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Sample records for cyclin d1 transcription

  1. Transcriptional role of cyclin D1 in development revealed by a “genetic-proteomic” screen

    PubMed Central

    Bienvenu, Frédéric; Jirawatnotai, Siwanon; Elias, Joshua E.; Meyer, Clifford A.; Mizeracka, Karolina; Marson, Alexander; Frampton, Garrett M.; Cole, Megan F.; Odom, Duncan T.; Odajima, Junko; Geng, Yan; Zagozdzon, Agnieszka; Jecrois, Marie; Young, Richard A.; Liu, X. Shirley; Cepko, Constance L.; Gygi, Steven P.; Sicinski, Piotr

    2010-01-01

    Cyclin D1 belongs to the core cell cycle machinery, and it is frequently overexpressed in human cancers1,2. The full repertoire of cyclin D1 functions in normal development and in oncogenesis is currently unclear. Here we developed FLAG- and HA-tagged cyclin D1 knock-in mouse strains that allowed high-throughput mass spectrometry approach to search for cyclin D1-binding proteins in different mouse organs. In addition to cell cycle partners, we observed several proteins involved in transcription. Genome-wide location (ChIP-chip) analyses revealed that during mouse development cyclin D1 occupies promoters of abundantly expressed genes. In particular, we found that in developing mouse retinas – an organ that critically requires cyclin D1 function3,4 – cyclin D1 binds the upstream regulatory region of the Notch1 gene where it serves to recruit CBP histone acetyltransferase. Genetic ablation of cyclin D1 resulted in decreased CBP recruitment, decreased histone acetylation of the Notch1 promoter region, and led to decreased levels of the Notch transcript and protein in cyclin D1-null retinas. Transduction of an activated allele of Notch1 into cyclin D1−/− retinas increased proliferation of retinal progenitor cells, indicating that upregulating Notch1 signaling alleviates the phenotype of cyclin D1-deficiency. These studies reveal that in addition to its well-established cell cycle roles, cyclin D1 plays an in vivo transcriptional function in mouse development. Our approach, which we term “genetic-proteomic” can be used to study the in vivo function of essentially any protein. PMID:20090754

  2. Telomerase activates transcription of cyclin D1 gene through an interaction with NOL1.

    PubMed

    Hong, Juyeong; Lee, Ji Hoon; Chung, In Kwon

    2016-04-15

    Telomerase is a ribonucleoprotein enzyme that is required for the maintenance of telomere repeats. Although overexpression of telomerase in normal human somatic cells is sufficient to overcome replicative senescence, the ability of telomerase to promote tumorigenesis requires additional activities that are independent of its role in telomere extension. Here, we identify proliferation-associated nucleolar antigen 120 (NOL1, also known as NOP2) as a telomerase RNA component (TERC)-binding protein that is found in association with catalytically active telomerase. Although NOL1 is highly expressed in the majority of human tumor cells, the molecular mechanism by which NOL1 contributes to tumorigenesis remained unclear. We show that NOL1 binds to the T-cell factor (TCF)-binding element of the cyclin D1 promoter and activates its transcription. Interestingly, telomerase is also recruited to the cyclin D1 promoter in a TERC-dependent manner through the interaction with NOL1, further enhancing transcription of the cyclin D1 gene. Depletion of NOL1 suppresses cyclin D1 promoter activity, thereby leading to induction of growth arrest and altered cell cycle distributions. Collectively, our findings suggest that NOL1 represents a new route by which telomerase activates transcription of cyclin D1 gene, thus maintaining cell proliferation capacity. © 2016. Published by The Company of Biologists Ltd.

  3. IKKα Regulates Mitogenic Signaling through Transcriptional Induction of Cyclin D1 via Tcf

    PubMed Central

    Albanese, Chris; Wu, Kongming; D'Amico, Mark; Jarrett, Christy; Joyce, David; Hughes, Julian; Hulit, James; Sakamaki, Toshiyuki; Fu, Maofu; Ben-Ze'ev, Avri; Bromberg, Jacqueline F.; Lamberti, Carmela; Verma, Udit; Gaynor, Richard B.; Byers, Stephen W.; Pestell, Richard G.

    2003-01-01

    The Wnt/β-catenin/Tcf and IκB/NF-κB cascades are independent pathways involved in cell cycle control, cellular differentiation, and inflammation. Constitutive Wnt/β-catenin signaling occurs in certain cancers from mutation of components of the pathway and from activating growth factor receptors, including RON and MET. The resulting accumulation of cytoplasmic and nuclear β-catenin interacts with the Tcf/LEF transcription factors to induce target genes. The IκB kinase complex (IKK) that phosphorylates IκB contains IKKα, IKKβ, and IKKγ. Here we show that the cyclin D1 gene functions as a point of convergence between the Wnt/β-catenin and IκB pathways in mitogenic signaling. Mitogenic induction of G1-S phase progression and cyclin D1 expression was PI3K dependent, and cyclin D1−/− cells showed reduced PI3K-dependent S-phase entry. PI3K-dependent induction of cyclin D1 was blocked by inhibitors of PI3K/Akt/IκB/IKKα or β-catenin signaling. A single Tcf site in the cyclin D1 promoter was required for induction by PI3K or IKKα. In IKKα−/− cells, mitogen-induced DNA synthesis, and expression of Tcf-responsive genes was reduced. Reintroduction of IKKα restored normal mitogen induction of cyclin D1 through a Tcf site. In IKKα−/− cells, β-catenin phosphorylation was decreased and purified IKKα was sufficient for phosphorylation of β-catenin through its N-terminus in vitro. Because IKKα but not IKKβ induced cyclin D1 expression through Tcf activity, these studies indicate that the relative levels of IKKα and IKKβ may alter their substrate and signaling specificities to regulate mitogen-induced DNA synthesis through distinct mechanisms. PMID:12589056

  4. Synergistic cooperation of Sall4 and Cyclin D1 in transcriptional repression

    SciTech Connect

    Boehm, Johann; Kaiser, Frank J.; Borozdin, Wiktor; Depping, Reinhard; Kohlhase, Juergen . E-mail: jkohlhase@humangenetik-freiburg.de

    2007-05-11

    Loss of function mutations in SALL4 cause Okihiro syndrome, an autosomal dominant disorder characterised by radial ray malformations associated with Duane anomaly. In zebrafish and mouse Sall4 interacts with TBX5 during limb and heart development and plays a crucial role for embryonic stem (ES) cell pluripotency. Here we report the nuclear interaction of murine Sall4 with Cyclin D1, one of the main regulators of G{sub 1} to S phase transition in cell cycle, verified by yeast two-hybrid assay, co-immunoprecipitation and intracellular co-localisation. Furthermore, using luciferase reporter gene assays we demonstrate that Sall4 operates as a transcriptional repressor located to heterochromatin and that this activity is modulated by Cyclin D1.

  5. The HTLV-1 HBZ protein inhibits cyclin D1 expression through interacting with the cellular transcription factor CREB.

    PubMed

    Ma, Yunyun; Zheng, Shangen; Wang, Yuanyuan; Zang, Wenqiao; Li, Min; Wang, Na; Li, Ping; Jin, Jing; Dong, Ziming; Zhao, Guoqiang

    2013-10-01

    Human T cell leukemia virus type 1 (HTLV-1) is an oncogenic retrovirus that can cause adult T-cell leukemia (ATL) and other diseases. The HTLV-1 bZIP factor (HBZ), which is encoded by an mRNA of the opposite polarity of the viral genomic RNA, interacts with several transcription factors and is involved in T cell proliferation, viral gene transcription and cellular transformation. Cyclin D1 is a pivotal regulatory protein involved in cell cycle progression, and its depressed expression correlates with cell cycle prolongation or arrested at the G1/S transition. In our present study, we observed that HBZ expression suppressed cyclin D1 level. To investigate the role of HBZ on cyclin D1 depression, we transduced HBZ with lentivirus vector into 293T cells, CEM cells and Jurkat cells. The results of Western blot, RT-PCR and luciferase assays showed that transcriptional activity of the cyclin D1 promoter was suppressed by the bZIP domain of HBZ (HBZ-bZIP) through cyclic AMP response element (CRE) site. Immunoprecipitation and GST pull-down assays showed the binding of HBZ-bZIP to CRE-binding protein (CREB), which confirmed that the cyclin D1 promoter activity inhibition via the CRE-site was mediated by HBZ-bZIP. The results suggested that HBZ suppressed cyclin D1 transcription through interactions with CREB and along with other viral protein, HBZ may play a causal role for leukemogenesis.

  6. Progesterone Receptor–Cyclin D1 Complexes Induce Cell Cycle–Dependent Transcriptional Programs in Breast Cancer Cells

    PubMed Central

    Dressing, Gwen E.; Knutson, Todd P.; Schiewer, Matthew J.; Daniel, Andrea R.; Hagan, Christy R.; Diep, Caroline H.; Knudsen, Karen E.

    2014-01-01

    The progesterone receptor (PR) and its coactivators are direct targets of activated cyclin-dependent kinases (CDKs) in response to peptide growth factors, progesterone, and deregulation of cell cycle inhibitors. Herein, using the T47D breast cancer model, we probed mechanisms of cell cycle–dependent PR action. In the absence of exogenous progestin, the PR is specifically phosphorylated during the G2/M phase. Accordingly, numerous PR target genes are cell cycle regulated, including HSPB8, a heat-shock protein whose high expression is associated with tamoxifen resistance. Progestin-induced HSPB8 expression required cyclin D1 and was insensitive to antiestrogens but blocked by antiprogestins or inhibition of specificity factor 1 (SP1). HSPB8 expression increased with or without ligand when cells were G2/M synchronized or contained high levels of cyclin D1. Knockdown of PRs abrogated ligand-independent HSPB8 expression in synchronized cells. Notably, PRs and cyclin D1 copurified in whole-cell lysates of transiently transfected COS-1 cells and in PR-positive T47D breast cancer cells expressing endogenous cyclin D1. PRs, cyclin D1, and SP1 were recruited to the HSPB8 promoter in progestin-treated T47D breast cancer cells. Mutation of PR Ser345 to Ala (S345A) or inhibition of CDK2 activity using roscovitine disrupted PR/cyclin D1 interactions with DNA and blocked HSPB8 mRNA expression. Interaction of phosphorylated PRs with SP1 and cyclin D1 provides a mechanism for targeting transcriptionally active PRs to selected gene promoters relevant to breast cancer progression. Understanding the functional linkage between PRs and cell cycle regulatory proteins will provide keys to targeting novel PR/cyclin D1 cross talk in both hormone-responsive disease and HSPB8-high refractory disease with high HSPB8 expression. PMID:24606123

  7. PKCα TUMOR SUPPRESSION IN THE INTESTINE IS ASSOCIATED WITH TRANSCRIPTIONAL AND TRANSLATIONAL INHIBITION OF CYCLIN D1

    PubMed Central

    Pysz, Marybeth A.; Leontieva, Olga V.; Bateman, Nicholas W.; Uronis, Joshua M.; Curry, Kathryn J.; Threadgill, David W.; Janssen, Klaus-Peter; Robine, Sylvie; Velcich, Anna; Augenlicht, Leonard; Black, Adrian R.; Black, Jennifer D.

    2009-01-01

    Alterations in PKC isozyme expression and aberrant induction of cyclin D1 are early events in intestinal tumorigenesis. Previous studies have identified cyclin D1 as a major target in the antiproliferative effects of PKCα in non-transformed intestinal cells; however, a link between PKC signaling and cyclin D1 in colon cancer remained to be established. The current study further characterized PKC isozyme expression in intestinal neoplasms and explored the consequences of restoring PKCα or PKCδ in a panel of colon carcinoma cell lines. Consistent with patterns of PKC expression in primary tumors, PKCα and δ levels were generally reduced in colon carcinoma cell lines, PKCβII was elevated and PKCε showed variable expression, thus establishing the suitability of these models for analysis of PKC signaling. While colon cancer cells were insensitive to the effects of PKC agonists on cyclin D1 levels, restoration of PKCα downregulated cyclin D1 by two independent mechanisms. PKCα expression consistently (a) reduced steady-state levels of cyclin D1 by a novel transcriptional mechanism not previously seen in non-transformed cells, and (b) re-established the ability of PKC agonists to activate the translational repressor 4E-BP1 and inhibit cyclin D1 translation. In contrast, PKCδ had modest and variable effects on cyclin D1 steady state levels and failed to restore responsiveness to PKC agonists. Notably, PKCα expression blocked anchorage-independent growth in colon cancer cells via a mechanism partially dependent on cyclin D1 deficiency, while PKCδ had only minor effects. Loss of PKCα and effects of its re-expression were independent of the status of the APC/β-catenin signaling pathway or known genetic alterations, indicating that they are a general characteristic of colon tumors. Thus, PKCα is a potent negative regulator of cyclin D1 expression and anchorage-independent cell growth in colon tumor cells, findings that offer important perspectives on the

  8. Cyclin D1 Is Transcriptionally Down-Regulated by ZO-2 via an E Box and the Transcription Factor c-Myc

    PubMed Central

    Huerta, Miriam; Muñoz, Rodrigo; Tapia, Rocío; Soto-Reyes, Ernesto; Ramírez, Leticia; Recillas-Targa, Félix; González-Mariscal, Lorenza

    2007-01-01

    Recent reports have indicated the participation of tight junction (TJ) proteins in the regulation of gene expression and cell proliferation. Here, we have studied the role of zona occludens (ZO)-2, a TJ peripheral protein, in the regulation of cyclin D1 transcription. We found that ZO-2 down-regulates cyclin D1 transcription in a dose-dependent manner. To understand how ZO-2 represses cyclin D1 promoter activity, we used deletion analyses and found that ZO-2 negatively regulates cyclin D1 transcription via an E box and that it diminishes cell proliferation. Because ZO-2 does not associate directly with DNA, electrophoretic mobility shift assay and chromatin immunoprecipitation (ChIP) assay were used to identify the transcription factors mediating the ZO-2–repressive effect. c-Myc was found to bind the E box present in the cyclin D1 promoter, and the overexpression of c-Myc augmented the inhibition generated by ZO-2 transfection. The presence of ZO-2 and c-Myc in the same complex was further demonstrated by immunoprecipitation. ChIP and reporter gene assays using histone deacetylases (HDACs) inhibitors demonstrated that HDACs are necessary for ZO-2 repression and that HDAC1 is recruited to the E box. We conclude that ZO-2 down-regulates cyclin D1 transcription by interacting with the c-Myc/E box element and by recruiting HDAC1. PMID:17881732

  9. Cyclin D1 is transcriptionally down-regulated by ZO-2 via an E box and the transcription factor c-Myc.

    PubMed

    Huerta, Miriam; Muñoz, Rodrigo; Tapia, Rocío; Soto-Reyes, Ernesto; Ramírez, Leticia; Recillas-Targa, Félix; González-Mariscal, Lorenza; López-Bayghen, Esther

    2007-12-01

    Recent reports have indicated the participation of tight junction (TJ) proteins in the regulation of gene expression and cell proliferation. Here, we have studied the role of zona occludens (ZO)-2, a TJ peripheral protein, in the regulation of cyclin D1 transcription. We found that ZO-2 down-regulates cyclin D1 transcription in a dose-dependent manner. To understand how ZO-2 represses cyclin D1 promoter activity, we used deletion analyses and found that ZO-2 negatively regulates cyclin D1 transcription via an E box and that it diminishes cell proliferation. Because ZO-2 does not associate directly with DNA, electrophoretic mobility shift assay and chromatin immunoprecipitation (ChIP) assay were used to identify the transcription factors mediating the ZO-2-repressive effect. c-Myc was found to bind the E box present in the cyclin D1 promoter, and the overexpression of c-Myc augmented the inhibition generated by ZO-2 transfection. The presence of ZO-2 and c-Myc in the same complex was further demonstrated by immunoprecipitation. ChIP and reporter gene assays using histone deacetylases (HDACs) inhibitors demonstrated that HDACs are necessary for ZO-2 repression and that HDAC1 is recruited to the E box. We conclude that ZO-2 down-regulates cyclin D1 transcription by interacting with the c-Myc/E box element and by recruiting HDAC1.

  10. Rescue of cyclin D1 deficiency by knockin cyclin E.

    PubMed

    Geng, Y; Whoriskey, W; Park, M Y; Bronson, R T; Medema, R H; Li, T; Weinberg, R A; Sicinski, P

    1999-06-11

    D-type cyclins and cyclin E represent two very distinct classes of mammalian G1 cyclins. We have generated a mouse strain in which the coding sequences of the cyclin D1 gene (Ccnd1) have been deleted and replaced by those of human cyclin E (CCNE). In the tissues and cells of these mice, the expression pattern of human cyclin E faithfully reproduces that normally associated with mouse cyclin D1. The replacement of cyclin D1 with cyclin E rescues all phenotypic manifestations of cyclin D1 deficiency and restores normal development in cyclin D1-dependent tissues. Thus, cyclin E can functionally replace cyclin D1. Our analyses suggest that cyclin E is the major downstream target of cyclin D1.

  11. 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.

  12. 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.

  13. Distinct Nongenomic Signal Transduction Pathways Controlled by 17β-Estradiol Regulate DNA Synthesis and Cyclin D1 Gene Transcription in HepG2 Cells

    PubMed Central

    Marino, Maria; Acconcia, Filippo; Bresciani, Francesco; Weisz, Alessandro; Trentalance, Anna

    2002-01-01

    Estrogens induce cell proliferation in target tissues by stimulating progression through the G1 phase of the cell cycle. Activation of cyclin D1 gene expression is a critical feature of this hormonal action. The existence of rapid/nongenomic estradiol-regulated protein kinase C (PKC-α) and extracellular signal-regulated kinase (ERK) signal transduction pathways, their cross talk, and role played in DNA synthesis and cyclin D1 gene transcription have been studied herein in human hepatoma HepG2 cells. 17β-Estradiol was found to rapidly activate PKC-α translocation and ERK-2/mitogen-activated protein kinase phosphorylation in this cell line. These actions were independent of each other, preceding the increase of thymidine incorporation into DNA and cyclin D1 expression, and did not involve DNA binding by estrogen receptor. The results obtained with specific inhibitors indicated that PKC-α pathway is necessary to mediate the estradiol-induced G1-S progression of HepG2 cells, but it does not exert any effect(s) on cyclin D1 gene expression. On the contrary, ERK-2 cascade was strongly involved in both G1-S progression and cyclin D1 gene transcription. Deletion of its activating protein-1 responsive element motif resulted in attenuation of cyclin D1 promoter responsiveness to estrogen. These results indicate that estrogen-induced cyclin D1 transcription can occur in HepG2 cells independently of the transcriptional activity of estrogen receptor, sustaining the pivotal role played by nongenomic pathways of estrogen action in hormone-induced proliferation. PMID:12388769

  14. Transcriptional regulation of the cyclin D1 promoter by STAT5: its involvement in cytokine-dependent growth of hematopoietic cells.

    PubMed Central

    Matsumura, I; Kitamura, T; Wakao, H; Tanaka, H; Hashimoto, K; Albanese, C; Downward, J; Pestell, R G; Kanakura, Y

    1999-01-01

    STAT5 is a member of a family of transcription factors that participate in the signal transduction pathways of many hormones and cytokines. Although STAT5 is suggested to play a crucial role in the biological effects of cytokines, its downstream target(s) associated with cell growth control is largely unknown. In a human interleukin-3 (IL-3)-dependent cell line F-36P-mpl, the induced expression of dominant-negative (dn)-STAT5 and of dn-ras led to inhibition of IL-3-dependent cell growth, accompanying the reduced expression of cyclin D1 mRNA. Also, both constitutively active forms of STAT5A (1*6-STAT5A) and ras (H-rasG12V) enabled F-36P-mpl cells to proliferate without added growth factors. In NIH 3T3 cells, 1*6-STAT5A and H-rasG12V individually and cooperatively transactivated the cyclin D1 promoter in luciferase assays. Both dn-STAT5 and dn-ras suppressed IL-3-induced cyclin D1 promoter activities in F-36P-mpl cells. Using a series of mutant cyclin D1 promoters, 1*6-STAT5A was found to transactivate the cyclin D1 promoter through the potential STAT-binding sequence at -481 bp. In electrophoretic mobility shift assays, STAT5 bound to the element in response to IL-3. Furthermore, the inhibitory effect of dn-STAT5 on IL-3-dependent growth was restored by expression of cyclin D1. Thus STAT5, in addition to ras signaling, appears to mediate transcriptional regulation of cyclin D1, thereby contributing to cytokine-dependent growth of hematopoietic cells. PMID:10064602

  15. Cyclin D1 expression in prostate carcinoma.

    PubMed

    Pereira, R A; Ravinal, R C; Costa, R S; Lima, M S; Tucci, S; Muglia, V F; Reis, R B dos; Silva, G E B

    2014-06-01

    The purpose of this study was to investigate the relationship between cyclin D1 expression and clinicopathological parameters in patients with prostate carcinoma. We assessed cyclin D1 expression by conventional immunohistochemistry in 85 patients who underwent radical prostatectomy for prostate carcinoma and 10 normal prostate tissue samples retrieved from autopsies. We measured nuclear immunostaining in the entire tumor area and based the results on the percentage of positive tumor cells. The preoperative prostate-specific antigen (PSA) level was 8.68±5.16 ng/mL (mean±SD). Cyclin D1 staining was positive (cyclin D1 expression in >5% of tumor cells) in 64 cases (75.4%) and negative (cyclin D1 expression in ≤5% of tumor cells) in 21 cases (including 15 cases with no immunostaining). Normal prostate tissues were negative for cyclin D1. Among patients with a high-grade Gleason score (≥7), 86% of patients demonstrated cyclin D1 immunostaining of >5% (P<0.05). In the crude analysis of cyclin D1 expression, the high-grade Gleason score group showed a mean expression of 39.6%, compared to 26.9% in the low-grade Gleason score group (P<0.05). Perineural invasion tended to be associated with cyclin D1 expression (P=0.07), whereas cyclin D1 expression was not associated with PSA levels or other parameters. Our results suggest that high cyclin D1 expression could be a potential marker for tumor aggressiveness.

  16. Aberrant expression of cyclin D1 in cancer

    PubMed Central

    Inoue, Kazushi; Fry, Elizabeth A.

    2016-01-01

    Cyclin D1 binds and activates cyclin-dependent kinases 4/6 (Cdk4/6) to phosphorylate the retinoblastoma (RB) family proteins, relieving E2F/DPs from the negative restraint of RB proteins and histone deacetylases. The cyclin D-Cdk4/6 complexes activate cyclin E/Cdk2 through titration of the Cdk inhibitors p21Cip1/p27Kip1. Cyclin E/Cdk2 further phosphorylates RBs, thereby activating E2F/DPs, and cells enter the S phase of the cell cycle. Cyclin D-Cdk4/6 also phosphorylates MEP50 subunit of the protein arginine methyltransferase 5 (PRMT5), which cooperates with cyclin D1 to drive lymphomagenesis in vivo. Activated PRMPT5 causes arginine methylation of p53 to suppress expression of pro-apoptotic and anti-proliferative target genes, explaining the molecular mechanism for tumorigenesis. Cyclin D1 physically interacts with transcription factors such as estrogen receptor, androgen receptor, and Myb family proteins to regulate gene expression in Cdk-independent fashion. Dmp1 is a Myb-like protein that quenches the oncogenic signals from activated Ras or HER2 by inducing Arf/p53-dependent cell cycle arrest. Cyclin D1 binds to Dmp1α to activate both Arf and Ink4a promoters to induce cell cycle arrest or apoptosis in non-transformed cells to prevent them from neoplastic transformation. Dmp1-deficiency significantly accelerates mouse mammary tumorigenesis with reduced apoptosis and increased metastasis. Cyclin D1 interferes with ligand activation of PPARγ involved in cellular differentiation; it also physically interacts with histone deacetylases (HDACs) and p300 to repress gene expression. It has also been shown that cyclin D1 accelerates tumorigenesis through transcriptional activation of miR-17/20 and Dicer1 which, in turn, represses cyclin D1 expression. Identification of cyclin D1-binding proteins/promoters will be essential for further clarification of its biological activities. PMID:28090171

  17. Consequence of the tumor-associated conversion to cyclin D1b

    PubMed Central

    Augello, Michael A; Berman-Booty, Lisa D; Carr, Richard; Yoshida, Akihiro; Dean, Jeffry L; Schiewer, Matthew J; Feng, Felix Y; Tomlins, Scott A; Gao, Erhe; Koch, Walter J; Benovic, Jeffrey L; Diehl, John Alan; Knudsen, Karen E

    2015-01-01

    Clinical evidence suggests that cyclin D1b, a variant of cyclin D1, is associated with tumor progression and poor outcome. However, the underlying molecular basis was unknown. Here, novel models were created to generate a genetic switch from cyclin D1 to cyclin D1b. Extensive analyses uncovered overlapping but non-redundant functions of cyclin D1b compared to cyclin D1 on developmental phenotypes, and illustrated the importance of the transcriptional regulatory functions of cyclin D1b in vivo. Data obtained identify cyclin D1b as an oncogene, wherein cyclin D1b expression under the endogenous promoter induced cellular transformation and further cooperated with known oncogenes to promote tumor growth in vivo. Further molecular interrogation uncovered unexpected links between cyclin D1b and the DNA damage/PARP1 regulatory networks, which could be exploited to suppress cyclin D1b-driven tumors. Collectively, these data are the first to define the consequence of cyclin D1b expression on normal cellular function, present evidence for cyclin D1b as an oncogene, and provide pre-clinical evidence of effective methods to thwart growth of cells dependent upon this oncogenic variant. PMID:25787974

  18. Post-transcriptional regulation of cyclins D1, D3 and G1 and proliferation of human cancer cells depend on IMP-3 nuclear localization.

    PubMed

    Rivera Vargas, T; Boudoukha, S; Simon, A; Souidi, M; Cuvellier, S; Pinna, G; Polesskaya, A

    2014-05-29

    RNA-binding proteins of the IMP family (insulin-like growth factor 2 (IGF2) mRNA-binding proteins 1-3) are important post-transcriptional regulators of gene expression. Multiple studies have linked high expression of IMP proteins, and especially of IMP-3, to an unfavorable prognosis in numerous types of cancer. The specific importance of IMP-3 for cancer transformation remains poorly understood. We here show that all three IMPs can directly bind the mRNAs of cyclins D1, D3 and G1 (CCND1, D3 and G1) in vivo and in vitro, and yet only IMP-3 regulates the expression of these cyclins in a significant manner in six human cancer cell lines of different origins. In the absence of IMP-3, the levels of CCND1, D3 and G1 proteins fall dramatically, and the cells accumulate in the G1 phase of the cell cycle, leading to almost complete proliferation arrest. Our results show that, compared with IMP-1 and IMP-2, IMP-3 is enriched in the nucleus, where it binds the transcripts of CCND1, D3 and G1. The nuclear localization of IMP-3 depends on its protein partner HNRNPM and is indispensable for the post-transcriptional regulation of expression of the cyclins. Cytoplasmic retention of IMP-3 and HNRNPM in human cancer cells leads to significant drop in proliferation. In conclusion, a nuclear IMP-3-HNRNPM complex is important for the efficient synthesis of CCND1, D3 and G1 and for the proliferation of human cancer cells.

  19. Cyclin D1 represses peroxisome proliferator-activated receptor alpha and inhibits fatty acid oxidation

    PubMed Central

    Hanse, Eric A.; Mashek, Douglas G.; Mashek, Mara T.; Hendrickson, Anna M.; Mullany, Lisa K.; Albrecht, Jeffrey H.

