human glioblastoma), normal murine liver cell (BNL CL.2) and human foreskin fibroblast cell lines (Hs 68). The IC50 values for OA-induced cytotoxicity were 112.57 in DU145, 132.29 in MCF-7, and 163.60 in U87 cells, respectively. OA did not exhibit toxicity in BNL CL. 2 and Hs 68 cell lines in our experiments. OA, at 100 µg/mL, increased the number of apoptotic cells to 27.0% in DU145, 27.0% in MCF-7, and 15.7% in U87, when compared to control cells. This enhanced apoptosis was due to increases in p53, cytochrome c, Bax, PARP-1 and caspase-3 expression in DU145, MCF-7 and U87 cell lines. OA-treated DU145 cells were arrested in G2 because of the activation of p-AKT, p-JNK, p21 and p27, and the decrease in p-ERK, cyclin B1 and CDK2 expression; OA-treated MCF-7 cells were arrested in G1 owing to the activation of p-JNK, p-ERK, p21, and p27, and the decrease in p-AKT, cyclin D1, CDK4, cyclin E, and CDK2; and OA-treated U87 cells also exhibited G1 phase arrest caused by the increase in p-ERK, p-JNK, p-AKT, p21, and p27, and the decrease in cyclin D1, CDK4, cyclin E and CDK2. Thus, OA arrested the cell cycle at different phases and induced apoptosis in cancer cells. These results suggested that OA possibly altered the expression of the cell cycle regulatory proteins differently in varying types of cancer.

HIRA, the Human Homologue of Yeast Hir1p and Hir2p, Is a Novel Cyclin-cdk2 Substrate Whose Expression Blocks S-Phase Progression

PubMed Central

Hall, Caitlin; Nelson, David M.; Ye, Xiaofen; Baker, Kayla; DeCaprio, James A.; Seeholzer, Steven; Lipinski, Marc; Adams, Peter D.

2001-01-01

Substrates of cyclin-cdk2 kinases contain two distinct primary sequence motifs: a cyclin-binding RXL motif and one or more phosphoacceptor sites (consensus S/TPXK/R or S/TP). To identify novel cyclin-cdk2 substrates, we searched the database for proteins containing both of these motifs. One such protein is human HIRA, the homologue of two cell cycle-regulated repressors of histone gene expression in Saccharomyces cerevisiae, Hir1p and Hir2p. Here we demonstrate that human HIRA is an in vivo substrate of a cyclin-cdk2 kinase. First, HIRA bound to and was phosphorylated by cyclin A- and E-cdk2 in vitro in an RXL-dependent manner. Second, HIRA was phosphorylated in vivo on two consensus cyclin-cdk2 phosphoacceptor sites and at least one of these, threonine 555, was phosphorylated by cyclin A-cdk2 in vitro. Third, phosphorylation of HIRA in vivo was blocked by cyclin-cdk2 inhibitor p21cip1. Fourth, HIRA became phosphorylated on threonine 555 in S phase when cyclin-cdk2 kinases are active. Fifth, HIRA was localized preferentially to the nucleus, where active cyclin A- and E-cdk2 are located. Finally, ectopic expression of HIRA in cells caused arrest in S phase and this is consistent with the notion that it is a cyclin-cdk2 substrate that has a role in control of the cell cycle. PMID:11238922

E2F1-mediated upregulation of p19INK4d determines its periodic expression during cell cycle and regulates cellular proliferation.

PubMed

Carcagno, Abel L; Marazita, Mariela C; Ogara, María F; Ceruti, Julieta M; Sonzogni, Silvina V; Scassa, María E; Giono, Luciana E; Cánepa, Eduardo T

2011-01-01

A central aspect of development and disease is the control of cell proliferation through regulation of the mitotic cycle. Cell cycle progression and directionality requires an appropriate balance of positive and negative regulators whose expression must fluctuate in a coordinated manner. p19INK4d, a member of the INK4 family of CDK inhibitors, has a unique feature that distinguishes it from the remaining INK4 and makes it a likely candidate for contributing to the directionality of the cell cycle. p19INK4d mRNA and protein levels accumulate periodically during the cell cycle under normal conditions, a feature reminiscent of cyclins. In this paper, we demonstrate that p19INK4d is transcriptionally regulated by E2F1 through two response elements present in the p19INK4d promoter. Ablation of this regulation reduced p19 levels and restricted its expression during the cell cycle, reflecting the contribution of a transcriptional effect of E2F1 on p19 periodicity. The induction of p19INK4d is delayed during the cell cycle compared to that of cyclin E, temporally separating the induction of these proliferative and antiproliferative target genes. Specific inhibition of the E2F1-p19INK4d pathway using triplex-forming oligonucleotides that block E2F1 binding on p19 promoter, stimulated cell proliferation and increased the fraction of cells in S phase. The results described here support a model of normal cell cycle progression in which, following phosphorylation of pRb, free E2F induces cyclin E, among other target genes. Once cyclinE/CDK2 takes over as the cell cycle driving kinase activity, the induction of p19 mediated by E2F1 leads to inhibition of the CDK4,6-containing complexes, bringing the G1 phase to an end. This regulatory mechanism constitutes a new negative feedback loop that terminates the G1 phase proliferative signal, contributing to the proper coordination of the cell cycle and provides an additional mechanism to limit E2F activity.

E2F1-Mediated Upregulation of p19INK4d Determines Its Periodic Expression during Cell Cycle and Regulates Cellular Proliferation

PubMed Central

Carcagno, Abel L.; Marazita, Mariela C.; Ogara, María F.; Ceruti, Julieta M.; Sonzogni, Silvina V.; Scassa, María E.; Giono, Luciana E.; Cánepa, Eduardo T.

2011-01-01

Background A central aspect of development and disease is the control of cell proliferation through regulation of the mitotic cycle. Cell cycle progression and directionality requires an appropriate balance of positive and negative regulators whose expression must fluctuate in a coordinated manner. p19INK4d, a member of the INK4 family of CDK inhibitors, has a unique feature that distinguishes it from the remaining INK4 and makes it a likely candidate for contributing to the directionality of the cell cycle. p19INK4d mRNA and protein levels accumulate periodically during the cell cycle under normal conditions, a feature reminiscent of cyclins. Methodology/Principal Findings In this paper, we demonstrate that p19INK4d is transcriptionally regulated by E2F1 through two response elements present in the p19INK4d promoter. Ablation of this regulation reduced p19 levels and restricted its expression during the cell cycle, reflecting the contribution of a transcriptional effect of E2F1 on p19 periodicity. The induction of p19INK4d is delayed during the cell cycle compared to that of cyclin E, temporally separating the induction of these proliferative and antiproliferative target genes. Specific inhibition of the E2F1-p19INK4d pathway using triplex-forming oligonucleotides that block E2F1 binding on p19 promoter, stimulated cell proliferation and increased the fraction of cells in S phase. Conclusions/Significance The results described here support a model of normal cell cycle progression in which, following phosphorylation of pRb, free E2F induces cyclin E, among other target genes. Once cyclinE/CDK2 takes over as the cell cycle driving kinase activity, the induction of p19 mediated by E2F1 leads to inhibition of the CDK4,6-containing complexes, bringing the G1 phase to an end. This regulatory mechanism constitutes a new negative feedback loop that terminates the G1 phase proliferative signal, contributing to the proper coordination of the cell cycle and provides an additional mechanism to limit E2F activity. PMID:21765927

Chemopreventive potential of in vitro fermented nuts in LT97 colon adenoma and primary epithelial colon cells.

PubMed

Schlörmann, Wiebke; Lamberty, Julia; Lorkowski, Stefan; Ludwig, Diana; Mothes, Henning; Saupe, Christian; Glei, Michael

2017-05-01

Due to their beneficial nutritional profile the consumption of nuts contributes to a healthy diet and might reduce colon cancer risk. To get closer insights into potential mechanisms, the chemopreventive potential of different in vitro fermented nut varieties regarding the modulation of genes involved in detoxification (CAT, SOD2, GSTP1, GPx1) and cell cycle (p21, cyclin D2) as well as proliferation and apoptosis was examined in LT97 colon adenoma and primary epithelial colon cells. Fermentation supernatants (FS) of nuts significantly induced mRNA expression of CAT (up to 4.0-fold), SOD2 (up to 2.5-fold), and GSTP1 (up to 2.3-fold), while GPx1 expression was significantly reduced by all nut FS (0.8 fold on average). Levels of p21 mRNA were significantly enhanced (up to 2.6-fold), whereas all nut FS significantly decreased cyclin D2 expression (0.4-fold on average). In primary epithelial cells, expression of CAT (up to 3.5-fold), GSTP1 (up to 3.0-fold), and GPx1 (up to 3.9-fold) was increased, whereas p21 and cyclin D2 levels were not influenced. Nut FS significantly inhibited growth of LT97 cells and increased levels of early apoptotic cells (8.4% on average) and caspase 3 activity (4.6-fold on average), whereas caspase 3 activity was not modulated in primary colon cells. The differential modulation of genes involved in detoxification and cell cycle together with an inhibition of proliferation and induction of apoptosis in adenoma cells might contribute to chemopreventive effects of nuts regarding colon cancer. © 2017 Wiley Periodicals, Inc.

Expression of cyclooxygenase-2 in normal urothelium, and superficial and advanced transitional cell carcinoma of bladder.

PubMed

Margulis, Vitaly; Shariat, Shahrokh F; Ashfaq, Raheela; Thompson, Melissa; Sagalowsky, Arthur I; Hsieh, Jer-Tsong; Lotan, Yair

2007-03-01

We compared the differential expression of cyclooxygenase-2 in normal bladder tissue, primary bladder transitional cell carcinoma and transitional cell carcinoma metastases to lymph nodes, and determined whether cyclooxygenase-2 expression is associated with molecular alterations commonly found in bladder transitional cell carcinoma and clinical outcomes after radical cystectomy. Immunohistochemical staining for cyclooxygenase-2, survivin (Novus Biologicals, Littleton, Colorado), p21, p27, pRB, p53, MIB-1, Bax, Bcl-2, cyclin D(1) (Dakotrade mark), cyclin E (Oncogene, Cambridge, Massachusetts) and caspase-3 (Cell Signaling, Beverley, Massachusetts) was performed on archival bladder specimens from 9 subjects who underwent cystectomy for benign causes, 21 patients who underwent transurethral resection and 157 consecutive patients after radical cystectomy, and on 41 positive lymph nodes. Cyclooxygenase-2 was expressed in none of the 9 normal bladder specimens (0%), 52% of transurethral resection specimens, 62% of cystectomy specimens and 80% of lymph nodes involved with transitional cell carcinoma. Cyclooxygenase-2 expression was associated with higher pathological stage, lymphovascular invasion and metastases to lymph nodes (p=0.001, 0.045 and 0.002, respectively). Cyclooxygenase-2 expression was associated with altered expression of p53 (p=0.039), pRB (p=0.025), cyclin D1 (p=0.034) and caspase-3 (p=0.014). On univariate analysis cyclooxygenase-2 expression was associated with an increased risk of disease recurrence and bladder cancer specific mortality (p=0.0189 and 0.0472, respectively). However, on multivariate analysis only pathological stage and metastases to lymph nodes were associated with disease recurrence (p<0.001 and <0.001) and survival (p<0.001 and 0.015, respectively). Cyclooxygenase-2 is not expressed in normal bladder urothelium. Cyclooxygenase-2 over expression is associated with pathological and molecular features of biologically aggressive disease, suggesting a role for cyclooxygenase-2 in bladder cancer development and invasion.

Crosstalk between HIF-1 and ROCK pathways in neuronal differentiation of mesenchymal stem cells, neurospheres and in PC12 neurite outgrowth.

PubMed

Pacary, Emilie; Tixier, Emmanuelle; Coulet, Florence; Roussel, Simon; Petit, Edwige; Bernaudin, Myriam

2007-07-01

This study demonstrates that the Rho-kinase (ROCK) inhibitor, Y-27632, potentiates not only the effect of cobalt chloride (CoCl(2)) but also that of deferoxamine, another HIF-1 inducer, on mesenchymal stem cell (MSC) neuronal differentiation. HIF-1 is essential for CoCl(2)+/-Y-27632-induced MSC neuronal differentiation, since agents inhibiting HIF-1 abolish the changes of morphology and cell cycle arrest-related gene or protein expressions (p21, cyclin D1) and the increase of neuronal marker expressions (Tuj1, NSE). Y-27632 potentiates the CoCl(2)-induced decrease of cyclin D1 and nestin expressions, the increase of HIF-1 activation and EPO expression, and decreases pVHL expression. Interestingly, CoCl(2) decreases RhoA expression, an effect potentiated by Y-27632, revealing crosstalk between HIF-1 and RhoA/ROCK pathways. Moreover, we demonstrate a synergistic effect of CoCl(2) and Y-27632 on neurosphere differentiation into neurons and PC12 neurite outgrowth underlining that a co-treatment targeting both HIF-1 and ROCK pathways might be relevant to differentiate stem cells into neurons.

Perinatal exposure to BDE-99 causes decreased protein levels of cyclin D1 via GSK3β activation and increased ROS production in rat pup livers.

PubMed

Blanco, Jordi; Mulero, Miquel; Domingo, Jose L; Sanchez, Domènec J

2014-02-01

We here examined the potential liver toxicity in rat pups from dams exposed during the gestational and lactation periods to 2,2',4,4',5-pentabromodiphenyl ether (BDE-99). Dams were exposed to 0, 1, and 2mg/kg/day of BDE-99 from gestation day 6 to postnatal day 21. When the pups were weaning, the liver from 1 pup of each litter was excised to evaluate oxidative stress markers and the messenger RNA (mRNA) expression of multiple cytochrome P450 (CYP) isoforms. To determine whether thyroid hormone (TH) was disrupted, the protein and mRNA expressions of several TH receptor (TR) isoforms, as well as the protein levels of cyclin D1 and the phosphorylated protein kinases Akt and glycogen synthase kinase 3 beta (GSK3β), were evaluated. Perinatal exposure to BDE-99 produced decreased levels of cyclin D1 in rat pup livers. A decrease in the active form of Akt and an increase in the active form of GSK3β were observed. The decreased Akt pathway may be due to a potential disruption of the nongenomic actions of TH by BDE-99 and its metabolites. This possible TH disruption was noted as a decrease in TR isoforms expression. By contrast, we observed an upregulation of CYP2B1 gene expression, which is correlated with an increase in reactive oxygen species production. This outcome indicates activation of the nuclear constitutive androstane receptor, which could induce the expression of other enzymes capable of metabolizing TH. The present findings support the hypothesis that perinatal exposure to PBDEs, at levels found in humans, may have serious implications for metabolic processes in rat pup livers.

Effects of a combined treatment with GPR30 agonist G-1 and herceptin on growth and gene expression of human breast cancer cell lines.

PubMed

Lubig, Julia; Lattrich, Claus; Springwald, Anette; Häring, Julia; Schüler, Susanne; Ortmann, Olaf; Treeck, Oliver

2012-06-01

Expression of G-protein-coupled receptor 30 (GPR30) is present in HER2-overexpressing breast cancer. In this study, we examined to what extent GPR30-agonist G-1 would affect the antitumoral action of trastuzumab (Herceptin). Combined treatment with both drugs exerted an additive growth-inhibitory effect on breast cancer cells which was accompanied by a significant decline of cyclin A2 expression both on the protein and the mRNA level. Combined treatment also resulted in expression changes of c-fos, cyclin D1, or p21/WAF-1. The results of our study encourage further attempts to test the relevance of these in vitro data in the clinical setting.

Increase in Ara-C cytotoxicity in the presence of valproate, a histone deacetylase inhibitor, is associated with the concurrent expression of cyclin D1 and p27(Kip 1) in acute myeloblastic leukemia cells.

PubMed

Siitonen, Timo; Koistinen, Pirjo; Savolainen, Eeva-Riitta

2005-11-01

The effects of valproate and butyrate were investigated in an acute myeloblastic cell line (OCI/AML-2) on cytotoxicity, cell cycle profile and expression of cell cycle regulating proteins in the presence of cytarabine (Ara-C) and etoposide. As a single agent valproate and butyrate inhibited AML cell growth but did not significantly induce cell death. A dramatic increase in cytotoxicity was observed when combining valproate or butyrate with Ara-C, whereas, co-addition of them with etoposide had much smaller effect on cell death. Valproate induced a clear G1 phase arrest and up-regulated cyclin D1 expression in the presence of Ara-C and etoposide. In addition, valporate was able to block the Ara-C-induced down-regulation of p27(Kip1) expression but not that induced by etoposide.

Up-regulation of Pim-3 in Chronic Obstructive Pulmonary Disease (COPD) patients and its potential therapeutic role in COPD rat modeling.

PubMed

Yang, Cheng; Li, Li; Guo, Junhua; Zhang, Weiqiang; Zhu, Wenbiao; Rao, Xinhui; Huang, Wenjie

2017-04-01

Pim-3 belongs to the PIM kinase family and plays an important role in promoting inflammation, which is essential in the pathogenesis of Chronic Obstructive Pulmonary Disease (COPD). Immunohistochemistry (IHC), western blot, and RT-PCR analyses were performed to assess the expression of Pim-3 in both COPD and healthy lung tissue samples. SMA (Smooth Muscle Actin) and Cyclin D1 expression were detected by IHC. We also constructed animal models for the control, COPD, and Pim-3 inhibition groups, in order to analyze the effects of Pim-3 inhibition on COPD, and the role of Pim-3 in the p38 pathway. Compared with normal lung tissue, Pim-3 mRNA and protein were up-regulated in COPD tissue. Expression of Cyclin D1 and SMA were also up-regulated in the COPD group. In the animal model experiment, we found that suppression of Pim-3 decreased Pim-3, Cyclin D1, and SMA expression, as well as ameliorated lung damage in COPD patients. The inhibition of Pim-3 also resulted in the suppression of the p38 pathway. Our study suggests that up-regulation of Pim-3 successfully accelerated COPD development, and aggravated lung damage. The molecular mechanism of Pim-3 in COPD might be related to the p38 pathway, and is correlated with Cyclin D1 and SMA expression. Copyright © 2017 Elsevier GmbH. All rights reserved.

Role of NADPH oxidases in inducing a selective increase of oxidant stress and cyclin D1 and checkpoint 1 over-expression during progression to human gastric adenocarcinoma.

PubMed

Montalvo-Javé, Eduardo E; Olguín-Martínez, Marisela; Hernández-Espinosa, Diego R; Sánchez-Sevilla, Lourdes; Mendieta-Condado, Edgar; Contreras-Zentella, Martha L; Oñate-Ocaña, Luis F; Escalante-Tatersfield, Tomás; Echegaray-Donde, Agustín; Ruiz-Molina, Juan M; Herrera, Miguel F; Morán, Julio; Hernández-Muñoz, Rolando

2016-04-01

Gastric cancer is one of the main causes of global mortality. Here, reactive oxygen species (ROS) could largely contribute to gastric carcinogenesis. Hence, the present work was aimed to assess the role of ROS, oxidant status, NADPH oxidases (NOXs) expression, during human gastric adenocarcinoma. We obtained subcellular fraction from samples of gastric mucosa taken from control subjects (n = 20), and from 40 patients with gastric adenocarcinoma, as well as samples of distant areas (tumour-free gastric mucosa). Parameters indicative of lipid peroxidation and cell proliferation were selectively increased in both tumour-free and in cancerous gastric mucosa, despite of glutathione (GSH) content, glutathione reductase (GR) and superoxide dismutase (SOD) activities were increased in the adenocarcinoma. These high levels of antioxidant defences inversely correlated with down-regulated expression for NOX2 and 4; however, over-expression of NOX1 occurred with increased caspase-3 activity and overexpressed checkpoint 1 (MDC1) and cyclin D1 proteins. In the tumour-free mucosa an oxidant stress took place, without changing total GSH but with decreased activities for GR and mitochondrial SOD; moreover, over-expression of checkpoint 1 (MDC1) correlated with lower NOX2 and 4 expression in this mucosa. Chronically injured gastric mucosa increases lipoperoxidative events and cell proliferation. In the adenocarcinoma, cell proliferation was further enhanced, oxidant stress decreased which seemed to be linked to NOX1, MDC1 and cyclin D1 over-expression, but with a lower NOXs activity leading a 'low tone' of ROS formation. Therefore, our results could be useful for early detection and treatment of gastric adenocarcinoma. Copyright © 2016 Elsevier Ltd. All rights reserved.

CDK4 inhibition and doxorubicin mediate breast cancer cell apoptosis through Smad3 and survivin

PubMed Central

Tarasewicz, Elizabeth; Hamdan, Randala; Straehla, Joelle; Hardy, Ashley; Nunez, Omar; Zelivianski, Stanislav; Dokic, Danijela; Jeruss, Jacqueline S

2014-01-01

Cyclin D1/CDK4 activity is upregulated in up to 50% of breast cancers and CDK4-mediated phosphorylation negatively regulates the TGFβ superfamily member Smad3. We sought to determine if CDK4 inhibition and doxorubicin chemotherapy could impact Smad3-mediated cell/colony growth and apoptosis in breast cancer cells. Parental and cyclin D1-overexpressing MCF7 cells were treated with CDK4 inhibitor, doxorubicin, or combination therapy and cell proliferation, apoptosis, colony formation, and expression of apoptotic proteins were evaluated using an MTS assay, TUNEL staining, 3D Matrigel assay, and apoptosis array/immunoblotting. Study cells were also transduced with WT Smad3 or a Smad3 construct resistant to CDK4 phosphorylation (5M) and colony formation and expression of apoptotic proteins were assessed. Treatment with CDK4 inhibitor/doxorubicin combination therapy, or transduction with 5M Smad3, resulted in a similar decrease in colony formation. Treating cyclin D overexpressing breast cancer cells with combination therapy also resulted in the greatest increase in apoptosis, resulted in decreased expression of anti-apoptotic proteins survivin and XIAP, and impacted subcellular localization of pro-apoptotic Smac/DIABLO. Additionally, transduction of 5M Smad3 and doxorubicin treatment resulted in the greatest change in apoptotic protein expression. Collectively, this work showed the impact of CDK4 inhibitor-mediated, Smad3-regulated tumor suppression, which was augmented in doxorubicin-treated cyclin D-overexpressing study cells. PMID:25006666

The prognostic implication of the expression of EGFR, p53, cyclin D1, Bcl-2 and p16 in primary locally advanced oral squamous cell carcinoma cases: a tissue microarray study.

PubMed

Solomon, Monica Charlotte; Vidyasagar, M S; Fernandes, Donald; Guddattu, Vasudev; Mathew, Mary; Shergill, Ankur Kaur; Carnelio, Sunitha; Chandrashekar, Chetana

2016-12-01

Oral squamous cell carcinomas comprise a heterogeneous tumor cell population with varied molecular characteristics, which makes prognostication of these tumors a complex and challenging issue. Thus, molecular profiling of these tumors is advantageous for an accurate prognostication and treatment planning. This is a retrospective study on a cohort of primary locally advanced oral squamous cell carcinomas (n = 178) of an Indian rural population. The expression of EGFR, p53, cyclin D1, Bcl-2 and p16 in a cohort of primary locally advanced oral squamous cell carcinomas was evaluated. A potential biomarker that can predict the tumor response to treatment was identified. Formalin-fixed paraffin-embedded tumor blocks of (n = 178) of histopathologically diagnosed cases of locally advanced oral squamous cell carcinomas were selected. Tissue microarray blocks were constructed with 2 cores of 2 mm diameter from each tumor block. Four-micron-thick sections were cut from these tissue microarray blocks. These tissue microarray sections were immunohistochemically stained for EGFR, p53, Bcl-2, cyclin D1 and p16. In this cohort, EGFR was the most frequently expressed 150/178 (84%) biomarker of the cases. Kaplan-Meier analysis showed a significant association (p = 0.038) between expression of p53 and a poor prognosis. A Poisson regression analysis showed that tumors that expressed p53 had a two times greater chance of recurrence (unadjusted IRR-95% CI 2.08 (1.03, 4.5), adjusted IRR-2.29 (1.08, 4.8) compared with the tumors that did not express this biomarker. Molecular profiling of oral squamous cell carcinomas will enable us to categorize our patients into more realistic risk groups. With biologically guided tumor characterization, personalized treatment protocols can be designed for individual patients, which will improve the quality of life of these patients.

1, 25(OH){sub 2}D{sub 3}-induced interaction of vitamin D receptor with p50 subunit of NF-κB suppresses the interaction between KLF5 and p50, contributing to inhibition of LPS-induced macrophage proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Dong; School of Public Health, North China University of Science and Technology, Tangshan, Hebei, 063000; Zhang, Ruo-nan

KLF5 and nuclear factor κB (NF-κB) regulate cell proliferation and inflammation. Vitamin D signaling through vitamin D receptor (VDR) exerts anti-proliferative and anti-inflammatory actions. However, an actual relationship between KLF5, NF-κB and VDR in the inflammation and proliferation of macrophages is still unclear. Here, we showed that LPS and proinflammatory cytokines stimulate KLF5 gene expression in macrophages, and that 1, 25(OH){sub 2}D{sub 3} suppresses LPS-induced KLF5 expression and cell proliferation via upregulation of VDR expression. Mechanistic studies suggested that KLF5 interacts with p50 subunit of NF-κB to cooperatively induce the expressions of positive cell cycle regulators cyclin B1 and Cdk1/Cdc2more » in LPS-treated macrophages. Further studies revealed that 1, 25(OH){sub 2}D{sub 3}-induced interaction of VDR with p50 decreases LPS-induced interaction of KLF5 with p50. Collectively, we identify a novel regulatory pathway in which 1, 25(OH){sub 2}D{sub 3} induces VDR expression and promotes VDR interaction with p50 subunit of NF-κB, which in turn attenuates the association of KLF5 with p50 subunit of NF-κB and thus exerts anti-inflammatory and anti-proliferative effects on macrophages. - Highlights: • 1, 25(OH){sub 2}D{sub 3} suppresses LPS-induced KLF5 expression via upregulation of VDR expression. • KLF5 interacts with NF-κB-p50 to cooperatively induce the expressions of positive cell cycle regulators cyclin B1 and Cdk1/Cdc2 in LPS-treated macrophages. • 1,25(OH){sub 2}D{sub 3} induces interaction of VDR with p50.« less

Long noncoding RNA SNHG7 accelerates prostate cancer proliferation and cycle progression through cyclin D1 by sponging miR-503.

PubMed

Qi, Honggang; Wen, Bifeng; Wu, Qihang; Cheng, Wei; Lou, Jiangyong; Wei, Junjun; Huang, Jianjun; Yao, Xuping; Weng, Guobin

2018-06-01

Increasing evidence has indicated the important roles of long non-coding RNAs (lncRNAs) in tumorigenesis and cellular progression, including prostate cancer. In this study, we aim to investigate the expression level of SNHG7 and its biological functions on prostate cancer cells. Results indicated that SNHG7 expression was significantly up-regulated in prostate cancer tissue and cell lines. Besides, the overexpression of SNHG7 was closely correlated with the poor prognosis. In vitro and in vivo, experiments demonstrated that SNHG7 knockdown markedly inhibited prostate cancer proliferation and cycle-related protein (CDK4, CDK6, Cyclin D1), induced cell cycle arrest at G0/G1 phase and suppressed tumor growth. Moreover, miR-503 was predicted by bioinformatics tools and validated using luciferase reporter assay to both directly inhibited SNHG7 and Cyclin D1 expression by targeting their RNA 3'-UTR. In conclusion, results present that SNHG7 regulates the cycle progression and acts as an oncogenic gene in the prostate cancer tumorigenesis via miR-503/Cyclin D1 pathway, revealing the vital role of lncRNA/miRNA/mRNA axis in prostate cancer carcinogenesis. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

FAK Regulates Intestinal Epithelial Cell Survival and Proliferation during Mucosal Wound Healing

PubMed Central

Tilghman, Robert W.; Casanova, James E.; Bouton, Amy H.

2011-01-01

Background Following damage to the intestinal epithelium, restoration of epithelial barrier integrity is triggered by a robust proliferative response. In other tissues, focal adhesion kinase (FAK) regulates many of the cellular processes that are critical for epithelial homeostasis and restitution, including cell migration, proliferation and survival. However, few studies to date have determined how FAK contributes to mucosal wound healing in vivo. Methodology and Principal Findings To examine the role of FAK in intestinal epithelial homeostasis and during injury, we generated intestinal epithelium (IE)-specific conditional FAK knockout mice. Colitis was induced with dextran-sulfate-sodium (DSS) and intestinal tissues were analyzed by immunohistochemistry and immunoblotting. While intestinal development occurred normally in mice lacking FAK, FAK-deficient animals were profoundly susceptible to colitis. The loss of epithelial FAK resulted in elevated p53 expression and an increased sensitivity to apoptosis, coincident with a failure to upregulate epithelial cell proliferation. FAK has been reported to function as a mechanosensor, inducing cyclin D1 expression and promoting cell cycle progression under conditions in which tissue/matrix stiffness is increased. Collagen deposition, a hallmark of inflammatory injury resulting in increased tissue rigidity, was observed in control and FAK knockout mice during colitis. Despite this fibrotic response, the colonic epithelium in FAK-deficient mice exhibited significantly reduced cyclin D1 expression, suggesting that proliferation is uncoupled from fibrosis in the absence of FAK. In support of this hypothesis, proliferation of Caco-2 cells increased proportionally with matrix stiffness in vitro only under conditions of normal FAK expression; FAK depleted cells exhibited reduced proliferation concomitant with attenuated cyclin D1 expression. Conclusions In the colon, FAK functions as a regulator of epithelial cell survival and proliferation under conditions of mucosal injury and a mechanosensor of tissue compliance, inducing repair-driven proliferation in the colonic epithelium through upregulation of cyclin D1. PMID:21887232

Cytotoxic activity of the twigs of Cinnamomum cassia through the suppression of cell proliferation and the induction of apoptosis in human colorectal cancer cells.

PubMed

Park, Gwang Hun; Song, Hun Min; Park, Su Bin; Son, Ho-Jun; Um, Yurry; Kim, Hyun-Seok; Jeong, Jin Boo

2018-01-25

Because twigs of Cinnamomum cassia (TC) have been reported to exert anti-cancer activity, the mechanistic study for TC's anti-cancer activity is required. Thus, we elucidated the potential molecular mechanism of TC's anti-proliferative effect and the induction of apoptosis in human colorectal cancer cells. How water extracts form TC (TC-HW) was used in this study. Anti-cell proliferative effect of TC-HW was evaluated by MTT assay. The change of protein or mRNA level by TC-HW was evaluated by Western blot and RT-RCR, respectively. The promoter construct for ATF3, NF-κB, TOP-FLASH or FOP-FLASH was used for the investigation of the transcriptional activity for ATF3, NF-κB or Wnt. siRNA for ATF3 or p65 was used for the knockdown of ATF3 and p65. TC-HW reduced the cell viability in human colorectal cancer cells. TC-HW decreased cyclin D1 protein level through cyclin D1 degradation via GSK3β-dependent threonine-286 (T286) phosphorylation of cyclin D1, indicating that cyclin D1 degradation may contribute to TC-HW-mediated decrease of cyclin D1 protein level. TC-HW downregulated the expression of cyclin D1 mRNA level and inhibited Wnt activation through the downregulation of β-catenin and TCF4 expression, indicating that inhibition of cyclin D1 transcription may also result in TC-HW-mediated decrease of cyclin D1 protein level. In addition, TC-HW was observed to induce apoptosis through ROS-dependent DNA damage. TC-HW-induced ROS increased NF-κB and ATF3 activation, and inhibition of NF-κB and ATF3 activation attenuated TC-HW-mediated apoptosis. Our results suggest that TC-HW may suppress cell proliferation through the downregulation of cyclin D1 via proteasomal degradation and transcriptional inhibition, and may induce apoptosis through ROS-dependent NF-κB and ATF3 activation. These effects of TC-HW may contribute to the reduction of cell viability in human colorectal cancer cells. From these findings, TC-HW has potential to be a candidate for the development of chemoprevention or therapeutic agents for human colorectal cancer.

Magnolol attenuates neointima formation by inducing cell cycle arrest via inhibition of ERK1/2 and NF-kappaB activation in vascular smooth muscle cells.

PubMed

Karki, Rajendra; Ho, Oak-Min; Kim, Dong-Wook

2013-03-01

Endovascular injury induces switching of contractile phenotype of vascular smooth muscle cells (VSMCs) to synthetic phenotype, thereby causing proliferation of VSMCs leading to intimal thickening. The purpose of this study was to assess the effect of magnolol on the proliferation of VSMCs in vitro and neointima formation in vivo, as well as the related cell signaling mechanisms. Tumor necrosis factor alpha (TNF-alpha) induced proliferation ofVSMCs was assessed using colorimetric assay. Cell cycle progression and mRNA expression of cell cycle associated molecules were determined by flow cytometry and reverse transcription polymerase chain reaction (RT-PCR) respectively. The signaling molecules such as ERK1/2,JNK, P38 and NF-kappaB were determined by Western blot analysis. In addition, rat carotid artery balloon injury model was performed to assess the effect of magnolol on neointima formation in vivo. Oral administration of magnolol significantly inhibited intimal area and intimal/medial ratio (I/M). Our in vitro assays revealed magnolol dose dependently induced cell cycle arrest at G0/G1. Also, magnolol inhibited mRNA and protein expression of cyclin D1, cyclin E, CDK4 and CDK2 in vitro and in vivo. The cell cycle arrest was associated with inhibition of ERK1/2 phosphorylation and NF-kappaB translocation. Magnolol suppressed proliferation of VSMCs in vitro and attenuated neointima formation in vivo by inducing cell cycle arrest at G0/G1 through modulation of cyclin D1, cyclin E, CDK4 and CDK2 expression. Thus, the results suggest that magnolol could be a potential therapeutic candidate for the prevention of restenosis and atherosclerosis.

Delayed Administration of a Single Dose of Lithium Promotes Recovery from AKI

PubMed Central

Bao, Hui; Ge, Yan; Wang, Zhen; Zhuang, Shougang; Dworkin, Lance; Peng, Ai

2014-01-01

Evidence suggests that glycogen synthase kinase 3β (GSK3β) contributes to AKI; however, its role in post-AKI kidney repair remains uncertain. Here, delayed treatment with a single dose of lithium, a selective inhibitor of GSK3β and a US Food and Drug Administration–approved mood stabilizer, accelerated recovery of renal function, promoted repopulation of renal tubular epithelia, and improved kidney repair in murine models of cisplatin- and ischemia/reperfusion-induced AKI. These effects associated with reduced GSK3β activity and elevated expression of proproliferative molecules, including cyclin D1, c-Myc, and hypoxia-inducible factor 1α (HIF-1α), in renal tubular epithelia. In cultured renal tubular cells, cisplatin exposure led to transient repression of GSK3β activity followed by a prolonged upregulation of activity. Rescue treatment with lithium inhibited GSK3β activity, enhanced nuclear expression of cyclin D1, c-Myc, and HIF-1α, and boosted cellular proliferation. Similarly, ectopic expression of a kinase-dead mutant of GSK3β enhanced the expression of cyclin D1, c-Myc, and HIF-1α and amplified cellular proliferation after cisplatin injury, whereas forced expression of a constitutively active mutant of GSK3β abrogated the effects of lithium. Mechanistically, GSK3β colocalized and physically interacted with cyclin D1, c-Myc, and HIF-1α in tubular cells. In silico analysis revealed that cyclin D1, c-Myc, and HIF-1α harbor putative GSK3β consensus phosphorylation motifs, implying GSK3β-directed phosphorylation and subsequent degradation of these molecules. Notably, cotreatment with lithium enhanced the proapoptotic effects of cisplatin in cultured colon cancer cells. Collectively, our findings suggest that pharmacologic targeting of GSK3β by lithium may be a novel therapeutic strategy to improve renal salvage after AKI. PMID:24408869

Function of cell-cycle regulators in predicting silent pituitary adenoma progression following surgical resection

PubMed Central

Park, Sung Hyun; Jang, Ji Hwan; Lee, Young Min; Kim, Joon Soo; Kim, Kyu Hong; Kim, Young Zoon

2017-01-01

The present study investigated the use of cell-cycle regulators for predicting the progression of silent pituitary adenoma (SPA) following surgical resection, via immunohistochemical analysis of tumor samples obtained by surgical resection. The medical records of patients diagnosed with SPA between January 2000 and December 2013 in the Samsung Changwon Hospital, Sungkyunkwan University School of Medicine (Changwon, South Korea) were reviewed. Immunohistochemical staining was performed on sections of the archived, paraffin-embedded tissues obtained by surgery, with all tissues stained for cell-cycle regulatory proteins p16, p15, p21, cyclin-dependent kinase (CDK)4, CDK6, retinoblastoma protein (pRb) and cyclin D1, as well as E3 ubiquitin-protein ligase mib1 (MIB-1) antigen and p53. The primary end-point was to investigate the expression of cell-cycle regulatory proteins in SPA. The secondary end-point was to estimate the progression-free survival of patients with SPA following surgical resection and to identify its association with the expression of cell-cycle regulatory proteins. Of the 127 SPA samples, 44 (34.6%) were from patients with progression during a mean follow-up period of 62.4 months (range, 24.2–118.9 months). Immunohistochemical overexpression was identified in 61 samples (48.0%) for p16, 38 samples (29.9%) for p15, 19 samples (15.0%) for p21, 49 samples (38.6%) for CDK4, 17 samples (13.4%) for CDK6, 57 samples (44.9%) for pRb and in 65 samples (51.2%) for cyclin D1. Multivariate analysis revealed that null cell adenoma [95% confidence interval (CI), 0.276–0.808], somatotroph SPAs (95% CI, 1.296–3.121), corticotroph SPAs (95% CI, 1.811–4.078), pluripotent SPAs (95% CI, 2.264–5.194), decreased expression of p16 (95% CI, 2.724–5.588), overexpression of pRb (95% CI, 2.557–5.333), cyclin D1 (95% CI, 1.894–4.122) and MIB-1 (95% CI, 1.561–4.133), increased mitotic index (95% CI, 1.228–4.079), increased p53 expression (95% CI, 1.307–4.065) and invasion into the cavernous sinus (95% CI, 3.842–7.502) predicted SPA progression following resection. The results of the present study suggested that specific cell-cycle regulators, including p16, cyclin D1 and pRb, were associated with SPA progression. PMID:29344143

A Protein Encoded by the Latency-Related Gene of Bovine Herpesvirus 1 Is Expressed in Trigeminal Ganglionic Neurons of Latently Infected Cattle and Interacts with Cyclin-Dependent Kinase 2 during Productive Infection

PubMed Central

Jiang, Yunquan; Hossain, Ashfaque; Winkler, Maria Teresa; Holt, Todd; Doster, Alan; Jones, Clinton

1998-01-01

Despite productive viral gene expression in the peripheral nervous system during acute infection, the bovine herpesvirus 1 (BHV-1) infection cycle is blocked in sensory ganglionic neurons and consequently latency is established. The only abundant viral transcript expressed during latency is the latency-related (LR) RNA. LR gene products inhibit S-phase entry, and binding of the LR protein (LRP) to cyclin A was hypothesized to block cell cycle progression. This study demonstrates LRP is a nuclear protein which is expressed in neurons of latently infected cattle. Affinity chromatography indicated that LRP interacts with cyclin-dependent kinase 2 (cdk2)-cyclin complexes or cdc2-cyclin complexes in transfected human cells or infected bovine cells. After partial purification using three different columns (DEAE-Sepharose, Econo S, and heparin-agarose), LRP was primarily associated with cdk2-cyclin E complexes, an enzyme which is necessary for G1-to-S-phase cell cycle progression. During acute infection of trigeminal ganglia or following dexamethasone-induced reactivation, BHV-1 induces expression of cyclin A in neurons (L. M. Schang, A. Hossain, and C. Jones, J. Virol. 70:3807–3814, 1996). Expression of S-phase regulatory proteins (cyclin A, for example) leads to neuronal apoptosis. Consequently, we hypothesize that interactions between LRP and cell cycle regulatory proteins promote survival of postmitotic neurons during acute infection and/or reactivation. PMID:9733854

A protein encoded by the latency-related gene of bovine herpesvirus 1 is expressed in trigeminal ganglionic neurons of latently infected cattle and interacts with cyclin-dependent kinase 2 during productive infection.

PubMed

Jiang, Y; Hossain, A; Winkler, M T; Holt, T; Doster, A; Jones, C

1998-10-01

Despite productive viral gene expression in the peripheral nervous system during acute infection, the bovine herpesvirus 1 (BHV-1) infection cycle is blocked in sensory ganglionic neurons and consequently latency is established. The only abundant viral transcript expressed during latency is the latency-related (LR) RNA. LR gene products inhibit S-phase entry, and binding of the LR protein (LRP) to cyclin A was hypothesized to block cell cycle progression. This study demonstrates LRP is a nuclear protein which is expressed in neurons of latently infected cattle. Affinity chromatography indicated that LRP interacts with cyclin-dependent kinase 2 (cdk2)-cyclin complexes or cdc2-cyclin complexes in transfected human cells or infected bovine cells. After partial purification using three different columns (DEAE-Sepharose, Econo S, and heparin-agarose), LRP was primarily associated with cdk2-cyclin E complexes, an enzyme which is necessary for G1-to-S-phase cell cycle progression. During acute infection of trigeminal ganglia or following dexamethasone-induced reactivation, BHV-1 induces expression of cyclin A in neurons (L. M. Schang, A. Hossain, and C. Jones, J. Virol. 70:3807-3814, 1996). Expression of S-phase regulatory proteins (cyclin A, for example) leads to neuronal apoptosis. Consequently, we hypothesize that interactions between LRP and cell cycle regulatory proteins promote survival of postmitotic neurons during acute infection and/or reactivation.

Cyclin D1 Downregulation Contributes to Anti-Cancer Effect of Isorhapontigenin (ISO) on Human Bladder Cancer Cells

PubMed Central

Fang, Yong; Cao, Zipeng; Hou, Qi; Ma, Chen; Yao, Chunsuo; Li, Jingxia; Wu, Xue-Ru; Huang, Chuanshu

2013-01-01

Isorhapontigenin (ISO) is a new derivative of stilbene compound that was isolated from the Chinese herb Gnetum Cleistostachyum, and has been used for treatment of bladder cancers for centuries. In our current studies, we have explored the potential inhibitory effect and molecular mechanisms underlying ISO anti-cancer effects on anchorage-independent growth of human bladder cancer cell lines. We found that ISO showed a significant inhibitory effect on human bladder cancer cell growth and was accompanied with related cell cycle G0/G1 arrest as well as downregulation of Cyclin D1 expression at the transcriptional level in UMUC3 and RT112 cells. Further studies identified that ISO down-regulated Cyclin D1 gene transcription via inhibition of SP1 transactivation. Moreover, ectopic expression of GFP-Cyclin D1 rendered UMUC3 cells resistant to induction of cell cycle G0/G1 arrest and inhibition of cancer cell anchorage-independent growth by ISO treatment. Together, our studies demonstrate that ISO is an active compound that mediates for Gnetum Cleistostachyum’s induction of cell cycle G0/G1 arrest and inhibition of cancer cell anchorage-independent growth through down-regulating SP1/Cyclin D1 axis in bladder cancer cells. Our studies provide a novel insight into understanding the anti-cancer activity of the Chinese herb Gnetum Cleistostachyum and its isolate ISO. PMID:23723126

Cyclin D1-Cdk4 controls glucose metabolism independently of cell cycle progression.

PubMed

Lee, Yoonjin; Dominy, John E; Choi, Yoon Jong; Jurczak, Michael; Tolliday, Nicola; Camporez, Joao Paulo; Chim, Helen; Lim, Ji-Hong; Ruan, Hai-Bin; Yang, Xiaoyong; Vazquez, Francisca; Sicinski, Piotr; Shulman, Gerald I; Puigserver, Pere

2014-06-26

Insulin constitutes a principal evolutionarily conserved hormonal axis for maintaining glucose homeostasis; dysregulation of this axis causes diabetes. PGC-1α (peroxisome-proliferator-activated receptor-γ coactivator-1α) links insulin signalling to the expression of glucose and lipid metabolic genes. The histone acetyltransferase GCN5 (general control non-repressed protein 5) acetylates PGC-1α and suppresses its transcriptional activity, whereas sirtuin 1 deacetylates and activates PGC-1α. Although insulin is a mitogenic signal in proliferative cells, whether components of the cell cycle machinery contribute to its metabolic action is poorly understood. Here we report that in mice insulin activates cyclin D1-cyclin-dependent kinase 4 (Cdk4), which, in turn, increases GCN5 acetyltransferase activity and suppresses hepatic glucose production independently of cell cycle progression. Through a cell-based high-throughput chemical screen, we identify a Cdk4 inhibitor that potently decreases PGC-1α acetylation. Insulin/GSK-3β (glycogen synthase kinase 3-beta) signalling induces cyclin D1 protein stability by sequestering cyclin D1 in the nucleus. In parallel, dietary amino acids increase hepatic cyclin D1 messenger RNA transcripts. Activated cyclin D1-Cdk4 kinase phosphorylates and activates GCN5, which then acetylates and inhibits PGC-1α activity on gluconeogenic genes. Loss of hepatic cyclin D1 results in increased gluconeogenesis and hyperglycaemia. In diabetic models, cyclin D1-Cdk4 is chronically elevated and refractory to fasting/feeding transitions; nevertheless further activation of this kinase normalizes glycaemia. Our findings show that insulin uses components of the cell cycle machinery in post-mitotic cells to control glucose homeostasis independently of cell division.

Adenovirus small interfering RNA targeting ezrin induces apoptosis and inhibits metastasis of human osteosarcoma MG-63 cells.

PubMed

Tao, Zhi-Wei; Zou, Ping-An

2018-06-13

Osteosarcoma is a disease prone to recurrence and metastasis, and adenovirus expression vector is frequently studied as a therapeutic target of osteosarcoma in recent year. This study attempts to explore the effect of adenovirus-mediated small interfering RNA (siRNA) targeting ezrin on the proliferation, migration, invasion and apoptosis of human osteosarcoma MG-63 cells. Human osteosarcoma MG-63 cell line was selected for construction of recombinant adenovirus vector. The mRNA and protein levels of ezrin, Bcl2-associated X protein (Bax), B cell lymphoma-2 (Bcl-2), p21, p53, Caspase-3, matrix metalloproteinase 2 (MMP-2) and MMP-9, Cyclin D1, and cyclin-dependent kinase 4a (CDK4a) were determined. Through ELISA, the levels of Caspase-3, MMP-2 and MMP-9 were examined. Finally, human osteosarcoma MG-63 cell viability, growth, invasion, migration, and apoptosis were detected. Initially, adenovirus expression vector of ezrin was constructed by ezrin 2 siRNA sequence. Adenovirus-mediated siRNA targeting ezrin reduced expression of ezrin in MG-63 cells. The results revealed that adenovirus-mediated siRNA targeting ezrin elevated expression levels of Bax, P21, P53, and Caspase-3, Cyclin D1, and CDK4a and reduced expression levels of Bcl-2, MMP-2, and MMP-9. Furthermore, adenovirus-mediated siRNA targeting ezrin inhibited human osteosarcoma MG-63 cell viability, growth, invasion, and migration, and promoted apoptosis. Our study demonstrates that adenovirus-mediated siRNA targeting ezrin can induce apoptosis and inhibit the proliferation, migration and invasion of human osteosarcoma MG-63 cells. ©2018 The Author(s).

Xanthorrhizol, a natural sesquiterpenoid, induces apoptosis and growth arrest in HCT116 human colon cancer cells.

PubMed

Kang, You-Jin; Park, Kwang-Kyun; Chung, Won-Yoon; Hwang, Jae-Kwan; Lee, Sang Kook

2009-11-01

Xanthorrhizol is a sesquiterpenoid from the rhizome of Curcuma xanthorrhiza. In our previous studies, xanthorrhizol suppressed cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression, inhibited cancer cell growth, and exerted an anti-metastatic effect in an animal model. However, the exact mechanisms for its inhibitory effects against cancer cell growth have not yet been fully elucidated. In the present study, we investigated the growth inhibitory effect of xanthorrhizol on cancer cells. Xanthorrhizol dose-dependently exerted antiproliferative effects against HCT116 human colon cancer cells. Xanthorrhizol also arrested cell cycle progression in the G0/G1 and G2/M phase and induced the increase of sub-G1 peaks. Cell cycle arrest was highly correlated with the downregulation of cyclin A, cyclin B1, and cyclin D1; cyclin-dependent kinase 1 (CDK1), CDK2, and CDK4; proliferating cell nuclear antigen; and inductions of p21 and p27, cyclin-dependent kinase inhibitors. The apoptosis by xanthorrhizol was markedly evidenced by induction of DNA fragmentation, release of cytochrome c, activation of caspases, and cleavage of poly-(ADP-ribose) polymerase. In addition, xanthorrhizol increased the expression and promoter activity of pro-apoptotic non-steroidal anti-inflammatory drug-activated gene-1 (NAG-1). These findings provide one plausible mechanism for the growth inhibitory activity of xanthorrhizol against cancer cells.

Expression of regulatory proteins and proliferative activity in relation to phenotypic characteristics of upper urothelial carcinoma.

PubMed

Dolićanin, Zana; Velicković, Ljubinka Janković; Djordjević, Biljana; Visnjić, Milan; Pesić, Ivana; Ristić, Ana; Marjanović, Vesna

2011-07-01

Deregulation of the normal cell cycle is common in upper urothelial carcinoma (UUC). The aim of this study was to investigate the expression of regulatory proteins of the cell cycle (p53, p16, cyclin D1, HER-2) and proliferative Ki-67 activity in UUC, and to determine their interaction and influence on the phenotypic characteristics of UUC. In 44 patients with UUC, histopathological and immunohistochemical analyses (p53, p16, cyclin D1, HER-2, and Ki-67) of tumors were done. Overexpression/altered expression of p53, p16, cyclin D1 or HER-2 was detected in 20%, 57%, 64%, and 57% of tumors, respectively. Eleven (25%) UUC had a high proliferative Ki-67 index. Forty patients (91%) had at least one marker altered, while four (9%) tumors had a wild-type status. Analysis of relationship between expressions of molecular markers showed that only high expression of p53 was significantly associated with altered p16 activity (p < 0.05). High Ki-67 index was associated with the high stage (p < 0.005), solid growth (p < 0.01), high grade (p < 0.05), and multifocality p < 0.05) of UUC, while high expression of p53 was associated with the solid growth (p < 0.05). In regression models that included all molecular markers and phenotypic characteristics, only Ki-67 correlated with the growth (p < 0.0001), stage (p < 0.01), grade (p < 0.05) and multifocality (p < 0.05) of UCC; (Ki-67 and HER-2 expression correlated with the lymphovascular invasion (p < 0.05). This investigation showed that only negative regulatory proteins of the cell cycle, p53 and p16, were significantly associated in UUC, while proliferative marker Ki-67 was in relation to the key phenotypic characteristics of UUC in the best way.

Anticancer effect of cucurbitacin B on MKN-45 cells via inhibition of the JAK2/STAT3 signaling pathway

PubMed Central

Xie, You-Li; Tao, Wen-Hui; Yang, Ti-Xiong; Qiao, Jian-Guo

2016-01-01

The aim of the present study was to investigate the effect of cucurbitacin B on MKN-45 gastric carcinoma cells. Cell proliferation was determined using a cell counting kit-8 assay, and commercial cell cycle and apoptosis analysis kits were used to determine the cell cycle by flow cytometry. The mRNA expression of genes which mediate cell cycle checkpoints and apoptosis was detected using reverse transcription-quantitative polymerase chain reaction, and a terminal deoxynucleotidyl transferase dUTP nick end labeling assay was used to determine apoptosis rate. Western blot analysis was used to detect the protein expression levels of JAK2/STAT3 signaling pathway-associated proteins. The presented data show that cucurbitacin B significantly inhibited the proliferation of MKN-45 cells in a dose- and time-dependent manner. In accordance with these findings, cucurbitacin B blocked the progression of the cell cycle from G0/G1 to S phase, which was confirmed by the mRNA expression analysis. Cucurbitacin B treatment significantly suppressed the expression of cyclin D1, cyclin E, cyclin-dependent kinase 4 (CDK4) and CDK2, while increasing the expression of p27. Cucurbitacin B also promoted cell apoptosis, as was determined by TUNEL assay and evaluation of mRNA expression. Further experiments suggested that the beneficial effect of cucurbitacin B on blocking the proliferation and inducing the apoptosis of MKN-45 cells may have been associated with suppression of the JAK2/STAT3 signaling pathway. Thus, the present results indicate that cucurbitacin B suppresses proliferation and promoted apoptosis of MKN-45 cells, which may be mediated by inhibition of the JAK2/STAT3 signaling pathway. Cucurbitacin B therefore may warrant further investigation as a feasible therapy for gastric carcinoma. PMID:27698776

A Cyclin D2-derived peptide acts on specific cell cycle phases by activating ERK1/2 to cause the death of breast cancer cells.

PubMed

Russo, Lilian C; Araujo, Christiane B; Iwai, Leo K; Ferro, Emer S; Forti, Fabio L

2017-01-16

Protein degradation by the proteasome generates functional intracellular peptides. Pep5, a peptide derived from Cyclin D2, induces cell death in tumor cell lines and reduces the volume of rat C6 glioblastoma tumors in vivo. Here, we chose the human MDA-MB-231 breast cancer cells to evaluate the mechanism of cell death induced by pep5 in different phases of the cell cycle. Fluorescently labeled pep5, monitored by real time confocal microscopy, entered the MDA-MB-231 cells 3min after application and localized to the nucleus and cytoplasm. Pep5-induced cell death was increased when the MDA-MB-231 cell population was arrested at the G1/S transition or in S phase compared to asynchronous cells. Pep5 induced permanent extracellular signal-regulated kinase (ERK1/2) phosphorylation in MDA-MB-231 cells synchronized in G1/S or S phase. Affinity chromatography followed by mass spectrometry identified CLIC1 and Plectin as the only two proteins that interacted with pep5 in both asynchronous and synchronized MDA-MB-231 cells. These interactions could explain the long-lasting ERK1/2 phosphorylation and the cytoskeleton perturbations in the MDA-MB-231 cells, in which the stress fibers' integrity is affected by pep5 treatments. These data suggest that pep5 has potential therapeutic properties for treating specific types of cancers, such as breast cancer cells. Pep5, a natural intracellular peptide formed by the degradation of Cyclin D2 through the ubiquitin-proteasome system, induces cell death when reintroduced into MDA-MB-231 breast cancer cells, which express low levels of Cyclin D2, specifically in G1/S arrested cells or in cells that are passing through S phase. Under these conditions, pep5 is able to interact with different intracellular proteins, primarily cytoskeleton and proteasome components, which can lead to cellular apoptosis. Together, our data suggest that pep5 is an intracellular peptide with therapeutic potential for treating specific types of tumors with low expression of Cyclin D2 by inhibiting cell proliferation. Copyright © 2016 Elsevier B.V. All rights reserved.

TNF-α sensitizes chemotherapy and radiotherapy against breast cancer cells.

PubMed

Wu, Xiao; Wu, Meng-Yao; Jiang, Min; Zhi, Qiaoming; Bian, Xiaojie; Xu, Meng-Dan; Gong, Fei-Ran; Hou, Juan; Tao, Min; Shou, Liu-Mei; Duan, Weiming; Chen, Kai; Shen, Meng; Li, Wei

2017-01-01

Despite new developments in cancer therapy, chemotherapy and radiotherapy remain the cornerstone of breast cancer treatment. Therefore, finding ways to reduce the toxicity and increase sensitivity is particularly important. Tumor necrosis factor alpha (TNF-α) exerts multiple functions in cell proliferation, differentiation and apoptosis. In the present study, we investigated whether TNF-α could enhance the effect of chemotherapy and radiotherapy against breast cancer cells. Cell growth was determined by MTT assay in vitro, and by using nude mouse tumor xenograft model in vivo. Cell cycle and apoptosis/necrosis were evaluated by flow cytometry. DNA damage was visualized by phospho-Histone H2A.X staining. mRNA expression was assessed by using real-time PCR. Protein expression was tested by Western blot assay. TNF-α strengthened the cytotoxicity of docetaxel, 5-FU and cisplatin against breast cancer cells both in vitro and in vivo. TNF-α activated NF-κB pathway and dependently up-regulated expressions of CyclinD1, CyclinD2, CyclinE, CDK2, CDK4 and CDK6, the key regulators participating in G1→S phase transition. As a result, TNF-α drove cells out of quiescent G0/G1 phase, entering vulnerable proliferating phases. Treatment of TNF-α brought more DNA damage after Cs 137 -irradiation and strengthened G2/M and S phase cell cycle arrest induced by docetaxel and cisplatin respectively. Moreover, the up-regulation of RIP3 (a necroptosis marker) by 5-FU, and the activation of RIP3 by TNF-α, synergistically triggered necroptosis (programmed necrosis). Knockdown of RIP3 attenuated the synergetic effect of TNF-α and 5-FU. TNF-α presented radiotherapy- and chemotherapy-sensitizing effects against breast cancer cells.

Disturbed alternative splicing of FIR (PUF60) directed cyclin E overexpression in esophageal cancers.

PubMed

Ogura, Yukiko; Hoshino, Tyuji; Tanaka, Nobuko; Ailiken, Guzhanuer; Kobayashi, Sohei; Kitamura, Kouichi; Rahmutulla, Bahityar; Kano, Masayuki; Murakami, Kentarou; Akutsu, Yasunori; Nomura, Fumio; Itoga, Sakae; Matsubara, Hisahiro; Matsushita, Kazuyuki

2018-05-01

Overexpression of alternative splicing of far upstream element binding protein 1 (FUBP1) interacting repressor (FIR; poly(U) binding splicing factor 60 [PUF60]) and cyclin E were detected in esophageal squamous cell carcinomas (ESCC). Accordingly, the expression of FBW7 was examined by which cyclin E is degraded as a substrate via the proteasome system. Expectedly, FBW7 expression was decreased significantly in ESCC. Conversely, c-myc gene transcriptional repressor FIR (alias PUF60; U2AF-related protein) and its alternative splicing variant form (FIRΔexon2) were overexpressed in ESCC. Further, anticancer drugs (cis-diaminedichloroplatinum/cisplatin [CDDP] or 5-fluorouracil [5-FU]) and knockdown of FIR by small interfering RNA (siRNA) increased cyclin E while knockdown of FIRΔexon2 by siRNA decreased cyclin E expression in ESCC cell lines (TE1, TE2, and T.Tn) or cervical SCC cells (HeLa cells). Especially, knockdown of SAP155 (SF3b1), a splicing factor required for proper alternative splicing of FIR pre-mRNA, decreased cyclin E. Therefore, disturbed alternative splicing of FIR generated FIR/FIRΔexon2 with cyclin E overexpression in esophageal cancers, indicating that SAP155 siRNA potentially rescued FBW7 function by reducing expression of FIR and/or FIRΔexon2. Remarkably, Three-dimensional structure analysis revealed the hypothetical inhibitory mechanism of FBW7 function by FIR/FIRΔexon2, a novel mechanism of cyclin E overexpression by FIR/FIRΔexon2-FBW7 interaction was discussed. Clinically, elevated FIR expression potentially is an indicator of the number of lymph metastases and anti-FIR/FIRΔexon2 antibodies in sera as cancer diagnosis, indicating chemical inhibitors of FIR/FIRΔexon2-FBW7 interaction could be potential candidate drugs for cancer therapy. In conclusion, elevated cyclin E expression was, in part, induced owing to potential FIR/FIRΔexon2-FBW7 interaction in ESCC.

Maintaining glycogen synthase kinase-3 activity is critical for mTOR kinase inhibitors to inhibit cancer cell growth

PubMed Central

Koo, Junghui; Yue, Ping; Gal, Anthony A.; Khuri, Fadlo R.; Sun, Shi-Yong

2014-01-01

mTOR kinase inhibitors which target both mTORC1 and mTORC2 are being evaluated in cancer clinical trials. Here we report that glycogen synthase kinase-3 (GSK3) is a critical determinant for the therapeutic response to this class of experimental drugs. Pharmacological inhibition of GSK3 antagonized their suppressive effects on the growth of cancer cells similarly to genetic attenuation of GSK3. Conversely, expression of a constitutively activated form of GSK3β sensitized cancer cells to mTOR inhibition. Consistent with these findings, higher basal levels of GSK3 activity in a panel of human lung cancer cell lines correlated with more efficacious responses. Mechanistic investigations showed that mTOR kinase inhibitors reduced cyclin D1 levels in a GSK3β-dependent manner, independent of their effects on suppressing mTORC1 signaling and cap binding. Notably, selective inhibition of mTORC2 triggered proteasome-mediated cyclin D1 degradation, suggesting that mTORC2 blockade is responsible for GSK3-dependent reduction of cyclin D1. Silencing expression of the ubiquitin E3 ligase FBX4 rescued this reduction, implicating FBX4 in mediating this effect of mTOR inhibition. Together, our findings define a novel mechanism by which mTORC2 promotes cell growth, with potential implications for understanding the clinical action of mTOR kinase inhibitors. PMID:24626091

Maintaining glycogen synthase kinase-3 activity is critical for mTOR kinase inhibitors to inhibit cancer cell growth.

PubMed

Koo, Junghui; Yue, Ping; Gal, Anthony A; Khuri, Fadlo R; Sun, Shi-Yong

2014-05-01

mTOR kinase inhibitors that target both mTORC1 and mTORC2 are being evaluated in cancer clinical trials. Here, we report that glycogen synthase kinase-3 (GSK3) is a critical determinant for the therapeutic response to this class of experimental drugs. Pharmacologic inhibition of GSK3 antagonized their suppressive effects on the growth of cancer cells similarly to genetic attenuation of GSK3. Conversely, expression of a constitutively activated form of GSK3β sensitized cancer cells to mTOR inhibition. Consistent with these findings, higher basal levels of GSK3 activity in a panel of human lung cancer cell lines correlated with more efficacious responses. Mechanistic investigations showed that mTOR kinase inhibitors reduced cyclin D1 levels in a GSK3β-dependent manner, independent of their effects on suppressing mTORC1 signaling and cap binding. Notably, selective inhibition of mTORC2 triggered proteasome-mediated cyclin D1 degradation, suggesting that mTORC2 blockade is responsible for GSK3-dependent reduction of cyclin D1. Silencing expression of the ubiquitin E3 ligase FBX4 rescued this reduction, implicating FBX4 in mediating this effect of mTOR inhibition. Together, our findings define a novel mechanism by which mTORC2 promotes cell growth, with potential implications for understanding the clinical action of mTOR kinase inhibitors. ©2014 AACR.

Sox2 acts in a dose-dependent fashion to regulate proliferation of cortical progenitors.

PubMed

Hagey, Daniel W; Muhr, Jonas

2014-12-11

Organ formation and maintenance depends on slowly self-renewing stem cells that supply an intermediate population of rapidly dividing progenitors, but how this proliferative hierarchy is regulated is unknown. By performing genome-wide single-cell and functional analyses in the cortex, we demonstrate that reduced Sox2 expression is a key regulatory signature of the transition between stem cells and rapidly dividing progenitors. In stem cells, Sox2 is expressed at high levels, which enables its repression of proproliferative genes, of which Cyclin D1 is the most potent target. Sox2 confers this function through binding to low-affinity motifs, which facilitate the recruitment of Gro/Tle corepressors in synergy with Tcf/Lef proteins. Upon differentiation, proneural factors reduce Sox2 expression, which derepresses Cyclin D1 and promotes proliferation. Our results show how concentration-dependent Sox2 occupancy of DNA motifs of varying affinities translates into recruitment of repressive complexes, which regulate the proliferative dynamics of neural stem and progenitor cells. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Immunohistochemistry panel segregates molecular types of hepatocellular carcinoma in Brazilian autopsy cases

PubMed Central

Felipe-Silva, Aloísio; Wakamatsu, Alda; dos Santos Cirqueira, Cinthya; Alves, Venâncio Avancini Ferreira

2016-01-01

AIM: To assess the distribution of proteins coded by genes reported as relevant for the molecular classification of hepatocellular carcinoma (HCC). METHODS: In this retrospective cross-sectional study, the following clinicopathological data were analyzed in 80 autopsied HCC patients: sex, age, ethnicity, alcohol intake, infection with hepatitis B and/or C virus, infection with human immunodeficiency virus, prior treatment, basic and immediate causes of death, liver weight, presence of cirrhosis, number and size of nodules, gross pattern, histological grade and variants, architectural pattern, invasion of large veins, and presence and location of extrahepatic metastases. The protein products of genes known to be involved in molecular pathogenesis of HCC, including epidermal growth factor receptor (EGFR), MET, keratin 19 (K19), vimentin, beta-catenin, mechanistic target of rapamycin (mTOR), extracellular signaling-related kinase (ERK)1, ERK2, Ki67, cyclin D1, caspase 3 and p53, were detected by immunohistochemistry on tissue microarrays. The expression levels were scored and statistically assessed for correlation with HCC parameters. RESULTS: Infection with hepatitis C virus was identified in 49% of the 80 autopsy patients, cirrhosis in 90%, advanced tumors in 95%, and extrahepatic metastases in 38%. Expression of K19, p53 and ERK1 correlated to high-grade lesions. Expression of ERK1, nuclear beta-catenin, cyclin D1 and ERK2 correlated to higher rates of cell proliferation as determined by Ki67. Expression of MET, EGFR (> 0) and caspase 3 correlated with lower histological grades. Expression of EGFR correlated to that of caspase 3, and overexpression of EGFR (≥ 200/300) was observed in low-grade tumors more frequently (grades 1 and 2: 67% vs grade 3: 27% and grade 4: 30%). Expression of ERK1 was associated with that of K19 and vimentin, whereas expression of ERK2 was associated with that of cyclin D1, MET and membrane beta-catenin. Expression of vimentin was strongly correlated with that of K19. CONCLUSION: Expression of K19, p53, ERK1, ERK2, vimentin and nuclear beta-catenin was related to higher-grade markers, as opposed to expression/overexpression of EGFR, MET and caspase 3. PMID:27468214

Limb-bud and Heart Overexpression Inhibits the Proliferation and Migration of PC3M Cells.

PubMed

Liu, Qicai; Li, Ermao; Huang, Long; Cheng, Minsheng; Li, Li

2018-01-01

Background: The limb-bud and heart gene ( LBH ) was discovered in the early 21st century and is specifically expressed in the mouse embryonic limb and heart development. Increasing evidences have indicated that LBH not only plays an important role in embryo development, it is also closely correlated with the occurance and progression of many tumors. However, its function in prostate cancer (PCa) is still not well understood. Here, we explored the effects of LBH on the proliferation and migration of the PCa cell line PC3M. Methods: LBH expression in tissues and cell lines of PCa was detected by immunohistochemistry and Western blotting. Lentivirus was used to transduct the LBH gene into the PC3M cells. Stable LBH-overexpressing PC3M-LBH cells and PC3M-NC control cells were obtained via puromycin screening. Cell proliferation was examined using the 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Cell cycle distribution and apoptosis rate were investigated using flow cytometry. Cell migration was studied using the Transwell assay. Results: LBH expression level was down-regulated in 3 different PCa cell lines, especially in PC3M cells, compared with the normal prostate epithelial cells(RWPE-1). Cell lines of LBH-upregulated PC3M-LBH and PC3M-NC control were successfully constructed. Significantly increased LBH expression level and decreased cyclin D1 and cyclin E2 expression level was found in PC3M-LBH cells as compared to the PC3M-NC cells. The overexpression of LBH significantly inhibited PC3M cell proliferation in vitro and tumor growth in nude mice. LBH overexpression in PC3M cell, also induced cell cycle G0/G1 phase arrest and decreased the migration of PC3M cells. Conclusions : Our results reveal that LBH expression is down-regulated in the tissue and cell lines of PCa. LBH overexpression inhibits PC3M cell proliferation and tumor growth by inducing cell cycle arrest through down-regulating cyclin D1and cyclin E2 expression. LBH might be a therapeutic target and potential diagnostic marker in PCa.

The role of metastasis-associated in colon cancer 1 (MACC1) in endometrial carcinoma tumorigenesis and progression.

PubMed

Chen, Shuo; Zong, Zhi-Hong; Wu, Dan-Dan; Sun, Kai-Xuan; Liu, Bo-Liang; Zhao, Yang

2017-04-01

Metastasis-associated in colon cancer-1 (MACC1), has recently been identified as a key regulator in the progression of many cancers. However, its role in endometrial carcinoma (EC) remains unknown. MACC1 expression was determined in EC and normal endometrial tissues by immunohistochemistry. EC cell phenotypes and related molecules were examined after MACC1 downregulation by Small interfering RNA (siRNA) or microRNA (miRNA) transfection. We found that MACC1 was highly expressed in EC tissues than normal samples, and was significantly different in FIGO staging (I and II vs. III and IV), the depth of myometrial infiltration (<1/2 vs. ≥1/2), lymph nodes metastasis (negative vs. positive), besides, MACC1 overexpression was correlated with lower cumulative and relapse-free survival rate. MACC1 downregulation by siRNA transfection significantly induced G1 phrase arrest, suppressed EC cell proliferation, migration, and invasion. In addition, MACC1 downregulation also reduced expression of Cyclin D1 and Cyclin-dependent Kinase 2 (CDK2), N-cadherin (N-Ca), α-SMA, matrix metalloproteinase 2 (MMP2), and MMP9, but increased expression of E-cadherin (E-Ca). Bioinformatic predictions and dual-luciferase reporter assays indicate that MACC1 is a possible target of miR-23b. MiR-23b overexpression reduced MACC1 expression in vitro and induced G1 phrase arrest, suppressed cell proliferation, migration, and invasion. MiR-23b transfection also reduced Cyclin D1 and CDK2, N-Ca, α-SMA, MMP2, MMP9 expression, but increased E-Ca expression. Furthermore, the nude mouse xenograft assay showed that miR-23b overexpression suppressed tumour growth through downregulating MACC1 expression. Taken together, our results demonstrate for the first time that MACC1 may be a new and important diagnosis and therapeutic target of endometrial carcinoma. © 2017 Wiley Periodicals, Inc.