    2016-01-01

    Cyclin D1 is a cell cycle protein that promotes proliferation by mediating progression through key checkpoints in G1 phase. It is also a proto-oncogene that is commonly overexpressed in human cancers. In addition to its canonical role in controlling cell cycle progression, cyclin D1 affects other aspects of cell physiology, in part through transcriptional regulation. In this study, we find that cyclin D1 inhibits the activity of a key metabolic transcription factor, peroxisome proliferator-activated receptor α (PPARα), a member of nuclear receptor family that induces fatty acid oxidation and may play an anti-neoplastic role. In primary hepatocytes, cyclin D1 inhibits PPARα transcriptional activity and target gene expression in a cdk4-independent manner. In liver and breast cancer cells, knockdown of cyclin D1 leads to increased PPARα transcriptional activity, expression of PPARα target genes, and fatty acid oxidation. Similarly, cyclin D1 depletion enhances binding of PPARα to target sequences by chromatin immunoprecipitation. In proliferating hepatocytes and regenerating liver in vivo, induction of endogenous cyclin D1 is associated with diminished PPARα activity. Cyclin D1 expression is both necessary and sufficient for growth factor-mediated repression of fatty acid oxidation in proliferating hepatocytes. These studies indicate that in addition to playing a pivotal role in cell cycle progression, cyclin D1 represses PPARα activity and inhibits fatty acid oxidation. Our findings establish a new link between cyclin D1 and metabolism in both tumor cells and physiologic hepatocyte proliferation. PMID:27351284

  20. Cyclin D1 represses peroxisome proliferator-activated receptor alpha and inhibits fatty acid oxidation.

    PubMed

    Kamarajugadda, Sushama; Becker, Jennifer R; Hanse, Eric A; Mashek, Douglas G; Mashek, Mara T; Hendrickson, Anna M; Mullany, Lisa K; Albrecht, Jeffrey H

    2016-07-26

    Cyclin D1 is a cell cycle protein that promotes proliferation by mediating progression through key checkpoints in G1 phase. It is also a proto-oncogene that is commonly overexpressed in human cancers. In addition to its canonical role in controlling cell cycle progression, cyclin D1 affects other aspects of cell physiology, in part through transcriptional regulation. In this study, we find that cyclin D1 inhibits the activity of a key metabolic transcription factor, peroxisome proliferator-activated receptor α (PPARα), a member of nuclear receptor family that induces fatty acid oxidation and may play an anti-neoplastic role. In primary hepatocytes, cyclin D1 inhibits PPARα transcriptional activity and target gene expression in a cdk4-independent manner. In liver and breast cancer cells, knockdown of cyclin D1 leads to increased PPARα transcriptional activity, expression of PPARα target genes, and fatty acid oxidation. Similarly, cyclin D1 depletion enhances binding of PPARα to target sequences by chromatin immunoprecipitation. In proliferating hepatocytes and regenerating liver in vivo, induction of endogenous cyclin D1 is associated with diminished PPARα activity. Cyclin D1 expression is both necessary and sufficient for growth factor-mediated repression of fatty acid oxidation in proliferating hepatocytes. These studies indicate that in addition to playing a pivotal role in cell cycle progression, cyclin D1 represses PPARα activity and inhibits fatty acid oxidation. Our findings establish a new link between cyclin D1 and metabolism in both tumor cells and physiologic hepatocyte proliferation.

  1. p14ARF post-transcriptional regulation of nuclear cyclin D1 in MCF-7 breast cancer cells: discrimination between a good and bad prognosis?

    PubMed

    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

  2. Quantifying β-catenin subcellular dynamics and cyclin D1 mRNA transcription during Wnt signaling in single living cells

    PubMed Central

    Kafri, Pinhas; Hasenson, Sarah E; Kanter, Itamar; Sheinberger, Jonathan; Kinor, Noa; Yunger, Sharon; Shav-Tal, Yaron

    2016-01-01

    Signal propagation from the cell membrane to a promoter can induce gene expression. To examine signal transmission through sub-cellular compartments and its effect on transcription levels in individual cells within a population, we used the Wnt/β-catenin signaling pathway as a model system. Wnt signaling orchestrates a response through nuclear accumulation of β-catenin in the cell population. However, quantitative live-cell measurements in individual cells showed variability in nuclear β-catenin accumulation, which could occur in two waves, followed by slow clearance. Nuclear accumulation dynamics were initially rapid, cell cycle independent and differed substantially from LiCl stimulation, presumed to mimic Wnt signaling. β-catenin levels increased simultaneously at adherens junctions and the centrosome, and a membrane-centrosome transport system was revealed. Correlating β-catenin nuclear dynamics to cyclin D1 transcriptional activation showed that the nuclear accumulation rate of change of the signaling factor, and not actual protein levels, correlated with the transcriptional output of the pathway. DOI: http://dx.doi.org/10.7554/eLife.16748.001 PMID:27879202

  3. Cyclin D1 regulates hepatic estrogen and androgen metabolism.

    PubMed

    Mullany, Lisa K; Hanse, Eric A; Romano, Andrea; Blomquist, Charles H; Mason, J Ian; Delvoux, Bert; Anttila, Chelsea; Albrecht, Jeffrey H

    2010-06-01

    Cyclin D1 is a cell cycle control protein that plays an important role in regenerating liver and many types of cancer. Previous reports have shown that cyclin D1 can directly enhance estrogen receptor activity and inhibit androgen receptor activity in a ligand-independent manner and thus may play an important role in hormone-responsive malignancies. In this study, we examine a distinct mechanism by which cyclin D1 regulates sex steroid signaling, via altered metabolism of these hormones at the tissue and cellular level. In male mouse liver, ectopic expression of cyclin D1 regulated genes involved in the synthesis and degradation of sex steroid hormones in a pattern that would predict increased estrogen and decreased androgen levels. Indeed, hepatic expression of cyclin D1 led to increased serum estradiol levels, increased estrogen-responsive gene expression, and decreased androgen-responsive gene expression. Cyclin D1 also regulated the activity of several key enzymatic reactions in the liver, including increased oxidation of testosterone to androstenedione and decreased conversion of estradiol to estrone. Similar findings were seen in the setting of physiological cyclin D1 expression in regenerating liver. Knockdown of cyclin D1 in HuH7 cells produced reciprocal changes in steroid metabolism genes compared with cyclin D1 overexpression in mouse liver. In conclusion, these studies establish a novel link between the cell cycle machinery and sex steroid metabolism and provide a distinct mechanism by which cyclin D1 may regulate hormone signaling. Furthermore, these results suggest that increased cyclin D1 expression, which occurs in liver regeneration and liver diseases, may contribute to the feminization seen in these settings.

  4. 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

  5. Suberoylanilide hydroxamic acid (SAHA) inhibits EGF-induced cell transformation via reduction of cyclin D1 mRNA stability

    SciTech Connect

    Zhang, Jingjie; Ouyang, Weiming; Li, Jingxia; Zhang, Dongyun; Yu, Yonghui; Wang, York; Li, Xuejun; Huang, Chuanshu

    2012-09-01

    Suberoylanilide hydroxamic acid (SAHA) inhibiting cancer cell growth has been associated with its downregulation of cyclin D1 protein expression at transcription level or translation level. Here, we have demonstrated that SAHA inhibited EGF-induced Cl41 cell transformation via the decrease of cyclin D1 mRNA stability and induction of G0/G1 growth arrest. We found that SAHA treatment resulted in the dramatic inhibition of EGF-induced cell transformation, cyclin D1 protein expression and induction of G0/G1 growth arrest. Further studies showed that SAHA downregulation of cyclin D1 was only observed with endogenous cyclin D1, but not with reconstitutionally expressed cyclin D1 in the same cells, excluding the possibility of SAHA regulating cyclin D1 at level of protein degradation. Moreover, SAHA inhibited EGF-induced cyclin d1 mRNA level, whereas it did not show any inhibitory effect on cyclin D1 promoter-driven luciferase reporter activity under the same experimental conditions, suggesting that SAHA may decrease cyclin D1 mRNA stability. This notion was supported by the results that treatment of cells with SAHA decreased the half-life of cyclin D1 mRNA from 6.95 h to 2.57 h. Consistent with downregulation of cyclin D1 mRNA stability, SAHA treatment also attenuated HuR expression, which has been well-characterized as a positive regulator of cyclin D1 mRNA stability. Thus, our study identifies a novel mechanism responsible for SAHA inhibiting cell transformation via decreasing cyclin D1 mRNA stability and induction of G0/G1 growth arrest in Cl41 cells. -- Highlights: ► SAHA inhibits cell transformation in Cl41 cells. ► SAHA suppresses Cyclin D1 protein expression. ► SAHA decreases cyclin D1 mRNA stability.

  6. Cyclin D1 blocks the anti-proliferative function of RUNX3 by interfering with RUNX3-p300 interaction

    SciTech Connect

    Iwatani, Kazunori; Fujimoto, Tetsuhiro; Ito, Takaaki

    2010-09-24

    Research highlights: {yields} Cyclin D1 interacts with RUNX3 and inhibits the interaction and collaboration of RUNX3 with coactivator p300. {yields} Cyclin D1 blocks the ability of RUNX3 to induce the expression of cdk inhibitor p21. {yields} Cyclin D1 releases cancer cells from the inhibition of proliferation induced by RUNX3. -- Abstract: Transcriptional function of cyclin D1, whose deregulation is frequently observed in human cancers, has been suggested to contribute to cancer formation. In the present study, we show that cyclin D1 protein inhibits RUNX3 activity by directly binding to it and interfering with its interaction with p300 interaction in lung cancer cells. Cyclin D1 inhibits p300-dependent RUNX3 acetylation and negatively regulates cyclin-dependent kinase (cdk) inhibitor p21 expression. These transcriptional effects of cyclin D1 do not require cdk4/6 kinase activation. We propose that cyclin D1 provides a transcriptional switch that allows the tumor suppressor activity of RUNX3 to be repressed in cancer cells. Since RUNX3 plays tumor suppressive roles in a wide range of cancers, a non-canonical cyclin D1 function may be critical for neoplastic transformation of the epithelial cells in which RUNX3 regulates proliferation.

  7. Expression of cyclin D1 correlates with malignancy in human ovarian tumours.

    PubMed Central

    Barbieri, F.; Cagnoli, M.; Ragni, N.; Pedullà, F.; Foglia, G.; Alama, A.

    1997-01-01

    Cyclin D1 is a cell cycle regulator of G1 progression that has been suggested to play a relevant role in the pathogenesis of several human cancer types. In the current study, the expression of cyclin D1 has been investigated in a series of 33 patients, with benign (10 patients), borderline (five patients) and malignant (18 patients) ovarian disease. Cyclin D1 protein and mRNA content were analysed by Western blotting and reverse transcriptase polymerase chain reaction respectively. The levels of cyclin D1 protein were undetectable in patients with benign disease, detectable in the majority of patients with borderline disease and elevated in those with ovarian carcinomas, being significantly related to the degree of malignancy (carcinoma vs benign, P = 0.0001; benign vs borderline, P = 0.0238). A significant relationship between cyclin D1 expression and tumour proliferative activity was also found (P = 0.000001). Moreover, eight benign lesions, two borderline tumours and 11 carcinomas proved to be suitable for the analysis of cyclin D1 transcript, and emerging data demonstrated significant agreement between protein abundance and mRNA expression. Results from the current study suggest that cyclin D1 expression is associated with the degree of transformation and most probably plays a role in the early development of ovarian malignancy. Images Figure 3 Figure 4 Figure 5 Figure 6 PMID:9155044

  8. Cyclin D1 inhibits hepatic lipogenesis via repression of carbohydrate response element binding protein and hepatocyte nuclear factor 4α.

    PubMed

    Hanse, Eric A; Mashek, Douglas G; Becker, Jennifer R; Solmonson, Ashley D; Mullany, Lisa K; Mashek, Mara T; Towle, Howard C; Chau, Anhtung T; Albrecht, Jeffrey H

    2012-07-15

    Following acute hepatic injury, the metabolic capacity of the liver is altered during the process of compensatory hepatocyte proliferation by undefined mechanisms. In this study, we examined the regulation of de novo lipogenesis by cyclin D1, a key mediator of hepatocyte cell cycle progression. In primary hepatocytes, cyclin D1 significantly impaired lipogenesis in response to glucose stimulation. Cyclin D1 inhibited the glucose-mediated induction of key lipogenic genes, and similar effects were seen using a mutant (D1-KE) that does not activate cdk4 or induce cell cycle progression. Cyclin D1 (but not D1-KE) inhibited the activity of the carbohydrate response element-binding protein (ChREBP) by regulating the glucose-sensing motif of this transcription factor. Because changes in ChREBP activity could not fully explain the effect of cyclin D1, we examined hepatocyte nuclear factor 4α (HNF4α), which regulates numerous differentiated functions in the liver including lipid metabolism. We found that both cyclins D1 and D1-KE bound to HNF4α and significantly inhibited its recruitment to the promoter region of lipogenic genes in hepatocytes. Conversely, knockdown of cyclin D1 in the AML12 hepatocyte cell line promoted HNF4α activity and lipogenesis. In mouse liver, HNF4α bound to a central domain of cyclin D1 involved in transcriptional repression. Cyclin D1 inhibited lipogenic gene expression in the liver following carbohydrate feeding. Similar findings were observed in the setting of physiologic cyclin D1 expression in the regenerating liver. In conclusion, these studies demonstrate that cyclin D1 represses ChREBP and HNF4α function in hepatocytes via Cdk4-dependent and -independent mechanisms. These findings provide a direct link between the cell cycle machinery and the transcriptional control of metabolic function of the liver.

  9. The prognostic significance and value of cyclin D1, CDK4 and p16 in human breast cancer.

    PubMed

    Peurala, Emmi; Koivunen, Peppi; Haapasaari, Kirsi-Maria; Bloigu, Risto; Jukkola-Vuorinen, Arja

    2013-01-21

    Loss of the retinoblastoma protein tumor suppressor gene (RB) coding for a nuclear phosphoprotein that regulates the cell cycle is found in many human cancers and probably leads to disruption of the p16-cyclin D1-CDK4/6-RB pathway. Cyclin D1 is known to activate CDK4, which then phosphorylates the RB protein, leading to cell cycle progression. p16 inhibits CDK4, keeping RB hypophosphorylated and preventing cell cycle progression. The significance of these three markers, cyclin D1, CDK4 and p16, for breast cancer and carcinogenesis is nevertheless still controversial. The material consisted of 102 formalin-fixed human breast cancer samples, in which cyclin D1, CDK4 and p16 expression was evaluated immunohistochemically. The amounts of cyclin D1 mRNA present were analyzed by quantitative real time PCR. High cyclin D1 expression statistically significantly correlated with lower tumor grade, estrogen and progesterone receptor positivity and lower proliferation activity in breast tumors and increased breast cancer-specific survival and overall survival. Tumors with high cyclin D1 protein had 1.8 times higher expression of cyclin D1 mRNA. CDK4 expression did not correlate with cyclin D1 expression or the survival data. p16 expression was associated with Human Epidermal Growth Factor Receptor 2 (HER2) negativity and increased breast cancer-specific survival and disease-free survival. No statistical correlations between cyclin D1, CDK4 and p16 were found. Cyclin D1 was associated with a good breast cancer prognosis but functioned independently of CDK4. High cyclin D1 expression may be partially due to increased CCND1 transcription. p16 correlated with a better prognosis and may function without CDK4. In conclusion, it appears that cyclin D1, CDK4 and p16 function independently in human breast cancer.

  10. Cyclin D1 unbalances the redox status controlling cell adhesion, migration, and drug resistance in myeloma cells

    PubMed Central

    Bustany, Sophie; Bourgeais, Jérôme; Tchakarska, Guergana; Body, Simon; Hérault, Olivier; Gouilleux, Fabrice; Sola, Brigitte

    2016-01-01

    The interactions of multiple myeloma (MM) cells with their microenvironment are crucial for pathogenesis. MM cells could interact differentially with their microenvironment depending on the type of cyclin D they express. We established several clones that constitutively express cyclin D1 from the parental RPMI8226 MM cell line and analyzed the impact of cyclin D1 expression on cell behavior. We performed a gene expression profiling study on cyclin D1-expressing vs. control cells and validated the results by semi-quantitative RT-PCR. The expression of cyclin D1 altered the transcription of genes that control adhesion and migration. We confirmed that cyclin D1 increases cell adhesion to stromal cells and fibronectin, stabilizes F-actin fibers, and enhances chemotaxis and inflammatory chemokine secretion. Both control and cyclin D1-expressing cells were more resistant to acute carfilzomib treatment when cultured on stromal cells than in suspension. However, this resistance was specifically reduced in cyclin D1-expressing cells after pomalidomide pre-treatment that modifies tumor cell/microenvironment interactions. Transcriptomic analysis revealed that cyclin D1 expression was also associated with changes in the expression of genes controlling metabolism. We also found that cyclin D1 expression disrupted the redox balance by producing reactive oxygen species. The resulting oxidative stress activated the p44/42 mitogen-activated protein kinase (or ERK1/2) signaling pathway, increased cell adhesion to fibronectin or stromal cells, and controlled drug sensitivity. Our results have uncovered a new function for cyclin D1 in the control of redox metabolism and interactions of cyclin D1-expressing MM cells with their bone marrow microenvironment. PMID:27286258

  11. The tumor suppressor, parafibromin, mediates histone H3 K9 methylation for cyclin D1 repression.

    PubMed

    Yang, Yong-Jin; Han, Jeung-Whan; Youn, Hong-Duk; Cho, Eun-Jung

    2010-01-01

    Parafibromin, a component of the RNA polymerase II-associated PAF1 complex, is a tumor suppressor linked to hyperparathyroidism-jaw tumor syndrome and sporadic parathyroid carcinoma. Parafibromin induces cell cycle arrest by repressing cyclin D1 via an unknown mechanism. Here, we show that parafibromin interacts with the histone methyltransferase, SUV39H1, and functions as a transcriptional repressor. The central region (128-227 amino acids) of parafibromin is important for both the interaction with SUV39H1 and transcriptional repression. Parafibromin associated with the promoter and coding regions of cyclin D1 and was required for the recruitment of SUV39H1 and the induction of H3 K9 methylation but not H3 K4 methylation. RNA interference analysis showed that SUV39H1 was critical for cyclin D1 repression. These data suggest that parafibromin plays an unexpected role as a repressor in addition to its widely known activity associated with transcriptional activation. Parafibromin as a part of the PAF1 complex might downregulate cyclin D1 expression by integrating repressive H3 K9 methylation during transcription.

  12. Impaired nuclear export of tumor-derived c-terminal truncated cyclin D1 mutant in ESCC cancer.

    PubMed

    Hao, Meili; Chen, Xiangmei; Zhang, Ting; Shen, Tao; Xie, Qing; Xing, Xiujuan; Gu, Hongxi; Lu, Fengmin

    2011-11-01

    Cyclin D1 is a significant regulator of the G1- to S-phase transition and is often aberrant in human tumors of various origins. Although cancer-derived cyclin D1 mutants are potent oncogenes in vitro and in vivo, the mechanisms by which they contribute to neoplasia remaind to be elucidated. We previously identified a cyclin D1 mutation (Δ266-295) in esophageal cancer with deleted codons from 266 to 295 of wild-type cyclin D1, the critical COOH-terminal regulatory sequences necessary for cyclin D1 nuclear export. In the present study, this cancer-derived cyclin D1-Δ266-295 was shown to be a constitutively nuclear cyclin D1 protein with a significantly increased oncogenic potential. Moreover, the cancer-derived cyclin D1-Δ266-295 mutant was found to retain its ability to bind to and activate CDK4, which in turn phosphorylates and inactivates the pRb protein and promotes cell cycle progression. In comparison to wild-type cyclin D1a, D1-Δ266-295 exhibited enforced nuclear accumulation. In addition, the transient transfection and ectopic expression of this nuclear localized D1-Δ266-295 up-regulated endogenous Notch1 expression, indicating that the mutant retained its ability as a transcriptional regulator. Furthermore, data from the flow cytometry assay showed that D1-Δ266-295 fractionally increased >4N cell accumulation, and further analysis suggested the retriggering of DNA replication relevant to its inhibition of Cdt1 proteolysis. Therefore, the inappropriate nuclear localization of this cyclin D1 mutant may interfere with DNA replication in cultured cells, thereby contributing to genomic instability.

  13. Ubiquitination of free cyclin D1 is independent of phosphorylation on threonine 286.

    PubMed

    Germain, D; Russell, A; Thompson, A; Hendley, J

    2000-04-21

    Cyclin D1 binds and regulates the activity of cyclin-dependent kinases (CDKs) 4 and 6. Phosphorylation of the retinoblastoma protein by cyclin D1.CDK4/6 complexes during the G(1) phase of the cell cycle promotes entry into S phase. Cyclin D1 protein is ubiquitinated and degraded by the 26 S proteasome. Previous studies have demonstrated that cyclin D1 ubiquitination is dependent on its phosphorylation by glycogen synthase kinase 3beta (GSK-3beta) on threonine 286 and that this phosphorylation event is greatly enhanced by binding to CDK4 (Diehl, J. A., Cheng, M. G., Roussel, M. F., and Sherr, C. J. (1998) Genes Dev. 12, 3499-3511). We now report an additional pathway for the ubiquitination of free cyclin D1 (unbound to CDKs). We show that, when unbound to CDK4, a cyclin D1-T286A mutant is ubiquitinated. Further, we show that a mutant of cyclin D1 that cannot bind to CDK4 (cyclin D1-KE) is also ubiquitinated in vivo. Our results demonstrate that free cyclin D1 is ubiquitinated independently of its phosphorylation on threonine 286 by GSK-3beta, suggesting that, as has been shown for cyclin E, distinct pathways of ubiquitination lead to the degradation of free and CDK-bound cyclin D1. The pathway responsible for ubiquitination of free cyclin D1 may be important in limiting the effects of cyclin D1 overexpression in a variety of cancers.

  14. Kaiso Represses the Cell Cycle Gene cyclin D1 via Sequence-Specific and Methyl-CpG-Dependent Mechanisms

    PubMed Central

    Anstey, Michelle I.; Robinson, Shaiya C.; Weerawardane, Sonali M.; Daniel, Juliet M.

    2012-01-01

    Kaiso is the first member of the POZ family of zinc finger transcription factors reported to bind DNA with dual-specificity in both a sequence- and methyl-CpG-specific manner. Here, we report that Kaiso associates with and regulates the cyclin D1 promoter via the consensus Kaiso binding site (KBS), and also via methylated CpG-dinucleotides. The methyl-CpG sites appear critical for Kaiso binding to the cyclin D1 promoter, while a core KBS in close proximity to the methyl-CpGs appears to stabilize Kaiso DNA binding. Kaiso’s binding to both sites was demonstrated in vitro using electrophoretic mobility shift assays (EMSA) and in vivo using Chromatin immunoprecipitation (ChIP). To elucidate the functional relevance of Kaiso’s binding to the cyclin D1 promoter, we assessed Kaiso overexpression effects on a minimal cyclin D1 promoter-reporter that contains both KBS and CpG sites. Kaiso repressed this minimal cyclin D1 promoter-reporter in a dose-dependent manner and transcriptional repression occurred in a KBS-specific and methyl-CpG-dependent manner. Collectively our data validates cyclin D1 as a Kaiso target gene and demonstrates a mechanism for Kaiso binding and regulation of the cyclin D1 promoter. Our data also provides a mechanistic basis for how Kaiso may regulate other target genes whose promoters possess both KBS and methyl-CpG sites. PMID:23226276

  15. A jumonji (Jarid2) protein complex represses cyclin D1 expression by methylation of histone H3-K9.

    PubMed

    Shirato, Haruki; Ogawa, Satoko; Nakajima, Kuniko; Inagawa, Masayo; Kojima, Mizuyo; Tachibana, Makoto; Shinkai, Yoichi; Takeuchi, Takashi

    2009-01-09

    Covalent modifications of histone tails have critical roles in regulating gene expression. Previously, we identified the jumonji (jmj, Jarid2) gene, the jmjC domain, and a Jmj family. Recently, many Jmj family proteins have been shown to be histone demethylases, and jmjC is the catalytic domain. However, Jmj does not have histone demethylase activity because the jmjC domain lacks conserved residues for binding to cofactors. Independently of these studies, we previously showed that Jmj binds to the cyclin D1 promoter and represses the transcription of cyclin D1. Here, we show the mechanisms by which Jmj represses the transcription of cyclin D1. We found that a protein complex of Jmj had histone methyltransferase activity toward histone H3 lysine 9 (H3-K9). We also found that Jmj bound to the H3-K9 methyltransferases G9a and GLP. Expression of Jmj recruited G9a and GLP to the cyclin D1 promoter and increased H3-K9 methylation. Inactivation of both G9a and GLP, but not of only G9a, inhibited the methylation of H3-K9 in the cyclin D1 promoter and repression of cyclin D1 expression by Jmj. These results suggest that Jmj methylates H3-K9 and represses cyclin D1 expression through G9a and GLP, and that Jmj family proteins can regulate gene expression by not only histone demethylation but also other histone modification.

  16. ATM is required for rapid degradation of cyclin D1 in response to {gamma}-irradiation

    SciTech Connect

    Choo, Dong Wan; Baek, Hye Jung; Motoyama, Noboru; Cho, Kwan Ho; Kim, Hye Sun; Kim, Sang Soo

    2009-01-23

    The cellular response to DNA damage induced by {gamma}-irradiation activates cell-cycle arrest to permit DNA repair and to prevent replication. Cyclin D1 is the key molecule for transition between the G1 and S phases of the cell-cycle, and amplification or overexpression of cyclin D1 plays pivotal roles in the development of several human cancers. To study the regulation of cyclin D1 in the DNA-damaged condition, we analyzed the proteolytic regulation of cyclin D1 expression upon {gamma}-irradiation. Upon {gamma}-irradiation, a rapid reduction in cyclin D1 levels was observed prior to p53 stabilization, indicating that the stability of cyclin D1 is controlled in a p53-independent manner. Further analysis revealed that irradiation facilitated ubiquitination of cyclin D1 and that a proteasome inhibitor blocked cyclin D1 degradation under the same conditions. Interestingly, after mutation of threonine residue 286 of cyclin D1, which is reported to be the GSK-3{beta} phosphorylation site, the mutant protein showed resistance to irradiation-induced proteolysis although inhibitors of GSK-3{beta} failed to prevent cyclin D1 degradation. Rather, ATM inhibition markedly prevented cyclin D1 degradation induced by {gamma}-irradiation. Our data indicate that communication between ATM and cyclin D1 may be required for maintenance of genomic integrity achieved by rapid arrest of the cell-cycle, and that disruption of this crosstalk may increase susceptibility to cancer.

  17. Cyclin D1 repression of peroxisome proliferator-activated receptor gamma expression and transactivation.

    PubMed

    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

    2003-09-01

    The cyclin D1 gene is overexpressed in human breast cancers and is required for oncogene-induced tumorigenesis. Peroxisome proliferator-activated receptor gamma (PPAR gamma) is a nuclear receptor selectively activated by ligands of the thiazolidinedione class. PPAR gamma induces hepatic steatosis, and liganded PPAR gamma promotes adipocyte differentiation. Herein, cyclin D1 inhibited ligand-induced PPAR gamma function, transactivation, expression, and promoter activity. PPAR gamma 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 PPAR gamma ligand-binding domain linked to a heterologous DNA binding domain. Adipocyte differentiation by PPAR gamma-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 PPAR gamma ligands of PPAR gamma and PPAR gamma-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 PPAR gamma in vivo. The inhibition of PPAR gamma function by cyclin D1 is a new mechanism of signal transduction cross talk between PPAR gamma ligands and mitogenic signals that induce cyclin D1.

  18. Cyclin D1 promotes BRCA2-Rad51 interaction by restricting cyclin A/B-dependent BRCA2 phosphorylation.

    PubMed

    Chalermrujinanant, C; Michowski, W; Sittithumcharee, G; Esashi, F; Jirawatnotai, S

    2016-06-02

    BRCA2 has an important role in the maintenance of genome stability by interacting with RAD51 recombinase through its C-terminal domain. This interaction is abrogated by cyclin A-CDK2-mediated phosphorylation of BRCA2 at serine 3291 (Ser3291). Recently, we showed that cyclin D1 facilitates RAD51 recruitment to BRCA2-containing DNA repair foci, and that downregulation of cyclin D1 leads to inefficient homologous-mediated DNA repair. Here, we demonstrate that cyclin D1, via amino acids 20-90, interacts with the C-terminal domain of BRCA2, and that this interaction is increased in response to DNA damage. Interestingly, CDK4-cyclin D1 does not phosphorylate Ser3291. Instead, cyclin D1 bars cyclin A from the C-terminus of BRCA2, prevents cyclin A-CDK2-dependent Ser3291 phosphorylation and facilitates RAD51 binding to the C-terminal domain of BRCA2. These findings indicate that the interplay between cyclin D1 and other cyclins such as cyclin A regulates DNA integrity through RAD51 interaction with the BRCA2 C-terminal domain.

  19. Synergistic effects of AKAP95, Cyclin D1, Cyclin E1, and Cx43 in the development of rectal cancer

    PubMed Central

    Qi, Fengjie; Yuan, Yangyang; Zhi, Xuehong; Huang, Qian; Chen, Yuexin; Zhuang, Wenxin; Zhang, Dengcheng; Teng, Bogang; Kong, Xiangyu; Zhang, Yongxing

    2015-01-01

    Objective: To explore the expression of A-kinase anchor protein 95 (AKAP95), Cyclin D1, Cyclin E1, and Connexin43 (Cx43) in rectal cancer tissues and assess the associations between each of the proteins and pathological parameters, as well as their inter-relationships. Methods: AKAP95, Cyclin D1, Cyclin E1, and Cx43 protein expression rates were evaluated by immunohistochemistry in 50 rectal cancer specimens and 16 pericarcinoma tissues. Results: The positive rates of AKAP95, Cyclin E1, and Cyclin D1 proteins were 54.00 vs. 18.75%, 62.00 vs. 6.25%, and 72.00 vs. 31.25% in rectal cancer specimens and pericarcinoma tissues, respectively, representing statistically significant differences (P < 0.05). The positive rate of Cx43 protein expression in rectal cancer tissues was 44.00% and 62.50% in pericarcinoma tissues, and the difference between them was not significant (P > 0.05). No significant associations were found between protein expression of AKAP95, Cyclin E1, Cyclin D1, and Cx43, and the degree of differentiation, histological type, and lymph node metastasis of rectal cancer (P > 0.05). However, significant correlations were obtained between the expression rates of AKAP95 and Cyclin E1, Cyclin E1 and Cyclin D1, Cyclin E1 and Cx43 protein, and Cyclin D1 and Cx43, respectively (P < 0.05). Conclusion: AKAP95, Cyclin E1, and Cyclin D1 protein expression rates were significantly higher in rectal cancer tissues compared with pericarcinoma samples, suggesting an association between these proteins and the development and progression of rectal cancer. In addition, the significant correlations between the proteins (AKAP95 and Cyclin E1, Cyclin E1 and Cyclin D1, Cyclin E1 and Cx43 protein, and Cyclin D1 and Cx43) indicate the possible synergistic effects of these factors in the development and progression of rectal cancer. PMID:25973052

  20. Differential regulation of cyclins D1 and D3 in hepatocyte proliferation.

    PubMed

    Rickheim, David G; Nelsen, Christopher J; Fassett, John T; Timchenko, Nikolai A; Hansen, Linda K; Albrecht, Jeffrey H

    2002-07-01

    Substantial evidence suggests that cyclin D1 plays a pivotal role in the control of the hepatocyte cell cycle in response to mitogenic stimuli, whereas the closely related protein cyclin D3 has not been extensively evaluated. In the current study, we examined the regulation of cyclins D1 and D3 during hepatocyte proliferation in vivo after 70% partial hepatectomy (PH) and in culture. In contrast to cyclin D1, which was nearly undetectable in quiescent liver and substantially up-regulated after PH, cyclin D3 was constitutively expressed and induced only modestly. In the regenerating liver, the concentration of cyclin D3 was only about 10% of that of cyclin D1. Cyclin D1 formed complexes primarily with cyclin-dependent kinase 4 (cdk4), which were markedly activated in the regenerating liver and readily sequestered the cell cycle inhibitory proteins, p21 and p27. Cyclin D3 bound to both cdk4 and cdk6. Cyclin D3/cdk6 activity was readily detectable in quiescent liver and changed little after PH, and this complex appeared to play a minor role in sequestering p21 and p27. In cultured hepatocytes, epidermal growth factor or insulin had little effect, but the combination of these agents substantially induced cyclin D1 and cell cycle progression. Inhibition of Mek1 or phosphoinositide 3-kinase markedly inhibited cyclin D1 expression and replication. In contrast, cyclin D3 was expressed in the absence of mitogens and was only modestly affected by these manipulations. In addition, growth-inhibitory extracellular matrix conditions inhibited cyclin D1 but not cyclin D3 expression. In conclusion, these results support the concept that cyclin D1 is critically regulated by extracellular stimuli that control proliferation, whereas cyclin D3 is regulated through different pathways and plays a distinct role in the liver.

  1. An update on the implications of cyclin D1 in oral carcinogenesis.

    PubMed

    Ramos-García, P; Gil-Montoya, J A; Scully, C; Ayén, A; González-Ruiz, L; Navarro-Triviño, F J; González-Moles, M A

    2017-10-01

    Cyclin D1 promotes cell cycle progression during G1 phase, a key event in G1-S transition. The protein is encoded by gene CCND1, located in chromosomal band 11q13. Cyclin D1 plays key roles in cell biology, including cell proliferation and growth regulation, mitochondrial activity modulation, DNA repair, and cell migration control. CCND1 gene and its protein cyclin D1 are frequently altered by different molecular mechanisms, including amplification, chromosomal translocations, mutations, and activation of the pathways involved in cyclin D1 expression, alterations which appear to be essential in the development of human cancers, including oral carcinoma. This is the first published review of the specific features of cyclin D1 overexpression in oral oncogenesis. Starting with the physiological regulation of cyclin D1, there is an evaluation of its functions, overexpression mechanisms, and the implications of the oncogenic activation of CCND1/cyclin D1 in oral squamous cell carcinoma. The potential diagnostic and prognostic value of cyclin D1 is reviewed. The influence of CCND1/cyclin D1 on tumor size and clinical stage is reported, and an update is provided on the utilization of cyclin D1 as therapeutic target and on the combination of cyclin D1 inhibitors with cytotoxic agents. Future research lines in this field are also proposed. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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

    SciTech Connect

    Jeong, Jin Boo; Lee, Seong-Ho

    2013-01-04

    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 of 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.

  3. Regulation of Exit from Quiescence by p27 and Cyclin D1-CDK4

    PubMed Central

    Ladha, Mohamed H.; Lee, Kwang Y.; Upton, Todd M.; Reed, Michael F.; Ewen, Mark E.

    1998-01-01

    The synthesis of cyclin D1 and its assembly with cyclin-dependent kinase 4 (CDK4) to form an active complex is a rate-limiting step in progression through the G1 phase of the cell cycle. Using an activated allele of mitogen-activated protein kinase kinase 1 (MEK1), we show that this kinase plays a significant role in positively regulating the expression of cyclin D1. This was found both in quiescent serum-starved cells and in cells expressing dominant-negative Ras. Despite the observation that cyclin D1 is a target of MEK1, in cycling cells, activated MEK1, but not cyclin D1, is capable of overcoming a G1 arrest induced by Ras inactivation. Either wild-type or catalytically inactive CDK4 cooperates with cyclin D1 in reversing the G1 arrest induced by inhibition of Ras activity. In quiescent NIH 3T3 cells expressing either ectopic cyclin D1 or activated MEK1, cyclin D1 is able to efficiently associate with CDK4; however, the complex is inactive. A significant percentage of the cyclin D1-CDK4 complexes are associated with p27 in serum-starved activated MEK1 or cyclin D1 cell lines. Reduction of p27 levels by expression of antisense p27 allows for S-phase entry from quiescence in NIH 3T3 cells expressing ectopic cyclin D1, but not in parental cells. PMID:9774675

  4. SOX11 expression is highly specific for mantle cell lymphoma and identifies the cyclin D1-negative subtype

    PubMed Central

    Mozos, Ana; Royo, Cristina; Hartmann, Elena; De Jong, Daphne; Baró, Cristina; Valera, Alexandra; Fu, Kai; Weisenburger, Dennis D.; Delabie, Jan; Chuang, Shih-Sung; Jaffe, Elaine S.; Ruiz-Marcellan, Carmen; Dave, Sandeep; Rimsza, Lisa; Braziel, Rita; Gascoyne, Randy D.; Solé, Francisco; López-Guillermo, Armando; Colomer, Dolors; Staudt, Louis M.; Rosenwald, Andreas; Ott, German; Jares, Pedro; Campo, Elias

    2009-01-01

    Background Cyclin D1-negative mantle cell lymphoma is difficult to distinguish from other small B-cell lymphomas. The clinical and pathological characteristics of patients with this form of lymphoma have not been well defined. Overexpression of the transcription factor SOX11 has been observed in conventional mantle cell lymphoma. The aim of this study was to determine whether this gene is expressed in cyclin D1-negative mantle cell lymphoma and whether its detection may be useful to identify these tumors. Design and Methods The microarray database of 238 mature B-cell neoplasms was re-examined. SOX11 protein expression was investigated immunohistochemically in 12 cases of cyclin D1-negative mantle cell lymphoma, 54 cases of conventional mantle cell lymphoma, and 209 additional lymphoid neoplasms. Results SOX11 mRNA was highly expressed in conventional and cyclin D1-negative mantle cell lymphoma and in 33% of the cases of Burkitt’s lymphoma but not in any other mature lymphoid neoplasm. SOX11 nuclear protein was detected in 50 cases (93%) of conventional mantle cell lymphoma and also in the 12 cyclin D1-negative cases of mantle cell lymphoma, the six cases of lymphoblastic lymphomas, in two of eight cases of Burkitt’s lymphoma, and in two of three T-prolymphocytic leukemias but was negative in the remaining lymphoid neoplasms. Cyclin D2 and D3 mRNA levels were significantly higher in cyclin D1-negative mantle cell lymphoma than in conventional mantle cell lymphoma but the protein expression was not discriminative. The clinico-pathological features and outcomes of the patients with cyclin D1-negative mantle cell lymphoma identified by SOX11 expression were similar to those of patients with conventional mantle cell lymphoma. Conclusions SOX11 mRNA and nuclear protein expression is a highly specific marker for both cyclin D1-positive and negative mantle cell lymphoma. PMID:19880778

  5. 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

  6. Distinct proliferative and transcriptional effects of the D-type cyclins in vivo.

    PubMed

    Mullany, Lisa K; White, Peter; Hanse, Eric A; Nelsen, Christopher J; Goggin, Melissa M; Mullany, Joseph E; Anttila, Chelsea K; Greenbaum, Linda E; Kaestner, Klaus H; Albrecht, Jeffrey H

    2008-07-15

    The D-type cyclins (D1, D2 and D3) are components of the cell cycle machinery and govern progression through G(1) phase in response to extracellular signals. Although these proteins are highly homologous and conserved in evolution, they contain distinct structural motifs and are differentially regulated in various cell types. Cyclin D1 appears to play a role in many different types of cancer, whereas cyclins D2 and D3 are less frequently associated with malignancy. In this study, we transiently expressed cyclin D1, D2 or D3 in hepatocytes and analyzed transcriptional networks regulated by each. All three D-type cyclins promoted robust hepatocyte proliferation and marked liver growth, although cyclin D3 stimulated less DNA synthesis than D1 or D2. Accordingly, the three D-type cyclins similarly activated genes associated with cell division. Cyclin D1 regulated transcriptional pathways involved in the metabolism of carbohydrates, lipids, amino acids, and other substrates, whereas cyclin D2 did not regulate these pathways despite having an equivalent effect on proliferation. Comparison of transcriptional profiles following 70% partial hepatectomy and cyclin D1 transduction revealed a highly significant overlap, suggesting that cyclin D1 may regulate diverse cellular processes in the regenerating liver. In summary, these studies provide the first comparative analysis of the transcriptional networks regulated by the D-type cyclins and provide insight into novel functions of these key cell cycle proteins. Further study of the unique targets of cyclin D1 should provide further insight into its prominent role in proliferation, growth and cancer.

  7. 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.

  8. Induction of cyclin D1 by submicromolar concentrations of arsenite in human epidermal keratinocytes

    SciTech Connect

    Hwang, B.-J.; Utti, Charles; Steinberg, Mark . E-mail: marste@sci.ccny.cuny.edu

    2006-12-01

    Arsenic is a prevalent environmental carcinogen but arsenic is not directly mutagenic and the mechanism by which arsenite brings about oncogenic transformation is poorly understood. To gain insight into the oncogenic properties of arsenic, we studied the expression of cyclin D1 in cultured human epidermal keratinocytes treated with submicromolar concentrations of sodium arsenite. Arsenite at concentrations between 200 and 800 nM over a 3-day period brought about an increase in cell growth rate. Uptake of the vital stain, neutral red, arsenite at 200 and 400 nM concentrations brought about a parallel increase in cell viability over the same treatment period. Analysis of cell cycle parameters by flow cytometry showed that the growth stimulation was accompanied by a concomitant shift from the G1 into the S/G2 cell cycle compartment in the arsenite-treated cells. Real-time PCR analysis of cyclin D1 transcription showed that there was an induction of more than three-fold in cells exposed to 400 nM arsenite for 3 days. Quantitation of cyclin D levels in Western blots showed that arsenite treatment caused a time-dependent induction of cyclin D proteins representing an induction of about 2.0-fold after a 7 day treatment period. Electrophoretic mobility shift assays (EMSA) showed that arsenite also stimulated binding of the transcription factors, AP1 and CREBP to their respective binding motifs within 3 days. This supports a mechanism of oncogenesis based on persistent upregulation of D type cyclins leading to a concomitant loss of G1/S checkpoint control.

  9. The Role of Cyclin D1 in Altering Stromal-Epithelial Interactions in Prostate Carcinogenesis

    DTIC Science & Technology

    2008-03-01

    adenocarcinomas. One study of cyclin D1 expression in esophageal carcinomas indicated that cyclin D1 is strongly expressed in stromal fibroblasts. In this study...proliferate faster than controls in vivo in our tissue recombination model. Although cyclin D1 can increase BPH-1 cell motility and promote cell...Alarid ET, Turner T, Donjacour AA, Boutin EL, Foster BA. Normal and abnormal development of the male urogenital tract: role of androgens, mesenchymal

  10. Age Dependent Switching Role of Cyclin D1 in Breast Cancer

    PubMed Central

    Rinaldi, Carmela; Malara, Natalia Maria; D’Angelo, Rosalia; Sidoti, Antonina; Leotta, Attilio; Lio, Santo; Caparello, Basilio; Ruggeri, Alessia; Mollace, Vincenzo; Amato, Aldo

    2012-01-01

    Background: Cyclin D1 gene (CCND1) plays pivotal roles in the development of several human cancers, including breast cancer, functioning as an oncogene. The aim of this study was to better understand the molecular dynamics of ductal carcinomas with regard to proliferation and the ageing process. Methods: 130 cases of ductal breast cancer in postmenopausal women, aged 52–96 in 3 age classes were selected. Tumoral tissues preserved in formaldehyde solution and subsequently embedded in paraffin were subjected to analysis Fluorescence in situ Hybridization (FISH), Reverse Transcription-Polymerase Chain Reaction (RT- PCR) and immuno-histochemical tests. The molecular variables studied were estimated in relation to the patients’ age. Results: The results obtained suggest that the increment of the levels of cyclin D1 in intra-ductal breast tumors in older woman that we have examined is significantly associated with a lower proliferation rate. Conclusion: Cyclin D1, which characterizes tumor in young women as molecular director involved in strengthening tumoral proliferation mechanisms, may be seen as a potential blocking molecular switch in corresponding tumours in old women. PMID:22231956

  11. Peculiarities of cyclin D1 expression in reproductive and menopausal women with cervical hyperkeratosis.

    PubMed

    Chogovadze, N K; Dzhugeli, M K; Kachechiladze, M G; Burkadze, G M

    2013-10-01

    Morphological diagnosis of cervical intraepithelial neoplastic (CIN) lesions sometimes requires an additional study of molecular markers. Cyclin D1 is a key regulatory protein, which regulates cell cycle progression from G1 to S phase. Disruption of G1/S regulatory mechanisms is basic mechanism of HPV mediated malignant transformation of cervical epithelium. The aim of the research was to study the peculiarities of cyclin D1 protein expression in reproductive and menopausal women with cervical hyperkeratosis. We examined cyclin D1 protein expression in 381 reproductive and 233 menopausal women with cyto-colposcopically detected and histologically proved hyperkeratosis, using immunohistochemical method. Monoclonal ready to use (RTU) antibody against cyclin D1 antigen (Dako) was used. Cyclin D1 positivity in ≤50% of cells considered as low and in ≥50% - as high expression. High expression of cyclin D1 was present in CIN1 of 93,3% reproductive and 66,7% menopausal women, whilst in CINII the high expression was revealed in 53,3% and 43,8% respectively. The weak expression of cyclin D1 was present in only one cases of CINIII, other CINIII cases were all negative. The expression of cyclin D1 protein in cervical intraepithelial neoplastic lesions is not regular, however the overexpression of cyclin D1 is almost always present in CIN1 of reproductive women, in which it might be considered as an additional diagnostic marker.

  12. The regulation of cyclin D1 degradation: roles in cancer development and the potential for therapeutic invention

    PubMed Central

    Alao, John P

    2007-01-01

    Cyclin D1 is an important regulator of cell cycle progression and can function as a transcriptionl co-regulator. The overexpression of cyclin D1 has been linked to the development and progression of cancer. Deregulated cyclin D1 degradation appears to be responsible for the increased levels of cyclin D1 in several cancers. Recent findings have identified novel mechanisms involved in the regulation of cyclin D1 stability. A number of therapeutic agents have been shown to induce cyclin D1 degradation. The therapeutic ablation of cyclin D1 may be useful for the prevention and treatment of cancer. In this review, current knowledge on the regulation of cyclin D1 degradation is discussed. Novel insights into cyclin D1 degradation are also discussed in the context of ablative therapy. A number of unresolved questions regarding the regulation of cellular cyclin D1 levels are also addressed. PMID:17407548

  13. Translokin (Cep57) interacts with cyclin D1 and prevents its nuclear accumulation in quiescent fibroblasts.

    PubMed

    Ruiz-Miró, Maria; Colomina, Neus; Fernández, Rita M H; Garí, Eloi; Gallego, Carme; Aldea, Martí

    2011-05-01

    Nuclear accumulation of cyclin D1 because of altered trafficking or degradation is thought to contribute directly to neoplastic transformation and growth. Mechanisms of cyclin D1 localization in S phase have been studied in detail, but its control during exit from the cell cycle and quiescence is poorly understood. Here we report that translokin (Tlk), a microtubule-associated protein also termed Cep57, interacts with cyclin D1 and controls its nucleocytoplasmic distribution in quiescent cells. Tlk binds to regions of cyclin D1 also involved in binding to cyclin-dependent kinase 4 (Cdk4), and a fraction of cyclin D1 associates to the juxtanuclear Tlk network in the cell. Downregulation of Tlk levels results in undue nuclear accumulation of cyclin D1 and increased Cdk4-dependent phosphorylation of pRB under quiescence conditions. In turn, overexpression of Tlk prevents proper cyclin D1 accumulation in the nucleus of proliferating cells in an interaction-dependent manner, inhibits Cdk4-dependent phosphorylation of pRB and hinders cell cycle progression to S phase. We propose that the Tlk acts as a key negative regulator in the pathway that drives nuclear import of cyclin D1, thus contributing to prevent pRB inactivation and to maintain cellular quiescence.

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

    SciTech Connect

    Sumrejkanchanakij, Piyamas; Eto, Kazuhiro; Ikeda, Masa-Aki . E-mail: mikeda.emb@tmd.ac.jp

    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{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.

  15. Characterization of cytoplasmic cyclin D1 as a marker of invasiveness in cancer

    PubMed Central

    Santacana, Maria; Fernández-Hernández, Rita; Gatius, Sònia; Pedraza, Neus; Pallarés, Judit; Cemeli, Tània; Valls, Joan; Tarres, Marc; Ferrezuelo, Francisco; Dolcet, Xavier; Matias-Guiu, Xavier; Garí, Eloi

    2016-01-01

    Cyclin D1 (Ccnd1) is a proto-oncogen amplified in many different cancers and nuclear accumulation of Ccnd1 is a characteristic of tumor cells. Ccnd1 activates the transcription of a large set of genes involved in cell cycle progress and proliferation. However, Ccnd1 also targets cytoplasmic proteins involved in the regulation of cell migration and invasion. In this work, we have analyzed by immunohistochemistry the localization of Ccnd1 in endometrial, breast, prostate and colon carcinomas with different types of invasion. The number of cells displaying membranous or cytoplasmic Ccnd1 was significantly higher in peripheral cells than in inner cells in both collective and pushing invasion patterns of endometrial carcinoma, and in collective invasion pattern of colon carcinoma. Also, the cytoplasmic localization of Ccnd1 was higher when tumors infiltrated as single cells, budding or small clusters of cells. To evaluate cytoplasmic function of cyclin D1, we have built a variant (Ccnd1-CAAX) that remains attached to the cell membrane therefore sequestering this cyclin in the cytoplasm. Tumor cells harboring Ccnd1-CAAX showed high levels of invasiveness and metastatic potential compared to those containing the wild type allele of Ccnd1. However, Ccnd1-CAAX expression did not alter proliferative rates of tumor cells. We hypothesize that the role of Ccnd1 in the cytoplasm is mainly associated with the invasive capability of tumor cells. Moreover, we propose that subcellular localization of Ccnd1 is an interesting guideline to measure cancer outcome. PMID:27105504

  16. 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.

  17. Metformin induces degradation of cyclin D1 via AMPK/GSK3β axis in ovarian cancer.

    PubMed

    Gwak, HyeRan; Kim, Youngmin; An, Haein; Dhanasekaran, Danny N; Song, Yong Sang

    2017-02-01

    Metformin, which is widely used as an anti-diabetic drug, reduces cancer related morbidity and mortality. However, the role of metformin in cancer is not fully understood. Here, we first describe that the anti-cancer effect of metformin is mediated by cyclin D1 deregulation via AMPK/GSK3β axis in ovarian cancer cells. Metformin promoted cytotoxic effects only in the cancer cells irrespective of the p53 status and not in the normal primary-cultured cells. Metformin induced the G1 cell cycle arrest, in parallel with a decrease in the protein expressions of cyclin D1 without affecting its transcriptional levels. Using a proteasomal inhibitor, we could address that metformin-induced decrease in cyclin D1 through the ubiquitin/proteasome process. Cyclin D1 degradation by metformin requires the activation of GSK3β, as determined based on the treatment with GSK3β inhibitors. The activation of GSK3β correlated with the inhibitory phosphorylation by Akt as well as p70S6K through AMPK activation in response to metformin. These findings suggested that the anticancer effects of metformin was induced due to cyclin D1 degradation via AMPK/GSK3β signaling axis that involved the ubiquitin/proteasome pathway specifically in ovarian cancer cells. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  18. Berberine Suppresses Cyclin D1 Expression through Proteasomal Degradation in Human Hepatoma Cells

    PubMed Central

    Wang, Ning; Wang, Xuanbin; Tan, Hor-Yue; Li, Sha; Tsang, Chi Man; Tsao, Sai-Wah; Feng, Yibin

    2016-01-01

    The aim of this study is to explore the underlying mechanism on berberine-induced Cyclin D1 degradation in human hepatic carcinoma. We observed that berberine could suppress both in vitro and in vivo expression of Cyclin D1 in hepatoma cells. Berberine exhibits dose- and time-dependent inhibition on Cyclin D1 expression in human hepatoma cell HepG2. Berberine increases the phosphorylation of Cyclin D1 at Thr286 site and potentiates Cyclin D1 nuclear export to cytoplasm for proteasomal degradation. In addition, berberine recruits the Skp, Cullin, F-box containing complex-β-Transducin Repeat Containing Protein (SCFβ-TrCP) complex to facilitate Cyclin D1 ubiquitin-proteasome dependent proteolysis. Knockdown of β-TrCP blocks Cyclin D1 turnover induced by berberine; blocking the protein degradation induced by berberine in HepG2 cells increases tumor cell resistance to berberine. Our results shed light on berberine′s potential as an anti-tumor agent for clinical cancer therapy. PMID:27854312

  19. Berberine Suppresses Cyclin D1 Expression through Proteasomal Degradation in Human Hepatoma Cells.

    PubMed

    Wang, Ning; Wang, Xuanbin; Tan, Hor-Yue; Li, Sha; Tsang, Chi Man; Tsao, Sai-Wah; Feng, Yibin

    2016-11-15

    The aim of this study is to explore the underlying mechanism on berberine-induced Cyclin D1 degradation in human hepatic carcinoma. We observed that berberine could suppress both in vitro and in vivo expression of Cyclin D1 in hepatoma cells. Berberine exhibits dose- and time-dependent inhibition on Cyclin D1 expression in human hepatoma cell HepG2. Berberine increases the phosphorylation of Cyclin D1 at Thr286 site and potentiates Cyclin D1 nuclear export to cytoplasm for proteasomal degradation. In addition, berberine recruits the Skp, Cullin, F-box containing complex-β-Transducin Repeat Containing Protein (SCF(β-TrCP)) complex to facilitate Cyclin D1 ubiquitin-proteasome dependent proteolysis. Knockdown of β-TrCP blocks Cyclin D1 turnover induced by berberine; blocking the protein degradation induced by berberine in HepG2 cells increases tumor cell resistance to berberine. Our results shed light on berberine's potential as an anti-tumor agent for clinical cancer therapy.

  20. 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.

  1. T3 enhances thyroid cancer cell proliferation through TRβ1/Oct-1-mediated cyclin D1 activation.

    PubMed

    Perri, Anna; Catalano, Stefania; Bonofiglio, Daniela; Vizza, Donatella; Rovito, Daniela; Qi, Hongyan; Aquila, Saveria; Panza, Salvatore; Rizza, Pietro; Lanzino, Marilena; Andò, Sebastiano

    2014-01-25

    Several studies have demonstrated that thyroid hormone T3 promotes cancer cell growth, even though the molecular mechanism involved in such processes still needs to be elucidated. In this study we demonstrated that T3 induced proliferation in papillary thyroid carcinoma cell lines concomitantly with an up-regulation of cyclin D1 expression, that is a critical mitogen-regulated cell-cycle control element. Our data revealed that T3 enhanced the recruitment of the TRβ1/Oct-1 complex on Octamer-transcription factor-1 site within cyclin D1 promoter, leading to its transactivation. In addition, silencing of TRβ1 or Oct-1 expression by RNA interference reversed both increased cell proliferation and up-regulation of cyclin D1, underlying the important role of both transcriptional factors in mediating these effects. Finally, T3-induced increase in cell growth was abrogated after knocking down cyclin D1 expression. All these findings highlight a new molecular mechanism by which T3 promotes thyroid cancer cell growth.

  2. [Expression and clinical significance of Pin1 and Cyclin D1 in cervical cancer cell lines and cervical epithelial tissues].

    PubMed

    Li, Hong-Yu; Xu, Qian; Zhu, Tao; Zhou, Jin-Hua; Deng, Dong-Rui; Wang, Shi-Xuan; Lu, Yun-Ping; Ma, Ding

    2006-03-01

    Peptidyl-prolyl cis/trans isomerase Pin1 is prevalently overexpressed in human cancers. Up-regulation of Pin1 elevates the expression of Cyclin D1, and plays an important role in tumorigenesis and tumor progression. This study was to investigate the expression and clinical significance of Pin1 and Cyclin D1 in cervical cancer cell lines and cervical epithelial tissues. The expression of Pin1 and Cyclin D1 in cervical cancer cell lines HeLa, SiHa, C33a and Caski were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Their expression in 88 samples of cervical tissues, including 10 samples of normal cervix, 21 samples of cervical intraepithelial neoplasia (CIN), and 57 samples of invasive cervical cancer, were detected by immunohistochemistry. The mRNA and protein levels of Pin1 were significantly higher in HeLa, SiHa, C33a, and Caski cells than in normal cervical epithelial tissues (P<0.05). The expression of Pin1 increased progressively along with the disease process from normal cervix to CIN, and to invasive cervical cancer (0%, 47.62%, 64.91%, P<0.05). Pin1 expression had no relation to disease stage (FIGO), pathologic grade, and pelvic lymph node metastasis status (P>0.05). The positive rate of Pin1 was significantly higher in cervical adenocarcinoma than in cervical squamous cell carcinoma (100% vs. 60.0%, P<0.05). In cervical cancer tissues, the overexpression of Pin1 was positively correlated to that of Cyclin D1 (P<0.05). Pin1 is overexpressed in HeLa, SiHa, C33a and Caski cell lines as well as in cervical cancer tissues. The overexpression of Pin1 is closely related to Cyclin D1 expression in cervical cancer. The aberrant expression of Pin1 and Cyclin D1 might contribute to tumorigenesis of cervical cancer.