Expression of p21Waf1/Cip1 and cyclin D1 is increased in butyrate-resistant HeLa cells.

PubMed

Derjuga, A; Richard, C; Crosato, M; Wright, P S; Chalifour, L; Valdez, J; Barraso, A; Crissman, H A; Nishioka, W; Bradbury, E M; Th'ng, J P

2001-10-12

Sodium butyrate induced cell cycle arrest in mammalian cells through an increase in p21Waf1/Cip1, although another study showed that this arrest is related to pRB signaling. We isolated variants of HeLa cells adapted to growth in 5 mm butyrate. One of these variants, clone 5.1, constitutively expressed elevated levels of p21Waf1/Cip1 when incubated in regular growth medium and in the presence of butyrate. Despite this elevated level of p21Waf1/Cip1, the cells continue to proliferate, albeit at a slower rate than parental HeLa cells. Western blot analyses showed that other cell cycle regulatory proteins were not up-regulated to compensate for the elevated expression of p21Waf1/Cip1. However, cyclin D1 was down-regulated by butyrate in HeLa cells but not in clone 5.1. We conclude that continued expression of cyclin D1 allowed clone 5.1 to grow in the presence of butyrate and elevated levels of p21Waf1/Cip1.

The integration of HR-HPV increases the expression of cyclins A and E in cytologies with and without low-grade lesions.

PubMed

Zubillaga-Guerrero, M I; Illades-Aguiar, B; Leyva-Vazquez, M A; Flores-Alfaro, E; Castañeda-Saucedo, E; Muñoz-Valle, J F; Alarcón-Romero, L C

2013-01-01

Cyclin-A and cyclin-E are regulators of G1-S phase of normal cell cycle. Integration of human papilloma virus high-risk (HR-HPV) could alter this mechanism, and its overexpression has been associated with poor prognosis in cervical cancer. To determine the expression of cyclin-A and cyclin-E, types of HR-HPV and physical state of DNA in cytologies with the diagnosis of low-grade squamous intraepithelial lesion (LSIL). 115 cytological specimens in liquid base (liquid-PREP(™)) were analyzed. 25 specimens were with no signs of SIL (NSIL) and without HPV; 30 with NSIL with low-risk HPV (LR-HPV); 30 with NSIL with HR-HPV; and 30 with both LSIL and HR-HPV. The expression of cyclins was evaluated by immunocytochemistry; and the detection of viral DNA was done by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLPs) for genotyping or sequencing of HPV. The physical state of HPV was evaluated by in situ hybridization with amplification with tyramide. In the cytologies NSIL with LR-HPV, the expression of cyclin-A and cyclin-E was found respectively in 23.3% and 33.3% of the specimens. Among the specimens of NSIL with HR-HPV, 33.3% expressed cyclin-A and 40% cyclin-E, while 100% of the LSILs expressed the 2 cyclins. On the other hand, 100% of the samples NSIL with LR-HPV presented an episomal pattern. Of the specimens of NSIL with HR-HPV, 56.6% exhibited an episomal pattern, 23.3% integrated and 20%, mixed. Among the LSILs, 90% were mixed and 10% integrated. The cyclins A and E are present in the LSILs that occur predominantly in mixed state in the presence of HR-HPV.

Protective effects of anisodamine on cigarette smoke extract-induced airway smooth muscle cell proliferation and tracheal contractility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Guang-Ni; Yang, Kai; Xu, Zu-Peng

2012-07-01

Anisodamine, an antagonist of muscarinic acetylcholine receptors (mAChRs), has been used therapeutically to improve smooth muscle function, including microvascular, intestinal and airway spasms. Our previous studies have revealed that airway hyper-reactivity could be prevented by anisodamine. However, whether anisodamine prevents smoking-induced airway smooth muscle (ASM) cell proliferation remained unclear. In this study, a primary culture of rat ASM cells was used to evaluate an ASM phenotype through the ability of the cells to proliferate and express contractile proteins in response to cigarette smoke extract (CSE) and intervention of anisodamine. Our results showed that CSE resulted in an increase in cyclinmore » D1 expression concomitant with the G0/G1-to-S phase transition, and high expression of M2 and M3. Functional studies showed that tracheal hyper-contractility accompanied contractile marker α-SMA high-expression. These changes, which occur only after CSE stimulation, were prevented and reversed by anisodamine, and CSE-induced cyclin D1 expression was significantly inhibited by anisodamine and the specific inhibitor U0126, BAY11-7082 and LY294002. Thus, we concluded that the protective and reversal effects and mechanism of anisodamine on CSE-induced events might involve, at least partially, the ERK, Akt and NF-κB signaling pathways associated with cyclin D1 via mAChRs. Our study validated that anisodamine intervention on ASM cells may contribute to anti-remodeling properties other than bronchodilation. -- Highlights: ► CSE induces tracheal cell proliferation, hyper-contractility and α-SMA expression. ► Anisodamine reverses CSE-induced tracheal hyper-contractility and cell proliferation. ► ERK, PI3K, and NF-κB pathways and cyclin D1 contribute to the reversal effect.« less

D-type Cyclins are important downstream effectors of cytokine signaling that regulate the proliferation of normal and neoplastic mammary epithelial cells

PubMed Central

Zhang, Qian; Sakamoto, Kazuhito; Wagner, Kay-Uwe

2013-01-01

In response to the ligand-mediated activation of cytokine receptors, cells decide whether to proliferate or to undergo differentiation. D-type Cyclins (Cyclin D1, D2, or D3) and their associated Cyclin-dependent Kinases (CDK4, CDK6) connect signals from cytokines to the cell cycle machinery, and they propel cells through the G1 restriction point and into the S phase, after which growth factor stimulation is no longer essential to complete cell division. D-type Cyclins are upregulated in many human malignancies including breast cancer to promote an uncontrolled proliferation of cancer cells. After summarizing important aspects of the cytokine-mediated transcriptional regulation and the posttranslational modification of D-type Cyclins, this review will highlight the physiological significance of these cell cycle regulators during normal mammary gland development as well as the initiation and promotion of breast cancer. Although the vast majority of published reports focus almost exclusively on the role of Cyclin D1 in breast cancer, we summarize here previous and recent findings that demonstrate an important contribution of the remaining two members of this Cyclin family, in particular Cyclin D3, for the growth of ErbB2-associated breast cancer cells in humans and in mouse models. New data from genetically engineered models as well as the pharmacological inhibition of CDK4/6 suggest that targeting the combined functions of D-type Cyclins could be a suitable strategy for the treatment of ErbB2-positive and potentially other types of breast cancer. PMID:23562856

Dual Inhibition of Key Proliferation Signaling Pathways in Triple-Negative Breast Cancer Cells by a Novel Derivative of Taiwanin A.

PubMed

Kuo, Yueh-Hsiung; Chiang, En-Pei Isabel; Chao, Che-Yi; Rodriguez, Raymond L; Chou, Pei-Yu; Tsai, Shu-Yao; Pai, Man-Hui; Tang, Feng-Yao

2017-03-01

The treatment of breast cancer cells obtained by blocking the aberrant activation of the proliferation signaling pathways PI3K/Akt/mTOR and MEK/ERK has received considerable attention in recent years. Previous studies showed that Taiwanin A inhibited the proliferation of several types of cancer cells. In this study, we report that 3,4-bis-3,4,5-trimethoxybenzylidene-dihydrofuran (BTMB), a novel derivative of Taiwanin A, significantly inhibited the proliferation of triple-negative breast cancer (TNBC) cells both in vitro and in vivo The results show that BTMB inhibited the proliferation of human TNBC cells by the induction of cell-cycle arrest and apoptosis in a dose-dependent fashion. BTMB inhibited the expression of β-catenin, cdc2 and the cell-cycle regulatory proteins, cyclin A, cyclin D1, and cyclin E. The mechanism of action was associated with the suppression of cell survival signaling through inactivation of the Akt and ERK1/2 signaling pathways. Moreover, BTMB induced cell apoptosis through an increase in the expression of BAX, cleaved caspase-3, and cleaved PARP. Moreover, BTMB inhibited TNBC cell colony formation and sensitized TNBC cells to cisplatin, a chemotherapeutic drug. In a TNBC mouse xenograft model, BTMB significantly inhibited the growth of mammary carcinomas through decreased expression of cyclin D1. BTMB was shown to significantly suppress the growth of mammary carcinoma and therefore to have potential as an anticancer therapeutic agent. Mol Cancer Ther; 16(3); 480-93. ©2016 AACR . ©2016 American Association for Cancer Research.

Overexpression of the Ubiquilin-4 (UBQLN4) is Associated with Cell Cycle Arrest and Apoptosis in Human Normal Gastric Epithelial Cell Lines GES-1 Cells by Activation of the ERK Signaling Pathway

PubMed Central

Huang, Shengkai; Dong, Xin; Wang, Jia; Ding, Jie; Li, Yan; Li, Dongdong; Lin, Hong; Wang, Wenjie; Zhao, Mei

2018-01-01

Background Ubiquilin-4 (UBQLN4) is a component of the ubiquitin-proteasome system and regulates the degradation of many proteins implicated in pathological conditions. The aim of this study was to determine the role of UBQLN4 in regulating the proliferation and survival of the normal gastric epithelial cell line GES-1. Material/Methods We constructed GES-1 lines stably overexpressing UBQLN4 by lentiviral infection. Cell proliferation, apoptosis, and the cell cycle were analyzed using the MTT assay and flow cytometric assays. Phosphorylation of ERK, JNK, p38, and expression of cyclin D1 were detected by western blot analysis. Results Overexpression of UBQLN4 significantly reduced proliferation and induced G2/M phase arrest and apoptosis in GES-1 cells. Moreover, upregulation of UBQLN4 increased the expression of cyclin D1 and phosphorylated ERK, but not JNK or p38. Conclusions These data suggest that UBQLN4 may induce cell cycle arrest and apoptosis via activation of the ERK pathway and upregulation of cyclin D1 in GES-1 cells. PMID:29807370

Altered miRNA expression in aniline-mediated cell cycle progression in rat spleen.

PubMed

Wang, Gangduo; Wang, Jianling; Khan, M Firoze

2017-09-01

Aniline exposure is associated with toxicity to the spleen, however, early molecular events in aniline-induced cell cycle progression in the spleen remain unknown. MicroRNAs (miRNAs) have been implicated in tumor development by modulating key cell cycle regulators and controlling cell proliferation. This study was, therefore, undertaken on the expression of miRNAs, regulation of cyclins and cyclin-dependent kinases (CDKs) in an experimental condition that precedes a tumorigenic response. Male SD rats were treated with aniline (1 mmol/kg/day by gavage) for 7 days, and expression of miRNAs, cyclins and CDKs in rat spleens were analyzed. Microarray and/or qPCR analyses showed that aniline exposure led to significantly decreased miRNA expression of let-7a, miR-24, miR-34c, miR-100, miR-125b, and greatly increased miR-181a. The aberrant expression of miRNAs was associated with significantly increased protein expression of cyclins A, B1, D3 and E. Furthermore, remarkably enhanced expression of CDKs like CDK1, CDK2, CDK4, CDK6, especially p-CDK1 and p-CDK2 as well as alternations in the expression of pRB, p27, and CDC25A in the spleens of aniline-treated rats was also observed. The data suggest that aniline exposure leads to aberrant expression of miRNAs in the spleen which could be important in the regulation of cell cycle proteins. Our findings, thus, provide new insight into the role of miRNAs in cell cycle progression, which may contribute to aniline-induced tumorigenic response in the spleen.

Downregulation of miR-15a due to LMP1 promotes cell proliferation and predicts poor prognosis in nasal NK/T-cell lymphoma.

PubMed

Komabayashi, Yuki; Kishibe, Kan; Nagato, Toshihiro; Ueda, Seigo; Takahara, Miki; Harabuchi, Yasuaki

2014-01-01

Nasal NK/T-cell lymphoma (NNKTL) is an Epstein-Barr virus (EBV)-associated malignancy and has distinct clinical and histological features. However, its genetic features are hitherto unclear. MicroRNAs (miRNAs) play a crucial role in the pathogenesis of several malignancies via regulating gene expression. In this study, we investigated whether the specific microRNAs were related to the tumor behaviors in NNKTL. MiRNA array and Quantitative RT-PCR analyses revealed that miR-15a was expressed at a much lower level in NNKTL cells (SNK-1, SNK-6, and SNT-8) than in normal peripheral NK cells and EBV-negative NK cell line KHYG-1. Quantitative PCR and western blot analyses showed that the expression of MYB and cyclin D1, which are validated targets of miR-15a, was higher in NNKTL cells. Transfection of NNKTL cells (SNK-6 and SNT-8) with a miR-15a precursor decreased MYB and cyclin D1 levels, thereby blocking G1/S transition and cell proliferation. Knockdown of EBV-encoded latent membrane protein 1 (LMP1) significantly increased miR-15a expression in SNK-6 cells. In NNKTL tissues, we found that reduced miR-15a expression, which correlated with MYB and cyclin D1 expression, was associated with poor prognosis of NNKTL patients. These data suggest that downregulation of miR-15a, possibly due to LMP1, implicates in the pathogenesis of NNKTL by inducing cell proliferation via MYB and cyclin D1. Thus, miR-15a could be a potential target for antitumor therapy and a prognostic predictor for NNKTL. Copyright © 2013 Wiley Periodicals, Inc.

Participation of an abnormality in the transforming growth factor-beta signaling pathway in resistance of malignant glioma cells to growth inhibition induced by that factor.

PubMed

Zhang, Lei; Sato, Eiji; Amagasaki, Kenichi; Nakao, Atsuhito; Naganuma, Hirofumi

2006-07-01

Malignant glioma cells secrete and activate transforming growth factor-beta (TGFbeta) and are resistant to growth inhibition by that factor. Nevertheless, the mechanism underlying this effect remains poorly understood. In this study, the mechanism of the resistance to growth inhibition induced by TGFbeta was investigated. The authors examined the expression of downstream components of the TGFbeta receptor, including Smad2, Smad3, Smad4, and Smad7, and the effect of TGFbeta1 treatment on the phosphorylation of Smad2 and the nuclear translocation of Smad2 and Smad3 by using 10 glioma cell lines and the A549 cell line, which is sensitive to TGFbeta-mediated growth inhibition. The expression of two transcriptional corepressor proteins, SnoN and Ski, and the effect of TGFbeta1 treatment on the expression of the SnoN protein and the cell cycle regulators p21, p15, cyclin-dependent kinase-4 (CDK4), and cyclin D1 were also examined. Expression of the Smad2 and Smad3 proteins was lower in the glioma cell lines than in the A549 cell line and in normal astrocytes. In particular, Smad3 expression was low or very low in nine of the 10 malignant glioma cell lines. Expression of Smad4 was low in four glioma cell lines, and expression of the Smad7 protein was similar when compared with protein expression in the A549 cell line and in normal astrocytes. The levels of Smad2 phosphorylation after TGFbeta1 treatment were lower in glioma cell lines than in the A549 cell line, except for one glioma cell line. Seven of the 10 glioma cell lines exhibited lower levels of nuclear translocation of Smad2 and Smad3, and two cell lines that expressed very low levels of Smad3 protein showed no nuclear translocation. All glioma cell lines expressed the SnoN protein and its expression was unaltered by treatment with TGFbeta1. Three glioma cell lines expressed high levels of the Ski protein. The expression of the p21(cip1), p15(INK4B), CDK4, and cyclin D1 proteins was not altered by TGFbeta1, treatment, except in one cell line that displayed a slight increase in p21 protein. Overall, the expression of the Smad2 and Smad3 proteins was low in the glioma cell lines, the phosphorylation and nuclear translocation of Smad2 and Smad3 were impaired, and the TGFbeta receptor signal did not affect the expression of the SnoN, p21, p15, cyclin D1, and CDK4 proteins. These results suggest that the ability to resist TGFbeta-mediated growth inhibition in malignant glioma cells is due to abnormalities in the TGFbeta signaling pathway.

Marine guanidine alkaloids crambescidins inhibit tumor growth and activate intrinsic apoptotic signaling inducing tumor regression in a colorectal carcinoma zebrafish xenograft model.

PubMed

Roel, María; Rubiolo, Juan A; Guerra-Varela, Jorge; Silva, Siguara B L; Thomas, Olivier P; Cabezas-Sainz, Pablo; Sánchez, Laura; López, Rafael; Botana, Luis M

2016-12-13

The marine environment constitutes an extraordinary resource for the discovery of new therapeutic agents. In the present manuscript we studied the effect of 3 different sponge derived guanidine alkaloids, crambescidine-816, -830, and -800. We show that these compounds strongly inhibit tumor cell proliferation by down-regulating cyclin-dependent kinases 2/6 and cyclins D/A expression while up-regulating the cell cyclin-dependent kinase inhibitors -2A, -2D and -1A. We also show that these guanidine compounds disrupt tumor cell adhesion and cytoskeletal integrity promoting the activation of the intrinsic apoptotic signaling, resulting in loss of mitochondrial membrane potential and concomitant caspase-3 cleavage and activation. The crambescidin 816 anti-tumor effect was fnally assayed in a zebrafish xenotransplantation model confirming its potent antitumor activity against colorectal carcinoma in vivo.Considering these results crambescidins could represent promising natural anticancer agents and therapeutic tools.

Marine guanidine alkaloids crambescidins inhibit tumor growth and activate intrinsic apoptotic signaling inducing tumor regression in a colorectal carcinoma zebrafish xenograft model

PubMed Central

Roel, María; Rubiolo, Juan A.; Guerra-Varela, Jorge; Silva, Siguara B. L.; Thomas, Olivier P.; Cabezas-Sainz, Pablo; Sánchez, Laura; López, Rafael; Botana, Luis M.

2016-01-01

The marine environment constitutes an extraordinary resource for the discovery of new therapeutic agents. In the present manuscript we studied the effect of 3 different sponge derived guanidine alkaloids, crambescidine-816, -830, and -800. We show that these compounds strongly inhibit tumor cell proliferation by down-regulating cyclin-dependent kinases 2/6 and cyclins D/A expression while up-regulating the cell cyclin-dependent kinase inhibitors -2A, -2D and -1A. We also show that these guanidine compounds disrupt tumor cell adhesion and cytoskeletal integrity promoting the activation of the intrinsic apoptotic signaling, resulting in loss of mitochondrial membrane potential and concomitant caspase-3 cleavage and activation. The crambescidin 816 anti-tumor effect was fnally assayed in a zebrafish xenotransplantation model confirming its potent antitumor activity against colorectal carcinoma in vivo. Considering these results crambescidins could represent promising natural anticancer agents and therapeutic tools. PMID:27825113

The coffee diterpene kahweol suppresses the cell proliferation by inducing cyclin D1 proteasomal degradation via ERK1/2, JNK and GKS3β-dependent threonine-286 phosphorylation in human colorectal cancer cells.

PubMed

Park, Gwang Hun; Song, Hun Min; Jeong, Jin Boo

2016-09-01

Kahweol as a coffee-specific diterpene has been reported to exert anti-cancer properties. However, the mechanism responsible for the anti-cancer effects of kahweol is not fully understood. The main aim of this investigation was to determine the effect of kahweol on cell proliferation and the possible mechanisms in human colorectal cancer cells. Kahweol inhibited markedly the proliferation of human colorectal cancer cell lines such as HCT116, SW480. Kahweol decreased cyclin D1 protein level in HCT116 and SW480 cells. Contrast to protein levels, cyclin D1 mRNA level and promoter activity did not be changed by kahweol treatment. MG132 treatment attenuated kahweol-mediated cyclin D1 downregulation and the half-life of cyclin D1 was decreased in kahweol-treated cells. Kahweol increased phosphorylation of cyclin D1 at threonine-286 and a point mutation of threonine-286 to alanine attenuated cyclin D1 degradation by kahweol. Inhibition of ERK1/2 by PD98059, JNK by SP600125 or GSK3β by LiCl suppressed cyclin D1 phosphorylation and downregulation by kahweol. Furthermore, the inhibition of nuclear export by LMB attenuated cyclin D1 degradation by kahweol. In conclusion, kahweol-mediated cyclin D1 degradation may contribute to the inhibition of the proliferation in human colorectal cancer cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Effect of sodium phenylbutyrate on the sensitivity of PC3/DTX-resistant prostate cancer cells to docetaxel].

PubMed

Xu, Ya-Wen; Zheng, Shao-Bo; Chen, Bin-Sheng; Wen, Yong; Zhu, Shan-Wen

To investigate the effect of sodium phenylbutyrate (SPB) in modulating docetaxel resistance in human prostate cancer cells in vitro. A PC3/docetaxel-resistant human prostate cancer cell line PC3/DTX was induced and examined for proliferation, viability, and cell inhibition rate in the presence of SPB. The concentration of concentration of docetaxel required to kill 50% of PC3/DTX cells incubated with 0, 1, 2, and 4 mmol/L SPB was determined using MTT assay. Cell apoptosis rate was analyzed with flow cytometry and the cellular expressions of p21, cyclin D1 and survivin proteins were detected using Western blotting. Treatment of PC3/DTX cells with 0, 1, 2, and 4 mmol/L of SPB for 48 h resulted in cell viabilities of (99.85∓2.69)%, (84.68∓3.87)%, (68.65∓4.54)% and (43.54∓5.69)%, and cell inhibition rates of (10.69∓3.65)%, (25.78∓4.58)%, (54.68∓3.98)% and (69.84∓6.54)%, respectively (P<0.05). The concentration of docetaxel required to kill 50% of PC3/DTX cells cultured in the presence of with 0, 1, 2, and 4 mmol/L SPB was 135.98∓2.69, 109.65∓3.87, 87.65∓3.84 and 64.62∓2.98 nmol/L, respectively (P<0.05), and the cell apoptosis rates were (7.2∓0.8)%, (10.2∓0.9)%, (19.8∓2.1)% and (27.4∓2.5)%, respectively. SPB treatment promoted the protein expression of p21 and suppressed the expressions of cyclin D1 and survivin in PC3/DTX cells. SPB can affect the expressions of p21, cyclin D1, and survivin in PC3/DTX cells and increase the sensitivity to the drug-resistant cells to docetaxel.

Structural and functional analysis of cyclin D1 reveals p27 and substrate inhibitor binding requirements.

PubMed

Liu, Shu; Bolger, Joshua K; Kirkland, Lindsay O; Premnath, Padmavathy N; McInnes, Campbell

2010-12-17

An alternative strategy for inhibition of the cyclin dependent kinases (CDKs) in antitumor drug discovery is afforded through the substrate recruitment site on the cyclin positive regulatory subunit. Critical CDK substrates such as the Rb and E2F families must undergo cyclin groove binding before phosphorylation, and hence inhibitors of this interaction also block substrate specific kinase activity. This approach offers the potential to generate highly selective and cell cycle specific CDK inhibitors and to reduce the inhibition of transcription mediated through CDK7 and 9, commonly observed with ATP competitive compounds. While highly potent peptide and small molecule inhibitors of CDK2/cyclin A, E substrate recruitment have been reported, little information has been generated on the determinants of inhibitor binding to the cyclin groove of the CDK4/cyclin D1 complex. CDK4/cyclin D is a validated anticancer drug target and continues to be widely pursued in the development of new therapeutics based on cell cycle blockade. We have therefore investigated the structural basis for peptide binding to its cyclin groove and have examined the features contributing to potency and selectivity of inhibitors. Peptidic inhibitors of CDK4/cyclin D of pRb phosphorylation have been synthesized, and their complexes with CDK4/cyclin D1 crystal structures have been generated. Based on available structural information, comparisons of the cyclin grooves of cyclin A2 and D1 are presented and provide insights into the determinants for peptide binding and the basis for differential binding and inhibition. In addition, a complex structure has been generated in order to model the interactions of the CDKI, p27(KIP)¹, with cyclin D1. This information has been used to shed light onto the endogenous inhibition of CDK4 and also to identify unique aspects of cyclin D1 that can be exploited in the design of cyclin groove based CDK inhibitors. Peptidic and nonpeptidic compounds have been synthesized in order to explore structure-activity relationship for binding to the cyclin D1 groove, which to date has not been carried out in a systematic fashion. Collectively, the data presented provide new insights into how compounds can be developed that function as chemical biology probes to determine the cellular and antitumor effects of CDK inhibition. Furthermore, such compounds will serve as templates for structure-guided efforts to develop potential therapeutics based on selective inhibition of CDK4/cyclin D activity.

Cnidium officinale Makino extract induces apoptosis through activation of caspase-3 and p53 in human liver cancer HepG2 cells

PubMed Central

Hong, Heeok; An, Jeong Cheol; de La Cruz, Joseph F.; Hwang, Seong-Gu

2017-01-01

A number of diverse studies have reported the anticancer properties of Cnidium officinale Makino (CO). However, the apoptotic effect of this traditional medicinal herb in human hepatocellular carcinoma cells (HepG2) remains to be elucidated. Therefore, the present study investigated the ability of CO to reduce cell viability through apoptotic pathways. Cell viability was determined using the 2,3-bis [2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide assay. CO extract-induced apoptosis in HepG2 cells was assessed by Hoechst 33258 staining. The cell cycle was monitored using fluorescence-activated cell sorting analysis with propidium iodide staining. Furthermore, the present study explored whether various signaling molecules associated with HepG2 cell death were affected by CO treatment, including caspase-3, B-cell lymphoma 2 (Bcl-2), tumor protein p53 (p53), cyclin-dependent kinase 4 (CDK4) and cyclin D. The expression levels of these genes were examined by reverse-transcription polymerase chain reaction and western blotting. The expression levels of caspase-3 and p53 were upregulated with CO extract treatment, whereas those of Bcl-2, CDK4 and cyclin D were significantly downregulated. Cleaved caspase-3 expression was upregulated following treatment with CO extract in a dose-dependent manner. Collectively, the data suggest that CO extract has the potential to induce apoptosis of HepG2 cells and may act by suppressing the cell cycle, which leads to caspase-3 cleavage and p53 signaling. PMID:28966688

Analysis of cell cycle-related proteins in gastric intramucosal differentiated-type cancers based on mucin phenotypes: a novel hypothesis of early gastric carcinogenesis based on mucin phenotype

PubMed Central

2010-01-01

Background Abnormalities of cell cycle regulators are common features in human cancers, and several of these factors are associated with the early development of gastric cancers. However, recent studies have shown that gastric cancer tumorigenesis was characterized by mucin expression. Thus, expression patterns of cell cycle-related proteins were investigated in the early phase of differentiated-type gastric cancers to ascertain any mechanistic relationships with mucin phenotypes. Methods Immunostaining for Cyclins D1, A, E, and p21, p27, p53 and β-catenin was used to examine impairments of the cell cycle in 190 gastric intramucosal differentiated-type cancers. Mucin phenotypes were determined by the expressions of MUC5AC, MUC6, MUC2 and CD10. A Ki-67 positive rate (PR) was also examined. Results Overexpressions of p53, cyclin D1 and cyclin A were significantly more frequent in a gastric phenotype than an intestinal phenotype. Cyclin A was overexpressed in a mixed phenotype compared with an intestinal phenotype, while p27 overexpression was more frequent in an intestinal phenotype than in a mixed phenotype. Reduction of p21 was a common feature of the gastric intramucosal differentiated-type cancers examined. Conclusions Our results suggest that the levels of some cell cycle regulators appear to be associated with mucin phenotypes of early gastric differentiated-type cancers. PMID:20525401

Cyclin-dependent kinase inhibitor p21 does not impact embryonic endochondral ossification in mice

PubMed Central

CHINZEI, NOBUAKI; HAYASHI, SHINYA; HASHIMOTO, SHINGO; KANZAKI, NORIYUKI; IWASA, KENJIRO; SAKATA, SHUHEI; KIHARA, SHINSUKE; FUJISHIRO, TAKAAKI; KURODA, RYOSUKE; KUROSAKA, MASAHIRO

2015-01-01

Endochondral ossification at the growth plate is regulated by a number of factors and hormones. The cyclin-dependent kinase inhibitor p21 has been identified as a cell cycle regulator and its expression has been reported to be essential for endochondral ossification in vitro. However, to the best of our knowledge, the function of p21 in endochondral ossification has not been evaluated in vivo. Therefore, the aim of this study was to investigate the function of p21 in embryonic endochondral ossification in vivo. Wild-type (WT) and p21 knockout (KO) pregnant heterozygous mice were sacrificed on embryonic days E13.5, E15.5 and E18.5. Sagittal histological sections of the forearms of the embryos were collected and stained with Safranin O and 5-bromo-2′-deoxyuridine (BrdU). Additionally, the expression levels of cyclin D1, type II collagen, type X collagen, Sox9, and p16 were examined using immunohistochemistry, and the expression levels of p27 were examined using immunofluorescence. Safranin O staining revealed no structural change between the cartilage tissues of the WT and p21KO mice at any time point. Type II collagen was expressed ubiquitously, while type X collagen was only expressed in the hypertrophic zone of the cartilage tissues. No differences in the levels of Sox9 expression were observed between the two groups at any time point. The levels of cyclin D1 expression and BrdU uptake were higher in the E13.5 cartilage tissue compared with those observed in the embryonic cartilage tissue at subsequent time points. Expression of p16 and p27 was ubiquitous throughout the tissue sections. These results indicate that p21 may not be essential for embryonic endochondral ossification in articular cartilage of mice and that other signaling networks may compensate for p21 deletion. PMID:25376471

1α,25 dihydroxi-vitamin D{sub 3} modulates CDK4 and CDK6 expression and localization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Irazoqui, Ana P.; Heim, Nadia B.; Boland, Ricardo L.

We recently reported that the vitamin D receptor (VDR) and p38 MAPK participate in pro-differentiation events triggered by 1α,25(OH){sub 2}-vitamin D{sub 3} [1,25D] in skeletal muscle cells. Specifically, our studies demonstrated that 1,25D promotes G0/G1 arrest of cells inducing cyclin D3 and cyclin dependent kinases inhibitors (CKIs) p21{sup Waf1/Cip1} and p27{sup Kip1} expression in a VDR and p38 MAPK dependent manner. In this work we present data indicating that cyclin-dependent kinases (CDKs) 4 and 6 also play a role in the mechanism by which 1,25D stimulates myogenesis. To investigate VDR involvement in hormone regulation of CDKs 4 and 6, wemore » significantly reduced its expression by the use of a shRNA against mouse VDR, generating the skeletal muscle cell line C2C12-VDR. Investigation of changes in cellular cycle regulating proteins by immunoblotting showed that the VDR is involved in the 1,25D –induced CDKs 4 and 6 protein levels at 6 h of hormone treatment. CDK4 levels remains high during S phase peak and G0/G1 arrest while CDK6 expression decreases at 12 h and increases again al 24 h. The up-regulation of CDKs 4 and 6 by 1,25D (6 h) was abolished in C2C12 cells pre-treated with the ERK1/2 inhibitor, UO126. Moreover, CDKs 4 and 6 expression induced by the hormone nor was detected when α and β isoforms of p38 MAPK were inhibited by compound SB203580. Confocal images show that there is not co-localization between VDR and CDKs at 6 h of hormone treatment, however CDK4 and VDR co-localizates in nucleus after 12 h of 1,25D exposure. Of relevance, at this time 1,25D promotes CDK6 localization in a peri-nuclear ring. Our data demonstrate that the VDR, ERK1/2 and p38 MAPK are involved in the control of CDKs 4 and 6 by 1,25D in skeletal muscle cells sustaining the operation of a VDR and MAPKs –dependent mechanism in hormone modulation of myogenesis. - Highlights: • 1,25D modulates CDKs 4 and 6 expression in skeletal muscle cells. • CDK4 co-localizates with VDR after 1,25D treatment. • CDK6 change its intracellular localization by 1,25D stimulation.« less

Androgen Receptor-Mediated Growth Suppression of HPr-1AR and PC3-Lenti-AR Prostate Epithelial Cells

PubMed Central

Bolton, Eric C.

2015-01-01

The androgen receptor (AR) mediates the developmental, physiologic, and pathologic effects of androgens including 5α-dihydrotestosterone (DHT). However, the mechanisms whereby AR regulates growth suppression and differentiation of luminal epithelial cells in the prostate gland and proliferation of malignant versions of these cells are not well understood, though they are central to prostate development, homeostasis, and neoplasia. Here, we identify androgen-responsive genes that restrain cell cycle progression and proliferation of human prostate epithelial cell lines (HPr-1AR and PC3-Lenti-AR), and we investigate the mechanisms through which AR regulates their expression. DHT inhibited proliferation of HPr-1AR and PC3-Lenti-AR, and cell cycle analysis revealed a prolonged G1 interval. In the cell cycle, the G1/S-phase transition is initiated by the activity of cyclin D and cyclin-dependent kinase (CDK) complexes, which relieve growth suppression. In HPr-1AR, cyclin D1/2 and CDK4/6 mRNAs were androgen-repressed, whereas CDK inhibitor, CDKN1A, mRNA was androgen-induced. The regulation of these transcripts was AR-dependent, and involved multiple mechanisms. Similar AR-mediated down-regulation of CDK4/6 mRNAs and up-regulation of CDKN1A mRNA occurred in PC3-Lenti-AR. Further, CDK4/6 overexpression suppressed DHT-inhibited cell cycle progression and proliferation of HPr-1AR and PC3-Lenti-AR, whereas CDKN1A overexpression induced cell cycle arrest. We therefore propose that AR-mediated growth suppression of HPr-1AR involves cyclin D1 mRNA decay, transcriptional repression of cyclin D2 and CDK4/6, and transcriptional activation of CDKN1A, which serve to decrease CDK4/6 activity. AR-mediated inhibition of PC3-Lenti-AR proliferation occurs through a similar mechanism, albeit without down-regulation of cyclin D. Our findings provide insight into AR-mediated regulation of prostate epithelial cell proliferation. PMID:26372468

Cyclin E-p27 opposition and regulation of the G1 phase of the cell cycle in the murine neocortical PVE: a quantitative analysis of mRNA in situ hybridization

NASA Technical Reports Server (NTRS)

Delalle, I.; Takahashi, T.; Nowakowski, R. S.; Tsai, L. H.; Caviness, V. S. Jr

1999-01-01

We have analyzed the expression patterns of mRNAs of five cell cycle related proteins in the ventricular zone of the neocortical cerebral wall over the course of the neuronogenetic interval in the mouse. One set of mRNAs (cyclin E and p21) are initially expressed at high levels but expression then falls to a low asymptote. A second set (p27, cyclin B and cdk2) are initially expressed at low levels but ascend to peak levels only to decline again. These patterns divide the overall neuronogenetic interval into three phases. In phase 1 cyclin E and p21 levels of mRNA expression are high, while those of mRNAs of p27, cdk2 and cyclin B are low. In this phase the fraction of cells leaving the cycle after each mitosis, Q, is low and the duration of the G1 phase, TG1, is short. In phase 2 levels of expression of cyclin E and p21 fall to asymptote while levels of expression of mRNA of the other three proteins reach their peaks. Q increases to approach 0.5 and TG1 increases even more rapidly to approach its maximum length. In phase 3 levels of expression of cyclin E and p21 mRNAs remain low and those of the mRNAs of the other three proteins fall. TG1 becomes maximum and Q rapidly increases to 1.0. The character of these phases can be understood in part as consequences of the reciprocal regulatory influence of p27 and cyclin E and of the rate limiting functions of p27 at the restriction point and of cyclin E at the G1 to S transition.

Roles of human papillomavirus infection and stathmin in the pathogenesis of sinonasal inverted papilloma.

PubMed

Lin, Hai; Lin, Dong; Xiong, Xi-Sheng

2016-02-01

The purpose of this study was to investigate roles of human papillomavirus (HPV) infection and stathmin in sinonasal inverted papilloma (SNIP). HPV DNA detection was performed by the fluorescence-based polymerase chain reaction (PCR) method. Stathmin protein expression was investigated by the immunohistochemistry method and mRNA expression of stathmin, Kif2a, and cyclin D1 were assessed by real-time PCR in SNIP and control subjects. The positive rate of HPV DNA detected in SNIP was about 53.6% (15 of 28). Recurrent cases showed a higher rate of HPV infection compared with initial cases and higher Krouse stage (T3 + T4) cases showed higher rate of HPV infection than lower Krouse stage (T1 + T2) cases. Stronger expression of stathmin, Kif2a, and cyclin D1 were observed in SNIP, especially HPV(+) SNIP. HPV infection was closely associated with recurrence and progression of SNIP. Stathmin is a valuable prognostic marker and could be considered as a therapeutic target in patients with SNIP. © 2015 Wiley Periodicals, Inc.

NFκB-mediated cyclin D1 expression by microRNA-21 influences renal cancer cell proliferation.

PubMed

Bera, Amit; Ghosh-Choudhury, Nandini; Dey, Nirmalya; Das, Falguni; Kasinath, Balakuntalam S; Abboud, Hanna E; Choudhury, Goutam Ghosh

2013-12-01

MicroRNAs regulate post-transcriptomic landscape in many tumors including renal cell carcinoma. We have recently shown significantly increased expression of miR-21 in renal tumors and that this miRNA contributes to the proliferation of renal cancer cells in culture. However, the mechanism by which miR-21 regulates renal cancer cell proliferation is poorly understood. Addiction to constitutive NFκB activity is hallmark of many cancers including renal cancer. Using miR-21 Sponge in renal cancer cells to block endogenous function of miR-21, we show inhibition of phosphorylation of p65 subunit of NFκB, IKKβ and IκB, which results in attenuation of NFκB transcriptional activity. Subtle reduction in the tumor suppressor PTEN has been linked to various malignancies. We showed previously that miR-21 targeted PTEN in renal cancer cells. Inhibition of PTEN by siRNAs restored miR-21 Sponge-induced suppression of phosphorylation of p65, IKKβ, IκB and NFκB transcriptional activity along with reversal of miR-21 Sponge-reduced phosphorylation of Akt. Expression of constitutively active Akt protected against miR-21 Sponge- and PTEN-mediated decrease in p65/IKKβ/IκB phosphorylation and NFκB transcriptional activity. Furthermore, IKKβ and p65 were required for miR-21-induced renal cancer cell proliferation. Interestingly, miR-21 controlled the expression of cyclin D1 through NFκB-dependent transcription. Finally, we demonstrate that miR-21-regulated renal cancer cell proliferation is mediated by cyclin D1 and CDK4. Together, our results establish a molecular order of a phosphatase-kinase couple involving PTEN/Akt/IKKβ and NFκB-dependent cyclin D1 expression for renal carcinoma cell proliferation by increased miR-21 levels. © 2013.

NFκB-mediated cyclin D1 expression by microRNA-21 influences renal cancer cell proliferation

PubMed Central

Bera, Amit; Ghosh-Choudhury, Nandini; Dey, Nirmalya; Das, Falguni; Kasinath, Balakuntalam S.; Abboud, Hanna E.; Choudhury, Goutam Ghosh

2013-01-01

MicroRNAs regulate post-transcriptomic landscape in many tumors including renal cell carcinoma. We have recently shown significantly increased expression of miR-21 in renal tumors and that this miRNA contributes to the proliferation of renal cancer cells in culture. However, the mechanism by which miR-21 regulates renal cancer cells proliferation is poorly understood. Addiction to constitutive NFκB activity is hallmark of many cancers including renal cancer. Using miR-21 Sponge in renal cancer cells to block endogenous function of miR-21, we show inhibition of phosphorylation of p65 subunit of NFκB, IKKβ and IκB, which results in attenuation of NFκB transcriptional activity. Subtle reduction in the tumor suppressor PTEN has been linked to various malignancies. We showed previously that miR-21 targeted PTEN in renal cancer cells. Inhibition of PTEN by siRNAs restored miR-21 Sponge-induced suppression of phosphorylation of p65, IKKβ, IκB and NFκB transcriptional activity along with reversal of miR-21 Sponge-reduced phosphorylation of Akt. Expression of constitutively active Akt protected against miR-21 Sponge- and PTEN-mediated decrease in p65/IKKβ/IκB phosphorylation and NFκB transcriptional activity. Furthermore, IKKβ and p65 were required for miR-21-induced renal cancer cell proliferation. Interestingly, miR-21 controlled the expression of cyclin D1 through NFκB-dependent transcription. Finally, we demonstrate that miR-21-regulated renal cancer cell proliferation is mediated by cyclin D1 and CDK4. Together, our results establish a molecular order of a phosphatase-kinase couple involving PTEN/Akt/IKKβ and NFκB-dependent cyclin D1 expression for renal carcinoma cell proliferation by increased miR-21 levels. PMID:23981302

The ethanol extract from Artemisia princeps Pampanini induces p53-mediated G1 phase arrest in A172 human neuroblastoma cells.

PubMed

Park, Eun Young; Lee, Kyung-Won; Lee, Heon-Woo; Cho, Young-Wuk; Baek, Nam-In; Chung, Hae-Gon; Jeong, Tae-Sook; Choi, Myung-Sook; Lee, Kyung-Tae

2008-06-01

In the present study, the antiproliferative effects of the ethanol extract of Artemisia princeps Pampanini (EAPP) and the mechanism involved were investigated. Of the various cancer cells examined, human neuroblastoma A172 cells were most sensitive to EAPP, and their proliferation was dose- and time-dependently inhibited by EAPP. DNA flow cytometry analysis indicated that EAPP notably induced the G(1) phase arrest in A172 cells. Of the G(1) phase cycle-related proteins examined, the expressions of cyclin-dependent kinase (CDK) 2, CDK4, and CDK6 and of cyclin D(1), D(2), and D(3) were found to be markedly reduced by EAPP, whereas cyclin E was unaffected. Moreover, the protein and mRNA levels of the CDK inhibitors p16(INK4a), p21(CIP1/WAF1), and p27(KIP1) were increased, and the activities of CDK2, CDK4, and CDK6 were reduced. Furthermore, the expressions of E2F-1 and of phosphorylated pRb were also decreased, and the protein levels of p53 and pp53 (Ser15) were increased. Up-regulation of p21(CIP1/WAF1) was found to be mediated by a p53-dependent pathway in EAPP-induced G(1)-arrested A172 cells. When these data are taken together, the EAPP was found to potently inhibit the proliferation of human neuroblastoma A172 cells via G(1) phase cell cycle arrest.

4-Hydroxytamoxifen-stimulated processing of cyclin E is mediated via G protein-coupled receptor 30 (GPR30) and accompanied by enhanced migration in MCF-7 breast cancer cells.

PubMed

Li, Yang; Chen, Yan; Zhu, Zhu-Xia; Liu, Xiao-Hong; Yang, Li; Wan, Lei; Lei, Ting-Wen; Wang, Xu-Dong

2013-07-05

Over-expression of cleaved cyclin E in breast tumors is closely associated with tumor progression and resistance to antiestrogens. 17β-Estradiol (E2) has been recently shown to induce cyclin E processing in breast cancer cells. Tamoxifen has been used in patients with estrogen-sensitive breast cancer, yet resistance to antiestrogens and recurrence will appear in some of the patients after its continued use. We therefore addressed possible effects of tamoxifen on the generation of cleaved cyclin E and its signal mechanism(s) in estrogen-responsive MCF-7 breast cancer cells that express both G protein-coupled protein (GPR) 30 and estrogen receptor α (ERα). 4-Hydroxytamoxifen (OHT, tamoxifen's active form) failed to prevent E2-induced proteolysis of cyclin E and migration, but rather triggered cyclin E cleavage coincident with augmented migration. OHT-induced cyclin E truncation also occurred in SK-BR-3 cells that express GPR30 and lack ERα, but not in MDA-MB-231 cells that express neither GPR30 nor ERα. G1, a specific GPR 30 agonist, caused dramatic proteolysis of cyclin E and enhanced migration. Furthermore, OHT-stimulated cleavage of cyclin E and migration were tremendously attenuated by G15, a GPR30 antagonist, or siRNA against GPR30. In addition, inhibitors for EGFR or ERK1/2 remarkably suppressed OHT-induced truncation of cyclin E, suggesting involvement of EGFR signaling. Collectively, our data indicate that OHT contributes to the production of proteolyzed cyclin E via GPR30 with augmented migration in MCF-7 cells. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Wnt signaling regulates pancreatic β cell proliferation

PubMed Central

Rulifson, Ingrid C.; Karnik, Satyajit K.; Heiser, Patrick W.; ten Berge, Derk; Chen, Hainan; Gu, Xueying; Taketo, Makoto M.; Nusse, Roel; Hebrok, Matthias; Kim, Seung K.

2007-01-01

There is widespread interest in defining factors and mechanisms that stimulate proliferation of pancreatic islet cells. Wnt signaling is an important regulator of organ growth and cell fates, and genes encoding Wnt-signaling factors are expressed in the pancreas. However, it is unclear whether Wnt signaling regulates pancreatic islet proliferation and differentiation. Here we provide evidence that Wnt signaling stimulates islet β cell proliferation. The addition of purified Wnt3a protein to cultured β cells or islets promoted expression of Pitx2, a direct target of Wnt signaling, and Cyclin D2, an essential regulator of β cell cycle progression, and led to increased β cell proliferation in vitro. Conditional pancreatic β cell expression of activated β-catenin, a crucial Wnt signal transduction protein, produced similar phenotypes in vivo, leading to β cell expansion, increased insulin production and serum levels, and enhanced glucose handling. Conditional β cell expression of Axin, a potent negative regulator of Wnt signaling, led to reduced Pitx2 and Cyclin D2 expression by β cells, resulting in reduced neonatal β cell expansion and mass and impaired glucose tolerance. Thus, Wnt signaling is both necessary and sufficient for islet β cell proliferation, and our study provides previously unrecognized evidence of a mechanism governing endocrine pancreas growth and function. PMID:17404238

TOFA suppresses ovarian cancer cell growth in vitro and in vivo.

PubMed

Li, Shu; Qiu, Lihua; Wu, Buchu; Shen, Haoran; Zhu, Jing; Zhou, Liang; Gu, Liying; Di, Wen

2013-08-01

A characteristic feature of cancer cells is the activation of de novo fatty acid synthesis. Acetyl‑CoA carboxylase (ACC) is a key enzyme in fatty acid synthesis, accelerating the reaction that carboxylates cytosolic acetyl‑CoA to form malonyl‑CoA. ACC is highly expressed in several types of human cancer and is important in breast and prostate cancer cell growth. The aim of the present study was to investigate the effects of 5‑tetradecyloxy‑2‑furoic acid (TOFA), an allosteric inhibitor of ACC, on the proliferation and cell cycle progression of the ovarian cancer cell lines COC1 and COC1/DDP. TOFA was found to be cytotoxic to COC1 and COC1/DDP cells with a 50% inhibitory concentration (IC50) of ~26.1 and 11.6 µg/ml, respectively. TOFA inhibited the proliferation of the cancer cells examined in a time‑ and dose‑dependent manner, arrested the cells in the G0/G1 cell cycle phase and induced apoptosis. The expression of the cell cycle regulating proteins cyclin D1 and cyclin-dependent kinase (CDK) 4, as well as the expression of the apoptosis‑related proteins caspase‑3 and Bcl‑2, were detected by western blot analysis. Cyclin D1, CDK4 and Bcl‑2 protein expression was inhibited by TOFA, while caspase‑3 was cleaved and activated. To the best of our knowledge, the present study demonstrated for the first time that TOFA inhibits COC1/DDP cell growth in ovarian tumor mouse xenografts. By inhibiting ACC, TOFA may be a promising small molecule agent for ovarian cancer therapy.

PM2.5-induced alterations of cell cycle associated gene expression in lung cancer cells and rat lung tissues.

PubMed

Zhao, Hui; Yang, Biao; Xu, Jia; Chen, Dong-Mei; Xiao, Chun-Ling

2017-06-01

The aim of the current study was to investigate the expression of cell cycle-associated genes induced by fine particulate matter (PM 2.5 ) in lung cancer cell line and tissues. The pulmonary lymph node metastasis cells (H292) were treated with PM 2.5 in vitro. Wistar rats were used to perform an in vivo study. Rats were randomly assigned to experiment and control groups and those in the experiment group were exposed to PM 2.5 once every 15 d, while those in the control group were exposed to normal saline. The cell cycle-associated genes expression was analyzed by real-time PCR. Trachea and lung tissues of rats were processed for scanning electron microscopic (SEM) examinations. Exposure of H292 cells to PM 2.5 dramatically increased the expressions of p53 and cyclin-dependent kinase 2 (CDK2) after 24h of exposure (p<0.01) and markedly increased the expressions of the cell division cycle 2 (Cdc2) and cyclin B after 48h of exposure (p<0.01), while those genes expressions were significantly reduced after 72h of exposure, at which time the expression of p21 was predominant (p<0.01). In vivo studies further demonstrated these results. The results of SEM suggested that both of the trachea and lung tissues were damaged and the degree of damage was time-dependent. In conclusion, PM 2.5 can induce significantly alterations of p53 and CDK2 in the early phase, Cdc2 and cyclin B in mid-term and p21 in long-term exposure. The degree of PM 2.5 -induced damage to the trachea and lung tissue was time-dependent. Copyright © 2017. Published by Elsevier B.V.

The inhibitory effects of capillarisin on cell proliferation and invasion of prostate carcinoma cells.

PubMed

Tsui, Ke-Hung; Chang, Ying-Ling; Yang, Pei-Shan; Hou, Chen-Pang; Lin, Yu-Hsiang; Lin, Bing-Wei; Feng, Tsui-Hsia; Juang, Horng-Heng

2018-04-01

Capillarisin (Cap), an active component of Artemisia capillaris root extracts, is characterized by its anti-inflammatory, anti-oxidant and anti-cancer properties. Nevertheless, the functions of Cap in prostate cancer have not been fully explored. We evaluated the potential actions of Cap on the cell proliferation, migration and invasion of prostate carcinoma cells. Cell proliferation and cell cycle distribution were measured by water-soluble tetrazolium-1 and flow cytometry assays. The expression of cyclins, p21, p27, survivin, matrix metallopeptidase (MMP2 and MMP9) were assessed by immunoblotting assays. Effects of Cap on invasion and migration were determined by wound closure and matrigel transmigration assays. The constitutive and interlukin-6 (IL-6)-inducible STAT3 activation of prostate carcinoma cells were determined by immunoblotting and reporter assays. Capillarisin inhibited androgen-independent DU145 and androgen-dependent LNCaP cell growth through the induction of cell cycle arrest at the G0/G1 phase by upregulating p21 and p27 while downregulating expression of cyclin D1, cyclin A and cyclin B. Cap decreased protein expression of survivin, MMP-2, and MMP-9 and therefore blocked the migration and invasion of DU145 cells. Cap suppressed constitutive and IL-6-inducible STAT3 activation in DU145 and LNCaP cells. Our data indicate that Cap blocked cell growth by modulation of p21, p27 and cyclins. The inhibitory effects of Cap on survivin, MMP-2, MMP-9 and STAT3 activation may account for the suppression of invasion in prostate carcinoma cells. Our data suggest that Cap might be a therapeutic agent in treating advanced prostate cancer with constitutive STAT3 or IL-6-inducible STAT3 activation. © 2017 John Wiley & Sons Ltd.

Subchronic exposure to arsenic through drinking water alters expression of cancer-related genes in rat liver.

PubMed

Cui, Xing; Li, Song; Shraim, Amjad; Kobayashi, Yayoi; Hayakawa, Toru; Kanno, Sanae; Yamamoto, Megumi; Hirano, Seishiro

2004-01-01

Although arsenic exposure causes liver disease and/or hepatoma, little is known about molecular mechanisms of arsenic-induced liver toxicity or carcinogenesis. We investigated the effects of arsenic on expression of cancer-related genes in a rat liver following subchronic exposure to sodium arsenate (1, 10, 100 ppm in drinking water), by using real-time quantitative RT-PCR and immunohistochemical analyses. Arsenic accumulated in the rat liver dose-dependently and caused hepatic histopathological changes, such as disruption of hepatic cords, sinusoidal dilation, and fatty infiltration. A 1-month exposure to arsenic significantly increased hepatic mRNA levels of cyclin D1 (10 ppm), ILK (1 ppm), and p27(Kip1) (10 ppm), whereas it reduced mRNA levels of PTEN (1 ppm) and beta-catenin (100 ppm). In contrast, a 4-month arsenic exposure showed increased mRNA expression of cyclin D1 (100 ppm), ILK (1 ppm), and p27(Kip1) (1 and 10 ppm), and decreased expression of both PTEN and beta-catenin at all 3 doses. An immunohistochemical study revealed that each protein expression accords closely with each gene expression of mRNA level. In conclusion, subchronic exposure to inorganic arsenate caused pathological changes and altered expression of cyclin D1, p27(Kip1), ILK, PTEN, and beta-catenin in the liver. This implies that arsenic liver toxicity involves disturbances of some cancer-related molecules.

Veterinary drug, 17β-trenbolone promotes the proliferation of human prostate cancer cell line through the Akt/AR signaling pathway.

PubMed

Lee, Hee-Seok; Jung, Da-Woon; Han, Songyi; Kang, Hui-Seung; Suh, Jin-Hyang; Oh, Hyun-Suk; Hwang, Myung-Sil; Moon, Guiim; Park, Yooheon; Hong, Jin-Hwan; Koo, Yong Eui

2018-05-01

Trenbolone acetate (TBA) is a synthetic anabolic steroidal growth factor that is used for rapid muscle development in cattle. The absorbed TBA is hydrolyzed to the active form, 17β-trenbolone (17 TB; 17β-hydroxy-estra-4,9,11-trien-3-one) in meat and milk products, which can cause adverse health effects in humans. Similar to 5α-dihydrotestosterone (DHT), 17 TB was reported to exhibit endocrine disrupting effects on animals and humans due to its androgenic effect via binding to the androgen receptor. The purpose of this study is to investigate the molecular mechanism of cell proliferation in prostate cancer (PCa) cells treated with 17 TB. We found that 17 TB induces AR-dependent cell proliferation in the human prostate cancer cell line, 22Rv1 in a concentration dependent manner. Treatment with 17 TB increased the expression of cell cycle regulatory proteins, cyclin D2/CDK-4 and cyclin E/CDK-2, whereas the expression of p27 was down-regulated. Furthermore, phosphorylation of Rb and activation of E2F were also induced, which suggests the activation of cyclin D2/CDK-4 and cyclin E/CDK-2 in the cells. When 22Rv1 cells were exposed to 30 pM of 17 TB, which is the effective concentration (EC 50 ) value required to observe proliferative effects on 22Rv1 cells, the expression levels of the phosphorylated forms of Akt and GSK3β were increased. This study demonstrates that 17 TB induces AR-dependent proliferation through the modulation of cell cycle-related proteins in the Akt signaling pathway. The present study provides an effective methodology for identifying cell proliferation signaling of veterinary drugs that exert AR agonistic effects. Copyright © 2018 Elsevier Ltd. All rights reserved.

Adenovirus-mediated tissue factor pathway inhibitor gene transfer induces apoptosis by blocking the phosphorylation of JAK-2/STAT-3 pathway in vascular smooth muscle cells.

PubMed

Fu, Yu; Zhao, Yong; Liu, Yue; Zhu, Yejing; Chi, Jinyu; Hu, Jing; Zhang, Xiaohui; Yin, Xinhua

2012-10-01

In our previous study, we have demonstrated that tissue factor pathway inhibitor (TFPI) gene could induce vascular smooth muscle cell (VSMC) apoptosis. This study was conducted to investigate whether the overexpression of the TFPI gene can induce VSMC apoptosis by inhibiting JAK-2/STAT-3 pathway phosphorylation and thereby inhibiting the expression of such downstream targets as the apoptotic protein Bcl-2 and cell cycle protein cyclin D1. The effect of TFPI on the expression of survivin, a central molecule in cell survival, was also investigated. Rat VSMCs were infected with recombinant adenovirus containing either the TFPI (Ad-TFPI) or LacZ (Ad-LacZ) gene or DMEM in vitro. TFPI expression was detected by ELISA. TUNEL staining and electron microscope were carried out to determine the apoptosis of VSMCs. The expression levels of JAK-2, p-JAK-2, STAT-3, p-STAT-3, cyclin D1, Bcl-2 and survivin were examined by western blot analysis. TFPI protein was detected in the TFPI group after gene transfer and the peak expression was at the 3rd day. At the 3rd, 5th and 7th days after gene transfer, the apoptotic rates by TUNEL assay in the TFPI group were 10.91 ± 1.66%, 13.46 ± 1.28% and 17.04 ± 1.95%, respectively, whereas those in the LacZ group were 3.28 ± 0.89%, 4.01 ± 0.72% and 4.89 ± 1.17%, respectively. We observed cell contraction, slight mitochondrial swelling, nuclear pyknosis and apoptotic body formation in TFPI-treated VSMCs using electron microscopy. JAK-2, p-JAK-2, STAT-3, p-STAT-3, cyclin D1 and Bcl-2, which are all involved in the JAK-2/STAT-3 pathway, were detected in the VSMCs on the 3rd, 5th and 7th days after gene transfer, which is consistent with previously demonstrated time points when VSMCs apoptosis occurred. The expression levels of p-JAK-2, p-STAT-3, cyclin D1 and Bcl-2 were significantly decreased over time in the TFPI group (each P<0.05) but not in the Ad-LacZ and DMEM groups. However, this attenuation of expression was not observed for JAK-2 and STAT-3 in any of the groups at any time points after gene transfer (each P>0.05). The expression level of survivin in the TFPI group also weakened significantly over time compared with the levels in the Ad-LacZ and DMEM groups (each P<0.05) at the 3rd, 5th and 7th days after gene transfer. The results demonstrated that TFPI played an apoptosis-inducing role in VSMCs in a manner that involves both the suppression of JAK-2/STAT-3 pathway phosphorylation and the down-regulation of survivin. Our data show for the first time that targeting the JAK-2/STAT-3 pathway and survivin by overexpressing TFPI may be a new avenue for the treatment of restenosis. Copyright © 2012 Elsevier Inc. All rights reserved.

Overexpression of SASH1 related to the decreased invasion ability of human glioma U251 cells.

PubMed

Yang, Liu; Liu, Mei; Gu, Zhikai; Chen, Jianguo; Yan, Yaohua; Li, Jian

2012-12-01

The purpose of this study was to investigate the impact of SAM- and SH3-domain containing 1 (SASH1) on the biological behavior of glioma cells, including its effects on cellular growth, proliferation, apoptosis, invasion, and metastasis, and thereby to provide an experimental basis for future therapeutic treatments. A pcDNA3.1-SASH1 eukaryotic expression vector was constructed and transfected into the U251 human glioma cell line. Using the tetrazolium-based colorimetric (MTT) assay, flow cytometry analyses, transwell invasion chamber experiments, and other methods, we examined the impact of SASH1 on the biological behaviors of U251 cells, including effects on viability, cell cycle, apoptosis, and invasion. Furthermore, the effect of SASH1 on the expression of cyclin D1, caspase-3, matrix metalloproteinase (MMP)-2, MMP-9, and other proteins was observed. Compared to the empty vector and blank control groups, the pcDNA3.1-SASH1 group of U251 cells exhibited significantly reduced cell viability, proliferation, and invasion (p < 0.05), although there was no difference between the empty vector and blank control groups. The pcDNA3.1-SASH1 group demonstrated a significantly higher apoptotic index than did the empty vector and blank control groups (p < 0.05), and the percentage of apoptotic cells was similar between the empty vector and blank control groups. In addition, the pcDNA3.1-SASH1 group expressed significantly lower protein levels of cyclin D1 and MMP-2/9 compared to the control and empty vector groups (p < 0.05) and significantly higher protein levels of caspase-3 than the other two groups (p < 0.05). Cyclin D1, caspase-3, and MMP-2/9 expression was unchanged between the empty vector and blank control groups. SASH1 gene expression might be related to the inhibition of the growth, proliferation, and invasion of U251 cells and the promotion of U251 cells apoptosis.

Inhibitor of DNA binding 1 regulates cell cycle progression of endothelial progenitor cells through induction of Wnt2 expression

PubMed Central

Xia, Xi; Yu, Yang; Zhang, Li; Ma, Yang; Wang, Hong

2016-01-01

Endothelial injury is a risk factor for atherosclerosis. Endothelial progenitor cell (EPC) proliferation contributes to vascular injury repair. Overexpression of inhibitor of DNA binding 1 (Id1) significantly promotes EPC proliferation; however, the underlying molecular mechanism remains to be fully elucidated. The present study investigated the role of Id1 in cell cycle regulation of EPCs, which is closely associated with proliferation. Overexpression of Id1 increased the proportion of EPCs in the S/G2M phase and significantly increased cyclin D1 expression levels, while knockdown of Id1 arrested the cell cycle progression of EPCs in the G1 phase and inhibited cyclin D1 expression levels. In addition, it was demonstrated that Id1 upregulated wingless-type mouse mammary tumor virus integration site family member 2 (Wnt2) expression levels and promoted β-catenin accumulation and nuclear translocation. Furthermore, Wnt2 knockdown counteracted the effects of Id1 on cell cycle progression of EPCs. In conclusion, the results of the present study indicate that Id1 promoted Wnt2 expression, which accelerated cell cycle progression from G1 to S phase. This suggests that Id1 may promote cell cycle progression of EPCs, and that Wnt2 may be important in Id1 regulation of the cell cycle of EPCs. PMID:27432753

Identification and characterization of an alternative splice variant of Mpl with a high affinity for TPO and its activation of ERK1/2 signaling.

PubMed

Wang, Qiong; Sun, Rui; Wu, Leyan; Huang, Junfeng; Wang, Ping; Yuan, Hailong; Qiu, Feifei; Xu, Xiaohong; Wu, Di; Yu, Ying; Liu, Xin; Zhang, Qing

2013-12-01

The thrombopoietin receptor is a crucial element in thrombopoietin-initiated signaling pathways, which stimulates the differentiation of normal hematopoietic progenitor cells, the maturation of megakaryocytes, and the generation of platelets. In this study, we identified a novel activating variant of thrombopoietin receptor, termed Mpl-D, in human megakaryoblastic leukemia Dami cells and demonstrated that the binding affinity of the Mpl-D receptor for thrombopoietin is enhanced. Cell cycle analysis revealed that in the presence of thrombopoietin, most Mpl-D expressing NIH3T3 (NIH3T3/Mpl-D) cells were prevalent in G1 phase while the S and G2/M populations were less frequently observed. Unexpectedly, thrombopoietin induced strong and prolonged ERK1/2 signaling in NIH3T3/Mpl-D cells compared with its receptor wild-type expressing NIH3T3 (NIH3T3/Mpl-F) cells. Further analysis of the mRNA levels of cyclin D1/D2 in NIH3T3/Mpl-D cells demonstrated markedly down-regulated expression compared to NIH3T3/Mpl-F cells in the presence of thrombopoietin. Thus, the prolonged activation of ERK1/2 by Mpl-D might lead to G1 cell cycle arrest through a profound reduction of cyclin D1/D2 in order to support cell survival without proliferation. We also provided tertiary structural basis for the Mpl-D and thrombopoietin interaction, which might provide insights into how Mpl-D effectively increases binding to thrombopoietin and significantly contributes to its specific signaling pathway. These results suggest a new paradigm for the regulation of cytokine receptor expression and function through the alternative splicing variant of Mpl in Dami cells, which may play a role in the pathogenesis of megakaryoblastic leukemia. Copyright © 2013 Elsevier Ltd. All rights reserved.

Cyclin D1 down-regulation is essential for DBC2's tumor suppressor function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoshihara, Takashi; Collado, Denise; Hamaguchi, Masaaki

2007-07-13

The expression of tumor suppressor gene DBC2 causes certain breast cancer cells to stop growing [M. Hamaguchi, J.L. Meth, C. Von Klitzing, W. Wei, D. Esposito, L. Rodgers, T. Walsh, P. Welcsh, M.C. King, M.H. Wigler, DBC2, a candidate for a tumor suppressor gene involved in breast cancer, Proc. Natl. Acad. Sci. USA 99 (2002) 13647-13652]. Recently, DBC2 was found to participate in diverse cellular functions such as protein transport, cytoskeleton regulation, apoptosis, and cell cycle control [V. Siripurapu, J.L. Meth, N. Kobayashi, M. Hamaguchi, DBC2 significantly influences cell cycle, apoptosis, cytoskeleton, and membrane trafficking pathways. J. Mol. Biol. 346more » (2005) 83-89]. Its tumor suppression mechanism, however, remains unclear. In this paper, we demonstrate that DBC2 suppresses breast cancer proliferation through down-regulation of Cyclin D1 (CCND1). Additionally, the constitutional overexpression of CCND1 prevented the negative impact of DBC2 expression on their growth. Under a CCND1 promoter, the expression of CCNE1 exhibited the same protective effect. Our results indicate that the down-regulation of CCND1 is an essential step for DBC2's growth suppression of cancer cells. We believe that this discovery contributes to a better understanding of DBC2's tumor suppressor function.« less

[Effect of forced E-cadherin expression on adhesion and proliferation of human breast carcinoma cells].

PubMed

Yang, Li-Juan; Liu, Yu-Qin; Gu, Bei; Bian, Xiao-Cui; Feng, Hai-Liang; Yang, Zhen-Li; Liu, Yan-Yan

2010-12-01

To investigate the role that E-cadherin (E-cad) plays on cell adhesion and proliferation of human breast carcinoma. E-cad expression vector was transfected into an E-cad-negative human breast carcinoma MDA-MB-231 cells. G418 was used to screen positive clones. E-cad, β-catenin (β-cat) and cyclin D1 expressions of these clones were confirmed by Western blot. Their cell-cell and cell-matrix adhesion abilities were detected. E-cad/β-catenin interaction was confirmed by immunoprecipitation. Cell proliferation was evaluated by MTT. Cell apoptosis was analyzed by flow cytometry. Direct two-step immunocytochemistry was used to detect the localization of β-cat. E-cad(+) cell strains Ecad-231-7 and Ecad-231-9 were established. When cultured in ultra-low-binding dishes Ecad-231 cells grow in suspension while Ecad-231-7 and Ecad-231-9 cells grow in large clamps. When co-cultured with HCT116 cells, the average adhesion rates at 30 min are 39.0%, 60.0% and 59.5% for MDA-MB-231, Ecad-231-7 and Ecad-231-9 respectively. The average detachment rates by EDTA for 5 min are 37.4%, 4.2% and 7.4% respectively. So E-cad expression enhanced hemotypic and heterotypic cell-cell adhesion and cell-matrix adhesion. Forced exogenously expressed E-cad could combine with endogenous β-cat, whereas down stream cyclin D1 expression was significantly decreased, as evidenced by Western blot. The rates of cell apoptosis of MDA-MB-231, Ecad-231-7 and Ecad-231-9 were 1.8%, 2.0% and 2.1%. Expression of E-cad had no obvious effect on the apoptosis of tumor cells with regular culture. β-cat increased in the cytoplasma. Two monoclonal tumor cell strains (Ecad-231-7 and Ecad-231-9) stably expressing E-cad were successfully established. E-cad could enhance adhesion and inhibit proliferation of human breast carcinoma cells through a pathway involving β-cat and cyclin D1.

Cyclin D1 in well differentiated thyroid tumour of uncertain malignant potential.

PubMed

Lamba Saini, Monika; Weynand, Birgit; Rahier, Jacques; Mourad, Michel; Hamoir, Marc; Marbaix, Etienne

2015-04-18

Encapsulated follicular tumours with equivocal papillary thyroid carcinoma (PTC) type nuclear features continue to remain a challenge despite the recent attempts to classify these borderline lesions. The term 'well differentiated tumour of uncertain malignant potential (WDT-UMP)' was introduced to classify these tumours. The present study aimed to evaluate the role of a cell cycle regulator like cyclin D1 in these tumours along with assessment of other well established PTC markers like galectin-3, HBME-1, CK19. Thirteen cases of metastatic PTC, papillary microcarcinoma and follicular variant of PTC (FVPTC) were identified from a histological review of 510 cases. In addition, 13 cases of a subset of follicular adenomatoid nodules with focal areas showing nuclear features characteristic of PTC, identified as WDT-UMP, were also analyzed. Immunohistochemical analysis of galectin-3, HBME-1, CK19 and the proliferation markers Ki67 and cyclin D1 was performed. Lesions were analyzed for cyclin D1 gene amplification by fluorescent in-situ hybridization. All WDT-UMP lesions showed immunolabelling of cyclin D1, Ki67; 11/ 13 cases showed immunolabelling of CK19; 10/13 cases showed immunolabelling of HBME-1 and 4/13 cases showed immunolabelling of galectin-3. Surrounding benign adenomatoid areas showed no to faint focal staining in all thirteen cases of cyclin D1, HBME-1 and galectin-3. A low rate of cyclin D1 gene amplification was identified in a significant proportion of cells in the WDT-UMP lesions as compared to surrounding benign adenomatoid areas. Increased expression of cyclin D1 and amplification of its gene along with immunolabelling of HBME-1 in WDT-UMP lesions showing cytological features of papillary thyroid carcinoma within follicular adenomatoid nodules suggest that these areas could correspond to a precursor lesion of follicular variant of PTC. Overexpression of cyclin D1, associated with the amplification of the gene suggests that these WDT-UMP lesions are an intermediate between the benign and malignant groups making this group of lesions a reliable precursor of FVPTC. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1851820807142117.