  3. Plasma cell myeloma with lymphoplasmacytic morphology and cyclin D1 expression, an uncommon variant

    PubMed Central

    Krause, John R.

    2017-01-01

    The genetic complexity of multiple myeloma is due in part to the accumulation of mutations, with primary and secondary events. One such secondary event is the development of a gene mutation that may result in overexpression of cyclin D1. The pathway involving cyclin D1 is intricately involved in cell cycle regulation from the G1 to S phase, and alterations may contribute to tumorigenesis. We present a case of cyclin D1–positive multiple myeloma with lymphoplasmacytic morphology and discuss potential diagnostic pitfalls and effects on prognosis. PMID:28405079

  4. Attenuation of microRNA-16 derepresses the cyclins D1, D2 and E1 to provoke cardiomyocyte hypertrophy

    PubMed Central

    Huang, Shuai; Zou, Xiao; Zhu, Jie-Ning; Fu, Yong-Heng; Lin, Qiu-Xiong; Liang, Ye-You; Deng, Chun-Yu; Kuang, Su-Juan; Zhang, Meng-Zhen; Liao, Yu-Lin; Zheng, Xi-Long; Yu, Xi-Yong; Shan, Zhi-Xin

    2015-01-01

    Cyclins/retinoblastoma protein (pRb) pathway participates in cardiomyocyte hypertrophy. MicroRNAs (miRNAs), the endogenous small non-coding RNAs, were recognized to play significant roles in cardiac hypertrophy. But, it remains unknown whether cyclin/Rb pathway is modulated by miRNAs during cardiac hypertrophy. This study investigates the potential role of microRNA-16 (miR-16) in modulating cyclin/Rb pathway during cardiomyocyte hypertrophy. An animal model of hypertrophy was established in a rat with abdominal aortic constriction (AAC), and in a mouse with transverse aortic constriction (TAC) and in a mouse with subcutaneous injection of phenylephrine (PE) respectively. In addition, a cell model of hypertrophy was also achieved based on PE-promoted neonatal rat ventricular cardiomyocyte and based on Ang-II-induced neonatal mouse ventricular cardiomyocyte respectively. We demonstrated that miR-16 expression was markedly decreased in hypertrophic myocardium and hypertrophic cardiomyocytes in rats and mice. Overexpression of miR-16 suppressed rat cardiac hypertrophy and hypertrophic phenotype of cultured cardiomyocytes, and inhibition of miR-16 induced a hypertrophic phenotype in cardiomyocytes. Expressions of cyclins D1, D2 and E1, and the phosphorylated pRb were increased in hypertrophic myocardium and hypertrophic cardiomyocytes, but could be reversed by enforced expression of miR-16. Cyclins D1, D2 and E1, not pRb, were further validated to be modulated post-transcriptionally by miR-16. In addition, the signal transducer and activator of transcription-3 and c-Myc were activated during myocardial hypertrophy, and inhibitions of them prevented miR-16 attenuation. Therefore, attenuation of miR-16 provoke cardiomyocyte hypertrophy via derepressing the cyclins D1, D2 and E1, and activating cyclin/Rb pathway, revealing that miR-16 might be a target to manage cardiac hypertrophy. PMID:25583328

  5. Cyclin D1 is an essential mediator of apoptotic neuronal cell death.

    PubMed Central

    Kranenburg, O; van der Eb, A J; Zantema, A

    1996-01-01

    Many neurons in the developing nervous system undergo programmed cell death, or apoptosis. However, the molecular mechanism underlying this phenomenon is largely unknown. In the present report, we present evidence that the cell cycle regulator cyclin D1 is involved in the regulation of neuronal cell death. During neuronal apoptosis, cyclin D1-dependent kinase activity is stimulated, due to an increase in cyclin D1 levels. Moreover, artificial elevation of cyclin D1 levels is sufficient to induce apoptosis, even in non-neural cell types. Cyclin D1-induced apoptosis, like neuronal apoptosis, can be inhibited by 21 kDa E1B, Bcl2 and pRb, but not by 55 kDa E1B. Most importantly, however, overexpression of the cyclin D-dependent kinase inhibitor p16INK4 protects neurons from apoptotic cell death, demonstrating that activation of endogenous cyclin D1-dependent kinases is essential during neuronal apoptosis. These data support a model in which neuronal apoptosis results from an aborted attempt to activate the cell cycle in terminally differentiated neurons. Images PMID:8598205

  6. Cyclin D1 G870A polymorphism and risk of colorectal cancer: a case control study.

    PubMed

    Sameer, Aga Syed; Parray, Fazl Q; Dar, Manzoor Ahmad; Nissar, Saniya; Banday, Mujeeb Zafar; Rasool, Sabha; Gulzar, G M; Chowdri, Nissar A; Siddiqi, Mushtaq A

    2013-03-01

    The present study aimed to analyse the role of cyclin D1 A870G polymorphism in modulating the susceptibility to colorectal cancer (CRC) in the Kashmiri population. The genotype distribution of the cyclin D1 gene in 130 CRC cases in comparison with 160 healthy controls was investigated. No direct significant association between cyclin D1 genotypes and CRC was observed; however, the AG and AA genotypes were found to be associated with an increased risk of CRC compared to the GG genotype, with an almost 2-fold increase in OR. This study suggests that the cyclin D1 polymorphism is associated with an increased risk of CRC in the Kashmiri population.

  7. Expression of Cyclin D1 and P16 in Esophageal Squamous Cell Carcinoma.

    PubMed

    Dey, Biswajit; Raphael, Vandana; Khonglah, Yookarin; GiriLynrah, Kyrshanlang

    2015-10-01

    BACKGROUND Esophageal squamous cell carcinoma (ESCC) is one of the lethal cancers with a high incidence rate in Asia. Many genes including cyclin D1 and p16 play important role in its carcinogenesis. We aimed to analyze the expressions of cyclin D1 and p16 with the various clinicopathological characteristics of ESCC. METHODS We examined 30 biopsy samples of ESCC for cyclin D1 and p16 protein expressions using immunohistochemistry. Immunointensity was classified as no immunostaining (-), weakly immunostaining (+), weak immunostaining (++) and strongly positive immunostaining (+++). RESULTS Out of the 30 cases, positive expression of cyclin D1 was detected in 26 cases (86.7%). The percentage of tumors with invasion to the adventitia (88.2%), lymph node metastasis (87.5%), and tumors which were poorly differentiated (92.9%) were higher in cyclin D1 positive tumors than in the cyclin D1 negative tumors. However no significant association was found between cyclin D1 expression and the different clinicopathological parameters.There were 22 cases of ESCC (73.3 %) which showed negativity for p16. The percentage of tumors with invasion to the adventitia (82.4%) and poorly differentiated tumors (92.9%) were higher in the p16 negative tumors than in the p16 positive tumors. There was significant association between the histological grade and p16 expression (p=0.012). However, there were no significant association with regard to site, size and lymph node status of the tumors and p16 expression. CONCLUSION The study shows that alterations of cyclin D1 and p16 play an important role in ESCC. Loss of p16 expression was associated with poor differentiation.

  8. Cyclin D1-negative blastoid mantle cell lymphoma identified by SOX11 expression.

    PubMed

    Zeng, Weifen; Fu, Kai; Quintanilla-Fend, Leticia; Lim, Megan; Ondrejka, Sarah; Hsi, Eric D

    2012-02-01

    SOX11 expression has been recently shown to be useful in the diagnosis of mantle cell lymphoma (MCL), including cyclin D1-negative MCL with typical morphology. We evaluated SOX11 expression pattern in B-cell non-Hodgkin lymphoma (B-NHL) subtypes to confirm specificity and used it as a feature to identify the first reported cases of cyclin D1-negative blastoid MCL. SOX11 expression was evaluated by immunohistochemistry in 140 cases of mature B-NHL, including 4 cases of suspected blastoid MCL that lacked cyclin D1 expression and 8 cases of CD5-positive diffuse large B-cell lymphoma (DLBL). In addition, 5 cases of B or T lymphoblastic lymphoma were included. Nuclear expression of SOX11 was found in cyclin D1-positive MCL (30/30, 100%) and in a case of cyclin D1-negative MCL with typical morphology. SOX11 was also expressed in Burkitt lymphoma (1/5, 20%) and lymphoblastic lymphoma (2/3 T-LBLs, 2/2 B-LBLs, overall 4/5, 80%), whereas all cases of DLBL (including CD5 DLBL) and other small B-NHL were negative. The 4 suspected cases of blastoid MCL were also SOX11. These cases had a complex karyotype that included 12p abnormalities. We confirmed prior reports that stated that SOX11 nuclear expression was a specific marker for MCL, including cyclin D1-negative MCL with typical morphology. To our knowledge, this is the first report regarding its use in identifying cases of cyclin D1-negative blastoid MCL. Routine use of SOX11 in cases of suspected CD5 DLBL might help identify additional cases of cyclin D1-negative blastoid MCL.

  9. Divergent cyclin B1 expression and Rb/p16/cyclin D1 pathway aberrations among pulmonary neuroendocrine tumors.

    PubMed

    Igarashi, Toru; Jiang, Shi-Xu; Kameya, Toru; Asamura, Hisao; Sato, Yuichi; Nagai, Kanji; Okayasu, Isao

    2004-10-01

    A total of 111 pulmonary neuroendocrine tumors comprising 13 typical carcinoids, five atypical carcinoids, 44 large-cell neuroendocrine carcinomas and 49 small-cell carcinomas were immunohistochemically studied for dysregulated cyclin B1 expression and disruption of the Rb/p16/cyclin D1 pathway (Rb pathway), and the results were correlated with tumor proliferation activity and clinical outcome. Overexpression of cyclins B1 and D1, respectively, was detected in no and 15% typical carcinoids, 20 and 20% atypical carcinoids, 84 and 32% large-cell neuroendocrine carcinomas, 84 and 10% small-cell carcinomas. Loss of Rb and p16 expression, respectively, was observed in no and 14% typical carcinoids, no and 40% atypical carcinoids, 49 and 18% large-cell neuroendocrine carcinomas, 84 and 8% small-cell carcinomas. In summary, 29% typical carcinoids, 20% atypical carcinoids, 78% large-cell neuroendocrine carcinomas and 93% small-cell carcinomas had Rb pathway aberrations. Rb pathway aberration was mostly attributed to Rb loss in small-cell carcinomas, while p16 loss and/or cyclin D1 overexpression besides Rb loss also played an important role in large-cell neuroendocrine carcinomas, while cyclin D1 overexpression was the only cause of Rb pathway aberration in carcinoid tumors. Thus, both cyclin B1-associated G2/M arrest and Rb-mediated G1 arrest are consistently compromised in high-grade large-cell neuroendocrine carcinoma and small-cell carcinoma, but are generally intact or occasionally altered in carcinoid tumor; the mechanisms involved in Rb pathway aberration among the tumor categories are different, reflecting a genetic divergence among the individual tumor categories. Cyclin B1 expression closely correlated with the Ki-67 labeling index either in the individual tumor categories or overall tumors (P < 0.0001, r = 0.742), suggesting that cyclin B1 is one of the key factors regulating cell proliferation in pulmonary neuroendocrine tumors. Neither cyclins B1 and D1, Rb, p

  10. Expression of cyclin D1 and p16 in psoriasis before and after phototherapy.

    PubMed

    Abou EL-Ela, M; Nagui, N; Mahgoub, D; El-Eishi, N; Fawzy, M; El-Tawdy, A; Abdel Hay, R; Rashed, L

    2010-10-01

    Psoriasis vulgaris (PV) is characterized by keratinocyte hyperproliferation. Altered expression of cell-cycle regulatory genes involved in the cyclin D1 ⁄ p16 INK4-pRb pathway may contribute to this epidermal hyperproliferation. To assess the expression of cyclin D1 and p16 in psoriasis, and to evaluate the effect of phototherapy on their expression. The study population comprised 25 patients with PV and 10 healthy controls. Patients were treated with 24 sessions of either narrowband ultraviolet (UV) B or psoralen UVA. Skin biopsies were taken from the affected skin of each patient before and after treatment, and from the healthy controls, to examine cyclin D1 and p16 expression. Before phototherapy, the mean value of cyclin D1 concentration in patients was significantly greater than that in controls and the mean value of p16 concentration in patients was significantly lower than that in controls. Following treatment, we detected a significant decrease in cyclin D1 and a significant increase in p16. Cyclin D1 upregulation and p16 downregulation may play a role in the pathogenesis of psoriasis. Normalization of the levels of both parameters may be a mechanism by which phototherapy induces remission in psoriasis.

  11. Glycogen synthase kinase 3β and cyclin D1 expression in cervical carcinogenesis

    PubMed Central

    Park, Hyunsoo; Lee, Myunghwa; Kim, Dae Woon; Hong, Seo Yoo

    2016-01-01

    Objective Glycogen synthase kinase 3β (GSK3β) is a pluripotent protein kinase involved in the development of cancers through regulation of numerous oncogenic molecules. Cyclin D1, an important regulator of G1 to S phase transition in various cells, is one of target proteins that GSK3β regulate. Our objective was to assess the expression of GSK3β and cyclin D1 in cervical neoplasm of different histologic grades and to identify their correlation in cervical carcinogenesis. Methods Immunohistochemical analysis of GSK3β and cyclin D1 was performed in a total of 137 patients with 12 normal, 62 cervical intraepithelial neoplasia (CIN) (31 CIN1 and 31 CIN3) and 63 invasive cancers including 56 squamous cell carcinomas and 7 adenocarcinomas. Results The expression of GSK3β increased in parallel with the lesion grade, while that of cyclin D1 decreased with severity of the lesion (P<0.001). There was a significant inverse correlation between GSK3β and cyclin D1 expression in overall cervical neoplasia (Φ=-0.413, P<0.001). GSK3β expression was higher in squamous cell carcinoma than in adenocarcinoma (P=0.049). Conclusion These results suggest that the expressional increase in GSK3β plays a role in cervical carcinogenesis and has inverse correlation with cyclin D1 expression in this process. In addition, GSK3β expression appears to be associated with the histologic type of cervical cancer, especially squamous cell carcinoma. PMID:27896249

  12. Tight function zonula occludens-3 regulates cyclin D1-dependent cell proliferation.

    PubMed

    Capaldo, Christopher T; Koch, Stefan; Kwon, Michael; Laur, Oskar; Parkos, Charles A; Nusrat, Asma

    2011-05-15

    Coordinated regulation of cell proliferation is vital for epithelial tissue homeostasis, and uncontrolled proliferation is a hallmark of carcinogenesis. A growing body of evidence indicates that epithelial tight junctions (TJs) play a role in these processes, although the mechanisms involved are poorly understood. In this study, we identify and characterize a novel plasma membrane pool of cyclin D1 with cell-cycle regulatory functions. We have determined that the zonula occludens (ZO) family of TJ plaque proteins sequesters cyclin D1 at TJs during mitosis, through an evolutionarily conserved class II PSD-95, Dlg, and ZO-1 (PDZ)-binding motif within cyclin D1. Disruption of the cyclin D1/ZO complex through mutagenesis or siRNA-mediated suppression of ZO-3 resulted in increased cyclin D1 proteolysis and G(0)/G(1) cell-cycle retention. This study highlights an important new role for ZO family TJ proteins in regulating epithelial cell proliferation through stabilization of cyclin D1 during mitosis.

  13. Overexpression of cyclins D1 and D3 during estrogen-induced breast oncogenesis in female ACI rats.

    PubMed

    Weroha, S John; Li, Sara Antonia; Tawfik, Ossama; Li, Jonathan J

    2006-03-01

    A common feature of human breast oncogenesis is cell cycle deregulation. The expression of cyclins D1 and D3 was examined during estradiol-17beta (E(2))-induced mammary tumorigenesis in female August Copenhagen Irish (ACI) rats. Low serum E(2) levels ( approximately 60-120 pg/ml) were sufficient to induce mammary gland tumors (MGTs) that remarkably resemble human ductal breast cancer (BC) at the histopathologic and molecular levels. Western blot analysis of the E(2)-induced MGTs revealed a marked rise in cyclins D1 (24-fold), D3 (9-fold) and cdk4 (3-fold) expression compared with age-matched untreated controls. Small focal dysplasias with large, pale staining nuclei were commonly seen at 3-3.6 months, large focal dysplasias, including atypical ductal hyperplasia at 3.6-4.3 months, ductal carcinoma in-situ (DCISs) at 4.3-5.0 months, and 100% incidence of invasive ductal BC/frank tumors at 5-6 months were detected after E(2) treatment. Immunohistochemical analysis of serial sections of focal dysplasias, DCISs and invasive ductal carcinomas showed overexpression of cyclins D1, D3, estrogen receptor-alpha (ERalpha) and progesterone receptor (PR). However, cyclin D3 expression, unlike D1, was confined essentially to early pre-malignant lesions (focal dysplasias and DCISs) and primary MGTs with <1-5% of resting and normal hyperplastic breast cells staining positive. The kinase activity for cyclins D1 and D3, using retinoblastoma (Rb) as a substrate, in E(2)-induced MGTs and their binding to cdk4 was significantly elevated. Semi-quantitative reverse transcriptase PCR analysis of the E(2)-induced MGTs exhibited increased expression of cyclins D1 (2.9-fold) and D3 (1.4-fold) mRNA, indicating that their elevated protein expression was due in part to an increase in mRNA transcription. However, when analyzed by quantitative real-time Q-PCR, these genes were not amplified. These data indicate that in female ACI rat mammary glands, E(2)-induced pre-malignant lesions

  14. BRCA1-IRIS regulates cyclin D1 expression in breast cancer cells

    SciTech Connect

    Nakuci, Enkeleda; Mahner, Sven; DiRenzo, James; ElShamy, Wael M. . E-mail: wael_elshamy@dfci.harvard.edu

    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 in 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.

  15. v-Src Oncogene Induces Trop2 Proteolytic Activation via Cyclin D1.

    PubMed

    Ju, Xiaoming; Jiao, Xuanmao; Ertel, Adam; Casimiro, Mathew C; Di Sante, Gabriele; Deng, Shengqiong; Li, Zhiping; Di Rocco, Agnese; Zhan, Tingting; Hawkins, Adam; Stoyanova, Tanya; Andò, Sebastiano; Fatatis, Alessandro; Lisanti, Michael P; Gomella, Leonard G; Languino, Lucia R; Pestell, Richard G

    2016-11-15

    Proteomic analysis of castration-resistant prostate cancer demonstrated the enrichment of Src tyrosine kinase activity in approximately 90% of patients. Src is known to induce cyclin D1, and a cyclin D1-regulated gene expression module predicts poor outcome in human prostate cancer. The tumor-associated calcium signal transducer 2 (TACSTD2/Trop2/M1S1) is enriched in the prostate, promoting prostate stem cell self-renewal upon proteolytic activation via a γ-secretase cleavage complex (PS1, PS2) and TACE (ADAM17), which releases the Trop2 intracellular domain (Trop2 ICD). Herein, v-Src transformation of primary murine prostate epithelial cells increased the proportion of prostate cancer stem cells as characterized by gene expression, epitope characteristics, and prostatosphere formation. Cyclin D1 was induced by v-Src, and Src kinase induction of Trop2 ICD nuclear accumulation required cyclin D1. Cyclin D1 induced abundance of the Trop2 proteolytic cleavage activation components (PS2, TACE) and restrained expression of the inhibitory component of the Trop2 proteolytic complex (Numb). Patients with prostate cancer with increased nuclear Trop2 ICD and cyclin D1, and reduced Numb, had reduced recurrence-free survival probability (HR = 4.35). Cyclin D1, therefore, serves as a transducer of v-Src-mediated induction of Trop2 ICD by enhancing abundance of the Trop2 proteolytic activation complex. Cancer Res; 76(22); 6723-34. ©2016 AACR. ©2016 American Association for Cancer Research.

  16. A developmentally regulated switch directs regenerative growth of Schwann cells through cyclin D1.

    PubMed

    Kim, H A; Pomeroy, S L; Whoriskey, W; Pawlitzky, I; Benowitz, L I; Sicinski, P; Stiles, C D; Roberts, T M

    2000-05-01

    Sciatic nerve axons in cyclin D1 knockout mice develop normally, become properly ensheathed by Schwann cells, and appear to function normally. However, in the Wallerian degeneration model of nerve injury, the mitotic response of Schwann cells is completely inhibited. The mitotic block is Schwann cell autonomous and developmentally regulated. Rescue analysis (by "knockin" of cyclin E) indicates that D1 protein, rather than regulatory elements of the D1 gene, provides the essential Schwann cell function. Genetic inhibition of the Schwann cell cycle shows that neuronal responses to nerve injury are surprisingly independent of Schwann cell mitotic responses. Even axonal regrowth into the distal zone of a nerve crush injury is not markedly impaired in cyclin D1-/- mice.

  17. The role of pRB, p16 and cyclin D1 in colonic carcinogenesis.

    PubMed

    Ayhan, Semin; Isisag, Aydyn; Saruc, Murat; Nese, Nalan; Demir, Mehmet Akif; Kucukmetin, Nurten Turkel

    2010-01-01

    This study is aimed to investigate abnormal expression of the Rb protein (pRb), p16(INK4a) (p16) and cyclin D1 in colorectal adenomas and adenocarcinomas and to assess the possible alterations in Rb pathway in colorectal carcinogenesis. 44 cases of colorectal adenoma and 44 cases of colorectal adenocarcinoma were examined histopathologically and immunohistochemically using monoclonal antibodies to identify abnormalities of pRb, p16, and cyclin D1 expression. Staining degree of above-mentioned markers was assessed by using a semi-quantitative method in all cases in order to determine any staining differences. In 70.5% of the adenomas and 97.7% of the adenocarcinomas, an overexpression of pRb was found. There was a statistically significant relationship between the immunoreactivity of pRb and villous/tubulovillous types of adenomas (p < 0.05). There was a loss of p16 expression in 84.1% of adenomas and 61.4% of adenocarcinomas. Statistically significantly, the p16 overexpression was not seen in any of tubular adenomas (p < 0.001). Overexpression of cyclin D1 was found in only 9.1% of adenomas, while 31.8% of adenocarcinomas overexpressed this protein. Loss of expression of cyclin D1 was similar in adenomas and adenocarcinomas (27.3% and 25%, respectively). Staining degrees of all three cell cycle proteins were shown to be statistically different in adenomas and adenocarcinomas, for pRb (p = 0.001), for p16 ( p = 0.045), and cyclin D1 ( p = 0.05). Also, there was only a mild agreement with respect to p16 and cyclin D1 relationship between for adenomas ( K = +0.28 p = 0.051) and for adenocarcinomas ( K = +0.35 p = 0.017). Besides, there was no correlation between the expression of pRb, p16, and cyclin D1 and clinicopathological tumor characteristics and prognostic data such as stage or lymph node/liver metastasis. pRb, p16 and cyclin D1 are shown to be aberrantly expressed in both colorectal adenomas and adenocarcinomas. It can be claimed that disturbances in Rb

  18. Cyclin D1 and Ki-67 expression in normal, hyperplastic and neoplastic endometrium

    PubMed Central

    Shevra, CR; Ghosh, A; Kumar, M

    2015-01-01

    Background: Proliferation and differentiation of cancer cells are regulated by various cell cycle promoting and inhibiting factors. Our knowledge about these proteins and mechanisms regulating cell cycle progression has increased dramatically in recent years. Aim: The present study was undertaken to examine the expression profile of cell cycle regulatory proteins in normal proliferative endometrium, hyperplasias (simple, complex and atypical) and endometrial carcinoma in a quantitative approach as also to assess correlations of Cyclin D1 expression with Ki-67 a proliferation marker. Settings and Design: A retrospective case control study in a tertiary referral centre. Materials and Methods: We evaluated and compared the expression profile of Cyclin D1 and Ki-67 expressions in 61 endometrial samples submitted as either endometrial curetting or hysterectomy specimens, which were diagnosed as simple hyperplasia (n =11), complex hyperplasia (n = 13), atypical hyperplasia (n = 7), and endometrial carcinoma (n = 20). Results: There was increased expression of Cyclin D1 and Ki-67 in patients with endometrial carcinoma relative to proliferative endometrium and simple hyperplasia, but there was no such difference between cases of atypical hyperplasia and endometrial carcinoma. Cyclin D1 expression had a positive correlation with Ki-67 expression. Cyclin D1 together with Ki-67 may be a marker for endometrial carcinogenesis and tumor cell proliferation. PMID:25511212

  19. Cyclin D1, retinoblastoma and p16 protein expression in carcinoma of the gallbladder.

    PubMed

    Srivastava, Vineeta; Patel, Brijesh; Kumar, Mohan; Shukla, Mridula; Pandey, Manoj

    2013-01-01

    Cancer of the gallbladder is a relatively rare neoplasm with a poor prognosis. The exact mechanisms of its genesis are not known and very little information is available on molecular events leading to labeling this as an orphan cancer. In this prospective case control study we evaluated the expression of p16, pRb and cyclin D1 by immunohistochemistry to study the G1-S cell-cycle check point and its possible role in gallbladder carcinogenesis. A total of 25 patients with gallbladder carcinoma (group I), 25 with cholelithiasis (group II) and 10 normal controls. were enrolled. Cyclin D1 expression was seen in 10 (40%) patients each with carcinoma and cholelithiasis while only in 2 (20%) of the normal gallbladders but differences were not statistically significant (p value=0.488). p16 was expressed in 12% patients of carcinoma of the gallbladder and 28% of cholelithiasis, however this difference was not statistically significant (p value=0.095). Retinoblastoma protein was found to be expressed in 50% of normal gallbladders and 6 (24%) of carcinoma and 8 (32%) of gallstones. The present study failed to demonstrate any conclusive role of cyclin D1/RB/ p16 pathway in carcinoma of the gallbladder. The positive relation observed between tumor metastasis and cyclinD1 expression and p16 with nodal metastasis suggested that higher cyclin D1/p16 expression may act as a predictive biomarker for aggressive behavior of gallbladder malignancies.

  20. Reduced expression of cyclin D2 is associated with poor recurrence-free survival independent of cyclin D1 in stage III non-small cell lung cancer.

    PubMed

    Ko, Eunkyung; Kim, Yujin; Park, Seong-Eun; Cho, Eun Yoon; Han, Jungho; Shim, Young Mog; Park, Joobae; Kim, Duk-Hwan

    2012-08-01

    Compared to well-known function of cyclin D1 in lung cancer, the role of cyclin D2 is not clear. This study was aimed at understanding the clinicopathological significance of cyclin D2 in primary non-small cell lung cancer (NSCLC). We retrospectively analyzed expression statuses of cyclin D1, cyclin D2, p16, p21, p27, Ki-67, and phospho-pRb (Ser-807/811) using immunohistochemistry in 626 NSCLCs. Cyclin D2 was expressed in normal lung tissue, and its expression was reduced in 170 (27%) of 626 NSCLCs with a median duration of follow-up of 64 months. Mean phospho-pRb (Ser-807/811) levels were not associated with expression levels of cyclin D2 (P=0.15). The relationship between recurrence and the reduced expression of cyclin D2 was not homogenous by stage (Breslow-Day test for homogeneity, P=0.04). Reduced expression of cyclin D2 was not associated with patient's prognosis in 370 stage I, 112 stage II, and 18 stage IV NSCLCs. However, for 126 stage III NSCLCs, reduced expression of cyclin D2 was adversely associated with recurrence-free survival (RFS) (hazard ratio [HR]=3.71, 95% CI=1.54-13.17; P=0.01), independent of histology and expression of cyclin D1. The reduced expression of cyclin D2 was not associated with the overexpression of cyclin D1 (P=0.65). The present study suggests that reduced expression of cyclin D2 in stage III NSCLC may be associated with poor RFS. And, cyclin D2 may have a distinct role from cyclin D1 in NSCLC. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  1. Cyclin D1 expression in acral melanoma: a case control study in Sarawak.