17β-Estradiol Induces Overproliferation in Adenomyotic Human Uterine Smooth Muscle Cells of the Junctional Zone Through Hyperactivation of the Estrogen Receptor-Enhanced RhoA/ROCK Signaling Pathway.

PubMed

Sun, Fu-Qing; Duan, Hua; Wang, Sha; Li, Jin-Jiao

2015-11-01

Adenomyosis (ADS) is a common estrogen-dependent gynecological disease with unknown etiology. Recent models favor abnormal thickening of the junctional zone (JZ) may be the causative factor in the development of ADS. RhoA, a small guanosine triphosphatase which controls multiple cellular processes, is involved in the control of cell proliferation. Here we demonstrate that treatment of human uterine smooth muscle cells (SMCs) of the JZ with 17β-estradiol (E2) increased expression of RhoA and its downstream effectors (-associated coiled coil containing protein kinase [ROCK] 1 and ROCK2). Compared with non-ADS cells, RhoA, ROCK1, and ROCK2 were overexpressed and hyperactivated in ADS cells. These effects were suppressed in the presence of ICI 182,780, supporting an estrogen receptor (ER)-dependent mechanism. Hyperactivation of ER-enhanced RhoA/ROCK signaling was associated with overproliferation in ADS human uterine SMCs of the JZ. Moreover, E2-induced overproliferation was accompanied by downregulation of cyclin-dependent kinases inhibitors (CKIs; p21(Waf1/Cip1) and p27(Kip1)) and upregulation of cyclin-dependent kinases (CDKs) and cyclins (cyclin D1, cyclin E1, CDK2, CDK4, and CDK6). © The Author(s) 2015.

High cyclin A expression, but not Ki67, is associated with early recurrence in desmoid tumors.

PubMed

Santti, Kirsi; Ihalainen, Hanna; Rönty, Mikko; Böhling, Tom; Karlsson, Christina; Haglund, Caj; Tarkkanen, Maija; Blomqvist, Carl

2018-06-07

Desmoid tumors are soft-tissue tumors originating from myofibroblasts with a tendency to recur after surgery. High expression of proliferation markers is associated with shortened progression-free and/or overall survival in many neoplasms, including soft-tissue sarcomas. We investigated the prognostic role of cyclin A and Ki67 in desmoid tumors by immunohistochemistry. The study included 76 patients with desmoid tumor operated at Helsinki University Hospital between 1987 and 2011. A tissue micro array (TMA) was constructed and the TMA sections were immunostained with cyclin A and Ki67 antibodies. A computer-assisted image analysis was performed. Cyclin A expression was evaluable in 74 and Ki67 in 70 patients. Cyclin A immunopositivity varied from 0% to 9.9%, with a mean of 1.9%. Cyclin A expression correlated significantly with Ki67. Cyclin A expression was associated with recurrence-free survival (HR 1.9, 95% CI = 1.1-3.2, P = .02), as were positive margin (HR 6.0, 95% CI = 1.6-22.5, P = .008) and extremity location (HR 5.3, 95% CI = 1.7-16.8, P = 0.005). Ki67 immunopositivity varied from 0.33% to 13.8%, with a mean of 4.6%, but had no significant prognostic impact (HR 1.1, P = .2). Our study indicates that cyclin A may be a new prognostic biomarker in surgically treated desmoid tumors. © 2018 Wiley Periodicals, Inc.

Genetic characterization of the role of the Cip/Kip family of proteins as cyclin-dependent kinase inhibitors and assembly factors.

PubMed

Cerqueira, Antonio; Martín, Alberto; Symonds, Catherine E; Odajima, Junko; Dubus, Pierre; Barbacid, Mariano; Santamaría, David

2014-04-01

The Cip/Kip family, namely, p21(Cip1), p27(Kip1), and p57(Kip2), are stoichiometric cyclin-dependent kinase inhibitors (CKIs). Paradoxically, they have been proposed to also act as positive regulators of Cdk4/6-cyclin D by stabilizing these heterodimers. Loss of p21(Cip1) and p27(Kip1) reduces Cdk4/6-cyclin D complexes, although with limited phenotypic consequences compared to the embryonic lethality of Cdk4/6 or triple cyclin D deficiency. This milder phenotype was attributed to Cdk2 compensatory mechanisms. To address this controversy using a genetic approach, we generated Cdk2(-/-) p21(-/-) p27(-/-) mice. Triple-knockout mouse embryonic fibroblasts (MEFs) displayed minimal levels of D-type cyclins and Cdk4/6-cyclin D complexes. p57(Kip2) downregulation in the absence of p21(Cip1) and p27(Kip1) aggravated this phenotype, yet MEFs lacking all Cip/Kip proteins exhibited increased retinoblastoma phosphorylation, together with enhanced proliferation and transformation capacity. In vivo, Cdk2 ablation induced partial perinatal lethality in p21(-/-) p27(-/-) mice, suggesting partial Cdk2-dependent compensation. However, Cdk2(-/-) p21(-/-) p27(-/-) survivors displayed all phenotypes described for p27(-/-) mice, including organomegalia and pituitary tumors. Thus, Cip/Kip deficiency does not impair interphasic Cdk activity even in the absence of Cdk2, suggesting that their Cdk-cyclin assembly function is dispensable for homeostatic control in most cell types.

Differentiation of C2C12 myoblasts expressing lamin A mutated at a site responsible for Emery-Dreifuss muscular dystrophy is improved by inhibition of the MEK-ERK pathway and stimulation of the PI3-kinase pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Favreau, Catherine; Delbarre, Erwan; Courvalin, Jean-Claude

2008-04-01

Mutation R453W in A-type lamins, that are major nuclear envelope proteins, generates Emery-Dreifuss muscular dystrophy. We previously showed that mouse myoblasts expressing R453W-lamin A incompletely exit the cell cycle and differentiate into myocytes with a low level of multinucleation. Here we attempted to improve differentiation by treating these cells with a mixture of PD98059, an extracellular-regulated kinase (ERK) kinase (also known as mitogen-activated kinase, MEK) inhibitor, and insulin-like growth factor-II, an activator of phosphoinositide 3-kinase. We show that mouse myoblasts expressing R453W-lamin A were sensitive to the drug treatment as shown by (i) an increase in multinucleation, (ii) downregulation ofmore » proliferation markers (cyclin D1, hyperphosphorylated Rb), (iii) upregulation of myogenin, and (iv) sustained activation of p21 and cyclin D3. However, nuclear matrix anchorage of p21 and cyclin D3 in a complex with hypophosphorylated Rb that is critical to trigger cell cycle arrest and myogenin induction was deficient and incompletely restored by drug treatment. As the turn-over of R453W-lamin A at the nuclear envelope was greatly enhanced, we propose that R453W-lamin A impairs the capacity of the nuclear lamina to serve as scaffold for substrates of the MEK-ERK pathway and for MyoD-induced proteins that play a role in the differentiation process.« less

Exisulind in combination with celecoxib modulates epidermal growth factor receptor, cyclooxygenase-2, and cyclin D1 against prostate carcinogenesis: in vivo evidence.

PubMed

Narayanan, Bhagavathi A; Reddy, Bandaru S; Bosland, Maarten C; Nargi, Dominick; Horton, Lori; Randolph, Carla; Narayanan, Narayanan K

2007-10-01

Nonsteroidal anti-inflammatory drugs mediate anticancer effects by modulating cyclooxygenase-2 (COX-2)-dependent and/or COX-2-independent mechanism(s); however, the toxicity issue is a concern with single agents at higher doses. In this study, we determined the combined effect of celecoxib, a COX-2 inhibitor, along with exisulind (sulindac sulfone/Aptosyn) at low doses in prostate cancer. We used a sequential regimen of N-methyl-N-nitrosourea + testosterone to induce prostate cancer in Wistar-Unilever rats. Following carcinogen treatment, celecoxib and exisulind individually and their combination at low doses were given in NIH-07 diet for 52 weeks. We determined the incidence of prostatic intraepithelial neoplasia, adenocarcinomas, rate of tumor cell proliferation, and apoptosis. Immunohistochemical and Western blot analysis were done to determine COX-2, epidermal growth factor receptor (EGFR), Akt, androgen receptor, and cyclin D1 expression. Serum prostaglandin E2 and tumor necrosis factor-alpha levels were determined using enzyme immunoassay/ELISA assays. The rats that received celecoxib in combination with exisulind at low doses showed a significant decrease in prostatic intraepithelial neoplasia and adenocarcinomas as well as an enhanced rate of apoptosis. An overall decrease in COX-2, EGFR, Akt, androgen receptor, and cyclin D1 expression was found associated with tumor growth inhibition. Reduced serum levels of COX-2 protein, prostaglandin E2, and tumor necrosis factor-alpha indicated anti-inflammatory effects. A strong inhibition of total and phosphorylated form of EGFR (Tyr(992) and Tyr(845)) and Akt (Ser(473)) was significant in rats given with these agents in combination. In this study, we show for the first time that the combination of celecoxib with exisulind at low doses could prevent prostate carcinogenesis by altering key molecular events.

Ghrelin augments murine T-cell proliferation by activation of the phosphatidylinositol-3-kinase, extracellular signal-regulated kinase and protein kinase C signaling pathways

PubMed Central

Lee, Jun Ho; Patel, Kalpesh; Tae, Hyun Jin; Lustig, Ana; Kim, Jie Wan; Mattson, Mark P.; Taub, Dennis D.

2014-01-01

Thymic atrophy occurs during normal aging, and is accelerated by exposure to chronic stressors that elevate glucocorticoid levelsand impair the naïve T cell output. The orexigenic hormone ghrelin was recently shown to attenuate age-associated thymic atrophy. Here, we report that ghrelin enhances the proliferation of murine CD4+ primary T cells and a CD4+ T-cell line. Ghrelin induced activation of the ERK1/2 and Akt signaling pathways, via upstream activation of phosphatidylinositol-3-kinase and protein kinase C, to enhance T-cell proliferation. Moreover, ghrelin induced expression of the cell cycle proteins cyclin D1, cyclin E, cyclin-dependent kinase 2 (CDK2) and retinoblastoma phosphorylation. Finally, ghrelin activated the above-mentioned signaling pathways and stimulated thymocyte proliferation in young and older mice in vivo. PMID:25447526

Synergistic cardioprotective effects of rAAV9-CyclinA2 combined with fibrin glue in rats after myocardial infarction.

PubMed

Cao, Wen; Chang, Ya-Fei; Zhao, Ai-Chao; Chen, Bang-Dang; Liu, Fen; Ma, Yi-Tong; Ma, Xiang

2017-08-01

The present study aimed to investigate the protective effects of rAAV9-CyclinA2 combined with fibrin glue (FG) in vivo in rats after myocardial infarction (MI). Ninety male Sprague-Dawley rats were randomized into 6 groups (15 in each group): sham, MI, rAAV9-green fluorescent protein (GFP) + MI, rAAV9-CyclinA2 + MI, FG + MI, and rAAV9-CyclinA2 + FG + MI. Packed virus (5 × 10 11 vg/ml) in 150 µl of normal saline or FG was injected into the infarcted myocardium at five locations in rAAV9-GFP + MI, rAAV9-CyclinA2 + MI, and rAAV9-CyclinA2 + FG + MI groups. The sham, MI, and FG + MI groups were injected with an equal volume of normal saline or FG at the same sites. Five weeks after injection, echocardiography was performed to evaluate the left ventricular function. The expressions of CyclinA2, proliferating cell nuclear antigen (PCNA), and phospho-histone-H3 (H3P), vascular density, and infarct area were assessed by Western blot, immunohistochemistry, immunofluorescence, and Masson staining. As a result, the combination of rAAV9-CyclinA2 and FG increased ejection fraction and fractional shortening compared with FG or rAAV9-CyclinA2 alone. The expression level of CyclinA2 was significantly higher in the rAAV9-CyclinA2 + FG + MI group compared with the rAAV9-CyclinA2 + MI and FG + MI groups (70.1 ± 1.86% vs. 14.74 ± 2.02%, P < 0.01; or vs. 50.13 ± 3.80%; P < 0.01). A higher expression level of PCNA and H3P was found in the rAAV9-CyclinA2 + FG + MI group compared with other groups. Comparing with other experiment groups, collagen deposition and the infarct size significantly decreased in rAAV9-CyclinA2 + Fibrin + MI group. The vascular density was much higher in the rAAV9-CyclinA2 + FG + MI group compared with the rAAV9-CyclinA2 + MI group. We concluded that fibrin glue combined with rAAV9-CyclinA2 was found to be effective in cardiac remodeling and improving myocardial protection.

The Concerted Action of Type 2 and Type 3 Deiodinases Regulates the Cell Cycle and Survival of Basal Cell Carcinoma Cells.

PubMed

Miro, Caterina; Ambrosio, Raffaele; De Stefano, Maria Angela; Di Girolamo, Daniela; Di Cicco, Emery; Cicatiello, Annunziata Gaetana; Mancino, Giuseppina; Porcelli, Tommaso; Raia, Maddalena; Del Vecchio, Luigi; Salvatore, Domenico; Dentice, Monica

2017-04-01

Thyroid hormones (THs) mediate pleiotropic cellular processes involved in metabolism, cellular proliferation, and differentiation. The intracellular hormonal environment can be tailored by the type 1 and 2 deiodinase enzymes D2 and D3, which catalyze TH activation and inactivation respectively. In many cellular systems, THs exert well-documented stimulatory or inhibitory effects on cell proliferation; however, the molecular mechanisms by which they control rates of cell cycle progression have not yet been entirely clarified. We previously showed that D3 depletion or TH treatment influences the proliferation and survival of basal cell carcinoma (BCC) cells. Surprisingly, we also found that BCC cells express not only sustained levels of D3 but also robust levels of D2. The aim of the present study was to dissect the contribution of D2 to TH metabolism in the BCC context, and to identify the molecular changes associated with cell proliferation and survival induced by TH and mediated by D2 and D3. We used the CRISPR/Cas9 technology to genetically deplete D2 and D3 in BCC cells and studied the consequences of depletion on cell cycle progression and on cell death. Cell cycle progression was analyzed by fluorescence activated cell sorting analysis of synchronized cells, and the apoptosis rate by annexin V incorporation. Mechanistic investigations revealed that D2 inactivation accelerates cell cycle progression thereby enhancing the proportion of S-phase cells and cyclin D1 expression. Conversely, D3 mutagenesis drastically suppressed cell proliferation and enhanced apoptosis of BCC cells. Furthermore, the basal apoptotic rate was oppositely regulated in D2- and D3-depleted cells. Our results indicate that BCC cells constitute an example in which the TH signal is finely tuned by the concerted expression of opposite-acting deiodinases. The dual regulation of D2 and D3 expression plays a critical role in cell cycle progression and cell death by influencing cyclin D1-mediated entry into the G1-S phase. These findings reinforce the concept that TH is a potential therapeutic target in human BCC.

Minute Virus of Mice Inhibits Transcription of the Cyclin B1 Gene during Infection.

PubMed

Fuller, Matthew S; Majumder, Kinjal; Pintel, David J

2017-07-15

Replication of minute virus of mice (MVM) induces a sustained cellular DNA damage response (DDR) which the virus then exploits to prepare the nuclear environment for effective parvovirus takeover. An essential aspect of the MVM-induced DDR is the establishment of a potent premitotic block, which we previously found to be independent of activated p21 and ATR/Chk1 signaling. This arrest, unlike others reported previously, depends upon a significant, specific depletion of cyclin B1 and its encoding RNA, which precludes cyclin B1/CDK1 complex function, thus preventing mitotic entry. We show here that while the stability of cyclin B1 RNA was not affected by MVM infection, the production of nascent cyclin B1 RNA was substantially diminished at late times postinfection. Ectopic expression of NS1 alone did not reduce cyclin B1 expression. MVM infection also reduced the levels of cyclin B1 protein, and RNA levels normally increased in response to DNA-damaging reagents. We demonstrated that at times of reduced cyclin B1 expression during infection, there was a significantly reduced occupancy of RNA polymerase II and the essential mitotic transcription factor FoxM1 on the cyclin B1 gene promoter. Additionally, while total FoxM1 levels remained constant, there was a significant decrease of the phosphorylated, likely active, forms of FoxM1. Targeting of a constitutively active FoxM1 construct or the activation domain of FoxM1 to the cyclin B1 gene promoter via clustered regularly interspaced short palindromic repeats (CRISPR)-enzymatically inactive Cas9 in MVM-infected cells increased both cyclin B1 protein and RNA levels, implicating FoxM1 as a critical target for cyclin B1 inhibition during MVM infection. IMPORTANCE Replication of the parvovirus minute virus of mice (MVM) induces a sustained cellular DNA damage response (DDR) which the virus exploits to prepare the nuclear environment for effective takeover. An essential aspect of the MVM-induced DDR is establishment of a potent premitotic block. This block depends upon a significant, specific depletion of cyclin B1 and its encoding RNA that precludes cyclin B1/CDK1 complex functions necessary for mitotic entry. We show that reduced cyclin B1 expression is controlled primarily at the level of transcription initiation. Additionally, the essential mitotic transcription factor FoxM1 and RNA polymerase II were found to occupy the cyclin B1 gene promoter at reduced levels during infection. Recruiting a constitutively active FoxM1 construct or the activation domain of FoxM1 to the cyclin B1 gene promoter via CRISPR-catalytically inactive Cas9 (dCas9) in MVM-infected cells increased expression of both cyclin B1 protein and RNA, implicating FoxM1 as a critical target mediating MVM-induced cyclin B1 inhibition. Copyright © 2017 American Society for Microbiology.

Minute Virus of Mice Inhibits Transcription of the Cyclin B1 Gene during Infection

PubMed Central

Fuller, Matthew S.; Majumder, Kinjal

2017-01-01

ABSTRACT Replication of minute virus of mice (MVM) induces a sustained cellular DNA damage response (DDR) which the virus then exploits to prepare the nuclear environment for effective parvovirus takeover. An essential aspect of the MVM-induced DDR is the establishment of a potent premitotic block, which we previously found to be independent of activated p21 and ATR/Chk1 signaling. This arrest, unlike others reported previously, depends upon a significant, specific depletion of cyclin B1 and its encoding RNA, which precludes cyclin B1/CDK1 complex function, thus preventing mitotic entry. We show here that while the stability of cyclin B1 RNA was not affected by MVM infection, the production of nascent cyclin B1 RNA was substantially diminished at late times postinfection. Ectopic expression of NS1 alone did not reduce cyclin B1 expression. MVM infection also reduced the levels of cyclin B1 protein, and RNA levels normally increased in response to DNA-damaging reagents. We demonstrated that at times of reduced cyclin B1 expression during infection, there was a significantly reduced occupancy of RNA polymerase II and the essential mitotic transcription factor FoxM1 on the cyclin B1 gene promoter. Additionally, while total FoxM1 levels remained constant, there was a significant decrease of the phosphorylated, likely active, forms of FoxM1. Targeting of a constitutively active FoxM1 construct or the activation domain of FoxM1 to the cyclin B1 gene promoter via clustered regularly interspaced short palindromic repeats (CRISPR)-enzymatically inactive Cas9 in MVM-infected cells increased both cyclin B1 protein and RNA levels, implicating FoxM1 as a critical target for cyclin B1 inhibition during MVM infection. IMPORTANCE Replication of the parvovirus minute virus of mice (MVM) induces a sustained cellular DNA damage response (DDR) which the virus exploits to prepare the nuclear environment for effective takeover. An essential aspect of the MVM-induced DDR is establishment of a potent premitotic block. This block depends upon a significant, specific depletion of cyclin B1 and its encoding RNA that precludes cyclin B1/CDK1 complex functions necessary for mitotic entry. We show that reduced cyclin B1 expression is controlled primarily at the level of transcription initiation. Additionally, the essential mitotic transcription factor FoxM1 and RNA polymerase II were found to occupy the cyclin B1 gene promoter at reduced levels during infection. Recruiting a constitutively active FoxM1 construct or the activation domain of FoxM1 to the cyclin B1 gene promoter via CRISPR-catalytically inactive Cas9 (dCas9) in MVM-infected cells increased expression of both cyclin B1 protein and RNA, implicating FoxM1 as a critical target mediating MVM-induced cyclin B1 inhibition. PMID:28446681

c-Jun induces apoptosis of starved BM2 monoblasts by activating cyclin A-CDK2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vanhara, Petr; Bryja, Vitezslav; Horvath, Viktor

2007-02-02

c-Jun is one of the major components of the activating protein-1 (AP-1), the transcription factor that participates in regulation of proliferation, differentiation, and apoptosis. In this study, we explored functional interactions of the c-Jun protein with several regulators of the G1/S transition in serum-deprived v-myb-transformed chicken monoblasts BM2. We show that the c-Jun protein induces expression of cyclin A, thus up-regulating activity of cyclin A-associated cyclin-dependent kinase 2 (CDK2), and causing massive programmed cell death of starved BM2cJUN cells. Specific inhibition of CDK2 suppresses frequency of apoptosis of BM2cJUN cells. We conclude that up-regulation of cyclin A expression and CDK2more » activity can represent important link between the c-Jun protein, cell cycle machinery, and programmed cell death pathway in leukemic cells.« less

The G1/S Specific Cyclin D2 Is a Regulator of HIV-1 Restriction in Non-proliferating Cells

PubMed Central

Badia, Roger; Pujantell, Maria; Riveira-Muñoz, Eva; Puig, Teresa; Torres-Torronteras, Javier; Martí, Ramón; Clotet, Bonaventura; Ampudia, Rosa M.; Ballana, Ester

2016-01-01

Macrophages are a heterogeneous cell population strongly influenced by differentiation stimuli that become susceptible to HIV-1 infection after inactivation of the restriction factor SAMHD1 by cyclin-dependent kinases (CDK). Here, we have used primary human monocyte-derived macrophages differentiated through different stimuli to evaluate macrophage heterogeneity on cell activation and proliferation and susceptibility to HIV-1 infection. Stimulation of monocytes with GM-CSF induces a non-proliferating macrophage population highly restrictive to HIV-1 infection, characterized by the upregulation of the G1/S-specific cyclin D2, known to control early steps of cell cycle progression. Knockdown of cyclin D2, enhances HIV-1 replication in GM-CSF macrophages through inactivation of SAMHD1 restriction factor by phosphorylation. Co-immunoprecipitation experiments show that cyclin D2 forms a complex with CDK4 and p21, a factor known to restrict HIV-1 replication by affecting the function of the downstream cascade that leads to SAMHD1 deactivation. Thus, we demonstrate that cyclin D2 acts as regulator of cell cycle proteins affecting SAMHD1-mediated HIV-1 restriction in non-proliferating macrophages. PMID:27541004

Novel taspine derivative 12k inhibits cell growth and induces apoptosis in lung cell carcinoma.

PubMed

Dai, Bingling; Wang, Wenjie; Liu, Rui; Wang, Hongying; Zhang, Yanmin

2015-03-01

Taspine is an active compound in anticancer agent development. 12k was synthesized with taspine as lead compound bearing biphenyl scaffold and showed potent anticancer activity. Here, we investigated the effect of taspine derivative 12k on A549 lung cells. We showed that 12k not only decreased significantly A549 cell viability, A549 cell colony formation but also impaired A549 cell migration. Moreover, 12k treatment blocked cell cycle progression by increasing cell number in S phase to 42.80% for 6 μmol/L vs. 28.86% for control while decreasing cell number in G1 phase. Accordingly, this was associated with an increase protein expression of cyclin E and a decrease protein expression of cyclin D1, cyclin B1 and its associated CDK1 (cdc2). Meanwhile, we found that 12k induced A549 cell apoptosis, which was closely associated with the effect of the Bcl-2 family. Increase of Bad, Bak and Bax expression levels, decrease of Bcl-2 and Mcl-1 expression levels were observed. SiRNA knockdown of c-myc in A549 cells significantly attenuated tumor inhibition effects of 12k. In conclusion, our results demonstrate that 12k has an inhibitory effect on growth of A549 cell by inducing cell cycle arrest and apoptosis. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

α-Phellandrene alters expression of genes associated with DNA damage, cell cycle, and apoptosis in murine leukemia WEHI-3 cells.

PubMed

Lin, Jen-Jyh; Yu, Chien-Chih; Lu, Kung-Wen; Chang, Shu-Jen; Yu, Fu-Shun; Liao, Ching-Lung; Lin, Jaung-Geng; Chung, Jing-Gung

2014-08-01

α-phellandrene (α-PA) is a cyclic monoterpene, present in natural plants such as Schinus molle L. α-PA promotes immune responses in mice in vivo. However, there is no available information on whether α-PA affects gene expression in leukemia cells. The present study determined effects of α-PA on expression levels of genes associated with DNA damage, cell cycle and apoptotic cell death in mouse leukemia WEHI-3 cells. WEHI-3 cells were treated with 10 μM α-PA for 24 h, cells were harvested and total RNA was extracted, and gene expression was analyzed by cDNA microarray. Results indicated that α-PA up-regulated 10 genes 4-fold, 13 by over 3-fold and 175 by over 2-fold; 21 genes were down-regulated by over 4-fold, 26 genes by over 3-fold and expression of 204 genes was altered by at leas 2-fold compared with the untreated control cells. DNA damage-associated genes such as DNA damage-inducer transcript 4 and DNA fragmentation factor were up-regulated by 4-fold and over 2-fold, respectively; cell-cycle check point genes such as cyclin G2 and cyclin-dependent kinases inhibitor 2D and IA (p21) were up-regulated by over 3-fold and over 2-fold, respectively; apoptosis-associated genes such as BCL2/adenovirus EIB interacting protein 3, XIAP-associated factor 1, BCL2 modifying factor, caspase-8 and FADD-like apoptosis regulator were over 2-fold up-regulated. Furthermore, DNA damage-associated gene TATA box binding protein was over 4-fold down-regulated, and D19Ertd652c (DNA segment) over 2-fold down-regulated; cell cycle-associated gene cyclin E2 was over 2-fold down-regulated; apoptosis associated gene growth arrest-specific 5 was over 9-fold down-regulated, Gm5426 (ATP synthase) was over 3-fold down-regulated, and death box polypeptide 33 was over 2-fold down-regulated. Based on these observations, α-PA altered gene expression in WEHI-3 cells in vitro. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Ran GTPase protein promotes human pancreatic cancer proliferation by deregulating the expression of Survivin and cell cycle proteins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deng, Lin; Department of Oncology, Tangdu Hospital, Fourth Military Medical University, Xi’an, Shaanxi 710038; Lu, Yuanyuan

2013-10-18

Highlights: •Overexpression of Ran in pancreatic cancer was correlated with histological grade. •Downregulation of Ran could induce cell apoptosis and inhibit cell proliferation. •The effects were mediated by cell cycle proteins, Survivin and cleaved Caspase-3. -- Abstract: Ran, a member of the Ras GTPase family, has important roles in nucleocytoplasmic transport. Herein, we detected Ran expression in pancreatic cancer and explored its potential role on tumour progression. Overexpressed Ran in pancreatic cancer tissues was found highly correlated with the histological grade. Downregulation of Ran led to significant suppression of cell proliferation, cell cycle arrest at the G1/S phase and inductionmore » of apoptosis. In vivo studies also validated that result. Further studies revealed that those effects were at least partly mediated by the downregulation of Cyclin A, Cyclin D1, Cyclin E, CDK2, CDK4, phospho-Rb and Survivin proteins and up regulation of cleaved Caspase-3.« less

The PP2A-B56 Phosphatase Opposes Cyclin E Autocatalytic Degradation via Site-Specific Dephosphorylation

PubMed Central

Davis, Ryan J.; Swanger, Jherek; Hughes, Bridget T.

2017-01-01

ABSTRACT Cyclin E, in conjunction with its catalytic partner cyclin-dependent kinase 2 (CDK2), regulates cell cycle progression as cells exit quiescence and enter S-phase. Multiple mechanisms control cyclin E periodicity during the cell cycle, including phosphorylation-dependent cyclin E ubiquitylation by the SCFFbw7 ubiquitin ligase. Serine 384 (S384) is the critical cyclin E phosphorylation site that stimulates Fbw7 binding and cyclin E ubiquitylation and degradation. Because S384 is autophosphorylated by bound CDK2, this presents a paradox as to how cyclin E can evade autocatalytically induced degradation in order to phosphorylate its other substrates. We found that S384 phosphorylation is dynamically regulated in cells and that cyclin E is specifically dephosphorylated at S384 by the PP2A-B56 phosphatase, thereby uncoupling cyclin E degradation from cyclin E-CDK2 activity. Furthermore, the rate of S384 dephosphorylation is high in interphase but low in mitosis. This provides a mechanism whereby interphase cells can oppose autocatalytic cyclin E degradation and maintain cyclin E-CDK2 activity while also enabling cyclin E destruction in mitosis, when inappropriate cyclin E expression is genotoxic. PMID:28137908

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Qingchang; Dong, Qianze; Wang, Enhua, E-mail: wangenhuacmu@hotmail.com

Highlights: Black-Right-Pointing-Pointer Rsf-1 expression is elevated in non-small cell lung cancers. Black-Right-Pointing-Pointer Rsf-1 depletion inhibits proliferation and increased apoptosis in lung cancer cells. Black-Right-Pointing-Pointer Rsf-1 depletion decreases the level of cyclinD1 and phosphor-ERK expression. -- Abstract: Rsf-1 (HBXAP) was recently reported to be overexpressed in various cancers and associated with the malignant behavior of cancer cells. However, the expression of Rsf-1 in primary lung cancer and its biological roles in non-small cell lung cancer (NSCLC) have not been reported. The molecular mechanism of Rsf-1 in cancer aggressiveness remains ambiguous. In the present study, we analyzed the expression pattern of Rsf-1more » in NSCLC tissues and found that Rsf-1 was overexpressed at both the mRNA and protein levels. There was a significant association between Rsf-1 overexpression and TNM stage (p = 0.0220) and poor differentiation (p = 0.0013). Furthermore, knockdown of Rsf-1 expression in H1299 and H460 cells with high endogenous Rsf-1 expression resulted in a decrease of colony formation ability and inhibition of cell cycle progression. Rsf-1 knockdown also induced apoptosis in these cell lines. Further analysis showed that Rsf-1 knockdown decreased cyclin D1 expression and phospho-ERK levels. In conclusion, Rsf-1 is overexpressed in NSCLC and contributes to malignant cell growth by cyclin D1 and ERK modulation, which makes Rsf-1 a candidate therapeutic target in lung cancer.« less

Expression of cyclin D{sub 1} during endotoxin-induced aleveolar type II cell hyperplasia in rat lung and the detection of apoptotic cells during the remodeling process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tesfaigzi, J.; Wood, M.B.; Johnson, N.F.

Our studies have shown that endotoxin intratracheally instilled into the rat lung induces proliferation of alveolar type II cells. In that study, the alveolar type II cells. In that study, the alveolar type II cell hyperplasia occurred 2 d after instillation of endotoxin and persisted for a further 2 d. After hyperplasia, the lung remodeled and returned to a normal state within 24-48 h. Understanding the mechanisms involved in the remodeling process of this transient hyperplasia may be useful to identify molecular changes that are altered in neoplasia. The purpose of the present study was to corroborate induction of epithelialmore » cell hyperplasia by endotoxin and to delineate mechanisms involved in tissue remodeling after endotoxin-induced alveolar type II cell hyperplasia. In conclusion, immonostaining with cyclin D1 and cytokeratin shows that endotoxin induced epithelial cell proliferation and resulted in hyperplasia in the lung which persisted through 4 d post-instillation.« less

Clinicopathological and prognostic significance of cyclin D1 amplification in patients with breast cancer: a meta-analysis.

PubMed

He, Qi; Wu, Jingxun; Liu, Xin-Li; Ma, Yi-Han; Wu, Xiao-Ting; Wang, Wen-Yi; An, Han-Xiang

2017-01-01

Cyclin D1 plays a critical role in tumorigenesis and the regulation of the G1/S transition in the cell cycle. The relationship between cyclin D1 amplification and clinicopathological parameters in patients with breast cancer remains controversial and its impact on survival outcome is not completely clear. We conducted a meta-analysis to investigate the associations between cyclin D1 gene amplification and certain clinicopathological characteristics and the prognosis in breast cancer. Literature search of PubMed (up to August 3, 2016) was performed. We used Stata 12.0 (Stata Corporation, Texas, US) to analyze the correlations between cyclin D1 amplification and clinicopathological features and the prognostic indicator relapse free survival (RFS) and overall survival (OS) in patients with breast cancer. Publication bias analysis and sensitivity analysis were performed. A total of 9,238 breast cancer patients from 21 studies were included. The pooled odds ratios (ORs) indicated that cyclin D1 amplification was significantly associated with estrogen receptor (ER), progesterone receptor (PR), histological grade and lymph node status, but not associated with human epidermal growth factor receptor-2 (HER2) and tumor size. The combined hazard ratios (HRs) for RFS and OS showed that patients with cyclin D1 amplification displayed a 1.31-fold higher risk of recurrence (HR =1.31, 95% confidence interval (95% CI):1.02-1.60, p<0.01), and a risk of mortality 1.22-fold higher times greater than those without cyclin D1 amplification (HR=1.22, 95% CI:0.99- 1.44, p<0.01), respectively. Our meta-analysis indicated that cyclin D1 amplification is significantly associated with established clinicopathological variables and can be used as a poor prognostic indicator for patients with breast cancer.

Preclinical evaluation of destruxin B as a novel Wnt signaling target suppressing proliferation and metastasis of colorectal cancer using non-invasive bioluminescence imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yeh, Chi-Tai; Center of Excellence for Cancer Research, Taipei Medical University, Taipei, Taiwan; Department of Surgery, Taipei Medical University-Shuang Ho Hospital, Taipei, Taiwan

2012-05-15

In continuation to our studies toward the identification of direct anti-cancer targets, here we showed that destruxin B (DB) from Metarhizium anisopliae suppressed the proliferation and induced cell cycle arrest in human colorectal cancer (CRC) HT29, SW480 and HCT116 cells. Additionally, DB induced apoptosis in HT29 cells by decreased expression level of anti-apoptotic proteins Bcl-2 and Bcl-xL while increased pro-apoptotic Bax. On the other hand, DB attenuated Wnt-signaling by downregulation of β-catenin, Tcf4 and β-catenin/Tcf4 transcriptional activity, concomitantly with decreased expression of β-catenin target genes cyclin D1, c-myc and survivin. Furthermore, DB affected the migratory and invasive ability of HT29more » cells through suppressed MMPs-2 and -9 enzymatic activities. We also found that DB targeted the MAPK and/or PI3K/Akt pathway by reduced expression of Akt, IKK-α, JNK, NF-κB, c-Jun and c-Fos while increased that of IκBα. Finally, we demonstrated that DB inhibited tumorigenesis in HT29 xenograft mice using non-invasive bioluminescence technique. Consistently, tumor samples from DB-treated mice demonstrated suppressed expression of β-catenin, cyclin D1, survivin, and endothelial marker CD31 while increased caspase-3 expression. Collectively, our data supports DB as an inhibitor of Wnt/β-catenin/Tcf signaling pathway that may be beneficial in the CRC management. Highlights: ► Destruxin B (DB) inhibited colorectal cancer cells growth and induced apoptosis. ► MAPK and/or PI3K/Akt cascade cooperates in DB induced apoptosis. ► DB affected the migratory and invasive ability of HT29 cells through MMP-9. ► DB attenuated Wnt-signaling components β-catenin, Tcf4. ► DB attenuated cyclin D1, c-myc, survivin and tumorigenesis in HT29 xenograft mice.« less

Piperlongumine decreases cell proliferation and the expression of cell cycle-associated proteins by inhibiting Akt pathway in human lung cancer cells.

PubMed

Seok, Jin Sil; Jeong, Chang Hee; Petriello, Michael C; Seo, Han Geuk; Yoo, Hyunjin; Hong, Kwonho; Han, Sung Gu

2018-01-01

Piperlongumine (PL) is an alkaloid of a pepper plant found in Southeast Asia. PL is known to induce selective toxicity towards a variety of cancer cell types. To explore the possible anti-lung cancer effects of PL, A549 cells were treated with PL (0-40 μM) for 24 h. Alterations in the expression of cell cycle-associated proteins (cyclin D1, cyclin-dependent kinase 4 (CDK4), CDK6 and retinoblastoma (Rb)) and intracellular signaling molecules (extracellular signal receptor-activated kinase 1/2 (ERK1/2), Akt, p38 and nuclear factor-κB (NF-κB)) were examined in cells following treatment of PL using Western blot analysis. Results showed that proliferation of cells were significantly decreased by PL in a dose-dependent manner. Flow cytometry results demonstrated increased number of cells in G1 phase in PL (40 μM)-treated group. Reactive oxygen species was significantly increased in cells treated with PL at 20-40 μM. The expression of cyclin D1, CDK4, CDK6 and p-Rb were markedly decreased in cells treated with PL at 40 μM. Treatment of cells with PL suppressed phosphorylation of Akt but increased ERK1/2 phosphorylation. Treatment of PL significantly decreased nuclear translocation of NF-κB p65 in cells. These results suggest that PL possesses antiproliferative properties in A549 cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rac1b enhances cell survival through activation of the JNK2/c-JUN/Cyclin-D1 and AKT2/MCL1 pathways

PubMed Central

Wang, Hong; Wei, Si-Si; Chen, Jie; Chen, Yi-He; Xu, Wei-Ping; Jie, Qi-Qiang; Zhou, Qing; Li, Yi-Gang; Wei, Yi-Dong; Wang, Yue-Peng

2016-01-01

Rac1b is a constitutively activated, alternatively spliced form of the small GTPase Rac1. Previous studies showed that Rac1b promotes cell proliferation and inhibits apoptosis. In the present study, we used microarray analysis to detect genes differentially expressed in HEK293T cells and SW480 human colon cancer cells stably overexpressing Rac1b. We found that the pro-proliferation genes JNK2, c-JUN and cyclin-D1 as well as anti-apoptotic AKT2 and MCL1 were all upregulated in both lines. Rac1b promoted cell proliferation and inhibited apoptosis by activating the JNK2/c-JUN/cyclin-D1 and AKT2/MCL1 pathways, respectively. Very low Rac1b levels were detected in the colonic epithelium of wild-type Sprague-Dawley rats. Knockout of the rat Rac1 gene exon-3b or knockdown of endogenous Rac1b in HT29 human colon cancer cells downregulated only the AKT2/MCL1 pathway. Our study revealed that very low levels of endogenous Rac1b inhibit apoptosis, while Rac1b upregulation both promotes cell proliferation and inhibits apoptosis. It is likely the AKT2/MCL1 pathway is more sensitive to Rac1b regulation. PMID:26918455

Nuclear accumulation of epidermal growth factor receptor and acceleration of G1/S stage by Epstein-Barr-encoded oncoprotein latent membrane protein 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tao Yongguang; Song Xing; Deng Xiyun

Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) is considered to be the major oncogenic protein of EBV-encoded proteins and has always been the core of the oncogenic mechanism of EBV. Advanced studies on nuclear translocation of the epidermal growth factor receptor (EGFR) family have greatly improved our knowledge of the biological function of cell surface receptors. In this study, we used the Tet-on LMP1 HNE2 cell line as a cell model, which is a dual-stable LMP1-integrated nasopharyngeal carcinoma (NPC) cell line and the expression of LMP1 which could be regulated by the Tet system. We found that LMP1 couldmore » regulate the nuclear accumulation of EGFR in a dose-dependent manner quantitatively and qualitatively. We also demonstrated that the nuclear localization sequence of EGFR played some roles in the location of the protein within the nucleus under LMP1 regulation and EGFR in the nucleus could bind to the promoters of cyclinD1 and cyclinE, respectively. We further demonstrated that EGFR is involved in the acceleration of the G1/S phase transition by LMP1 through binding to cyclinD1 and cyclinE directly. These findings provided a novel view that the acceleration of LMP1 on the G1/S transition via the nuclear accumulation of EGFR was critical in the process of nasopharyngeal carcinoma.« less

Mechanistic insights into avian reovirus p17-modulated suppression of cell-cycle CDK/cyclin complexes and enhancement of p53 and cyclin H interaction.

PubMed

Chiu, Hung-Chuan; Huang, Wei-Ru; Liao, Tsai-Ling; Chi, Pei-I; Nielsen, Brent L; Liu, Jyung-Hurng; Liu, Hung-Jen

2018-06-15

The avian reovirus (ARV) p17 protein is a nucleocytoplasmic shuttling protein. Although we have demonstrated that p17 causes cell growth retardation via activation of p53, the precise mechanisms remains unclear. This is the first report that ARV p17 possesses broad inhibitory effects on cell-cycle CDKs, cyclins, CDK/cyclin complexes, and CDK activating kinase (CAK) activity in various mammalian, avian, and cancer cell lines. Suppression of CDK activity by p17 occurs by direct binding to CDKs, cyclins, and CDK/cyclin complexes, transcriptional downregulation of CDKs, cytoplasmic retention of CDKs and cyclins, and inhibition of CAK activity by promoting p53/cyclin H interaction. p17 binds to CDK/cyclin except for CDK1/cyclin B1 and CDK7/cyclin H complexes. We have determined that the negatively charged 151 LAVxDxDxE/DDGADPN 165 motif in cyclin B1 interacts with a positively charged region of CDK1. p17 mimics the cyclin B1 sequence to compete for CDK1 binding. The PSTAIRE motif is not required for interaction of CDK1/cyclin B1, but is required for other CDK/cyclin complexes. p17 interacts with cyclins by its cyclin-binding motif 125 RXL 127 Sequence and mutagenic analyses of p17 indicated that a 140 WXFD 143 motif and residues D113 and K122 in p17 are critical for CDK2 and CDK6 binding, leading to their sequestration in the cytoplasm. Exogenous expression of p17 significantly enhanced virus replication while p17 mutants with low binding ability to cell-cycle CDKs have no effect on virus yield, suggesting that p17 inhibits cell growth and the cell cycle benefiting virus replication. An in vivo tumorigenesis assay also showed a significant reduction in tumor size. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

Cyclin A1 shows age-related expression in benign tonsils, HPV16-dependent overexpression in HNSCC and predicts lower recurrence rate in HNSCC independently of HPV16

PubMed Central

2012-01-01

Background Promoter methylation of the tumor suppressor gene Cyclin A1 could be associated with Human Papillomavirus 16 (HPV16) induced Head and Neck Squamous Cell Carcinoma (HNSCC) and Cervical Carcinoma. There is disagreement about the impact of this epigenetic event on protein expression of Cyclin A1 in malignant and non-malignant tissue and there hardly exists any information about possible relationships between Cyclin A1 expression and clinicopathological characteristics in HNSCC. Methods We analyzed protein expression of Cyclin A1 in 81 HNSCC and 74 benign tonsils by immunohistochemistry and correlated it to Cyclin A1 methylation status, presence of HPV16 infection and other clinicopathological characteristics. Results Overexpression of Cyclin A1 was more present in HNSCC than in tonsils (p < 0.001). In both entities, HNSCC and benign tonsils, expression of Cyclin A1 significantly correlated with the expression of Cyclin-dependent kinase-inhibitor p16 (p = 0.000672 and 0.00495). In tonsils, expression of Cyclin A1 was inversely proportional to age (p = 0.00000396), and further correlated with expression of tumor suppressor gene p53 (p = 0.000228). In HNSCC Cyclin A1 expression was associated with the presence of HPV16 DNA (p = 0.0014) and a lower recurrence rate in univariate and multivariate analysis (p = 0.002 and 0.013). Neither in HNSCC nor in tonsils Cyclin A1 expression correlated with promoter methylation. Conclusions Cyclin A1 is an important cell cycle regulator with age-related increased expression in tonsils of children. HPV16 induces overexpression of Cyclin A1 in HNSCC despite promoter methylation. Overexpression of Cyclin A1 predicts a lower recurrence rate in HNSCC independently of HPV16. PMID:22712549

Amplification and overexpression of cyclin D1 in breast cancer detected by immunohistochemical staining.

PubMed

Gillett, C; Fantl, V; Smith, R; Fisher, C; Bartek, J; Dickson, C; Barnes, D; Peters, G

1994-04-01

Immunohistochemical staining with a monoclonal antibody against human cyclin D1 can be used to identify breast cancers that have an amplification of the q13 region of chromosome 11. In general, the intensity of staining is directly proportional to the degree of DNA amplification. In two unusual tumors, in which the CCND1 locus is highly amplified but staining is relatively weak, it appears that the DNA has undergone rearrangement and that the amplified/rearranged CCND1 allele may have reduced transcriptional activity. More significantly, the immunohistochemical technique identifies additional tumors in which the cyclin D1 gene is overexpressed with only marginal or undetectable increases in copy number, implying that other mechanisms can lead to deregulated expression. These results suggest that the frequency of overexpression is much higher than previously concluded from DNA-based analyses and that more than one-third of human breast cancers may contain excessive levels of cyclin D1. The technique we describe should facilitate the detection of this abnormality in a clinical setting and clarify its prognostic significance.

Copper Uptake in Mammary Epithelial Cells Activates Cyclins and Triggers Antioxidant Response

PubMed Central

dos Santos, Nathália Villa; Matias, Andreza Cândido; Higa, Guilherme Shigueto Vilar; Kihara, Alexandre Hiroaki; Cerchiaro, Giselle

2015-01-01

The toxicologic effects of copper (Cu) on tumor cells have been studied during the past decades, and it is suggested that Cu ion may trigger antiproliferative effects in vitro. However, in normal cells the toxicologic effects of high exposures of free Cu are not well understood. In this work, Cu uptake, the expression of genes associated with cell cycle regulation, and the levels of ROS production and related oxidative processes were evaluated in Cu-treated mammary epithelial MCF10A nontumoral cells. We have shown that the Cu additive is associated with the activation of cyclin D1 and cyclin B1, as well as cyclin-dependent kinase 2 (CDK2). These nontumor cells respond to Cu-induced changes in the oxidative balance by increase of the levels of reduced intracellular glutathione (GSH), decrease of reactive oxygen species (ROS) generation, and accumulation during progression of the cell cycle, thus preventing the cell abnormal proliferation or death. Taken together, our findings revealed an effect that contributes to prevent a possible damage of normal cells exposed to chemotherapeutic effects of drugs containing the Cu ion. PMID:26583055

Baicalein induces G1 arrest in oral cancer cells by enhancing the degradation of cyclin D1 and activating AhR to decrease Rb phosphorylation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Ya-Hsin, E-mail: yhcheng@mail.cmu.edu.tw; Li, Lih-Ann; Lin, Pinpin

Baicalein is a flavonoid, known to have anti-inflammatory and anti-cancer effects. As an aryl hydrocarbon receptor (AhR) ligand, baicalein at high concentrations blocks AhR-mediated dioxin toxicity. Because AhR had been reported to play a role in regulating the cell cycle, we suspected that the anti-cancer effect of baicalein is associated with AhR. This study investigated the molecular mechanism involved in the anti-cancer effect of baicalein in oral cancer cells HSC-3, including whether such effect would be AhR-mediated. Results revealed that baicalein inhibited cell proliferation and increased AhR activity in a dose-dependent manner. Cell cycle was arrested at the G1 phasemore » and the expression of CDK4, cyclin D1, and phosphorylated retinoblastoma (pRb) was decreased. When the AhR was suppressed by siRNA, the reduction of pRb was partially reversed, accompanied by a decrease of cell population at G1 phase and an increase at S phase, while the reduction of cyclin D1 and CDK4 did not change. This finding suggests that the baicalein activation of AhR is indeed associated with the reduction of pRb, but is independent of the reduction of cyclin D1 and CDK4. When cells were pre-treated with LiCl, the inhibitor of GSK-3β, the decrease of cyclin D1 was blocked and the reduction of pRb was recovered. The data indicates that in HSC-3 the reduction of pRb is both mediated by baicalein through activation of AhR and facilitation of cyclin D1 degradation, which causes cell cycle arrest at the G1 phase, and results in the inhibition of cell proliferation. -- Highlights: ► Baicalein causes the G1 phase arrest by decreasing Rb phosphorylation. ► Baicalein modulates AhR-mediated cell proliferation. ► Both AhR activation and cyclin D1 degradation results in hypophosphorylation of Rb. ► Baicalein facilitates cyclin D1 degradation by signalling the GSK-3β pathway.« less

Antitumor and antimetastatic actions of dihydroxycoumarins (esculetin or fraxetin) through the inhibition of M2 macrophage differentiation in tumor-associated macrophages and/or G1 arrest in tumor cells.

PubMed

Kimura, Yoshiyuki; Sumiyoshi, Maho

2015-01-05

Tumor growth and metastasis are closely associated with the M2 macrophage activation of tumor-associated macrophages (TAMs) in the tumor microenvironment as well as the development of tumor cells. In this study, we examined the antiproliferative, antitumor, and antimetastatic effects of three dihydroxycoumarins (esculetin, fraxetin, and daphnetin) against osteosarcoma LM8 cells (in vitro) and a highly metastatic model in LM8-bearing mice (in vivo). Esculetin (20-100μM) inhibited the proliferation of LM8 cells, whereas fraxetin and daphnetin had no effect. Esculetin inhibited the expressions of cyclin D1, cyclin-dependent kinase (CDK) 4 and matrix metalloproteinase (MMP)-2, and production of both transforming growth factor (TGF)-β1 and vascular endothelial growth factor (VEGF) in LM8 cells. Esculetin (3 or 10mg/kg) and fraxetin (10mg/kg) inhibited tumor growth and metastasis to the lung or liver, whereas daphnetin did not. These results suggested that the antitumor and antimetastatic actions of esculetin may be partly attributed to G1 arrest by the inhibition of cyclin D1 and CDK4 expression, while its antiangiogenic action may have been due to the inhibition of MMP-2 expression and TGF-β1 and VEGF productions at tumor sites. Esculetin (10-100μM) and fraxetin (50-100μM) inhibited the production of interleukin (IL)-10, monocyte chemoattractant protein (MCP)-1, and TGF-β1 during the differentiation of M2 macrophages by reducing the phosphorylation of Stat 3 without affecting its expression. These results also suggested that the antitumor and antimetastatic actions of esculetin or fraxetin may be due to the regulated activation of TAM by M2 macrophage differentiation in the tumor microenvironment. Copyright © 2014 Elsevier B.V. All rights reserved.

TRIM29 Overexpression Promotes Proliferation and Survival of Bladder Cancer Cells through NF-κB Signaling.

PubMed

Tan, Shu-Tao; Liu, Sheng-Ye; Wu, Bin

2016-10-01

TRIM29 overexpression has been reported in several human malignancies and showed correlation with cancer cell malignancy. The aim of the current study is to examine its clinical significance and biological roles in human bladder cancer tissues and cell lines. A total of 102 cases of bladder cancer tissues were examined for TRIM29 expression by immunohistochemistry. siRNA and plasmid transfection were performed in 5637 and BIU-87 cell lines. Cell Counting Kit-8, flow cytometry, western blot, and real-time polymerase chain reaction were performed to examine its biological roles and mechanism in bladder cancer cells. We found that TRIM29 overexpression showed correlation with invading depth (p=0.0087). Knockdown of TRIM29 expression in bladder cancer cell line 5637 inhibited cell growth rate and cell cycle transition while its overexpression in BIU-87 cells accelerated cell proliferation and cell cycle progression. TRIM29 overexpression also inhibited cell apoptosis induced by cisplatin. In addition, we demonstrated that TRIM29 depletion decreased while its overexpression led to upregulated expression of cyclin D1, cyclin E, and Bcl-2. We also showed that TRIM29 knockdown inhibited protein kinase C (PKC) and nuclear factor κB (NF-κB) signaling while its overexpression stimulated the PKC and NF-κB pathways. BAY 11-7082 (NF-κB inhibitor) partly attenuated the effect of TRIM29 on expression of cyclin and Bcl-2. Treatment with PKC inhibitor staurosporine resulted in ameliorated TRIM29 induced activation of NF-κB. The current study demonstrated that TRIM29 upregulates cyclin and Bcl family proteins level to facilitate malignant cell growth and inhibit drug-induced apoptosis in bladder cancer, possibly through PKC-NF-κB signaling pathways.

Human cytomegalovirus tegument protein pp150 acts as a cyclin A2-CDK-dependent sensor of the host cell cycle and differentiation state.

PubMed

Bogdanow, Boris; Weisbach, Henry; von Einem, Jens; Straschewski, Sarah; Voigt, Sebastian; Winkler, Michael; Hagemeier, Christian; Wiebusch, Lüder

2013-10-22

Upon cell entry, herpesviruses deliver a multitude of premade virion proteins to their hosts. The interplay between these incoming proteins and cell-specific regulatory factors dictates the outcome of infections at the cellular level. Here, we report a unique type of virion-host cell interaction that is essential for the cell cycle and differentiation state-dependent onset of human cytomegalovirus (HCMV) lytic gene expression. The major tegument 150-kDa phosphoprotein (pp150) of HCMV binds to cyclin A2 via a functional RXL/Cy motif resulting in its cyclin A2-dependent phosphorylation. Alanine substitution of the RXL/Cy motif prevents this interaction and allows the virus to fully escape the cyclin-dependent kinase (CDK)-mediated block of immediate early (IE) gene expression in S/G2 phase that normally restricts the onset of the HCMV replication cycle to G0/G1. Furthermore, the cyclin A2-CDK-pp150 axis is also involved in the establishment of HCMV quiescence in NTera2 cells, showing the importance of this molecular switch for differentiation state-dependent regulation of IE gene expression. Consistent with the known nucleocapsid-binding function of pp150, its RXL/Cy-dependent phosphorylation affects gene expression of the parental virion only, suggesting a cis-acting, virus particle-associated mechanism of control. The pp150 homologs of other primate and mammalian CMVs lack an RXL/Cy motif and accordingly even the nearest relative of HCMV, chimpanzee CMV, starts its lytic cycle in a cell cycle-independent manner. Thus, HCMV has evolved a molecular sensor for cyclin A2-CDK activity to restrict its IE gene expression program as a unique level of self-limitation and adaptation to its human host.

CUDR promotes liver cancer stem cell growth through upregulating TERT and C-Myc

PubMed Central

Pu, Hu; Zheng, Qidi; Li, Haiyan; Wu, Mengying; An, Jiahui; Gui, Xin; Li, Tianming; Lu, Dongdong

2015-01-01

Cancer up-regulated drug resistant (CUDR) is a novel non-coding RNA gene. Herein, we demonstrate excessive CUDR cooperates with excessive CyclinD1 or PTEN depletion to accelerate liver cancer stem cells growth and liver stem cell malignant transformation in vitro and in vivo. Mechanistically, we reveal the decrease of PTEN in cells may lead to increase binding capacity of CUDR to CyclinD1. Therefore, CUDR-CyclinD1 complex loads onto the long noncoding RNA H19 promoter region that may lead to reduce the DNA methylation on H19 promoter region and then to enhance the H19 expression. Strikingly, the overexpression of H19 increases the binding of TERT to TERC and reduces the interplay between TERT with TERRA, thus enhancing the cell telomerase activity and extending the telomere length. On the other hand, insulator CTCF recruits the CUDR-CyclinD1 complx to form the composite CUDR-CyclinD1-insulator CTCF complex which occupancied on the C-myc gene promoter region, increasing the outcome of oncogene C-myc. Ultimately, excessive TERT and C-myc lead to liver cancer stem cell and hepatocyte-like stem cell malignant proliferation. To understand the novel functions of long noncoding RNA CUDR will help in the development of new liver cancer therapeutic and diagnostic approaches. PMID:26513297

Circular RNA 0000096 affects cell growth and migration in gastric cancer.

PubMed

Li, Peifei; Chen, Huilin; Chen, Shengcan; Mo, Xiaoyan; Li, Tianwen; Xiao, Bingxiu; Yu, Rui; Guo, Junming

2017-02-28

Circular RNAs (circRNAs) are a class of non-coding RNAs broadly expressed in cells of various species. Their role in cancers, especially in gastric cancer, is poorly understood. Circular RNA 0000096 (hsa_circ_0000096) levels in 101 paired gastric cancer tissues and adjacent non-tumorous tissues from patients with gastric cancer were detected by real-time quantitative reverse transcription-polymerase chain reaction. A receiver operating characteristic curve was generated to evaluate the diagnostic value of hsa_circ_0000096. RNA interference was used to manipulate the expression of hsa_circ_0000096. Its biological effects were evaluated by flow cytometry, real-time cell analysis, a wound scratch assay, western blot analysis and xenograft models. Hsa_circ_0000096 was found to be significantly downregulated in gastric cancer tissues and gastric cancer cell lines compared with paired adjacent non-tumorous tissues and normal gastric epithelial cells (P<0.001). Moreover, knockdown of hsa_circ_0000096 significantly inhibited cell proliferation and migration in vitro and in vivo. The results of both immunohistochemical and western blot analyses showed that the protein levels of cyclin D1, cyclin-dependent kinase 6 (CDK6), matrix metalloproteinase-2 and MMP-9 were significantly reduced in vitro and in vivo. A gastric cancer xenograft nude mouse model indicated that Ki67 and VEGF were reduced in a dose-dependent manner following knockdown of hsa_circ_0000096. However, the expression of E-cadherin increased. Hsa_circ_0000096 may be used as a potential novel biomarker for gastric cancer. It affects gastric cancer cell growth and migration by regulating cyclin D1, CDK6, MMP-2 and MMP-9.

Fisetin inhibits the growth and migration in the A549 human lung cancer cell line via the ERK1/2 pathway.

PubMed

Wang, Junjian; Huang, Shaoxiang

2018-03-01

Lung cancer is the most prevalent malignant tumor type in the developed world and the discovery of novel anti-tumor drugs is a research hotspot. Fisetin, a naturally occurring flavonoid, has been reported to have anti-cancer effects in multiple tumor types. The present study found that fisetin inhibited the growth and migration of non-small cell lung cancer in vitro . MTT, wound-healing, cell-matrix adhesion and Transwell assays were performed and demonstrated that fisetin suppressed proliferation, migration, adhesion and invasion, respectively. Flow cytometric analysis indicated that fisetin induced apoptosis in the A549 cell line by decreasing the expression of c-myc, cyclin-D1, cyclooxygenase-2, B cell lymphoma-2, CXC chemokine receptor type 4, cluster of differentiation 44 and metalloproteinase-2/9, increasing the expression of cyclin dependent kinase inhibitor (CDKN) 1A/B, CDKN2D and E-cadherin and increasing the activity of caspase-3/9 via targeting the extracellular signal-regulated kinase signaling pathway. The results provided comprehensive evidence for the anti-tumor effects of fisetin in non-small cell lung cancer in vitro , which may provide a novel approach for clinical treatment.

Fisetin inhibits the growth and migration in the A549 human lung cancer cell line via the ERK1/2 pathway

PubMed Central

Wang, Junjian; Huang, Shaoxiang

2018-01-01

Lung cancer is the most prevalent malignant tumor type in the developed world and the discovery of novel anti-tumor drugs is a research hotspot. Fisetin, a naturally occurring flavonoid, has been reported to have anti-cancer effects in multiple tumor types. The present study found that fisetin inhibited the growth and migration of non-small cell lung cancer in vitro. MTT, wound-healing, cell-matrix adhesion and Transwell assays were performed and demonstrated that fisetin suppressed proliferation, migration, adhesion and invasion, respectively. Flow cytometric analysis indicated that fisetin induced apoptosis in the A549 cell line by decreasing the expression of c-myc, cyclin-D1, cyclooxygenase-2, B cell lymphoma-2, CXC chemokine receptor type 4, cluster of differentiation 44 and metalloproteinase-2/9, increasing the expression of cyclin dependent kinase inhibitor (CDKN) 1A/B, CDKN2D and E-cadherin and increasing the activity of caspase-3/9 via targeting the extracellular signal-regulated kinase signaling pathway. The results provided comprehensive evidence for the anti-tumor effects of fisetin in non-small cell lung cancer in vitro, which may provide a novel approach for clinical treatment. PMID:29467859

Inhibition of Smooth Muscle Proliferation by Urea-Based Alkanoic Acids via Peroxisome Proliferator-Activated Receptor α–Dependent Repression of Cyclin D1

PubMed Central

Ng, Valerie Y.; Morisseau, Christophe; Falck, John R.; Hammock, Bruce D.; Kroetz, Deanna L.

2007-01-01

Objective Proliferation of smooth muscle cells is implicated in cardiovascular complications. Previously, a urea-based soluble epoxide hydrolase inhibitor was shown to attenuate smooth muscle cell proliferation. We examined the possibility that urea-based alkanoic acids activate the nuclear receptor peroxisome proliferator-activated receptor α (PPARα) and the role of PPARα in smooth muscle cell proliferation. Methods and Results Alkanoic acids transactivated PPARα, induced binding of PPARα to its response element, and significantly induced the expression of PPARα-responsive genes, showing their function as PPARα agonists. Furthermore, the alkanoic acids attenuated platelet-derived growth factor–induced smooth muscle cell proliferation via repression of cyclin D1 expression. Using small interfering RNA to decrease endogenous PPARα expression, it was determined that PPARα was partially involved in the cyclin D1 repression. The antiproliferative effects of alkanoic acids may also be attributed to their inhibitory effects on soluble epoxide hydrolase, because epoxyeicosatrienoic acids alone inhibited smooth muscle cell proliferation. Conclusions These results show that attenuation of smooth muscle cell proliferation by urea-based alkanoic acids is mediated, in part, by the activation of PPARα. These acids may be useful for designing therapeutics to treat diseases characterized by excessive smooth muscle cell proliferation. PMID:16917105

Rapamycin Enhances Repressed Autophagy and Attenuates Aggressive Progression in a Rat Model of IgA Nephropathy.

PubMed

Liu, Di; Liu, Yexin; Chen, Guochun; He, Liyu; Tang, Chengyuan; Wang, Chang; Yang, Danyi; Li, Huiqiong; Dong, Zheng; Liu, Hong

2017-01-01

IgA nephropathy (IgAN) has been considered to be the most frequent form of primary glomerulonephritis that occurs worldwide with a variety of factors involved in its occurrence and development. The impact of autophagy in IgAN, however, remains partially unclear. This study was designed to investigate the effects of rapamycin in an IgAN model. After establishing an IgAN rat model, SD rats were divided into 4 groups: control, control + rapamycin, IgAN, IgAN + rapamycin. Proteinuria and the pathological changes and the level of autophagy of kidney were texted. Identify the expression of phosphorylation and total mammalian target of rapamycin (mTOR) and s6k1 as well as cyclin D1 in the kidney of rats through Western blot and immunohistochemistry. With rapamycin treatment, we observed a significant reduction in the progression of proteinuria as well as alleviation of pathological lesions in IgAN rats. Besides, autophagy was inhibited, while the mTOR/S6k1 pathway was activated and expression of cyclin D1 was increased in IgAN. Rapamycin treatment increased autophagy and decreased the expression of cyclin D1. These results may suggest that mTOR-mediated autophagy inhibition may result in mesangial cell proliferation in IgAN. © 2017 S. Karger AG, Basel.

Parathyroid cell growth in patients with advanced secondary hyperparathyroidism: vitamin D receptor and cyclin-dependent kinase inhibitors, p21 and p27.

PubMed

Tokumoto, Masanori; Tsuruya, Kazuhiko; Fukuda, Kyoichi; Kanai, Hidetoshi; Kuroki, Shoji; Hirakata, Hideki; Iida, Mitsuo

2003-06-01

Uraemic patients with advanced secondary hyperparathyroidism (2HPT) have nodular hyperplastic glands with a decreased vitamin D receptor (VDR) density. Previous studies have shown that nodular hyperplasia expressed a significantly lower VDR density as compared with diffuse hyperplasia, and the VDR density negatively correlated with both the glandular weight and the marker of cell proliferation. However, the mechanism by which the decreased VDR density leads to parathyroid cell proliferation remains unclear. In the myelomonocytic cell line, active vitamin D(3) is known to activate the transcription of both p21 and p27, cyclin-dependent kinase inhibitors (CDKIs), regulating the transition from the G(1) to the S phase of the cell cycle, in a VDR-dependent manner. Moreover, the overexpression of p21 and p27 inhibits cell proliferation. In order to elucidate the mechanism of parathyroid cell proliferation, the expression of CDKIs, p21 and p27, and the VDR was analysed immunohistochemically, and compared among nodular and diffuse hyperplastic parathyroid glands, and histologically normal parathyroid glands. The VDR expression in nodular hyperplasias was significantly decreased compared with either diffuse hyperplasias or normal parathyroid glands. The expression of both p21 and p27 was also significantly lower in nodular hyperplasias than in diffuse hyperplasias or normal parathyroid glands. Sections of parathyroid glands with a high expression of nuclear VDR highly expressed both p21 and p27. In nodular hyperplasias, the expression of both p21 and p27 correlated either positively with the nuclear VDR expression or inversely with the glandular weight. Therefore, the reduced expression of p21 and p27, being VDR dependent, is a major pathogenic factor for nodular parathyroid gland growth in advanced 2HPT.

A Clb/Cdk1-mediated regulation of Fkh2 synchronizes CLB expression in the budding yeast cell cycle.

PubMed

Linke, Christian; Chasapi, Anastasia; González-Novo, Alberto; Al Sawad, Istabrak; Tognetti, Silvia; Klipp, Edda; Loog, Mart; Krobitsch, Sylvia; Posas, Francesc; Xenarios, Ioannis; Barberis, Matteo

2017-01-01

Precise timing of cell division is achieved by coupling waves of cyclin-dependent kinase (Cdk) activity with a transcriptional oscillator throughout cell cycle progression. Although details of transcription of cyclin genes are known, it is unclear which is the transcriptional cascade that modulates their expression in a timely fashion. Here, we demonstrate that a Clb/Cdk1-mediated regulation of the Fkh2 transcription factor synchronizes the temporal mitotic CLB expression in budding yeast. A simplified kinetic model of the cyclin/Cdk network predicts a linear cascade where a Clb/Cdk1-mediated regulation of an activator molecule drives CLB3 and CLB2 expression. Experimental validation highlights Fkh2 as modulator of CLB3 transcript levels, besides its role in regulating CLB2 expression. A Boolean model based on the minimal number of interactions needed to capture the information flow of the Clb/Cdk1 network supports the role of an activator molecule in the sequential activation, and oscillatory behavior, of mitotic Clb cyclins. This work illustrates how transcription and phosphorylation networks can be coupled by a Clb/Cdk1-mediated regulation that synchronizes them.

Spinal Cord Injury Causes Brain Inflammation Associated with Cognitive and Affective Changes: Role of Cell Cycle Pathways

PubMed Central

Zhao, Zaorui; Sabirzhanov, Boris; Stoica, Bogdan A.; Kumar, Alok; Luo, Tao; Skovira, Jacob; Faden, Alan I.

2014-01-01

Experimental spinal cord injury (SCI) causes chronic neuropathic pain associated with inflammatory changes in thalamic pain regulatory sites. Our recent studies examining chronic pain mechanisms after rodent SCI showed chronic inflammatory changes not only in thalamus, but also in other regions including hippocampus and cerebral cortex. Because changes appeared similar to those in our rodent TBI models that are associated with neurodegeneration and neurobehavioral dysfunction, we examined effects of mouse SCI on cognition, depressive-like behavior, and brain inflammation. SCI caused spatial and retention memory impairment and depressive-like behavior, as evidenced by poor performance in the Morris water maze, Y-maze, novel objective recognition, step-down passive avoidance, tail suspension, and sucrose preference tests. SCI caused chronic microglial activation in the hippocampus and cerebral cortex, where microglia with hypertrophic morphologies and M1 phenotype predominated. Stereological analyses showed significant neuronal loss in the hippocampus at 12 weeks but not 8 d after injury. Increased cell-cycle-related gene (cyclins A1, A2, D1, E2F1, and PCNA) and protein (cyclin D1 and CDK4) expression were found chronically in hippocampus and cerebral cortex. Systemic administration of the selective cyclin-dependent kinase inhibitor CR8 after SCI significantly reduced cell cycle gene and protein expression, microglial activation and neurodegeneration in the brain, cognitive decline, and depression. These studies indicate that SCI can initiate a chronic brain neurodegenerative response, likely related to delayed, sustained induction of M1-type microglia and related cell cycle activation, which result in cognitive deficits and physiological depression. PMID:25122899

Targeting of the MUC1-C Oncoprotein in Colitis-Associated Colorectal Cancer

DTIC Science & Technology

2014-11-01

separated by infiltrates of inflammatory cells and the presence of crypt abscess (lower left panel). With progression to dysplasia, the crypts are...Rajabi, H, et al., MUC1-C oncoprotein induces TCF7L2 activation and promotes cyclin D1 expression in human breast cancer cells. J Biol Chem, 2012

G protein-coupled receptor 30 (GPR30) mediates gene expression changes and growth response to 17beta-estradiol and selective GPR30 ligand G-1 in ovarian cancer cells.

PubMed

Albanito, Lidia; Madeo, Antonio; Lappano, Rosamaria; Vivacqua, Adele; Rago, Vittoria; Carpino, Amalia; Oprea, Tudor I; Prossnitz, Eric R; Musti, Anna Maria; Andò, Sebastiano; Maggiolini, Marcello

2007-02-15

Estrogens play a crucial role in the development of ovarian tumors; however, the signal transduction pathways involved in hormone action are still poorly defined. The orphan G protein-coupled receptor 30 (GPR30) mediates the nongenomic signaling of 17beta-estradiol (E2) in a variety of estrogen-sensitive cancer cells through activation of the epidermal growth factor receptor (EGFR) pathway. Whether estrogen receptor alpha (ERalpha) also contributes to GPR30/EGFR signaling is less understood. Here, we show that, in ERalpha-positive BG-1 ovarian cancer cells, both E2 and the GPR30-selective ligand G-1 induced c-fos expression and estrogen-responsive element (ERE)-independent activity of a c-fos reporter gene, whereas only E2 stimulated an ERE-responsive reporter gene, indicating that GPR30 signaling does not activate ERalpha-mediated transcription. Similarly, both ligands up-regulated cyclin D1, cyclin E, and cyclin A, whereas only E2 enhanced progesterone receptor expression. Moreover, both GPR30 and ERalpha expression are required for c-fos stimulation and extracellular signal-regulated kinase (ERK) activation in response to either E2 or G-1. Inhibition of the EGFR transduction pathway inhibited c-fos stimulation and ERK activation by either ligand, suggesting that in ovarian cancer cells GPR30/EGFR signaling relays on ERalpha expression. Interestingly, we show that both GPR30 and ERalpha expression along with active EGFR signaling are required for E2-stimulated and G-1-stimulated proliferation of ovarian cancer cells. Because G-1 was able to induce both c-fos expression and proliferation in the ERalpha-negative/GPR30-positive SKBR3 breast cancer cells, the requirement for ERalpha expression in GPR30/EGFR signaling may depend on the specific cellular context of different tumor types.

Phloretin induces cell cycle arrest and apoptosis of human glioblastoma cells through the generation of reactive oxygen species.

PubMed

Liu, Yuanyuan; Fan, Chenghe; Pu, Lv; Wei, Cui; Jin, Haiqiang; Teng, Yuming; Zhao, Mingming; Yu, Albert Cheung Hoi; Jiang, Feng; Shu, Junlong; Li, Fan; Peng, Qing; Kong, Jian; Pan, Bing; Zheng, Lemin; Huang, Yining

2016-06-01

Phloretin, a flavonoid present in various plants, has been reported to exert anticarcinogenic effects. However, the mechanism of its chemo-preventive effect on human glioblastoma cells is not fully understood. This study aimed to investigate the molecular mechanism of phloretin and its associated chemo-preventive effect in human glioblastoma cells. The results indicate that phloretin inhibited cell proliferation by inducing cell cycle arrest at the G0-G1 phase and induced apoptosis of human glioblastoma cells. Phloretin-induced cell cycle arrest was associated with increased expression of p27 and decreased expression of cdk2, cdk4, cdk6, cyclinD and cyclinE. Moreover, the PI3K/AKT/mTOR signaling cascades were suppressed by phloretin in a dose-dependent manner. In addition, phloretin triggered the mitochondrial apoptosis pathway and generated reactive oxygen species (ROS). This was accompanied by the up-regulation of Bax, Bak and c-PARP and the down-regulation of Bcl-2. The antioxidant agents N-acetyl-L-cysteine and glutathione weakened the effect of phloretin on glioblastoma cells. In conclusion, these results demonstrate that phloretin exerts potent chemo-preventive activity in human glioblastoma cells through the generation of ROS.

Nuclear accumulation of cyclin D1 following long-term fractionated exposures to low-dose ionizing radiation in normal human diploid cells.

PubMed

Shimura, Tsutomu; Hamada, Nobuyuki; Sasatani, Megumi; Kamiya, Kenji; Kunugita, Naoki

2014-01-01

Cyclin D1 is a mitogenic sensor that responds to growth signals from the extracellular environment and regulates the G 1-to-S cell cycle transition. When cells are acutely irradiated with a single dose of 10 Gy, cyclin D1 is degraded, causing cell cycle arrest at the G 1/S checkpoint. In contrast, cyclin D1 accumulates in human tumor cells that are exposed to long-term fractionated radiation (0.5 Gy/fraction of X-rays). In this study we investigated the effect of fractionated low-dose radiation exposure on cyclin D1 localization in 3 strains of normal human fibroblasts. To specifically examine the nuclear accumulation of cyclin D1, cells were treated with a hypotonic buffer containing detergent to remove cytoplasmic cyclin D1. Proliferating cell nuclear antigen (PCNA) immunofluorescence was used to identify cells in S phase. With this approach, we observed S-phase nuclear retention of cyclin D1 following low-dose fractionated exposures, and found that cyclin D1 nuclear retention increased with exposure time. Cells that retained nuclear cyclin D1 were more likely to have micronuclei than non-retaining cells, indicating that the accumulation of nuclear cyclin D1 was associated with genomic instability. Moreover, inhibition of the v-akt murine thymoma viral oncogene homolog (AKT) pathway facilitated cyclin D1 degradation and eliminated cyclin D1 nuclear retention in cells exposed to fractionated radiation. Thus, cyclin D1 may represent a useful marker for monitoring long-term effects associated with exposure to low levels of radiation.

Nuclear accumulation of cyclin D1 following long-term fractionated exposures to low-dose ionizing radiation in normal human diploid cells

PubMed Central

Shimura, Tsutomu; Hamada, Nobuyuki; Sasatani, Megumi; Kamiya, Kenji; Kunugita, Naoki

2014-01-01

Cyclin D1 is a mitogenic sensor that responds to growth signals from the extracellular environment and regulates the G1-to-S cell cycle transition. When cells are acutely irradiated with a single dose of 10 Gy, cyclin D1 is degraded, causing cell cycle arrest at the G1/S checkpoint. In contrast, cyclin D1 accumulates in human tumor cells that are exposed to long-term fractionated radiation (0.5 Gy/fraction of X-rays). In this study we investigated the effect of fractionated low-dose radiation exposure on cyclin D1 localization in 3 strains of normal human fibroblasts. To specifically examine the nuclear accumulation of cyclin D1, cells were treated with a hypotonic buffer containing detergent to remove cytoplasmic cyclin D1. Proliferating cell nuclear antigen (PCNA) immunofluorescence was used to identify cells in S phase. With this approach, we observed S-phase nuclear retention of cyclin D1 following low-dose fractionated exposures, and found that cyclin D1 nuclear retention increased with exposure time. Cells that retained nuclear cyclin D1 were more likely to have micronuclei than non-retaining cells, indicating that the accumulation of nuclear cyclin D1 was associated with genomic instability. Moreover, inhibition of the v-akt murine thymoma viral oncogene homolog (AKT) pathway facilitated cyclin D1 degradation and eliminated cyclin D1 nuclear retention in cells exposed to fractionated radiation. Thus, cyclin D1 may represent a useful marker for monitoring long-term effects associated with exposure to low levels of radiation. PMID:24583467

Cell Cycle Regulators during Human Atrial Development

PubMed Central

Kim, Won Ho; Joo, Chan Uhng; Ku, Ja Hong; Ryu, Chul Hee; Koh, Keum Nim; Koh, Gou Young; Ko, Jae Ki

1998-01-01

Objectives The molecular mechanisms that regulate cardiomyocyte cell cycle and terminal differentiation in humans remain largely unknown. To determine which cyclins, cyclin dependent kinases (CDKs) and cyclin kinase inhibitors (CKIs) are important for cardiomyocyte proliferation, we have examined protein levels of cyclins, CDKs and CKIs during normal atrial development in humans. Methods Atrial tissues were obtained in the fetus from inevitable abortion and in the adult during surgery, Cyclin and CDK proteins were determined by Western blot analysis, CDK activities were determined by phosphorylation amount using specific substrate. Results Most cyclins and CDKs were high during the fetal period and their levels decreased at different rates during the adult period. While the protein levels of cyclin D1, cyclin D3, CDK4, CDK6 and CDK2 were still detectable in adult atria, the protein levels of cyclin E, cyclin A, cyclin B, cdc2 and PCNA were not detectable. Interestingly, p27KIP 1 protein increased markedly in the adult period, while p21C IP 1 protein in atria was detectable only in the fetal period. While the activities of CDK6, CDK2 and cdc2 decreased markedly, the activity of CDK4 did not change from the fetal period to the adult period. Conclusion These findings indicate that marked reduction of protein levels and activities of cyclins and CDKs, and marked induction of p27KIP 1 in atria, are associated with the withdrawal of cardiac cell cycle in adult humans. PMID:9735660

FGF2 and insulin signaling converge to regulate cyclin D expression in multipotent neural stem cells.

PubMed

Adepoju, Adedamola; Micali, Nicola; Ogawa, Kazuya; Hoeppner, Daniel J; McKay, Ronald D G

2014-03-01

The ex vivo expansion of stem cells is making major contribution to biomedical research. The multipotent nature of neural precursors acutely isolated from the developing central nervous system has been established in a series of studies. Understanding the mechanisms regulating cell expansion in tissue culture would support their expanded use either in cell therapies or to define disease mechanisms. Basic fibroblast growth factor (FGF2) and insulin, ligands for tyrosine kinase receptors, are sufficient to sustain neural stem cells (NSCs) in culture. Interestingly, real-time imaging shows that these cells become multipotent every time they are passaged. Here, we analyze the role of FGF2 and insulin in the brief period when multipotent cells are present. FGF2 signaling results in the phosphorylation of Erk1/2, and activation of c-Fos and c-Jun that lead to elevated cyclin D mRNA levels. Insulin signals through the PI3k/Akt pathway to regulate cyclins at the post-transcriptional level. This precise Boolean regulation extends our understanding of the proliferation of multipotent NSCs and provides a basis for further analysis of proliferation control in the cell states defined by real-time mapping of the cell lineages that form the central nervous system. © 2013 AlphaMed Press.

Wogonin inhibits the proliferation and invasion, and induces the apoptosis of HepG2 and Bel7402 HCC cells through NF‑κB/Bcl-2, EGFR and EGFR downstream ERK/AKT signaling.

PubMed

Liu, Xiaodong; Tian, Shuo; Liu, Mei; Jian, Lingyan; Zhao, Limei

2016-10-01

The anticancer effects of the natural flavonoid, wogonin, have been reported. However, its molecular mechanisms of action have not yet been fully explored. In the present study, we aimed to examine the molecular mechanisms of action of wogonin and its effects on the biological behavior of the HepG2 and Bel7402 hepatocellular carcinoma (HCC) cell lines. We also examined the effects of wogonin on nuclear factor-κB (NF-κB)/Bcl-2 and epidermal growth factor receptor (EGFR) signaling, as well as on downstream pathways of EGFR, namely extracellular signal-regulated kinase (ERK)/AKT signaling. We found that treatment with wogonin inhibited the proliferation and invasion, and induced the apoptosis of the HepG2 and Bel7402 cells. In addition, treatment with wogonin decreased cyclin D1, cyclin E, CDK4/6, Bcl-2 and matrix metalloproteinase 2 (MMP2) expression, and promoted the cleavage of caspase-3 and caspase-9 in a concentration-dependent manner. Further experiments revealed that wogonin inhibited NF-κB/Bcl-2 signaling by decreasing the IκB and p65 phosphorylation levels. Wogonin also inhibited the activation of the EGFR (Tyr845) signaling pathway, and that of downstream pathways of EGFR, namely ERK/AKT/MMP2 signaling. The depletion of EGFR by siRNA partly abolished the inhibitory effects of wogonin on cyclin D1, MMP2 expression. On the whole, our our findings demonstrate that wogonin effectively suppresses the proliferation, invasion and survival of HCC cells through the modulation of the NF-κB and EGFR signaling pathways.

Differential regulation of the cell cycle by alpha1-adrenergic receptor subtypes.

PubMed

Gonzalez-Cabrera, Pedro J; Shi, Ting; Yun, June; McCune, Dan F; Rorabaugh, Boyd R; Perez, Dianne M

2004-11-01

Alpha(1)-Adrenergic receptors have been implicated in growth-promoting pathways. A microarray study of individual alpha(1)-adrenergic receptor subtypes (alpha(1A), alpha(1B), and alpha(1D)) expressed in Rat-1 fibroblasts revealed that epinephrine altered the transcription of several cell cycle regulatory genes in a direction consistent with the alpha(1A)- and alpha(1D)-adrenergic receptors mediating G(1)-S cell cycle arrest and the alpha(1B-)mediating cell-cycle progression. A time course indicated that in alpha(1A) cells, epinephrine stimulated a G(1)-S arrest, which began after 8 h of stimulation and maximized at 16 h, at which point was completely blocked with cycloheximide. The alpha(1B)-adrenergic receptor profile also showed unchecked cell cycle progression, even under low serum conditions and induced foci formation. The G(1)-S arrest induced by alpha(1A)- and alpha(1D)-adrenergic receptors was associated with decreased cyclin-dependent kinase-6 and cyclin E-associated kinase activities and increased expression of the cyclin-dependent kinase inhibitor p27(Kip1), all of which were blocked by prazosin. There were no differences in kinase activities and/or expression of p27(Kip1) in epinephrine alpha(1B)-AR fibroblasts, although the microarray did indicate differences in p27(Kip1) RNA levels. Cell counts proved the antimitotic effect of epinephrine in alpha(1A) and alpha(1D) cells and indicated that alpha(1B)-adrenergic receptor subtype expression was sufficient to cause proliferation of Rat-1 fibroblasts independent of agonist stimulation. Analysis in transfected PC12 cells also confirmed the alpha(1A)- and alpha(1B)-adrenergic receptor effect. The alpha(1B)-subtype native to DDT1-MF2 cells, a smooth muscle cell line, caused progression of the cell cycle. These results indicate that the alpha(1A)- and alpha(1D)-adrenergic receptors mediate G(1)-S cell-cycle arrest, whereas alpha(1B)-adrenergic receptor expression causes a cell cycle progression and may induce transformation in sensitive cell lines.

Identification of an hexapeptide that binds to a surface pocket in cyclin A and inhibits the catalytic activity of the complex cyclin-dependent kinase 2-cyclin A.

PubMed

Canela, Núria; Orzáez, Mar; Fucho, Raquel; Mateo, Francesca; Gutierrez, Ricardo; Pineda-Lucena, Antonio; Bachs, Oriol; Pérez-Payá, Enrique

2006-11-24

The protein-protein complexes formed between different cyclins and cyclin-dependent kinases (CDKs) are central to cell cycle regulation. These complexes represent interesting points of chemical intervention for the development of antineoplastic molecules. Here we describe the identification of an all d-amino acid hexapeptide, termed NBI1, that inhibits the kinase activity of the cyclin-dependent kinase 2 (cdk2)-cyclin A complex through selective binding to cyclin A. The mechanism of inhibition is non-competitive for ATP and non-competitive for protein substrates. In contrast to the existing CDKs peptide inhibitors, the hexapeptide NBI1 interferes with the formation of the cdk2-cyclin A complex. Furthermore, a cell-permeable derivative of NBI1 induces apoptosis and inhibits proliferation of tumor cell lines. Thus, the NBI1-binding site on cyclin A may represent a new target site for the selective inhibition of activity cdk2-cyclin A complex.

Induction of miR-137 by isorhapontigenin (ISO) direct targeted Sp1 protein translation and mediated its anti-cancer activity both in vitro and in vivo

PubMed Central

Zeng, Xingruo; Xu, Zhou; Gu, Jiayan; Huang, Haishan; Gao, Guangxun; Zhang, Xiaoru; Li, Jingxia; Jin, Honglei; Jiang, Guosong; Sun, Hong; Huang, Chuanshu

2016-01-01

Our recent studies found that isorhapontigenin (ISO) showed a significant inhibitory effect on human bladder cancer cell growth, accompanied with cell cycle G0/G1 arrest as well as down-regulation of Cyclin D1 expression at transcriptional level via inhibition of Sp1 transactivation in bladder cancer cells. In current studies, the potential ISO inhibition of bladder tumor formation has been explored in xenograft nude mouse model, and the molecular mechanisms underlying ISO inhibition of Sp1 expression and anti-cancer activities has been elucidated both in vitro and in vivo. Moreover, the studies demonstrated that ISO treatment induced the expression of miR-137, which in turn suppressed Sp1 protein translation by direct targeting Sp1 mRNA 3′UTR. Similar to ISO treatment, ectopic expression of miR-137 alone led to G0/G1 cell growth arrest and inhibition of anchorage-independent growth in human bladder cancer cells, which could be completely reversed by over-expression of GFP-Sp1. The inhibition of miR-137 expression attenuated ISO-induced the inhibition of Sp1/Cyclin D1 expression, and induction of G0/G1 cell growth arrest and suppression of cell anchorage-independent growth. Taken together, our studies have demonstrated that miR-137 induction by ISO targets Sp1 mRNA 3′UTR and inhibits Sp1 protein translation, which consequently results in reduction of Cyclin D1 expression, induction of G0/G1 growth arrest and inhibition of anchorage-independent growth in vitro and in vivo. Our results have provided novel insights into understanding the anti-cancer activity of ISO in the therapy of human bladder cancer. PMID:26832795

α-Lipoic acid inhibits human lung cancer cell proliferation through Grb2-mediated EGFR downregulation.

PubMed

Yang, Lan; Wen, Ya; Lv, Guoqing; Lin, Yuntao; Tang, Junlong; Lu, Jingxiao; Zhang, Manqiao; Liu, Wen; Sun, Xiaojuan

2017-12-09

Alpha lipoic acid (α -LA) is a naturally occurring antioxidant and metabolic enzyme co-factor. Recently, α -LA has been reported to inhibit the growth of various cancer cells, but the precise signaling pathways that mediate the effects of α -LA on non-small cell lung cancer (NSCLC) development remain unclear. The CCK-8 assay was used to assess cell proliferation in NSCLC cell lines after α -LA treatment. The expression of growth factor receptor-bound protein 2 (Grb2), cyclin-dependent kinase (CDK)-2, CDK4, CDK6, Cyclin D3, Cyclin E1, Ras, c-Raf, epidermal growth factor receptor (EGFR), ERK1/2 and activated EGFR and ERK1/2 was evaluated by western blotting. Grb2 levels were restored in α-LA-treated cells by transfection of a plasmid carrying Grb2 and were reduced in NSCLC cells via specific siRNA-mediated knockdown. α -LA dramatically decreased NSCLC cell proliferation by downregulating Grb2; in contrast, Grb2 overexpression significantly prevented α-LA-induced decrease in cell growth in vitro. Western blot analysis indicated that α-LA decreased the levels of phospho-EGFR, CDK2/4/6, Cyclins D3 and E1, which are associated with the inhibition of G1/S-phase transition. Additional experiments indicated that Grb2 inhibition partially abolished EGF-induced phospho-EGFR and phospho-ERK1/2 activity. In addition, α-LA exerted greater inhibitory effects than gefitinib on NSCLC cells by preventing EGF-induced EGFR activation. For the first time, these findings provide the first evidence that α-LA inhibits cell proliferation through Grb2 by suppressing EGFR phosphorylation and that MAPK/ERK is involved in this pathway. Copyright © 2017. Published by Elsevier Inc.

Modulated Expression of Genes Encoding Estrogen Metabolizing Enzymes by G1-Phase Cyclin-Dependent Kinases 6 and 4 in Human Breast Cancer Cells

PubMed Central

Jia, Yi; Domenico, Joanne; Swasey, Christina; Wang, Meiqin; Gelfand, Erwin W.; Lucas, Joseph J.

2014-01-01

G1-phase cell cycle defects, such as alterations in cyclin D1 or cyclin-dependent kinase (cdk) levels, are seen in most tumors. For example, increased cyclin D1 and decreased cdk6 levels are seen in many human breast tumors. Overexpression of cdk6 in breast tumor cells in culture has been shown to suppress proliferation, unlike the growth stimulating effects of its close homolog, cdk4. In addition to directly affecting proliferation, alterations in cdk6 or cdk4 levels in breast tumor cells also differentially influence levels of numerous steroid metabolic enzymes (SMEs), including those involved in estrogen metabolism. Overexpression of cdk6 in tumor cell lines having low cdk6 resulted in decreased levels of mRNAs encoding aldo-keto reductase (AKR)1C1, AKR1C2 and AKR1C3, which are hydroxysteroid dehydrogenases (HSDs) involved in steroid hormone metabolism. In contrast, increasing cdk4 dramatically increased these transcript levels, especially those encoding AKR1C3, an enzyme that converts estrone to 17β-estradiol, a change that could result in a pro-estrogenic state favoring tumor growth. Effects on other estrogen metabolizing enzymes, including cytochrome P450 (CYP) 19 aromatase, 17β-HSD2, and CYP1B1 transcripts, were also observed. Interactions of cdk6 and cdk4, but not cyclin D1, with the promoter region of a cdk-regulated gene, 17β-HSD2, were detected. The results uncover a previously unsuspected link between the cell cycle and hormone metabolism and differential roles for cdk6 and cdk4 in a novel mechanism for pre-receptor control of steroid hormone action, with important implications for the origin and treatment of steroid hormone-dependent cancers. PMID:24848372

Esculetin Attenuates the Growth of Lung Cancer by Downregulating Wnt Targeted Genes and Suppressing NF-κB.

PubMed

Zhu, Xiangyun; Gu, Jiaping; Qian, Hongxian

2018-03-01

Esculetin was identified to inhibit cell proliferation and induce apoptosis or cell cycle arrest in several cancer cell lines. However, the effect of esculetin on lung cancer remains elusive. The anti-proliferative role of esculetin in murine Lewis lung carcinoma (LLC) cells was evaluated by 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and colony formation assays. BALB/c mice were subcutaneously injected with LLC cells to investigate the inhibitory effect of esculetin on the growth of lung cancer xenograft. Invasive ability was detected in esculetin treated and untreated LLC cells by transwell assay. The association between esculetin and Wnt/β-catenin signaling, as well as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), was confirmed by testing the expression of c-myc, Cyclin D1 and NF-κB using Western blot. Esculetin treatment in LLC cells led to significant decrease of cell proliferation in a time- and dose-dependent manner. After injection of LLC cells into mice, reduced size and weight of tumors were observed in esculetin treated mice compared to untreated mice. However, no difference in cell invasion was observed between the treated and untreated LLC cells. Notably decreased expression of c-myc, Cyclin D1 and NF-κB were observed in LLC cells with esculetin treatment compared to untreated cells. Esculetin plays an inhibitory role in the growth of lung cancer by down-regulating c-myc, Cyclin D1 and NF-κB. Copyright © 2017 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.

Progesterone-induced miR-133a inhibits the proliferation of endometrial epithelial cells.

PubMed

Pan, J-L; Yuan, D-Z; Zhao, Y-B; Nie, L; Lei, Y; Liu, M; Long, Y; Zhang, J-H; Blok, L J; Burger, C W; Yue, L-M

2017-03-01

This study aimed to understand the role of miR-133a in progesterone actions, explore the regulative mechanism of the progesterone receptor, and investigate the effects of miR-133a on the progesterone-inhibited proliferation of mouse endometrial epithelial cells. The expression of miR-133a induced by progesterone was detected by quantitative real-time PCR both in vivo and in vitro. Ishikawa subcell lines stably transfected with progesterone receptor subtypes were used to determine the receptor mechanism of progesterone inducing miR-133a. Specific miR-133a mimics or inhibitors were transfected into mouse uteri and primary cultured endometrial epithelial cells to overexpress or downregulate the miR-133a. The roles of miR-133a in the cell cycle and proliferation of endometrial epithelial cells were analysed by flow cytometry and Edu incorporation analysis. The protein levels of cyclinD2 in uterine tissue sections and primary cultured endometrial epithelial cells were determined by immunohistochemistry and Western blot analysis. Progesterone could induce miR-133a expression in a PRB-dependent manner in endometrial epithelial cells. miR-133a inhibited endometrial epithelial cell proliferation by arresting cell cycle at the G 1 -S transition. Moreover, miR-133a acted as an inhibitor in downregulating cyclinD2 in endometrial epithelial cells. We showed for the first time that progesterone-induced miR-133a inhibited the proliferation of endometrial epithelial cells by downregulating cyclinD2. Our research indicated an important mechanism for progesterone inhibiting the proliferation of endometrial epithelial cells by inducing special miRNAs to inhibit positive regulatory proteins in the cell cycle. © 2016 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Upregulation of human DNA binding protein A (dbpA) in gastric cancer cells.

PubMed

Wang, Guo-rong; Zheng, Yan; Che, Xiang-ming; Wang, Xin-yang; Zhao, Jia-hui; Wu, Kai-jie; Zeng, Jin; Pan, Chen-en; He, Da-lin

2009-10-01

To determine the effect of human DNA binding protein (dbpA) on the biology of gastric cancer cells. DbpA expression was analyzed by Western blot analysis and immunofluorescence staining in gastric cancer tissues and cell lines. A dbpA-specific small interference (si) RNA was designed and synthesized. Suppressive effect of siRNA on dbpA expression was assessed by real-time RT-PCR. Transwell migration and colony formation assays were used to assess the inhibitory effects of dbpA siRNA on cell invasion and tumorigenesis in vitro. Drug-sensitivity was evaluated using a conventional 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The expression of dbpA was upregulated in gastric cancer tissues and cell lines as compared to adjacent normal tissues or gastric epithelial cells. siRNA treatment successfully silenced dbpA expression. Silencing of dbpA increased expression of E-cadherin, decreased expression of adenomatous polyposis coli (APC), beta-catenin and cyclin D1, but had no effect on expression of NF-kappaB. Silencing of dbpA also suppressed cell invasion and colony formation of SGC7901 cells, and enhanced their chemosensitivity to 5-fluorouracil. DbpA plays an important role in the pathogenesis and development of gastric cancer, and the process involves E-cadherin, APC, beta-catenin and cyclin D1. Silencing of dbpA might be a novel therapeutic strategy for increasing chemosensitivity to 5-fluorouracil in gastric cancer.

S phase entry causes homocysteine-induced death while ataxia telangiectasia and Rad3 related protein functions anti-apoptotically to protect neurons.

PubMed

Ye, Weizhen; Blain, Stacy W

2010-08-01

A major phenotype seen in neurodegenerative disorders is the selective loss of neurons due to apoptotic death and evidence suggests that inappropriate re-activation of cell cycle proteins in post-mitotic neurons may be responsible. To investigate whether reactivation of the G1 cell cycle proteins and S phase entry was linked with apoptosis, we examined homocysteine-induced neuronal cell death in a rat cortical neuron tissue culture system. Hyperhomocysteinaemia is a physiological risk factor for a variety of neurodegenerative diseases, including Alzheimer's disease. We found that in response to homocysteine treatment, cyclin D1, and cyclin-dependent kinases 4 and 2 translocated to the nucleus, and p27 levels decreased. Both cyclin-dependent kinases 4 and 2 regained catalytic activity, the G1 gatekeeper retinoblastoma protein was phosphorylated and DNA synthesis was detected, suggesting transit into S phase. Double-labelling immunofluorescence showed a 95% co-localization of anti-bromodeoxyuridine labelling with apoptotic markers, demonstrating that those cells that entered S phase eventually died. Neurons could be protected from homocysteine-induced death by methods that inhibited G1 phase progression, including down-regulation of cyclin D1 expression, inhibition of cyclin-dependent kinases 4 or 2 activity by small molecule inhibitors, or use of the c-Abl kinase inhibitor, Gleevec, which blocked cyclin D and cyclin-dependent kinase 4 nuclear translocation. However, blocking cell cycle progression post G1, using DNA replication inhibitors, did not prevent apoptosis, suggesting that death was not preventable post the G1-S phase checkpoint. While homocysteine treatment caused DNA damage and activated the DNA damage response, its mechanism of action was distinct from that of more traditional DNA damaging agents, such as camptothecin, as it was p53-independent. Likewise, inhibition of the DNA damage sensors, ataxia-telangiectasia mutant and ataxia telangiectasia and Rad3 related proteins, did not rescue apoptosis and in fact exacerbated death, suggesting that the DNA damage response might normally function neuroprotectively to block S phase-dependent apoptosis induction. As cell cycle events appear to be maintained in vivo in affected neurons for weeks to years before apoptosis is observed, activation of the DNA damage response might be able to hold cell cycle-induced death in check.

Nitric oxide-induced cytostasis and cell cycle arrest of a human breast cancer cell line (MDA-MB-231): Potential role of cyclin D1

PubMed Central

Pervin, Shehla; Singh, Rajan; Chaudhuri, Gautam

2001-01-01

DETA-NONOate, a nitric oxide (NO) donor, induced cytostasis in the human breast cancer cells MDA-MB-231, and the cells were arrested in the G1 phase of the cell cycle. This cytostatic effect of the NO donor was associated with the down-regulation of cyclin D1 and hypophosphorylation of the retinoblastoma protein. No changes in the levels of cyclin E or the catalytic partners of these cyclins, CDK2, CDK4, or CDK6, were observed. This NO-induced cytostasis and decrease in cyclin D1 was reversible for up to 48 h of DETA-NONOate (1 mM) treatment. DETA-NONOate (1 mM) produced a steady-state concentration of 0.5 μM of NO over a 24-h period. Synchronized population of the cells exposed to DETA-NONOate remained arrested at the G1 phase of the cell cycle whereas untreated control cells progressed through the cell cycle after serum stimulation. The cells arrested at the G1 phase after exposure to the NO donor had low cyclin D1 levels compared with the control cells. The levels of cyclin E and CDK4, however, were similar to the control cells. The decline in cyclin D1 protein preceded the decrease of its mRNA. This decline of cyclin D1 was due to a decrease in its synthesis induced by the NO donor and not due to an increase in its degradation. We conclude that down-regulation of cyclin D1 protein by DETA-NONOate played an important role in the cytostasis and arrest of these tumor cells in the G1 phase of the cell cycle. PMID:11248121

Silymarin induces cyclin D1 proteasomal degradation via its phosphorylation of threonine-286 in human colorectal cancer cells.

PubMed

Eo, Hyun Ji; Park, Gwang Hun; Song, Hun Min; Lee, Jin Wook; Kim, Mi Kyoung; Lee, Man Hyo; Lee, Jeong Rak; Koo, Jin Suk; Jeong, Jin Boo

2015-01-01

Silymarin from milk thistle (Silybum marianum) plant has been reported to show anti-cancer, anti-inflammatory, antioxidant and hepatoprotective effects. For anti-cancer activity, silymarin is known to regulate cell cycle progression through cyclin D1 downregulation. However, the mechanism of silymarin-mediated cyclin D1 downregulation still remains unanswered. The current study was performed to elucidate the molecular mechanism of cyclin D1 downregulation by silymarin in human colorectal cancer cells. The treatment of silymarin suppressed the cell proliferation in HCT116 and SW480 cells and decreased cellular accumulation of exogenously-induced cyclin D1 protein. However, silymarin did not change the level of cyclin D1 mRNA. Inhibition of proteasomal degradation by MG132 attenuated silymarin-mediated cyclin D1 downregulation and the half-life of cyclin D1 was decreased in the cells treated with silymarin. In addition, silymarin increased phosphorylation of cyclin D1 at threonine-286 and a point mutation of threonine-286 to alanine attenuated silymarin-mediated cyclin D1 downregulation. Inhibition of NF-κB by a selective inhibitor, BAY 11-7082 suppressed cyclin D1 phosphorylation and downregulation by silymarin. From these results, we suggest that silymarin-mediated cyclin D1 downregulation may result from proteasomal degradation through its threonine-286 phosphorylation via NF-κB activation. The current study provides new mechanistic link between silymarin, cyclin D1 downregulation and cell growth in human colorectal cancer cells. Copyright © 2014 Elsevier B.V. All rights reserved.

Role of Cyclin D1 and cdk Inhibitors in Breast Cancer Pathogenesis

DTIC Science & Technology

2001-10-01

0.1 [tg of a Renilla luciferase expression plasmid (pRL-SV40 Promega) to normalize for transfection efficiency. After an overnight recovery, the...saline, collected, lysed, and analyzed for luciferase and Renilla luciferase activity by using the Dual-Luciferase reporter assay system (Promega...Cyclin A promoter-driven luciferase activity was then normalized to a constant activity of Renilla luciferase. 7 Results In our previous reports we

BAG3 regulates cell proliferation, migration, and invasion in human colorectal cancer.

PubMed

Shi, Huiyong; Xu, Haidong; Li, Zengjun; Zhen, Yanan; Wang, Bin; Huo, Shoujun; Xiao, Ruixue; Xu, Zhongfa

2016-04-01

Bcl2-associated athanogene 3 (BAG3) has been reported to be elevated in various tumors. However, it is unclear whether BAG3 has a functional role in the initiation and progression of colorectal cancer (CRC). Here, we collected CRC samples and cell lines to validate the pathway by using gene and protein assays. RT-PCR showed that the expression of BAG3 mRNA in CRC tissues was obviously higher than that in non-tumor tissues (p < 0.001). Immunohistochemical analysis showed that immunoreactivity of BAG3 was found in most CRC tissues and strongly correlated with TNM stage (p = 0.001), differentiation (p = 0.003), and metastasis (p = 0.010). Low expression of BAG3 in HCT-8 significantly reduced cellular proliferation, migration, and invasion. The analysis of in vitro cell showed that HCT-8 cells were exposed to si-BAG3, and its growth was inhibited depending on modulation of cell cycle G1/S checkpoints and cell cycle regulators, involving cyclin D1, cyclin A2, and cyclin B1. Furthermore, suppression of the epithelial-mesenchymal transition (EMT) by si-BAG3 is linked to the decreased expression of E-cadherin and the increased expression of N-cadherin, vimentin, and MMP9. In conclusion, in the present study, we demonstrated that BAG3 overexpression plays a critical role in cell proliferation, migration, and invasion of colorectal cancer. Our data suggests targeted inhibition of BAG3 may be useful for patients with CRC.

Induction of miR-137 by Isorhapontigenin (ISO) Directly Targets Sp1 Protein Translation and Mediates Its Anticancer Activity Both In Vitro and In Vivo.

PubMed

Zeng, Xingruo; Xu, Zhou; Gu, Jiayan; Huang, Haishan; Gao, Guangxun; Zhang, Xiaoru; Li, Jingxia; Jin, Honglei; Jiang, Guosong; Sun, Hong; Huang, Chuanshu

2016-03-01

Our recent studies found that isorhapontigenin (ISO) showed a significant inhibitory effect on human bladder cancer cell growth, accompanied with cell-cycle G0-G1 arrest as well as downregulation of Cyclin D1 expression at transcriptional level via inhibition of Sp1 transactivation in bladder cancer cells. In the current study, the potential ISO inhibition of bladder tumor formation has been explored in a xenograft nude mouse model, and the molecular mechanisms underlying ISO inhibition of Sp1 expression and anticancer activities have been elucidated both in vitro and in vivo. Moreover, the studies demonstrated that ISO treatment induced the expression of miR-137, which in turn suppressed Sp1 protein translation by directly targeting Sp1 mRNA 3'-untranslated region (UTR). Similar to ISO treatment, ectopic expression of miR-137 alone led to G0-G1 cell growth arrest and inhibition of anchorage-independent growth in human bladder cancer cells, which could be completely reversed by overexpression of GFP-Sp1. The inhibition of miR-137 expression attenuated ISO-induced inhibition of Sp1/Cyclin D1 expression, induction of G0-G1 cell growth arrest, and suppression of cell anchorage-independent growth. Taken together, our studies have demonstrated that miR-137 induction by ISO targets Sp1 mRNA 3'-UTR and inhibits Sp1 protein translation, which consequently results in reduction of Cyclin D1 expression, induction of G0-G1 growth arrest, and inhibition of anchorage-independent growth in vitro and in vivo. Our results have provided novel insights into understanding the anticancer activity of ISO in the therapy of human bladder cancer. ©2016 American Association for Cancer Research.

Cyclin D1 and Cyclin E as Markers of Therapeutic Responsiveness in Breast Cancer

DTIC Science & Technology

2002-05-01

address whether cyclin D1 and cyclin E were predictive markers for therapeutic responsiveness in breast cancer. Both estrogen and progesterone ...although whether progesterone is tion of p 18 N K4c and increased association of the CDK stimulatory or inhibitory for normal breast epithelium remains...steroid progesterone and its synthetic ana- p2 7Ki pl and p21 ip 1 available to bind other proteins (8). Thus, logues, progestins, have complex effects

The mucin MUC4 and its membrane partner ErbB2 regulate biological properties of human CAPAN-2 pancreatic cancer cells via different signalling pathways.

PubMed

Jonckheere, Nicolas; Skrypek, Nicolas; Merlin, Johann; Dessein, Anne Frédérique; Dumont, Patrick; Leteurtre, Emmanuelle; Harris, Ann; Desseyn, Jean-Luc; Susini, Christiane; Frénois, Frédéric; Van Seuningen, Isabelle

2012-01-01

The mucin MUC4 and its membrane partner the ErbB2 oncogenic receptor are potential interacting partners in human pancreatic tumour development. However, the way they function is still largely unknown. In this work, we aimed to identify the cellular mechanisms and the intracellular signalling pathways under the control of both ErbB2 and MUC4 in a human pancreatic adenocarcinomatous cell line. Using co-immunoprecipitation and GST pull-down, we show that MUC4 and ErbB2 interact in the human pancreatic adenocarcinomatous cell line CAPAN-2 via the EGF domains of MUC4. Stable cell clones were generated in which either MUC4 or ErbB2 were knocked down (KD) by a shRNA approach. Biological properties of these cells were then studied in vitro and in vivo. Our results show that ErbB2-KD cells are more apoptotic and less proliferative (decreased cyclin D1 and increased p27kip1 expression) while migration and invasive properties were not altered. MUC4-KD clones were less proliferative with decreased cyclin D1 expression, G1 cell cycle arrest and altered ErbB2/ErbB3 expression. Their migration properties were reduced whereas invasive properties were increased. Importantly, inhibition of ErbB2 and MUC4 expression did not impair the same signalling pathways (inhibition of MUC4 expression affected the JNK pathway whereas that of ErbB2 altered the MAPK pathway). Finally, ErbB2-KD and MUC4-KD cells showed impaired tumour growth in vivo. Our results show that ErbB2 and MUC4, which interact physically, activate different intracellular signalling pathways to regulate biological properties of CAPAN-2 pancreatic cancer cells.

Pathogenic mutation in the ALS/FTD gene, CCNF, causes elevated Lys48-linked ubiquitylation and defective autophagy.

PubMed

Lee, Albert; Rayner, Stephanie L; Gwee, Serene S L; De Luca, Alana; Shahheydari, Hamideh; Sundaramoorthy, Vinod; Ragagnin, Audrey; Morsch, Marco; Radford, Rowan; Galper, Jasmin; Freckleton, Sarah; Shi, Bingyang; Walker, Adam K; Don, Emily K; Cole, Nicholas J; Yang, Shu; Williams, Kelly L; Yerbury, Justin J; Blair, Ian P; Atkin, Julie D; Molloy, Mark P; Chung, Roger S

2018-01-01

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are fatal neurodegenerative disorders that have common molecular and pathogenic characteristics, such as aberrant accumulation and ubiquitylation of TDP-43; however, the mechanisms that drive this process remain poorly understood. We have recently identified CCNF mutations in familial and sporadic ALS and FTD patients. CCNF encodes cyclin F, a component of an E3 ubiquitin-protein ligase (SCF cyclin F ) complex that is responsible for ubiquitylating proteins for degradation by the ubiquitin-proteasome system. In this study, we examined the ALS/FTD-causing p.Ser621Gly (p.S621G) mutation in cyclin F and its effect upon downstream Lys48-specific ubiquitylation in transfected Neuro-2A and SH-SY5Y cells. Expression of mutant cyclin F S621G caused increased Lys48-specific ubiquitylation of proteins in neuronal cells compared to cyclin F WT . Proteomic analysis of immunoprecipitated Lys48-ubiquitylated proteins from mutant cyclin F S621G -expressing cells identified proteins that clustered within the autophagy pathway, including sequestosome-1 (p62/SQSTM1), heat shock proteins, and chaperonin complex components. Examination of autophagy markers p62, LC3, and lysosome-associated membrane protein 2 (Lamp2) in cells expressing mutant cyclin F S621G revealed defects in the autophagy pathway specifically resulting in impairment in autophagosomal-lysosome fusion. This finding highlights a potential mechanism by which cyclin F interacts with p62, the receptor responsible for transporting ubiquitylated substrates for autophagic degradation. These findings demonstrate that ALS/FTD-causing mutant cyclin F S621G disrupts Lys48-specific ubiquitylation, leading to accumulation of substrates and defects in the autophagic machinery. This study also demonstrates that a single missense mutation in cyclin F causes hyper-ubiquitylation of proteins that can indirectly impair the autophagy degradation pathway, which is implicated in ALS pathogenesis.

The Role of Polycomb Group Gene BMI-1 in the Development of Prostate Cancer

DTIC Science & Technology

2010-09-01

2006 Jul 24;1:15. 17. Fu M, Wang C, Li Z, Sakamaki T, Pestell RG. Minireview: Cyclin D1: normal and abnormal functions. Endocrinology. 2004 Dec;145...and cyclin D1:connecting development to breast cancer. Cell Cycle. 2004 Feb;3(2):145-8. 32. Wang C, Li Z, Fu M, Bouras T, Pestell RG. Signal... Pestell R, Albanese C. ErbB-2 induces the cyclin D1 gene in prostate epithelial cells in vitro and in vivo. Cancer Res. 2007 May 1;67(9):4364-72. 36

Functional characterization of a human cyclin T1 mutant reveals a different binding surface for Tat and HEXIM1.

PubMed

Kuzmina, Alona; Hadad, Uzi; Fujinaga, Koh; Taube, Ran

2012-05-10

HIV transcription is regulated at the step of elongation by the viral Tat protein and the cellular positive transcription elongation factor b (P-TEFb; Cdk9/cyclin T1). Herein, a human cyclin T1 mutant, cyclin T1-U7, which contains four substitutions and one deletion in the N-terminal cyclin box, was stably expressed in HeLa cells. HIV transcription was efficiently inhibited in HeLa-HA-CycT1-U7 stable cells. Cyclin T1-U7 bound Tat but did not modulate its expression levels, which remained high. Importantly cyclin T1-U7 failed to interact with Cdk9 or HEXIM1 and did not interfere with endogenous P-TEFb activity to stimulate MEF2C or NFkB mediated transcription. In a T cell line and primary CD4+ cells, cyclin T1-U7 also inhibited HIV transcription. We conclude that cyclin T1-U7 sequesters Tat from P-TEFb and inhibits HIV transcription. Importantly, N-terminal residues in cyclin T1 are specifically involved in the binding of cyclin T1 to HEXIM1 but not to Tat. Copyright © 2012 Elsevier Inc. All rights reserved.

Experimental study on inhibitory effects of histone deacetylase inhibitor MS-275 and TSA on bladder cancer cells.

PubMed

Qu, Wei; Kang, Yin-Dong; Zhou, Mei-Sheng; Fu, Li-Li; Hua, Zhen-Hao; Wang, Li-Ming

2010-01-01

To investigate the inhibitory effect of histone deacetylase (HDAC) inhibitors (MS-275 and TSA) on T24 human bladder cancer cells in vitro, and explore the possible mechanism. The MTT assay was employed to evaluate the inhibitory effect of MS-275 and TSA on T24 cell growth. FCM was used to analyze the variation of T24 cell cycle distribution and the apoptotic ratio after T24 cells were treated with MS-275 and TSA. Histone acetylation level was detected by Western blot. mRNA expression of p21 WAF1/CIP1, cyclin A, and cyclin E was measured by FQ-PCR. Dynamic changes of Bcl-2 and bax expression were detected by FCM. MS-275 and TSA inhibited T24 cell growth in a concentration and time-dependent manner. Treatment with 4 μmol/l MS-275 or 0.4 μmol/l TSA blocked cell cycling in the G0/G1 phase and induced a significant increase in cell apoptosis. MS-275 and TSA significantly increased the level of histone acetylation, induced p21CIP1WAF1 mRNA expression, and inhibited cyclin A mRNA expression, though no significant effect was observed on cyclin E. Bcl-2 expression was down-regulated, while bax expression was up-regulated. HDAC inhibitors can block bladder cancer cell cycle in vitro and induce apoptosis. The molecular mechanism may be associated with increased level of histone acetylation, down-regulation of p21WAF1/CIP1 expression, up-regulation of cyclin A expression, and dynamic change of bcl-2 and bax expression. Copyright © 2010 Elsevier Inc. All rights reserved.

MicroRNA-195 inhibits proliferation of cervical cancer cells by targeting cyclin D1a.

PubMed

Wang, Ning; Wei, Heng; Yin, Duo; Lu, Yanming; Zhang, Yao; Zhang, Qiao; Ma, Xiaoxin; Zhang, Shulan

2016-04-01

Cervical cancer is one of the most frequent gynecological malignancies in women worldwide. MicroRNA-195 (miR-195) was recently found highly expressed in cervical cancer. However, the role of miR-195 in the pathology of cervical cancer remains poorly understood. In this study, we first confirmed the downregulation of miR-195 in primary cervical cancer tissues. For the functional study, we introduced the sequences of miR-195 or miR-195 inhibitor into Hela and SiHa cervical cancer cell lines. Overexpression of miR-195 inhibited the proliferation of both Hela and SiHa cells. In contrast, reducing the endogenous miR-195 level by miR-195 inhibitor promoted the proliferation of cervical cancer cells. Flow cytometric assay showed that overexpression of miR-195 induced G1 phase arrest, whereas miR-195 inhibitor shortened G1 phase of cervical cancer cells. In addition, the suppressive role of miR-195 in cell cycle was also demonstrated by the western blot results of various cell cycle indicators, such as phosphorylated retinoblastoma (p-Rb) and proliferating cell nuclear antigen (PCNA), in the gain and loss of function experiments. Furthermore, Dual-Luciferase Reporter Assay revealed that miR-195 targeted the 3'-untranslated region of cyclin D1a transcript, such as to regulate cyclin D1 expression. In summary, our results suggest that miR-195 acts as a suppressor in the proliferation and cell cycle of cervical cancer cells by directly targeting cyclin D1a mRNA.

Formononetin promotes cell cycle arrest via downregulation of Akt/Cyclin D1/CDK4 in human prostate cancer cells.

PubMed

Li, Tianyu; Zhao, Xinge; Mo, Zengnan; Huang, Weihua; Yan, Haibiao; Ling, Zhian; Ye, Yu

2014-01-01

Formononetin is an O-methylated isoflavone isolated from the root of Astragalus membranaceus. It has already been reported that formononetin could inhibit cell proliferation and induce cell apoptosis in several cancers, including prostate cancer. This study aimed to further investigate whether cell cycle arrest is involved in formononetin-mediated antitumor effect in human prostate cancer cells, along with the underlying molecular mechanism. Human prostate cancer cells PC-3 and DU145 were respectively treated with various concentrations of formononetin. The inhibitory effect of formononetin on proliferation of prostate cancer cells was determined using MTT assays and flow cytometry. Next, formononetin-induced alterations in cyclin D1, CDK4 and Akt expression in PC-3 cells were detected by real-time PCR and western blot. Formononetin dose-dependently inhibited prostate cancer cell proliferation via the induction of cell cycle arrest at G0/G1 phase in vitro, which was more evident in PC-3 cells. Meanwhile, concomitant with reduced phosphorylation of Akt in PC-3 cells, formononetin remarkably downregulated expression levels of cyclin D1 and CDK4 in a dose-dependent manner. More interestingly, in the in vivo studies, formononetin showed a noticeable inhibition of tumor growth in recipient mice. Formononetin could exhibit inhibitory activity against human prostate cancer cells in vivo and in vitro, which is associated with G1 cell cycle arrest by inactivation of Akt/cyclin D1/CDK4. Therefore, formononetin may be used as a candidate agent for clinical treatment of prostate cancer in the future.

Biomarkers in Advanced Larynx Cancer

PubMed Central

Bradford, Carol R.; Kumar, Bhavna; Bellile, Emily; Lee, Julia; Taylor, Jeremy; D’Silva, Nisha; Cordell, Kitrina; Kleer, Celina; Kupfer, Robbi; Kumar, Pawan; Urba, Susan; Worden, Francis; Eisbruch, Avraham; Wolf, Gregory T.; Teknos, Theodoros N.; Prince, Mark E.P.; Chepeha, Douglas B.; Hogikyan, Norman D.; Moyer, Jeffrey S.; Carey, Thomas E.

2014-01-01

Objectives/Hypothesis To determine if tumor biomarkers were predictive of outcome in a prospective cohort of patients with advanced larynx cancer treated in a phase II clinical trial. Study Design Prospectively collected biopsy specimens from 58 patients entered into a Phase II trial of organ preservation in advanced laryngeal cancer were evaluated for expression of a large panel of biomarkers and correlations with outcome were determined. Methods Tissue microarrays were constructed from pretreatment biopsies and stained for cyclin D1, CD24, EGFR, MDM2, PCNA, p53, survivin, Bcl-xL, Bcl-2, BAK, rhoC, and NFκB. Pattern of invasion and p53 mutations were assessed. Correlations with overall survival (OS), disease-specific survival (DSS), time free from indication of surgery, induction chemotherapy response, and chemoradiation response were determined. Cox models were used to assess combinations of these biomarkers. Results Low expression of BAK was associated with response to induction chemotherapy. Low expression of BAK and cytoplasmic NFκB was associated with chemoradiation response. Aggressive histologic growth pattern was associated with response induction chemotherapy. Expression of cyclin D1 was predictive of overall and disease-specific survival. Overexpression of EGFR was also associated with an increased risk of death from disease. Bcl-xL expression increased significantly in persistent/recurrent tumors specimens when compared to pretreatment specimens derived from the same patient (p = 0.0003). Conclusions Evaluation of biomarker expression in pretreatment biopsy specimens can lend important predictive and prognostic information for patients with advanced larynx cancer. PMID:23775802

CD59 Underlines the Antiatherosclerotic Effects of C-Phycocyanin on Mice

PubMed Central

Chu, Xian-Ming; Xu, Ying-Jie; Yang, Fan; Lv, Cong-Yi; Nie, Shu-min

2013-01-01

The effects of C-phycocyanin (C-PC) on atherosclerosis and the regulatory effects of CD59 gene on anti-atherosclerotic roles of C-PC were investigated. Apolipoprotein E knockout (ApoE(−/−)) mice were randomly divided into four groups: control group, C-PC treatment group, CD59 transfection group and C-PC+CD59 synergy group. The mice were fed with high-fat-diet and treated with drug intervention at the same time. Results showed the atherosclerotic mouse model was successfully established. CD59 was over-expressed in blood and tissue cells. Single CD59 or C-PC could reduce blood lipid levels and promote the expression of anti-apoptotic Bcl-2 but inhibit pro-apoptotic Fas proteins in endothelial cells. The expression levels of cell cycle protein D1 (Cyclin D1) and mRNA levels of cyclin dependent protein kinase 4 (CDK4) in smooth muscle cells were restrained by CD59 and C-PC. CD59 or C-PC alone could inhibit the formation of atherosclerotic plaque by suppressing MMP-2 protein expression. In addition, C-PC could promote CD59 expression. So both CD59 and C-PC could inhibit the progress of atherosclerosis, and the anti-atherosclerotic effects of C-PC might be fulfilled by promoting CD59 expression, preventing smooth muscle cell proliferation and the apoptosis of endothelial cells, reducing blood fat levels, and at last inhibiting the development of atherosclerosis. PMID:24319687

Misexpression of cyclin B3 leads to aberrant spermatogenesis.

PubMed

Refik-Rogers, Jale; Manova, Katia; Koff, Andrew

2006-09-01

Mus musculus cyclin B3 is an early meiotic cyclin that is expressed in leptotene and zygotene phases during gametogenesis. In order to determine whether downregulation of cyclin B3 at zygotene-pachytene transition was important for normal spermatogenesis, we investigated the consequences of expressing H. sapiens cyclin B3 after zygotene in mouse testes. Prolonging expression of cyclin B3 until the end of meiosis led to a reduction in sperm counts and disruption of spermatogenesis in four independent lines of transgenic mice. There were three distinct morphological defects associated with the ectopic expression of cyclin B3. Seminiferous tubules were either depleted of germ cells, had an abnormal cell mass in the lumen, or were characterized by the presence of abnormal round spermatids. These defects were associated with increased apoptosis in the testes. These results suggest that downregulation of cyclin B3 at the zygotene-pachytene transition is required to ensure normal spermatogenesis.

Low-molecular weight forms of cyclin E differentiate ovarian carcinoma from cells of mesothelial origin and are associated with poor survival in ovarian carcinoma.

PubMed

Davidson, Ben; Skrede, Martina; Silins, Ilvars; Shih, Ie-Ming; Trope, Claes G; Flørenes, Vivi Ann

2007-09-15

The authors recently reported on the role of cyclin E in differentiating ovarian/primary peritoneal carcinoma from malignant peritoneal mesothelioma using gene expression arrays. In the current study, they analyzed the expression of low-molecular weight (LMW) forms of cyclin E in ovarian carcinoma, malignant mesothelioma, and benign reactive effusions. Cyclin E protein expression was analyzed in 98 effusions (72 ovarian carcinomas, 14 malignant mesotheliomas, and 12 reactive specimens) using immunoblotting. Sixty-two ovarian carcinoma effusions were studied further for cyclin E expression using immunohistochemistry. The correlations between cyclin E expression in ovarian carcinoma and clinical parameters, including chemotherapy response, were analyzed. LMW forms of cyclin E were identified in 54 of 72 ovarian carcinoma effusions (75%) compared with 1 of 14 malignant mesothelioma effusions (7%) and 1 of 12 reactive effusions (8%) (P < .001). Their presence in ovarian carcinoma was associated with a higher percentage of cyclin E-positive cells (P = .001) and increased staining intensity (P < .001) using immunohistochemistry. The presence of LMW forms of cyclin E was correlated with shorter overall survival (P = .021) and progression-free survival (P = .020). The presence of a higher percentage of cyclin E-positive cells using immunohistochemistry was correlated with shorter progression-free survival (P = .026). No association with chemotherapy response was observed. LMW forms of cyclin E differentiated ovarian carcinoma from benign and malignant mesothelial cells and were associated with increased protein expression using immunohistochemistry. The expression of LMW cyclin E forms was not associated with chemotherapy response, although it may be a marker of aggressive disease in patients with metastatic ovarian carcinoma. (c) 2007 American Cancer Society.

Fra-1 promotes growth and survival in RAS-transformed thyroid cells by controlling cyclin A transcription

PubMed Central

Casalino, Laura; Bakiri, Latifa; Talotta, Francesco; Weitzman, Jonathan B; Fusco, Alfredo; Yaniv, Moshe; Verde, Pasquale

2007-01-01

Fra-1 is frequently overexpressed in epithelial cancers and implicated in invasiveness. We previously showed that Fra-1 plays crucial roles in RAS transformation in rat thyroid cells and mouse fibroblasts. Here, we report a novel role for Fra-1 as a regulator of mitotic progression in RAS-transformed thyroid cells. Fra-1 expression and phosphorylation are regulated during the cell cycle, peaking at G2/M. Knockdown of Fra-1 caused a proliferative block and apoptosis. Although most Fra-1-knockdown cells accumulated in G2, a fraction of cells entering M-phase underwent abortive cell division and exhibited hallmarks of genomic instability (micronuclei, lagging chromosomes and anaphase bridges). Furthermore, we established a link between Fra-1 and the cell-cycle machinery by identifying cyclin A as a novel transcriptional target of Fra-1. During the cell cycle, Fra-1 was recruited to the cyclin A gene (ccna2) promoter, binding to previously unidentified AP-1 sites and the CRE. Fra-1 also induced the expression of JunB, which in turn interacts with the cyclin A promoter. Hence, Fra-1 induction is important in thyroid tumorigenesis, critically regulating cyclin expression and cell-cycle progression. PMID:17347653

[Expression of CD10 in tumor-associated fibroblast of cancerized or recurrent colorectal adenomas].

PubMed

Zheng, Jiangjiang; Zhu, Yin; Li, Changshui; Li, Yinya; Nie, Qianqian; Zhu, Ziling; Deng, Hong

2016-05-25

Objective: To investigate the expression of CD10 in tumor-associated fibroblasts (TAF) in colorectal adenomas and its relation to cancerization and recurrence of adenoma. Methods: Tissue samples of low-grade adenoma ( n =50), high-grade adenoma ( n =50) and colorectal adenocarcinoma ( n =50) were collected, and tissue samples at the distal margin of corresponding colorectal lesions were taken as controls. The expression of CD10 in the stromal TAFs, and the expressions of β-catenin, Ki-67, p53 and CyclinD1 in tumor cells were detected by immunohistochemistry (Envision). The correlation of CD10 expression in stromal TAFs with the expressions of β-catenin, Ki-67, p53 and CyclinD1 in tumor cells was analyzed by Spearmen. One hundred samples of low-grade colorectal adenoma were collected, including 57 non-recurrent cases and 43 recurrent cases (16 cases of recurrent adenoma and 27 cases of recurrent adenocarcinoma); the expression of stromal TAF CD10 were determined and compared among groups. Results: There was no TAF in normal colorectal mucosa. The expression rates of TAF CD10 in low-grade adenoma, high-grade adenoma and colorectal adenocarcinoma were 22%, 50% and 78%, respectively (all P <0.05). The expression of Ki-67 and β-catenin in low-grade adenoma, high-grade adenoma, colorectal adenocarcinoma was on a rising trend (all P <0.01). The expression of CyclinD1 in high-grade adenoma was higher than that in colorectal adenocarcinoma and low-grade adenoma (all P >0.05). The expression of p53 in colorectal adenocarcinoma and high-grade adenoma was higher than that in low grade adenoma (all P <0.01). The expression of TAF CD10 was correlated with the expression of p53, Ki-67 and β-catenin-nucleus( r =0.264、0.307、0.320, all P <0.01),but not correlated with CyclinD1 and β-catenin-membrane ( r =0.012、-0.073, all P >0.05). The TAF CD10 level was significantly higher in low-grade adenoma with recurrence than that in those without recurrence ( P <0.05).The expression of CD10 in recurrent colorectal adenocarcinoma was higher than that in recurrent adenoma ( P <0.05). Conclusion: The expression of TAF CD10 is increased gradually in the process of adenoma-cancer, indicating that it may play an important role in the canceration of adenoma. Adenomas with high expression of CD10 TAF are likely to be recurrent and cancerized, and detection of TAF CD10 combined with p53, Ki-67 and β-catenin may be of value in predicting canceration or recurrence of colorectal adenoma.

CCDC106 promotes non-small cell lung cancer cell proliferation.

PubMed

Zhang, Xiupeng; Zheng, Qin; Wang, Chen; Zhou, Haijing; Jiang, Guiyang; Miao, Yuan; Zhang, Yong; Liu, Yang; Li, Qingchang; Qiu, Xueshan; Wang, Enhua

2017-04-18

Coiled-coil domain containing (CCDC) family members enhance tumor cell proliferation, and high CCDC protein levels correlate with unfavorable prognoses. Limited research demonstrated that CCDC106 may promote the degradation of p53/TP53 protein and inhibit its transactivity. The present study demonstrated that CCDC106 expression correlates with advanced TNM stage (P = 0.008), positive regional lymph node metastasis (P < 0.001), and poor overall survival (P < 0.001) in 183 non-small cell lung cancer cases. A549 and H1299 cells were selected as representative of CCDC106-low and CCDC106-high expressing cell lines, respectively. CCDC106 overexpression promoted A549 cell proliferation and xenograft tumor growth in nude mice, while siRNA-mediated CCDC106 knockdown inhibited H1299 cell proliferation. CCDC106 promoted AKT phosphorylation and upregulated the cell cycle-regulating proteins Cyclin A2 and Cyclin B1. Cell proliferation promoted by CCDC106 via Cyclin A2 and Cyclin B1 was rescued by treatment with the AKT inhibitor, LY294002. Our studies revealed that CCDC106 is associated with non-small cell lung cancer progression and unfavorable prognosis. CCDC106 enhanced Cyclin A2 and Cyclin B1 expression and promoted A549 and H1299 cell proliferation, which depended on AKT signaling. These results suggest that CCDC106 may be a novel target for lung cancer treatment.

Low-level laser irradiation promotes the proliferation and maturation of keratinocytes during epithelial wound repair.

PubMed

Sperandio, Felipe F; Simões, Alyne; Corrêa, Luciana; Aranha, Ana Cecília C; Giudice, Fernanda S; Hamblin, Michael R; Sousa, Suzana C O M

2015-10-01

Low-level laser therapy (LLLT) has been extensively employed to improve epithelial wound healing, though the exact response of epithelium maturation and stratification after LLLT is unknown. Thus, this study aimed to assess the in vitro growth and differentiation of keratinocytes (KCs) and in vivo wound healing response when treated with LLLT. Human KCs (HaCaT cells) showed an enhanced proliferation with all the employed laser energy densities (3, 6 and 12 J/cm(2) , 660 nm, 100 mW), together with an increased expression of Cyclin D1. Moreover, the immunoexpression of proteins related to epithelial proliferation and maturation (p63, CK10, CK14) all indicated a faster maturation of the migrating KCs in the LLLT-treated wounds. In that way, an improved epithelial healing was promoted by LLLT with the employed parameters; this improvement was confirmed by changes in the expression of several proteins related to epithelial proliferation and maturation. Immunofluorescent expression of cytokeratin 10 (red) and Cyclin D1 (green) in (A) Control keratinocytes and (B) Low-level laser irradiated cells. Blue color illustrates the nuclei of the cells (DAPI staining). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Protection of neurons from high glucose-induced injury by deletion of MAD2B

PubMed Central

Meng, Xianfang; Wang, Xiaolan; Tian, Xiujuan; Yang, Zhihua; Li, Man; Zhang, Chun

2014-01-01

Diabetic encephalopathy may lead to cognitive deficits in diabetic patients and diminish quality of life. It has been shown that protracted hyperglycaemia is directly associated with neuronal apoptosis, which is involved in diabetic encephalopathy. The anaphase-promoting complex (APC) is essential for the survival of post-mitotic neurons. In our previous study, we found that the mitotic arrest deficient protein MAD2B, one of APC inhibitors, was expressed in neurons in central nervous system. However, whether MAD2B is involved in hyperglycaemia-induced apoptosis and thus takes part in diabetic encephalopathy is still unknown. To address this issue, we first explored the expression of MAD2B and cyclin B1 detected by immunofluorescence and Western blot. It was found that hyperglycaemia remarkably increased the expression of MAD2B and accumulation of cyclin B1 in cortices of diabetes mellitus rat model and in cultured primary neurons. To further explore the role of MAD2B in hyperglycaemia-induced neuronal injury, we depleted MAD2B expression by a specifically targeted shRNA against MAD2B. We observed that MAD2B deficiency alleviated cyclin B1 expression and apoptotic neuronal death. These results demonstrate that MAD2B expression is the main culprit for accumulation of cyclin B1 and apoptosis in neurons under high glucose. Moreover, inhibition of the expression of MAD2B prevented neurons from entering an aberrant S phase that led differentiated neurons into apoptotic cell death. These results suggest that hyperglycaemia induced neuronal apoptosis through inducing expression of MAD2B, which represents a novel mechanism of diabetic encephalopathy. PMID:24444371

Estrogen and progesterone promote breast cancer cell proliferation by inducing cyclin G1 expression.

PubMed

Tian, J-M; Ran, B; Zhang, C-L; Yan, D-M; Li, X-H

2018-01-23

Breast cancer is the most common cause of cancer among women in most countries (WHO). Ovarian hormone disorder is thought to be associated with breast tumorigenesis. The present study investigated the effects of estrogen and progesterone administration on cell proliferation and underlying mechanisms in breast cancer MCF-7 cells. It was found that a single administration of estradiol (E2) or progesterone increased MCF-7 cell viability in a dose-dependent manner and promoted cell cycle progression by increasing the percentage of cells in the G2/M phase. A combination of E2 and progesterone led to a stronger effect than single treatment. Moreover, cyclin G1 was up-regulated by E2 and/or progesterone in MCF-7 cells. After knockdown of cyclin G1 in MCF-7 cells using a specific shRNA, estradiol- and progesterone-mediated cell viability and clonogenic ability were significantly limited. Additionally, estradiol- and progesterone-promoted cell accumulation in the G2/M phase was reversed after knockdown of cyclin G1. These data indicated that estrogen and progesterone promoted breast cancer cell proliferation by inducing the expression of cyclin G1. Our data indicated that novel therapeutics against cyclin G1 are promising for the treatment of estrogen- and progesterone-mediated breast cancer progression.

The effect of myostatin on proliferation and lipid accumulation in 3T3-L1 preadipocytes.

PubMed

Zhu, Hui Juan; Pan, Hui; Zhang, Xu Zhe; Li, Nai Shi; Wang, Lin Jie; Yang, Hong Bo; Gong, Feng Ying

2015-06-01

Myostatin is a critical negative regulator of skeletal muscle development, and has been reported to be involved in the progression of obesity and diabetes. In the present study, we explored the effects of myostatin on the proliferation and differentiation of 3T3-L1 preadipocytes by using 3-[4,5-dimethylthiazol-2-yl] 2,5-diphenyl tetrazolium bromide spectrophotometry, intracellular triglyceride (TG) assays, and real-time quantitative RT-PCR methods. The results indicated that recombinant myostatin significantly promoted the proliferation of 3T3-L1 preadipocytes and the expression of proliferation-related genes, including Cyclin B2, Cyclin D1, Cyclin E1, Pcna, and c-Myc, and IGF1 levels in the medium of 3T3-L1 were notably upregulated by 35.2, 30.5, 20.5, 33.4, 51.2, and 179% respectively (all P<0.01) in myostatin-treated 3T3-L1 cells. Meanwhile, the intracellular lipid content of myostatin-treated cells was notably reduced as compared with the non-treated cells. Additionally, the mRNA levels of Pparγ, Cebpα, Gpdh, Dgat, Acs1, Atgl, and Hsl were significantly downregulated by 22-76% in fully differentiated myostatin-treated adipocytes. Finally, myostatin regulated the mRNA levels and secretion of adipokines, including Adiponectin, Resistin, Visfatin, and plasminogen activator inhibitor-1 (PAI-1) in 3T3-L1 adipocytes (all P<0.001). Above all, myostatin promoted 3T3-L1 proliferation by increasing the expression of cell-proliferation-related genes and by stimulating IGF1 secretion. Myostatin inhibited 3T3-L1 adipocyte differentiation by suppressing Pparγ and Cebpα expression, which consequently deceased lipid accumulation in 3T3-L1 cells by inhibiting the expression of critical lipogenic enzymes and by promoting the expression of lipolytic enzymes. Finally, myostatin modulated the expression and secretion of adipokines in fully differentiated 3T3-L1 adipocytes. © 2015 Society for Endocrinology.

Plant-originated glycoprotein (24 kDa) has an inhibitory effect on proliferation of BNL CL.2 cells in response to di(2-ethylhexyl)phthalate.

PubMed

Lee, Jin; Lim, Kye-Taek

2011-08-01

Di(2-ethylhexyl)phthalate (DEHP) is one of the many environmental chemicals that are widely used in polyvinyl chloride products, vinyl flooring, food packaging and infant toys. They cause cell proliferation or dysfunction of human liver. The purpose of this study is to investigate the inhibitory effect of a glycoprotein (24 kDa) isolated from Zanthoxylum piperitum DC (ZPDC) on proliferation of liver cell in the DEHP-induced BNL CL. 2 cells. [³H]-thymidine incorporation, intracellular reactive oxygen species (ROS), intracellular Ca²⁺ mobilization and activity of protein kinase C (PKC) were measured using radioactivity and fluorescence method respectively. The expression of mitogen-activated protein kinases [extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK)], activator protein (AP)-1 (c-Jun and c-Fos), proliferating cell nuclear antigen (PCNA) and cell cycle-related factors (cyclin D1/cyclin-dependent kinase [CDK] 4) were evaluated using Western blotting or electrophoretic mobility shift assay. The results in this study showed that the levels of [³H]-thymidine incorporation, intracellular ROS, intracellular Ca²⁺ mobilization and activity of PKCα were inhibited by ZPDC glycoprotein (100 µg/ml) in the DEHP-induced BNL CL. 2 cells. Also, activities of ERK, JNK and AP-1 were reduced by ZPDC glycoprotein (100 µg/ml). With regard to cell proliferation, activities of PCNA and cyclin D1/CDK4 were significantly suppressed at treatment with ZPDC glycoprotein (100 µg/ml) in the presence of DEHP. Taken together, these findings suggest that ZPDC glycoprotein significantly normalized activities of PCNA and cyclin D1/CDK4, which relate to cell proliferation factors. Thus, ZPDC glycoprotein appears to be one of the compounds derived from natural products that are able to inhibit cell proliferation in the phthalate-induced BNL CL. 2 cells. Copyright © 2011 John Wiley & Sons, Ltd.