    PubMed

    Ibrahim, Zainal Abidin; Narihan, M Zulkarnaen A; Ojep, Dk Norlida A; Soosay, Ashley Edward Roy; Pan, Kok Long

    2012-12-01

    Acral melanoma has been reported to have distinctive clinical presentation and ethnic distribution compared to other histological types of malignant melanoma. Acral melanoma also exhibits distinctive focused gene amplifications, including cyclin D1 overexpression. We reviewed archived histological material of malignant melanoma in the Sarawak General Hospital from year 2004 to 2010. 43 tumours, comprising 28 acral melanoma and 15 non-acral melanoma, had sufficient material to be included in the study. The majority (36%) of acral melanoma tumours occurred in the heel. The tumours were analyzed for cyclin D1 expression by immunohistochemistry. 68% of acral melanoma were cyclin D1 positive compared to a positivity of 33% in non-acral tumours. This difference was statistically significant (p < 0.05). This finding may improve the histological diagnosis of acral melanoma and detection of positive resection margins.

  2. Immunohistochemical comparison of cyclin D1 and P16 in odontogenic keratocyst and unicystic ameloblastoma.

    PubMed

    Razavi, Seyed Mohammad; Poursadeghi, Hamid; Aminzadeh, Atousa

    2013-03-01

    The different growth mechanism and biologic behavior of the odontogenic keratocyst (OKC) compared to other odontogenic cysts might be related to the proliferating capacity of its epithelium. In this study, the aim was to evaluate and compare the distribution and staining intensity of P16 and cyclin D1 in OKC and unicystic ameloblastoma (UA). In this descriptive analytic study, hematoxylin- and eosin-stained slides of OKCs and UAs available from the archives of the oral pathology laboratory of the Esfahan School of Dentistry were examined. Twenty-five noninflamed solitary odontogenic keratocysts and 25 unicystic ameloblastomas (of either type) were selected and stained immunohistochemically. Distribution and staining intensity score (SID score) for P16- and cyclin D1-positive cells was calculated in both groups. Results were analyzed statistically with Wilcoxon, Friedman, and Mann-Whitney tests; P < 0.05 was considered significant. The highest expression of Cyclin D1-positive cells was seen in the suprabasal layer of keratocysts (P < 0.05) and in the peripheral layer of UAs (P < 0.05). Likewise, the highest expression of P16-positive cells was observed in the basal and suprabasal layers of keratocysts (P > 0.05) and central portions of UAs (P > 0.05). Expression of Cyclin D1 was higher in UAs compared to keratocyts (P < 0.05), although P16 did not show a significant difference between the two study groups (P > 0.05). Cyclin D1 did show a higher staining intensity in UAs compared to the keratocysts, although the expression of P16 was similar in the studied groups. The invasive growth of OKC might be related to the state of expression of cyclin D1 and P16 in the epithelium of this cyst.

  3. Evaluation of Cyclin D1 expression in Head and Neck Squamous Cell Carcinoma

    PubMed Central

    Dhingra, Vishal; Verma, Jyoti; Misra, Vatsala; Srivastav, Sapan

    2017-01-01

    Introduction Squamous Cell Carcinoma (SCC) is an aggressive epithelial malignancy of the upper aero digestive tract and comprises 90% of all Head and Neck Squamous Cell Carcinoma (HNSCC). It is the sixth leading cancer worldwide with approximately 600,000 cases reported annually. It is one of the most common cancers in India. Tumour Lymph Node and Metastases (TNM) staging has been the most useful indicator to predict prognosis in HNSCC but recently various biomolecular markers have potentially offered new methods for early diagnosis and treatment alternatives for HNSCC patients; one amongst them being cyclin D1. Aim This study has been undertaken to evaluate expression of cyclin D1 in HNSCC cases and to find out its association with various pathological prognostic factors. Materials and Methods A 48 formalin fixed paraffin embedded tumour sections, stained with Haematoxylin & Eosin were graded and staged. Immunohistochemistry for cyclin D1 was evaluated as Extent Score (ES), Intensity Score (IS) and Total Score (TS) was calculated. Statistical Analysis All the relevant data collected was transferred on to the excel sheet. Chi square test with and without Yate’s correction was used to compare various parameters. The p-value ≤ 0.05 was taken as critical level of significance. Results A significant association was seen between TS of Cyclin D1 expression with tumour stage and with lymph node metastasis but not with grade. Conclusion Higher Cyclin D1 expression is associated with higher tumour stage and lymph node metastasis. Therefore, there is value of analysing cyclin D1 amplification and expression, for prognostic evaluation. This may also be further used for targeted therapy in head and neck cancers. PMID:28384866

  4. Downregulation of cyclin D1 sensitizes cancer cells to MDM2 antagonist Nutlin-3

    PubMed Central

    Li, Xuhui; Eilers, Grant; He, Quan; Liu, Lili; Wu, Yeqing; Wu, Yuehong; Yu, Wei; Fletcher, Jonathan A.; Ou, Wen-Bin

    2016-01-01

    The MDM2-p53 pathway has a prominent oncogenic function in the pathogenesis of various cancers. Nutlin-3, a small-molecule antagonist of MDM2-p53 interaction, inhibits proliferation in cancer cells with wild-type p53. Herein, we evaluate the expression of MDM2, both the full length and a splicing variant MDM2-A, and the sensitivity of Nutlin-3 in different cancer cell lines. Included are seven cell lines with wild-type p53 (four mesothelioma, one breast cancer, one chondrosarcoma, and one leiomyosarcoma), two liposarcoma cell lines harboring MDM2 amplification and wild-type p53, and one mesothelioma cell line harboring a p53 point mutation. Nutlin-3 treatment increased expression of cyclin D1, MDM2, and p53 in cell lines with wild-type p53. Additive effects were observed in cells containing wild-type p53 through coordinated attack on MDM2-p53 binding and cyclin D1 by lentivirual shRNA knockdown or small molecule inhibition, as demonstrated by immunoblots and cell viability analyses. Further results demonstrate that MDM2 binds to cyclin D1, and that an increase in cyclin D1 expression after Nutlin-3 treatment is correlated with expression and ubiquitin E3-ligase activity of MDM2. MDM2 and p53 knockdown experiments demonstrated inhibition of cyclin D1 by MDM2 but not p53. These results indicate that combination inhibition of cyclin D1 and MDM2-p53 binding warrants clinical evaluation as a novel therapeutic strategy in cancer cells harboring wild-type p53. PMID:27129163

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

    SciTech Connect

    Chu, Xiufeng; Zhang, Ting; Wang, Jie; Li, Meng; Zhang, Xiaolei; Tu, Jing; Sun, Shiqin; Chen, Xiangmei; Lu, Fengmin

    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 have 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

  6. The Role of Cyclin D1 in the Chemoresistance of Mantle Cell Lymphoma

    DTIC Science & Technology

    2016-09-01

    AWARD NUMBER: W81XWH-15-1-0297 TITLE: The Role of Cyclin D1 in the Chemoresistance of Mantle Cell Lymphoma PRINCIPAL INVESTIGATOR: Vu Ngo...SUBTITLE The Role of Cyclin D1 in the Chemoresistance of Mantle Cell Lymphoma 5a. CONTRACT NUMBER W81XWH-15-1-0297 5b. GRANT NUMBER W81XWH-15-1-0297...STATEMENT Approved for Public Release; Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Mantle cell lymphoma (MCL) is an aggressive B

  7. Replication licensing promotes cyclin D1 expression and G1 progression in untransformed human cells

    PubMed Central

    Liu, Peijun; Slater, Damien M.; Lenburg, Marc; Nevis, Kathleen; Cook, Jeanette Gowen; Vaziri, Cyrus

    2011-01-01

    Defects in DNA replication are implicated as early and causal events in malignancy. However, the immediate effects of impaired DNA replication licensing on cell cycle progression of non-malignant human cells are unknown. Therefore, we have investigated the acute effects of Mcm7 ablation using synchronized cultures of untransformed Human Dermal Fibroblasts (HDF). Mcm7 ablation elicited a G1 delay associated with impaired activation of CDK4 and CDK2 and reduced Rb phosphorylation. The cell cycle delay of Mcm7-ablated cells was not associated with a DNA damage response. However, levels of cyclin D1 mRNA were specifically reduced and binding of RNA Polymerase II to the CYCD1 promoter was decreased in Mcm7-depleted cells. Similar to Mcm7-deficiency, Mcm2- or Cdc6-depletion led to impaired cyclin D expression. Ectopic overexpression of Cdc6 in quiescent cells promoted cyclin D1 expression, CDK4 activation and G1 progression. Therefore timely and efficient expression of cyclin D1 during G1 phase requires replication licensing. Reconstitution of cyclin D1 expression was insufficient to correct the G1 delay of Mcm7-depleted cells, indicating that additional cell cycle events during G1 are dependent on replication licensing. However, ectopic expression of the HPV-E7 oncoprotein, and the resulting bypass of the requirement for cyclin D1-Rb signaling enabled Mcm7-depleted cells to enter S-phase. HPV-E7-induced S-phase entry of Mcm7-depleted cells led to a DNA damage response, a hallmark of pre-malignancy. Taken together, our results suggest the existence of a ‘replication licensing restriction point’ that couples pre-RC assembly with G1 progression in normal cells to minimize replication stress, DNA damage and tumorigenesis. PMID:19106611

  8. Antisense inhibition of cyclin D1 expression is equivalent to flavopiridol for radiosensitization of zebrafish embryos

    SciTech Connect

    McAleer, Mary Frances; Duffy, Kevin T.; Davidson, William R.; Kari, Gabor; Dicker, Adam P.; Rodeck, Ulrich; Wickstrom, Eric . E-mail: eric@tesla.jci.tju.edu

    2006-10-01

    Purpose: Flavopiridol, a small molecule pan-cyclin inhibitor, has been shown to enhance Radiation response of tumor cells both in vitro and in vivo. The clinical utility of flavopiridol, however, is limited by toxicity, previously attributed to pleiotropic inhibitory effects on several targets affecting multiple signal transduction pathways. Here we used zebrafish embryos to investigate radiosensitizing effects of flavopiridol in normal tissues. Methods and Materials: Zebrafish embryos at the 1- to 4-cell stage were treated with 500 nM flavopiridol or injected with 0.5 pmol antisense hydroxylprolyl-phosphono nucleic acid oligomers to reduce cyclin D1 expression, then subjected to ionizing radiation (IR) or no radiation. Results: Flavopiridol-treated embryos demonstrated a twofold increase in mortality after exposure to 40 Gy by 96 hpf and developed distinct radiation-induced defects in midline development (designated as the 'curly up' phenotype) at higher rates when compared with embryos receiving IR only. Cyclin D1-deficient embryos had virtually identical IR sensitivity profiles when compared with embryos treated with flavopiridol. This was particularly evident for the IR-induced curly up phenotype, which was greatly exacerbated by both flavopriridol and cyclin D1 downregulation. Conclusions: Treatment of zebrafish embryos with flavopiridol enhanced radiation sensitivity of zebrafish embryos to a degree that was very similar to that associated with downregulation of cyclin D1 expression. These results are consistent with the hypothesis that inhibition of cyclin D1 is sufficient to account for the radiosensitizing action of flavopiridol in the zebrafish embryo vertebrate model.

  9. 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.

  10. Understanding and modulating cyclin-dependent kinase inhibitor specificity: molecular modeling and biochemical evaluation of pyrazolopyrimidinones as CDK2/cyclin A and CDK4/cyclin D1 inhibitors

    NASA Astrophysics Data System (ADS)

    Rossi, Karen A.; Markwalder, Jay A.; Seitz, Steven P.; Chang, Chong-Hwan; Cox, Sarah; Boisclair, Michael D.; Brizuela, Leonardo; Brenner, Stephen L.; Stouten, Pieter F. W.

    2005-02-01

    Cyclin-dependent kinases (CDKs) play a key role in regulating the cell cycle. The cyclins, their activating agents, and endogenous CDK inhibitors are frequently mutated in human cancers, making CDKs interesting targets for cancer chemotherapy. Our aim is the discovery of selective CDK4/cyclin D1 inhibitors. An ATP-competitive pyrazolopyrimidinone CDK inhibitor was identified by HTS and docked into a CDK4 homology model. The resulting binding model was consistent with available SAR and was validated by a subsequent CDK2/inhibitor crystal structure. An iterative cycle of chemistry and modeling led to a 70-fold improvement in potency. Small substituent changes resulted in large CDK4/CDK2 selectivity changes. The modeling revealed that selectivity is largely due to hydrogen-bonded interactions with only two kinase residues. This demonstrates that small differences between enzymes can efficiently be exploited in the design of selective inhibitors.

  11. 2,3,7,8-Tetrachlorodibenzo-p-dioxin stimulates proliferation of HAPI microglia by affecting the Akt/GSK-3β/cyclin D1 signaling pathway.

    PubMed

    Xu, Guangfei; Li, Yuanye; Yoshimoto, Katsuhiko; Wu, Qiyun; Chen, Gang; Iwata, Takeo; Mizusawa, Noriko; Wan, Chunhua; Nie, Xiaoke

    2014-01-30

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental toxin that induces apoptosis of neurons and a pro-inflammatory response in microglial cells. First, we found that TCDD induced proliferation of HAPI microglial cells in a dose- and time-dependent manner. Flow cytometry analysis showed that this proliferation by TCDD was due to mainly enhancing the G1 to S phase transition. Next, it was found that TCDD treatment led to up-regulation of cyclin D1, which induces cell cycle progression from G1 to S phase, in a time-dependent manner. As for molecular mechanism, we revealed that TCDD was capable of inducing Akt phosphorylation and activation, resulting in phosphorylation and inactivation of glycogen synthase kinase-3β (GSK-3β). Inactivated GSK-3β attenuated proteasomal degradation of cyclin D1 by reducing Thr(286)-phosphorylated cyclin D1 levels. Moreover, inactivated GSK-3β increased cyclin D1 gene transcription by increasing its transcription factor β-catenin in the nucleus. Further, blockage of phosphoinositide 3-kinase/Akt kinase with their specific inhibitors, LY294002 and Akt 1/2 kinase inhibitor, significantly reduced TCDD-enhanced proliferation of HAPI microglial cells. In conclusion, TCDD stimulates proliferation of HAPI microglial cells by affecting the Akt/GSK-3β/cyclin D1 signaling pathway.

  12. Inhibition of cyclin D1 expression by androgen receptor in breast cancer cells--identification of a novel androgen response element.

    PubMed

    Lanzino, Marilena; Sisci, Diego; Morelli, Catia; Garofalo, Cecilia; Catalano, Stefania; Casaburi, Ivan; Capparelli, Claudia; Giordano, Cinzia; Giordano, Francesca; Maggiolini, Marcello; Andò, Sebastiano

    2010-09-01

    Cyclin D1 gene (CCND1) is a critical mitogen-regulated cell-cycle control element whose transcriptional modulation plays a crucial role in breast cancer growth and progression. Here we demonstrate that the non-aromatizable androgen 5-α-dihydrotestosterone (DHT) inhibits endogenous cyclin D1 expression, as evidenced by reduction of cyclin D1 mRNA and protein levels, and decrease of CCND1-promoter activity, in MCF-7 cells. The DHT-dependent inhibition of CCND1 gene activity requires the involvement and the integrity of the androgen receptor (AR) DNA-binding domain. Site directed mutagenesis, DNA affinity precipitation assay, electrophoretic mobility shift assay and chromatin immunoprecipitation analyses indicate that this inhibitory effect is ligand dependent and it is mediated by direct binding of AR to an androgen response element (CCND1-ARE) located at -570 to -556-bp upstream of the transcription start site, in the cyclin D1 proximal promoter. Moreover, AR-mediated repression of the CCND1 involves the recruitment of the atypical orphan nuclear receptor DAX1 as a component of a multiprotein repressor complex also embracing the participation of Histone Deacetylase 1. In conclusion, identification of the CCND1-ARE allows defining cyclin D1 as a specific androgen target gene in breast and might contribute to explain the molecular basis of the inhibitory role of androgens on breast cancer cells proliferation.

  13. Placental estrogen suppresses cyclin D1 expression in the nonhuman primate fetal adrenal cortex.

    PubMed

    Dumitrescu, Adina; Aberdeen, Graham W; Pepe, Gerald J; Albrecht, Eugene D

    2014-12-01

    We have previously shown that estrogen selectively suppresses growth of the fetal zone of the baboon fetal adrenal cortex, which produces the C19-steroid precursors, eg, dehydroepiandrosterone sulfate, which are aromatized to estrogen within the placenta. In the present study, we determined whether fetal adrenal expression of cell cycle regulators are altered by estrogen and thus provide a mechanism by which estrogen regulates fetal adrenocortical development. Cyclin D1 mRNA levels in the whole fetal adrenal were increased 50% (P < .05), and the number of cells in the fetal adrenal definitive zone expressing cyclin D1 protein was increased 2.5-fold (P < .05), whereas the total number of cells in the fetal zone and fetal serum dehydroepiandrosterone sulfate levels were elevated 2-fold (P < .05) near term in baboons in which fetal serum estradiol levels were decreased by 95% (P < .05) after maternal administration of the aromatase inhibitor letrozole and restored to normal by concomitant administration of letrozole plus estradiol throughout second half of gestation. However, fetal adrenocortical expression of cyclin D2, the cyclin-dependent kinase (Cdk)-2, Cdk4, and Cdk6, and Cdk regulatory proteins p27(Kip1) and p57(Kip2) were not changed by letrozole or letrozole plus estradiol administration. We suggest that estrogen controls the growth of the fetal zone of the fetal adrenal by down-regulating cyclin D1 expression and thus proliferation of progenitor cells within the definitive zone that migrate to the fetal zone. We propose that estrogen restrains growth and function of the fetal zone via cyclin D1 to maintain estrogen levels in a physiological range during primate pregnancy.

  14. Placental Estrogen Suppresses Cyclin D1 Expression in the Nonhuman Primate Fetal Adrenal Cortex*

    PubMed Central

    Dumitrescu, Adina; Aberdeen, Graham W.; Pepe, Gerald J.

    2014-01-01

    We have previously shown that estrogen selectively suppresses growth of the fetal zone of the baboon fetal adrenal cortex, which produces the C19-steroid precursors, eg, dehydroepiandrosterone sulfate, which are aromatized to estrogen within the placenta. In the present study, we determined whether fetal adrenal expression of cell cycle regulators are altered by estrogen and thus provide a mechanism by which estrogen regulates fetal adrenocortical development. Cyclin D1 mRNA levels in the whole fetal adrenal were increased 50% (P < .05), and the number of cells in the fetal adrenal definitive zone expressing cyclin D1 protein was increased 2.5-fold (P < .05), whereas the total number of cells in the fetal zone and fetal serum dehydroepiandrosterone sulfate levels were elevated 2-fold (P < .05) near term in baboons in which fetal serum estradiol levels were decreased by 95% (P < .05) after maternal administration of the aromatase inhibitor letrozole and restored to normal by concomitant administration of letrozole plus estradiol throughout second half of gestation. However, fetal adrenocortical expression of cyclin D2, the cyclin-dependent kinase (Cdk)-2, Cdk4, and Cdk6, and Cdk regulatory proteins p27Kip1 and p57Kip2 were not changed by letrozole or letrozole plus estradiol administration. We suggest that estrogen controls the growth of the fetal zone of the fetal adrenal by down-regulating cyclin D1 expression and thus proliferation of progenitor cells within the definitive zone that migrate to the fetal zone. We propose that estrogen restrains growth and function of the fetal zone via cyclin D1 to maintain estrogen levels in a physiological range during primate pregnancy. PMID:25247468

  15. Schlafen-1 causes a cell cycle arrest by inhibiting induction of cyclin D1.

    PubMed

    Brady, Gareth; Boggan, Louise; Bowie, Andrew; O'Neill, Luke A J

    2005-09-02

    Schlafen-1 (Slfn-1), the prototypic member of the Schlafen family of proteins, was described as an inducer of growth arrest in T-lymphocytes and causes a cell cycle arrest in NIH3T3 fibroblasts prior to the G1/S transition. How Slfn-1 exerts its effects on the cell cycle is not currently known. We report that synchronized murine fibroblasts expressing Slfn-1 do not exit G1 when stimulated with fetal calf serum, platelet-derived growth factor BB (PDGF-BB) or epidermal growth factor (EGF). The induction of cyclin D1 by these stimuli was blocked in the presence of Slfn-1 as were all downstream cell cycle processes. Overexpression of cyclin D1 in growth-arrested, Slfn-1-expressing cells induced an increase in cell growth consistent with this protein being the biological target of Slfn-1. Activation of the mitogen-activated protein kinase pathway by EGF or phorbol 12-myristate 13-acetate was unaffected by Slfn-1 expression. PDGF signaling was, however, almost completely blocked. This was due to a lack of PDGF receptor expression in Slfn-1-expressing cells consistent with Slfn-1 blocking the cell cycle in G1 where PDGF receptor expression is normally down-regulated. Finally, overexpression of Slfn-1 inhibited the activation of the cyclin D1 promoter. Slfn-1 therefore causes a cell cycle arrest during G1 by inhibiting induction of cyclin D1 by mitogens.

  16. Cyclin D1 overexpression in proliferation centres of small lymphocytic lymphoma/chronic lymphocytic leukaemia.

    PubMed

    Teixeira Mendes, Larissa Sena; Peters, Natalie; Attygalle, Ayoma D; Wotherspoon, Andrew

    2017-10-01

    The recent publication reviewing the updated WHO classification commented on the presence of cyclin D1-positive cells in the proliferation centres (PC) of small lymphocytic lymphoma/chronic lymphocytic leukaemia (SLL/CLL). The figure quoted was 30%, which appeared higher than our experience. To assess cyclin D1 expression in PC of SLL/CLL cases, we performed a review of SLL/CLL cases diagnosed at the Royal Marsden Hospital between 1996 and 2009. Of 105 SLL/CLL cases, 16.2% showed expression of cyclin D1 in PC with none carrying the translocation t(11;14)(q13;q32). Our study and a review of the published literature suggest that this phenomenon occurs with a significantly lower prevalence than that described in the recent review of the updated WHO classification. We confirm that cyclin D1 expression is confined to PC with the typical small lymphocytes being negative. This finding is apparently unrelated to the translocation involving CCND1 and IGH genes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  17. Epigenetically altered miR-193b targets cyclin D1 in prostate cancer

    PubMed Central

    Kaukoniemi, Kirsi M; Rauhala, Hanna E; Scaravilli, Mauro; Latonen, Leena; Annala, Matti; Vessella, Robert L; Nykter, Matti; Tammela, Teuvo L J; Visakorpi, Tapio

    2015-01-01

    Micro-RNAs (miRNA) are important regulators of gene expression and often differentially expressed in cancer and other diseases. We have previously shown that miR-193b is hypermethylated in prostate cancer (PC) and suppresses cell growth. It has been suggested that miR-193b targets cyclin D1 in several malignancies. Here, our aim was to determine if miR-193b targets cyclin D1 in prostate cancer. Our data show that miR-193b is commonly methylated in PC samples compared to benign prostate hyperplasia. We found reduced miR-193b expression (P < 0.05) in stage pT3 tumors compared to pT2 tumors in a cohort of prostatectomy specimens. In 22Rv1 PC cells with low endogenous miR-193b expression, the overexpression of miR-193b reduced CCND1mRNA levels and cyclin D1 protein levels. In addition, the exogenous expression of miR-193b decreased the phosphorylation level of RB, a target of the cyclin D1-CDK4/6 pathway. Moreover, according to a reporter assay, miR-193b targeted the 3’UTR of CCND1 in PC cells and the CCND1 activity was rescued by expressing CCND1 lacking its 3’UTR. Immunohistochemical analysis of cyclin D1 showed that castration-resistant prostate cancers have significantly (P = 0.0237) higher expression of cyclin D1 compared to hormone-naïve cases. Furthermore, the PC cell lines 22Rv1 and VCaP, which express low levels of miR-193b and high levels of CCND1, showed significant growth retardation when treated with a CDK4/6 inhibitor. In contrast, the inhibitor had no effect on the growth of PC-3 and DU145 cells with high miR-193b and low CCND1 expression. Taken together, our data demonstrate that miR-193b targets cyclin D1 in prostate cancer. PMID:26129688

  18. P16, EGFR, Cyclin D1, and p53 Staining Patterns for Inverted Papilloma

    PubMed Central

    Lin, Giant C.; Scheel, Adam; Akkina, Sarah; Chinn, Steven; Graham, Martin; Komarck, Christine; Walline, Heather; McHugh, Jonathan B.; Prince, Mark E.; Carey, Thomas; Zacharek, Mark A.

    2014-01-01

    Introduction We aim to better characterize the staining patterns of inverted papilloma (IP) with and without carcinoma by performing immunohistochemistry for p16, EGFR (Epidermal Growth Factor Receptor), p53, and Cyclin D1 antibodies on a large patient cohort. Methods One hundred and sixty-two IP specimens from 122 patients treated at the University of Michigan between 1996 and 2011. Twenty-two specimens contained carcinoma. Tumor was extracted for construction of two tissue microarrays and stained for p16, EGFR, p53, and Cyclin D1. Tumor staining intensity and percentage staining were scored. Results Mean percentage staining for IP and IP with carcinoma was 12% versus 7% for p16 (no statistical significance, NS), 20% versus 34% for EGFR (NS), 4% versus 24% for p53 (p<0.001), and 17% versus 21% for Cyclin D1 (NS). Benign disease was positive for p16 in 64%, EGFR in 50%, p53 in 30%, and Cyclin D1 in 76%. Inverted papilloma with carcinomatous degeneration was positive for p16 in 14%, EGFR in 71%, p53 in 62%, and Cyclin D1 in 76%. This is statistically significant for differences between IP and IP carcinoma for p16 and p53 staining only. Conclusion Important characteristic staining pattern for inverted papilloma with and without carcinoma are highlighted in this study. Unlike recent trends in HPV-related head and neck malignancies, low expression of p16 is a marker for malignancy in this series. Positive staining for p53 correlates with the development of carcinoma in inverted papilloma. PMID:24039221

  19. Cyclin D1 and Ki-67 expression correlates to tumor staging in tongue squamous cell carcinoma

    PubMed Central

    de Carli, Marina-Lara; Sperandio, Felipe-Fornias; Hanemann, João-Adolfo-Costa; Pereira, Alessandro-Antônio-Costa

    2015-01-01

    Background The immunohistochemical expression of Cyclin D1 and Ki-67 were analyzed in tongue squamous cell carcinomas (SCC), relating them to the clinical and morphological exhibition of these tumors. Material and Methods Twenty-nine patients fulfilled the inclusion criteria; clinical data included gender, age, ethnicity and use of licit drugs such as alcohol and tobacco. The TNM staging and histopathological differentiation grading was assessed for each case. In addition, T1 patients were gathered with T2 patients; and T3 patients were gathered with T4 patients to assemble two distinct groups: (T1/T2) and (T3/T4). Results The mean follow-up time was 24 months and 30% of the patients died as a consequence of the disease, while 23.3% lived with the disease and 46.7% lived lesion-free. T1 and T2 tumors showed statistically lesser Ki-67 and Cyclin D1 staining when compared to T3 and T4 tumors. Conclusions Ki-67 and Cyclin D1 pose as auxiliary tools when determining the progression of tongue SCC at the time of diagnosis. Key words:Carcinoma, squamous cell, cyclin D, immunohistochemistry, Ki-67 antigen, prognosis. PMID:26449430

  20. Cytoplasmic cyclin D1 regulates cell invasion and metastasis through the phosphorylation of paxillin

    PubMed Central

    Fusté, Noel P.; Fernández-Hernández, Rita; Cemeli, Tània; Mirantes, Cristina; Pedraza, Neus; Rafel, Marta; Torres-Rosell, Jordi; Colomina, Neus; Ferrezuelo, Francisco; Dolcet, Xavier; Garí, Eloi

    2016-01-01

    Cyclin D1 (Ccnd1) together with its binding partner Cdk4 act as a transcriptional regulator to control cell proliferation and migration, and abnormal Ccnd1·Cdk4 expression promotes tumour growth and metastasis. While different nuclear Ccnd1·Cdk4 targets participating in cell proliferation and tissue development have been identified, little is known about how Ccnd1·Cdk4 controls cell adherence and invasion. Here, we show that the focal adhesion component paxillin is a cytoplasmic substrate of Ccnd1·Cdk4. This complex phosphorylates a fraction of paxillin specifically associated to the cell membrane, and promotes Rac1 activation, thereby triggering membrane ruffling and cell invasion in both normal fibroblasts and tumour cells. Our results demonstrate that localization of Ccnd1·Cdk4 to the cytoplasm does not simply act to restrain cell proliferation, but constitutes a functionally relevant mechanism operating under normal and pathological conditions to control cell adhesion, migration and metastasis through activation of a Ccnd1·Cdk4-paxillin-Rac1 axis. PMID:27181366

  1. ATF7 is stabilized during mitosis in a CDK1-dependent manner and contributes to cyclin D1 expression

    PubMed Central

    Schaeffer, Etienne; Vigneron, Marc; Sibler, Annie-Paule; Oulad-Abdelghani, Mustapha; Chatton, Bruno; Donzeau, Mariel

    2015-01-01

    The transcription factor ATF7 undergoes multiple post-translational modifications, each of which has distinct effects upon ATF7 function. Here, we show that ATF7 phosphorylation on residue Thr112 exclusively occurs during mitosis, and that ATF7 is excluded from the condensed chromatin. Both processes are CDK1/cyclin B dependent. Using a transduced neutralizing monoclonal antibody directed against the Thr112 epitope in living cells, we could demonstrate that Thr112 phosphorylation protects endogenous ATF7 protein from degradation, while it has no effect on the displacement of ATF7 from the condensed chromatin. The crucial role of Thr112 phosphorylation in stabilizing ATF7 protein during mitosis was confirmed using phospho-mimetic and phospho-deficient mutants. Finally, silencing ATF7 by CRISPR/Cas9 technology leads to a decrease of cyclin D1 protein expression levels. We propose that mitotic stabilized ATF7 protein re-localizes onto chromatin at the end of telophase and contributes to induce the cyclin D1 gene expression. PMID:26101806

  2. ATF7 is stabilized during mitosis in a CDK1-dependent manner and contributes to cyclin D1 expression.

    PubMed

    Schaeffer, Etienne; Vigneron, Marc; Sibler, Annie-Paule; Oulad-Abdelghani, Mustapha; Chatton, Bruno; Donzeau, Mariel

    2015-01-01

    The transcription factor ATF7 undergoes multiple post-translational modifications, each of which has distinct effects upon ATF7 function. Here, we show that ATF7 phosphorylation on residue Thr112 exclusively occurs during mitosis, and that ATF7 is excluded from the condensed chromatin. Both processes are CDK1/cyclin B dependent. Using a transduced neutralizing monoclonal antibody directed against the Thr112 epitope in living cells, we could demonstrate that Thr112 phosphorylation protects endogenous ATF7 protein from degradation, while it has no effect on the displacement of ATF7 from the condensed chromatin. The crucial role of Thr112 phosphorylation in stabilizing ATF7 protein during mitosis was confirmed using phospho-mimetic and phospho-deficient mutants. Finally, silencing ATF7 by CRISPR/Cas9 technology leads to a decrease of cyclin D1 protein expression levels. We propose that mitotic stabilized ATF7 protein re-localizes onto chromatin at the end of telophase and contributes to induce the cyclin D1 gene expression.