17β-Estradiol regulates cyclin A1 and cyclin B1 gene expression in adult rat seminiferous tubules.

PubMed

Bois, Camille; Delalande, Christelle; Bouraïma-Lelong, Hélène; Durand, Philippe; Carreau, Serge

2012-04-01

Spermatogenesis, which is the fundamental mechanism allowing male gamete production, is controlled by several factors, and among them, estrogens are likely concerned. In order to enlighten the potential role of estrogen in rat spermatogenesis, seminiferous tubules (ST) from two groups of seminiferous epithelium stages (II-VIII and IX-I) were treated with either 17β-estradiol (E(2)) agonists or antagonists for estrogen receptors (ESRs). In this study, we show that cyclin A1 and cyclin B1 gene expression is controlled by E(2) at a concentration of 10(-9) M only in stages IX-I. This effect is mimicked by a treatment with the G-protein coupled estrogen receptor (GPER) agonist G1 and is abolished by treatment with the ESR antagonist ICI 182 780. Moreover, using letrozole, a drug that blocks estrogen synthesis, we demonstrate that these genes are under the control of E(2) within rat ST. Thus, germ cell differentiation may be regulated by E(2) which acts through ESRs and GPER, expressed in adult rat ST.

IL-35 promotes pancreas cancer growth through enhancement of proliferation and inhibition of apoptosis: evidence for a role as an autocrine growth factor.

PubMed

Nicholl, Michael B; Ledgewood, Chelsea L; Chen, Xuhui; Bai, Qian; Qin, Chenglu; Cook, Kathryn M; Herrick, Elizabeth J; Diaz-Arias, Alberto; Moore, Bradley J; Fang, Yujiang

2014-12-01

Interleukin-35 (IL-35), an IL-12 cytokine family member, mediates the immune inhibitory function of regulatory T cells (Treg). We assayed the presence of IL-35 in paraffin-embedded human pancreas cancer (PCAN) and unexpectedly found IL-35 was expressed mainly by epithelial derived PCAN cells, but not by Treg. We further examined the expression and effect of exogenous IL-35 in human PCAN cell lines and found IL-35 promoted growth and inhibited apoptosis in PCAN cell lines. IL-35 induced proliferation correlated with an increase in cyclin B, cyclin D, cdk2, and cdk4 and a decrease in p27 expression, while inhibition of apoptosis was associated with an increase in Bcl-2 and a decrease in TRAILR1. We conclude IL-35 is produced by PCAN in vivo and promotes PCAN cell line growth in vitro. These results might indicate an important new role for IL-35 as an autocrine growth factor in PCAN growth. Copyright © 2014 Elsevier Ltd. All rights reserved.

Downregulation of microRNA-33a promotes cyclin-dependent kinase 6, cyclin D1 and PIM1 expression and gastric cancer cell proliferation

PubMed Central

WANG, YUDONG; ZHOU, XINLIANG; SHAN, BAOEN; HAN, JING; WANG, FEIFEI; FAN, XIAOJIE; LV, YALEI; CHANG, LIANG; LIU, WEI

2015-01-01

Although microRNA-33 (miR-33) family members are known to be involved in the regulation and balancing of cholesterol metabolism, fatty acid oxidation and insulin signaling, their functions in carcinogenesis are controversial and the underlying mechanisms have remained elusive. Gastric cancer is the fourth most common malignancy in the world; however, the dysregulation and function of miR-33 family members in gastric cancer have not been extensively studied. The present study reported that a miR-33 family member, miR-33a, was significantly downregulated in gastric cancer tissues and gastric cancer cell lines. Of note, the expression of miR-33a was inversely correlated with pathological differentiation and metastasis as well as gastric cancer biomarker CA199. A cell-counting kit-8 assay showed that transfection of the SGC-7901 gastric cell line with miR-33a-overexpression plasmid inhibited the capability of the cells to proliferate. Furthermore, overexpression of miR-33a led to cell cycle arrest of SGC-7901 cells in G1 phase. In addition, a luciferase reporter assay showed that miR-33a directly targeted cyclin-dependent kinase 6 (CDK6), cyclin D1 (CCND1) and serine/threonine kinase PIM-1. In gastric cancer specimens, the reduced expression of miR-33a was associated with increased expression of CDK-6, CCND1 and PIM1. However, only PIM1 expression was significantly increased in cancer tissues compared with that in their adjacent tissues. The present study revealed that miR-33a was downregulated in gastric cancer tissues and cell lines, while forced overexpression of miR-33a decreased CDK-6, CCND1 and PIM1 expression to inhibit gastric cancer cell proliferation by causing G1 phase arrest. miR-33a overexpression may therefore resemble an efficient strategy for gastric cancer therapy. PMID:26352175

The Role of Polycomb Group Gene Bmi-1 in the Development of Prostate Cancer

DTIC Science & Technology

2011-09-01

new tricks. Cell Div. 2006 Jul 24;1:15. 17. Fu M, Wang C, Li Z, Sakamaki T, Pestell RG. Minireview: Cyclin D1: normal and abnormal functions... Pestell RG. Signal transduction mediated by cyclin D1: from mitogens to cell proliferation: a molecular target with therapeutic potential. Cancer...Datar 22 R, Cote R, Pestell R, Albanese C. ErbB-2 induces the cyclin D1 gene in prostate epithelial cells in vitro and in vivo. Cancer Res. 2007

Increased expression of cyclin B1 mRNA coincides with diminished G{sub 2}-phase arrest in irradiated HeLa cells treated with staurosporine or caffeine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernhard, E.J.; Maity, A.; McKenna, W.G.

1994-12-01

The irradiation of cells results in delayed progression through the G{sub 2} phase of the cell cycle. Treatment of irradiated HeLa cells with caffeine greatly reduces the G{sub 2}-phase delay, while caffeine does not alter progression of cells through the cell cycle in unirradiated cells. In this report we demonstrate that treatment of HeLa cells with the kinase inhibitor staurosporine, but not with the inhibitor H7, also results in a reduction of the G{sub 2}-phase arrest after irradiation. Cell cycle progression in unirradiated cells is unaffected by 4.4 nM (2ng/ml) staurosporine, which releases the radiation-induced G{sub 2}-phase arrest. In HeLamore » cells, the G{sub 2}-phase delay after irradiation in S phase is accompanied by decreased expression of cyclin B1 mRNA. Coincident with the reduction in G{sub 2}-phase delay, we observed an increase in cyclin B1 mRNA accumulation in irradiated, staurosporine-treated cells compared to cells treated with irradiation alone. Caffeine treatment of irradiated HeLa cells also resulted in an elevation in the levels of cyclin B1 message. These results support the hypothesis that diminished cyclin B1 mRNA levels influence G{sub 2}-phase arrest to some degree. The findings that both staurosporine and caffeine treatments reverse the depression in cyclin B1 expression suggest that these two compounds may act on a common pathway of cell cycle control in response to radiation injury. 33 refs., 6 figs.« less

Isolating of Target Genes for NKX3.1 in Prostate Carcinogenesis

DTIC Science & Technology

2005-03-01

stainin on e te o tesr prostate hist log .(Band - . (C a .. ( 2 (M -P) Ki6 s shows . celula pr lf rto in c( ssi Fg1.prosthate cane r progresin is enh...prostate tumorigenicity. s{ LA Finally, to assess the significance of Cyclin D1 for prostatea ,. 0 tumorigenicity, we used RNAi to knock-down its expression

Fbw7α and Fbw7γ Collaborate To Shuttle Cyclin E1 into the Nucleolus for Multiubiquitylation

PubMed Central

Bhaskaran, Nimesh; van Drogen, Frank; Ng, Hwee-Fang; Kumar, Raman; Ekholm-Reed, Susanna; Peter, Matthias

2013-01-01

Cyclin E1, an activator of cyclin-dependent kinase 2 (Cdk2) that promotes replicative functions, is normally expressed periodically within the mammalian cell cycle, peaking at the G1-S-phase transition. This periodicity is achieved by E2F-dependent transcription in late G1 and early S phases and by ubiquitin-mediated proteolysis. The ubiquitin ligase that targets phosphorylated cyclin E is SCFFbw7 (also known as SCFCdc4), a member of the cullin ring ligase (CRL) family. Fbw7, a substrate adaptor subunit, is expressed as three splice-variant isoforms with different subcellular distributions: Fbw7α is nucleoplasmic but excluded from the nucleolus, Fbw7β is cytoplasmic, and Fbw7γ is nucleolar. Degradation of cyclin E in vivo requires SCF complexes containing Fbw7α and Fbw7γ, respectively. In vitro reconstitution showed that the role of SCFFbw7α in cyclin E degradation, rather than ubiquitylation, is to serve as a cofactor of the prolyl cis-trans isomerase Pin1 in the isomerization of a noncanonical proline-proline bond in the cyclin E phosphodegron. This isomerization is required for subsequent binding and ubiquitylation by SCFFbw7γ. Here we show that Pin1-mediated isomerization of the cyclin E phosphodegron and subsequent binding to Fbw7γ drive nucleolar localization of cyclin E, where it is ubiquitylated by SCFFbw7γ prior to its degradation by the proteasome. It is possible that this constitutes a mechanism for rapid inactivation of phosphorylated cyclin E by nucleolar sequestration prior to its multiubiquitylation and degradation. PMID:23109421

Enhancer of zeste homolog 2 expression is associated with tumor cell proliferation and metastasis in gastric cancer.

PubMed

Choi, Jung Hye; Song, Young Soo; Yoon, Jin Sun; Song, Kang Won; Lee, Young Yiul

2010-03-01

The enhancer of zeste homolog 2 (EZH2), a member of the polycomb group of proteins, plays an important role in cell proliferation and cell cycle regulation. EZH2 is overexpressed in aggressive forms of prostate, breast, bladder, and endometrial cancers. However, the role of EZH2 expression in gastric cancer has not been fully determined. This study was conducted to investigate the correlation between EZH2 and cell cycle-related molecules, and the clinical value of EZH2 expression in gastric cancer. We analyzed EZH2 expression using Western blotting in AGS, MKN-28, SNU-16, SNU-484, SNU-601, and SNU-638 gastric cancer cell lines. After transfection of EZH2 siRNA into MKN-28 cells, the change in cell cycle-related molecules was assessed by Western blot analysis. Expression of EZH2, Ki-67, and p53 was determined by immunohistochemical staining of tissue microarrays from specimens of 137 cases of resected gastric cancer. We found high expressions of EZH2 in all of the tested gastric cancer cell lines. RNA interference of EZH2 induced upregulation of p53 and HDAC1 and downregulation of cyclin D1 and cyclin E. High EZH2 expression was observed in 60.6% of gastric cancers and in 6.7% of non-neoplastic gastric tissues (p < 0.01); 40.1% were positive for p53 in gastric cancers. High EZH2 expression was correlated with Ki-67 and p53 expressions and was significantly associated with distant metastases and non-signet ring cells. Our results suggest that high EZH2 expression is associated with tumor cell proliferation and metastasis in gastric cancer.

Cyclophilin J Is a Novel Peptidyl-Prolyl Isomerase and Target for Repressing the Growth of Hepatocellular Carcinoma

PubMed Central

Chen, Jian; Chen, Shuai; Wang, Jiahui; Zhang, Mingjun; Gong, Zhaohua; Wei, Youheng; Li, Li; Zhang, Yuanyuan; Zhao, Xuemei; Jiang, Songmin; Yu, Long

2015-01-01

Cyclophilin J (CYPJ) is a new member of the peptidyl-prolyl cis/trans-isomerase (PPIase) identified with upregulated expression in human glioma. However, the biological function of CYPJ remained unclear. We aimed to study the role of CYPJ in hepatocellular carcinoma (HCC) carcinogenesis and its therapeutic potential. We determined the expression of CYPJ in HCC/adjacent normal tissues using Western blot, Northern blot and semi-quantitative RT-PCR, analyzed the biochemical characteristics of CYPJ, and resolved the 3D-structure of CYPJ/Cyclosporin A (CsA) complex. We also studied the roles of CYPJ in cell cycle, cyclin D1 regulation, in vitro and in vivo tumor growth. We found that CYPJ expression was upregulated in over 60% HCC tissues. The PPIase activity of CYPJ could be inhibited by the widely used immunosuppressive drug CsA. CYPJ was found expressed in the whole cell of HCC with preferential location at the cell nucleus. CYPJ promoted the transition of cells from G1 phase to S phase in a PPIase-dependent manner by activating cyclin D1 promoter. CYPJ overexpression accelerated liver cell growth in vitro (cell growth assay, colony formation) and in vivo (xenograft tumor formation). Inhibition of CYPJ by its inhibitor CsA or CYPJ-specific RNAi diminished the growth of liver cancer cells in vitro and in vivo. In conclusion, CYPJ could facilitate HCC growth by promoting cell cycle transition from G1 to S phase through the upregulation of cyclin D1. Suppression of CYPJ could repress the growth of HCC, which makes CYPJ a potential target for the development of new strategies to treat this malignancy. PMID:26020957

The Role of SF2 in Prostate Cancer Progression

DTIC Science & Technology

2011-04-01

4 INTRODUCTION Background/Subject: Prostate cancer (PCa) is one of the most prevalent non-cutaneous cancers in men and the second...focused on the identification of PCa cell model systems and their subsequent manipulation of SF2 and cyclin D1 to mimic human disease (Subaim 1). The...Subaim 1: Generate PCa cells to mimic human disease. Summary: Preliminary data, in the initial Proposal, from a publically available gene expression

Insulin like growth factor 2 regulation of aryl hydrocarbon receptor in MCF-7 breast cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tomblin, Justin K.; Salisbury, Travis B., E-mail: salisburyt@marshall.edu

2014-01-17

Highlights: •IGF-2 stimulates concurrent increases in AHR and CCND1 expression. •IGF-2 promotes the binding of AHR to the endogenous cyclin D1 promoter. •AHR knockdown inhibits IGF-2 stimulated increases in CCND1 mRNA and protein. •AHR knockdown inhibits IGF-2 stimulated increases in MCF-7 proliferation. -- Abstract: Insulin like growth factor (IGF)-1 and IGF-2 stimulate normal growth, development and breast cancer cell proliferation. Cyclin D1 (CCND1) promotes cell cycle by inhibiting retinoblastoma protein (RB1). The aryl hydrocarbon receptor (AHR) is a major xenobiotic receptor that also regulates cell cycle. The purpose of this study was to investigate whether IGF-2 promotes MCF-7 breast cancermore » proliferation by inducing AHR. Western blot and quantitative real time PCR (Q-PCR) analysis revealed that IGF-2 induced an approximately 2-fold increase (P < .001) in the expression of AHR and CCND1. Chromatin immunoprecipitation (ChIP), followed by Q-PCR indicated that IGF-2 promoted (P < .001) a 7-fold increase in AHR binding on the CCND1 promoter. AHR knockdown significantly (P < .001) inhibited IGF-2 stimulated increases in CCND1 mRNA and protein. AHR knockdown cells were less (P < .001) responsive to the proliferative effects of IGF-2 than control cells. Collectively, our findings have revealed a new regulatory mechanism by which IGF-2 induction of AHR promotes the expression of CCND1 and the proliferation of MCF-7 cells. This previously uncharacterized pathway could be important for the proliferation of IGF responsive cancer cells that also express AHR.« less

Mapping of CIP/KIP inhibitors, G1 cyclins D1, D3, E and p53 proteins in the rat term placenta.

PubMed

Korgun, Emin Turkay; Unek, Gozde; Herrera, Emilio; Jones, Carolyn J; Wadsack, Christian; Kipmen-Korgun, Dijle; Desoye, Gernot

2011-09-01

As cell cycle regulation is fundamental to the normal growth and development of the placenta, the aim of the present study was to determine the immunolocalizations of cell cycle related proteins, which have key roles in proliferation, differentiation and apoptosis during the development of the rat placenta. Here immunohistochemistry has been used to localize G1 cyclins (D1, D3, E), which are major determinants of proliferation, CIP/KIP inhibitors (p21, p27, p57), p53 as a master regulator and proliferating cell nuclear antigen in all cell types of the rat term placenta. The proportion of each cell type immunolabeled was counted. Cyclin D1 and cyclin D3 were present mostly in cells of the fetal aspect of the placenta, whereas the G1/S cyclin E was present only in the spongio- and labyrinthine trophoblast populations. Among the CIP/KIP inhibitors, p21 was present only in cells of the fetal aspect whereas p27 and p57 were found in all cell types studied. p53 was only found in a small proportion of cells with no co-localization of p53 and p21. The data suggest that the cells of the fetal side of the rat placenta still have some proliferation potential which is kept in check by expression of the CIP/KIP cell cycle inhibitors, whereas cells of the maternal aspect have lost this potential. Apoptosis is only marginal in the term rat placenta. In conclusion, proliferation and apoptosis in rat placental cells appears controlled mostly by the CIP/KIP inhibitors in late pregnancy.

Prognostic significance of CCND1 (cyclin D1) overexpression in primary resected non-small-cell lung cancer.

PubMed Central

Betticher, D. C.; Heighway, J.; Hasleton, P. S.; Altermatt, H. J.; Ryder, W. D.; Cerny, T.; Thatcher, N.

1996-01-01

Amplification of the CCDN1 gene encoding cyclin D1 was examined by Southern blotting and multiplex polymerase chain reaction (PCR) and occurred in 8 of 53 patients (15%) with primary resected non-small-cell lung cancer (NSCLC). These tumours and 17 additional tumours with a normal gene copy number showed overexpression of cyclin D1 (25/53, 47%), as assessed by immunostaining using a monoclonal antibody. In 22/25 cases, cyclin D1 was localised in the cytoplasm, but some (7/25) had simultaneous nuclear staining. This result is in marked contrast to that reported in breast, hepatocellular and colorectal carcinoma studies where immunostaining was invariably nuclear. Examination of a restriction fragment length polymorphic (RFLP) site within the 3'untranslated region of the cDNA following reverse transcriptase (RT)-PCR (29/53 informative cases) showed a strong association between cytoplasmic staining and imbalance in allele-specific message levels. Cyclin D1 overexpression was associated with a poorly differentiated histology (P = 0.04), less lymphocytic infiltration of the tumour (P = 0.02) and a reduction in local relapse rate (P = 0.01). The relative risk of local relapse was 9.1 in tumours without cyclin D1 overexpression (P = 0.01, Cox regression analysis). We conclude that genetic alteration of cyclin D1 is a key abnormality in lung carcinogenesis and may have diagnostic and prognostic importance in the treatment of resectable NSCLC. Images Figure 1 Figure 2 Figure 3 PMID:8562333

Plasmin-clipped beta(2)-glycoprotein-I inhibits endothelial cell growth by down-regulating cyclin A, B and D1 and up-regulating p21 and p27.

PubMed

Beecken, Wolf-Dietrich C; Ringel, Eva Maria; Babica, Jan; Oppermann, Elsie; Jonas, Dietger; Blaheta, Roman A

2010-10-28

beta(2)-Glycoprotein-I (beta(2)gpI), an abundant plasma glycoprotein, functions as a regulator of thrombosis. Previously, we demonstrated that plasmin-clipped beta(2)gpI (cbeta(2)gpI) exerts an anti-angiogenic effect on human umbilical vein endothelial cells (HUVEC). The present study was focused on the molecular background responsible for this phenomenon. cbeta(2)gpI strongly reduced HUVEC growth and proliferation as evidenced by the MTT and BrdU assay and delayed cell cycle progression arresting HUVEC in the S-and G2/M-phase. Western blot analysis indicated that cbeta(2)gpI inhibited cyclin A, B and D1, and enhanced p21 and p27 expression. Activity of p38 was down-regulated independently from the cbeta(2)gpI incubation time. Phosphorylation of ERK1/2 was not changed early (30 and 60 min) but became enhanced later (90 min, 4h). JNK activity was reduced rapidly after cbeta(2)gpI treatment but compared to controls, increased thereafter. Annexin II blockade prevented growth inhibition and cell cycle delay evoked by cbeta(2)gpI. We assume that cbeta(2)gpI's effects on HUVEC growth is mediated via cyclin A, B and D1 suppression, up-regulation of p21 and p27 and coupled to modifications of the mitogen-activated protein (MAP) kinase signalling pathway. cbeta(2)gpI may represent a potential endogenous angiogenesis-targeted compound, opening the possibility of a novel tool to treat cancer. 2010 Elsevier Ireland Ltd. All rights reserved.

PRMT5 is essential for the eIF4E-mediated 5′-cap dependent translation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lim, Ji-Hong; Lee, Yoon-Mi; Lee, Gibok

2014-10-03

Highlights: • PRMT5 participates in syntheses of HIF-1α, c-Myc and cyclin D1 proteins. • PRMT5 promotes the 5′-cap dependent translation. • PRMT5 is required for eIF4E binding to mRNA 5′-cap. • PRMT5 is essential for eIF4E-dependent cell proliferation. - Abstract: It is becoming clear that PRMT5 plays essential roles in cell cycle progression, survival, and responses to external stresses. However, the precise mechanisms underlying such roles of PRMT5 have not been clearly understood. Previously, we have demonstrated that PRMT5 participates in cellular adaptation to hypoxia by ensuring 5′-cap dependent translation of HIF-1α. Given that c-Myc and cyclin D1 expressions aremore » also tightly regulated in 5′-cap dependent manner, we here tested the possibility that PRMT5 promotes cell proliferation by increasing de novo syntheses of the oncoproteins. c-Myc and cyclin D1 were found to be noticeably downregulated by PRMT5 knock-down. A RNA immunoprecipitation analysis, which can identify RNA–protein interactions, showed that PRMT5 is required for the interaction among eIF4E and 5′-UTRs of HIF-1α, c-Myc and cyclin D1 mRNAs. In addition, PRMT5 knock-down inhibited cell proliferation by inducing cell cycle arrest at the G1 phase. More importantly, ectopic expression of eIF4E significantly rescued the cell cycle progression and cell proliferation even in PRMT5-deficeint condition. Based on these results, we propose that PRMT5 determines cell fate by regulating 5′-cap dependent translation of proteins essential for proliferation and survival.« less

Deregulated expression of p16INK4a and p53 pathway members in benign and malignant myoepithelial tumours of the salivary glands.

PubMed

Vékony, H; Röser, K; Löning, T; Raaphorst, F M; Leemans, C R; Van der Waal, I; Bloemena, E

2008-12-01

Myoepithelial salivary gland tumours are uncommon and follow an unpredictable biological course. The aim was to examine their molecular background to acquire a better understanding of their clinical behaviour. Expression of protein (E2F1, p16(INK4a), p53, cyclin D1, Ki67 and Polycomb group proteins BMI-1, MEL-18 and EZH2) was investigated in 49 benign and 30 primary malignant myoepithelial tumours and five histologically benign recurrences by immunohistochemistry and the findings correlated with histopathological characteristics. Benign tumours showed a higher percentage of cells with expression of p16(INK4a) pathway members [p16(INK4a) and E2F1 (both P < 0.001), and cyclin D1, P = 0.002] compared with normal salivary gland. Furthermore, malignant tumours expressed p53 (P = 0.003) and EZH2 (P = 0.09) in a higher percentage. Recurrences displayed more p53 + tumour cells (P = 0.02) than benign primaries. Amongst the benign tumours, the clear cell type had the highest proliferation fraction (P = 0.05) and a higher percentage of EZH2 was detected in the plasmacytoid cell type (P = 0.002). This study is the first to demonstrate that deregulation of the p16(INK4a) senescence pathway is involved in the development of myoepithelial tumours. We propose that additional inactivation of p53 in malignant primaries and benign recurrences contributes to myoepithelial neoplastic transformation and aggressive tumour growth.

Expression of p53, p21 and cyclin D1 in penile cancer: p53 predicts poor prognosis.

PubMed

Gunia, Sven; Kakies, Christoph; Erbersdobler, Andreas; Hakenberg, Oliver W; Koch, Stefan; May, Matthias

2012-03-01

To evaluate the role of p53, p21 and cyclin D1 expression in patients with penile cancer (PC). Paraffin-embedded tissues from PC specimens from six pathology departments were subjected to a central histopathological review performed by one pathologist. The tissue microarray technique was used for immunostaining which was evaluated by two independent pathologists and correlated with cancer-specific survival (CSS). κ-statistics were used to assess interobserver variability. Uni- and multivariable Cox proportional hazards analysis was applied to assess the independent effects of several prognostic factors on CSS over a median of 32 months (IQR 6-66 months). Specimens and clinical data from 110 men treated surgically for primary PC were collected. p53 staining was positive in 30 and negative in 62 specimens. κ-statistics showed substantial interobserver reproducibility of p53 staining evaluation (κ=0.73; p<0.001). The 5-year CSS rate for the entire study cohort was 74%. Five-year CSS was 84% in p53-negative and 51% in p53-positive PC patients (p=0.003). Multivariable analysis showed p53 (HR=3.20; p=0.041) and pT-stage (HR=4.29; p<0.001) as independent significant prognostic factors for CSS. Cyclin D1 and p21 expression were not correlated with survival. However, incorporating p21 into a multivariable Cox model did contribute to improved model quality for predicting CSS. In patients with PC, the expression of p53 in the primary tumour specimen can be reproducibly assessed and is negatively associated with cancer specific survival.

Sperm associated antigen 9 (SPAG9) a promising therapeutic target of ovarian carcinoma.

PubMed

Jagadish, Nirmala; Fatima, Rukhsar; Sharma, Aditi; Devi, Sonika; Suri, Vitusha; Kumar, Vikash; Suri, Anil

2018-05-01

SPAG9 is a novel tumor associated antigen, expressed in variety of malignancies. However, its role in ovarian cancer remains unexplored. SPAG9 expression was validated in ovarian cancer cells by real time PCR and Western blot. SPAG9 involvement in cell cycle, DNA damage, apoptosis, paclitaxel sensitivity and epithelial- mesenchymal transition (EMT) was investigated employing RNA interference approach. Combinatorial effect of SPAG9 ablation and paclitaxel treatment was evaluated in in vitro. Quantitative PCR and Western blot analysis revealed SPAG9 expression in A10, SKOV-3 and Caov3 compared to normal ovarian epithelial cells. SPAG9 ablation resulted in reduced cellular proliferation, colony forming ability and enhanced cytotoxicity of chemotherapeutic agent paclitaxel. Effect of ablation of SPAG9 on cell cycle revealed S phase arrest and showed decreased expression of CDK1, CDK2, CDK4, CDK6, cyclin B1, cyclin D1, cyclin E and increased expression of tumor suppressor p21. Ablation of SPAG9 also resulted in increased apoptosis with increased expression of various pro- apoptotic molecules including BAD, BID, PUMA, caspase 3, caspase 7, caspase 8 and cytochrome C. Decreased expression of mesenchymal markers and increased expression of epithelial markers was found in SPAG9 ablated cells. Combinatorial effect of SPAG9 ablation and paclitaxel treatment was evaluated in in vitro assays which showed that ablation of SPAG9 resulted in increased paclitaxel sensitivity and caused enhanced cell death. In vivo ovarian cancer xenograft studies showed that ablation of SPAG9 resulted in significant reduction in tumor growth. Present study revealed therapeutic potential of SPAG9 in ovarian cancer.

[Effects of fasudil on bleomycin-induced pulmonary fibrosis in mice and on the biological behaviors in NIH3T3 mouse fibroblast cell line].

PubMed

Jiang, Chunguo; Huang, Hui; Liu, Jia; Wang, Yanxun; Zhao, Yuyue; Xu, Zuojun

2014-09-01

To determine the beneficial effects and mechanisms of fasudil, a selective ROCK inhibitor, on bleomycin-induced pulmonary fibrosis in mice and to determine the effects and mechanisms of fasudil on the biological behaviors in NIH3T3 mouse fibroblast cell line. The BPF model was induced by a single dosage of 2.5 mg/kg bleomycin intratracheal injection in mice and fasudil intraperitoneal injection was given to the mice. The fibrosis degree was determined pathologically by using the Ashcroft scoring method and biochemically by hydroxyproline assay in lung tissue. NIH3T3 mouse fibroblast cell line was cultured in vitro and fasudil was given to the cell. The proliferation activity in NIH3T3 cells were detected by MTT assay and flat colony forming experiment. The migration activity in NIH3T3 cells were detected by scratch test and transwell chamber experiment. The expression of CyclinD1, MMP2 and TIMP1 mRNA in NIH3T3 cells was detected by RT-PCR. The expression of CyclinD1, MMP2 and TIMP1 protein and the level of MYPT1 phosphorylation in NIH3T3 cells was detected by Western blot. Compare to the mice administrated by bleomycin, the Ashcroft score and hydroxyproline content were significantly decreased in the mice administered fasudil. Administration of fasudil can reduce the ability of proliferation and migration in a dose-dependent manner in NIH3T3 cells. The effect of fasudil was possibly related to increase the production of TIMP1 and decrease the production of CyclinD1 and MMP2. Administration of fasudil can attenuate pulmonary fibrosis both in vivo and in vitro. These findings suggest that fasudil may be a potential therapeutic candidate for the treatment of pulmonary fibrosis.

Differential expression of Cyclin D1 in keratin-producing odontogenic cysts

PubMed Central

Vera-Sirera, Beatriz; Forner-Navarro, Leopoldo

2015-01-01

Objetives: The aim of the present study was to analyze the expression levels of Cyclin D1 (CCD1), a nuclear protein that plays a crucial role in cell cycle progression, in a series of keratin-producing odontogenic cysts. Study Design: A total of 58 keratin-producing odontogenic cysts, diagnosed over ten years and classified according to the WHO 2005 criteria, were immunohistochemically analyzed in terms of CCD1 expression, which was quantified in the basal, suprabasal and intermediate/superficial epithelial compartments. The extent of immunostaining was measured as a proportion of total epithelial thickness. Quantified immunohistochemical data were correlated with clinicopathological features and clinical recurrence. Results: Keratin-producing odontogenic cysts were classified as 6 syndromic keratocystic odontogenic tumors (S-KCOT), 40 sporadic or non-syndromic KCOT (NS-KCOT) and 12 orthokeratinized odontogenic cysts (OOC). Immunohistochemically, CCD1 staining was evident predominantly in the parabasal region of all cystic lesions, but among-lesion differences were apparent, showing a clear expansion of parabasal compartment especially in the S-KCOT, followed to a lesser extent in the NS-KCOT, and being much more reduced in the OOC, which had the greatest average epithelial thickness. Conclusions: The differential expression of CCD1 noted in the present study suggests that dysregulation of cell cycle progression from G1 to the S phase contributes to the different aggressiveness of these lesions. However, CCD1 expression levels did not predict NS-KCOT recurrence, which is likely influenced by factors unrelated to lesion biology. Key words:Keratin-producing odontogenic cyst, keratocyst, keratocystic odontogenic tumor, nevoid basal cell carcinoma syndrome, orthokeratinized odontogenic cyst, cyclin D1, immunohistochemistry. PMID:25475773

Markers of potential malignancy in chronic hyperplastic candidiasis.

PubMed

Darling, Mark R; McCord, Christina; Jackson-Boeters, Linda; Copete, Maria

2012-08-01

To examine the presence of markers associated with malignancy, including p53, p21 cyclin-dependent kinase inhibitor 1A, murine double minutes-2, and others, in chronic hyperplastic candidiasis. Immunohistochemical methods were used to examine the expression of p53, murine double minutes-2, p21 cyclin-dependent kinase inhibitor 1A, metallothionein, and proliferating cell nuclear antigen in 42 chronic hyperplastic candidiasis lesions and 11 non-infected control tissues. Terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling was used to examine apoptosis, which was correlated with p53 expression. These markers were measured in lesions of chronic hyperplastic candidiasis that did not show any epithelial dysplasia or histological signs of malignancy. p53 scores were higher in chronic hyperplastic candidiasis than in controls (P = 0.0046). Murine double-minutes 2 levels were not elevated. p21 cyclin-dependent kinase inhibitor 1A was increased in parabasal (P < 0.0001) and basal epithelial cells. Chronic hyperplastic candidiasis lesions showed a similar basal/parabasal metallothionein staining pattern to that seen in normal squamous epithelium. Proliferating cell nuclear antigen was increased (P = 0.0007), as was apoptosis (P = 0.0033). Increased p53 in oral chronic hyperplastic candidiasis suggests an increased potential for malignant change in the epithelium, above that of normal tissues. Further functional investigation is required, as well as clinical follow-up studies. © 2012 Blackwell Publishing Asia Pty Ltd.

Saponins from soy bean and mung bean inhibit the antigen specific activation of helper T cells by blocking cell cycle progression.

PubMed

Lee, Suk Jun; Bae, Joonbeom; Kim, Sunhee; Jeong, Seonah; Choi, Chang-Yong; Choi, Sang-Pil; Kim, Hyun-Sook; Jung, Woon-Won; Imm, Jee-Young; Kim, Sae Hun; Chun, Taehoon

2013-02-01

Treatment of helper T (Th) cells with saponins from soy bean and mung bean prevented their activation by inhibiting cell proliferation and cytokine secretion. However, the saponins did not affect the expression of major histocompatibility complex class II (A(b)) and co-stimulatory molecule (CD86) on professional antigen-presenting cells. Instead, the saponins directly inhibited Th cell proliferation by blocking the G(1) to S phase cell cycle transition. Moreover, blocking of the cell cycle by the saponins was achieved by decreased expression of cyclin D1 and cyclin E, and constitutive expression of p27(KIP1). Saponins also increased stability of p27(KIP1) in Th cells after antigenic stimulation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Ru-Ming; Sun, Ren-Gang; Zhang, Ling-Tao

This study investigated the pro-proliferative effect of hyaluronic acid (HA) on human amniotic mesenchymal stem cells (hAMSCs) and the underlying mechanisms. Treatment with HA increased cell population growth in a dose- and time-dependent manner. Analyses by flow cytometry and immunocytochemistry revealed that HA did not change the cytophenotypes of hAMSCs. Additionally, the osteogenic, chondrogenic, and adipogenic differentiation capabilities of these hAMSCs were retained after HA treatment. Moreover, HA increased the mRNA expressions of wnt1, wnt3a, wnt8a, cyclin D1, Ki-67, and β-catenin as well as the protein level of β-catenin and cyclin D1 in hAMSCs; and the nuclear localization of β-cateninmore » was also enhanced. Furthermore, the pro-proliferative effect of HA and up-regulated expression of Wnt/β-catenin pathway-associated proteins - wnt3a, β-catenin and cyclin D1 in hAMSCs were significantly inhibited upon pre-treatment with Wnt-C59, an inhibitor of the Wnt/β-catenin pathway. These results suggest that HA may positively regulate hAMSCs proliferation through regulation of the Wnt/β-catenin signaling pathway. - Highlights: • Hyaluronic acid (HA) could promote the proliferation of hAMSCs. • HA treatment dose not affect the pluripotency of hAMSCs. • HA increases hAMSCs proliferation through activation of Wnt/β-catenin signaling.« less

Up-Regulation of Long Noncoding RNA SRA Promotes Cell Growth, Inhibits Cell Apoptosis, and Induces Secretion of Estradiol and Progesterone in Ovarian Granular Cells of Mice.

PubMed

Li, Yan; Wang, Haixu; Zhou, Dangxia; Shuang, Ting; Zhao, Haibo; Chen, Biliang

2018-04-20

BACKGROUND Increasing evidence indicates that long noncoding RNAs (LncRNAs) play a key role in multiple pathological processes. It has been shown that LncRNA steroid receptor RNA activator (SRA) is elevated in peripheral blood of patients with polycystic ovary syndrome (PCOS). The aim of this study was to assess the effect of elevated LncRNA SRA on ovarian granular cells of mice in vitro. MATERIAL AND METHODS We firstly isolated granular cells from mouse ovaries and over-expressed the LncRNA SRA by means of lentiviral transfection in this cell line. Then, we assessed the effects of LncRNA SRA on granular cells through real-time PCR, CCK-8 assay, flow cytometry, Hoechst staining, and Western blot assay. RESULTS We demonstrated that elevated LncRNA SRA stimulated cell growth, changed distribution of cell cycle phases with increase of Cyclin B, Cyclin E, and Cyclin D1, and inhibited cell apoptosis with up-regulation of bcl2 and down-regulation of bax, cleaved-caspase 3, and cleaved-PARP. Moreover, the contents of estradiol (E2) and progesterone (PG) and expressions of their key enzymes (CYP19A1 and CYP11A1) were up-regulated following over-expression of LncRNA SRA. CONCLUSIONS Taken together, our results indicate that abnormal LncRNA SRA may be a risk factor for evoking PCOS.

Global analysis of the ovarian microRNA transcriptome: implication for miR-2 and miR-133 regulation of oocyte meiosis in the Chinese mitten crab, Eriocheir sinensis (Crustacea:Decapoda).

PubMed

Song, Ya-Nan; Shi, Li-Li; Liu, Zhi-Qiang; Qiu, Gao-Feng

2014-07-01

MicroRNAs (miRNAs) are small non-coding RNA molecules that downregulate gene expression by base pairing to the 3'-untranslated region (UTR) of target messenger RNAs (mRNAs). Up to now, rare information for the miRNAs is available in decapod crustaceans. Our previous studies showed that many miRNA-binding sites are present in the 3'-UTR of the cyclin B in the Chinese mitten crab Eriocheir sinensis, suggesting that the translation or post-transcription of the crab cyclin B might be regulated by miRNAs during meiosis of oocyte. To identify ovarian miRNAs in the mitten crab, ovarian small RNAs were subjected to high-throughput sequencing using an Illumina Genome Analyzer. Of 14,631,328 reads, 55 known miRNAs representing 44 miRNA families were identified and 136 novel miRNA candidates were predicted. The 5' seed sequences of four miRNAs, miR-2, miR-7, miR-79 and miR-133, were revealed to complementary to miRNA binding sites in 3'-UTR of the cyclin B. Quantitative real time PCR analysis showed that miR-2 and miR-133 are much more abundant in the first metaphase (MI) of meiosis than in germinal vesicle (GV) stage. But their increasing expressions are independent of induction of gonadotropin-releasing hormone (GnRH). Further expression analysis using double-luciferase reporter genes assay showed that miR-2 and miR-133 can downregulate the 3'-UTRs of the crab cyclin B gene, indicating that they could inhibit the translation of the cyclin B. Western blot analysis confirmed that cyclin B protein is completely disappeared in fertilized egg at the metaphase-anaphase transition of meiosis I, suggesting that miR-2 and miR-133 could function in destruction of cyclin B near the end of MI. A high number of miRNAs have been identified from the crab ovarian small RNA transcriptom for the first time. miR-2 and miR-133 exhibit differential expression during the meiotic maturation of the oocytes and have activity in regulating the 3'-UTR of the crab cyclin B gene. This result is inconsistent with recent finding that miRNA activity is globally suppressed in mouse oocytes.

Functional Variants at the 11q13 Risk Locus for Breast Cancer Regulate Cyclin D1 Expression through Long-Range Enhancers

PubMed Central

French, Juliet D.; Ghoussaini, Maya; Edwards, Stacey L.; Meyer, Kerstin B.; Michailidou, Kyriaki; Ahmed, Shahana; Khan, Sofia; Maranian, Mel J.; O’Reilly, Martin; Hillman, Kristine M.; Betts, Joshua A.; Carroll, Thomas; Bailey, Peter J.; Dicks, Ed; Beesley, Jonathan; Tyrer, Jonathan; Maia, Ana-Teresa; Beck, Andrew; Knoblauch, Nicholas W.; Chen, Constance; Kraft, Peter; Barnes, Daniel; González-Neira, Anna; Alonso, M. Rosario; Herrero, Daniel; Tessier, Daniel C.; Vincent, Daniel; Bacot, Francois; Luccarini, Craig; Baynes, Caroline; Conroy, Don; Dennis, Joe; Bolla, Manjeet K.; Wang, Qin; Hopper, John L.; Southey, Melissa C.; Schmidt, Marjanka K.; Broeks, Annegien; Verhoef, Senno; Cornelissen, Sten; Muir, Kenneth; Lophatananon, Artitaya; Stewart-Brown, Sarah; Siriwanarangsan, Pornthep; Fasching, Peter A.; Loehberg, Christian R.; Ekici, Arif B.; Beckmann, Matthias W.; Peto, Julian; dos Santos Silva, Isabel; Johnson, Nichola; Aitken, Zoe; Sawyer, Elinor J.; Tomlinson, Ian; Kerin, Michael J.; Miller, Nicola; Marme, Frederik; Schneeweiss, Andreas; Sohn, Christof; Burwinkel, Barbara; Guénel, Pascal; Truong, Thérèse; Laurent-Puig, Pierre; Menegaux, Florence; Bojesen, Stig E.; Nordestgaard, Børge G.; Nielsen, Sune F.; Flyger, Henrik; Milne, Roger L.; Zamora, M. Pilar; Arias Perez, Jose Ignacio; Benitez, Javier; Anton-Culver, Hoda; Brenner, Hermann; Müller, Heiko; Arndt, Volker; Stegmaier, Christa; Meindl, Alfons; Lichtner, Peter; Schmutzler, Rita K.; Engel, Christoph; Brauch, Hiltrud; Hamann, Ute; Justenhoven, Christina; Aaltonen, Kirsimari; Heikkilä, Päivi; Aittomäki, Kristiina; Blomqvist, Carl; Matsuo, Keitaro; Ito, Hidemi; Iwata, Hiroji; Sueta, Aiko; Bogdanova, Natalia V.; Antonenkova, Natalia N.; Dörk, Thilo; Lindblom, Annika; Margolin, Sara; Mannermaa, Arto; Kataja, Vesa; Kosma, Veli-Matti; Hartikainen, Jaana M.; Wu, Anna H.; Tseng, Chiu-chen; Van Den Berg, David; Stram, Daniel O.; Lambrechts, Diether; Peeters, Stephanie; Smeets, Ann; Floris, Giuseppe; Chang-Claude, Jenny; Rudolph, Anja; Nickels, Stefan; Flesch-Janys, Dieter; Radice, Paolo; Peterlongo, Paolo; Bonanni, Bernardo; Sardella, Domenico; Couch, Fergus J.; Wang, Xianshu; Pankratz, Vernon S.; Lee, Adam; Giles, Graham G.; Severi, Gianluca; Baglietto, Laura; Haiman, Christopher A.; Henderson, Brian E.; Schumacher, Fredrick; Le Marchand, Loic; Simard, Jacques; Goldberg, Mark S.; Labrèche, France; Dumont, Martine; Teo, Soo Hwang; Yip, Cheng Har; Ng, Char-Hong; Vithana, Eranga Nishanthie; Kristensen, Vessela; Zheng, Wei; Deming-Halverson, Sandra; Shrubsole, Martha; Long, Jirong; Winqvist, Robert; Pylkäs, Katri; Jukkola-Vuorinen, Arja; Grip, Mervi; Andrulis, Irene L.; Knight, Julia A.; Glendon, Gord; Mulligan, Anna Marie; Devilee, Peter; Seynaeve, Caroline; García-Closas, Montserrat; Figueroa, Jonine; Chanock, Stephen J.; Lissowska, Jolanta; Czene, Kamila; Klevebring, Daniel; Schoof, Nils; Hooning, Maartje J.; Martens, John W.M.; Collée, J. Margriet; Tilanus-Linthorst, Madeleine; Hall, Per; Li, Jingmei; Liu, Jianjun; Humphreys, Keith; Shu, Xiao-Ou; Lu, Wei; Gao, Yu-Tang; Cai, Hui; Cox, Angela; Balasubramanian, Sabapathy P.; Blot, William; Signorello, Lisa B.; Cai, Qiuyin; Pharoah, Paul D.P.; Healey, Catherine S.; Shah, Mitul; Pooley, Karen A.; Kang, Daehee; Yoo, Keun-Young; Noh, Dong-Young; Hartman, Mikael; Miao, Hui; Sng, Jen-Hwei; Sim, Xueling; Jakubowska, Anna; Lubinski, Jan; Jaworska-Bieniek, Katarzyna; Durda, Katarzyna; Sangrajrang, Suleeporn; Gaborieau, Valerie; McKay, James; Toland, Amanda E.; Ambrosone, Christine B.; Yannoukakos, Drakoulis; Godwin, Andrew K.; Shen, Chen-Yang; Hsiung, Chia-Ni; Wu, Pei-Ei; Chen, Shou-Tung; Swerdlow, Anthony; Ashworth, Alan; Orr, Nick; Schoemaker, Minouk J.; Ponder, Bruce A.J.; Nevanlinna, Heli; Brown, Melissa A.; Chenevix-Trench, Georgia; Easton, Douglas F.; Dunning, Alison M.

2013-01-01

Analysis of 4,405 variants in 89,050 European subjects from 41 case-control studies identified three independent association signals for estrogen-receptor-positive tumors at 11q13. The strongest signal maps to a transcriptional enhancer element in which the G allele of the best candidate causative variant rs554219 increases risk of breast cancer, reduces both binding of ELK4 transcription factor and luciferase activity in reporter assays, and may be associated with low cyclin D1 protein levels in tumors. Another candidate variant, rs78540526, lies in the same enhancer element. Risk association signal 2, rs75915166, creates a GATA3 binding site within a silencer element. Chromatin conformation studies demonstrate that these enhancer and silencer elements interact with each other and with their likely target gene, CCND1. PMID:23540573

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, William Ka Kei; Lee, Chung Wa; Cho, Chi Hin

Mammalian target of rapamycin complex 1 (mTORC1) is dysregulated in gastric cancer. The biologic function of mTORC1 in gastric carcinogenesis is unclear. Here, we demonstrate that disruption of mTORC1 function by RNA interference-mediated downregulation of raptor substantially inhibited gastric cancer cell proliferation through induction of G{sub 0}/G{sub 1}-phase cell cycle arrest. The anti-proliferative effect was accompanied by concomitant downregulation of activator protein-1 and upregulation of Smad2/3 transcriptional activities. In addition, the expression of cyclin D{sub 3} and p21{sup Waf1}, which stabilizes cyclin D/cdk4 complex for G{sub 1}-S transition, was reduced by raptor knockdown. In conclusion, disruption of mTORC1 inhibits gastricmore » cancer cell proliferation through multiple pathways. This discovery may have an implication in the application of mTORC1-directed therapy for the treatment of gastric cancer.« less

Nuclear receptor TLX regulates cell cycle progression in neural stem cells of the developing brain.

PubMed

Li, Wenwu; Sun, Guoqiang; Yang, Su; Qu, Qiuhao; Nakashima, Kinichi; Shi, Yanhong

2008-01-01

TLX is an orphan nuclear receptor that is expressed exclusively in vertebrate forebrains. Although TLX is known to be expressed in embryonic brains, the mechanism by which it influences neural development remains largely unknown. We show here that TLX is expressed specifically in periventricular neural stem cells in embryonic brains. Significant thinning of neocortex was observed in embryonic d 14.5 TLX-null brains with reduced nestin labeling and decreased cell proliferation in the germinal zone. Cell cycle analysis revealed both prolonged cell cycles and increased cell cycle exit in TLX-null embryonic brains. Increased expression of a cyclin-dependent kinase inhibitor p21 and decreased expression of cyclin D1 provide a molecular basis for the deficiency of cell cycle progression in embryonic brains of TLX-null mice. Furthermore, transient knockdown of TLX by in utero electroporation led to precocious cell cycle exit and differentiation of neural stem cells followed by outward migration. Together these results indicate that TLX plays an important role in neural development by regulating cell cycle progression and exit of neural stem cells in the developing brain.

Nuclear Receptor TLX Regulates Cell Cycle Progression in Neural Stem Cells of the Developing Brain

PubMed Central

Li, Wenwu; Sun, Guoqiang; Yang, Su; Qu, Qiuhao; Nakashima, Kinichi; Shi, Yanhong

2008-01-01

TLX is an orphan nuclear receptor that is expressed exclusively in vertebrate forebrains. Although TLX is known to be expressed in embryonic brains, the mechanism by which it influences neural development remains largely unknown. We show here that TLX is expressed specifically in periventricular neural stem cells in embryonic brains. Significant thinning of neocortex was observed in embryonic d 14.5 TLX-null brains with reduced nestin labeling and decreased cell proliferation in the germinal zone. Cell cycle analysis revealed both prolonged cell cycles and increased cell cycle exit in TLX-null embryonic brains. Increased expression of a cyclin-dependent kinase inhibitor p21 and decreased expression of cyclin D1 provide a molecular basis for the deficiency of cell cycle progression in embryonic brains of TLX-null mice. Furthermore, transient knockdown of TLX by in utero electroporation led to precocious cell cycle exit and differentiation of neural stem cells followed by outward migration. Together these results indicate that TLX plays an important role in neural development by regulating cell cycle progression and exit of neural stem cells in the developing brain. PMID:17901127

LIM Domain Only 2 Regulates Endothelial Proliferation, Angiogenesis, and Tissue Regeneration.

PubMed

Meng, Shu; Matrone, Gianfranco; Lv, Jie; Chen, Kaifu; Wong, Wing Tak; Cooke, John P

2016-10-06

LIM domain only 2 (LMO2, human gene) is a key transcription factor that regulates hematopoiesis and vascular development. However, its role in adult endothelial function has been incompletely characterized. In vitro loss- and gain-of-function studies on LMO2 were performed in human umbilical vein endothelial cells with lentiviral overexpression or short hairpin RNA knockdown (KD) of LMO2, respectively. LMO2 KD significantly impaired endothelial proliferation. LMO2 controls endothelial G1/S transition through transcriptional regulation of cyclin-dependent kinase 2 and 4 as determined by reverse transcription polymerase chain reaction (PCR), western blot, and chromatin immunoprecipitation, and also influences the expression of Cyclin D1 and Cyclin A1. LMO2 KD also impaired angiogenesis by reducing transforming growth factor-β (TGF-β) expression, whereas supplementation of exogenous TGF-β restored defective network formation in LMO2 KD human umbilical vein endothelial cells. In a zebrafish model of caudal fin regeneration, RT-PCR revealed that the lmo2 (zebrafish gene) gene was upregulated at day 5 postresection. The KD of lmo2 by vivo-morpholino injections in adult Tg(fli1:egfp) y1 zebrafish reduced 5-bromo-2'-deoxyuridine incorporation in endothelial cells, impaired neoangiogenesis in the resected caudal fin, and substantially delayed fin regeneration. The transcriptional factor LMO2 regulates endothelial proliferation and angiogenesis in vitro. Furthermore, LMO2 is required for angiogenesis and tissue healing in vivo. Thus, LMO2 is a critical determinant of vascular and tissue regeneration. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

High density lipoprotein promotes proliferation of adipose-derived stem cells via S1P1 receptor and Akt, ERK1/2 signal pathways.

PubMed

Shen, Haitao; Zhou, Enchen; Wei, Xiujing; Fu, Zhiwei; Niu, Chenguang; Li, Yang; Pan, Bing; Mathew, Anna V; Wang, Xu; Pennathur, Subramaniam; Zheng, Lemin; Wang, Yongyu

2015-05-15

Adipose-derived stem cells (ADSC) are non-hematopoietic mesenchymal stem cells that have shown great promise in their ability to differentiate into multiple cell lineages. Their ubiquitous nature and the ease of harvesting have attracted the attention of many researchers, and they pose as an ideal candidate for applications in regenerative medicine. Several reports have demonstrated that transplanting ADSC can promote repair of injured tissue and angiogenesis in animal models. Survival of these cells after transplant remains a key limiting factor for the success of ADSC transplantation. Circulating factors like High Density Lipoprotein (HDL) has been known to promote survival of other stems cells like bone marrow derived stem cells and endothelial progenitor cells, both by proliferation and by inhibiting cell apoptosis. The effect of HDL on transplanted adipose-derived stem cells in vivo is largely unknown. This study focused on exploring the effects of plasma HDL on ADSC and delineating the mechanisms involved in their proliferation after entering the bloodstream. Using the MTT and BrdU assays, we tested the effects of HDL on ADSC proliferation. We probed the downstream intracellular Akt and ERK1/2 signaling pathways and expression of cyclin proteins in ADSC using western blot. Our study found that HDL promotes proliferation of ADSC, by binding to sphingosine-1- phosphate receptor-1(S1P1) on the cell membrane. This interaction led to activation of intracellular Akt and ERK1/2 signaling pathways, resulting in increased expression of cyclin D1 and cyclin E, and simultaneous reduction in expression of cyclin-dependent kinase inhibitors p21 and p27, therefore promoting cell cycle progression and cell proliferation. These studies raise the possibility that HDL may be a physiologic regulator of stem cells and increasing HDL concentrations may be valuable strategy to promote ADSC transplantation.

The Potential Role of As-sumo-1 in the Embryonic Diapause Process and Early Embryo Development of Artemia sinica

PubMed Central

Chu, Bing; Yao, Feng; Cheng, Cheng; Wu, Yang; Mei, Yanli; Li, Xuejie; Liu, Yan; Wang, Peisheng; Hou, Lin; Zou, Xiangyang

2014-01-01

During embryonic development of Artemia sinica, environmental stresses induce the embryo diapause phenomenon, required to resist apoptosis and regulate cell cycle activity. The small ubiquitin-related modifier-1 (SUMO), a reversible post-translational protein modifier, plays an important role in embryo development. SUMO regulates multiple cellular processes, including development and other biological processes. The molecular mechanism of diapause, diapause termination and the role of As-sumo-1 in this processes and in early embryo development of Artemia sinica still remains unknown. In this study, the complete cDNA sequences of the sumo-1 homolog, sumo ligase homolog, caspase-1 homolog and cyclin B homolog from Artemia sinica were cloned. The mRNA expression patterns of As-sumo-1, sumo ligase, caspase-1, cyclin B and the location of As-sumo-1 were investigated. SUMO-1, p53, Mdm2, Caspase-1, Cyclin B and Cyclin E proteins were analyzed during different developmental stages of the embryo of A. sinica. Small interfering RNA (siRNA) was used to verify the function of sumo-1 in A. sinica. The full-length cDNA of As-sumo-1 was 476 bp, encoding a 92 amino acid protein. The As-caspases-1 cDNA was 966 bp, encoding a 245 amino-acid protein. The As-sumo ligase cDNA was 1556 bp encoding, a 343 amino acid protein, and the cyclin B cDNA was 739 bp, encoding a 133 amino acid protein. The expressions of As-sumo-1, As-caspase-1 and As-cyclin B were highest at the 10 h stage of embryonic development, and As-sumo ligase showed its highest expression at 0 h. The expression of As-SUMO-1 showed no tissue or organ specificity. Western blotting showed high expression of As-SUMO-1, p53, Mdm2, Caspase-1, Cyclin B and Cyclin E at the 10 h stage. The siRNA caused abnormal development of the embryo, with increased malformation and mortality. As-SUMO-1 is a crucial regulation and modification protein resumption of embryonic diapause and early embryo development of A. sinica. PMID:24404204

Prognostic value of cell cycle regulatory proteins in muscle-infiltrating bladder cancer.

PubMed

Galmozzi, Fabia; Rubagotti, Alessandra; Romagnoli, Andrea; Carmignani, Giorgio; Perdelli, Luisa; Gatteschi, Beatrice; Boccardo, Francesco

2006-12-01

The aims of this study were to investigate the expression levels of proteins involved in cell cycle regulation in specimens of bladder cancer and to correlate them with the clinicopathological characteristics, proliferative activity and survival. Eighty-two specimens obtained from patients affected by muscle-invasive bladder cancer were evaluated immunohistochemically for p53, p21 and cyclin D1 expression, as well as for the tumour proliferation index, Ki-67. The statistical analysis included Kaplan-Meier curves with log-rank test and Cox proportional hazards models. In univariate analyses, low Ki-67 proliferation index (P = 0.045) and negative p21 immunoreactivity (P = 0.04) were associated to patient's overall survival (OS), but in multivariate models p21 did not reach statistical significance. When the combinations of the variables were assessed in two separate multivariate models that included tumour stage, grading, lymph node status, vascular invasion and perineural invasion, the combined variables p21/Ki-67 or p21/cyclin D1 expression were independent predictors for OS; in particular, patients with positive p21/high Ki-67 (P = 0.015) or positive p21/negative cyclin D1 (P = 0.04) showed the worst survival outcome. Important alterations in the cell cycle regulatory pathways occur in muscle-invasive bladder cancer and the combined use of cell cycle regulators appears to provide significant prognostic information that could be used to select the patients most suitable for multimodal therapeutic approaches.

American cranberry (Vaccinium macrocarpon) extract affects human prostate cancer cell growth via cell cycle arrest by modulating expression of cell cycle regulators.

PubMed

Déziel, Bob; MacPhee, James; Patel, Kunal; Catalli, Adriana; Kulka, Marianna; Neto, Catherine; Gottschall-Pass, Katherine; Hurta, Robert

2012-05-01

Prostate cancer is one of the most common cancers in the world, and its prevalence is expected to increase appreciably in the coming decades. As such, more research is necessary to understand the etiology, progression and possible preventative measures to delay or to stop the development of this disease. Recently, there has been interest in examining the effects of whole extracts from commonly harvested crops on the behaviour and progression of cancer. Here, we describe the effects of whole cranberry extract (WCE) on the behaviour of DU145 human prostate cancer cells in vitro. Following treatment of DU145 human prostate cancer cells with 10, 25 and 50 μg ml⁻¹ of WCE, respectively for 6 h, WCE significantly decreased the cellular viability of DU145 cells. WCE also decreased the proportion of cells in the G2-M phase of the cell cycle and increased the proportion of cells in the G1 phase of the cell cycle following treatment of cells with 25 and 50 μg ml⁻¹ treatment of WCE for 6 h. These alterations in cell cycle were associated with changes in cell cycle regulatory proteins and other cell cycle associated proteins. WCE decreased the expression of CDK4, cyclin A, cyclin B1, cyclin D1 and cyclin E, and increased the expression of p27. Changes in p16(INK4a) and pRBp107 protein expression levels also were evident, however, the changes noted in p16(INK4a) and pRBp107 protein expression levels were not statistically significant. These findings demonstrate that phytochemical extracts from the American cranberry (Vaccinium macrocarpon) can affect the behaviour of human prostate cancer cells in vitro and further support the potential health benefits associated with cranberries.

1-(2-Hydroxy-5-methylphenyl)-3-phenyl-1,3-propanedione Induces G1 Cell Cycle Arrest and Autophagy in HeLa Cervical Cancer Cells.

PubMed

Tsai, Jie-Heng; Hsu, Li-Sung; Huang, Hsiu-Chen; Lin, Chih-Li; Pan, Min-Hsiung; Hong, Hui-Mei; Chen, Wei-Jen

2016-08-05

The natural agent, 1-(2-hydroxy-5-methylphenyl)-3-phenyl-1,3-propanedione (HMDB), has been reported to have growth inhibitory effects on several human cancer cells. However, the role of HMDB in cervical cancer remains unclear. Herein, we found that HMDB dose- and time-dependently inhibited growth of HeLa cervical cancer cells, accompanied with G1 cell cycle arrest. HMDB decreased protein expression of cyclins D1/D3/E and cyclin-dependent kinases (CDKs) 2/4/6 and reciprocally increased mRNA and protein levels of CDK inhibitors (p15, p16, p21, and p27), thereby leading to the accumulation of hypophosphorylated retinoblastoma (Rb) protein. HMDB also triggered the accumulation of acidic vesicles and formation of microtubule-associated protein-light chain 3 (LC3), followed by increased expression of LC3 and Beclin-1 and decreased expression of p62, suggesting that HMDB triggered autophagy in HeLa cells. Meanwhile, suppression of the expression of survivin and Bcl-2 implied that HMDB-induced autophagy is tightly linked to apoptosis. Exploring the action mechanism, HMDB induced autophagy via the modulation of AMP-activated protein kinase (AMPK) and mTOR signaling pathway rather than the class III phosphatidylinositol 3-kinase pathway. These results suggest that HMDB inhibits HeLa cell growth by eliciting a G1 arrest through modulation of G1 cell cycle regulators and by concomitantly inducing autophagy through the mediation of AMPK-mTOR and Akt-mTOR pathways, and may be a promising antitumor agent against cervical cancer.

Cyclin D1 in the Liver: Role of Noncanonical Signaling in Liver Steatosis and Hormone Regulation

PubMed Central

Núñez, Kelley G.; Gonzalez-Rosario, Janet; Thevenot, Paul T.; Cohen, Ari J.

2017-01-01

Background: Cyclin D1 is an important protein for cell cycle progression; however, functions independent of the cell cycle have been described in the liver. Cyclin D1 is also involved in DNA repair, is overexpressed in many cancers, and functions as a proto-oncogene. The lesser-known roles of Cyclin D1, specifically in hepatocytes, impact liver steatosis and hormone regulation in the liver. Methods: A comprehensive search of PubMed was conducted using the keywords Cyclin D1, steatosis, lipogenesis, and liver transplantation. In this article, we review the results from this literature search, with a focus on the role of Cyclin D1 in hepatic lipogenesis and gluconeogenesis, as well as the impact and function of this protein in hepatic steatosis. Results: Cyclin D1 represses carbohydrate response element binding protein (ChREBP) and results in a decrease in transcription of fatty acid synthase (FAS) and acetyl-coenzyme A carboxylase (ACC). Cyclin D1 also inhibits peroxisome proliferator-activated receptor gamma (PPARγ) which is involved in hepatic lipogenesis. Cyclin D1 inhibits both hepatocyte nuclear factor 4 alpha (HNF4α) and peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1α) and represses transcription of lipogenic genes FAS and liver-type pyruvate kinase (Pklr), along with the gluconeogenic genes phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase). Conclusion: Cyclin D1 represses multiple proteins involved in both lipogenesis and gluconeogenesis in the liver. Targeting Cyclin D1 to decrease hepatic steatosis in patients with nonalcoholic fatty liver disease or alcoholic fatty liver disease may help improve patient health and the quality of the donor liver pool. PMID:28331449

Evaluation of NF-kappaB Signaling in T Cells

DTIC Science & Technology

2009-01-01

ranging from myelomas (46) to breast cancer (47) to esophageal cancer (48), to name a few. NF-κB activation is also implicated in several leukemias and...nuclear factor-kappaB/Rel expression and the pathogenesis of breast cancer . J Clin Invest 100:2952-2960. 48. Abdel-Latif, M. M., J. O’Riordan, H. J...42), cyclin D1 (43), and cyclin E (44, 45). Furthermore, NF-κB activity has been linked to the proliferation of various types of cancer cells

Enterolactone induces G1-phase cell cycle arrest in non-small cell lung cancer cells by down-regulating cyclins and cyclin-dependent kinases

PubMed Central

Chikara, Shireen; Lindsey, Kaitlin; Dhillon, Harsharan; Mamidi, Sujan; Kittilson, Jeffrey; Christofidou-Solomidou, Melpo; Reindl, Katie M.

2017-01-01

Flaxseed is a rich source of the plant lignan secoisolariciresinol diglucoside (SDG) which is metabolized into mammalian lignans enterodiol (ED) and enterolactone (EL) in the digestive tract. The anti-cancer properties of these lignans have been demonstrated for various cancer types, but have not been studied for lung cancer. In this study we investigated the anti-cancer effects of EL for several non-small cell lung cancer (NSCLC) cell lines of various genetic backgrounds. EL inhibited the growth of A549, H441, and H520 lung cancer cells in concentration- and time-dependent manners. The anti-proliferative effects of EL for lung cancer cells were not due to enhanced cell death, but rather due to G1-phase cell cycle arrest. Molecular studies revealed that EL- decreased mRNA or protein expression levels of the G1-phase promoters cyclin D1, cyclin E, cyclin-dependent kinases (CDK)-2, -4, and -6, and p-cdc25A; decreased phosphorylated retinoblastoma (p-pRb) protein levels; and simultaneously increased levels of p21WAF1/CIP1, a negative regulator of the G1-phase. The results suggest that EL inhibits the growth of NSCLC cell lines by down-regulating G1-phase cyclins and CDKs, and up-regulating p21WAF1/CIP1, which leads to G1-phase cell cycle arrest. Therefore, EL may hold promise as an adjuvant treatment for lung cancer therapy. PMID:28323486

Enterolactone Induces G1-phase Cell Cycle Arrest in Nonsmall Cell Lung Cancer Cells by Downregulating Cyclins and Cyclin-dependent Kinases.

PubMed

Chikara, Shireen; Lindsey, Kaitlin; Dhillon, Harsharan; Mamidi, Sujan; Kittilson, Jeffrey; Christofidou-Solomidou, Melpo; Reindl, Katie M

2017-01-01

Flaxseed is a rich source of the plant lignan secoisolariciresinol diglucoside (SDG), which is metabolized into mammalian lignans enterodiol (ED) and enterolactone (EL) in the digestive tract. The anticancer properties of these lignans have been demonstrated for various cancer types, but have not been studied for lung cancer. In this study, we investigated the anticancer effects of EL for several nonsmall cell lung cancer (NSCLC) cell lines of various genetic backgrounds. EL inhibited the growth of A549, H441, and H520 lung cancer cells in concentration- and time-dependent manners. The antiproliferative effects of EL for lung cancer cells were not due to enhanced cell death, but rather due to G 1 -phase cell cycle arrest. Molecular studies revealed that EL decreased mRNA or protein expression levels of the G 1 -phase promoters cyclin D1, cyclin E, cyclin-dependent kinases (CDK)-2, -4, and -6, and p-cdc25A; decreased phosphorylated retinoblastoma (p-pRb) protein levels; and simultaneously increased levels of p21 WAF1/CIP1 , a negative regulator of the G 1 phase. The results suggest that EL inhibits the growth of NSCLC cell lines by downregulating G 1 -phase cyclins and CDKs, and upregulating p21 WAF1/CIP1 , which leads to G 1 -phase cell cycle arrest. Therefore, EL may hold promise as an adjuvant treatment for lung cancer therapy.

shRNA-Mediated Silencing of Y-Box Binding Protein-1 (YB-1) Suppresses Growth of Neuroblastoma Cell SH-SY5Y In Vitro and In Vivo

PubMed Central

Wang, Hong; Sun, Ruowen; Gu, Min; Li, Shuang; Zhang, Bin; Chi, Zuofei; Hao, Liangchun

2015-01-01

Y-box binding protein-1 (YB-1), a member of cold-shock protein superfamily, has been demonstrated to be associated with tumor malignancy, and is proposed as a prognostic marker in multiple carcinomas. However, the role of YB-1 in neuroblastoma has not been well studied. To investigate the functional role of YB-1 in neuroblastoma, we established a YB-1-silenced neuroblastoma cell strain by inhibiting YB-1 expression using a shRNA knockdown approach. YB-1-silenced neuroblastoma SH-SY5Y cells exhibited a pronounced reduction in cell proliferation and an increased rate of apoptosis in vitro and in vivo xenograft tumor model. At molecular level, YB-1 silencing resulted in downregulation of Cyclin A, Cyclin D1 and Bcl-2, as well as upregulated levels of Bax, cleaved caspase-3 and cleaved PARP-1. We further demonstrated that YB-1 transcriptionally regulated Cyclin D1 expression by chromatin-immunoprecipitation and luciferase reporter assays. In addition, xenograft tumors derived from neuroblastoma SH-SY5Y cell line were treated with YB-1 shRNA plasmids by intra-tumor injection, and YB-1 targeting effectively inhibited tumor growth and induced cell death. In summary, our findings suggest that YB-1 plays a critical role in neuroblastoma development, and it may serve as a potential target for neuroblastoma therapy. PMID:25993060

Resveratrol induces cell cycle arrest and apoptosis in human eosinophils from asthmatic individuals.

PubMed

Hu, Xin; Wang, Jing; Xia, Yu; Simayi, Mihereguli; Ikramullah, Syed; He, Yuanbing; Cui, Shihong; Li, Shuang; Wushouer, Qimanguli

2016-12-01

Eosinophils exert a number of inflammatory effects through the degranulation and release of intracellular mediators, and are considered to be key effector cells in allergic disorders, including asthma. In order to investigate the regulatory effects of the natural polyphenol, resveratrol, on eosinophils derived from asthmatic individuals, the cell counting Kit‑8 assay and flow cytometry analysis were used to determine cell proliferation and cell cycle progression in these cells, respectively. Cellular apoptosis was detected using annexin V-fluorescein isothiocyanate/propidium iodide double‑staining. The protein expression levels of p53, p21, cyclin‑dependent kinase 2 (CDK2), cyclin A, cyclin E, Bim, B‑cell lymphoma (Bcl)‑2 and Bcl‑2‑associated X protein (Bax) were measured by western blot analysis following resveratrol treatment. The results indicated that resveratrol effectively suppressed the proliferation of eosinophils from asthmatic patients in a concentration‑ and time‑dependent manner. In addition, resveratrol was observed to arrest cell cycle progression in G1/S phase by increasing the protein expression levels of p53 and p21, and concurrently reducing the protein expression levels of CDK2, cyclin A and cyclin E. Furthermore, resveratrol treatment significantly induced apoptosis in eosinophils, likely through the upregulation of Bim and Bax protein expression levels and the downregulation of Bcl‑2 protein expression. These findings suggested that resveratrol may be a potential agent for the treatment of asthma by decreasing the number of eosinophils.