  3. [The expression and significance of Pin1 and CyclinD1 in adult papilloma of larynx].

    PubMed

    Fan, Guoliang; Wang, Dali; Fan, Xinlong; Wang, Tie

    2009-12-01

    To study the expression and relationship of Pin1 and CyclinD1 in adult papilloma of larynx, and the effect of both in laryngeal papilloma's canceration. Ninety-two cases of paraffin section with immunoperoxidase (SP) staining method was used to detect the distribution of Pin1 and CyclinD1 in 10 cases of laryngeal normal epithelial tissue, 39 cases of laryngeal papilloma, 27 cases of laryngeal papilloma with middle, severe atypical hyperplasia and 16 cases of laryngeal carcinoma. The distribution of Pin1 and CyclinD1 increased gradually from laryngeal normal epithelial tissue to laryngeal carcinoma (P<0.05); No difference of the expression of CyclinD1 (not including Pin1, for Pin1, P=0.009) was found between laryngeal papilloma and laryngeal papilloma with middle, severe atypical hyperplasia (P>0.0125), but there had significant difference of the expression of Pin1 and CyclinD1 among the rest groups; There was significantly direct correlation between the expression of Pin1 and CyclinD1 (P<0.05). The hyper-expressions of Pin1 and CyclinD1 may play a key role in laryngeal papilloma's malignant change. Pin1 up-regulating the expressions of cyclinD1 possibly participate in its malignant change.

  4. Mantle cell lymphoma in cyclin D1 transgenic mice with Bim-deficient B cells.

    PubMed

    Katz, Samuel G; Labelle, James L; Meng, Hailong; Valeriano, Regina P; Fisher, Jill K; Sun, Heather; Rodig, Scott J; Kleinstein, Steven H; Walensky, Loren D

    2014-02-06

    Mantle cell lymphoma (MCL) is a highly aggressive B-cell lymphoma resistant to conventional chemotherapy. Although defined by the characteristic t(11;14) translocation, MCL has not been recapitulated in transgenic mouse models of cyclin D1 overexpression alone. Indeed, several genetic aberrations have been identified in MCL that may contribute to its pathogenesis and chemoresistance. Of particular interest is the frequent biallelic deletion of the proapoptotic BCL-2 family protein BIM. BIM exerts its pro-death function via its α-helical BH3 death domain that has the dual capacity to inhibit antiapoptotic proteins such as BCL-2 and MCL-1 and directly trigger proapoptotic proteins such as the mitochondrial executioner protein BAX. To evaluate a functional role for Bim deletion in the pathogenesis of MCL, we generated cyclin D1-transgenic mice harboring Bim-deficient B cells. In response to immunization, Eμ(CycD1)CD19(CRE)Bim(fl/fl) mice manifested selective expansion of their splenic mantle zone compartment. Three distinct immune stimulation regimens induced lymphomas with histopathologic and molecular features of human MCL in a subset of mice. Thus, deletion of Bim in B cells, in the context of cyclin D1 overexpression, disrupts a critical control point in lymphoid maturation and predisposes to the development of MCL. This genetic proof of concept for MCL pathogenesis suggests an opportunity to reactivate the death pathway by pharmacologic mimicry of proapoptotic BIM.

  5. The role of MIF, cyclinD1 and ERK in the development of pulmonary hypertension in broilers.

    PubMed

    Li, Haoyun; Wang, Yanmei; Chen, Lingli; Han, Lijuan; Li, Lifang; He, Han; Li, Yuan; Huang, Nan; Ren, Hao; Pei, Fangying; Li, Guilan; Cheng, Jia; Wang, Wenkui

    2017-04-01

    Pulmonary hypertension (PH) is a major disease in the broiler breeding industry. During PH, the pulmonary artery undergoes remodelling, which is caused by pulmonary vascular smooth muscle cell proliferation. CyclinD1 regulates cell proliferation. This study investigated the role of cyclinD1 in the development of PH in broilers, and which bioactivators and signalling pathway are involved in the pathological process. The PH group contained 3-4-week-old broilers with clinical PH, and the healthy group broilers from the same flock without PH. Histopathology indicated pulmonary arterial walls were thicker in the PH group compared with the healthy group. Target gene expressions of macrophage migration inhibitory factor (MIF), extracellular signal-regulated kinase (ERK), and cyclinD1 detected by quantitative real-time PCR were upregulated in the PH group compared with the healthy group. Immunohistochemistry showed MIF, phosphorylated ERK (p-ERK) and cyclinD1 were present on pulmonary vascular walls; MIF was present in the cytoplasm of arterial endothelial cells and smooth muscle cells; p-ERK and cyclinD1 were present in smooth muscle cell cytoplasm. Western blotting demonstrated that MIF, p-ERKand cyclinD1 levels were significantly higher (P < 0.01) in the PH group compared with the healthy group. In summary, increased MIF in PH broiler pulmonary arteries upregulated cyclinD1 via the ERK signalling pathway to induce pulmonary vascular smooth muscle cell proliferation, causing pulmonary artery remodelling and hypertension.

  6. Clinical significance of the phosphorylation of MAPK and protein expression of cyclin D1 in human osteosarcoma tissues.

    PubMed

    Wu, Jian; Cui, Lei-Lei; Yuan, Jun; Wang, Yuan; Song, Shu

    2017-04-01

    The aim of the present study was to investigate the significance of the phosphorylation of mitogen-activated protein kinase (MAPK) and the protein expression of cyclin D1 in human osteosarcoma tissues. Human osteosarcoma tissue samples were collected from 30 patients, benign bone tumor samples were collected from 30 patients, and normal bone tissues were collected from 10 individuals as controls. Immunohistochemistry was performed to measure the levels of phosphorylated (p)-MAPK and cyclin D1 protein in cases of human osteosarcoma. The results showed that the positive rates of MAPK and cyclin D1 in osteosarcoma were 86.67% (26/30) and 73.00% (22/30), respectively. The positive staining rates of MAPK and cyclin D1 in benign bone tumor tissues were 10.00% (3/30) and 3.30% (1/30), respectively. The positive rate in the normal bone tissues was 0% (0/30), which was significantly lower, compared with that of the cancerous bone tissue. The positive rates of MAPK and cyclin D1 in osteosarcoma were increased (P<0.05), and the expression of cyclin D1 and p‑MAPK were positively correlated. The phosphorylation of MAPK may be important in the development of osteosarcoma, and the overactivation of MAPK may induce high expression of cyclin D1 and induce tumor cells to proliferate continuously.

  7. The checkpoint kinase ATM protects against stress-induced elevation of cyclin D1 and potential cell death in neurons.

    PubMed

    Hitomi, Masahiro; Stacey, Dennis W

    2010-06-01

    Quantitative cytometric studies show that cyclin D1 levels must decline during S phase for proper cell cycle progression, and that cyclin D1 decline follows phosphorylation induced by the checkpoint kinases ataxia telangiectasia mutated (ATM) and ATM and Rad3-related (ATR). ATM is mutated in ataxia telangiectasia (AT), a disease characterized by progressive neurodegeneration. Importantly, neurodegeneration in many cases has been linked to the increased expression of cyclin D1 in neurons leading to inappropriate cell cycle entry. These facts prompted us to test the possibility that ATM normally protects against neural degeneration by suppressing cyclin D1 levels, particularly following genotoxic stress. For this purpose, neural stem cells were induced to differentiate into mature neural cells, including neurons. ATM activity in these cultures was inhibited with a specific chemical inhibitor in the presence or absence of hydrogen peroxide treatment, and the effect on cyclin D1 expression was determined by quantitative, single cell cytometric analyses. As predicted, inhibition of ATM did promote elevation of cyclin D1 in differentiated neurons, particularly under conditions of oxidative stress. The survival of differentiated neurons and of neural stem cells was reduced by such treatments. These data support our suggestion that ATM functions to maintain low levels of cyclin D1 expression in differentiated neurons; and may provide important clues in understanding neural degeneration in general. Copyright 2010 International Society for Advancement of Cytometry.

  8. Correlation of cyclin D1 expression with aggressive DNA pattern in patients with tobacco-related intraoral squamous cell carcinoma

    PubMed Central

    Das, Satya N.; Khare, Pratima; Singh, Manoj K; Sharma, Suresh C.

    2011-01-01

    Background & objectives: Cyclin D1 has been strongly implicated in cell proliferation particularly in the G1/S checkpoint of the cell cycle, and prognoses in human malignancies. We investigated the correlation between cyclin D1 overexpression and clinicopathological features as well as cell cycle parameters to understand its clinical significance in patients with tobacco-related oral squamous cell carcinoma (OSCC). Methods: Immunohistochemistry for cyclin D1 and DNA flowcytometry for cell cycle parameters was done on paraffin embedded tumour samples from 45 patients with OSCC Results: Higher expression of cyclin D1 was observed only in 30 (66.6%) of 45 cases that correlated with advanced age (P <0.02), higher tumour stage ((P<0.01), histological differentiation and lymph node metastasis (P <0.01). Analysis of nuclear DNA pattern revealed cyclin D1 immunoreactivity in tumours with aggressive DNA pattern such as aneuploidy ((P<0.05) and higher S phase fraction ((P<0.04). Interpretation & conclusions: Higher expression of cyclin D1 in oral cancer appears to be closely linked to cell proliferation, differentiation and lymph node invasion. Pre-operative evaluation of cyclin D1 in biopsy specimen may be useful in planning the most appropriate treatment strategies in patients with tobacco-related OSCC. PMID:21537090

  9. The Rho GTPase effector ROCK regulates cyclin A, cyclin D1, and p27Kip1 levels by distinct mechanisms.

    PubMed

    Croft, Daniel R; Olson, Michael F

    2006-06-01

    The members of the Rho GTPase family are well known for their regulation of actin cytoskeletal structures. In addition, they influence progression through the cell cycle. The RhoA and RhoC proteins regulate numerous effector proteins, with a central and vital signaling role mediated by the ROCK I and ROCK II serine/threonine kinases. The requirement for ROCK function in the proliferation of numerous cell types has been revealed by studies utilizing ROCK-selective inhibitors such as Y-27632. However, the mechanisms by which ROCK signaling promotes cell cycle progression have not been thoroughly characterized. Using a conditionally activated ROCK-estrogen receptor fusion protein, we found that ROCK activation is sufficient to stimulate G1/S cell cycle progression in NIH 3T3 mouse fibroblasts. Further analysis revealed that ROCK acts via independent pathways to alter the levels of cell cycle regulatory proteins: cyclin D1 and p21(Cip1) elevation via Ras and the mitogen-activated protein kinase pathway, increased cyclin A via LIM kinase 2, and reduction of p27(Kip1) protein levels. Therefore, the influence of ROCK on cell cycle regulatory proteins occurs by multiple independent mechanisms.

  10. miR-340 inhibits glioblastoma cell proliferation by suppressing CDK6, cyclin-D1 and cyclin-D2

    SciTech Connect

    Li, Xuesong; Gong, Xuhai; Chen, Jing; Zhang, Jinghui; Sun, Jiahang; Guo, Mian

    2015-05-08

    Glioblastoma development is often associated with alteration in the activity and expression of cell cycle regulators, such as cyclin-dependent kinases (CKDs) and cyclins, resulting in aberrant cell proliferation. Recent studies have highlighted the pivotal roles of miRNAs in controlling the development and growth of glioblastoma. Here, we provide evidence for a function of miR-340 in the inhibition of glioblastoma cell proliferation. We found that miR-340 is downregulated in human glioblastoma tissue samples and several established glioblastoma cell lines. Proliferation and neurosphere formation assays revealed that miR-340 plays an oncosuppressive role in glioblastoma, and that its ectopic expression causes significant defect in glioblastoma cell growth. Further, using bioinformatics, luciferase assay and western blot, we found that miR-340 specifically targets the 3′UTRs of CDK6, cyclin-D1 and cyclin-D2, leading to the arrest of glioblastoma cells in the G0/G1 cell cycle phase. Confirming these results, we found that re-introducing CDK6, cyclin-D1 or cyclin-D2 expression partially, but significantly, rescues cells from the suppression of cell proliferation and cell cycle arrest mediated by miR-340. Collectively, our results demonstrate that miR-340 plays a tumor-suppressive role in glioblastoma and may be useful as a diagnostic biomarker and/or a therapeutic avenue for glioblastoma. - Highlights: • miR-340 is downregulated in glioblastoma samples and cell lines. • miR-340 inhibits glioblastoma cell proliferation. • miR-340 directly targets CDK6, cyclin-D1, and cyclin-D2. • miR-340 regulates glioblastoma cell proliferation via CDK6, cyclin-D1 and cyclin-D2.

  11. Functional, chemical genomic, and super-enhancer screening identify sensitivity to cyclin D1/CDK4 pathway inhibition in Ewing sarcoma

    PubMed Central

    Crompton, Brian; Cowley, Glenn; Vazquez, Francisca; Weir, Barbara A.; Tsherniak, Aviad; Parasuraman, Sudha; Kim, Sunkyu; Alexe, Gabriela; Stegmaier, Kimberly

    2015-01-01

    Ewing sarcoma is an aggressive bone and soft tissue tumor in children and adolescents, with treatment remaining a clinical challenge. This disease is mediated by somatic chromosomal translocations of the EWS gene and a gene encoding an ETS transcription factor, most commonly, FLI1. While direct targeting of aberrant transcription factors remains a pharmacological challenge, identification of dependencies incurred by EWS/FLI1 expression would offer a new therapeutic avenue. We used a combination of super-enhancer profiling, near-whole genome shRNA-based and small-molecule screening to identify cyclin D1 and CDK4 as Ewing sarcoma-selective dependencies. We revealed that super-enhancers mark Ewing sarcoma specific expression signatures and EWS/FLI1 target genes in human Ewing sarcoma cell lines. Particularly, a super-enhancer regulates cyclin D1 and promotes its expression in Ewing sarcoma. We demonstrated that Ewing sarcoma cells require CDK4 and cyclin D1 for survival and anchorage-independent growth. Additionally, pharmacologic inhibition of CDK4 with selective CDK4/6 inhibitors led to cytostasis and cell death of Ewing sarcoma cell lines in vitro and growth delay in an in vivo Ewing sarcoma xenograft model. These results demonstrated a dependency in Ewing sarcoma on CDK4 and cyclin D1 and support exploration of CDK4/6 inhibitors as a therapeutic approach for patients with this disease. PMID:26337082

  12. Hairy cell leukemia with translocation (11;20)(q13;q11) and overexpression of cyclin D1.

    PubMed

    Ishida, F; Kitano, K; Ichikawa, N; Ito, T; Kohara, Y; Taniguchi, T; Motokura, T; Kiyosawa, K

    1999-08-01

    We report on a male Japanese patient with hairy cell leukemia (HCL). A cytogenetic study with lipopolysaccharide stimuli showed a novel translocation (11;20)(q13;q11) in 10% of the analyzed cells. Northern blot analysis and RT-PCR analysis for cyclin D1 revealed the overexpression of cyclin D1, although the southern blot analysis of PRAD1 gene showed no rearrangement. In this particular case, the t(11;20)(q13;q11) might play some role in the oncogenesis of HCL and the overexpression of cyclin D1.

  13. Activation of cyclin D1 by estradiol and spermine in MCF-7 breast cancer cells: a mechanism involving the p38 MAP kinase and phosphorylation of ATF-2.

    PubMed

    Lewis, Joan S; Vijayanathan, Veena; Thomas, T J; Pestell, Richard G; Albanese, Chris; Gallo, Michael A; Thomas, Thresia

    2005-01-01

    Estradiol (E2) and the naturally occurring polyamines (putrescine, spermidine, and spermine) play important roles in breast cancer cell growth and differentiation. We examined the effects of E2 and spermine on the phosphorylation and DNA binding of activating transcription factor-2 (ATF-2) in MCF-7 breast cancer cells. ATF-2 is a transcription factor involved in estrogenic regulation of cyclin D1 gene, and thereby cell cycle progression. DNA affinity immunoblot assays showed a six- to eightfold increase in the binding of ATF-2 to a 74-mer ATF/CRE oligonucleotide (ODN1) from cyclin D1 promoter in the presence of 4 nM E2 and 0.5 mM spermine, compared to untreated control. Individual treatments with E2 or spermine caused a twofold or lower increase in ATF-2 binding to ODN1. Immunoblotting with phospho-ATF-2 antibody showed that increased DNA binding of ATF-2 was associated with its phosphorylation. A p38 MAP kinase inhibitor, PD169316, inhibited ATF-2 phosphorylation. In contrast, the MEK-ERK1/2 inhibitor, PD98059, or the JNK inhibitor, SP600125, had no significant effect on DNA binding of ATF-2. Cyclin D1 promoter (-1745CD1) activity increased by approximately 12-fold (above control) in the presence of E2 and spermine, compared to a sixfold increase in the presence of E2 alone and a twofold increase with spermine. Cells transfected with a dominant negative mutant of ATF-2 showed decreased transactivation of cyclin D1 promoter in response to E2 and spermine. These results indicate that spermine can enhance E2-induced cell signaling and cyclin D1 transcription by activation of the p38 MAP kinase and phosphorylation of ATF-2, contributing to breast cancer cell proliferation.

  14. Modulation of p53, c-fos, RARE, cyclin A, and cyclin D1 expression in human leukemia (HL-60) cells exposed to arsenic trioxide

    PubMed Central

    Yedjou, Clement G.; Tchounwou, Paul B.

    2010-01-01

    Arsenic trioxide (As2O3) has recently been successfully used to treat all-trans retinoic acid (ATRA) resistant relapsing acute promyelocytic leukemia. However, its molecular mechanisms of action are poorly understood. In the present study, we used the human leukemia (HL-60) cell line as a test model to study the cellular and molecular mechanisms of anti-cancer properties of As2O3. We hypothesized that As2O3-induced expression of stress genes and related proteins may play a role in the cellular and molecular events leading to cell cycle modulation in leukemic cells. To test this hypothesis, we performed Western blot analysis to assess the expression of specific cellular response proteins including p53, c-fos, RARE, Cyclin A, and Cyclin D1. Densitometric analysis was performed to determine the relative abundance of these proteins. Western Blot and densitometric analyses demonstrated a strong dose-response relationship with regard to p53 and RARE expression within the dose range of 0-8μg/mL. Expression of c-fos was slightly up-regulated at 2μg/mL, and down-regulated within the dose-range of 4-8 μg/mL. A statistically significant down-regulation of this protein was detected at the 6 and 8 μg/mL dose levels. No statistically significant differences (p>0.05) in Cyclin D1 expression was found between As2O3-treated cells and the control. Cyclin A expression in As2O3-treated HL-60 cells was up-regulated at 6μg/mL, suggesting that it is required for S phase and passage through G2 phase in cell cycle progression. Taken together, these results indicate that As2O3 has the potential to induce cell cycle arrest through activation of the 53-kDa tumor suppressor protein and repression of the c-fos transcription factor. Up-regulation of RARE by As2O3 indicates that its cytotoxicity may be mediated through interaction/binding with the retinoic acid receptor, and subsequent inhibition of growth and differentiation. PMID:19444595

  15. Effects of basic fibroblast growth factor and cyclin D1 on cigarette smoke-induced pulmonary vascular remodeling in rats.

    PubMed

    Zhou, Sijing; Li, Min; Zeng, Daxiong; Sun, Gengyun; Zhou, Junsheng; Wang, Ran

    2015-01-01

    Cigarette smoking may contribute to pulmonary hypertension in chronic obstructive pulmonary disease by resulting in pulmonary vascular remodeling that involves pulmonary artery smooth muscle cell proliferation. This study investigated the effects of basic fibroblast growth factor (bFGF) and cyclin D1 on the pulmonary vascular remodeling in smoking-exposed rats. Twenty-four male Wistar rats were randomly divided into four groups. Three tobacco-exposed groups were exposed to the smoke produced by 20 cigarettes for 60 min, twice a day for two, four or eight weeks, and the control group were exposed to fresh air. The expression of bFGF and cyclin D1 in the pulmonary arterial smooth muscle cells were determined using immunohistochemistry. Quantitative polymerase chain reaction was conducted to determine the expression levels of bFGF and cyclin D1 mRNA. In addition, the expression of bFGF and cyclin D1 proteins was evaluated by western blotting. The expression of bFGF and cyclin D1 at the mRNA and protein levels was shown to increase with the duration of smoke exposure (P<0.05). The correlation analysis indicated the expression of bFGF and cyclin D1 was positively associated with the pulmonary vessel wall thickness. The expression of bFGF was positively associated with that of cyclin D1. Collectively, the data demonstrated that the upregulation of bFGF and cyclin D1 occurred in rats subjected to smoke exposure, which may be associated with the abnormal proliferation of the smooth muscle cells in the pulmonary arteries.

  16. RhoA promotes epidermal stem cell proliferation via PKN1-cyclin D1 signaling

    PubMed Central

    Wang, Fan; Zhan, Rixing; Chen, Liang; Dai, Xia; Wang, Wenping; Guo, Rui; Li, Xiaoge; Li, Zhe; Wang, Liang; Huang, Shupeng; Shen, Jie

    2017-01-01

    Objective Epidermal stem cells (ESCs) play a critical role in wound healing, but the mechanism underlying ESC proliferation is not well defined. Here, we explore the effects of RhoA on ESC proliferation and the possible underlying mechanism. Methods Human ESCs were enriched by rapid adhesion to collagen IV. RhoA(+/+)(G14V), RhoA(-/-)(T19N) and pGFP control plasmids were transfected into human ESCs. The effect of RhoA on cell proliferation was detected by cell proliferation and DNA synthesis assays. Induction of PKN1 activity by RhoA was determined by immunoblot analysis, and the effects of PKN1 on RhoA in terms of inducing cell proliferation and cyclin D1 expression were detected using specific siRNA targeting PKN1. The effects of U-46619 (a RhoA agonist) and C3 transferase (a RhoA antagonist) on ESC proliferation were observed in vivo. Results RhoA had a positive effect on ESC proliferation, and PKN1 activity was up-regulated by the active RhoA mutant (G14V) and suppressed by RhoA T19N. Moreover, the ability of RhoA to promote ESC proliferation and DNA synthesis was interrupted by PKN1 siRNA. Additionally, cyclin D1 protein and mRNA expression levels were up-regulated by RhoA G14V, and these effects were inhibited by siRNA-mediated knock-down of PKN1. RhoA also promoted ESC proliferation via PKN in vivo. Conclusion This study shows that the effect of RhoA on ESC proliferation is mediated by activation of the PKN1-cyclin D1 pathway in vitro, suggesting that RhoA may serve as a new therapeutic target for wound healing. PMID:28222172

  17. Detection of cyclin D1 mRNA by hybridization sensitive NIC-oligonucleotide probe.

    PubMed

    Kovaliov, Marina; Segal, Meirav; Kafri, Pinhas; Yavin, Eylon; Shav-Tal, Yaron; Fischer, Bilha

    2014-05-01

    A large group of fluorescent hybridization probes, includes intercalating dyes for example thiazole orange (TO). Usually TO is coupled to nucleic acids post-synthetically which severely limits its use. Here, we have developed a phosphoramidite monomer, 10, and prepared a 2'-OMe-RNA probe, labeled with 5-(trans-N-hexen-1-yl-)-TO-2'-deoxy-uridine nucleoside, dU(TO), (Nucleoside bearing an Inter-Calating moiety, NIC), for selective mRNA detection. We investigated a series of 15-mer 2'-OMe-RNA probes, targeting the cyclin D1 mRNA, containing one or several dU(TO) at various positions. dU(TO)-2'-OMe-RNA exhibited up to 7-fold enhancement of TO emission intensity upon hybridization with the complementary RNA versus that of the oligomer alone. This NIC-probe was applied for the specific detection of a very small amount of a breast cancer marker, cyclin D1 mRNA, in total RNA extract from cancerous cells (250 ng/μl). Furthermore, this NIC-probe was found to be superior to our related NIF (Nucleoside with Intrinsic Fluorescence)-probe which could detect cyclin D1 mRNA target only at high concentrations (1840 ng/μl). Additionally, dU(T) can be used as a monomer in solid-phase oligonucleotide synthesis, thus avoiding the need for post-synthetic modification of oligonucleotide probes. Hence, we propose dU(TO) oligonucleotides, as hybridization probes for the detection of specific RNA in homogeneous solutions and for the diagnosis of breast cancer. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Immunohistochemical Analysis of Cyclin D1 Shows Deregulated Expression in Multiple Myeloma with the t(11;14)

    PubMed Central

    Pruneri, Giancarlo; Fabris, Sonia; Baldini, Luca; Carboni, Nadia; Zagano, Savina; Colombi, Maria Angela; Ciceri, Gabriella; Lombardi, Luigia; Rocchi, Mariano; Buffa, Roberto; Maiolo, Anna Teresa; Neri, Antonino

    2000-01-01

    The t(11;14)(q13;q32) chromosomal translocation, the hallmark of mantle cell lymphoma (MCL), is recurrently found in multiple myelomas (MM) by means of conventional cytogenetics. Unlike MCL, recent molecular studies of MM-derived cell lines with t(11;14) have indicated that the breakpoints are highly dispersed over the 11q13 region; however, the fact that cyclin D1 is generally overexpressed in these cell lines suggests that this gene is the target of the translocation. To evaluate further the involvement of cyclin D1 in MM, we used immunohistochemistry and fluorescence in situ hybridization to investigate cyclin D1 expression and the presence of chromosome 11 abnormalities in a representative panel of 48 MM patients (40 at diagnosis and 8 at relapse). Cyclin D1 overexpression occurred in 12/48 (25%) of cases; combined immunohistochemistry and fluorescence in situ hybridization analyses in 39 patients showed cyclin D1 positivity in all of the cases (7/7) bearing the t(11;14), in two of the 13 cases with trisomy 11, and in one of the 19 cases with no apparent abnormalities of chromosome 11. Our data indicate that the t(11;14) translocation in MM leads to cyclin D1 overexpression and that immunohistochemical analysis may represent a reliable means of identifying this lesion in MM. PMID:10793062