The IL-33-ST2-MyD88 axis promotes regulatory T cell proliferation in the murine liver.

PubMed

Xu, Lei; Li, Wei; Wang, Xiaofan; Zhang, Lina; Qi, Qianqian; Dong, Liyang; Wei, Chuan; Pu, Yanan; Li, Yalin; Zhu, Jifeng; Zhou, Sha; Liu, Feng; Chen, Xiaojun; Su, Chuan

2018-05-05

Hepatic Foxp3 + regulatory T (Treg) cells are crucial for maintaining local immune homeostasis in the liver. However, the environmental cues required for hepatic Treg cell homeostasis are unclear. In this study, we showed that the IL-33 receptor ST2 was preferentially expressed on Treg cells in the mouse liver, but it was more lowly expressed in the spleen, mesenteric lymph nodes, and blood. More importantly, we found that IL-33 promoted the proliferation of hepatic Treg cells through myeloid differentiation factor MyD88 signaling concomitant with increased CDK4 and cyclin D1 expression. These results suggested that IL-33 is a potential tissue-specific factor controlling Treg cell homeostasis via increased Treg proliferation in the liver. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

PPARδ INDUCES CELL PROLIFERATION BY A CYCLIN E1-DEPENDENT MECHANISM AND IS UPREGULATED IN THYROID TUMORS

PubMed Central

Zeng, Lingchun; Geng, Yan; Tretiakova, Maria; Yu, Xuemei; Sicinski, Peter; Kroll, Todd G.

2008-01-01

Peroxisome proliferator-activated receptors (PPARs) are lipid sensing nuclear receptors that have been implicated in multiple physiologic processes including cancer. Here, we determine that PPARδ induces cell proliferation through a novel cyclin E1-dependent mechanism and is upregulated in many human thyroid tumors. The expression of PPARδ was induced coordinately with proliferation in primary human thyroid cells by activation of serum, TSH/cAMP/pKa or EGF/MEK/ERK mitogenic signaling pathways. Engineered overexpression of PPARδ increased thyroid cell number, the incorporation of BrdU and the phosphorylation of Rb 40–45% in just 2 days, one usual cell population doubling. The synthetic PPARδ agonist GW501516 augmented these PPARδ proliferation effects in a dose-dependent manner. Overexpression of PPARδ increased cyclin E1 protein 9-fold, whereas knock down of PPARδ by siRNA reduced both cyclin E1 protein and cell proliferation 2-fold. Induction of proliferation by PPARδ wasabrogated by knockdown of cyclin E1 by siRNA in primary thyroid cells and by knockout of cyclin E1 in mouse embryo fibroblasts, confirming a cyclin E1 dependence for this PPARδ pathway. In addition, the mean expression of native PPARδ was increased 2- to 5-fold (p<0.0001) and correlated with that of the in situ proliferation marker Ki67 (R=0.8571; p=0.02381) in six different classes of benign and malignant human thyroid tumors. Our experiments identify a PPARδ mechanism that induces cell proliferation through cyclin E1 and is regulated by growth factor and lipid signals. The data argue for systematic investigation of PPARδ antagonists as anti-neoplastic agents and implicate altered PPARδ-cyclin E1 signaling in thyroid and other carcinomas. PMID:18701481

Cortactin modulates RhoA activation and expression of Cip/Kip cyclin-dependent kinase inhibitors to promote cell cycle progression in 11q13-amplified head and neck squamous cell carcinoma cells.

PubMed

Croucher, David R; Rickwood, Danny; Tactacan, Carole M; Musgrove, Elizabeth A; Daly, Roger J

2010-11-01

The cortactin oncoprotein is frequently overexpressed in head and neck squamous cell carcinoma (HNSCC), often due to amplification of the encoding gene (CTTN). While cortactin overexpression enhances invasive potential, recent research indicates that it also promotes cell proliferation, but how cortactin regulates the cell cycle machinery is unclear. In this article we report that stable short hairpin RNA-mediated cortactin knockdown in the 11q13-amplified cell line FaDu led to increased expression of the Cip/Kip cyclin-dependent kinase inhibitors (CDKIs) p21(WAF1/Cip1), p27(Kip1), and p57(Kip2) and inhibition of S-phase entry. These effects were associated with increased binding of p21(WAF1/Cip1) and p27(Kip1) to cyclin D1- and E1-containing complexes and decreased retinoblastoma protein phosphorylation. Cortactin regulated expression of p21(WAF1/Cip1) and p27(Kip1) at the transcriptional and posttranscriptional levels, respectively. The direct roles of p21(WAF1/Cip1), p27(Kip1), and p57(Kip2) downstream of cortactin were confirmed by the transient knockdown of each CDKI by specific small interfering RNAs, which led to partial rescue of cell cycle progression. Interestingly, FaDu cells with reduced cortactin levels also exhibited a significant diminution in RhoA expression and activity, together with decreased expression of Skp2, a critical component of the SCF ubiquitin ligase that targets p27(Kip1) and p57(Kip2) for degradation. Transient knockdown of RhoA in FaDu cells decreased expression of Skp2, enhanced the level of Cip/Kip CDKIs, and attenuated S-phase entry. These findings identify a novel mechanism for regulation of proliferation in 11q13-amplified HNSCC cells, in which overexpressed cortactin acts via RhoA to decrease expression of Cip/Kip CDKIs, and highlight Skp2 as a downstream effector for RhoA in this process.

Deoxynivalenol induced mouse skin cell proliferation and inflammation via MAPK pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mishra, Sakshi; Department of Biochemistry, Banaras Hindu University; Tripathi, Anurag

Several toxicological manifestations of deoxynivalenol (DON), a mycotoxin, are well documented; however, dermal toxicity is not yet explored. The effect of topical application of DON to mice was studied using markers of skin proliferation, inflammation and tumor promotion. Single topical application of DON (84–672 nmol/mouse) significantly enhanced dermal hyperplasia and skin edema. DON (336 and 672 nmol) caused significant enhancement in [{sup 3}H]-thymidine uptake in DNA along with increased myeloperoxidase and ornithine decarboxylase activities, suggesting tissue inflammation and cell proliferation. Furthermore, DON (168 nmol) caused enhanced expression of RAS, and phosphorylation of PI3K/Akt, ERK, JNK and p38 MAPKs. DON exposuremore » also showed activation of transcription factors, c-fos, c-jun and NF-κB along with phosphorylation of IkBα. Enhanced phosphorylation of NF-κB by DON caused over expression of target proteins, COX-2, cyclin D1 and iNOS in skin. Though a single topical application of DMBA followed by twice weekly application of DON (84 and 168 nmol) showed no tumorigenesis after 24 weeks, however, histopathological studies suggested hyperplasia of the epidermis and hypertrophy of hair follicles. Interestingly, intestine was also found to be affected as enlarged Peyer's patches were observed, suggesting inflammatory effects which were supported by elevation of inflammatory cytokines after 24 weeks of topical application of DON. These results suggest that DON induced cell proliferation in mouse skin is through the activation of MAPK signaling pathway involving transcription factors NFκB and AP-1, further leading to transcriptional activation of downstream target proteins c-fos, c-jun, cyclin D1, iNOS and COX-2 which might be responsible for its inflammatory potential. - Highlights: • Topical application of DON enhanced epidermal inflammation and cell proliferation. • DON follows PI3K/Akt/MAPK signaling cascade, with activation of AP-1 and NF-κB. • DON caused over expression of target proteins, COX-2, cyclin D1 and iNOS in skin. • No tumor promotion was observed up to 24 weeks of topical application of DON. • Enhanced Peyer's patches and inflammatory cytokines suggested inflammation in skin.« less

c-Myc plays a key role in TADs-induced apoptosis and cell cycle arrest in human hepatocellular carcinoma cells.

PubMed

Zhang, Dongdong; Qi, Junpeng; Liu, Rui; Dai, Bingling; Ma, Weina; Zhan, Yingzhuan; Zhang, Yanmin

2015-01-01

Cancer cell growth is complicated progression which is regulated and controlled by multiple factors including cell cycle, migration and apoptosis. In present study, we report that TADs, a novel derivative of taspine, has an essential role in resisting hepatocellular carcinoma growth (including arrest cell cycle) and migration, and inducing cell apoptosis. Our findings demonstrated that the TADs showed good inhibition on the hepatoma cell growth and migration, and good action on apoptosis induction. Using genome-wide microarray analysis, we found the down-regulated growth and apoptosis factors, and selected down-regulated genes were confirmed by Western blot. Knockdown of a checkpoint c-Myc by siRNA significantly attenuated tumor inhibition and apoptosis effects of TADs. Moreover, our results indicated TADs could simultaneously increase cyclin D1 protein levels and decrease amount of cyclin E, cyclin B1 and cdc2 of the cycle proteins, and also TADs reduced Bcl-2 expression, and upregulated Bad, Bak and Bax activities. In conclusion, these results illustrated that TADs is a key factor in growth and apoptosis signaling inhibitor, has potential in cancer therapy.

Nuclear expression and gain-of-function β-catenin mutation in glomangiopericytoma (sinonasal-type hemangiopericytoma): insight into pathogenesis and a diagnostic marker.

PubMed

Lasota, Jerzy; Felisiak-Golabek, Anna; Aly, F Zahra; Wang, Zeng-Feng; Thompson, Lester D R; Miettinen, Markku

2015-05-01

Glomangiopericytoma (sinonasal-type hemangiopericytoma) is a rare mesenchymal neoplasm with myoid phenotype (smooth muscle actin-positive), which distinguishes this tumor from soft tissue hemangiopericytoma/solitary fibrous tumor. Molecular genetic changes underlying the pathogenesis of glomangiopericytoma are not known. In this study, 13 well-characterized glomangiopericytomas were immunohistochemically evaluated for β-catenin expression. All analyzed tumors showed strong expression and nuclear accumulation of β-catenin. Following this observation, β-catenin glycogen serine kinase-3 beta phosphorylation region, encoded by exon 3, was PCR amplified in all cases and evaluated for mutations using Sanger sequencing. Heterozygous mutations were identified in 12 of 13 tumors. All mutations consisted of single-nucleotide substitutions: three in codon 32 (c.94G>C (n=2) and c.95A>T), four in codon 33 (two each c.98C>G and c.98C>T), two in codon 37 (c.109T>G), one in codon 41 (c.121A>G), and two in codon 45 (c.133T>C). At the protein level, these substitutions would lead to p.D32H, p.D32V, p.S33C, p.S33F, p.S37A, p.T41A, and p.S45L mutations, respectively. Previously, similar mutations have been reported in different types of cancers and shown to trigger activation of β-catenin signaling. All analyzed glomangiopericytomas showed prominent nuclear expression of cyclin D1, as previously shown for tumors with nuclear expression of β-catenin as a sign of oncogenic activation. These results demonstrate that mutational activation of β-catenin and associated cyclin D1 overexpression may be central events in the pathogenesis of glomangiopericytoma. In additon, nuclear accumulation of β-catenin is a diagnostic marker for glomangiopericytoma.

Co-culture with Sertoli cells promotes proliferation and migration of umbilical cord mesenchymal stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Fenxi, E-mail: fxzhang0824@gmail.com; Hong, Yan; Liang, Wenmei

Highlights: Black-Right-Pointing-Pointer Co-culture of Sertoli cells (SCs) with human umbilical cord mesenchymal stem cells (UCMSCs). Black-Right-Pointing-Pointer Presence of SCs dramatically increased proliferation and migration of UCMSCs. Black-Right-Pointing-Pointer Presence of SCs stimulated expression of Mdm2, Akt, CDC2, Cyclin D, CXCR4, MAPKs. -- Abstract: Human umbilical cord mesenchymal stem cells (hUCMSCs) have been recently used in transplant therapy. The proliferation and migration of MSCs are the determinants of the efficiency of MSC transplant therapy. Sertoli cells are a kind of 'nurse' cells that support the development of sperm cells. Recent studies show that Sertoli cells promote proliferation of endothelial cells and neuralmore » stem cells in co-culture. We hypothesized that co-culture of UCMSCs with Sertoli cells may also promote proliferation and migration of UCMSCs. To examine this hypothesis, we isolated UCMSCs from human cords and Sertoli cells from mouse testes, and co-cultured them using a Transwell system. We found that UCMSCs exhibited strong proliferation ability and potential to differentiate to other cell lineages such as osteocytes and adipocytes. The presence of Sertoli cells in co-culture significantly enhanced the proliferation and migration potential of UCMSCs (P < 0.01). Moreover, these phenotypic changes were accompanied with upregulation of multiple genes involved in cell proliferation and migration including phospho-Akt, Mdm2, phospho-CDC2, Cyclin D1, Cyclin D3 as well as CXCR4, phospho-p44 MAPK and phospho-p38 MAPK. These findings indicate that Sertoli cells boost UCMSC proliferation and migration potential.« less

PPARδ agonist GW501516 inhibits PDGF-stimulated pulmonary arterial smooth muscle cell function related to pathological vascular remodeling.

PubMed

Liu, Guangjie; Li, Xuan; Li, Yan; Tang, Xin; Xu, Jie; Li, Ran; Hao, Peng; Sun, Yongchang

2013-01-01

Pulmonary arterial hypertension (PAH) is a severe and progressive disease, a key feature of which is pulmonary vascular remodeling. Growth factors, cytokines, and lipid mediators are involved in this remodeling process. Recent reports suggest that the peroxisome proliferator-activated receptors (PPARs) play important roles in the regulation of cell growth and differentiation as well as tissue wounding and repair. In this study, we examined the role of PPAR δ in the regulation of proliferation, migration, collagen synthesis, and chemokine production in human pulmonary arterial smooth muscle cells (HPASMCs). The data showed that PPAR δ was the most abundant isoform in HPASMCs. PPAR δ was upregulated in HPASMCs treated with PDGF, which is the major mediator in pulmonary vascular remodeling. Activation of PPAR δ by GW501516, a specific PPAR δ ligand, significantly inhibited PDGF-induced proliferation in HPASMCs. The inhibitory effect of GW501516 on HPASMCs was associated with decreased expression of cyclin D1, cyclin D3, CDK2, and CDK4 as well as increased expression of the cell cycle inhibitory genes G0S2 and P27(kip1). Pretreatment of HPASMCs with GW501516 significantly inhibited PDGF-induced cell migration and collagen synthesis. GW501516 also significantly attenuated TNF-mediated expression of MCP-1. These results suggest that PPAR δ may be a potential therapeutic target against the progression of vascular remodeling in PAH.

PPARδ Agonist GW501516 Inhibits PDGF-Stimulated Pulmonary Arterial Smooth Muscle Cell Function Related to Pathological Vascular Remodeling

PubMed Central

Liu, Guangjie; Li, Xuan; Li, Yan; Tang, Xin; Xu, Jie; Li, Ran; Hao, Peng; Sun, Yongchang

2013-01-01

Pulmonary arterial hypertension (PAH) is a severe and progressive disease, a key feature of which is pulmonary vascular remodeling. Growth factors, cytokines, and lipid mediators are involved in this remodeling process. Recent reports suggest that the peroxisome proliferator-activated receptors (PPARs) play important roles in the regulation of cell growth and differentiation as well as tissue wounding and repair. In this study, we examined the role of PPARδ in the regulation of proliferation, migration, collagen synthesis, and chemokine production in human pulmonary arterial smooth muscle cells (HPASMCs). The data showed that PPARδ was the most abundant isoform in HPASMCs. PPARδ was upregulated in HPASMCs treated with PDGF, which is the major mediator in pulmonary vascular remodeling. Activation of PPARδ by GW501516, a specific PPARδ ligand, significantly inhibited PDGF-induced proliferation in HPASMCs. The inhibitory effect of GW501516 on HPASMCs was associated with decreased expression of cyclin D1, cyclin D3, CDK2, and CDK4 as well as increased expression of the cell cycle inhibitory genes G0S2 and P27kip1. Pretreatment of HPASMCs with GW501516 significantly inhibited PDGF-induced cell migration and collagen synthesis. GW501516 also significantly attenuated TNF-mediated expression of MCP-1. These results suggest that PPARδ may be a potential therapeutic target against the progression of vascular remodeling in PAH. PMID:23607100

Identification and characterization of the BmCyclin L1-BmCDK11A/B complex in relation to cell cycle regulation.

PubMed

Liu, Tai-Hang; Wu, Yun-Fei; Dong, Xiao-Long; Pan, Cai-Xia; Du, Guo-Yu; Yang, Ji-Gui; Wang, Wei; Bao, Xi-Yan; Chen, Peng; Pan, Min-Hui; Lu, Cheng

2017-05-03

Cyclin proteins are the key regulatory and activity partner of cyclin-dependent kinases (CDKs), which play pivotal regulatory roles in cell cycle progression. In the present study, we identified a Cyclin L1 and 2 CDK11 2 CDK11 splice variants, CDK11A and CDK11B, from silkworm, Bombyx mori. We determined that both Cyclin L1 and CDK11A/B are nuclear proteins, and further investigations were conducted to elucidate their spatiofunctional features. Cyclin L1 forms a complex with CDK11A/B and were co-localized to the nucleus. Moreover, the dimerization of CDK11A and CDK11B and the effects of Cyclin L1 and CDK11A/B on cell cycle regulation were also investigated. Using overexpression or RNA interference experiments, we demonstrated that the abnormal expression of Cyclin L1 and CDK11A/B leads to cell cycle arrest and cell proliferation suppression. Together, these findings indicate that CDK11A/B interacts with Cyclin L1 to regulate the cell cycle.

Cellular conservation of endangered midget buffalo (Lowland Anoa, Bubalus quarlesi) by establishment of primary cultured cell, and its immortalization with expression of cell cycle regulators.

PubMed

Fukuda, Tomokazu; Iino, Yuuka; Eitsuka, Takahiro; Onuma, Manabu; Katayama, Masafumi; Murata, Koichi; Inoue-Murayama, Miho; Hara, Kumiko; Isogai, Emiko; Kiyono, Tohru

2016-10-01

Lowland Anoa has become endangered due to hunting and human activity. Protection and breeding of endangered species in a controlled environment is the best way of conservation. However, it is not possible to adopt this approach for all endangered species because of the cost involved and the ever-increasing number of critically endangered species. In consideration of these limitations to the conventional conservation methods, we established a primary cell culture of endangered buffalo (Lowland Anoa, Bubalus quarlesi), for the preservation of this biological resource. In addition, we introduced human derived, mutant cyclin dependent kinase 4 (CDK4), Cyclin D, and telomerase reverse transcriptase (TERT) into the primary cells. The successful introduction of these three genes was confirmed by western blot with specific antibodies, and enzymatic activity. We also showed that the expression of mutant CDK4, Cyclin D, and TERT allows us to efficiently establish an immortalized cell line, with an intact chromosome pattern, from Lowland Anoa. To the best of our knowledge, this study is the first investigation that established an immortalized cell line of an endangered wild animal species.

Histological characterization of regression in acquired immunodeficiency syndrome-related Kaposi's sarcoma.

PubMed

Pantanowitz, Liron; Dezube, Bruce J; Pinkus, Geraldine S; Tahan, Steven R

2004-01-01

Kaposi's sarcoma (KS) is an angioproliferative lesion that may regress or progress. Progression is related to spindle cell proliferation and the expression of human herpes virus-8 latency genes, including latent nuclear antigen-1 (LNA-1), cyclin-D1, and bcl-2. KS regression has not been well characterized histologically. Therefore, this study was undertaken to characterize the histopathology of pharmacologically induced regressed cutaneous KS. Skin punch biopsies from eight patients with acquired immunodeficiency syndrome (AIDS)-related KS, that regressed following chemotherapy with paclitaxel or the angiogenesis inhibitor Col-3, were investigated by light microscopy. Comparative immunophenotyping on pre- and post-treatment specimens for CD31, LNA-1, cyclin-D1, bcl-2, and CD117 (c-kit) was performed. Clinical and histologic features of regression were similar for paclitaxel and Col-3 treatment. On clinical examination, lesions flattened, became smaller, and lost their purple-red appearance, resulting in an orange-brown macule. Histological regression was divided into partial (n = 3) and complete (n = 5) regression. Partially regressed lesions had a significant reduction of spindle cells in the dermal interstitium, with residual spindle cells arranged around superficial and mid-dermal capillaries. Complete regression was characterized by an absence of detectable spindle cells, with a slight increase in capillaries of the superficial plexus. All regressed samples exhibited a prominent, superficial, perivascular, lymphocytic infiltrate and abundant dermal hemosiderin-laden macrophages. This clinicopathologic picture resembled the findings of pigmented purpura. CD31 staining correlated with the reduction of spindle cells. Regression was accompanied by a quantitative and qualitative decrease in LNA-1 and cyclin-D1 immunoreactivity, but no change in bcl-2 or c-kit expression. Pharmacologically induced regression of AIDS-related cutaneous KS is characterized by a complete loss or decrease of spindle cells, increased lymphocytes, and prominent dermal siderophage deposition. Without any prior knowledge of the history of KS regression following therapy, regressed KS lesions may be misdiagnosed clinically and histologically as pigmented purpuric dermatitis.

Aspirin regulation of c-myc and cyclinD1 proteins to overcome tamoxifen resistance in estrogen receptor-positive breast cancer cells.

PubMed

Cheng, Ran; Liu, Ya-Jing; Cui, Jun-Wei; Yang, Man; Liu, Xiao-Ling; Li, Peng; Wang, Zhan; Zhu, Li-Zhang; Lu, Si-Yi; Zou, Li; Wu, Xiao-Qin; Li, Yu-Xia; Zhou, You; Fang, Zheng-Yu; Wei, Wei

2017-05-02

Tamoxifen is still the most commonly used endocrine therapy drug for estrogen receptor (ER)-positive breast cancer patients and has an excellent outcome, but tamoxifen resistance remains a great impediment to successful treatment. Recent studies have prompted an anti-tumor effect of aspirin. Here, we demonstrated that aspirin not only inhibits the growth of ER-positive breast cancer cell line MCF-7, especially when combined with tamoxifen, but also has a potential function to overcome tamoxifen resistance in MCF-7/TAM. Aspirin combined with tamoxifen can down regulate cyclinD1 and block cell cycle in G0/G1 phase. Besides, tamoxifen alone represses c-myc, progesterone receptor (PR) and cyclinD1 in MCF-7 cell line but not in MCF-7/TAM, while aspirin combined with tamoxifen can inhibit the expression of these proteins in the resistant cell line. When knocking down c-myc in MCF-7/TAM, cells become more sensitive to tamoxifen, cell cycle is blocked as well, indicating that aspirin can regulate c-myc and cyclinD1 proteins to overcome tamoxifen resistance. Our study discovered a novel role of aspirin based on its anti-tumor effect, and put forward some kinds of possible mechanisms of tamoxifen resistance in ER-positive breast cancer cells, providing a new strategy for the treatment of ER-positive breast carcinoma.

Squamous epithelial proliferation induced by walleye dermal sarcoma retrovirus cyclin in transgenic mice

PubMed Central

Lairmore, Michael D.; Stanley, James R.; Weber, Stacy A.; Holzschu, Donald L.

2000-01-01

Walleye dermal sarcoma (WDS) is a common disease of walleye fish in the United States and Canada. These proliferative lesions are present autumn through winter and regress in the spring. Walleye dermal sarcoma virus (WDSV), a retrovirus distantly related to other members of the family Retroviridae, has been etiologically linked to the development of WDS. We have reported that the D-cyclin homologue [retroviral (rv) cyclin] encoded by WDSV rescues yeast conditionally deficient for cyclin synthesis from growth arrest and that WDSV-cyclin mRNA is present in developing tumors. These data strongly suggest that the rv-cyclin plays a central role in the development of WDS. To test the ability of the WDSV rv-cyclin to induce cell proliferation, we have generated transgenic mice expressing the rv-cyclin in squamous epithelia from the bovine keratin-5 promoter. The transgenic animals were smaller than littermates, had reduced numbers of hair follicles, and transgenic females did not lactate properly. Following injury the transgenic animals developed severe squamous epithelial hyperplasia and dysplasia with ultrastructural characteristics of neoplastic squamous epithelium. Immunocytochemistry studies demonstrated that the hyperplastic epithelium stained positive for cytokeratin and were abnormally differentiated. Furthermore, the rv-cyclin protein was detected in the thickened basal cell layers of the proliferating lesions. These data are the first to indicate that the highly divergent WDSV rv-cyclin is a very potent stimulator of eukaryotic cell proliferation and to demonstrate the potential of a cyclin homologue encoded by a retrovirus to induce hyperplastic skin lesions. PMID:10811912

Simultaneous knockdown of BRAF and expression of INK4A in melanoma cells leads to potent growth inhibition and apoptosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao Yanhua; Zhang Yan; Yang Zhen

2008-06-06

Abnormal BRAF and p16INK4A co-exist in 60% of melanomas. BRAF mutation also occurs in 80% of benign nevi where it turns-on p16INK4A resulting in proliferative senescence; loss of p16INK4A removes the inhibitory block leading to melanoma development. Since only melanomas with wild-type BRAF have amplified CDK4 and cyclin D1 genes, p16INK4A-CDK4/6-cyclin D pathway is viewed as linearly downstream of BRAF. Thus, co-occurrence of aberrant BRAF and INK4A may be remnant of changes during melanoma formation without functional significance. To explore this notion, we simultaneously knocked down BRAF (via siRNA) and expressed INK4A cDNA in melanoma cells and observed enhanced growthmore » inhibition. Notably, although each alone had no statistically significant effect on apoptosis, co-expression of BRAF siRNA and INK4A cDNA caused potent apoptosis, which was associated with up-regulation of BIM and down-regulation of BCL2. Our results suggest that aberrant BRAF and INK4A cooperate to promote proliferation and survival of melanoma cells.« less

Correlations between radiation-induced double strand breaks, cell division delay, and cyclin-dependent signaling in x-irradiated NIH3T3 fibroblasts

NASA Astrophysics Data System (ADS)

Cariveau, Mickael J.

2005-07-01

Molecular responses to radiation-induced DNA double strand breaks (DSB) are mediated by the phosphorylation of the histone variant H2AX which forms identifiable gamma-H2AX foci at the site of the DSB. This event is thought to be linked with the down-regulation of signaling proteins contributing to the checkpoints regulating cell cycle progression and, vis-a-vis , the induction of cell division delay. However, it is unclear whether this division delay is directly related to the number of DSB (gamma-H2AX foci) sustained by an irradiated cell and, if so, whether this number drives cells into cell cycle delay or apoptosis. For this reason, studies were conducted in the immortalized NIH/3T3 fibroblast cell in order to establish correlations between the temporal appearance of the gamma-H2AX foci (a DSB) and the expression of the cell cycle regulatory proteins, cyclin E, A, B1, and their cyclin kinase inhibitor, p21. Cell cycle kinetics and flow cytometry were used to establish radiation-induced division delay over a dose range of 1--6 Gy where a mitotic delay of 2.65 min/cGy was established. Correlations between the expression of cyclin E, A, B1, p21, and the generation of DSB were established in NIH/3T3 cells exposed to 2 or 4 Gy x-irradiation. The data suggest that the G1/S and S phase delay (cyclin E and cyclin A protein levels) are dependent on the dose of radiation while the G2/M (cyclin B1 protein levels) delay is dependent on the quantity of DSB sustained by the irradiated cell.

MicroRNA-466 (miR-466) functions as a tumor suppressor and prognostic factor in colorectal cancer (CRC).

PubMed

Tong, Feng; Ying, Youhua; Pan, Haihua; Zhao, Wei; Li, Hongchen; Zhan, Xiaoli

2018-01-17

MicroRNAs (miRNAs) have an important role in the regulation of tumor development and metastasis. In this study, we investigated the clinical and prognostic value as well as biological function of miR-466 in colorectal cancer (CRC). Tumor and adjacent healthy tissues were obtained from 100 patients diagnosed with CRC. miR-466 expression was determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR). mRNA and protein levels of cyclin D1, apoptosis regulator BAX (BAX), and matrix metalloproteinase-2 (MMP-2) were analyzed by qRT-PCR and Western blot, respectively, in SW-620 CRC cells transfected with miR-466 mimics or negative control miRNA. Effects of miR-466 on SW-620 cell proliferation, cell cycle and apoptosis, and invasion were investigated using CCK-8 assay, flow cytometry and Transwell assay, respectively. miR-466 expression was significantly downregulated in tumor tissues compared to matched adjacent non-tumor tissues. Low expression of miR-466 was significantly correlated with the tumor size, Tumor Node Metastasis stage, lymph node metastasis, and distant metastasis. The overall survival of CRC patients with low miR-466 expression was significantly shorter compared to high-miR-466 expression group (log-rank test: p = 0.0103). Multivariate analysis revealed that low miR-466 expression was associated with poor prognosis in CRC patients. The ectopic expression of miR-466 suppressed cell proliferation and migration/invasion, as well as induced G0/G1 arrest and apoptosis in SW-620 cells. Moreover, the ectopic expression of miR-466 decreased the expression of cyclin D1 and MMP-2, but increased BAX expression in SW-620 cells. In conclusion, our findings demonstrated that miR-466 functions as a suppressor miRNA in CRC and may be used as a prognostic factor in these patients.

The Mucin MUC4 and Its Membrane Partner ErbB2 Regulate Biological Properties of Human CAPAN-2 Pancreatic Cancer Cells via Different Signalling Pathways

PubMed Central

Jonckheere, Nicolas; Skrypek, Nicolas; Merlin, Johann; Dessein, Anne Frédérique; Dumont, Patrick; Leteurtre, Emmanuelle; Harris, Ann; Desseyn, Jean-Luc; Susini, Christiane; Frénois, Frédéric; Van Seuningen, Isabelle

2012-01-01

The mucin MUC4 and its membrane partner the ErbB2 oncogenic receptor are potential interacting partners in human pancreatic tumour development. However, the way they function is still largely unknown. In this work, we aimed to identify the cellular mechanisms and the intracellular signalling pathways under the control of both ErbB2 and MUC4 in a human pancreatic adenocarcinomatous cell line. Using co-immunoprecipitation and GST pull-down, we show that MUC4 and ErbB2 interact in the human pancreatic adenocarcinomatous cell line CAPAN-2 via the EGF domains of MUC4. Stable cell clones were generated in which either MUC4 or ErbB2 were knocked down (KD) by a shRNA approach. Biological properties of these cells were then studied in vitro and in vivo. Our results show that ErbB2-KD cells are more apoptotic and less proliferative (decreased cyclin D1 and increased p27kip1 expression) while migration and invasive properties were not altered. MUC4-KD clones were less proliferative with decreased cyclin D1 expression, G1 cell cycle arrest and altered ErbB2/ErbB3 expression. Their migration properties were reduced whereas invasive properties were increased. Importantly, inhibition of ErbB2 and MUC4 expression did not impair the same signalling pathways (inhibition of MUC4 expression affected the JNK pathway whereas that of ErbB2 altered the MAPK pathway). Finally, ErbB2-KD and MUC4-KD cells showed impaired tumour growth in vivo. Our results show that ErbB2 and MUC4, which interact physically, activate different intracellular signalling pathways to regulate biological properties of CAPAN-2 pancreatic cancer cells. PMID:22393391

Frequent β-catenin gene mutations in atypical polypoid adenomyoma of the uterus.

PubMed

Takahashi, Hiroyuki; Yoshida, Tsutomu; Matsumoto, Toshihide; Kameda, Yoichi; Takano, Yasuo; Tazo, Yuki; Inoue, Hisako; Saegusa, Makoto

2014-01-01

Atypical polypoid adenomyoma (APA) is an uncommon polypoid lesion of the uterus. To clarify the mechanism of its histogenesis, we examined the functional role of β-catenin, with reference to expression of p21(waf1), cyclin D1, cyclin E, CD10, and α-smooth muscle actin (SMA), as well as cell proliferation, in 7 lesions. In the epithelial components, expression of nuclear β-catenin, p21(waf1), and cyclin D1 was increased in a stepwise fashion from normal tissue through complex atypical hyperplasia and adenomyoma to APA lesions, particularly in squamous morular areas, whereas cell proliferation, as well as cyclin E expression, was significantly decreased in the latter. Similar findings were evident in the stromal lesions, with the exception of a case of nuclear β-catenin. In addition, coexpression of CD10 and α-SMA markers was observed in the stromal components in 3 APA cases, in line with the results of normal secretory endometrial and adenomyoma samples, suggesting that cells progress to myofibromatous cells in response to differentiation-promoting events. Finally, β-catenin gene (CTNNB1) mutations were detected in all APA cases, the single nucleotide substitutions being in the epithelial but not the stromal components. These findings suggest that activation of β-catenin signaling, probably secondary to the gene abnormalities, plays an important role in the formation of the complex epithelial architecture in APAs, leading to inhibition of cell proliferation through overexpression of p21(waf1). In contrast, changes in the stromal cell phenotype may occur through a shift from CD10 to α-SMA immunopositivity, independent of CTNNB1 status. © 2013.

Molecular basis for the regulation of islet beta cell mass in mice: the role of E-cadherin

PubMed Central

Wakae-Takada, N.; Xuan, S.; Watanabe, K.; Meda, P.; Leibel, R. L.

2014-01-01

Aims/hypothesis In rodents and humans, the rate of beta cell proliferation declines rapidly after birth; formation of the islets of Langerhans begins perinatally and continues after birth. Here, we tested the hypothesis that increasing levels of E-cadherin during islet formation mediate the decline in beta cell proliferation rate by contributing to a reduction of nuclear β-catenin and D-cyclins. Methods We examined E-cadherin, nuclear β-catenin, and D-cyclin levels, as well as cell proliferation during in vitro and in vivo formation of islet cell aggregates, using β-TC6 cells and transgenic mice with green fluorescent protein (GFP)-labelled beta cells, respectively. We tested the role of E-cadherin using antisense-mediated reductions of E-cadherin in β-TC6 cells, and mice segregating for a beta cell-specific E-cadherin knockout (Ecad [also known as Cdh1] βKO). Results In vitro, pseudo-islets of β-TC6 cells displayed increased E-cadherin but decreased nuclear β-catenin and cyclin D2, and reduced rates of cell proliferation, compared with monolayers. Antisense knockdown of E-cadherin increased cell proliferation and levels of cyclins D1 and D2. After birth, beta cells showed increased levels of E-cadherin, but decreased levels of D-cyclin, whereas islets of Ecad βKO mice showed increased levels of D-cyclins and nuclear β-catenin, as well as increased beta cell proliferation. These islets were significantly larger than those of control mice and displayed reduced levels of connexin 36. These changes correlated with reduced insulin response to ambient glucose, both in vitro and in vivo. Conclusions/interpretation The findings support our hypothesis by indicating an important role of E-cadherin in the control of beta cell mass and function. PMID:23354125

Molecular basis for the regulation of islet beta cell mass in mice: the role of E-cadherin.

PubMed

Wakae-Takada, N; Xuan, S; Watanabe, K; Meda, P; Leibel, R L

2013-04-01

In rodents and humans, the rate of beta cell proliferation declines rapidly after birth; formation of the islets of Langerhans begins perinatally and continues after birth. Here, we tested the hypothesis that increasing levels of E-cadherin during islet formation mediate the decline in beta cell proliferation rate by contributing to a reduction of nuclear β-catenin and D-cyclins. We examined E-cadherin, nuclear β-catenin, and D-cyclin levels, as well as cell proliferation during in vitro and in vivo formation of islet cell aggregates, using β-TC6 cells and transgenic mice with green fluorescent protein (GFP)-labelled beta cells, respectively. We tested the role of E-cadherin using antisense-mediated reductions of E-cadherin in β-TC6 cells, and mice segregating for a beta cell-specific E-cadherin knockout (Ecad [also known as Cdh1] βKO). In vitro, pseudo-islets of β-TC6 cells displayed increased E-cadherin but decreased nuclear β-catenin and cyclin D2, and reduced rates of cell proliferation, compared with monolayers. Antisense knockdown of E-cadherin increased cell proliferation and levels of cyclins D1 and D2. After birth, beta cells showed increased levels of E-cadherin, but decreased levels of D-cyclin, whereas islets of Ecad βKO mice showed increased levels of D-cyclins and nuclear β-catenin, as well as increased beta cell proliferation. These islets were significantly larger than those of control mice and displayed reduced levels of connexin 36. These changes correlated with reduced insulin response to ambient glucose, both in vitro and in vivo. The findings support our hypothesis by indicating an important role of E-cadherin in the control of beta cell mass and function.

Cell cycle gene expression under clinorotation

NASA Astrophysics Data System (ADS)

Artemenko, Olga

2016-07-01

Cyclins and cyclin-dependent kinase (CDK) are main regulators of the cell cycle of eukaryotes. It's assumes a significant change of their level in cells under microgravity conditions and by other physical factors actions. The clinorotation use enables to determine the influence of gravity on simulated events in the cell during the cell cycle - exit from the state of quiet stage and promotion presynthetic phase (G1) and DNA synthesis phase (S) of the cell cycle. For the clinorotation effect study on cell proliferation activity is the necessary studies of molecular mechanisms of cell cycle regulation and development of plants under altered gravity condition. The activity of cyclin D, which is responsible for the events of the cell cycle in presynthetic phase can be controlled by the action of endogenous as well as exogenous factors, but clinorotation is one of the factors that influence on genes expression that regulate the cell cycle.These data can be used as a model for further research of cyclin - CDK complex for study of molecular mechanisms regulation of growth and proliferation. In this investigation we tried to summarize and analyze known literature and own data we obtained relatively the main regulators of the cell cycle in altered gravity condition.

CDK inhibitors, p21{sup Cip1} and p27{sup Kip1}, participate in cell cycle exit of mammalian cardiomyocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tane, Shoji; Ikenishi, Aiko; Okayama, Hitomi

2014-01-17

Highlights: •Expression of p21 and p27 in the hearts showed a peak during postnatal stages. •p21 and p27 bound to cyclin E, cyclin A and CDK2 in the hearts at postnatal stages. •Cardiomyocytes in both KO mice showed failure in the cell cycle exit at G1-phase. •These data show the first apparent phenotypes in the hearts of Cip/Kip KO mice. -- Abstract: Mammalian cardiomyocytes actively proliferate during embryonic stages, following which cardiomyocytes exit their cell cycle after birth. The irreversible cell cycle exit inhibits cardiac regeneration by the proliferation of pre-existing cardiomyocytes. Exactly how the cell cycle exit occurs remainsmore » largely unknown. Previously, we showed that cyclin E- and cyclin A-CDK activities are inhibited before the CDKs levels decrease in postnatal stages. This result suggests that factors such as CDK inhibitors (CKIs) inhibit CDK activities, and contribute to the cell cycle exit. In the present study, we focused on a Cip/Kip family, which can inhibit cyclin E- and cyclin A-CDK activities. Expression of p21{sup Cip1} and p27{sup Kip1} but not p57{sup Kip2} showed a peak around postnatal day 5, when cyclin E- and cyclin A-CDK activities start to decrease. p21{sup Cip1} and p27{sup Kip1} bound to cyclin E, cyclin A and CDK2 at postnatal stages. Cell cycle distribution patterns of postnatal cardiomyocytes in p21{sup Cip1} and p27{sup Kip1} knockout mice showed failure in the cell cycle exit at G1-phase, and endoreplication. These results indicate that p21{sup Cip1} and p27{sup Kip} play important roles in the cell cycle exit of postnatal cardiomyocytes.« less

Differential expression of miR16 in glioblastoma and glioblastoma stem cells: their correlation with proliferation, differentiation, metastasis and prognosis.

PubMed

Tian, R; Wang, J; Yan, H; Wu, J; Xu, Q; Zhan, X; Gui, Z; Ding, M; He, J

2017-10-19

The function of miR16 in multiforme glioblastoma multiforme (GBM) and its stem cells (GSCs) remains elusive. To this end, we investigated the patterns of miR16 expression in these cells and their correlation with malignant behaviors and clinical outcomes. The levels of miR16 and its targeted genes in tumor tissue of GBM and GBM SGH44, U87, U251 cells as well as their stem cell counterparts were measured by qRT-PCR or western blot or immunohistochemistry. Luciferase reporter assay was used to confirm the binding of miR16 to 3'-UTR of its target genes. The effects of miR16 on malignant behaviors were investigated, including tumor cell viability, soft-agar colony formation, GSCs Matrigel colony forming and migration and invasion as well as nude mice xenograft model. Differentially expression patterns of miR16 in glioblastoma cells and GSCs cells were found in this study. Changes of miR16 targeted genes, Bcl2 (B cell lymphoma 2), CDK6 (Cyclin-dependent kinase 6), CCND1 (cyclin D1), CCNE1 (cyclin E1) and SOX5 were confirmed in glioblastoma cell lines and tissue specimens. In vitro and in vivo studies showed that tumor cell proliferation was inhibited by miR16 mimic, but enhanced by miR16 inhibitor. The expression level of miR16 positively correlates with GSCs differentiation, but negatively with the abilities of migration, motility, invasion and colony formation in glioblastoma cells. The inhibitory effects of miR16 on its target genes were also found in nude mice xenograft model. Our findings revealed that the miR16 functions as a tumor suppressor in GSCs and its association with prognosis in GBM.

Attenuation of liver cancer development by oral glycerol supplementation in the rat.

PubMed

Capiglioni, Alejo M; Lorenzetti, Florencia; Quiroga, Ariel D; Parody, Juan P; Ronco, María T; Pisani, Gerardo B; Carrillo, María C; Ceballos, María P; Alvarez, María de Luján

2018-04-01

Glycerol usage is increasing in food industry for human and animal nutrition. This study analyzed the impact of glycerol metabolism when orally supplemented during the early stage of rat liver carcinogenesis. Wistar rats were subjected to a 2-phase model of hepatocarcinogenesis (initiated-promoted, IP group). IP animals also received glycerol by gavage (200 mg/kg body weight, IPGly group). Glycerol treatment reduced the volume of preneoplastic lesions by decreasing the proliferative status of liver foci, increasing the expression of p53 and p21 proteins and reducing the expression of cyclin D1 and cyclin-dependent kinase 1. Besides, apoptosis was enhanced in IPGly animals, given by an increment of Bax/Bcl-2 ratio, Bad and PUMA mitochondrial expression, a concomitant increase in cytochrome c release and caspase-3 activation. Furthermore, hepatic levels of glycerol phosphate and markers of oxidative stress were increased in IPGly rats. Oxidative stress intermediates act as intracellular messengers, inducing p53 activation and changes in JNK and Erk signaling pathways, with JNK activation and Erk inhibition. The present work provides novel data concerning the preventive actions of glycerol during the development of liver cancer and represents an economically feasible intervention to treat high-risk individuals.

PPAR{gamma} activation abolishes LDL-induced proliferation of human aortic smooth muscle cells via SOD-mediated down-regulation of superoxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heo, Kyung-Sun; Department of Pharmacy, Chungnam National University, Yuseong, Daejeon; Kim, Dong-Uk

Native LDL would be a mitogenic and chemotactic stimulus of VSMC proliferation and differentiation in the atherosclerotic lesion where endothelial disruption occurred. In previous studies, our group investigated the molecular mechanisms by which LDL induces IL-8 production and by which PPAR{alpha} activation abolishes LDL effects in human aortic SMCs (hAoSMCs). Herein is the first report of PPAR{gamma} activation by troglitazone (TG) exerting its inhibitory effects on LDL-induced cell proliferation via generation not of H{sub 2}O{sub 2}, but of O2?-, and the subsequent activation of Erk1/2 in hAoSMCs. Moreover, in this study TG abolished the LDL-accelerated G{sub 1}-S progression to controlmore » levels via down-regulation of active cyclinD1/CDK4 and cyclinE/CDK2 complexes and up-regulation of p21{sup Cip1} expression. TG exerted its anti-proliferative effects through the up-regulation of basal superoxide dismutase (SOD) expression. This data suggests that the regulation of O2?- is located at the crossroads between LDL signaling and cell proliferation.« less

A long noncoding RNA UCA1 promotes proliferation and predicts poor prognosis in glioma.

PubMed

Zhao, W; Sun, C; Cui, Z

2017-06-01

Acting as a proto-oncogene, long noncoding RNAs (lncRNAs) urothelial carcinoembryonic antigen 1 (UCA1) plays a key role in the occurrence and development of several human tumors. However, the expression and biological functions of UCA1 in glioma are less known. This study discussed the expression of UCA1 in glioma and its effect on the proliferation and cell cycle of glioma cells. LncRNA UCA1 expressions in 64 glioma samples (Grade I-II in 22 cases and Grade III-IV in 42 cases, according to WHO criteria) and 10 normal brain samples were detected using real-time fluorescence quantitative PCR. On this basis, the correlations of UCA1 to clinicopathological characteristics and prognosis of glioma were assessed. Then, using qPCR, the lncRNA UCA1 expressions in glioma cell lines and astrocytes were detected. UCA1-overexpressing glioma cell lines U87 and U251 were further detected after siRNA transfection of these two cell lines, and the impact on cell proliferation and cell cycle was assessed with CCK-8 (cell counting kit-8) assay and flow cytometry method (FCM), respectively. The expression of cyclin D1, a cell cycle-related protein, was detected using Western Blot. LncRNA UCA1 expression in the glioma samples was obviously higher as compared with the normal brain samples (P < 0.001), and the expression was correlated significantly with grading of the tumors (P < 0.05). However, lncRNA UCA1 expression was not correlated with age, gender, tumor size and KPS score (P > 0.05). After interference of UCA1 expression by siRNA transfection, the proliferation of both U251 and SHG-44 cells was inhibited (P < 0.05), with more cells arrested in G0/G1 (P < 0.05). Moreover, cyclin D1 expression was also downregulated considerably. LncRNA UCA1 can promote the proliferation and cell cycle progression of glioma cells by upregulating cyclin D1 transcription. So UCA1 may serve as an independent prognostic indicator and a novel therapeutic target for glioma.

Gravitational force modulates G2/M phase exit in mechanically unloaded myoblasts

PubMed Central

Benavides Damm, Tatiana; Franco-Obregón, Alfredo; Egli, Marcel

2013-01-01

Prolonged spaceflight gives rise to muscle loss and reduced strength, a condition commonly referred to as space atrophy. During exposure to microgravity, skeletal muscle myoblasts are mechanically unloaded and respond with attenuated cell proliferation, slowed cell cycle progression, and modified protein expression. To elucidate the underlying mechanisms by which muscle mass declines in response to prolonged microgravity exposure, we grew C2C12 mouse muscle cells under conditions of simulated microgravity (SM) and analyzed their proliferative capacity, cell cycle progression, and cyclin B and D expression. We demonstrated that the retarded cell growth observed in SM was correlated with an approximate 16 h delay in G2/M phase progression, where cells accumulated specifically between the G2 checkpoint and the onset of anaphase, concomitantly with a positive expression for cyclin B. The effect was specific for gravitational mechanical unloading as cells grown under conditions of hypergravity (HG, 4 g) for similar durations of time exhibited normal proliferation and normal cell cycle progression. Our results show that SM and HG exert phenomenological distinct responses over cell cycle progression. The deficits of SM can be restored by terrestrial gravitational force, whereas the effects of HG are indistinguishable from the 1 g control. This suggests that the mechanotransduction apparatus of cells responds differently to mechanical unloading and loading. PMID:23974110

Cancer-associated variant expression and interaction of CIZ1 with cyclin A1 in differentiating male germ cells.

PubMed

Greaves, Erin A; Copeland, Nikki A; Coverley, Dawn; Ainscough, Justin F X

2012-05-15

CIZ1 is a nuclear-matrix-associated DNA replication factor unique to higher eukaryotes, for which alternatively spliced isoforms have been associated with a range of disorders. In vitro, the CIZ1 N-terminus interacts with cyclin E and cyclin A at distinct sites, enabling functional cooperation with cyclin-A-Cdk2 to promote replication initiation. C-terminal sequences anchor CIZ1 to fixed sites on the nuclear matrix, imposing spatial constraint on cyclin-dependent kinase activity. Here we demonstrate that CIZ1 is predominantly expressed as a predicted full-length product throughout mouse development, consistent with a ubiquitous role in cell and tissue renewal. CIZ1 is expressed in proliferating stem cells of the testis, but is notably downregulated following commitment to differentiation. Significantly, CIZ1 is re-expressed at high levels in non-proliferative spermatocytes before meiotic division. Sequence analysis identifies at least seven alternatively spliced variants, including a dominant cancer-associated form and a set of novel isoforms. Furthermore, we show that in these post-replicative cells, CIZ1 interacts with germ-cell-specific cyclin A1, which has been implicated in the repair of DNA double-strand breaks. Consistent with this role, antibody depletion of CIZ1 reduces the capacity for testis extract to repair digested plasmid DNA in vitro. Together, the data imply post-replicative roles for CIZ1 in germ cell differentiation that might include meiotic recombination - a process intrinsic to genome stability and diversification.

Prevention of Bronchial Hyperplasia by EGFR Pathway Inhibitors in an Organotypic Culture Model

PubMed Central

Lee, Jangsoon; Ryu, Seung-Hee; Kang, Shin Myung; Chung, Wen-Cheng; Gold, Kathryn Ann; Kim, Edward S.; Hittelman, Walter N.; Hong, Waun Ki; Koo, Ja Seok

2011-01-01

Lung cancer is the leading cause of cancer-related mortality worldwide. Early detection or prevention strategies are urgently needed to increase survival. Hyperplasia is the first morphologic change that occurs in the bronchial epithelium during lung cancer development, followed by squamous metaplasia, dysplasia, carcinoma in situ, and invasive tumor. The current study was designed to determine the molecular mechanisms that control bronchial epithelium hyperplasia. Using primary normal human tracheobronchial epithelial (NHTBE) cells cultured using the 3-dimensional organotypic method, we found that the epidermal growth factor receptor (EGFR) ligands EGF, transforming growth factor-alpha, and amphiregulin induced hyperplasia, as determined by cell proliferation and multilayered epithelium formation. We also found that EGF induced increased cyclin D1 expression, which plays a critical role in bronchial hyperplasia; this overexpression was mediated by activating the mitogen-activated protein kinase pathway but not the phosphoinositide 3-kinase/Akt signaling pathway. Erlotinib, an EGFR tyrosine kinase inhibitor, and U0126, a MEK inhibitor, completely inhibited EGF-induced hyperplasia. Furthermore, a promoter analysis revealed that the activator protein-1 transcription factor regulates EGF-induced cyclin D1 overexpression. Activator protein-1 depletion using siRNA targeting its c-Jun component completely abrogated EGF-induced cyclin D1 expression. In conclusion, we demonstrated that bronchial hyperplasia can be modeled in vitro using primary NHTBE cells maintained in a 3-dimensional (3-D) organotypic culture. EGFR and MEK inhibitors completely blocked EGF-induced bronchial hyperplasia, suggesting that they have a chemopreventive role. PMID:21505178

Stress and developmental regulation of the yeast C-type cyclin Ume3p (Srb11p/Ssn8p).

PubMed Central

Cooper, K F; Mallory, M J; Smith, J B; Strich, R

1997-01-01

The ume3-1 allele was identified as a mutation that allowed the aberrant expression of several meiotic genes (e.g. SPO11, SPO13) during mitotic cell division in Saccharomyces cerevisiae. Here we report that UME3 is also required for the full repression of the HSP70 family member SSA1. UME3 encodes a non-essential C-type cyclin (Ume3p) whose levels do not vary through the mitotic cell cycle. However, Ume3p is destroyed during meiosis or when cultures are subjected to heat shock. Ume3p mutants resistant to degradation resulted in a 2-fold reduction in SPO13 mRNA levels during meiosis, indicating that the down-regulation of this cyclin is important for normal meiotic gene expression. Mutational analysis identified two regions (PEST-rich and RXXL) that mediate Ume3p degradation. A third destruction signal lies within the highly conserved cyclin box, a region that mediates cyclin-cyclin-dependent kinase (Cdk) interactions. However, the Cdk activated by Ume3p (Ume5p) is not required for the rapid destruction of this cyclin. Finally, Ume3p destruction was not affected in mutants defective for ubiquitin-dependent proteolysis. These results support a model in which Ume3p, when exposed to heat shock or sporulation conditions, is targeted for destruction to allow the expression of genes necessary for the cell to respond correctly to these environmental cues. PMID:9303311

Pao Pereira Extract Suppresses Castration-Resistant Prostate Cancer Cell Growth, Survival, and Invasion Through Inhibition of NFκB Signaling.

PubMed

Chang, Cunjie; Zhao, Wei; Xie, Bingxian; Deng, Yongming; Han, Tao; Cui, Yangyan; Dai, Yundong; Zhang, Zhen; Gao, Jimin; Guo, Hongqian; Yan, Jun

2014-05-01

Pao extract, derived from bark of Amazonian tree Pao Pereira, is commonly used in South American medicine. A recent study showed that Pao extract repressed androgen-dependent LNCaP prostate cancer cell growth. We hypothesize that Pao extract asserts its anticancer effects on metastatic castration-resistant prostate cancer (CRPC) cells. Pao extract suppressed CRPC PC3 cell growth in a dose- and time-dependent manner, through induction of apoptosis and cell cycle arrest. Pao extract treatment induced cell cycle inhibitors, p21 and p27, and repressed PCNA, Cyclin A and Cyclin D1. Furthermore, Pao extract also induced the upregulation of pro-apoptotic Bax, reduction of anti-apoptotic Bcl-2, Bcl-xL, and XIAP expression, which were associated with the cleavage of PARP protein. Moreover, Pao extract treatment blocked PC3 cell migration and invasion. Mechanistically, Pao extract suppressed phosphorylation levels of AKT and NFκB/p65, NFκB DNA binding activity, and luciferase reporter activity. Pao inhibited TNFα-induced relocation of NFκB/p65 to the nucleus, NFκB/p65 transcription activity, and MMP9 activity as shown by zymography. Consistently, NFκB/p65 downstream targets involved in proliferation (Cyclin D1), survival (Bcl-2, Bcl-xL, and XIAP), and metastasis (VEGFa, MMP9, and GROα/CXCL1) were also downregulated by Pao extract. Finally, forced expression of NFκB/p65 reversed the growth inhibitory effect of Pao extract. Overall, Pao extract induced cell growth arrest, apoptosis, partially through inhibiting NFκB activation in prostate cancer cells. These data suggest that Pao extract may be beneficial for protection against CRPC. © The Author(s) 2013.

Hypothermia and Rewarming Induce Gene Expression and Multiplication of Cells in Healthy Rat Prostate Tissue

PubMed Central

Kaija, Helena; Pakanen, Lasse; Kortelainen, Marja-Leena; Porvari, Katja

2015-01-01

Prostate cancer has been extensively studied, but cellular stress responses in healthy prostate tissue are rarely investigated. Hypothermia is known to cause alterations in mRNA and protein expressions and stability. The aim of this study was to use normal rat prostate as a model in order to find out consequences of cold exposure and rewarming on the expressions of genes which are either members or functionally/structurally related to erythroblastic leukemia viral oncogene B (ErbB) signaling pathway. Relative mRNA expressions of amphiregulin (AMR), cyclin D1 (CyD1), cyclin-dependent kinase inhibitor 1A (p21), transmembrane form of the prostatic acid phosphatase (PAcP), thrombomodulin (TM) and heat shock transcription factor 1 (HSF1) in rat ventral prostate were quantified in mild (2 or 4.5 h at room temperature) and severe (2 or 4.5 h at +10°C) hypothermia and in rewarming after cold exposure (2 h at +10°C followed by 2 h at room temperature or 3 h at +28°C). AMR protein level, apoptotic Bcl-2 associated X protein to B-cell CLL/lymphoma 2 (Bax/Bcl-2) mRNA ratio and proliferative index Ki-67 were determined. 4.5-h mild hypothermia, 2-h severe hypothermia and rewarming increased expression of all these genes. Elevated proliferation index Ki-67 could be seen in 2-h severe hypothermia, and the proliferation index had its highest value in longer rewarming with totally recovered normal body temperature. Pro-apoptotic tendency could be seen in 2-h mild hypothermia while anti-apoptosis was predominant in 4.5-h mild hypothermia and in shorter rewarming with only partly recovered body temperature. Hypothermia and following rewarming promote the proliferation of cells in healthy rat prostate tissue possibly via ErbB signaling pathway. PMID:25996932

Disruption of the G1/S Transition in Human Papillomavirus Type 16 E7-Expressing Human Cells Is Associated with Altered Regulation of Cyclin E

PubMed Central

Martin, Larry G.; Demers, G. William; Galloway, Denise A.

1998-01-01

The development of neoplasia frequently involves inactivation of the p53 and retinoblastoma (Rb) tumor suppressor pathways and disruption of cell cycle checkpoints that monitor the integrity of replication and cell division. The human papillomavirus type 16 (HPV-16) oncoproteins, E6 and E7, have been shown to bind p53 and Rb, respectively. To further delineate the mechanisms by which E6 and E7 affect cell cycle control, we examined various aspects of the cell cycle machinery. The low-risk HPV-6 E6 and E7 proteins did not cause any significant change in the levels of cell cycle proteins analyzed. HPV-16 E6 resulted in very low levels of p53 and p21 and globally elevated cyclin-dependent kinase (CDK) activity. In contrast, HPV-16 E7 had a profound effect on several aspects of the cell cycle machinery. A number of cyclins and CDKs were elevated, and despite the elevation of the levels of at least two CDK inhibitors, p21 and p16, CDK activity was globally increased. Most strikingly, cyclin E expression was deregulated both transcriptionally and posttranscriptionally and persisted at high levels in S and G2/M. Transit through G1 was shortened by the premature activation of cyclin E-associated kinase activity. Elevation of cyclin E levels required both the CR1 and CR2 domains of E7. These data suggest that cyclin E may be a critical target of HPV-16 E7 in the disruption of G1/S cell cycle progression and that the ability of E7 to regulate cyclin E involves activities in addition to the release of E2F. PMID:9444990

[Long-term expansion of multipotent mesenchymal stromal cells under reduced oxygen tension].

PubMed

Rylova, Iu V; Buravkova, L B

2013-01-01

We have shown that the decrease in oxygen tension in the culture medium of multipotent mesenchymal stromal cells (MMSCs) results in a short-term reduction in the proportion of CD73(+)-cells in the population, without effecting the number of cells expressing other constitutive surface markers (CD90 and CD105). In this case, the heterogeneity of the cell population declined: large spread cells disappeared. The proliferative activity of MMSCs significantly increased and remained stable in conditions in which the oxygen content was close to the tissue oxygen levels (5% O2). At lower oxygen concentration, proliferative activity of the cells gradually reduced from passages 3-4. The increase in proliferative activity was not accompanied by increased expression of telomerase gene indicateding the alsance of cell transformation. However, genome-wide analysis of MMSC gene expression level revealed changes in expression of cyclins (CCND2 and PCNA), regulatory subunit cyclin-dependent kinase (CKS2) and an inhibitor of cyclin-dependent kinase (CDKN2C), regulating the cell cycle, which is obviously facilitated the increase in the proliferative capacity of cells at lower oxygen tension.

Resveratrol Suppresses Growth and Migration of Myelodysplastic Cells by Inhibiting the Expression of Elevated Cyclin D1 (CCND1).

PubMed

Zhou, Wei; Xu, Shilin; Ying, Yi; Zhou, Ruiqing; Chen, Xiaowei

2017-11-01

Myelodysplastic syndromes (MDS) are a group of heterogeneous diseases characterized by poorly formed blood cells. We wanted to elucidate the underlying molecular mechanism to better determine pathogenesis, prognosis, diagnosis, and treatment for patients with MDS. We compared gene expression levels between normal and MDS tissue samples by immunohistochemical analysis. We studied the proliferation, survival, and migration of MDS cells using the EDU assay, colony formation, and transwell assays. We assessed the apoptotic rate and cell cycle status using flow cytometry and Hoechst staining. Finally, we evaluated RNA and protein expressions using polymerase chain reaction and Western blots, respectively. We found that resveratrol suppressed SKM-1 (an advanced MDS cell line) proliferation in a dose-dependent manner. Consistent with this finding, the EDU and colony formation assays also showed that resveratrol inhibited SKM-1 growth. Moreover, flow cytometry and Hoechst 33258 staining demonstrated that resveratrol induced apoptosis and a change in cell cycle status in SKM-1 cells, while the transwell assay showed that resveratrol reduced the migratory ability of SKM-1 cells. Resveratrol also decreased the expression of CCND1 (a gene that encodes the cyclin D1 protein) and increased expressions of KMT2A [lysine (K)-specific methyltransferase 2A] and caspase-3, suggesting that resveratrol exerts its effect by regulating CCND1 in SKM-1 cells. In addition, a combination of resveratrol and the PI3K/AKT inhibitor LY294002 exhibited a stronger inhibitory effect on the SKM-1 cells, compared with resveratrol alone. Our study proved that resveratrol suppresses SKM-1 growth and migration by inhibiting CCND1 expression. This finding provides novel insights into the pathogenesis of MDS and might help develop new diagnosis and treatment for patients with MDS.

Argonaute-1 functions as a mitotic regulator by controlling Cyclin B during Drosophila early embryogenesis.

PubMed

Pushpavalli, Sreerangam N C V L; Sarkar, Arpita; Bag, Indira; Hunt, Clayton R; Ramaiah, M Janaki; Pandita, Tej K; Bhadra, Utpal; Pal-Bhadra, Manika

2014-02-01

The role of Ago-1 in microRNA (miRNA) biogenesis has been thoroughly studied, but little is known about its involvement in mitotic cell cycle progression. In this study, we established evidence of the regulatory role of Ago-1 in cell cycle control in association with the G2/M cyclin, cyclin B. Immunostaining of early embryos revealed that the maternal effect gene Ago-1 is essential for proper chromosome segregation, mitotic cell division, and spindle fiber assembly during early embryonic development. Ago-1 mutation resulted in the up-regulation of cyclin B-Cdk1 activity and down-regulation of p53, grp, mei-41, and wee1. The increased expression of cyclin B in Ago-1 mutants caused less stable microtubules and probably does not produce enough force to push the nuclei to the cortex, resulting in a decreased number of pole cells. The role of cyclin B in mitotic defects was further confirmed by suppressing the defects in the presence of one mutant copy of cyclin B. We identified involvement of 2 novel embryonic miRNAs--miR-981 and miR--317-for spatiotemporal regulation of cyclin B. In summary, our results demonstrate that the haploinsufficiency of maternal Ago-1 disrupts mitotic chromosome segregation and spindle fiber assembly via miRNA-guided control during early embryogenesis in Drosophila. The increased expression of cyclin B-Cdk1 and decreased activity of the Cdk1 inhibitor and cell cycle checkpoint proteins (mei-41 and grp) in Ago-1 mutant embryos allow the nuclei to enter into mitosis prematurely, even before completion of DNA replication. Thus, our results have established a novel role of Ago-1 as a regulator of the cell cycle.

Immunohistochemical study of cyclin A and p16 expression in patients with renal cell carcinoma.

PubMed

Latic, Dragana; Radojevic-Skodric, Sanja; Nikolic, Srdjan; Prvanovic, Mirjana; Lazic, Miodrag; Dzamic, Zoran; Bogdanovic, Ljiljana; Radunovic, Milena; Vukovic, Marina

2017-01-01

Renal cell carcinoma (RCC) is the most common malignant kidney tumor in adults. Dysregulation of the cell cycle can lead to cancer development. In this study, the mitosis-associated cyclin A and p16, a negative controller, were investigated as potential key points in the RCC development. This retrospective study included 74 patients with RCC. The expression of cyclin A and p16 and their correlation to histopathological parameters (TNM stage, histological subtype, nuclear grade, tumor size), gender, age, and clinical outcome were studied and analyzed. The highest median value for cyclin A (40%; range 0-70)) and for p16 (57.5%); range 35-80) were found in the papillary histological subtype. Survival analysis showed that in the group of patients that had died before September 2015, the median value for cyclin A was 20% (range 0-60), which was significantly higher than 5% (range 0-70), found in the group of patients that survived (p=0.019). In relation to the histological subtype, the papillary type of RCC was associated with a significantly higher expression of cyclin A and p16 compared to other subtypes of RCC. High expression of cyclin A indicated worse prognosis, therefore cyclin A could be considered to be a significant prognostic marker.

The soy-derived peptide Vglycin inhibits the growth of colon cancer cells in vitro and in vivo.

PubMed

Gao, Chang; Sun, Rui; Xie, Ya-Rong; Jiang, An-Li; Lin, Mei; Li, Min; Chen, Zheng-Wang; Zhang, Ping; Jin, Honglin; Feng, Jue-Ping

2017-05-01

Vglycin, a novel natural polypeptide isolated from pea seeds, possesses antidiabetic properties. Our previous studies have shown that Vglycin can induce the differentiation of human colon adenocarcinoma cells. We aimed to determine the anticancer activity of Vglycin against colon cancer cells and to elucidate related apoptosis-inducing mechanisms. Treatment with purified Vglycin significantly reduced growth, viability, and colony formation of CT-26, SW480, and NCL-H716 colon cancer cells in a dose-dependent manner while down-regulating the expression of proliferating cell nuclear antigen. Mouse xenograft studies showed a 38% inhibition of colon cancer growth in mice treated with Vglycin (20 mg/kg/day) at day 21. Furthermore, the potential mechanisms involved in Vglycin-induced cell apoptosis were examined using cell cycle studies, ultrastructural examination, as well as apoptosis-associated pathway analysis. The results showed that Vglycin significantly promoted apoptosis and G1/S phase cell cycle arrest. As revealed by Western blot, the expression of CDK2 and Cyclin D1 was down-regulated in all three Vglycin-treated colon cancer cells, indicating that the CDK2/Cyclin D1 cell cycle pathway involved in the initiation and progression of colon cancer. Moreover, the inhibition of Vglycin-induced cell proliferation in colon cancer cells was accompanied by alteration of the expression levels of the apoptosis-related proteins Bax, Bcl-2 and Mcl-1, and an increase of caspase-3 activity. Together, our results suggest that Vglycin may be another plant-derived peptide that suppresses colon cancer, supporting the continued investigation of Vglycin as therapeutic agent for colon cancer. Impact statement The antidiabetic properties and the capability of inducing differentiation of human colon adenocarcinoma cells of Vglycin have been reported in our previous studies. However, the anticancer potential of Vglycin on colon cancer cells and its possible related mechanisms were still unknown. In this study, we found that Vglycin could reduce growth, viability, and colony formation or colony size of CT-26, SW480, and NCL-H716 colon cancer cells. Moreover, Vglycin decreased tumor volume by 38% in xenograft mice transplanted with CT-26 cells. The mechanisms of these phenomena may be due to the down-regulated CDK2 and Cyclin D1, G1/S phase cell cycle arrest, and the dysregulated expression of Bax, Bcl-2, and Mcl-1. The findings highlight the anticancer potential of Vglycin against colon cancer cells, and suggest Vglycin may be another colon cancer potential suppressive component of plant-derived peptides.

Di(2-ethylhexyl) phthalate inhibits antral follicle growth, induces atresia, and inhibits steroid hormone production in cultured mouse antral follicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hannon, Patrick R., E-mail: phannon2@illinois.edu; Brannick, Katherine E., E-mail: kbran@illinois.edu; Wang, Wei, E-mail: Wei.Wang2@covance.com

Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental toxicant found in consumer products that causes ovarian toxicity. Antral follicles are the functional ovarian units and must undergo growth, survival from atresia, and proper regulation of steroidogenesis to ovulate and produce hormones. Previous studies have determined that DEHP inhibits antral follicle growth and decreases estradiol levels in vitro; however, the mechanism by which DEHP elicits these effects is unknown. The present study tested the hypothesis that DEHP directly alters regulators of the cell cycle, apoptosis, and steroidogenesis to inhibit antral follicle functionality. Antral follicles from adult CD-1 mice were cultured with vehiclemore » control or DEHP (1–100 μg/ml) for 24–96 h to establish the temporal effects of DEHP on the follicle. Following 24–96 h of culture, antral follicles were subjected to gene expression analysis, and media were subjected to measurements of hormone levels. DEHP increased the mRNA levels of cyclin D2, cyclin dependent kinase 4, cyclin E1, cyclin A2, and cyclin B1 and decreased the levels of cyclin-dependent kinase inhibitor 1A prior to growth inhibition. Additionally, DEHP increased the mRNA levels of BCL2-associated agonist of cell death, BCL2-associated X protein, BCL2-related ovarian killer protein, B-cell leukemia/lymphoma 2, and Bcl2-like 10, leading to an increase in atresia. Further, DEHP decreased the levels of progesterone, androstenedione, and testosterone prior to the decrease in estradiol levels, with decreased mRNA levels of side-chain cleavage, 17α-hydroxylase-17,20-desmolase, 17β-hydroxysteroid dehydrogenase, and aromatase. Collectively, DEHP directly alters antral follicle functionality by inhibiting growth, inducing atresia, and inhibiting steroidogenesis. - Highlights: • DEHP inhibits antral follicle growth by dysregulating cell cycle regulators. • DEHP induces antral follicle atresia by dysregulating apoptosis regulators. • DEHP inhibits the production of antral follicle produced sex steroid hormones.« less

Vitamin D receptor expression and potential role of vitamin D on cell proliferation and steroidogenesis in goat ovarian granulosa cells.

PubMed

Yao, Xiaolei; Zhang, Guomin; Guo, Yixuan; Ei-Samahy, Mohamed; Wang, Shuting; Wan, Yongjie; Han, Le; Liu, Zifei; Wang, Feng; Zhang, Yanli

2017-10-15

This study aimed to investigate the expression of the vitamin D receptor (VDR) in goat follicles and to determine the effects of Vit D 3 supplementation on goat granulosa cells (GCs) function linked to follicular development. The results demonstrated that VDR was prominently localized in GCs, with expression increasing with follicle diameter. Addition of Vit D 3 (1α,25-(OH) 2 VD 3 ; 10 nM) to GCs caused an increase in VDR and in steroidogenic acute regulator (StAR) and 3β-hydroxysteroid dehydrogenase (3β-HSD) mRNA expression. Additionally, Vit D 3 increased the cyclic adenosine monophosphate (cAMP), estradiol (E 2 ), and progesterone (P 4 ) levels, while it decreased anti-müllerian hormone receptor (AMHR) and follicle-stimulating hormone receptor (FSHR) mRNA expression (P < 0.05). Addition of FSH remarkably increased E 2, P 4 , and cAMP levels (P < 0.05), and Vit D 3 further enhanced the E 2 and cAMP levels in the presence of FSH (P < 0.05). Vit D 3 significantly induced the mRNA expression of CDK4 and CyclinD1, and downregulated P21 gene expression (P < 0.05). In addition, Vit D 3 significantly decreased reactive oxygen species (ROS) production and increased the mRNA and protein expression of superoxide dismutase 2 (SOD2) and catalase (CAT) (P < 0.05). In conclusion, VDR is expressed in GCs of the goat ovaries and Vit D 3 might play an important role in GCs proliferation by regulating cellular oxidative stress and cell cycle-related genes. Meanwhile, Vit D 3 enhances the E 2 and P 4 output of GCs by regulating the expression of 3β-HSD and StAR and the level of cAMP, which regulate steroidogenesis, supporting a potential role for Vit D 3 in follicular development. Copyright © 2017 Elsevier Inc. All rights reserved.

Inhibition of SAPK2/p38 enhances sensitivity to mTORC1 inhibition by blocking IRES-mediated translation initiation in glioblastoma.

PubMed

Cloninger, Cheri; Bernath, Andrew; Bashir, Tariq; Holmes, Brent; Artinian, Nicholas; Ruegg, Teresa; Anderson, Lauren; Masri, Janine; Lichtenstein, Alan; Gera, Joseph

2011-12-01

A variety of mechanisms confer hypersensitivity of tumor cells to the macrolide rapamycin, the prototypic mTORC1 inhibitor. Several studies have shown that the status of the AKT kinase plays a critical role in determining hypersensitivity. Cancer cells in which AKT activity is elevated are exquisitely sensitive to mTORC1 inhibitors while cells in which the kinase is quiescent are relatively resistant. Our previous work has shown that a transcript-specific protein synthesis salvage pathway is operative in cells with quiescent AKT levels, maintaining the translation of crucial mRNAs involved in cell-cycle progression in the face of global eIF-4E-mediated translation inhibition. The activation of this salvage pathway is dependent on SAPK2/p38-mediated activation of IRES-dependent initiation of the cyclin D1 and c-MYC mRNAs, resulting in the maintenance of their protein expression levels. Here, we show that both genetic and pharmacologic inhibition of SAPK2/p38 in glioblastoma multiforme cells significantly reduces rapamycin-induced IRES-mediated translation initiation of cyclin D1 and c-MYC, resulting in increased G(1) arrest in vitro and inhibition of tumor growth in xenografts. Moreover, we observed that the AKT-dependent signaling alterations seen in vitro are also displayed in engrafted tumors cells and were able to show that combined inhibitor treatments markedly reduced the mRNA translational state of cyclin D1 and c-MYC transcripts in tumors isolated from mice. These data support the combined use of SAPK2/p38 and mTORC1 inhibitors to achieve a synergistic antitumor therapeutic response, particularly in rapamycin-resistant quiescent AKT-containing cells.

Effects of Long-Term 50Hz Power-Line Frequency Electromagnetic Field on Cell Behavior in Balb/c 3T3 Cells

PubMed Central

An, Guang-Zhou; Xu, Hui; Zhou, Yan; Du, Le; Miao, Xia; Jiang, Da-Peng; Li, Kang-Chu; Guo, Guo-Zhen; Zhang, Chen; Ding, Gui-Rong

2015-01-01

Power-line frequency electromagnetic field (PF-EMF) was reported as a human carcinogen by some epidemiological research, but the conclusion is lack of robust experiment evidence. To identify the effects of long-term PF-EMF exposure on cell behavior, Balb/c 3T3 cells in exponential growth phase were exposed or sham-exposed to 50 Hertz (Hz) PF-EMF at 2.3 mT for 2 hours (h) one day, 5 days every week. After 11 weeks exposure, cells were collected instantly. Cell morphology was observed under invert microscope and Giemsa staining, cell viability was detected by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, cell cycle and apoptosis was examined by flow cytometry, the protein level of Proliferating Cell Nuclear Antigen (PCNA) and CyclinD1 was detected by western blot, cell transformation was examined by soft agar clone assay and plate clone forming test, and cell migration ability was observed by scratch adhesion test. It was found that after PF-EMF exposure, cell morphology, apoptosis, cell migration ability and cell transformation didn’t change. However, compared with sham group, cell viability obviously decreased and cell cycle distribution also changed after 11 weeks PF-EMF exposure. Meanwhile, the protein level of PCNA and CyclinD1 significantly decreased after PF-EMF exposure. These data suggested that although long-term 50Hz PF-EMF exposure under this experimental condition had no effects on apoptosis, cell migration ability and cell transformation, it could affect cell proliferation and cell cycle by down-regulation the expression of PCNA and CyclinD1 protein. PMID:25695503

Effects of long-term 50Hz power-line frequency electromagnetic field on cell behavior in Balb/c 3T3 cells.

PubMed

An, Guang-Zhou; Xu, Hui; Zhou, Yan; Du, Le; Miao, Xia; Jiang, Da-Peng; Li, Kang-Chu; Guo, Guo-Zhen; Zhang, Chen; Ding, Gui-Rong

2015-01-01

Power-line frequency electromagnetic field (PF-EMF) was reported as a human carcinogen by some epidemiological research, but the conclusion is lack of robust experiment evidence. To identify the effects of long-term PF-EMF exposure on cell behavior, Balb/c 3T3 cells in exponential growth phase were exposed or sham-exposed to 50 Hertz (Hz) PF-EMF at 2.3 mT for 2 hours (h) one day, 5 days every week. After 11 weeks exposure, cells were collected instantly. Cell morphology was observed under invert microscope and Giemsa staining, cell viability was detected by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, cell cycle and apoptosis was examined by flow cytometry, the protein level of Proliferating Cell Nuclear Antigen (PCNA) and CyclinD1 was detected by western blot, cell transformation was examined by soft agar clone assay and plate clone forming test, and cell migration ability was observed by scratch adhesion test. It was found that after PF-EMF exposure, cell morphology, apoptosis, cell migration ability and cell transformation didn't change. However, compared with sham group, cell viability obviously decreased and cell cycle distribution also changed after 11 weeks PF-EMF exposure. Meanwhile, the protein level of PCNA and CyclinD1 significantly decreased after PF-EMF exposure. These data suggested that although long-term 50Hz PF-EMF exposure under this experimental condition had no effects on apoptosis, cell migration ability and cell transformation, it could affect cell proliferation and cell cycle by down-regulation the expression of PCNA and CyclinD1 protein.

Dietary calcium and cholecalciferol modulate cyclin D1 expression, apoptosis, and tumorigenesis in intestine of adenomatous polyposis coli1638N/+ mice.

PubMed

Yang, Kan; Lamprecht, Sergio A; Shinozaki, Hiroharu; Fan, Kunhua; Yang, Wancai; Newmark, Harold L; Kopelovich, Levy; Edelmann, Winfried; Jin, Bo; Gravaghi, Claudia; Augenlicht, Leonard; Kucherlapati, Raju; Lipkin, Martin

2008-09-01

Both epidemiological and experimental findings have indicated that components of Western diets influence colonic tumorigenesis. Among dietary constituents, calcium and cholecalciferol have emerged as promising chemopreventive agents. We have demonstrated that a Western-style diet (WD) with low levels of calcium and cholecalciferol and high levels of (n-6) PUFA, increased the incidence of neoplasia in mouse intestine compared with a standard AIN-76A diet; models included wild-type mice and mice with targeted mutations. In the present study, adenomatous polyposis coli (Apc)(1638N/+) mice carrying a heterozygous Apc mutation were fed either an AIN-76A diet, a WD, or a WD supplemented with calcium and cholecalciferol (WD/Ca/VitD3). Diets were fed for 24 wk and effects on cellular and molecular events were assessed by performing immunohistochemistry in colonic epithelium along the crypt-to-surface continuum. Feeding WD to Apc(1638N/+) mice not only enhanced cyclin D1 expression in colonic epithelium compared with AIN-76A treatment as previously reported but also significantly increased the expression of the antiapoptotic protein B-cell lymphoma 2 (Bcl-2) concomitantly with a decrease in the proapoptotic Bcl2-associated X protein and the number of apoptotic epithelial cells. WD treatment enhanced mutant Apc-driven small intestinal carcinogenesis and also resulted in the formation of a small number of colonic adenomas (0.16 +/- 0.09; P < 0.05). By contrast, the WD/Ca/VitD3 diet reversed WD-induced growth, promoting changes in colonic epithelium. Importantly, Apc(1638N/+) mice fed the WD/Ca/VitD3 diet did not develop colonic tumors, further indicating that dietary calcium and cholecalciferol have a key role in the chemoprevention of colorectal neoplasia in this mouse model of human colon cancer.

Dixdc1 targets CyclinD1 and p21 via PI3K pathway activation to promote Schwann cell proliferation after sciatic nerve crush

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Weijie; Liu, Qingqing; Liu, Yuxi

Dixdc1 (DIX domain containing-1), the mammalian homolog of Ccd1 (Coiled-coil-Dishevelled-Axin1), is a protein containing a coiled-coil domain and a Dishevelled-Axin (DIX) domain. As a novel component of the Wnt pathway, Dixdc1 has been reported to be able to promote neural progenitor proliferation and neuronal differentiation via Wnt/β-catenin signaling. But there still remains something unknown about Dixdc1 distribution and functions in the lesion and regeneration of the peripheral nervous system (PNS), so we tried to investigate dynamic changes of Dixdc1 expression in a rat sciatic nerve crush (SNC) model in this study. First of all, we detected SNC-induced increased levels ofmore » Dixdc1 in Schwann cells and interestingly identified parallel expression of PCNA (proliferation cell nuclear antigen) with Dixdc1. Besides, we observed up-regulated Dixdc1 during the process of TNF-α-induced Schwann cell proliferation. Also, we discovered that Dixdc1 could promote G1-S phase transition accompanied with the up-regulation of CyclinD1 and down-regulation of p21. More importantly, enhanced effects of Dixdc1 on cell proliferation were confirmed to be associated with PI3K activation. Not only blocking of the PI3K but Dixdc1 knockdown led to significantly decreased ability for proliferation, as well as down-regulation of CyclinD1 and up-regulation of p21. In summary, these data demonstrated that Dixdc1 might participate in Schwann cell proliferation by targeting CyclinD1 and p21 at least partially through the PI3K/AKT activation. - Highlights: • The dynamic changes and location of Dixdc1 after sciatic nerve crush. • Dixdc1 was associated with Schwann cell proliferation. • Dixdc1 promoted Schwann cell proliferation partly via PI3K/AKT pathway.« less

Two inhibitory systems and CKIs regulate cell cycle exit of mammalian cardiomyocytes after birth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tane, Shoji; Okayama, Hitomi; Ikenishi, Aiko

Mammalian cardiomyocytes actively proliferate during embryonic stages, following which they exit their cell cycle after birth, and the exit is maintained. Previously, we showed that two inhibitory systems (the G1-phase inhibitory system: repression of cyclin D1 expression; the M-phase inhibitory system: inhibition of CDK1 activation) maintain the cell cycle exit of mouse adult cardiomyocytes. We also showed that two CDK inhibitors (CKIs), p21{sup Cip1} and p27{sup Kip1}, regulate the cell cycle exit in a portion of postnatal cardiomyocytes. It remains unknown whether the two inhibitory systems are involved in the cell cycle exit of postnatal cardiomyocytes and whether p21{sup Cip1}more » and p27{sup Kip1} also inhibit entry to M-phase. Here, we showed that more than 40% of cardiomyocytes entered an additional cell cycle by induction of cyclin D1 expression at postnatal stages, but M-phase entry was inhibited in the majority of cardiomyocytes. Marked cell cycle progression and endoreplication were observed in cardiomyocytes of p21{sup Cip1} knockout mice at 4 weeks of age. In addition, tri- and tetranucleated cardiomyocytes increased significantly in p21{sup Cip1} knockout mice. These data showed that the G1-phase inhibitory system and two CKIs (p21{sup Cip1} and p27{sup Kip1}) inhibit entry to an additional cell cycle in postnatal cardiomyocytes, and that the M-phase inhibitory system and p21{sup Cip1} inhibit M-phase entry of cardiomyocytes which have entered the additional cell cycle. - Highlights: • Many postnatal cardiomyocytes entered an additional cell cycle by cyclin D1 induction. • The majority of cardiomyocytes could not enter M-phase after cyclin D1 induction. • Cell cycle progressed markedly in p21{sup Cip1} knockout mice after postnatal day 14. • Tri- and tetranucleated cardiomyocytes increased in p21{sup Cip1} knockout mice.« less

miR-379 Regulates Cyclin B1 Expression and Is Decreased in Breast Cancer

PubMed Central

Khan, Sonja; Brougham, Cathy L.; Ryan, James; Sahrudin, Arisha; O’Neill, Gregory; Wall, Deirdre; Curran, Catherine; Newell, John; Kerin, Michael J.; Dwyer, Roisin M.

2013-01-01

MicroRNAs are small non-coding RNA molecules that control gene expression post-transcriptionally, and are known to be altered in many diseases including breast cancer. The aim of this study was to determine the relevance of miR-379 in breast cancer. miR-379 expression was quantified in clinical samples including tissues from breast cancer patients (n=103), healthy controls (n=30) and patients with benign breast disease (n=35). The level of miR-379 and its putative target Cyclin B1 were investigated on all breast tissue specimens by RQ-PCR. Potential relationships with gene expression and patient clinicopathological details were also determined. The effect of miR-379 on Cyclin B1 protein expression and function was investigated using western blot, immunohistochemistry and proliferation assays respectively. Finally, the levels of circulating miR-379 were determined in whole blood from patients with breast cancer (n=40) and healthy controls (n=34). The level of miR-379 expression was significantly decreased in breast cancer (Mean(SEM) 1.9 (0.09) Log10 Relative Quantity (RQ)) compared to normal breast tissues (2.6 (0.16) Log10 RQ, p<0.01). miR-379 was also found to decrease significantly with increasing tumour stage. A significant negative correlation was determined between miR-379 and Cyclin B1 (r=-0.31, p<0.001). Functional assays revealed reduced proliferation (p<0.05) and decreased Cyclin B1 protein levels following transfection of breast cancer cells with miR-379. Circulating miR-379 was not significantly dysregulated in patients with breast cancer compared to healthy controls (p=0.42). This data presents miR-379 as a novel regulator of Cyclin B1 expression, with significant loss of the miRNA observed in breast tumours. PMID:23874748

The Role of Polycomb Group Gene BMI-1 in the Development of Prostate Cancer

DTIC Science & Technology

2013-07-01

cyclin D1 (Wnt target) and Bcl-2 (Sonic Hedgehog -SHH target). The novel finding in presented in the 2nd annual report was that regulation of Bcl-2... hedgehog (SHH) pathway that is very well know to regulate Bcl-2. For this purpose we determined the expression level of Bcl-2 in BMI1- overexpressing and...2006; 15: 217-27. 16. Hegde GV, Munger CM, Emanuel K, Joshi AD, Greiner TC, Weisenburger DD, Vose JM, et al. Targeting of sonic hedgehog -GLI signaling

Identification of cyclin B1 and Sec62 as biomarkers for recurrence in patients with HBV-related hepatocellular carcinoma after surgical resection.

PubMed

Weng, Li; Du, Juan; Zhou, Qinghui; Cheng, Binbin; Li, Jun; Zhang, Denghai; Ling, Changquan

2012-06-08

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. Frequent tumor recurrence after surgery is related to its poor prognosis. Although gene expression signatures have been associated with outcome, the molecular basis of HCC recurrence is not fully understood, and there is no method to predict recurrence using peripheral blood mononuclear cells (PBMCs), which can be easily obtained for recurrence prediction in the clinical setting. According to the microarray analysis results, we constructed a co-expression network using the k-core algorithm to determine which genes play pivotal roles in the recurrence of HCC associated with the hepatitis B virus (HBV) infection. Furthermore, we evaluated the mRNA and protein expressions in the PBMCs from 80 patients with or without recurrence and 30 healthy subjects. The stability of the signatures was determined in HCC tissues from the same 80 patients. Data analysis included ROC analysis, correlation analysis, log-lank tests, and Cox modeling to identify independent predictors of tumor recurrence. The tumor-associated proteins cyclin B1, Sec62, and Birc3 were highly expressed in a subset of samples of recurrent HCC; cyclin B1, Sec62, and Birc3 positivity was observed in 80%, 65.7%, and 54.2% of the samples, respectively. The Kaplan-Meier analysis revealed that high expression levels of these proteins was associated with significantly reduced recurrence-free survival. Cox proportional hazards model analysis revealed that cyclin B1 (hazard ratio [HR], 4.762; p = 0.002) and Sec62 (HR, 2.674; p = 0.018) were independent predictors of HCC recurrence. These results revealed that cyclin B1 and Sec62 may be candidate biomarkers and potential therapeutic targets for HBV-related HCC recurrence after surgery.

Magnolol suppresses the proliferation and invasion of cholangiocarcinoma cells via inhibiting the NF-κB signaling pathway.

PubMed

Zhang, Fu-Hui; Ren, Hong-Yue; Shen, Jin-Xing; Zhang, Xiao-Yun; Ye, Hui-Ming; Shen, Dong-Yan

2017-10-01

Magnolol has shown the potential anticancer properties against a variety of cancers. However, the role of magnolol in cholangiocarcinoma (CCA) cells is unknown. In this study, we assessed the effect of magnolol on the CCA cells. CCA cells were treated with magnolol in the absence or presence of TNFα, the activator for NF-κB. After co-incubation with magnolol, cell proliferation and growth were examined by MTT, colony formation and xenograft tumors; cell cycle was analyzed by flow cytometry; cell migration and invasion were detected by wound healing and transwell assays; the expression of PCNA, Ki67, CyclinD1, MMP-2, MMP-7 and MMP-9 and NF-κB pathway were evaluated by using Western blot. Magnolol inhibited the abilities of CCA cell growth, migration and invasion accompanying with a decreased expression of PCNA, Ki67, MMP-2, MMP-7 and MMP-9 (all P<0.05). with magnolol induced cell cycle arrest in G1 phase with a downregulation of cell cycle protein CyclinD1 (all P<0.05). In addition, magnolol suppressed the expression of p-IκBα and p-P65 and the effect of magnolol on CCA cells could be inhibited by TNFα. Magnolol could inhibit the growth, migration and invasion of CCA cells through regulation of NF-κB pathway, and these data indicate that magnolol is a potential candidate for treating of CCA. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

[1-9-NαC]-crourorb A1 isolated from Croton urucurana latex induces G2/M cell cycle arrest and apoptosis in human hepatocarcinoma cells.

PubMed

de Matos Cândido-Bacani, Priscila; Ezan, Frédéric; de Oliveira Figueiredo, Patrícia; Matos, Maria de Fátima Cepa; Rodrigues Garcez, Fernanda; Silva Garcez, Walmir; Baffet, Georges

2017-05-05

[1-9-NαC]-crourorb A1 is a cyclic peptide isolated from Croton urucurana Baillon latex, found in midwestern Brazil, that has been shown to exert cytotoxic effects against a panel of cancer cell lines. However, the underlying mechanisms responsible for the crourorb A1-induced cytotoxicity in cancer cells remain unknown. In this study, the effects of crourorb A1 on the viability, apoptosis, cell cycle and migration of Huh-7 (human hepatocarcinoma) cells were investigated. We evaluated the viability of Huh-7 cells treated with crourorb A1 in 2D and 3D collagen cultures and found that cells in 3D culture exhibited increased resistance to crourorb A1 compared to cells in 2D culture (IC 50 : 62μg/ml versus 35.75μg/ml). Crourorb A1 treatment decreases the viability of Huh-7 cells in a dose- and time-dependent manner and is associated with the induction of apoptosis, in the absence of necrotic cells, through the activation of caspase-3/7 and increased expression of the pro-apoptotic proteins Bak, Bid, Bax, Puma, Bim, and Bad. The effects of crourorb A1 are also associated with G2/M phase cell cycle arrest and increases in cyclin-dependent kinase (CDK1) and cyclin B1 expression. A significant reduction in Huh-7 cell migration induced by crourorb A1 was also observed in the presence of mitomycin C. Finally, we showed that the JNK/MAP pathway, but not ERK signaling, is involved in crourorb A1-induced hepatocarcinoma cell mortality. Copyright © 2017 Elsevier B.V. All rights reserved.

GLI2 expression levels in radical nephrectomy specimens as a predictor of disease progression in patients with metastatic clear cell renal cell carcinoma following treatment with sunitinib

PubMed Central

Furukawa, Junya; Miyake, Hideaki; Fujisawa, Masato

2016-01-01

The aim of the present study was to investigate the role of the Hedgehog signaling pathway in the progression of metastatic clear cell renal cell carcinoma (m-ccRCC) as well as the molecular targets of sunitinib, an inhibitor of multiple tyrosine kinases. A total of 39 patients subjected to radical nephrectomy who were diagnosed with m-ccRCC and were subsequently treated with sunitinib were enrolled in the present study. The expression levels of the Hedgehog signaling proteins (GLI1, GLI2, cyclin D1, cyclin E and transforming growth factor-β) and major molecular targets of sunitinib [vascular endothelial growth factor receptor (VEGFR)-1 and −2, and platelet-derived growth factor receptor-α and -β] in primary RCC specimens were assessed by immunohistochemical staining. The expression levels of GLI2, VEGFR-1, VEGFR-2 and pre-treatment C-reactive protein as well as the Memorial Sloan-Kettering Cancer Center risk were identified as significant predictors of progression-free survival (PFS). Of these, only GLI2 expression was independently correlated to PFS according to multivariate analysis. Furthermore, treatment with sunitinib resulted in a marked inhibition of GLI2 expression in the parental human RCC ACHN cell line, but not in ACHN cells with acquired resistance to sunitinib. These findings suggested that GLI2 may be involved in the acquisition of resistance to sunitinib in RCC; thus, it may be useful to consider the expression levels of GLI2 in addition to conventional prognostic parameters when selecting m-ccRCC patients likely to benefit from treatment with sunitinib. PMID:27602218

Gene structure, expression, and DNA methylation characteristics of sea cucumber cyclin B gene during aestivation.

PubMed

Zhu, Aijun; Chen, Muyan; Zhang, Xiumei; Storey, Kenneth B

2016-12-05

The sea cucumber, Apostichopus japonicus, is a good model for studying environmentally-induced aestivation by a marine invertebrate. One of the central requirements of aestivation is the repression of energy-expensive cellular processes such as cell cycle progression. The present study identified the gene structure of the cell cycle regulator, cyclin B, and detected the expression levels of this gene over three stages of the annual aestivation-arousal cycle. Furthermore, the DNA methylation characteristics of cyclin B were analyzed in non-aestivation and deep-aestivation stages of sea cucumbers. We found that the cyclin B promoter contains a CpG island, three CCAAT-boxes and three cell cycle gene homology regions (CHRs). Application of qRT-PCR analysis showed significant downregulation of cyclin B transcript levels during deep-aestivation in comparison with non-aestivation in both intestine and longitudinal muscle, and these returned to basal levels after arousal from aestivation. Methylation analysis of the cyclin B core promoter revealed that its methylation level showed significant differences between non-aestivation and deep-aestivation stages (p<0.05) and interestingly, a positive correlation between Cyclin B transcripts expression and methylation levels of the core promoter was also observed. Our findings suggest that cell cycle progression may be reversibly arrested during aestivation as indicated by the changes in cyclin B expression levels and we propose that DNA methylation is one of the regulatory mechanisms involved in cyclin B transcriptional variation. Copyright © 2016 Elsevier B.V. All rights reserved.

Activation of IRE1α-XBP1 pathway induces cell proliferation and invasion in colorectal carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin, Chun; Jin, Zhao; Chen, Nian-zhao

2016-01-29

Cell proliferation and tumor metastasis are considered as the main reasons for death in colorectal carcinoma (CRC). IRE1α-XBP1 pathway is the most conserved UPR pathways, which are activated during ER stress caused by the accumulation of unfolded or misfolded protein in the lumen of ER. Here, we demonstrated the critical role of IRE1α-XBP1 pathway and underlying molecular mechanism in cell proliferation and tumor metastasis in CRC. By the use of tissue microarray analysis of samples from 119 patients with CRC, IRE1α was determined to be an independent predictor of overall survival as higher expression of IRE1α in CRC patients showedmore » lower survival rates (p = 0.0041). RNA interference and ectopic expression of IRE1α were applied to determine the molecular effects of IRE1α in CRC cells. The silencing of IRE1α inhibited the proliferation and blocked the invasion of CRC cells in vitro, while ectopic expression of IRE1α in turn promoted cell proliferation and invasion. IRE1α-XBP1 pathway regulated the mitosis of CRC cells through the directly binding of XBP1s to Cyclin D1 promoter to activate Cyclin D1 expression. Our results reveal that IRE1α-XBP1 pathway plays an important role in tumor progression and epithelial-to-mesenchymal transition (EMT), and IRE1α could be employed as a novel prognostic marker and a promising therapeutic target for CRC. - Highlights: • IRE1 was determined to be an independent predictor of overall survival in CRC patient. • IRE1-XBP1 pathway promoted CRC cell proliferation through regulating Cyclin D1 expression. • IRE1-XBP1 pathway played important role in EMT of CRC cells.« less

Hypermethylation of AP-2Alpha as a Prognostic Marker for DCIS

DTIC Science & Technology

2008-05-01

Unfortunately, among the methylation status of the AP2, CYCLIN D, ECAD , GSTP, and SSOCS genes, either as individual genes, or in combinations, no...0.61 to 4.10) 1.00 (referent) 0.35 ECAD M UM 0 100 3 97 GSTP M UM 40 60 24 76 2.02 (0.72 to 5.64) 1.00...Missing data: 1.4% for AP2, CYCLIN D, ECAD , GSTP; 4.2% for SSOCS; 2.8% for nuclear grade. §M=methylated; UM=unmethylated; +Two-sided

c-Myc plays a key role in TADs-induced apoptosis and cell cycle arrest in human hepatocellular carcinoma cells

PubMed Central

Zhang, Dongdong; Qi, Junpeng; Liu, Rui; Dai, Bingling; Ma, Weina; Zhan, Yingzhuan; Zhang, Yanmin

2015-01-01

Cancer cell growth is complicated progression which is regulated and controlled by multiple factors including cell cycle, migration and apoptosis. In present study, we report that TADs, a novel derivative of taspine, has an essential role in resisting hepatocellular carcinoma growth (including arrest cell cycle) and migration, and inducing cell apoptosis. Our findings demonstrated that the TADs showed good inhibition on the hepatoma cell growth and migration, and good action on apoptosis induction. Using genome-wide microarray analysis, we found the down-regulated growth and apoptosis factors, and selected down-regulated genes were confirmed by Western blot. Knockdown of a checkpoint c-Myc by siRNA significantly attenuated tumor inhibition and apoptosis effects of TADs. Moreover, our results indicated TADs could simultaneously increase cyclin D1 protein levels and decrease amount of cyclin E, cyclin B1 and cdc2 of the cycle proteins, and also TADs reduced Bcl-2 expression, and upregulated Bad, Bak and Bax activities. In conclusion, these results illustrated that TADs is a key factor in growth and apoptosis signaling inhibitor, has potential in cancer therapy. PMID:26045987

Nuclear alternate estrogen receptor GPR30 mediates 17beta-estradiol-induced gene expression and migration in breast cancer-associated fibroblasts.

PubMed

Madeo, Antonio; Maggiolini, Marcello

2010-07-15

Fibroblasts are the principal cellular component of connective tissue and are associated with cancer cells at all stages of tumor progression. Structural and functional contributions of fibroblasts to the growth, survival, and invasive capacity of cancer cells are beginning to emerge. In breast carcinoma, approximately 80% of stromal fibroblasts termed cancer-associated fibroblasts (CAF) are thought to manifest an activated phenotype that promotes cancer cell proliferation tumor growth at metastatic sites similar to the primary tumor. In this report, we show that CAFs respond to physiologic concentrations of 17beta-estradiol (E2) by rapidly inducing extracellular signal-regulated kinase phosphorylation and immediate early gene expression, including c-fos and connective tissue growth factor, and cyclin D1. Notably, the E2 response is mediated by the alternate estrogen receptor GPR30, which interfaces with the epidermal growth factor receptor (EGFR) signaling pathway. In particular, E2 stimulates a physical interaction between GPR30 and phosphorylated EGFR, recruiting them to the cyclin D1 gene promoter. Nuclear localization induced by E2 was confirmed by cellular immunofluorescence methods. GPR30 was required for CAF proliferation and migration induced by E2. Our results provide important new mechanistic insights into how CAFs are stimulated by estrogen through a GPR30-mediated nuclear signaling pathway. More generally, they define estrogenic GPR30 signaling as a functionally important component of the tumor microenvironment. (c)2010 AACR.

EMODIN DOWNREGULATES CELL PROLIFERATION MARKERS DURING DMBA INDUCED ORAL CARCINOGENESIS IN GOLDEN SYRIAN HAMSTERS.

PubMed

Manimaran, Asokan; Buddhan, Rajamanickam; Manoharan, Shanmugam

2017-01-01

Cell-cycle disruption is the major characteristic features of neoplastic transformation and the status of cell-cycle regulators can thus be utilized to assess the prognostic significance in patients with cancer. The PCNA, cyclin D1, CDK4, CDK6 and survivin expression in the buccal mucosa was utilized to evaluate the Emodin efficacy on abnormal cell proliferation during 7,12-dimethylbenz(a)anthracene (DMBA) induced oral carcinogenesis in golden Syrian hamsters. Topical application of DMBA, three times a week for 14 weeks, on the hamsters' buccal pouches developed well differentiated squamous cell carcinoma. Cyclin D1 and PCNA over-expression and up-regulation of CDK4, CDK6 and survivin were noticed in the buccal mucosa of hamsters treated with DMBA alone. Emodin administration (50mg/kg b.w) orally to hamsters treated with DMBA down-regulated the expression of cell proliferation markers in the buccal mucosa. The anti-cell proliferative role of Emodin is owing to its modulating efficacy on cell-cycle markers towards the tumor suppression during DMBA induced oral carcinogenesis.

Lovastatin inhibits proliferation of anaplastic thyroid cancer cells through up-regulation of p27 by interfering with the Rho/ROCK-mediated pathway.

PubMed

Zhong, Wen-Bin; Hsu, Sung-Po; Ho, Pei-Yin; Liang, Yu-Chih; Chang, Tien-Chun; Lee, Wen-Sen

2011-12-01

Previously, we demonstrated that lovastatin, a HMG-CoA reductase inhibitor, induced apoptosis, differentiation, and inhibition of invasiveness of human anaplastic thyroid carcinoma cells (ATCs). Here, we further examined the effect of lovastatin on the growth of ARO cells. Lovastatin (0-20μM) concentration-dependently decreased cell number in cultured ATC and arrested the cell at the G0/G1 phase of the cell cycle. Western blot analysis revealed that lovastatin caused an increase of the protein level of p27 and cyclin-dependent kinase (CDK)4 and a decrease of the protein level of cyclin A2, cyclin D3, and phosphorylated Rb (pRb), but did not significantly change the protein levels of p21, cyclins D1 and E, and CDK2, in ARO cells. The formation of the CDK2-p27 complex was increased and the CDK2 activity was decreased in the lovastatin-treated ARO cells. Pretreatment of ARO cells with a p27, but not p21, antisense oligonucleotide prevented the lovastatin-induced G0/G1 arrest in ARO cells. The lovastatin-induced growth inhibition and translocation of RhoA and Rac1 in ARO cells were completely prevented by mevalonate and partially by geranylgeranyl pyrophosphate. Treatment of ARO cells with Y27632, an inhibitor of Rho-associated kinase, abolished the GGPP-mediated prevention of lovastatin-induced anti-proliferation and up-regulation and prolonged degradation of p27. Taken together, these data suggest that lovastatin treatment caused a reduction of Rho geranylgeranylation, which in turn increased the expression and stability of p27, and then inhibited ARO cell proliferation. These data suggest that lovastatin merits further investigation as multipotent therapy for treatment ATC. Copyright © 2011 Elsevier Inc. All rights reserved.

Arsenic trioxide-mediated growth inhibition in gallbladder carcinoma cells via down-regulation of Cyclin D1 transcription mediated by Sp1 transcription factor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ai, Zhilong; Lu, Weiqi; Ton, Saixiong

2007-08-31

Gallbladder carcinoma (GBC), an aggressive and mostly lethal malignancy, is known to be resistant to a number of drug stimuli. Here, we demonstrated that arsenic trioxide inhibited the proliferation of gallbladder carcinoma in vivo and in vitro as well as the transcription of cell cycle-related protein Cyclin D1. And, Cyclin D1 overexpression inhibited the negative role of arsenic trioxide in cell cycle progression. We further explored the mechanisms by which arsenic trioxide affected Cyclin D1 transcription and found that the Sp1 transcription factor was down-regulated by arsenic trioxide, with a corresponding decrease in Cyclin D1 promoter activity. Taken together, thesemore » results suggested that arsenic trioxide inhibited gallbladder carcinoma cell proliferation via down-regulation of Cyclin D1 transcription in a Sp1-dependent manner, which provided a new mechanism of arsenic trioxide-involved cell proliferation and may have important therapeutic implications in gallbladder carcinoma patients.« less

Berberine Induces Cell Cycle Arrest in Cholangiocarcinoma Cell Lines via Inhibition of NF-κB and STAT3 Pathways.

PubMed

Puthdee, Nattapong; Seubwai, Wunchana; Vaeteewoottacharn, Kulthida; Boonmars, Thidarut; Cha'on, Ubon; Phoomak, Chatchai; Wongkham, Sopit

2017-01-01

Berberine is a natural compound found in several herbs. Anticancer activity of berberine was reported in several cancers, however, little is known regarding the effects of berberine against cholangiocarcinoma (CCA). In this study, the growth inhibitory effects of berberine on CCA cell lines and its molecular mechanisms were explored. Cell growth and cell cycle distribution were examined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. The expression levels of cell cycle regulatory proteins were determined by Western blot analysis. Berberine significantly inhibited growth of CCA cell lines in a dose and time dependent fashion. The inhibition was largely attributed to cell cycle arrest at the G1 phase through the reduction of cyclin D1, and cyclin E. Moreover, berberine could reduce the expression and activation of signal transducers and activator of transcription 3 (STAT3) and probably nuclear factor-kappaB (NF-κB) via suppression of extracellular signal-regulated kinase (ERK) 1/2 action. These results highlight the potential of berberine to be a multi-target agent for CCA treatment.

Comprehensive phenotypic analysis of knockout mice deficient in cyclin G1 and cyclin G2

PubMed Central

Ohno, Shouichi; Ikeda, Jun-ichiro; Naito, Yoko; Okuzaki, Daisuke; Sasakura, Towa; Fukushima, Kohshiro; Nishikawa, Yukihiro; Ota, Kaori; Kato, Yorika; Wang, Mian; Torigata, Kosuke; Kasama, Takashi; Uchihashi, Toshihiro; Miura, Daisaku; Yabuta, Norikazu; Morii, Eiichi; Nojima, Hiroshi

2016-01-01

Cyclin G1 (CycG1) and Cyclin G2 (CycG2) play similar roles during the DNA damage response (DDR), but their detailed roles remain elusive. To investigate their distinct roles, we generated knockout mice deficient in CycG1 (G1KO) or CycG2 (G2KO), as well as double knockout mice (DKO) deficient in both proteins. All knockouts developed normally and were fertile. Generation of mouse embryonic fibroblasts (MEFs) from these mice revealed that G2KO MEFs, but not G1KO or DKO MEFs, were resistant to DNA damage insults caused by camptothecin and ionizing radiation (IR) and underwent cell cycle arrest. CycG2, but not CycG1, co-localized with γH2AX foci in the nucleus after γ-IR, and γH2AX-mediated DNA repair and dephosphorylation of CHK2 were delayed in G2KO MEFs. H2AX associated with CycG1, CycG2, and protein phosphatase 2A (PP2A), suggesting that γH2AX affects the function of PP2A via direct interaction with its B’γ subunit. Furthermore, expression of CycG2, but not CycG1, was abnormal in various cancer cell lines. Kaplan–Meier curves based on TCGA data disclosed that head and neck cancer patients with reduced CycG2 expression have poorer clinical prognoses. Taken together, our data suggest that reduced CycG2 expression could be useful as a novel prognostic marker of cancer. PMID:27982046

The Rts1 Regulatory Subunit of Protein Phosphatase 2A Is Required for Control of G1 Cyclin Transcription and Nutrient Modulation of Cell Size

PubMed Central

Artiles, Karen; Anastasia, Stephanie; McCusker, Derek; Kellogg, Douglas R.

2009-01-01

The key molecular event that marks entry into the cell cycle is transcription of G1 cyclins, which bind and activate cyclin-dependent kinases. In yeast cells, initiation of G1 cyclin transcription is linked to achievement of a critical cell size, which contributes to cell-size homeostasis. The critical cell size is modulated by nutrients, such that cells growing in poor nutrients are smaller than cells growing in rich nutrients. Nutrient modulation of cell size does not work through known critical regulators of G1 cyclin transcription and is therefore thought to work through a distinct pathway. Here, we report that Rts1, a highly conserved regulatory subunit of protein phosphatase 2A (PP2A), is required for normal control of G1 cyclin transcription. Loss of Rts1 caused delayed initiation of bud growth and delayed and reduced accumulation of G1 cyclins. Expression of the G1 cyclin CLN2 from an inducible promoter rescued the delayed bud growth in rts1Δ cells, indicating that Rts1 acts at the level of transcription. Moreover, loss of Rts1 caused altered regulation of Swi6, a key component of the SBF transcription factor that controls G1 cyclin transcription. Epistasis analysis revealed that Rts1 does not work solely through several known critical upstream regulators of G1 cyclin transcription. Cells lacking Rts1 failed to undergo nutrient modulation of cell size. Together, these observations demonstrate that Rts1 is a key player in pathways that link nutrient availability, cell size, and G1 cyclin transcription. Since Rts1 is highly conserved, it may function in similar pathways in vertebrates. PMID:19911052

Geraniol and beta-ionone inhibit proliferation, cell cycle progression, and cyclin-dependent kinase 2 activity in MCF-7 breast cancer cells independent of effects on HMG-CoA reductase activity.

PubMed

Duncan, Robin E; Lau, Dominic; El-Sohemy, Ahmed; Archer, Michael C

2004-11-01

3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase catalyzes the formation of mevalonate, a precursor of cholesterol that is also required for cell proliferation. Mevalonate depletion results in a G1 phase cell cycle arrest that is mediated in part by impaired activity of cyclin-dependent kinase (CDK) 2, and decreased expression of positive regulators of G1 to S phase progression. Inhibition of mevalonate synthesis may, therefore, be a useful strategy to impair the growth of malignant cells. Plant isoprenoids, including beta-ionone and geraniol, have previously been shown to inhibit rodent mammary tumor development, and rodent and avian hepatic HMG-CoA reductase activity. We hypothesized that the putative anti-proliferative and cell cycle inhibitory effects of beta-ionone and geraniol on MCF-7 human breast cancer cells in culture are mediated by mevalonate depletion resulting from inhibition of HMG-CoA reductase activity. Flow cytometric analysis showed a G1 arrest in isoprenoid-treated MCF-7 cells, and also a G2/M arrest at higher concentrations of isoprenoids. These compounds minimally affected the growth of MCF-10F normal breast epithelial cells. Both beta-ionone and geraniol inhibited CDK 2 activity and dose-dependently decreased the expression of cyclins D1, E, and A, and CDK 2 and 4, without changing the expression of p21cip1 or p27kip1. Although both beta-ionone and geraniol also inhibited MCF-7 proliferation, only geraniol inhibited HMG-CoA reductase activity. While these effects were significantly correlated (r2=0.89, P <0.01), they were not causally related, since exogenous mevalonate did not restore growth in geraniol-inhibited cells. These findings indicate that mechanisms other than impaired mevalonate synthesis mediate the anti-proliferative and cell cycle regulatory effects of beta-ionone and geraniol in human breast cancer cells.

Involvement of cyclin D and p27 in cell proliferation mediated by ROCK inhibitors Y-27632 and Y-39983 during corneal endothelium wound healing.

PubMed

Okumura, Naoki; Nakano, Shinichiro; Kay, EunDuck P; Numata, Ryohei; Ota, Aya; Sowa, Yoshihiro; Sakai, Toshiyuki; Ueno, Morio; Kinoshita, Shigeru; Koizumi, Noriko

2014-01-15

To investigate the molecular mechanism of Rho-associated kinase (ROCK) inhibitors Y-27632 and Y-39983 on corneal endothelial cell (CEC) proliferation and their wound-healing effect. The expression of G1 proteins of the cell cycle and expression of phosphorylated Akt in monkey CECs (MCECs) treated with Y-27632 were determined by Western blotting. The effect of Y-39983 on the proliferation of MCECs and human CECs (HCECs) was evaluated by both Ki67 staining and incorporation of BrdU. As an in vivo study, Y-39983 was topically instilled in a corneal-endothelial partially injured rabbit model, and CEC proliferation was then evaluated. Investigation of the molecular mechanism of Y-27632 on CEC proliferation revealed that Y-27632 facilitated degradation of p27Kip1 (p27), and promoted the expression of cyclin D. When CECs were stimulated with Y-27632, a 1.7-fold increase in the activation of Akt was seen in comparison to the control after 1 hour. The presence of LY294002, the PI 3-kinase inhibitor, sustained the level of p27. When the efficacy of Y-39983 on cell proliferation was measured in a rabbit model, Y-39983 eye-drop instillation demonstrated rapid wound healing in a concentration range of 0.095 to 0.95 mM, whereas Y-27632 demonstrated rapid wound healing in a concentration range of 3 to 10 mM. These findings show that ROCK inhibitors employ both cyclin D and p27 via PI 3-kinase signaling to promote CEC proliferation, and that Y-39983 may be a more potent agent than Y-27632 for facilitating corneal endothelium wound healing.

Maternal gestational betaine supplementation-mediated suppression of hepatic cyclin D2 and presenilin1 gene in newborn piglets is associated with epigenetic regulation of the STAT3-dependent pathway.

PubMed

Cai, Demin; Yuan, Mengjie; Jia, Yimin; Liu, Haoyu; Hu, Yun; Zhao, Ruqian

2015-12-01

Betaine, which donates methyl groups through methionine metabolism for DNA and protein methylation, is critical for epigenetic gene regulation, especially during fetal development. Here we fed gestational sows with control or betaine supplemented diets (3 g/kg) throughout the pregnancy to explore the effects of maternal betaine on hepatic cell proliferation in neonatal piglets. Neonatal piglets born to betaine-supplemented sows demonstrated a reduction of cell number and DNA content in the liver, which was associated with significantly down-regulated hepatic expression of cell cycle regulatory genes, cyclin D2 (CCND2) and presenilin1 (PSEN1). Moreover, STAT3 binding to the promoter of CCND2 and PSEN1 was also lower in betaine-exposed piglets, accompanied by strong reduction of STAT3 mRNA and protein expression, along with its phosphorylation at Tyr705 and Ser727 residues. Also, prenatal betaine exposure significantly attenuated upstream kinases of STAT3 signaling pathway (phospho-ERK1/2, phospho-SRC and phospho-JAK2) in the livers of neonates. Furthermore, the repressed STAT3 expression in the liver of betaine-exposed piglets was associated with DNA hypermethylation and more enriched repression histone mark H3K27me3 on its promoter, together with significantly up-regulated expression of H3K27me3 and enhancer of zeste homolog 2 (EZH2) proteins, as well as miR-124a, which targets STAT3. Taken together, our results suggest that maternal dietary betaine supplementation during gestation inhibits hepatic cell proliferation in neonatal piglets, at least partly, through epigenetic regulation of hepatic CCND2 and PSEN1 genes via a STAT3-dependent pathway. These neonatal changes in cell cycle and proliferation regulation may lead to lower liver weight and hepatic DNA content at weaning. Copyright © 2015 Elsevier Inc. All rights reserved.

Rb and FZR1/Cdh1 determine CDK4/6-cyclin D requirement in C. elegans and human cancer cells.

PubMed

The, Inge; Ruijtenberg, Suzan; Bouchet, Benjamin P; Cristobal, Alba; Prinsen, Martine B W; van Mourik, Tim; Koreth, John; Xu, Huihong; Heck, Albert J R; Akhmanova, Anna; Cuppen, Edwin; Boxem, Mike; Muñoz, Javier; van den Heuvel, Sander

2015-01-06

Cyclin-dependent kinases 4 and 6 (CDK4/6) in complex with D-type cyclins promote cell cycle entry. Most human cancers contain overactive CDK4/6-cyclin D, and CDK4/6-specific inhibitors are promising anti-cancer therapeutics. Here, we investigate the critical functions of CDK4/6-cyclin D kinases, starting from an unbiased screen in the nematode Caenorhabditis elegans. We found that simultaneous mutation of lin-35, a retinoblastoma (Rb)-related gene, and fzr-1, an orthologue to the APC/C co-activator Cdh1, completely eliminates the essential requirement of CDK4/6-cyclin D (CDK-4/CYD-1) in C. elegans. CDK-4/CYD-1 phosphorylates specific residues in the LIN-35 Rb spacer domain and FZR-1 amino terminus, resembling inactivating phosphorylations of the human proteins. In human breast cancer cells, simultaneous knockdown of Rb and FZR1 synergistically bypasses cell division arrest induced by the CDK4/6-specific inhibitor PD-0332991. Our data identify FZR1 as a candidate CDK4/6-cyclin D substrate and point to an APC/C(FZR1) activity as an important determinant in response to CDK4/6-inhibitors.

Rb and FZR1/Cdh1 determine CDK4/6-cyclin D requirement in C. elegans and human cancer cells

PubMed Central

The, Inge; Ruijtenberg, Suzan; Bouchet, Benjamin P.; Cristobal, Alba; Prinsen, Martine B. W.; van Mourik, Tim; Koreth, John; Xu, Huihong; Heck, Albert J. R.; Akhmanova, Anna; Cuppen, Edwin; Boxem, Mike; Muñoz, Javier; van den Heuvel, Sander

2015-01-01

Cyclin-dependent kinases 4 and 6 (CDK4/6) in complex with D-type cyclins promote cell cycle entry. Most human cancers contain overactive CDK4/6-cyclin D, and CDK4/6-specific inhibitors are promising anti-cancer therapeutics. Here, we investigate the critical functions of CDK4/6-cyclin D kinases, starting from an unbiased screen in the nematode Caenorhabditis elegans. We found that simultaneous mutation of lin-35, a retinoblastoma (Rb)-related gene, and fzr-1, an orthologue to the APC/C co-activator Cdh1, completely eliminates the essential requirement of CDK4/6-cyclin D (CDK-4/CYD-1) in C. elegans. CDK-4/CYD-1 phosphorylates specific residues in the LIN-35 Rb spacer domain and FZR-1 amino terminus, resembling inactivating phosphorylations of the human proteins. In human breast cancer cells, simultaneous knockdown of Rb and FZR1 synergistically bypasses cell division arrest induced by the CDK4/6-specific inhibitor PD-0332991. Our data identify FZR1 as a candidate CDK4/6-cyclin D substrate and point to an APC/CFZR1 activity as an important determinant in response to CDK4/6-inhibitors. PMID:25562820

Disorder of G2-M Checkpoint Control in Aniline-Induced Cell Proliferation in Rat Spleen.

PubMed

Wang, Jianling; Wang, Gangduo; Khan, M Firoze

2015-01-01

Aniline, a toxic aromatic amine, is known to cause hemopoietic toxicity both in humans and animals. Aniline exposure also leads to toxic response in spleen which is characterized by splenomegaly, hyperplasia, fibrosis and the eventual formation of tumors on chronic in vivo exposure. Previously, we have shown that aniline exposure leads to iron overload, oxidative DNA damage, and increased cell proliferation, which could eventually contribute to a tumorigenic response in the spleen. Despite our demonstration that cell proliferation was associated with deregulation of G1 phase cyclins and increased expression of G1 phase cyclin-dependent kinases (CDKs), molecular mechanisms, especially the regulation of G2 phase and contribution of epigenetic mechanisms in aniline-induced splenic cellular proliferation remain largely unclear. This study therefore, mainly focused on the regulation of G2 phase in an animal model preceding a tumorigenic response. Male Sprague-Dawley rats were given aniline (0.5 mmol/kg/day) in drinking water or drinking water only (controls) for 30 days, and expression of G2 phase cyclins, CDK1, CDK inhibitors and miRNAs were measured in the spleen. Aniline treatment resulted in significant increases in cell cycle regulatory proteins, including cyclins A, B and CDK1, particularly phosphor-CDK1, and decreases in CDK inhibitors p21 and p27, which could promote the splenocytes to go through G2/M transition. Our data also showed upregulation of tumor markers Trx-1 and Ref-1 in rats treated with aniline. More importantly, we observed lower expression of miRNAs including Let-7a, miR-15b, miR24, miR-100 and miR-125, and greater expression of CDK inhibitor regulatory miRNAs such as miR-181a, miR-221 and miR-222 in the spleens of aniline-treated animals. Our findings suggest that significant increases in the expression of cyclins, CDK1 and aberrant regulation of miRNAs could lead to an accelerated G2/M transition of the splenocytes, and potentially to a tumorigenic response on chronic aniline exposure.

Disorder of G2-M Checkpoint Control in Aniline-Induced Cell Proliferation in Rat Spleen

PubMed Central

Wang, Jianling; Wang, Gangduo; Khan, M. Firoze

2015-01-01

Aniline, a toxic aromatic amine, is known to cause hemopoietic toxicity both in humans and animals. Aniline exposure also leads to toxic response in spleen which is characterized by splenomegaly, hyperplasia, fibrosis and the eventual formation of tumors on chronic in vivo exposure. Previously, we have shown that aniline exposure leads to iron overload, oxidative DNA damage, and increased cell proliferation, which could eventually contribute to a tumorigenic response in the spleen. Despite our demonstration that cell proliferation was associated with deregulation of G1 phase cyclins and increased expression of G1 phase cyclin-dependent kinases (CDKs), molecular mechanisms, especially the regulation of G2 phase and contribution of epigenetic mechanisms in aniline-induced splenic cellular proliferation remain largely unclear. This study therefore, mainly focused on the regulation of G2 phase in an animal model preceding a tumorigenic response. Male Sprague-Dawley rats were given aniline (0.5 mmol/kg/day) in drinking water or drinking water only (controls) for 30 days, and expression of G2 phase cyclins, CDK1, CDK inhibitors and miRNAs were measured in the spleen. Aniline treatment resulted in significant increases in cell cycle regulatory proteins, including cyclins A, B and CDK1, particularly phosphor-CDK1, and decreases in CDK inhibitors p21 and p27, which could promote the splenocytes to go through G2/M transition. Our data also showed upregulation of tumor markers Trx-1 and Ref-1 in rats treated with aniline. More importantly, we observed lower expression of miRNAs including Let-7a, miR-15b, miR24, miR-100 and miR-125, and greater expression of CDK inhibitor regulatory miRNAs such as miR-181a, miR-221 and miR-222 in the spleens of aniline-treated animals. Our findings suggest that significant increases in the expression of cyclins, CDK1 and aberrant regulation of miRNAs could lead to an accelerated G2/M transition of the splenocytes, and potentially to a tumorigenic response on chronic aniline exposure. PMID:26192324

Keratin14 mRNA expression in human pneumocytes during quiescence, repair and disease

PubMed Central

Confalonieri, Marco; Buratti, Emanuele; Grassi, Gabriele; Bussani, Rossana; Chilosi, Marco; Farra, Rossella; Abrami, Michela; Stuani, Cristiana; Salton, Francesco; Ficial, Miriam; Confalonieri, Paola; Zandonà, Lorenzo; Romano, Maurizio

2017-01-01

The lung alveoli slowly self-renew pneumocytes, but their facultative regeneration capacity is rapidly efficient after an injury, so fibrosis infrequently occurs. We recently observed Keratin 14 (KRT14) expression during diffuse alveolar damage (DAD), but not in controls. We wonder if KRT14 may be a marker of pneumocyte transition from quiescence to regeneration. Quantitative PCR and Western blot analyses highlighted the presence of KRT14 (mRNA and protein) only in human lung samples with DAD or interstitial lung disease (ILD). In the exponentially growing cell lines A549 and H441, the mRNA and protein levels of KRT14 peaked at day one after cell seeding and decreased at day two, opposite to what observed for the proliferation marker E2F1. The inverse relation of KRT14 versus E2F1 expression holds true also for other proliferative markers, such as cyclin E1 and cyclin D1. Of interest, we also found that E2F1 silencing caused cell cycle arrest and increased KRT14 expression, whilst E2F1 stimulation induced cell cycle progression and decreased KRT14. KRT14 also increased in proliferative pneumocytes (HPAEpiC) just before transdifferentiation. Overall, our results suggest that KRT14 is a viable biomarker of pneumocyte activation, and repair/regeneration. The involvement of KRT14 in regenerative process may suggest a novel pharmaceutical target to accelerate lung repair. PMID:28199407

Keratin14 mRNA expression in human pneumocytes during quiescence, repair and disease.

PubMed

Confalonieri, Marco; Buratti, Emanuele; Grassi, Gabriele; Bussani, Rossana; Chilosi, Marco; Farra, Rossella; Abrami, Michela; Stuani, Cristiana; Salton, Francesco; Ficial, Miriam; Confalonieri, Paola; Zandonà, Lorenzo; Romano, Maurizio

2017-01-01

The lung alveoli slowly self-renew pneumocytes, but their facultative regeneration capacity is rapidly efficient after an injury, so fibrosis infrequently occurs. We recently observed Keratin 14 (KRT14) expression during diffuse alveolar damage (DAD), but not in controls. We wonder if KRT14 may be a marker of pneumocyte transition from quiescence to regeneration. Quantitative PCR and Western blot analyses highlighted the presence of KRT14 (mRNA and protein) only in human lung samples with DAD or interstitial lung disease (ILD). In the exponentially growing cell lines A549 and H441, the mRNA and protein levels of KRT14 peaked at day one after cell seeding and decreased at day two, opposite to what observed for the proliferation marker E2F1. The inverse relation of KRT14 versus E2F1 expression holds true also for other proliferative markers, such as cyclin E1 and cyclin D1. Of interest, we also found that E2F1 silencing caused cell cycle arrest and increased KRT14 expression, whilst E2F1 stimulation induced cell cycle progression and decreased KRT14. KRT14 also increased in proliferative pneumocytes (HPAEpiC) just before transdifferentiation. Overall, our results suggest that KRT14 is a viable biomarker of pneumocyte activation, and repair/regeneration. The involvement of KRT14 in regenerative process may suggest a novel pharmaceutical target to accelerate lung repair.

Sepsis reveals compartment-specific responses in intestinal proliferation and apoptosis in transgenic mice whose enterocytes re-enter the cell cycle.

PubMed

Lyons, John D; Klingensmith, Nathan J; Otani, Shunsuke; Mittal, Rohit; Liang, Zhe; Ford, Mandy L; Coopersmith, Craig M

2017-12-01

Cell production and death are tightly regulated in the rapidly renewing gut epithelium, with proliferation confined to crypts and apoptosis occurring in villi and crypts. This study sought to determine how stress alters these compartmentalized processes. Wild-type mice made septic via cecal ligation and puncture had decreased crypt proliferation and increased crypt and villus apoptosis. Fabpi -TAg mice expressing large T-antigen solely in villi had ectopic enterocyte proliferation with increased villus apoptosis in unmanipulated animals. Septic fabpi -TAg mice had an unexpected increase in villus proliferation compared with unmanipulated littermates, whereas crypt proliferation was decreased. Cell cycle regulators cyclin D1 and cyclin D2 were decreased in jejunal tissue in septic transgenic mice. In contrast, villus and crypt apoptosis were increased in septic fabpi -TAg mice. To examine the relationship between apoptosis and proliferation in a compartment-specific manner, fabpi -TAg mice were crossed with fabpl -Bcl-2 mice, resulting in expression of both genes in the villus but Bcl-2 alone in the crypt. Septic bi-transgenic animals had decreased crypt apoptosis but had a paradoxical increase in villus apoptosis compared with septic fabpi -TAg mice, associated with decreased proliferation in both compartments. Thus, sepsis unmasks compartment-specific proliferative and apoptotic regulation that is not present under homeostatic conditions.-Lyons, J. D., Klingensmith, N. J., Otani, S., Mittal, R., Liang, Z., Ford, M. L., Coopersmith, C. M. Sepsis reveals compartment-specific responses in intestinal proliferation and apoptosis in transgenic mice whose enterocytes re-enter the cell cycle. © FASEB.

Identification of a mouse B-type cyclin which exhibits developmentally regulated expression in the germ line

NASA Technical Reports Server (NTRS)

Chapman, D. L.; Wolgemuth, D. J.

1992-01-01

To begin to examine the function of cyclins in mammalian germ cells, we have screened an adult mouse testis cDNA library for the presence of B-type cyclins. We have isolated cDNAs that encode a murine B-type cyclin, which has been designated cycB1. cycB1 was shown to be expressed in several adult tissues and in the midgestation mouse embryo. In the adult tissues, the highest levels of cycB1 transcripts were seen in the testis and ovary, which contain germ cells at various stages of differentiation. The major transcripts corresponding to cycB1 are 1.7 and 2.5 kb, with the 1.7 kb species being the predominant testicular transcript and the 2.5 kb species more abundant in the ovary. Examination of cDNAs corresponding to the 2.5 kb and 1.7 kb mRNAs revealed that these transcripts encode identical proteins, differing only in the polyadenylation signal used and therefore in the length of their 3' untranslated regions. Northern blot and in situ hybridization analyses revealed that the predominant sites of cycB1 expression in the testis and ovary were in the germinal compartment, particularly in early round spermatids in the testis and growing oocytes in the ovary. Thus cycB1 is expressed in both meiotic and postmeiotic cells. This pattern of cycB1 expression further suggests that cycB1 may have different functions in the two cell types, only one of which correlates with progression of the cell cycle.

Molecular Modeling Studies of 4,5-Dihydro-1H-pyrazolo[4,3-h] quinazoline Derivatives as Potent CDK2/Cyclin A Inhibitors Using 3D-QSAR and Docking

PubMed Central

Ai, Yong; Wang, Shao-Teng; Sun, Ping-Hua; Song, Fa-Jun

2010-01-01

CDK2/cyclin A has appeared as an attractive drug targets over the years with diverse therapeutic potentials. A computational strategy based on comparative molecular fields analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) followed by molecular docking studies were performed on a series of 4,5-dihydro-1H-pyrazolo[4,3-h]quinazoline derivatives as potent CDK2/cyclin A inhibitors. The CoMFA and CoMSIA models, using 38 molecules in the training set, gave r2cv values of 0.747 and 0.518 and r2 values of 0.970 and 0.934, respectively. 3D contour maps generated by the CoMFA and CoMSIA models were used to identify the key structural requirements responsible for the biological activity. Molecular docking was applied to explore the binding mode between the ligands and the receptor. The information obtained from molecular modeling studies may be helpful to design novel inhibitors of CDK2/cyclin A with desired activity. PMID:21152296

Molecular modeling studies of 4,5-dihydro-1H-pyrazolo[4,3-h] quinazoline derivatives as potent CDK2/Cyclin a inhibitors using 3D-QSAR and docking.

PubMed

Ai, Yong; Wang, Shao-Teng; Sun, Ping-Hua; Song, Fa-Jun

2010-09-28

CDK2/cyclin A has appeared as an attractive drug targets over the years with diverse therapeutic potentials. A computational strategy based on comparative molecular fields analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) followed by molecular docking studies were performed on a series of 4,5-dihydro-1H-pyrazolo[4,3-h]quinazoline derivatives as potent CDK2/cyclin A inhibitors. The CoMFA and CoMSIA models, using 38 molecules in the training set, gave r(2) (cv) values of 0.747 and 0.518 and r(2) values of 0.970 and 0.934, respectively. 3D contour maps generated by the CoMFA and CoMSIA models were used to identify the key structural requirements responsible for the biological activity. Molecular docking was applied to explore the binding mode between the ligands and the receptor. The information obtained from molecular modeling studies may be helpful to design novel inhibitors of CDK2/cyclin A with desired activity.

Role of magnolol in the proliferation of vascular smooth muscle cells.

PubMed

Wu, L; Zou, H; Xia, W; Dong, Q; Wang, L

2015-05-01

Proliferation of vascular smooth muscle cells (VSMCs) contributes to the development of vascular remodeling. Recently, magnolol has been reported to have a potential role in regulating tumor necrosis factor α-induced proliferation of VSMCs. However, the role of magnolol in platelet-derived growth factor (PDGF)-induced proliferation of VSMCs remains unknown. Our purpose was to elucidate the effect of magnolol on the proliferation of VSMCs induced by PDGF-BB and to investigate the underlying molecular mechanisms. Our data demonstrated that magnolol inhibited rat VSMC proliferation and DNA synthesis stimulated by 20 ng/ml PDGF-BB without causing cell cytotoxicity. Flow cytometric analysis showed that magnolol inhibited S-phase entry of VSMCs. We also demonstrated that magnolol caused this effect by inhibiting the mRNA and protein expression of cyclin D1, cyclin E, and cyclin-dependent kinases 2 and 4 in PDGF-BB-stimulated VSMCs. Further analysis showed that the inhibitory effect of magnolol on the proliferation of VSMCs was associated with the inhibition of the PDGF-BB-stimulated production of intracellular reactive oxygen species (ROS) and Ras, MEK, and ERK1/2 activation. These results demonstrate that magnolol can block the proliferation of VSMCs through inhibition of intracellular ROS production and Ras-MEK-ERK1/2 pathways. Magnolol, therefore, has a potential application in preventing atherosclerosis and restenosis.

Aluminum trichloride impairs bone and downregulates Wnt/β-catenin signaling pathway in young growing rats.

PubMed

Sun, Xudong; Cao, Zheng; Zhang, Qiuyue; Liu, Shimin; Xu, Feibo; Che, Jianfang; Zhu, Yanzhu; Li, Yanfei; Pan, Chuanyi; Liang, Wannan

2015-12-01

Aluminum (Al) can accumulate in bone and cause bone diseases. Few studies have investigated molecular mechanism of Al-induced bone diseases. Thus, in this study, rats were orally exposed to 0 (control group) and 0.4 g/L aluminum trichloride (AlCl3) (treatment group) for 30, 60, 90 or 120 days, respectively. The Al content of femora and serum, bone histological structure, bone mineral density (BMD) of the distal and proximal femoral metaphysis and Wnt/β-catenin signaling pathway (the mRNA expressions of Wnt3a, Fzd2, LRP-5, β-catenin, Tcf4, cyclin D1 and c-Myc, the protein levels of Wnt3a and β-catenin, the activities of Fzd2 and LRP-5) in rat femora were determined on day 30, 60, 90 or 120, respectively. The results showed that the Al contents of femora and serum were increased, the BMD of the distal and proximal femoral metaphysis were decreased, the femora histological structure were disrupted, the mRNA expressions of Wnt3a, Fzd2, LRP-5, β-catenin, Tcf4, cyclin D1 and c-Myc, the protein levels of Wnt3a and β-catenin, the activities of Fzd2 and LRP-5 were all decreased in the treatment group compared with the control group with time prolonged. These results indicated that AlCl3 impaired femora by inhibiting the Wnt/β-catenin signaling pathway in young growing rats. Copyright © 2015 Elsevier Ltd. All rights reserved.

Black tea and D. candidum extracts play estrogenic activity via estrogen receptor α-dependent signaling pathway

PubMed Central

Wang, Yongsen; Sun, Jing; Zhang, Kun; Hu, Xin; Sun, Yuchu; Sheng, Jun; Fu, Xueqi

2018-01-01

In recent years, phytoestrogens have been shown as useful selective estrogen receptor modulators. The estrogen-like effects of black tea (BT) and D. candidum (DC), as well as the combination of the two herbs, have remained largely elusive. This study aims to investigate the phytoestrogenic effect of BT and DC extract, and the possible mechanism. The effects on T47D (ER+ cell line) proliferation were evaluated by using MTT assay. The S phase proportion of ER+ cells was determined by using flow cytometry. The estrogen antagonist ICI 182,780 was applied to block the ER function. The activation of ER-mediated PI3K/AKT and ERK signal pathways were observed by using western blot. Expression of ERα and PGR, as well as PS2 and Cyclin D1 were detected by using western blot and real-time quantitative PCR. Firstly, our results found that BT and DC extracts promoted cell proliferation in ER-positive cells, and this effect was ER-dependent. Besides, BT and DC extracts increased the S-phase cell number. Next, PI3K, AKT and ERK pathways below ER were activated by phytoestrogen treatment, and this activation was blocked by the ER antagonist. Moreover, prolonged BT and DC treatments increased the expression of ESR1 and PGR. Consistently, the mRNA levels of not only ESR1 and PGR but also estrogen-dependent effectors ps2 and cyclin D1, were increased by phytoestrogens and blocked by ICI 182,780. Taken Together, BT and DC extracts have phytoestrogenic effects, and this may provide new ideas and experimental basis for the development and application of phytoestrogens. PMID:29422998

Impaired liver regeneration is associated with reduced cyclin B1 in natural killer T cell-deficient mice.

PubMed

Ben Ya'acov, Ami; Meir, Hadar; Zolotaryova, Lydia; Ilan, Yaron; Shteyer, Eyal

2017-03-23

It has been shown that the proportion of natural killer T cells is markedly elevated during liver regeneration and their activation under different conditions can modulate this process. As natural killer T cells and liver injury are central in liver regeneration, elucidating their role is important. The aim of the current study is to explore the role of natural killer T cells in impaired liver regeneration. Concanvalin A was injected 4 days before partial hepatectomy to natural killer T cells- deficient mice or to anti CD1d1-treated mice. Ki-67 and proliferating cell nuclear antigen were used to measure hepatocytes proliferation. Expression of hepatic cyclin B1 and proliferating cell nuclear antigen were evaluated by Western Blot and liver injury was assessed by ALT and histology. Natural killer T cells- deficient or mice injected with anti CD1d antibodies exhibited reduced liver regeneration. These mice were considerably resistant to ConA-induced liver injury. In the absence of NKT cells hepatic proliferating cell nuclear antigen and cyclin B1 decreased in mice injected with Concanvalin A before partial hepatectomy. This was accompanied with reduced serum interleukin-6 levels. Natural killer T cells play an important role in liver regeneration, which is associated with cyclin B1 and interleukin-6.

NeoPalAna: Neoadjuvant palbociclib, a cyclin-dependent kinase 4/6 inhibitor, and anastrozole for clinical stage 2 or 3 estrogen receptor positive breast cancer

PubMed Central

Ma, Cynthia X.; Gao, Feng; Luo, Jingqin; Northfelt, Donald W.; Goetz, Matthew; Forero, Andres; Hoog, Jeremy; Naughton, Michael; Ademuyiwa, Foluso; Suresh, Rama; Anderson, Karen S.; Margenthaler, Julie; Aft, Rebecca; Hobday, Timothy; Moynihan, Timothy; Gillanders, William; Cyr, Amy; Eberlein, Timothy J.; Hieken, Tina; Krontiras, Helen; Guo, Zhanfang; Lee, Michelle V.; Spies, Nicholas C.; Skidmore, Zachary L.; Griffith, Obi L.; Griffith, Malachi; Thomas, Shana; Bumb, Caroline; Vij, Kiran; Bartlett, Cynthia Huang; Koehler, Maria; Al-Kateb, Hussam; Sanati, Souzan; Ellis, Matthew J.