  19. MiR-15b Targets Cyclin D1 to Regulate Proliferation and Apoptosis in Glioma Cells

    PubMed Central

    Sun, Guan; Shi, Lei; Yan, Shushan; Wan, Zhengqiang; Jiang, Nan; Fu, Linshan; Li, Min; Guo, Jun

    2014-01-01

    Aim. To investigate the role and mechanism of miR-15b in the proliferation and apoptosis of glioma. Methods. The miR-15b mimics were transfected into human glioma cells to upregulate the miR-15b expression. Cyclin D1 was determined by both western blotting analysis and luciferase reporter assay. Methylthiazol tetrazolium (MTT) and flow cytometry were employed to detect the cell proliferation, cell cycle, and apoptosis. Results. Overexpression of miR-15b inhibits proliferation by arrested cell cycle progression and induces apoptosis, possibly by directly targeting Cyclin D1. Both luciferase assay and bioinformatics search revealed a putative target site of miR-15b binding to the 3′-UTR of Cyclin D1. Moreover, expression of miR-15b in glioma tissues was found to be inversely correlated with Cyclin D1 expression. Enforced Cyclin D1 could abrogate the miR-15b-mediated cell cycle arrest and apoptosis. Conclusions. Our findings identified that miR-15b may function as a glioma suppressor by targeting the Cyclin D1, which may provide a novel therapeutic strategy for treatment of glioma. PMID:24995320

  20. Apoptosis signal-regulating kinase 1 and cyclin D1 compose a positive feedback loop contributing to tumor growth in gastric cancer

    PubMed Central

    Hayakawa, Yoku; Hirata, Yoshihiro; Nakagawa, Hayato; Sakamoto, Kei; Hikiba, Yohko; Kinoshita, Hiroto; Nakata, Wachiko; Takahashi, Ryota; Tateishi, Keisuke; Tada, Motohisa; Akanuma, Masao; Yoshida, Haruhiko; Takeda, Kohsuke; Ichijo, Hidenori; Omata, Masao; Maeda, Shin; Koike, Kazuhiko

    2011-01-01

    Mitogen-activated protein kinase (MAPK) pathways regulate multiple cellular functions and are highly active in many types of human cancers. Apoptosis signal-regulating kinase 1 (ASK1) is an upstream MAPK involved in apoptosis, inflammation, and carcinogenesis. This study investigated the role of ASK1 in the development of gastric cancer. In human gastric cancer specimens, we observed increased ASK1 expression, compared to nontumor epithelium. Using a chemically induced murine gastric tumorigenesis model, we observed increased tumor ASK1 expression, and ASK1 knockout mice had both fewer and smaller tumors than wild-type (WT) mice. ASK1 siRNA inhibited cell proliferation through the accumulation of cells in G1 phase of the cell cycle, and reduced cyclin D1 expression in gastric cancer cells, whereas these effects were uncommon in other cancer cells. ASK1 overexpression induced the transcription of cyclin D1, through AP-1 activation, and ASK1 levels were regulated by cyclin D1, via the Rb–E2F pathway. Exogenous ASK1 induced cyclin D1 expression, followed by elevated expression of endogenous ASK1. These results indicate an autoregulatory mechanism of ASK1 in the development of gastric cancer. Targeting this positive feedback loop, ASK1 may present a potential therapeutic target for the treatment of advanced gastric cancer. PMID:21187402

  1. Human RAD6 Promotes G1-S Transition and Cell Proliferation through Upregulation of Cyclin D1 Expression

    PubMed Central

    Biskup, Ewelina; Liu, Yan; Chen, Pei-Chao; Chang, Jian-Feng; Jiang, Wenjie; Jing, Yuanya; Chen, Youwei; Jin, Hui; Chen, Su

    2014-01-01

    Protein ubiquitinylation regulates protein stability and activity. RAD6, an E2 ubiquitin-conjugating enzyme, which that has been substantially biochemically characterized, functions in a number of biologically relevant pathways, including cell cycle progression. In this study, we show that RAD6 promotes the G1-S transition and cell proliferation by regulating the expression of cyclin D1 (CCND1) in human cells. Furthermore, our data indicate that RAD6 influences the transcription of CCND1 by increasing monoubiquitinylation of histone H2B and trimethylation of H3K4 in the CCND1 promoter region. Our study presents, for the first time, an evidence for the function of RAD6 in cell cycle progression and cell proliferation in human cells, raising the possibility that RAD6 could be a new target for molecular diagnosis and prognosis in cancer therapeutics. PMID:25409181

  2. GSK3β-dependent cyclin D1 and cyclin E1 degradation is indispensable for NVP-BEZ235 induced G0/G1 arrest in neuroblastoma cells.

    PubMed

    Liu, Shan-Ling; Liu, Zhen; Zhang, Li-Di; Zhu, Han-Qing; Guo, Jia-Hui; Zhao, Mei; Wu, Yingli; Liu, Feng; Gao, Feng-Hou

    2017-10-05

    Cyclin D1 and cyclin E1, as vital regulatory factors of G1-S phase cell cycle progression, are frequently constitutive expressed and associated with pathogenesis and tumorigenesis in most human cancers and they have been regarded as promising targets for cancer therapy. In this study, we established NVP-BEZ235, a potent dual kinase inhibitor, could induce neuroblastoma cells proliferation inhibition without apoptosis activation. Moreover, we showed NVP-BEZ235 could induce neuroblastoma cells arrested at G0/G1 phase accompanied with significant reduction of the cyclin D1 and E1 proteins in a dose dependent manner at nanomole concentration. Additionally we found that GSK3β was dephosphorylated and activated by NVP-BEZ235 and then triggered cyclin D1 and cyclin E1 degradation through ubiquitination proteasome pathway, based on the evidences that NVP-BEZ235 induced downregulation of cyclin D1 and cyclin E1 were obviously recovered by proteasome inhibitor and the blockade of GSK3β contributed to remarkable rescue of cyclin D1 and cyclin E1. Analogous results about its anti-proliferation effects and molecular mechanism were observed on neuroblastoma xenograft mouse model in vivo. Therefore, these results indicate that NVP-BEZ235-induced cyclin D1 and cyclin E1 degradation, which happened through activating GSK3β, and GSK3β-dependent down-regulation of cyclin D1 and cyclin E1 should be available for anticancer therapeutics.

  3. A cyclin-D1 interaction with BAX underlies its oncogenic role and potential as a therapeutic target in mantle cell lymphoma

    PubMed Central

    Beltran, Elena; Fresquet, Vicente; Martinez-Useros, Javier; Richter-Larrea, Jose A.; Sagardoy, Ainara; Sesma, Izaskun; Almada, Luciana L.; Montes-Moreno, Santiago; Siebert, Reiner; Gesk, Stefan; Calasanz, Maria J.; Malumbres, Raquel; Rieger, Melissa; Prosper, Felipe; Lossos, Izidore S.; Piris, Miguel Angel; Fernandez-Zapico, Martin E.; Martinez-Climent, Jose A.

    2011-01-01

    The chromosomal translocation t(11;14)(q13;q32) leading to cyclin-D1 overexpression plays an essential role in the development of mantle cell lymphoma (MCL), an aggressive tumor that remains incurable with current treatment strategies. Cyclin-D1 has been postulated as an effective therapeutic target, but the evaluation of this target has been hampered by our incomplete understanding of its oncogenic functions and by the lack of valid MCL murine models. To address these issues, we generated a cyclin-D1–driven mouse model in which cyclin-D1 expression can be regulated externally. These mice developed cyclin-D1–expressing lymphomas capable of recapitulating features of human MCL. We found that cyclin-D1 inactivation was not sufficient to induce lymphoma regression in vivo; however, using a combination of in vitro and in vivo assays, we identified a novel prosurvival cyclin-D1 function in MCL cells. Specifically, we found that cyclin-D1, besides increasing cell proliferation through deregulation of the cell cycle at the G1–S transition, sequestrates the proapoptotic protein BAX in the cytoplasm, thereby favoring BCL2’s antiapoptotic function. Accordingly, cyclin-D1 inhibition sensitized the lymphoma cells to apoptosis through BAX release. Thus, genetic or pharmacologic targeting of cyclin-D1 combined with a proapoptotic BH3 mimetic synergistically killed the cyclin-D1–expressing murine lymphomas, human MCL cell lines, and primary lymphoma cells. Our study identifies a role of cyclin-D1 in deregulating apoptosis in MCL cells, and highlights the potential benefit of simultaneously targeting cyclin-D1 and survival pathways in patients with MCL. This effective combination therapy also might be exploited in other cyclin-D1–expressing tumors. PMID:21746927

  4. DICER1 regulated let-7 expression levels in p53-induced cancer repression requires cyclin D1

    PubMed Central

    Sun, Xin; Tang, Shou-Ching; Xu, Chongwen; Wang, Chenguang; Qin, Sida; Du, Ning; Liu, Jian; Zhang, Yiwen; Li, Xiang; Luo, Gang; Zhou, Jie; Xu, Fei; Ren, Hong

    2015-01-01

    Let-7 miRNAs act as tumour suppressors by directly binding to the 3′UTRs of downstream gene products. The regulatory role of let-7 in downstream gene expression has gained much interest in the cancer research community, as it controls multiple biological functions and determines cell fates. For example, one target of the let-7 family is cyclin D1, which promotes G0/S cell cycle progression and oncogenesis, was correlated with endoribonuclease DICER1, another target of let-7. Down-regulated let-7 has been identified in many types of tumours, suggesting a feedback loop may exist between let-7 and cyclin D1. A potential player in the proposed feedback relationship is Dicer, a central regulator of miRNA expression through sequence-specific silencing. We first identified that DICER1 is the key downstream gene for cyclin D1-induced let-7 expression. In addition, we found that let-7 miRNAs expression decreased because of the p53-induced cell death response, with deregulated cyclin D1. Our results also showed that cyclin D1 is required for Nutlin-3 and TAX-induced let-7 expression in cancer repression and the cell death response. For the first time, we provide evidence that let-7 and cyclin D1 form a feedback loop in regulating therapy response of cancer cells and cancer stem cells, and importantly, that alteration of let-7 expression, mainly caused by cyclin D1, is a sensitive indicator for better chemotherapies response. PMID:25702703

  5. Activation of the EGFR/Akt/NF-κB/cyclinD1 survival signaling pathway in human cholesteatoma epithelium.

    PubMed

    Liu, Wei; Yin, Tuanfang; Ren, Jihao; Li, Lihua; Xiao, Zian; Chen, Xing; Xie, Dinghua

    2014-02-01

    Cholesteatoma is a benign keratinizing squamous epithelial lesion characterized by the hyper-proliferation of keratinocytes with abundant production of keratin debris in the middle ear. The epidermal growth factor receptor (EGFR)/Akt/nuclear factor-kappa B (NF-κB)/cyclinD1 signaling pathway is one of the most important pathways in regulating cell survival and proliferation. We hypothesized that the EGFR/Akt/NF-κB/cyclinD1 signaling pathway may be activated and involved in the cellular hyperplasia mechanism in acquired cholesteatoma epithelium. Immunohistochemical staining of phosphorylated EGFR (p-EGFR), phosphorylated Akt (p-Akt), activated NF-κB and cyclinD1 protein was performed in 40 cholesteatoma samples and 20 samples of normal external auditory canal (EAC) epithelium. Protein expression of p-EGFR, p-Akt, activated NF-κB and cyclinD1 in cholesteatoma epithelium was significantly increased when compared with normal EAC epithelium (p < 0.01). In cholesteatoma epithelium, a significant positive association was observed between p-EGFR and p-Akt expression and between the expressions of p-Akt and NF-κB, NF-κB and cyclinD1, respectively (p < 0.01). No significant relationships were observed between the levels of investigated proteins and the degree of bone destruction (p > 0.05). The increased protein expression of p-EGFR, p-Akt, NF-κB and cyclinD1 and their associations in cholesteatoma epithelium suggest that the EGFR/Akt/NF-κB/cyclinD1 survival signaling pathway is active and may be involved in the regulatory mechanisms of cellular hyperplasia in cholesteatoma epithelium.

  6. Arcyriaflavin a, a cyclin D1-cyclin-dependent kinase4 inhibitor, induces apoptosis and inhibits proliferation of human endometriotic stromal cells: a potential therapeutic agent in endometriosis.

    PubMed

    Hirakawa, Tomoko; Nasu, Kaei; Aoyagi, Yoko; Takebayashi, Kanetoshi; Narahara, Hisashi

    2017-07-18

    We previously showed that microRNA-503 (miR-503) transfection into endometriotic cyst stromal cells (ECSCs) induced cell cycle arrest at the G0/G1 phase by suppressing cyclin D1. This finding prompted us to evaluate the potential therapeutic effects of cyclin D1 inhibitors in endometriotic cells. This study aimed to determine whether arcyriaflavin A, a representative inhibitor of cyclin D1-cyclin-dependent kinase 4 (CDK4), is beneficial in the treatment of endometriosis. ECSCs were isolated from the ovarian endometriotic tissues of 32 women. The effects of arcyriaflavin A on cell viability and proliferation, vascular endothelial growth factor A expression, apoptosis, and cell cycle progression were evaluated using a modified methylthiazoletetrazolium assay, enzyme-linked immunosorbent assay (ELISA), Caspase-Glo® 3/7 assay, and flow cytometry. Arcyriaflavin A significantly inhibited cell viability, proliferation, and angiogenesis of ECSCs as assessed using the 5-bromo-2-deoxyuridine (BrdU) and methylthiazoletetrazolium bromide (MTT) assays, and vascular endothelial growth factor (VEGF) ELISA. Arcyriaflavin A induced apoptosis as shown in the Caspase-Glo® 3/7 assay and cell death detection ELISA whilethe cell cycle was arrested at the G0/G1 phase. The findings indicate that cyclin D1-CDK4 inhibitors may be promising candidates for the treatment of endometriosis. This is the first study to demonstrate the potential usefulness of arcyriaflavin A as a therapeutic agent for endometriosis. Further studies of the effects of cyclin D1-CDK4 inhibitors on endometriosis may provide useful information on pathogenesis and treatment.

  7. The impact of cyclin D1 mRNA isoforms, morphology and p53 in mantle cell lymphoma: p53 alterations and blastoid morphology are strong predictors of a high proliferation index.

    PubMed

    Slotta-Huspenina, Julia; Koch, Ina; de Leval, Laurence; Keller, Gisela; Klier, Margit; Bink, Karin; Kremer, Marcus; Raffeld, Mark; Fend, Falko; Quintanilla-Martinez, Leticia

    2012-09-01

    Mantle cell lymphoma is a clinically heterogeneous disease characterized by overexpression of cyclin D1 protein. Blastoid morphology, high proliferation, and secondary genetic aberrations are markers of aggressive behavior. Expression profiling of mantle cell lymphoma revealed that predominance of the 3'UTR-deficient, short cyclin D1 mRNA isoform was associated with high cyclin D1 levels, a high "proliferation signature" and poor prognosis. Sixty-two cases of mantle cell lymphoma were analyzed for cyclin D1 mRNA isoforms and total cyclin D1 levels by real-time reverse transcriptase polymerase chain reaction, and TP53 alterations were assessed by immunohistochemistry and molecular analysis. Results were correlated with proliferation index and clinical outcome. Predominance of the short cyclin D1 mRNA was found in 14 (23%) samples, including four with complete loss of the standard transcript. TP53 alterations were found in 15 (24%) cases. Predominance of 3'UTR-deficient mRNA was significantly associated with high cyclin D1 mRNA levels (P=0.009) and more commonly found in blastoid mantle cell lymphoma (5/11, P=0.060) and cases with a proliferation index of >20% (P=0.026). Both blastoid morphology (11/11, P<0.001) and TP53 alterations (15/15, P<0.001) were significantly correlated with a high proliferation index. A proliferation index of 10% was determined to be a significant threshold for survival in multivariate analysis (P=0.01). TP53 alterations are strongly associated with a high proliferation index and aggressive behavior in mantle cell lymphoma. Predominance of the 3'UTR-deficient transcript correlates with higher cyclin D1 levels and may be a secondary contributing factor to high proliferation, but failed to reach prognostic significance in this study.

  8. The impact of cyclin D1 mRNA isoforms, morphology and p53 in mantle cell lymphoma: p53 alterations and blastoid morphology are strong predictors of a high proliferation index

    PubMed Central

    Slotta-Huspenina, Julia; Koch, Ina; de Leval, Laurence; Keller, Gisela; Klier, Margit; Bink, Karin; Kremer, Marcus; Raffeld, Mark; Fend, Falko; Quintanilla-Martinez, Leticia

    2012-01-01

    Background Mantle cell lymphoma is a clinically heterogeneous disease characterized by overexpression of cyclin D1 protein. Blastoid morphology, high proliferation, and secondary genetic aberrations are markers of aggressive behavior. Expression profiling of mantle cell lymphoma revealed that predominance of the 3’UTR-deficient, short cyclin D1 mRNA isoform was associated with high cyclin D1 levels, a high “proliferation signature” and poor prognosis. Design and Methods Sixty-two cases of mantle cell lymphoma were analyzed for cyclin D1 mRNA isoforms and total cyclin D1 levels by real-time reverse transcriptase polymerase chain reaction, and TP53 alterations were assessed by immunohistochemistry and molecular analysis. Results were correlated with proliferation index and clinical outcome. Results Predominance of the short cyclin D1 mRNA was found in 14 (23%) samples, including four with complete loss of the standard transcript. TP53 alterations were found in 15 (24%) cases. Predominance of 3’UTR-deficient mRNA was significantly associated with high cyclin D1 mRNA levels (P=0.009) and more commonly found in blastoid mantle cell lymphoma (5/11, P=0.060) and cases with a proliferation index of >20% (P=0.026). Both blastoid morphology (11/11, P<0.001) and TP53 alterations (15/15, P<0.001) were significantly correlated with a high proliferation index. A proliferation index of 10% was determined to be a significant threshold for survival in multivariate analysis (P=0.01). Conclusions TP53 alterations are strongly associated with a high proliferation index and aggressive behavior in mantle cell lymphoma. Predominance of the 3’UTR-deficient transcript correlates with higher cyclin D1 levels and may be a secondary contributing factor to high proliferation, but failed to reach prognostic significance in this study. PMID:22315488

  9. αB-crystallin is mutant B-RAF regulated and contributes to cyclin D1 turnover in melanocytic cells

    PubMed Central

    Hu, Rong; Aplin, Andrew E.

    2010-01-01

    Summary The serine/threonine kinase, B-RAF, is frequently mutated in melanoma and is required for cell proliferation. Proteasomal turnover of cyclins and cyclin-dependent kinase inhibitors via E3 ubiquitin ligases regulates cell cycle progression. We previously showed that B-RAF regulates Cks1, a co-factor for the F-box protein Skp2. Recently, a second F-box protein cofactor was identified, αB-crystallin, that binds Fbx4 and promotes cyclin D1 degradation. Here, we demonstrate that αB-crystallin is down-regulated in mutant B-RAF melanoma cells compared to melanocytes in a B-RAF and MEK-dependent manner. In a subset of lines, MEK inhibition was sufficient to up-regulate αB-crystallin protein levels; whereas in other lines combined MEK and proteasome inhibition was required. αB-crystallin knockdown partially stabilized cyclin D1 in melanocytes. Expression of αB-crystallin in mutant B-RAF melanoma cells did not promote cyclin D1 turnover under normal conditions, but did enhance turnover following etoposide-induced DNA damage. Together, these data show that αB-crystallin is highly expressed in melanocytes contributing, in part, to cyclin D1 turnover. Furthermore, αB-crystallin is down-regulated in a B-RAF-dependent manner in melanoma cells and its re-expression regulates cyclin D1 turnover after DNA damage. Significance αB-crystallin has been implicated in cellular functions as a heat shock protein and, more recently, as a cofactor for an E3 ligase ubiquitin ligase complex that degrades the cell cycle protein, cyclin D1. In this study we identify αB-crystallin as a target of aberrant B-RAF-MEK signaling that is hyper-activated in the majority of melanomas through mutation of B-RAF. Furthermore, we provide evidence for a functional role of αB-crystallin in contributing to the turnover of cyclin D1 in melanocytes and in melanoma cells following DNA damage inducing signals. These findings further our understanding of the regulation of cyclin D1 in melanocytic

  10. Tylophorine Analog DCB-3503 Inhibited Cyclin D1 Translation through Allosteric Regulation of Heat Shock Cognate Protein 70

    PubMed Central

    Wang, Ying; Lam, Wing; Chen, Shao-Ru; Guan, Fu-Lan; Dutchman, Ginger E.; Francis, Samson; Baker, David C.; Cheng, Yung-Chi

    2016-01-01

    Tylophorine analog DCB-3503 is a potential anticancer and immunosuppressive agent that suppresses the translation of cellular regulatory proteins, including cyclin D1, at the elongation step. However, the molecular mechanism underlying this phenomenon remains unknown. This study demonstrates that DCB-3503 preferentially binds to heat shock cognate protein 70 (HSC70), which is a determinant for cyclin D1 translation by binding to the 3′-untranslated region (3′ UTR) of its mRNA. DCB-3503 allosterically regulates the ATPase and chaperone activities of HSC70 by promoting ATP hydrolysis in the presence of specific RNA binding motifs (AUUUA) of cyclin D1 mRNA. The suppression of cyclin D1 translation by DCB-3503 is not solely caused by perturbation of the homeostasis of microRNAs, although the microRNA processing complex is dissociated with DCB-3503 treatment. This study highlights a novel regulatory mechanism of protein translation with AUUUA motifs in the 3′ UTR of mRNA by HSC70, and its activity can be allosterically modulated by DCB-3503. DCB-3503 may be used to treat malignancies, such as hepatocellular carcinoma or breast cancer with elevated expression of cyclin D1. PMID:27596272

  11. Cyclin D1 depletion induces DNA damage in mantle cell lymphoma lines.

    PubMed

    Mohanty, Suchismita; Mohanty, Atish; Sandoval, Natalie; Tran, Thai; Bedell, Victoria; Wu, Jun; Scuto, Anna; Murata-Collins, Joyce; Weisenburger, Dennis D; Ngo, Vu N

    2017-03-01

    Elevated cyclin D1 (CCND1) expression levels in mantle cell lymphoma (MCL) are associated with aggressive clinical manifestations related to chemoresistance, but little is known about how this important proto-oncogene contributes to the resistance of MCL. Here, we showed that RNA interference-mediated depletion of CCND1 increased caspase-3 activities and induced apoptosis in the human MCL lines UPN-1 and JEKO-1. In vitro and xenotransplant studies revealed that the toxic effect of CCND1 depletion in MCL cells was likely due to increase in histone H2AX phosphorylation, a DNA damage marker. DNA fiber analysis suggested deregulated replication initiation after CCND1 depletion as a potential cause of DNA damage. Finally, in contrast to depletion or inhibition of cyclin-dependent kinase 4, CCND1 depletion increased chemosensitivity of MCL cells to replication inhibitors hydroxyurea and cytarabine. Our findings have an important implication for CCND1 as a potential therapeutic target in MCL patients who are refractory to standard chemotherapy.

  12. Oncogene abnormalities in a series of primary melanomas of the sinonasal tract: NRAS mutations and cyclin D1 amplification are more frequent than KIT or BRAF mutations.

    PubMed

    Chraybi, Meriem; Abd Alsamad, Issam; Copie-Bergman, Christiane; Baia, Maryse; André, Jocelyne; Dumaz, Nicolas; Ortonne, Nicolas

    2013-09-01

    Primary malignant melanoma of sinonasal tract is a rare but severe form of melanoma. We retrospectively analyzed 17 cases and focused on the histologic presentation and the expression of c-Kit, epidermal growth factor receptor (EGFR), cyclin D1/Bcl-1, PS100, and HMB45 and searched for BRAF, NRAS, and KIT mutations that are known to be associated with melanoma subtypes, together with amplifications of KIT, cyclin D1, cyclin-dependent kinase 4, MDM2, and microphthalmia-associated transcription factor using quantitative polymerase chain reaction. In most cases (78%), an in situ component was evidenced. Invasive components were composed of diffuse areas of rhabdoid, epithelioid, or spindle cells and, in most cases, lacked inflammatory reaction, suggesting that an immune escape phenomenon probably develops when the disease progresses. EGFR was rarely and weakly expressed in the in situ component of 2 cases. None of the investigated case showed BRAF V600E, but 1 had a D594G mutation. NRAS mutations in exon 2 (G12D or G12A) were found in 3 cases (18%), and a KIT mutation in exon 11 (L576P), in 1, whereas c-Kit was expressed at the protein level in half of the cases. Amplifications of cyclin D1 were evidenced in 5 cases, confirmed in 3 by fluorescence in situ hybridization, but this was not always correlated with protein expression, found in 8 patients (62.5%), 3 having no significant amplification. In conclusion, primary malignant melanoma of sinonasal tract is not associated with BRAF V600E mutations. Instead, NRAS or KIT mutations and cyclin D1 amplification can be found in a proportion of cases, suggesting that primary malignant melanoma of sinonasal tract is heterogeneous at the molecular level and should not be sensitive to therapeutic approaches aiming at BRAF.

  13. Hyper sensitive protein detection by Tandem-HTRF reveals Cyclin D1 dynamics in adult mouse

    PubMed Central

    Zampieri, Alexandre; Champagne, Julien; Auzemery, Baptiste; Fuentes, Ivanna; Maurel, Benjamin; Bienvenu, Frédéric

    2015-01-01

    We present here a novel method for the semi-quantitative detection of low abundance proteins in solution that is both fast and simple. It is based on Homogenous Time Resolved Förster Resonance Energy Transfer (HTRF), between a lanthanide labeled donor antibody and a d2 or XL665 labeled acceptor antibody that are both raised against different epitopes of the same target. This novel approach we termed “Tandem-HTRF”, can specifically reveal rare polypeptides from only a few microliters of cellular lysate within one hour in a 384-well plate format. Using this sensitive approach, we observed surprisingly that the core cell cycle regulator Cyclin D1 is sustained in fully developed adult organs and harbors an unexpected expression pattern affected by environmental challenge. Thus our method, Tandem-HTRF offers a promising way to investigate subtle variations in the dynamics of sparse proteins from limited biological material. PMID:26503526

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

    PubMed Central

    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

    2016-01-01

    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. PMID:28035994

  15. 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.