2017-01-01

Purpose Cyclin-dependent kinase (CDK) 4/6 drives cell proliferation in estrogen receptor positive (ER+) breast cancer. This single-arm phase II neoadjuvant trial (NeoPalAna) assessed the anti-proliferative activity of the CDK4/6 inhibitor palbociclib in primary breast cancer as a prelude to adjuvant studies. Experimental Design Eligible patients with clinical stage II/III ER+/HER2- breast cancer received anastrozole 1mg daily for 4 weeks (cycle 0) (with goserelin if premenopausal), followed by adding palbociclib (125mg daily on days 1-21) on cycle 1 day 1 (C1D1) for four 28-day cycles unless C1D15 Ki67>10%, in which case patients went off study due to inadequately response. Anastrozole was continued until surgery, which occurred 3-5 weeks post palbociclib exposure. Later patients received additional 10-12 days of palbociclib (Cycle 5) immediately before surgery. Serial biopsies at baseline, C1D1, C1D15, and surgery were analyzed for Ki67, gene expression and mutation profiles. The primary endpoint was Complete Cell Cycle Arrest (CCCA: central Ki67<2.7%). Results Fifty patients enrolled. The CCCA rate was significantly higher after adding palbociclib to anastrozole (C1D15 87% vs C1D1 26%, p<0.001). Palbociclib enhanced cell cycle control over anastrozole monotherapy regardless of luminal subtype (A vs B) and PIK3CA status with activity observed across a broad range of clinicopathological and mutation profiles. Ki67 recovery at surgery following palbociclib washout was suppressed by cycle 5 palbociclib. Resistance was associated with non-luminal subtypes and persistent E2F-target gene expression. Conclusions Palbociclib is an active anti-proliferative agent for early-stage breast cancer resistant to anastrozole, however, prolonged administration may be necessary to maintain its effect. PMID:28270497

1α,25(OH)2-dihydroxyvitamin D3/VDR protects the skin from UVB-induced tumor formation by interacting with the β-catenin pathway.

PubMed

Jiang, Yan J; Teichert, Arnaud E; Fong, Frankie; Oda, Yuko; Bikle, Daniel D

2013-07-01

Ultra violet (UV) irradiation, in particular UVB, is the single most important carcinogen for skin tumor formation. UVB induces genetic mutations and immune suppression, which lead to abnormal cell proliferation and eventually tumor formation. Previously studies from our group and others demonstrated that both global and epidermal specific VDR knock out mice are predisposed to either chemical (DMBA)- or long-term UVB-induced skin tumor formation, paralleled by an increase in β-catenin signaling. Using primary cultured human keratinocytes, we further demonstrated that 1,25(OH)2-dihydroxyvitamin D3 (1,25(OH)2D3) suppresses cyclin D1 and Gli1 which are regulated by β-catenin/TCF signaling and have a critical role in epidermal carcinogenesis. Blockage of VDR by siRNA resulted in hyperproliferation of keratinocytes, and increased expression of cyclin D1 and Gli1. In addition, we also showed that 1,25(OH)2D3/VDR directly regulates transcriptional activity of β-catenin/TCF signaling using the -catenin reporter TopGlow. Using K14 driven tamoxifen-induced cre recombinase to delete both VDR and β-catenin in keratinocytes of mice following the first hair follicle cycle, we found that ablation of epidermal specific β-catenin cannot rescue VDR null mice from UVB-induced skin tumor formation. Further study using VDR or β-catenin single null mice is necessary to compare with the data from double null mice. This article is part of a Special Issue entitled 'Vitamin D Workshop'. Copyright © 2012 Elsevier Ltd. All rights reserved.

Spliceosomal protein E regulates neoplastic cell growth by modulating expression of cyclin E/CDK2 and G2/M checkpoint proteins.

PubMed

Li, Z; Pützer, B M

2008-12-01

Small nuclear ribonucleoproteins are essential splicing factors. We previously identified the spliceosomal protein E (SmE) as a downstream effector of E2F1 in p53-deficient human carcinoma cells. Here, we investigated the biological relevance of SmE in determining the fate of cancer and non-tumourigenic cells. Adenovirus-mediated expression of SmE selectively reduces growth of cancerous cells due to decreased cell proliferation but not apoptosis. A similar growth inhibitory effect for SmD1 suggests that this is a general function of Sm-family members. Deletion of Sm-motifs reveals the importance of the Sm-1 domain for growth suppression. Consistently, SmE overexpression leads to inhibition of DNA synthesis and G2 arrest as shown by BrdU-incorporation and MPM2-staining. Real-time RT-PCR and immunoblotting showed that growth arrest by SmE directly correlates with the reduction of cyclin E, CDK2, CDC25C and CDC2 expression, and up-regulation of p27Kip. Importantly, SmE activity was not associated with enhanced expression of other spliceosome components such as U1 SnRNP70, suggesting that the growth inhibitory effect of SmE is distinct from its pre-mRNA splicing function. Furthermore, specific inactivation of SmE by shRNA significantly increased the percentage of cells in S phase, whereas the amount of G2/M arrested cells was reduced. Our data provide evidence that Sm proteins function as suppressors of tumour cell growth and may have major implications as cancer therapeutics.

Basic Fibroblast Growth Factor Regulates Gene and Protein Expression Related to Proliferation, Differentiation, and Matrix Production of Human Dental Pulp Cells.

PubMed

Chang, Ya-Ching; Chang, Mei-Chi; Chen, Yi-Jane; Liou, Ji-Uei; Chang, Hsiao-Hua; Huang, Wei-Ling; Liao, Wan-Chuen; Chan, Chiu-Po; Jeng, Po-Yuan; Jeng, Jiiang-Huei

2017-06-01

Basic fibroblast growth factor (bFGF) plays differential effects on the proliferation, differentiation, and extracellular matrix turnover in various tissues. However, limited information is known about the effect of bFGF on dental pulp cells. The purposes of this study were to investigate whether bFGF influences the cell differentiation and extracellular matrix turnover of human dental pulp cells (HDPCs) and the related gene and protein expression as well as the role of the mitogen-activated protein kinase (MEK)/extracellular-signal regulated kinase (ERK) signaling pathway. The expression of fibroblast growth factor receptors (FGFRs) in HDPCs was also studied. The expression of FGFR1 and FGFR2 in HDPCs was investigated by reverse-transcription polymerase chain reaction. HDPCs were treated with different concentrations of bFGF. Cell proliferation was evaluated using the 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Cell differentiation was evaluated using alkaline phosphatase (ALP) staining. Changes in messenger expression of cyclin B1 and tissue inhibitor of metalloproteinase (TIMP) 1 were determined by reverse-transcription polymerase chain reaction. Changes in protein expression of cdc2, TIMP-1, TIMP-2, and collagen I were determined by Western blotting. U0126 was used to clarify the role of MEK/ERK signaling. HDPCs expressed both FGFR1 and FGFR2. Cell viability was stimulated by 50-250 ng/mL bFGF. The expression and enzyme activities of ALP were inhibited by 10-500 ng/mL bFGF. At similar concentrations, bFGF stimulates cdc2, cyclin B1, and TIMP-1 messenger RNA and protein expression. bFGF showed little effect on TIMP-2 and partly inhibited collagen I expression of pulp cells. U0126 (a MEK/ERK inhibitor) attenuated the bFGF-induced increase of cyclin B1, cdc2, and TIMP-1. bFGF may be involved in pulpal repair and regeneration by activation of FGFRs to regulate cell growth; stimulate cdc2, cyclin B1, and TIMP-1 expression; and inhibit ALP. These events are partly associated with MEK/ERK signaling. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

[6]-Gingerol enhances the radiosensitivity of gastric cancer via G2/M phase arrest and apoptosis induction.

PubMed

Luo, Youjun; Chen, Xue; Luo, Lumeng; Zhang, Qi; Gao, Caixia; Zhuang, Xibing; Yuan, Sujuan; Qiao, Tiankui

2018-05-01

Ionizing radiation (IR) is the main modality for locoregional control of unresectable gastric cancer (GC). [6]-Gingerol is an active major phenolic compound isolated from ginger (Zingiber officinale Roscoe), and it has been demonstrated to possess antitumor activity in previous studies. In the present study, we aimed to evaluate the potential activity of [6]-gingerol as a radiosensitizer and to further explore the underlying mechanism. A CCK-8 assay revealed that [6]-gingerol inhibited the cell viability of HGC-27 cells in a dose-dependent manner (P<0.05). Colony formation assay indicated that pretreatment of [6]-gingerol prior to IR decreased the clonogenic survival of HGC-27 cells. Notably, the combination of [6]-gingerol with IR enhanced IR-induced cell cycle arrest at the G2/M phase compared with IR alone (41.3% in IR alone vs. 53.5% in [6]-gingerol+IR; P=0.006), and increased IR-induced apoptosis compared with IR alone (9.6% in IR alone group vs. 15.1% in [6]-gingerol+IR; P=0.07). DAPI staining detected the apoptotic nuclear morphological changes in the cells treated with [6]-gingerol and/or IR. Furthermore, western blotting and qRT-PCR revealed that [6]-gingerol pretreatment following IR downregulated the protein expression of cyclin B1, cyclin A2, CDC2 and cyclin D1, upregulated the mRNA expression of p27, and induced active caspase-9, active caspase-3 and cytochrome c. In conclusion, the present study demonstrated that [6]-gingerol enhanced radiosensitivity of GC cells, and that the mechanisms involved at least G2/M phase arrest and apoptosis induction.

Cyclin K dependent regulation of Aurora B affects apoptosis and proliferation by induction of mitotic catastrophe in prostate cancer.

PubMed

Schecher, Sabrina; Walter, Britta; Falkenstein, Michael; Macher-Goeppinger, Stephan; Stenzel, Philipp; Krümpelmann, Kristina; Hadaschik, Boris; Perner, Sven; Kristiansen, Glen; Duensing, Stefan; Roth, Wilfried; Tagscherer, Katrin E

2017-10-15

Cyclin K plays a critical role in transcriptional regulation as well as cell development. However, the role of Cyclin K in prostate cancer is unknown. Here, we describe the impact of Cyclin K on prostate cancer cells and examine the clinical relevance of Cyclin K as a biomarker for patients with prostate cancer. We show that Cyclin K depletion in prostate cancer cells induces apoptosis and inhibits proliferation accompanied by an accumulation of cells in the G2/M phase. Moreover, knockdown of Cyclin K causes mitotic catastrophe displayed by multinucleation and spindle multipolarity. Furthermore, we demonstrate a Cyclin K dependent regulation of the mitotic kinase Aurora B and provide evidence for an Aurora B dependent induction of mitotic catastrophe. In addition, we show that Cyclin K expression is associated with poor biochemical recurrence-free survival in patients with prostate cancer treated with an adjuvant therapy. In conclusion, targeting Cyclin K represents a novel, promising anti-cancer strategy to induce cell cycle arrest and apoptotic cell death through induction of mitotic catastrophe in prostate cancer cells. Moreover, our results indicate that Cyclin K is a putative predictive biomarker for clinical outcome and therapy response for patients with prostate cancer. © 2017 UICC.

A peroxisome proliferator-activated receptor ligand MCC-555 imparts anti-proliferative response in pancreatic cancer cells by PPARgamma-independent up-regulation of KLF4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Min, Kyung-Won; Zhang, Xiaobo; College of Animal Science and Technology, Northwest A and F University, Yangling, Shaanxi, 712100

2012-09-01

MCC-555 is a novel PPARα/γ dual ligand of the thiazolidinedione class and was recently developed as an anti-diabetic drug with unique properties. MCC-555 also has anti-proliferative activity through growth inhibition and apoptosis induction in several cancer cell types. Our group has shown that MCC-555 targets several proteins in colorectal tumorigenesis including nonsteroidal anti-inflammatory drug (NSAID)-activated gene (NAG-1) which plays an important role in chemoprevention responsible for chemopreventive compounds. NAG-1 is a member of the TGF-β superfamily and is involved in tumor progression and development; however, NAG-1's roles in pancreatic cancer have not been studied. In this report, we found thatmore » MCC-555 alters not only NAG-1 expression, but also p21 and cyclin D1 expression. NAG-1 and p21 expression was not blocked by PPARγ-specific antagonist GW9662, suggesting that MCC-555-induced NAG-1 and p21 expression is independent of PPARγ activation. However, decreasing cyclin D1 by MCC-555 seems to be affected by PPARγ activation. Further, we found that the GC box located in the NAG-1 promoter play an important role in NAG-1 transactivation by MCC-555. Subsequently, we screened several transcription factors that may bind to the GC box region in the NAG-1 promoter and found that KLF4 potentially binds to this region. Expression of KLF4 precedes NAG-1 and p21 expression in the presence of MCC-555, whereas blocking KLF4 expression using specific KLF4 siRNA showed that both NAG-1 and p21 expression by MCC-555 was blocked. In conclusion, MCC-555's actions on anti-proliferation involve both PPARγ-dependent and -independent pathways, thereby enhancing anti-tumorigenesis in pancreatic cancer cells. -- Highlights: ► PPARα/γ ligand MCC-555 exhibits anti-proliferative activity in pancreatic cancer cells. ► MCC-555 affects KLF4 expression following by NAG-1 and p21 expression in a PPARγ independent manner. ► MCC-555 also affects cyclin D1 down-regulation in a PPARγ dependent manner. ► To our knowledge, this is the first report that MCC-555 affects anti-proliferative activity in pancreatic cancer cells, along with multiple targets.« less

Bioactive fraction of Rhodiola algida against chronic hypoxia-induced pulmonary arterial hypertension and its anti-proliferation mechanism in rats.

PubMed

Nan, Xingmei; Su, Shanshan; Ma, Ke; Ma, Xiaodong; Wang, Ximeng; Zhaxi, Dongzhu; Ge, Rili; Li, Zhanqiang; Lu, Dianxiang

2018-04-24

Rhodiola algida var. tangutica (Maxim.) S.H. Fu is a perennial plant of the Crassulaceae family that grows in the mountainous regions of Asia. The rhizome and roots of this plant have been long used as Tibetan folk medicine for preventing high latitude sickness. The aim of this study was to determine the effect of bioactive fraction from R. algida (ACRT) on chronic hypoxia-induced pulmonary arterial hypertension (HPAH) and to understand the possible mechanism of its pharmacodynamic actions. Male Sprague-Dawley rats were separated into five groups: control group, hypoxia group, and hypoxia+ACRT groups (62.5, 125, and 250mg/kg/day of ACRT). The chronic hypoxic environment was created in a hypobaric chamber by adjusting the inner pressure and oxygen content for 4 weeks. After 4 weeks, major physiological parameters of pulmonary arterial hypertension such as mPAP, right ventricle index (RV/LV+S, RVHI), hematocrit (Hct) levels and the medial vessel thickness (wt%) were measured. Protein and mRNA expression levels of proliferating cell nuclear antigen (PCNA), cyclin D1, p27Kip1 and cyclin-dependent kinase 4 (CDK4)) were detected by western blotting and real time PCR respectively. Chemical profile of ACRT was revealed by ultra performance liquid chromatography coupled with quadrupole time of flight mass spectrometry (UHPLC-Q-TOF-MS/MS). The results showed that a successful HPAH rat model was established in a hypobaric chamber for 4 weeks, as indicated by the significant increase in mPAP, RV/LV+S, RV/BW and wt%. Compared with the normal group, administration of ACRT reduced mPAP, right ventricular hypertrophy, pulmonary small artery wall thickness, and damage in ultrastructure induced by hypoxia in rats. PCNA, cyclin D1, and CDK4 expression was reduced (p<0.05), and p27Kip1 expression increased (p<0.05) in hypoxia+ACRT groups compared to hypoxia. 38 constituents in bioactive fraction were identified by UHPLC-Q-TOF-MS/MS. Our results suggest that ACRT could alleviate chronic hypoxia-induced pulmonary arterial hypertension. And its anti-proliferation mechanism in rats based on decreasing PCNA, cyclin D1, CDK4 expression level and inhibiting p27Kip1 degradation. Copyright © 2018 Elsevier B.V. All rights reserved.

The absence of p27Kip1, an inhibitor of G1 cyclin-dependent kinases, uncouples differentiation and growth arrest during the granulosa->luteal transition.

PubMed

Tong, W; Kiyokawa, H; Soos, T J; Park, M S; Soares, V C; Manova, K; Pollard, J W; Koff, A

1998-09-01

The involvement of cyclin-dependent kinase inhibitors in differentiation remains unclear: are the roles of cyclin-dependent kinase inhibitors restricted to cell cycle arrest; or also required for completion of the differentiation program; or both? Here, we report that differentiation of luteal cells can be uncoupled from growth arrest in p27-deficient mice. In these mice, female-specific infertility correlates with a failure of embryos to implant at embryonic day 4.5. We show by ovarian transplant and hormone reconstitution experiments that failure to regulate luteal cell estradiol is one physiological mechanism for infertility in these mice. This failure is not due to a failure of p27-deficient granulosa cells to differentiate after hormonal stimulation; P450scc, a marker for luteal progesterone biosynthesis, is expressed and granulosa cell-specific cyclin D2 expression is reduced. However, unlike their wild-type counterparts, p27-deficient luteal cells continue to proliferate for up to 3.5 days after hormonal stimulation. By day 5.5, however, these cells withdraw from the cell cycle, suggesting that p27 plays a role in the early events regulating withdrawal of cells from the cell cycle. We have further shown that in the absence of this timely withdrawal, estradiol regulation is perturbed, explaining in part how fertility is compromised at the level of implantation. These data support the interpretation of our previous observations on oligodendrocyte differentiation about a role for p27 in establishing the nonproliferative state, which in some cases (oligodendrocytes) is required for differentiation, whereas in other cases it is required for the proper functioning of a differentiated cell (luteal cell).

The alpha-fetoprotein (AFP) third domain: a search for AFP interaction sites of cell cycle proteins.

PubMed

Mizejewski, G J

2016-09-01

The carboxy-terminal third domain of alpha-fetoprotein (AFP-3D) is known to harbor binding and/or interaction sites for hydrophobic ligands, receptors, and binding proteins. Such reports have established that AFP-3D consists of amino acid (AA) sequence stretches on the AFP polypeptide that engages in protein-to-protein interactions with various ligands and receptors. Using a computer software program specifically designed for such interactions, the present report identified AA sequence fragments on AFP-3D that could potentially interact with a variety of cell cycle proteins. The cell cycle proteins identified were (1) cyclins, (2) cyclin-dependent kinases, (3) cell cycle-associated proteins (inhibitors, checkpoints, initiators), and (4) ubiquitin ligases. Following detection of the AFP-3D to cell cycle protein interaction sites, the computer-derived AFP localization AA sequences were compared and aligned with previously reported hydrophobic ligand and receptor interaction sites on AFP-3D. A literature survey of the association of cell cycle proteins with AFP showed both positive relationships and correlations. Previous reports of experimental AFP-derived peptides effects on various cell cycle proteins served to confirm and verify the present computer cell cycle protein identifications. Cell cycle protein interactions with AFP-CD peptides have been reported in cultured MCF-7 breast cancer cells subjected to mRNA microarray analysis. After 7 days in culture with MCF-7 cells, the AFP-derived peptides were shown to downregulate cyclin E, SKP2, checkpoint suppressors, cyclin-dependent kinases, and ubiquitin ligases that modulate cyclin E/CdK2 transition from the G1 to the S-phase of the cell cycle. Thus, the experimental data on AFP-CD interaction with cell cycle proteins were consistent with the "in silico" findings.

The CDK4/6 inhibitor LY2835219 overcomes vemurafenib resistance resulting from MAPK reactivation and cyclin D1 upregulation.

PubMed

Yadav, Vipin; Burke, Teresa F; Huber, Lysiane; Van Horn, Robert D; Zhang, Youyan; Buchanan, Sean G; Chan, Edward M; Starling, James J; Beckmann, Richard P; Peng, Sheng-Bin

2014-10-01

B-RAF selective inhibitors, including vemurafenib, were recently developed as effective therapies for melanoma patients with B-RAF V600E mutation. However, most patients treated with vemurafenib eventually develop resistance largely due to reactivation of MAPK signaling. Inhibitors of MAPK signaling, including MEK1/2 inhibitor trametinib, failed to show significant clinical benefit in patients with acquired resistance to vemurafenib. Here, we describe that cell lines with acquired resistance to vemurafenib show reactivation of MAPK signaling and upregulation of cyclin D1 and are sensitive to inhibition of LY2835219, a selective inhibitor of cyclin-dependent kinase (CDK) 4/6. LY2835219 was demonstrated to inhibit growth of melanoma A375 tumor xenografts and delay tumor recurrence in combination with vemurafenib. Furthermore, we developed an in vivo vemurafenib-resistant model by continuous administration of vemurafenib in A375 xenografts. Consistently, we found that MAPK is reactivated and cyclin D1 is elevated in vemurafenib-resistant tumors, as well as in the resistant cell lines derived from these tumors. Importantly, LY2835219 exhibited tumor growth regression in a vemurafenib-resistant model. Mechanistic analysis revealed that LY2835219 induced apoptotic cell death in a concentration-dependent manner in vemurafenib-resistant cells whereas it primarily mediated cell-cycle G1 arrest in the parental cells. Similarly, RNAi-mediated knockdown of cyclin D1 induced significantly higher rate of apoptosis in the resistant cells than in parental cells, suggesting that elevated cyclin D1 activity is important for the survival of vemurafenib-resistant cells. Altogether, we propose that targeting cyclin D1-CDK4/6 signaling by LY2835219 is an effective strategy to overcome MAPK-mediated resistance to B-RAF inhibitors in B-RAF V600E melanoma. ©2014 American Association for Cancer Research.

Tangeretin induces cell-cycle G1 arrest through inhibiting cyclin-dependent kinases 2 and 4 activities as well as elevating Cdk inhibitors p21 and p27 in human colorectal carcinoma cells.

PubMed

Pan, Min-Hsiung; Chen, Wei-Jen; Lin-Shiau, Shoei-Yn; Ho, Chi-Tang; Lin, Jen-Kun

2002-10-01

Tangeretin (5,6,7,8,4'-pentamethoxyflavone) is concentrated in the peel of citrus fruits. DNA flow cytometric analysis indicated that tangeretin blocked cell cycle progression at G1 phase in colorectal carcinoma COLO 205 cells. Over a 24 h exposure to tangeretin, the degree of phosphorylation of Rb was decreased after 12 h and G1 arrest developed. The protein expression of cyclins A, D1, and E reduced slightly under the same conditions. Immunocomplex kinase experiments showed that tangeretin inhibited the activities of cyclin-dependent kinases 2 (Cdk2) and 4 (Cdk4) in a dose-dependent manner in the cell-free system. As the cells were exposed to tangeretin (50 microM) over 48 h a gradual loss of both Cdk2 and 4 kinase activities occurred. Tangeretin also increased the content of the Cdk inhibitor p21 protein and this effect correlated with the elevation in p53 levels. In addition, tangeretin also increased the level of the Cdk inhibitor p27 protein within 18 h. These results suggest that tangeretin either exerts its growth-inhibitory effects through modulation of the activities of several key G1 regulatory proteins, such as Cdk2 and Cdk4, or mediates the increase of Cdk inhibitors p21 and p27.

A c-Myc and surface CD19 signaling amplification loop promotes B cell lymphoma development and progression in mice.

PubMed

Poe, Jonathan C; Minard-Colin, Veronique; Kountikov, Evgueni I; Haas, Karen M; Tedder, Thomas F

2012-09-01

Malignant B cells responding to external stimuli are likely to gain a growth advantage in vivo. These cells may therefore maintain surface CD19 expression to amplify transmembrane signals and promote their expansion and survival. To determine whether CD19 expression influences this process, Eμ-Myc transgenic (c-Myc(Tg)) mice that develop aggressive and lethal B cell lymphomas were made CD19 deficient (c-Myc(Tg)CD19⁻/⁻). Compared with c-Myc(Tg) and c-Myc(Tg)CD19⁺/⁻ littermates, the median life span of c-Myc(Tg)CD19⁻/⁻ mice was prolonged by 81-83% (p < 0.0001). c-Myc(Tg)CD19⁻/⁻ mice also lived 42% longer than c-Myc(Tg) littermates following lymphoma detection (p < 0.01). Tumor cells in c-Myc(Tg) and c-Myc(Tg)CD19⁻/⁻ mice were B lineage derived, had a similar phenotype with a large blastlike appearance, invaded multiple lymphoid tissues, and were lethal when adoptively transferred into normal recipient mice. Importantly, reduced lymphomagenesis in c-Myc(Tg)CD19⁻/⁻ mice was not due to reductions in early B cell numbers prior to disease onset. In mechanistic studies, constitutive c-Myc expression enhanced CD19 expression and phosphorylation on active sites. Reciprocally, CD19 expression in c-Myc(Tg) B cells enhanced c-Myc phosphorylation at regulatory sites, sustained higher c-Myc protein levels, and maintained a balance of cyclin D2 expression over that of cyclin D3. These findings define a new and novel c-Myc:CD19 regulatory loop that positively influences B cell transformation and lymphoma progression.

Combinatorial strategy of epigenetic and hormonal therapies: A novel promising approach for treating advanced prostate cancer.

PubMed

Motawi, Tarek K; Darwish, Hebatallah A; Diab, Iman; Helmy, Maged W; Noureldin, Mohamed H

2018-04-01

Estrogens act as key factors in prostate biology, cellular proliferation and differentiation as well as cancer development and progression. The expression of estrogen receptor (ER)-β appears to be lost during prostate cancer progression through hypermethylation mechanism. Epigenetic drugs such as 5-aza-2'-deoxycytidine (5-AZAC) and Trichostatin A (TSA) showed efficacy in restoring ERβ expression in prostate cancer cells. This study was designed to explore the potential anti-carcinogenic effects resulting from re-expressing ERβ1 using 5-AZAC and/or TSA, followed by its stimulation with Diarylpropionitrile (DPN), a selective ERβ1 agonist, in prostate cancer cell line PC-3. Cells were treated with 5-AZAC, TSA, DPN and their combination. Subsequently, they were subjected to proliferation assays, determinations of ERβ1 expression, protein levels of active caspase-3, cyclin D1, β-catenin and VEGF. Treatment with these drugs exhibited an increase in ERβ1 expression to different extents as well as active caspase-3 levels. Meanwhile, a significant reduction in cyclin D1, VEGF and β-catenin levels was achieved as compared to the vehicle control group (p < 0.05). Interestingly, the triple combination regimen led to the most prominent anti-tumor responses in terms of increased apoptosis, reduced proliferation as well as angiogenesis. The results support the notion that ERβ1 acts as a tumor suppressor protein and suggest that sequential ERβ1 expression and activation can offer significant anti-tumor responses. The study highlights that the strategy of merging epigenetic and hormonal therapies may be beneficial in treating advanced prostate cancer. Copyright © 2018. Published by Elsevier Inc.

Liver-specific deletion of prohibitin 1 results in spontaneous liver injury, fibrosis, and hepatocellular carcinoma in mice.

PubMed

Ko, Kwang Suk; Tomasi, Maria Lauda; Iglesias-Ara, Ainhoa; French, Barbara A; French, Samuel W; Ramani, Komal; Lozano, Juan José; Oh, Pilsoo; He, Lina; Stiles, Bangyan L; Li, Tony W H; Yang, Heping; Martínez-Chantar, M Luz; Mato, José M; Lu, Shelly C

2010-12-01

Prohibitin 1 (PHB1) is a highly conserved, ubiquitously expressed protein that participates in diverse processes including mitochondrial chaperone, growth and apoptosis. The role of PHB1 in vivo is unclear and whether it is a tumor suppressor is controversial. Mice lacking methionine adenosyltransferase 1A (MAT1A) have reduced PHB1 expression, impaired mitochondrial function, and spontaneously develop hepatocellular carcinoma (HCC). To see if reduced PHB1 expression contributes to the Mat1a knockout (KO) phenotype, we generated liver-specific Phb1 KO mice. Expression was determined at the messenger RNA and protein levels. PHB1 expression in cells was varied by small interfering RNA or overexpression. At 3 weeks, KO mice exhibit biochemical and histologic liver injury. Immunohistochemistry revealed apoptosis, proliferation, oxidative stress, fibrosis, bile duct epithelial metaplasia, hepatocyte dysplasia, and increased staining for stem cell and preneoplastic markers. Mitochondria are swollen and many have no discernible cristae. Differential gene expression revealed that genes associated with proliferation, malignant transformation, and liver fibrosis are highly up-regulated. From 20 weeks on, KO mice have multiple liver nodules and from 35 to 46 weeks, 38% have multifocal HCC. PHB1 protein levels were higher in normal human hepatocytes compared to human HCC cell lines Huh-7 and HepG2. Knockdown of PHB1 in murine nontransformed AML12 cells (normal mouse hepatocyte cell line) raised cyclin D1 expression, increased E2F transcription factor binding to cyclin D1 promoter, and proliferation. The opposite occurred with PHB1 overexpression. Knockdown or overexpression of PHB1 in Huh-7 cells did not affect proliferation significantly or sensitize cells to sorafenib-induced apoptosis. Hepatocyte-specific PHB1 deficiency results in marked liver injury, oxidative stress, and fibrosis with development of HCC by 8 months. These results support PHB1 as a tumor suppressor in hepatocytes. Copyright © 2010 American Association for the Study of Liver Diseases.

1,25-DIHYDROXYVITAMIN D3 INDUCES MONOCYTIC DIFFERENTIATION OF HUMAN MYELOID LEUKEMIA CELLS BY REGULATING C/EBPβ EXPRESSION THROUGH MEF2C

PubMed Central

Zheng, Ruifang; Wang, Xuening; Studzinski, George P.

2015-01-01

Myogenic enhancer factor2 (Mef2) consists of a family of transcription factors involved in morphogenesis of skeletal, cardiac and smooth muscle cells. Among the four isoforms (Mef2A, 2B, 2C, and 2D), Mef2C was also found to play important roles in hematopoiesis. At myeloid progenitor level, Mef2C expression favors monocytic differentiation. Previous studies from our laboratory demonstrated that ERK5 was activated in 1,25-dihydroxyvitamin D3 (1,25D)-induced monocytic differentiation in AML cells and ERK5 activation was accompanied by increased Mef2C phosphorylation. We therefore examined the role of Mef2C in 1,25D-induced monocytic differentiation in AML cell lines (HL60, U937 and THP1) and found that knockdown of Mef2C with small interfering RNA (siRNA) significantly decreases the expression of the monocytic marker, CD14, without affecting the expression of the general myeloid marker, CD11b. CCAAT/Enhancer-binding protein (C/EBP) β, which can bind to CD14 promoter and increase its transcription, has been shown to be the downstream effector of 1,25D-induced monocytic differentiation in AML cells. When Mef2C was knocked down, expression of C/EBPβ was reduced at both mRNA and protein levels. The protein expression levels of cell cycle regulators, p27Kip1 and cyclin D1, were not affected by Mef2C knockdown, nor the monopoiesis related transcription factor, ATF2 (Activating Transcription Factor 2). Thus, we conclude that 1,25D-induced monocytic differentiation, and CD14 expression in particular, is mediated through activation of ERK5-Mef2C-C/EBPβ signaling pathway, and that Mef2C does not seem to modulate cell cycle progression. PMID:25448741

Mouse Mammary Tumor Virus c-rel Transgenic Mice Develop Mammary Tumors

PubMed Central

Romieu-Mourez, Raphaëlle; Kim, Dong W.; Min Shin, Sang; Demicco, Elizabeth G.; Landesman-Bollag, Esther; Seldin, David C.; Cardiff, Robert D.; Sonenshein, Gail E.

2003-01-01

Amplification, overexpression, or rearrangement of the c-rel gene, encoding the c-Rel NF-κB subunit, has been reported in solid and hematopoietic malignancies. For example, many primary human breast cancer tissue samples express high levels of nuclear c-Rel. While the Rev-T oncogene v-rel causes tumors in birds, the ability of c-Rel to transform in vivo has not been demonstrated. To directly test the role of c-Rel in breast tumorigenesis, mice were generated in which overexpression of mouse c-rel cDNA was driven by the hormone-responsive mouse mammary tumor virus long terminal repeat (MMTV-LTR) promoter, and four founder lines identified. In the first cycle of pregnancy, the expression of transgenic c-rel mRNA was observed, and levels of c-Rel protein were increased in the mammary gland. Importantly, 31.6% of mice developed one or more mammary tumors at an average age of 19.9 months. Mammary tumors were of diverse histology and expressed increased levels of nuclear NF-κB. Analysis of the composition of NF-κB complexes in the tumors revealed aberrant nuclear expression of multiple subunits, including c-Rel, p50, p52, RelA, RelB, and the Bcl-3 protein, as observed previously in human primary breast cancers. Expression of the cancer-related NF-κB target genes cyclin D1, c-myc, and bcl-xl was significantly increased in grossly normal transgenic mammary glands starting the first cycle of pregnancy and increased further in mammary carcinomas compared to mammary glands from wild-type mice or virgin transgenic mice. In transient transfection analysis in untransformed breast epithelial cells, c-Rel-p52 or -p50 heterodimers either potently or modestly induced cyclin D1 promoter activity, respectively. Lastly, stable overexpression of c-Rel resulted in increased cyclin D1 and NF-κB p52 and p50 subunit protein levels. These results indicate for the first time that dysregulated expression of c-Rel, as observed in breast cancers, is capable of contributing to mammary tumorigenesis. PMID:12897145

Endosulfan inhibiting the meiosis process via depressing expressions of regulatory factors and causing cell cycle arrest in spermatogenic cells.

PubMed

Guo, Fang-Zi; Zhang, Lian-Shuang; Wei, Jia-Liu; Ren, Li-Hua; Zhang, Jin; Jing, Li; Yang, Man; Wang, Ji; Sun, Zhi-Wei; Zhou, Xian-Qing

2016-10-01

Endosulfan is a persistent organic pollutant and widely used in agriculture as a pesticide. It is present in air, water, and soil worldwide; therefore, it is a health risk affecting especially the reproductive system. The aim of this study was to evaluate the toxicity of endosulfan in the reproductive system. To investigate the effect of endosulfan on meiosis process, 32 rats were divided into four groups, treated with 0, 1, 5, and 10 mg/kg/day endosulfan, respectively, and sacrificed after the 21 days of treatments. Results show that endosulfan caused the reductions in sperm concentration and motility rate, which resulted into an increased in sperm abnormality rate; further, endosulfan induced downregulation of spermatogenesis- and oogenesis-specific basic helix-loop-helix transcription factor (Sohlh1) which controls the switch on meiosis in mammals, as well cyclin A1, cyclin-dependent kinases 1 (CDK1), and cyclin-dependent kinases 2 (CDK2). In vitro, endosulfan induced G2/M phase arrest in the spermatogenic cell cycle and caused proliferation inhibition. Moreover, endosulfan induced oxidative stress and DNA damage in vivo and vitro. The results suggested that endosulfan could inhibit the start of meiosis by downregulating the expression of Sohlh1 and induce G2/M phase arrest of cell cycle by decreasing the expression of cyclin A1, CDK1, and CDK2 via oxidative damage, which inhibits the meiosis process, and therefore decrease the amount of sperm.

The novel agent phospho-glycerol-ibuprofen-amide (MDC-330) inhibits glioblastoma growth in mice: an effect mediated by cyclin D1

PubMed Central

Bartels, Lauren E.; Mattheolabakis, George; Vaeth, Brandon M.; LaComb, Joseph F.; Wang, Ruixue; Zhi, Jizu; Komninou, Despina; Rigas, Basil; Mackenzie, Gerardo G.

2016-01-01

Given that glioblastoma multiforme (GBM) is associated with poor prognosis, new agents are urgently needed. We developed phospho-glycerol-ibuprofen-amide (PGIA), a novel ibuprofen derivative, and evaluated its safety and efficacy in preclinical models of GBM, and its mechanism of action using human GBM cells and animal tumor models. Furthermore, we explored whether formulating PGIA in polymeric nanoparticles could enhance its levels in the brain. PGIA was 3.7- to 5.1-fold more potent than ibuprofen in suppressing the growth of human GBM cell lines. PGIA 0.75× IC50 inhibited cell proliferation by 91 and 87% in human LN-229 and U87-MG GBM cells, respectively, and induced strong G1/S arrest. In vivo, compared with control, PGIA reduced U118-MG and U87-MG xenograft growth by 77 and 56%, respectively (P < 0.05), and was >2-fold more efficacious than ibuprofen. Normal human astrocytes were resistant to PGIA, indicating selectivity. Mechanistically, PGIA reduced cyclin D1 levels in a time- and concentration-dependent manner in GBM cells and in xenografts. PGIA induced cyclin D1 degradation via the proteasome pathway and induced dephosphorylation of GSK3β, which was required for cyclin D1 turnover. Furthermore, cyclin D1 overexpression rescued GBM cells from the cell growth inhibition by PGIA. Moreover, the formulation of PGIA in poly-(l)-lactic acid poly(ethylene glycol) polymeric nanoparticles improved its pharmacokinetics in mice, delivering PGIA to the brain. PGIA displays strong efficacy against GBM, crosses the blood-brain barrier when properly formulated, reaching the target tissue, and establishes cyclin D1 as an important molecular target. Thus, PGIA merits further evaluation as a potential therapeutic option for GBM. PMID:26905586

Helicobacter pylori Induced Phosphatidylinositol-3-OH Kinase/mTOR Activation Increases Hypoxia Inducible Factor-1α to Promote Loss of Cyclin D1 and G0/G1 Cell Cycle Arrest in Human Gastric Cells.

PubMed

Canales, Jimena; Valenzuela, Manuel; Bravo, Jimena; Cerda-Opazo, Paulina; Jorquera, Carla; Toledo, Héctor; Bravo, Denisse; Quest, Andrew F G

2017-01-01

Helicobacter pylori ( H. pylori ) is a human gastric pathogen that has been linked to the development of several gastric pathologies, such as gastritis, peptic ulcer, and gastric cancer. In the gastric epithelium, the bacterium modifies many signaling pathways, resulting in contradictory responses that favor both proliferation and apoptosis. Consistent with such observations, H. pylori activates routes associated with cell cycle progression and cell cycle arrest. H. pylori infection also induces the hypoxia-induced factor HIF-1α, a transcription factor known to promote expression of genes that permit metabolic adaptation to the hypoxic environment in tumors and angiogenesis. Recently, however, also roles for HIF-1α in the repair of damaged DNA and inhibition of gene expression were described. Here, we investigated signaling pathways induced by H. pylori in gastric cells that favor HIF-1α expression and the consequences thereof in infected cells. Our results revealed that H. pylori promoted PI3K/mTOR-dependent HIF-1α induction, HIF-1α translocation to the nucleus, and activity as a transcription factor as evidenced using a reporter assay. Surprisingly, however, transcription of known HIF-1α effector genes evaluated by qPCR analysis, revealed either no change (LDHA and GAPDH), statistically insignificant increases SLC2A1 (GLUT-1) or greatly enhance transcription (VEGFA), but in an HIF-1α-independent manner, as quantified by PCR analysis in cells with shRNA-mediated silencing of HIF-1α. Instead, HIF-1α knockdown facilitated G1/S progression and increased Cyclin D1 protein half-life, via a post-translational pathway. Taken together, these findings link H. pylori -induced PI3K-mTOR activation to HIF-1α induced G0/G1 cell cycle arrest by a Cyclin D1-dependent mechanism. Thus, HIF-1α is identified here as a mediator between survival and cell cycle arrest signaling activated by H. pylori infection.

Cyclin E-Mediated Human Proopiomelanocortin Regulation as a Therapeutic Target for Cushing Disease.

PubMed

Liu, Ning-Ai; Araki, Takako; Cuevas-Ramos, Daniel; Hong, Jiang; Ben-Shlomo, Anat; Tone, Yukiko; Tone, Masahide; Melmed, Shlomo

2015-07-01

Cushing disease, due to pituitary corticotroph tumor ACTH hypersecretion, drives excess adrenal cortisol production with adverse morbidity and mortality. Loss of glucocorticoid negative feedback on the hypothalamic-pituitary-adrenal axis leads to autonomous transcription of the corticotroph precursor hormone proopiomelanocortin (POMC), consequent ACTH overproduction, and adrenal hypercortisolism. We previously reported that R-roscovitine (CYC202, seliciclib), a 2,6,9-trisubstituted purine analog, suppresses cyclin-dependent-kinase 2/cyclin E and inhibits ACTH in mice and zebrafish. We hypothesized that intrapituitary cyclin E signaling regulates corticotroph tumor POMC transcription independently of cell cycle progression. The aim was to investigate whether R-roscovitine inhibits human ACTH in corticotroph tumors by targeting the cyclin-dependent kinase 2/cyclin E signaling pathway. Primary cell cultures of surgically resected human corticotroph tumors were treated with or without R-roscovitine, ACTH measured by RIA and quantitative PCR, and/or Western blot analysis performed to investigate ACTH and lineage-specific transcription factors. Cyclin E and E2F transcription factor 1 (E2F1) small interfering RNA (siRNA) transfection was performed in murine corticotroph tumor AtT20 cells to elucidate mechanisms for drug action. POMC gene promoter activity in response to R-roscovitine treatment was analyzed using luciferase reporter and chromatin immunoprecipitation assays. R-roscovitine inhibits human corticotroph tumor POMC and Tpit/Tbx19 transcription with decreased ACTH expression. Cyclin E and E2F1 exhibit reciprocal positive regulation in corticotroph tumors. R-roscovitine disrupts E2F1 binding to the POMC gene promoter and suppresses Tpit/Tbx19 and other lineage-specific POMC transcription cofactors via E2F1-dependent and -independent pathways. R-roscovitine inhibits human pituitary corticotroph tumor ACTH by targeting the cyclin E/E2F1 pathway. Pituitary cyclin E/E2F1 signaling is a previously unappreciated molecular mechanism underlying neuroendocrine regulation of the hypothalamic-pituitary-adrenal axis, providing a subcellular therapeutic target for small molecule cyclin-dependent kinase 2 inhibitors of pituitary ACTH-dependent hypercortisolism, ie, Cushing disease.

Targeting EGF-receptor(s) - STAT1 axis attenuates tumor growth and metastasis through downregulation of MUC4 mucin in human pancreatic cancer.

PubMed

Seshacharyulu, Parthasarathy; Ponnusamy, Moorthy P; Rachagani, Satyanarayana; Lakshmanan, Imayavaramban; Haridas, Dhanya; Yan, Ying; Ganti, Apar K; Batra, Surinder K

2015-03-10

Transmembrane proteins MUC4, EGFR and HER2 are shown to be critical in invasion and metastasis of pancreatic cancer. Besides, we and others have demonstrated de novo expression of MUC4 in ~70-90% of pancreatic cancer patients and its stabilizing effects on HER2 downstream signaling in pancreatic cancer. Here, we found that use of canertinib or afatinib resulted in reduction of MUC4 and abrogation of in vitro and in vivo oncogenic functions of MUC4 in pancreatic cancer cells. Notably, silencing of EGFR family member in pancreatic cancer cells decreased MUC4 expression through reduced phospho-STAT1. Furthermore, canertinib and afatinib treatment also inhibited proliferation, migration and survival of pancreatic cancer cells by attenuation of signaling events including pERK1/2 (T202/Y204), cyclin D1, cyclin A, pFAK (Y925) and pAKT (Ser473). Using in vivo bioluminescent imaging, we demonstrated that canertinib treatment significantly reduced tumor burden (P=0.0164) and metastasis to various organs. Further, reduced expression of MUC4 and EGFR family members were confirmed in xenografts. Our results for the first time demonstrated the targeting of EGFR family members along with MUC4 by using pan-EGFR inhibitors. In conclusion, our studies will enhance the translational acquaintance of pan-EGFR inhibitors for combinational therapies to combat against lethal pancreatic cancer.

Hsa-miR-134 suppresses non-small cell lung cancer (NSCLC) development through down-regulation of CCND1

PubMed Central

Sun, Cheng-Cao; Li, Shu-Jun; Li, De-Jia

2016-01-01

Hsa-miRNA-134 (miR-134) has recently been discovered to have anticancer efficacy in different organs. However, the role of miR-134 on non-small cell lung cancer (NSCLC) is still ambiguous. In this study, we investigated the role of miR-134 on the development of NSCLC. The results indicated that miR-134 was significantly down-regulated in primary tumor tissues and very low levels were found in NSCLC cell lines. Ectopic expression of miR-134 in NSCLC cell lines significantly suppressed cell growth as evidenced by cell viability assay, colony formation assay and BrdU staining, through inhibition of cyclin D1, cyclin D2, CDK4 and up-regulation of p57(Kip2) and p21(Waf1/Cip1). In addition, miR-134 induced apoptosis, as indicated by concomitantly with up-regulation of key apoptosis protein cleaved caspase-3, and down-regulation of anti-apoptosis protein Bcl2. Moreover, miR-134 inhibited cellular migration and invasiveness through inhibition of matrix metalloproteinases (MMP)-7 and MMP-9. Further, oncogene CCND1 was revealed to be a putative target of miR-134, which was inversely correlated with miR-134 expression in NSCLC. Taken together, our results demonstrated that miR-134 played a pivotal role on NSCLC through inhibiting cell proliferation, migration, invasion, and promoting apoptosis by targeting oncogenic CCND1. PMID:27166267

Hsa-miR-326 targets CCND1 and inhibits non-small cell lung cancer development

PubMed Central

Li, Shujun; Yang, Cuili; Xi, Yongyong; Wang, Liang; Zhang, Feng; Fu, Yunfeng; Li, Dejia

2016-01-01

Hsa-miRNA-326 (miR-326) has recently been discovered having anticancer efficacy in different organs. However, the role of miR-326 on non-small cell lung cancer (NSCLC) is still ambiguous. In this study, we investigated the role of miR-326 on the development of NSCLC. The results indicated that miR-326 was significantly down-regulated in primary tumor tissues and very low levels were found in NSCLC cell lines. Ectopic expression of miR-326 in NSCLC cell lines significantly suppressed cell growth as evidenced by cell viability assay, colony formation assay and BrdU staining, through inhibition of cyclin D1, cyclin D2, CDK4 and up-regulation of p57(Kip2) and p21(Waf1/Cip1). In addition, miR-326 induced apoptosis, as indicated by concomitantly with up-regulation of key apoptosis protein cleaved caspase-3, and down-regulation of anti-apoptosis protein Bcl2. Moreover, miR-326 inhibited cellular migration and invasiveness through inhibition of matrix metalloproteinases (MMP)-7 and MMP-9. Further, oncogene CCND1 was revealed to be a putative target of miR-326, which was inversely correlated with miR-326 expression in NSCLC. Taken together, our results demonstrated that miR-326 played a pivotal role on NSCLC through inhibiting cell proliferation, migration, invasion, and promoting apoptosis by targeting oncogenic CCND1. PMID:26840018

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pang, Xiaojuan; Shu, Yuxin; Niu, Zhiyuan

Post-translational regulation plays a critical role in the control of cell growth and proliferation. The phosphorylation of peroxisome proliferator-activated receptor γ (PPARγ) is the most important post-translational modification. The function of PPARγ phosphorylation has been studied extensively in the past. However, the relationship between phosphorylated PPARγ1 and tumors remains unclear. Here we investigated the role of PPARγ1 phosphorylation in human fibrosarcoma HT1080 cell line. Using the nonphosphorylation (Ser84 to alanine, S84A) and phosphorylation (Ser84 to aspartic acid, S84D) mutant of PPARγ1, the results suggested that phosphorylation attenuated PPARγ1 transcriptional activity. Meanwhile, we demonstrated that phosphorylated PPARγ1 promoted HT1080 cell proliferationmore » and this effect was dependent on the regulation of cell cycle arrest. The mRNA levels of cyclin-dependent kinase inhibitor (CKI) p21{sup Waf1/Cip1} and p27{sup Kip1} descended in PPARγ1{sup S84D} stable HT1080 cell, whereas the expression of p18{sup INK4C} was not changed. Moreover, compared to the PPARγ1{sup S84A}, PPARγ1{sup S84D} up-regulated the expression levels of cyclin D1 and cyclin A. Finally, PPARγ1 phosphorylation reduced sensitivity to agonist rosiglitazone and increased resistance to anticancer drug 5-fluorouracil (5-FU) in HT1080 cell. Our findings establish PPARγ1 phosphorylation as a critical event in human fibrosarcoma growth. These findings raise the possibility that chemical compounds that prevent the phosphorylation of PPARγ1 could act as anticancer drugs. - Highlights: • Phosphorylation attenuates PPARγ1 transcriptional activity. • Phosphorylated PPARγ1 promotes HT1080 cells proliferation. • PPARγ1 phosphorylation regulates cell cycle by mediating expression of cell cycle regulators. • PPARγ1 phosphorylation reduces sensitivity to agonist and anticancer drug. • Our findings establish PPARγ1 phosphorylation as a critical event in HT1080 cells growth.« less

Assessment of anti-cancerous potential of 6-gingerol (Tongling White Ginger) and its synergy with drugs on human cervical adenocarcinoma cells.

PubMed

Zhang, Fang; Zhang, Jian-Guo; Qu, Jie; Zhang, Qi; Prasad, Chandan; Wei, Zhao-Jun

2017-11-01

The anti-cancerous activity of 6-gingerol extracted from Tongling White Ginger was investigated. 6-Gingerol inhibited the growth of HeLa cells with IC50 (96.32 μM) and IC80 (133.01 μM) and led to morphological changes, induced the cell cycle arrest in G0/G1-phase and ultimately resulted into apoptosis. Among cell cycle-related genes and proteins, the expression of cyclin (A, D1, E1) reduced, while of CDK-1, p21 and p27 showed slight decrease, except cyclin B1 and E1 (protein). Western blotting reported the induction of apoptosis with an increased Bax/Bcl-2 ratio, release of cytochrome c, cleavage of caspase-3, -8, -9 and PRPP in treated cells. 6-Gingerol activated AMPK, but inhibited PI3K/AKT phosphorylation with reduced P70S6K expression and also suppressed the mTOR phosphorylation. 6-Gingerol with 5-FU and Ptx resulted in 83.2% and 52% inhibition respectively, this synergy have stimulated apoptosis proteins more efficiently as compared to 6-Gingerol alone (10.75%) under in vitro conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Expression of genomic AtCYCD2;1 in Arabidopsis induces cell division at smaller cell sizes: implications for the control of plant growth.

PubMed

Qi, Ruhu; John, Peter Crook Lloyd

2007-07-01

The Arabidopsis (Arabidopsis thaliana) CYCD2;1 gene introduced in genomic form increased cell formation in the Arabidopsis root apex and leaf, while generating full-length mRNA, raised CDK/CYCLIN enzyme activity, reduced G1-phase duration, and reduced size of cells at S phase and division. Other cell cycle genes, CDKA;1, CYCLIN B;1, and the cDNA form of CYCD2;1 that produced an aberrantly spliced mRNA, produced smaller or zero increases in CDK/CYCLIN activity and did not increase the number of cells formed. Plants with a homozygous single insert of genomic CYCD2;1 grew with normal morphology and without accelerated growth of root or shoot, not providing evidence that cell formation or CYCLIN D2 controls growth of postembryonic vegetative tissues. At the root apex, cells progressed normally from meristem to elongation, but their smaller size enclosed less growth and a 40% reduction in final size of epidermal and cortical cells was seen. Smaller elongated cell size inhibited endoreduplication, indicating a cell size requirement. Leaf cells were also smaller and more numerous during proliferation and epidermal pavement and palisade cells attained 59% and 69% of controls, whereas laminas reached normal size. Autonomous control of expansion was therefore not evident in abundant cell types that formed tissues of root or leaf. Cell size was reduced by a greater number formed in a tissue prior to cell and tissue expansion. Initiation and termination of expansion did not correlate with cell dimension or number and may be determined by tissue-wide signals acting across cellular boundaries.

Effect of GSK-3 inhibitor on the proliferation of multipotent male germ line stem cells (mGSCs) derived from goat testis.

PubMed

Zhu, H; Liu, C; Sun, J; Li, M; Hua, J

2012-06-01

The glycogen synthase kinase 3 (GSK3) inhibitor, 6-bromoindirubin-3'-oxime (BIO), is a key regulator of many signaling pathways to maintain pluripotency of human and mouse embryonic stem cells (ESCs). However, the effect of BIO on derivation of dairy goat male germline stem cells (mGSCs) remains unclear. The objectives of this study were to investigate whether BIO influences derivation of dairy goat mGSCs. Dairy goat mGSCs were cultured in mTeSR containing BIO medium and its effects on the proliferation ability of goat mGSCs (derived from goats ≤2 mo of age) were evaluated by 5-Bromo-2-deoxyuridine (BrdU) incorporation and alkaline phosphatase (AP) staining. Furthermore, its effects on maintenance of the undifferentiated state of mGSCs in late passages of cultures, as well as the capacity of mGSCs to differentiate into embryoid bodies (EBs) were examined. The presence of BIO increased the mitosis index and the number of AP positive colonies, as well as expression of pluripotent markers, Oct4, Nanog, Sox2, C-myc, Klf4, E-cadherin, and the proliferative markers, Pcna and C-myc. In contrast, there was no significant change in expression of apoptosis markers, P53, P21 and cyclin-related genes (Cyclin A, CDK2, Cyclin D1), as determined by RT-PCR analysis. When mGSCs were cultured in mTeSR medium containing BIO, EBs were formed, which were capable of further differentiating into various cell types found in the three embryonic germ layers, as determined by immunofluorescence and/or histologic staining. In conclusion, adding BIO to cultures BIO significantly promoted establishment of goat mGSC colonies and maintained their undifferentiated state. Copyright © 2012 Elsevier Inc. All rights reserved.

Inducing myoblast re-entry into the cell cycle: a potential mechanism for laser-enhanced skeletal muscle regeneration

NASA Astrophysics Data System (ADS)

Liu, T.; Fang, Y.; Zhang, C. P.; Chen, P.; Wang, C. Z.; Kang, H. X.; Shen, B. J.; Liang, J.; Fu, X. B.

2014-09-01

This study investigated the effect of low-level laser irradiation (LLLI) on the cell cycle and proliferative activity of cultured myoblasts, and sought to elucidate the possible cellular mechanism by which LLLI promotes the regeneration of skeletal muscle in vivo. Primary myoblasts isolated from rat hindlegs were irradiated with helium-neon laser light at different energy densities. Distributions of cell-cycle subpopulations and the expression of cell-cycle regulatory proteins in myoblasts were assessed using flow cytometric analysis and western blot assay. It was found that laser irradiation stimulated cell-cycle entry; induced the expression of cyclin A and cyclin D; and increased cell proliferation index and bromodeoxyuridine incorporation as compared to the unirradiated control cells, indicating LLLI augmented the number of proliferative myoblasts in the S phase and G2/M phase of the cell cycle. These results suggest that LLLI at certain fluxes and wavelengths could activate quiescent myoblasts, leading to cell division and facilitating new myofiber formation. This could contribute to the improvement of skeletal muscle regeneration following trauma and myopathic diseases.

Human breast tissue disposition and bioactivity of limonene in women with early stage breast cancer

PubMed Central

Miller, Jessica A.; Lang, Julie E.; Ley, Michele; Nagle, Ray; Hsu, Chiu-Hsieh; Thompson, Patricia A; Cordova, Catherine; Waer, Amy; Chow, H.-H. Sherry

2013-01-01

Limonene is a bioactive food component found in citrus peel oil that has demonstrated chemopreventive and chemotherapeutic activities in preclinical studies. We conducted an open label pilot clinical study to determine the human breast tissue disposition of limonene and its associated bioactivity. We recruited forty-three women with newly diagnosed operable breast cancer electing to undergo surgical excision to take 2 grams of limonene daily for 2 – 6 weeks before surgery. Blood and breast tissue were collected to determine drug/metabolite concentrations and limonene-induced changes in systemic and tissue biomarkers of breast cancer risk or carcinogenesis. Limonene was found to preferentially concentrate in the breast tissue, reaching high tissue concentration (mean=41.3 μg/g tissue) while the major active circulating metabolite, perillic acid, did not concentrate in the breast tissue. Limonene intervention resulted in a 22% reduction in cyclin D1 expression (P=0.002) in tumor tissue but minimal changes in tissue Ki67 and cleaved caspase 3 expression. No significant changes in serum leptin, adiponectin, TGF-β1, IGFBP-3 and IL-6 levels were observed following limonene intervention. There was a small but statistically significant post-intervention increase in IGF-1 levels. We conclude that limonene distributed extensively to human breast tissue and reduced breast tumor cyclin D1 expression that may lead to cell cycle arrest and reduced cell proliferation. Further placebo-controlled clinical trials and translational research are warranted to establish limonene’s role for breast cancer prevention or treatment. PMID:23554130

Growth retardation induced by avian leukosis virus subgroup J associated with down-regulated Wnt/β-catenin pathway.

PubMed

Feng, Weiguo; Zhou, Defang; Meng, Wei; Li, Gen; Zhuang, Pingping; Pan, Zhifang; Wang, Guihua; Cheng, Ziqiang

2017-03-01

Avian leukosis virus subgroup J (ALV-J), an oncogenic retrovirus, induces growth retardation and neoplasia in chickens, leading to enormous economic losses in poultry industry. Increasing evidences showed several signal pathways involved in ALV-J infection. However, what signaling pathway involved in growth retardation is largely unknown. To explore the possible signaling pathway, we tested the cell proliferation and associated miRNAs in ALV-J infected CEF cells by CCK-8 and Hiseq, respectively. The results showed that cell proliferation was significantly inhibited by ALV-J and three associated miRNAs were identified to target Wnt/β-catenin pathway. To verify the Wnt/β-catenin pathway involved in cell growth retardation, we analyzed the key molecules of Wnt pathway in ALV-J infected CEF cells. Our data demonstrated that protein expression of β-catenin was decreased significantly post ALV-J infection compared with the normal (P < 0.05). The impact of this down-regulation caused low expression of known target genes (Axin2, CyclinD1, Tcf4 and Lef1). Further, to obtain in vivo evidence, we set up an ALV-J infection model. Post 7 weeks infection, ALV-J infected chickens showed significant growth retardation. Subsequent tests showed that the expression of β-catenin, Tcf1, Tcf4, Lef1, Axin2 and CyclinD1 were down-regulated in muscles of growth retardation chickens. Taken together, all data demonstrated that chicken growth retardation caused by ALV-J associated with down-regulated Wnt/β-catenin signaling pathway. Copyright © 2017 Elsevier Ltd. All rights reserved.

Differential expression of miR16 in glioblastoma and glioblastoma stem cells: their correlation with proliferation, differentiation, metastasis and prognosis

PubMed Central

Tian, R; Wang, J; Yan, H; Wu, J; Xu, Q; Zhan, X; Gui, Z; Ding, M; He, J

2017-01-01

The function of miR16 in multiforme glioblastoma multiforme (GBM) and its stem cells (GSCs) remains elusive. To this end, we investigated the patterns of miR16 expression in these cells and their correlation with malignant behaviors and clinical outcomes. The levels of miR16 and its targeted genes in tumor tissue of GBM and GBM SGH44, U87, U251 cells as well as their stem cell counterparts were measured by qRT–PCR or western blot or immunohistochemistry. Luciferase reporter assay was used to confirm the binding of miR16 to 3′-UTR of its target genes. The effects of miR16 on malignant behaviors were investigated, including tumor cell viability, soft-agar colony formation, GSCs Matrigel colony forming and migration and invasion as well as nude mice xenograft model. Differentially expression patterns of miR16 in glioblastoma cells and GSCs cells were found in this study. Changes of miR16 targeted genes, Bcl2 (B cell lymphoma 2), CDK6 (Cyclin-dependent kinase 6), CCND1 (cyclin D1), CCNE1 (cyclin E1) and SOX5 were confirmed in glioblastoma cell lines and tissue specimens. In vitro and in vivo studies showed that tumor cell proliferation was inhibited by miR16 mimic, but enhanced by miR16 inhibitor. The expression level of miR16 positively correlates with GSCs differentiation, but negatively with the abilities of migration, motility, invasion and colony formation in glioblastoma cells. The inhibitory effects of miR16 on its target genes were also found in nude mice xenograft model. Our findings revealed that the miR16 functions as a tumor suppressor in GSCs and its association with prognosis in GBM. PMID:28628119

Downregulation of Ubiquitin-conjugating Enzyme UBE2D3 Promotes Telomere Maintenance and Radioresistance of Eca-109 Human Esophageal Carcinoma Cells

PubMed Central

Yang, Hui; Wu, Lin; Ke, Shaobo; Wang, Wenbo; Yang, Lei; Gao, Xiaojia; Fang, Hongyan; Yu, Haijun; Zhong, Yahua; Xie, Conghua; Zhou, Fuxiang; Zhou, Yunfeng

2016-01-01

Ubiquitin-conjugating enzyme UBE2D3 is an important member of the ubiquitin-proteasome pathways. Our previous study showed that the expression of UBE2D3 was negatively related to human telomerase reverse transcriptase (hTERT) and radioresistance in human breast cancer cells. However, in esophageal carcinoma, the exact effects and mechanisms of UBE2D3 in radioresistance remain unclear. This study shows that UBE2D3 knockdown was associated with significant increases in radioresistance to X-rays, telomerase activity, telomere length, and telomere shelterins. UBE2D3 knockdown-mediated radioresistance was related to a decrease in the spontaneous and ionizing radiation-induced apoptosis, resulting from a decrease in the Bax/Bcl-2 ratio. Furthermore, UBE2D3 downregulation was associated with increased G1-S phase transition and prolonged IR-induced G2/M arrest through over expression of cyclin D1, decrease of CDC25A expression and promotion of the ATM/ATR-Chk1-CDC25C pathway. Moreover, UBE2D3 downregulation reduced spontaneous DNA double-strand breaks and accelerated the repair of DNA damage induced by IR. The current data thus demonstrate that UBE2D3 downregulation enhances radioresistance by increased telomere homeostasis and prolonged IR-induced G2/M arrest, but decreases the IR-induced apoptosis and the number of DNA damage foci. These results suggest that UBE2D3 might be a potential molecular target to improve radiotherapy effects in esophageal carcinoma. PMID:27326259

Hypoxia induces pulmonary fibroblast proliferation through NFAT signaling.

PubMed

Senavirathna, Lakmini Kumari; Huang, Chaoqun; Yang, Xiaoyun; Munteanu, Maria Cristina; Sathiaseelan, Roshini; Xu, Dao; Henke, Craig A; Liu, Lin

2018-02-09

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive and typically fatal lung disease with a very low survival rate. Excess accumulation of fibroblasts, myofibroblasts and extracellular matrix creates hypoxic conditions within the lungs, causing asphyxiation. Hypoxia is, therefore, one of the prominent features of IPF. However, there have been few studies concerning the effects of hypoxia on pulmonary fibroblasts. In this study, we investigated the molecular mechanisms of hypoxia-induced lung fibroblast proliferation. Hypoxia increased the proliferation of normal human pulmonary fibroblasts and IPF fibroblasts after exposure for 3-6 days. Cell cycle analysis demonstrated that hypoxia promoted the G1/S phase transition. Hypoxia downregulated cyclin D1 and A2 levels, while it upregulated cyclin E1 protein levels. However, hypoxia had no effect on the protein expression levels of cyclin-dependent kinase 2, 4, and 6. Chemical inhibition of hypoxia-inducible factor (HIF)-2 reduced hypoxia-induced fibroblast proliferation. Moreover, silencing of Nuclear Factor Activated T cell (NFAT) c2 attenuated the hypoxia-mediated fibroblasts proliferation. Hypoxia also induced the nuclear translocation of NFATc2, as determined by immunofluorescence staining. NFAT reporter assays showed that hypoxia-induced NFAT signaling activation is dependent on HIF-2, but not HIF-1. Furthermore, the inhibition or silencing of HIF-2, but not HIF-1, reduced the hypoxia-mediated NFATc2 nuclear translocation. Our studies suggest that hypoxia induces the proliferation of human pulmonary fibroblasts through NFAT signaling and HIF-2.

Role of Pin1 in UVA-induced cell proliferation and malignant transformation in epidermal cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Chang Yeob; Hien, Tran Thi; Lim, Sung Chul

2011-06-24

Highlights: {yields} Pin1 expression is enhanced by low energy UVA irradiation in both skin tissues of hairless mice and JB6 C141 epidermal cells. {yields} UVA irradiation increases activator protein-1 activity and cyclin D1 in a Pin1-dependent manner. {yields} UVA potentiates EGF-inducible, anchorage-independent growth of epidermal cells, and this is suppressed by Pin1 inhibition or by anti-oxidant. -- Abstract: Ultraviolet A (UVA) radiation ({lambda} = 320-400 nm) is considered a major cause of human skin cancer. Pin1, a peptidyl prolyl isomerase, is overexpressed in most types of cancer tissues and plays an important role in cell proliferation and transformation. Here, wemore » demonstrated that Pin1 expression was enhanced by low energy UVA (300-900 mJ/cm{sup 2}) irradiation in both skin tissues of hairless mice and JB6 C141 epidermal cells. Exposure of epidermal cells to UVA radiation increased cell proliferation and cyclin D1 expression, and these changes were blocked by Pin1 inhibition. UVA irradiation also increased activator protein-1 (AP-1) minimal reporter activity and nuclear levels of c-Jun, but not c-Fos, in a Pin1-dependent manner. The increases in Pin1 expression and in AP-1 reporter activity in response to UVA were abolished by N-acetylcysteine (NAC) treatment. Finally, we found that pre-exposure of JB6 C141 cells to UVA potentiated EGF-inducible, anchorage-independent growth, and this effect was significantly suppressed by Pin1inhibition or by NAC.« less

Therapeutic suppression of translation initiation factor eIF4E expression reduces tumor growth without toxicity

PubMed Central

Graff, Jeremy R.; Konicek, Bruce W.; Vincent, Thomas M.; Lynch, Rebecca L.; Monteith, David; Weir, Spring N.; Schwier, Phil; Capen, Andrew; Goode, Robin L.; Dowless, Michele S.; Chen, Yuefeng; Zhang, Hong; Sissons, Sean; Cox, Karen; McNulty, Ann M.; Parsons, Stephen H.; Wang, Tao; Sams, Lillian; Geeganage, Sandaruwan; Douglass, Larry E.; Neubauer, Blake Lee; Dean, Nicholas M.; Blanchard, Kerry; Shou, Jianyong; Stancato, Louis F.; Carter, Julia H.; Marcusson, Eric G.

2007-01-01

Expression of eukaryotic translation initiation factor 4E (eIF4E) is commonly elevated in human and experimental cancers, promoting angiogenesis and tumor growth. Elevated eIF4E levels selectively increase translation of growth factors important in malignancy (e.g., VEGF, cyclin D1) and is thereby an attractive anticancer therapeutic target. Yet to date, no eIF4E-specific therapy has been developed. Herein we report development of eIF4E-specific antisense oligonucleotides (ASOs) designed to have the necessary tissue stability and nuclease resistance required for systemic anticancer therapy. In mammalian cultured cells, these ASOs specifically targeted the eIF4E mRNA for destruction, repressing expression of eIF4E-regulated proteins (e.g., VEGF, cyclin D1, survivin, c-myc, Bcl-2), inducing apoptosis, and preventing endothelial cells from forming vessel-like structures. Most importantly, intravenous ASO administration selectively and significantly reduced eIF4E expression in human tumor xenografts, significantly suppressing tumor growth. Because these ASOs also target murine eIF4E, we assessed the impact of eIF4E reduction in normal tissues. Despite reducing eIF4E levels by 80% in mouse liver, eIF4E-specific ASO administration did not affect body weight, organ weight, or liver transaminase levels, thereby providing the first in vivo evidence that cancers may be more susceptible to eIF4E inhibition than normal tissues. These data have prompted eIF4E-specific ASO clinical trials for the treatment of human cancers. PMID:17786246

Basic anatomy and tumor biology of the RPS6KA6 gene that encodes the p90 ribosomal S6 kinase-4

PubMed Central

Sun, Yuan; Cao, Shousong; Yang, Min; Wu, Sihong; Wang, Zhe; Lin, Xiukun; Song, Xiangrang; Liao, D.J.

2012-01-01

The RPS6KA6 gene encodes the p90 ribosomal S6 kinase-4 (RSK4) that is still largely uncharacterized. In this study we identified a new RSK4 transcription initiation site and several alternative splice sites with a 5’RACE approach. The resulting mRNA variants encompass four possible first start codons. The first 15 nucleotides (nt) of exon 22 in mouse and the penultimate exon in both human (exon 21) and mouse (exon 24) RSK4 underwent alternative splicing, although the penultimate exon deleted variant appeared mainly in cell clines, but not in most normal tissues. Demethylation agent 5-azacytidine inhibited the deletion of the penultimate exon whereas two indolocarbazole-derived inhibitors of cyclin dependent kinase 4 or 6 induced deletion of the first 39 nt from exon 21 of human RSK4. In all human cancer cell lines studied, the 90-kD wild type RSK4 was sparse but, surprisingly, several isoforms at or smaller than 72-kD were expressed as detected by seven different antibodies. On immunoblots, each of these smaller isoforms often appeared as a duplet or triplet and the levels of these isoforms varied greatly among different cell lines and culture conditions. Cyclin D1 inhibited RSK4 expression and serum starvation enhanced the inhibition, whereas c-Myc and RSK4 inhibited cyclin D1. The effects of RSK4 on cell growth, cell death and chemoresponse depended on the mRNA variant or the protein isoform expressed, on the specificity of the cell lines, as well as on the anchorage-dependent or -independent growth conditions and the in vivo situation. Moreover, we also observed that even a given cDNA might be expressed to multiple proteins; therefore, when using a cDNA, one needs to exclude this possibility before attribution of the biological results from the cDNA to the anticipated protein. Collectively, our results suggest that whether RSK4 is oncogenic or tumor suppressive depends on many factors. PMID:22614021