  16. 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

  17. Lysine 269 is essential for cyclin D1 ubiquitylation by the SCFFbx4/αB-crystallin ligase and subsequent proteasome-dependent degradation

    PubMed Central

    O., Barbash; E., Egan; L.L., Pontano; J., Kosak; Diehl, J. Alan

    2009-01-01

    Protein ubiquitylation is a complex enzymatic process that results in the covalent attachment of ubiquitin, via Gly-76 of ubiquitin, to an ε-NH2-group of an internal lysine residue in a given substrate. While E3 ligases frequently utilize lysines adjacent to the degron within the substrate, many substrates can be targeted to the proteasome via polyubiquitylation of any lysine. We have assessed the role of lysine residues proximal to the cyclin D1 phosphodegron for ubiquitylation by the SCFFbx4/αB-crystallin ubiquitin ligase and subsequent proteasome-dependent degradation of cyclin D1. The work described herein reveals a requisite role for Lys-269 (K269) for the rapid, poly-ubiquitin mediated degradation of cyclin D1. Mutation of lysine 269, which is proximal to the phosphodegron sequence surrounding Thr-286 in cyclin D1, not only stabilizes cyclin D1, but also triggers cyclin D1 accumulation within the nucleus thereby promoting cell transformation. In addition, D1-K269R is resistant to genotoxic stress induced degradation, similar to non-phosphorylatable D1-T286A, supporting the critical role for the post-translational regulation of cyclin D1 in the response to DNA damaging agents. Strikingly, while mutation of lysine 269 to arginine inhibits cyclin D1 degradation, it does not inhibit cyclin D1 ubiquitylation in vivo demonstrating that ubiquitylation of a specific lysine can influence substrate targeting to the 26S proteasome. PMID:19767775

  18. Misexpression of cyclin D1 in embryonic germ cells promotes testicular teratoma initiation.

    PubMed

    Lanza, Denise G; Dawson, Emily P; Rao, Priya; Heaney, Jason D

    2016-01-01

    Testicular teratomas result from anomalies in embryonic germ cell development. In the 129 family of inbred mouse strains, teratomas arise during the same developmental period that male germ cells normally enter G1/G0 mitotic arrest and female germ cells initiate meiosis (the mitotic:meiotic switch). Dysregulation of this switch associates with teratoma susceptibility and involves three germ cell developmental abnormalities seemingly critical for tumor initiation: delayed G1/G0 mitotic arrest, retention of pluripotency, and misexpression of genes normally restricted to embryonic female and adult male germ cells. One misexpressed gene, cyclin D1 (Ccnd1), is a known regulator of cell cycle progression and an oncogene in many tissues. Here, we investigated whether Ccnd1 misexpression in embryonic germ cells is a determinant of teratoma susceptibility in mice. We found that CCND1 localizes to teratoma-susceptible germ cells that fail to enter G1/G0 arrest during the mitotic:meiotic switch and is the only D-type cyclin misexpressed during this critical developmental time frame. We discovered that Ccnd1 deficiency in teratoma-susceptible mice significantly reduced teratoma incidence and suppressed the germ cell proliferation and pluripotency abnormalities associated with tumor initiation. Importantly, Ccnd1 expression was dispensable for somatic cell development and male germ cell specification and maturation in tumor-susceptible mice, implying that the mechanisms by which Ccnd1 deficiency reduced teratoma incidence were germ cell autonomous and specific to tumorigenesis. We conclude that misexpression of Ccnd1 in male germ cells is a key component of a larger pro-proliferative program that disrupts the mitotic:meiotic switch and predisposes 129 inbred mice to testicular teratocarcinogenesis.

  19. Circadian variation in expression of G1 phase cyclins D1 and E and cyclin-dependent kinase inhibitors p16 and p21 in human bowel mucosa

    PubMed Central

    Griniatsos, John; Michail, Othon P; Theocharis, Stamatios; Arvelakis, Antonios; Papaconstantinou, Ioannis; Felekouras, Evangelos; Pikoulis, Emmanouel; Karavokyros, Ioannis; Bakoyiannis, Chris; Marinos, George; Bramis, John; Michail, Panayiotis O

    2006-01-01

    AIM: To evaluate whether the cellular proliferation rate in the large bowel epithelial cells is characterized by circadian rhythm. METHODS: Between January 2003 and December 2004, twenty patients who were diagnosed as suffering from primary, resectable, non-metastatic adenocarcinoma of the lower rectum, infiltrating the sphincter mechanism, underwent abdominoperineal resection, total mesorectal excision and permanent left iliac colostomy. In formalin-fixed and paraffin-embedded biopsy specimens obtained from the colostomy mucosa every six hours (00:00, 06:00, 12:00, 18:00 and 24:00), we studied the expression of G1 phase cyclins (D1 and E) as well as the expression of the G1 phase cyclin-dependent kinase (CDK) inhibitors p16 and p21 as indicators of cell cycle progression in colonic epithelial cells using immunohistochemical methods. RESULTS: The expression of both cyclins showed a similar circadian fashion obtaining their lowest and highest values at 00:00 and 18:00, respectively (P< 0.001). A circadian rhythm in the expression of CDK inhibitor proteins p16 and p21 was also observed, with the lowest levels obtained at 12:00 and 18:00 (P< 0.001), respectively. When the complexes cyclins D1 - p21 and E - p21 were examined, the expression of the cyclins was adversely correlated to the p21 expression throughout the day. When the complexes the cyclins D1 - p16 and E - p16 were examined, high levels of p16 expression were correlated to low levels of cyclin expression at 00:00, 06:00 and 24:00. Meanwhile, the highest expression levels of both cyclins were correlated to high levels of p16 expression at 18:00. CONCLUSION: Colonic epithelial cells seem to enter the G1 phase of the cell cycle during afternoon (between 12:00 and 18:00) with the highest rates obtained at 18:00. From a clinical point of view, the present results suggest that G1-phase specific anticancer therapies in afternoon might maximize their anti-tumor effect while minimizing toxicity

  20. High Expression of Cyclin D1 and p21 in N-Nitroso-N-Methylurea-Induced Breast Cancer in Wistar Albino Female Rats

    PubMed Central

    Ashrafi, Mahboobeh; Bathaie, Seyedeh Zahra; Abroun, Saeid

    2012-01-01

    Objective: N-nitroso-N-methylurea (NMU) induces breast cancer in rodents, particularly in rats. This model of breast cancer is very similar to human breast cancer. As a continuation of our recent work, we investigated the expressions of cyclin D1 and p21 in NMU-induced breast cancer of Wistar Albino rats. Materials and Methods: In this experimental study, mammary carcinoma was induced in female Wistar Albino rats by a new protocol which included the intraperitoneal injection of NMU (50 mg/kg) at 50, 65, and 80 days of the animal’s age. The animals were weighed weekly and palpated in order to record the numbers, location, and size of tumors. Subsequently tumor incidence (TI), latency period (LP), and tumor multiplicity (TM) were reported. About four weeks after the tumor size reached 1.5 cm3, rats were sacrificed. Cyclin D1 and p21 expressions in tumors and normal mammary glands from normal rats were measured by reverse-transcription polymerase chain reaction (RT- PCR) and Western blot analysis. Statistical analysis of the data was performed using SPSS software version 16.0. Results: The efficiency of tumor induction was 65%, LP was 150 days, and a TM of 1.43 ± 0.53 per rat was noted. RT-PCR and Western blot data indicated significant (p<0.05) induction of both cyclin D1 and p21 expressions in rat mammary tumors compared with normal tissue from the control group. Conclusion: These results indicate an efficient mammary tumor induction protocol for this type of rat, which is accompanied by an increase in cyclin D1 and p21 expressions. PMID:23508728

  1. Frequent deletions and mutations of the beta-catenin gene are associated with overexpression of cyclin D1 and fibronectin and poorly differentiated histology in childhood hepatoblastoma.

    PubMed

    Takayasu, H; Horie, H; Hiyama, E; Matsunaga, T; Hayashi, Y; Watanabe, Y; Suita, S; Kaneko, M; Sasaki, F; Hashizume, K; Ozaki, T; Furuuchi, K; Tada, M; Ohnuma, N; Nakagawara, A

    2001-04-01

    Hepatoblastoma (HBL) is the most common malignant liver tumor in young children. Recent reports have shown that the beta-catenin gene was frequently mutated or deleted in HBLS: To elucidate the role of beta-catenin abnormalities in HBLs, we searched for mutations of beta-catenin and APC as well as expression of the target genes, cyclin D1, c-myc, and fibronectin, in 68 primary HBLS: The mutation analysis revealed that 44 (65%) tumors carried missense mutations or deletions of beta-catenin, all of which were somatic and targeted to the exon 3 encoding the amino acid residues involved in its degradation. However, no loss of function mutation of the APC gene was detected by the yeast functional assay. Of interest, beta-catenin mutation was significantly correlated with overexpression of the target genes, cyclin D1 and fibronectin, but not with that of c-myc in HBLs as measured by quantitative real-time reverse transcription-PCR. The immunohistochemical studies in 15 HBLs demonstrated that the nuclear/cytoplasmic accumulation of beta-catenin was positive in 13 tumors, 9 of which had the deletion or mutation of the gene. The significant correlation between the beta-catenin gene abnormality and the positive staining of cyclin D1 was also confirmed. Furthermore, the nuclear accumulation of beta-catenin was strongly associated with the poorly differentiated tumor cell components as well as with the positive staining of cyclin D1 within the tumor. Thus, our present results suggested that the gain of function mutation of beta-catenin played a crucial role in the malignant progression of HBL in vivo.

  2. Sphk1 promotes breast epithelial cell proliferation via NF-κB-p65-mediated cyclin D1 expression

    PubMed Central

    Li, Shifei; Zhou, Yan; Zheng, Xiaodong; Wu, Xiujuan; Liang, Yueyang; Wang, Shushu; Zhang, Yi

    2016-01-01

    Lipid metabolism is crucially involved with the promotion of malignant progression and metastasis in various cancers. Growing evidence suggests that many types of cancers express high levels of sphingosine kinase 1 (Sphk1), which is known to mediate cell proliferation We hypothesized that Sphk1/sphingosine-1-phosphate (S1P) signaling contributes to tumor progression. In MCF10A and MCF10A-Sphk1 breast epithelial cells, we used TNF-α to activate the Sphk1/S1P pathway and the measured expression levels of NF-κBp65 and cyclin D1 mRNA and protein in the presence and absence of an NF-κB-p65 inhibitor. Chromatin immunoprecipitation assays were performed to determine whether NF-κB-p65 binds to the cyclin D1 promoter. We found that overexpression of Sphk1 induced NF-κB-p65 activation, increased expression of cyclin D1, shortened the cell division cycle, and thus promoted proliferation of breast epithelial cells. These findings provide insight into the mechanism by which an Sphk1/NF-κB-p65/cyclin D1 signaling pathway mediates cell proliferation. PMID:27811358

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

    PubMed

    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.

  4. Eradication of Helicobacter pylori Infection Restores ki67, p53, and Cyclin D1 Immunoreactivity in the Human Gastric Epithelium

    PubMed Central

    Triantafyllou, Konstantinos; Papadopoulos, Vasilios; Emanouil, Theodoros; Gkolfakis, Paraskevas; Damaskou, Vasileia; Tziatzios, Georgios; Panayiotides, Ioannis G.; Vafiadis, Irene; Ladas, Spiros D.

    2016-01-01

    INTRODUCTION We evaluated the effect of Helicobacter pylori (HP) eradication on p53, cyclin D1 expression, and cell proliferation in gastric mucosa. MATERIALS AND METHODS We assessed p53, cyclin D1, and ki67 immunoexpression in gastric mucosa from 31 HP chronic gastritis patients and 12 controls. Reassessment was performed 6 months after successful HP eradication. RESULTS Successful eradication resulted in significant decrease of p53 (1.53 ± 0.16 vs 0.83 ± 0.19, P = 0.01) and ki67 (9.84 ± 0.96 vs 4.77 ± 0.27, P < 0.001) staining in the antrum. Similarly, p53 immunoreactivity significantly decreased in the corpus (1.27 ± 0.20 vs 0.46 ± 0.15, P = 0.02), while there was a trend for decreased corpus cyclin D1 and ki67 expression (0.17 ± 0.07 vs 0.0, P = 0.08 and 8.71 ± 1.24 vs 5.85 ± 0.54, P = 0.09, respectively). Importantly, after successful HP eradication, the immunoreactivity of the studied parameters was similar to that of controls. CONCLUSION Successful HP infection eradication restores p53, cyclin D1, and ki67 immunoreactivity in the gastric mucosa to the level of controls. PMID:27891056

  5. Effect of growth factors and steroid hormones on heme oxygenase and cyclin D1 expression in primary astroglial cell cultures.

    PubMed

    Bramanti, V; Grasso, S; Tomassoni, D; Traini, E; Raciti, G; Viola, M; Li Volti, G; Campisi, A; Amenta, F; Avola, R

    2015-03-01

    Astrocyte activity may be modulated by steroid hormones and GFs. This study investigates the interaction between glucocorticoids or estrogens and GFs on the expression of heme oxygenase-1 (HO-1) and cyclin D1 in astrocyte cultures at 14 days treated for 48 or 60 hr with dexamethasone (DEX) or 48 hr with 17β-estradiol (E2) alone or with GFs added only in the last 12 or 24 hr. Twelve- or twenty-four-hour epidermal growth factor (EGF) treatment significantly enhanced HO-1 expression in astrocyte cultures pretreated for 48 hr with DEX. A highly significant increase in HO-1 expression was obtained after the last-12-hr EGF treatment in 48-hr E2-pretreated astrocyte cultures; this enhancement was particularly significant in 48-hr E2-pretreated cultures as well as in the last-12-hr insulin-treated ones pretreated for 48 hr with E2. Sixty-hour DEX-alone pretreatment as well as the last-12-hr EGF treatment in 60-hr DEX-pretreated astrocyte cultures showed a significant increase of cyclin D1 expression. A significant decrease of cyclin D1 expression in the last-12-hr insulin-like growth factor-I (IGF-1)-treated cultures pretreated for 60 hr with DEX was observed. A highly significant enhancement in cyclin D1 expression in 14 days in vitro astrocyte cultures pretreated with E2 alone for 48 hr and treated in the last 12 hr with IGF-1 in 48-hr E2-pretreated cultures was found. Finally, the data highlight an interactive dialogue between the growth factors and glucocorticoids or estrogens during the maturation of astroglial cells in culture that may control the HO-1 and cyclin D1 expression as well as proliferating astroglial cells during the cell cycle.

  6. Amplification of EGFR and cyclin D1 genes associated with human papillomavirus infection in oral squamous cell carcinoma.

    PubMed

    Chuerduangphui, Jureeporn; Pientong, Chamsai; Patarapadungkit, Natcha; Chotiyano, Apinya; Vatanasapt, Patravoot; Kongyingyoes, Bunkerd; Promthet, Supannee; Swangphon, Piyawut; Bumrungthai, Sureewan; Pimson, Charinya; Ekalaksananan, Tipaya

    2017-09-01

    Human papillomavirus (HPV) infection is associated with several genetic alterations including oncogene amplification, leading to increased aggression of tumors. Recently, a relationship between HPV infection and oncogene amplification has been reported, but this finding remains controversial. This study therefore investigated relationships between HPV infection and amplification of genes in the epidermal growth factor receptor (EGFR) signaling cascade in oral squamous cell carcinoma (OSCC). Extracted DNA from 142 formalin-fixed paraffin-embedded (FFPE) OSCC tissues was performed to investigate the copy number of EGFR, KRAS, c-myc and cyclin D1 genes using real-time polymerase chain reaction (RT-PCR) and compared with calibrators. A tissue microarray of OSCC tissues was used for detection of c-Myc expression and HPV infection by immunohistochemistry and HPV E6/E7 RNA in situ hybridization, respectively. HPV infection was also investigated using PCR and RT-PCR. Of the 142 OSCC samples, 81 (57%) were HPV-infected cases. The most frequently amplified gene was c-myc (55.6%), followed by cyclin D1 (26.1%), EGFR (23.9%) and KRAS (19.7%). Amplification of c-myc was significantly associated with levels of its protein product. EGFR amplification was also significantly associated with amplification of genes in the signaling cascade: KRAS (50.0%), c-myc (34.2%) and cyclin D1 (46.0%). Interestingly, HPV infection was significantly associated with amplification of both EGFR (76.5%) and cyclin D1 (73.0%). Only cyclin D1 amplification was significantly associated with severity of OSCC histopathology. HPV infection may play an important synergistic role in amplification of genes in the EGFR signaling cascade, leading to increased aggression in oral malignancies.

  7. Expression of cyclin D1 in epithelial tissues of transgenic mice results in epidermal hyperproliferation and severe thymic hyperplasia.

    PubMed Central

    Robles, A I; Larcher, F; Whalin, R B; Murillas, R; Richie, E; Gimenez-Conti, I B; Jorcano, J L; Conti, C J

    1996-01-01

    To study the involvement of cyclin D1 in epithelial growth and differentiation and its putative role as an oncogene in skin, transgenic mice were developed carrying the human cyclin D1 gene driven by a bovine keratin 5 promoter. As expected, all squamous epithelia including skin, oral mucosa, trachea, vaginal epithelium, and the epithelial compartment of the thymus expressed aberrant levels of cyclin D1. The rate of epidermal proliferation increased dramatically in transgenic mice, which also showed basal cell hyperplasia. However, epidermal differentiation was unaffected, as shown by normal growth arrest of newborn primary keratinocytes in response to high extracellular calcium. Moreover, an unexpected phenotype was observed in the thymus. Transgenic mice developed a severe thymic hyperplasia that caused premature death due to cardio-respiratory failure within 4 months of age. By 14 weeks, the thymi of transgenic mice increased in weight up to 40-fold, representing 10% of total body weight. The hyperplastic thymi had normal histology revealing a well-differentiated cortex and medulla, which supported an apparently normal T-cell developmental program based on the distribution of thymocyte subsets. These results suggest that proliferation and differentiation of epithelial cells are under independent genetic controls in these organs and that cyclin D1 can modulate epithelial proliferation without altering the initiation of differentiation programs. No spontaneous development of epithelial tumors or thymic lymphomas was perceived in transgenic mice during their first 8 months of life, although they continue under observation. This model provides in vivo evidence of the action of cyclin D1 as a pure mediator of proliferation in epithelial cells. Images Fig. 1 Fig. 2 Fig. 3 PMID:8755527

  8. Cyclin D1 (Bcl-1, PRAD1) protein expression in low-grade B-cell lymphomas and reactive hyperplasia.

    PubMed Central

    Yang, W. I.; Zukerberg, L. R.; Motokura, T.; Arnold, A.; Harris, N. L.

    1994-01-01

    Mantle cell (centrocytic) lymphoma (MCL) and occasional cases of B-cell small lymphocytic lymphoma/chronic lymphocytic leukemia (B-SLL/CLL) show a characteristic translocation, t(11:14)(q13;q32) involving rearrangement of the Bcl-1 region. Recently it was shown that the key Bcl-1 region oncogene is cyclin D1/PRAD1; cyclin D1 mRNA was shown to be overexpressed in cases of MCL. We examined cyclin D1 protein expression in low-grade B-cell lymphomas and reactive lymphoid hyperplasias using polyclonal and monoclonal antibodies to cyclin D1 protein. Definite nuclear staining was seen in 15 of 15 MCLs, 1 of 7 B-SLL/CLLs, 0 of 7 reactive hyperplasias, 0 of 10 follicular lymphomas, and 0 of 4 lymphomas of mucosa-associated lymphoid tissue using immunoperoxidase stains on paraffin-embedded sections. Best results were obtained with the affinity-purified polyclonal antibody on microwave-treated, formalin-fixed, paraffin-embedded tissue. MCLs showed diffuse nuclear staining, whereas the one positive B-SLL/CLL showed dot-like or globular nuclear staining. Nuclear cyclin D1 protein can be detected in all cases of MCL and in rare cases of B-SLL/CLL using an immunohistochemical technique on formalin-fixed, paraffin-embedded tissue, and it does not appear to be detectable in reactive hyperplasias and other low-grade B-cell lymphomas. This protein may be useful in subclassification of low-grade B-cell lymphomas. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 PMID:7518196

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

    SciTech Connect

    Yoshihara, Takashi; Collado, Denise; Hamaguchi, Masaaki . E-mail: hamaguchi@fordham.edu

    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. 346 (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.

  10. Differential expression of cyclin D1 in keratin-producing odontogenic cysts.

    PubMed

    Vera-Sirera, Beatriz; Forner-Navarro, Leopoldo; Vera-Sempere, Francisco

    2015-01-01

    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. 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. 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. 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.

  11. p16( INK4a) positively regulates cyclin D1 and E2F1 through negative control of AUF1.

    PubMed

    Al-Khalaf, Huda H; Colak, Dilek; Al-Saif, Maher; Al-Bakheet, Albandary; Hendrayani, Siti-Faujiah; Al-Yousef, Nujoud; Kaya, Namik; Khabar, Khalid S; Aboussekhra, Abdelilah

    2011-01-01

    The cyclin-D/CDK4,6/p16(INK4a)/pRB/E2F pathway, a key regulator of the critical G1 to S phase transition of the cell cycle, is universally disrupted in human cancer. However, the precise function of the different members of this pathway and their functional interplay are still not well defined. We have shown here that the tumor suppressor p16(INK4a) protein positively controls the expression of cyclin D1 and E2F1 in both human and mouse cells. p16(INK4a) stabilizes the mRNAs of the corresponding genes through negative regulation of the mRNA decay-promoting AUF1 protein. Immunoprecipitation of AUF1-associated RNAs followed by RT-PCR indicated that endogenous AUF1 binds to the cyclin D1 and E2F1 mRNAs. Furthermore, AUF1 down-regulation increased the expression levels of these genes, while concurrent silencing of AUF1 and p16(INK4a), using specific siRNAs, restored normal expression of both cyclinD1 and E2F1. Besides, we have shown the presence of functional AU-rich elements in the E2F1 3'UTR, which contributed to p16/AUF1-mediated regulation of E2F1 post-transcriptional events in vivo. Importantly, genome-wide gene expression microarray analysis revealed the presence of a large number of genes differentially expressed in a p16(INK4a) -dependent manner, and several of these genes are also members of the AUF1 and E2F1 regulons. We also present evidence that E2F1 mediates p16-dependent regulation of several pro- and anti-apoptotic proteins, and the consequent induction of spontaneous as well as doxorubicin-induced apoptosis. These findings show that the cyclin-dependent kinase inhibitor p16( INK4a) is also a modulator of transcription and apoptosis through controlling the expression of two major transcription regulators, AUF1 and E2F1.

  12. p18Ink4cand p53 act as tumor suppressors in Cyclin D1-driven primitive neuroectodermal tumor

    PubMed Central

    Saab, Raya; Rodriguez-Galindo, Carlos; Matmati, Kelly; Rehg, Jerold E.; Baumer, Shannon H.; Khoury, Joseph D.; Billups, Catherine; Neale, Geoffrey; Helton, Kathleen J.; Skapek, Stephen X.

    2008-01-01

    The RB tumor suppressor pathway is likely important in primitive neuroectodermal tumors (PNET) of the brain. In fact, 10-15% of children born with RB mutations develop brain PNETs, commonly in the pineal gland. Cyclin D1, which in association with Cyclin-dependent kinases (Cdk) 4 and 6 phosphorylates and inactivates the RB protein, is expressed in 40% of sporadic medulloblastoma, a PNET of the cerebellum. To understand tumorigenic events cooperating with RB pathway disruption in brain PNET, we generated a transgenic mouse where Cyclin D1 was expressed in pineal cells. Cyclin D1 enhanced pinealocyte proliferation, causing pineal gland enlargement. However, proliferation ceased beyond 2 weeks of age with reversal of Cdk4-mediated Rb phosphorylation despite continued expression of the transgene, and the pineal cells showed heterochromatin foci suggestive of a senescent-like state. In the absence of the p53 tumor suppressor, cell proliferation continued, resulting in pineal PNET that limited mouse survival to ~ 4 months. Interestingly, the Cdk-inhibitor p18Ink4c was induced in the transgenic pineal glands independently of p53, and transgenic mice that lacked Ink4c developed invasive PNET, though at an older age than those lacking p53. Analogous to our mouse model, we found that children with heritable retinoblastoma often had asymptomatic pineal gland enlargement that only rarely progressed to PNET. Our finding that the Cdk4-inhibitor p18Ink4c is a tumor suppressor in Cyclin D1-driven PNET suggests that pharmacological interventions to inhibit Cdk4 activity may be a useful chemoprevention or therapeutic strategy in cancer driven by primary Rb pathway disruption. PMID:19147556

  13. Cyclin D1 G870A polymorphism: Association with uterine leiomyoma risk and in silico analysis

    PubMed Central

    Salimi, Saeedeh; Shahrakipour, Mahnaz; Hajizadeh, Azam; Mokhtari, Mojgan; Mousavi, Mahdieh; Teimoori, Batool; Yaghmaei, Minoo

    2017-01-01

    Uterine leiomyoma (UL) is the most common benign tumor causing considerable morbidity during the reproductive years in women. Cyclin D1 (CCND1) is a cell cycle regulatory protein that is required for the G1 phase, and increased expression levels of this protein may affect tumorigenesis. The present study aimed to assess the possible effect of the CCND1 G870A polymorphism on UL susceptibility. A total of 154 women with UL and 197 healthy women who were age-, body mass index (BMI)- and ethnicity-matched were genotyped for the CCND1 G870A (rs9344) polymorphism using the polymerase chain reaction-restriction fragment length polymorphism method. The effects of G870A transition on the structure of mRNA and proteins of CCND1 was evaluated using bioinformatics tools. The frequency of the CCND1 870AA genotype was significantly higher in women with UL compared with the control subjects, and the risk of UL was 1.4-fold higher in women with the AA genotype when compared with the GG genotype before and after adjusting for age, BMI, and ethnicity [odds ratio (OR), 1.4; 95% confidence interval (CI), 1.1–2 (P=0.02)]. The frequency of CCND1 870GA genotype was not significantly different between the two groups. The frequency of the CCND1 870A allele was significantly higher in the women with UL when compared with the control subjects (57 vs. 48%; P=0.02). The in silico analysis revealed that the G870A transition may fundamentally alter the structure of the CCND1-mRNA. Thus, the CCND1 870AA genotype was associated with UL susceptibility in a sample of women from the southeast of Iran. PMID:28357079

  14. MicroRNA-193b Represses Cell Proliferation and Regulates Cyclin D1 in Melanoma

    PubMed Central

    Chen, Jiamin; Feilotter, Harriet E.; Paré, Geneviève C.; Zhang, Xiao; Pemberton, Joshua G.W.; Garady, Cherif; Lai, Dulcie; Yang, Xiaolong; Tron, Victor A.

    2010-01-01

    Cutaneous melanoma is an aggressive form of human skin cancer characterized by high metastatic potential and poor prognosis. To better understand the role of microRNAs (miRNAs) in melanoma, the expression of 470 miRNAs was profiled in tissue samples from benign nevi and metastatic melanomas. We identified 31 miRNAs that were differentially expressed (13 up-regulated and 18 down-regulated) in metastatic melanomas relative to benign nevi. Notably, miR-193b was significantly down-regulated in the melanoma tissues examined. To understand the role of miR-193b in melanoma, functional studies were undertaken. Overexpression of miR-193b in melanoma cell lines repressed cell proliferation. Gene expression profiling identified 314 genes down-regulated by overexpression of miR-193b in Malme-3M cells. Eighteen of these down-regulated genes, including cyclin D1 (CCND1), were also identified as putative miR-193b targets by TargetScan. Overexpression of miR-193b in Malme-3M cells down-regulated CCND1 mRNA and protein by ≥50%. A luciferase reporter assay confirmed that miR-193b directly regulates CCND1 by binding to the 3′untranslated region of CCND1 mRNA. These studies indicate that miR-193b represses cell proliferation and regulates CCND1 expression and suggest that dysregulation of miR-193b may play an important role in melanoma development. PMID:20304954

  15. QKI-5 suppresses cyclin D1 expression and proliferation of oral squamous cell carcinoma cells via MAPK signalling pathway.

    PubMed

    Fu, X; Feng, Y

    2015-05-01

    Oral squamous cell carcinoma (OSCC) is one of the most frequently occurring malignancies in the world. The RNA-binding protein quaking (QKI) is a newly identified tumour suppressor in multiple cancers, but its role in OSCC is currently unknown. The purpose of the present study was to clarify the relationship between QKI expression and OSCC development. We found QKI-5 expression to be significantly decreased in the oral cancer cell line CAL-27. QKI-5 overexpression also reduced the proliferation of CAL-27 cells, which correlated with cyclin D1. This regulative function of QKI-5 occurs by modulating the phosphorylation level of the mitogen-activated protein kinase (MAPK) pathway. Therefore this study shows that underexpression of tumour suppressor QKI-5 could activate the MAPK pathway and contribute to uncontrolled cyclin D1 expression, thus resulting in increased proliferation of oral cancer cells.

  16. OVCA1 inhibits the proliferation of epithelial ovarian cancer cells by decreasing cyclin D1 and increasing p16.

    PubMed

    Kong, Fandou; Tong, Rui; Jia, Lingyu; Wei, Wei; Miao, Xiaoyan; Zhao, Xinyu; Sun, Wenping; Yang, Guang; Zhao, Chunyan

    2011-08-01

    OVCA1, a tumor suppressor gene, is deleted or lower expressed in about 80% of ovarian cancer. Over expression of OVCA1 in human ovarian cancer A2780 cells inhibits cell proliferation and arrests cells in G1 stage. However, the fact that the molecular mechanism of OVCA1 inhibits cell growth is presently elusive. Here we investigated the potential signaling pathway induced by over-expression of OVCA1. Our results show that over-expression of human OVCA1 in ovarian cancer cells A2780 leads to down-regulation of cyclin D1, and up-regulation of p16, but no effect on the expression of NF-κB. It indicates that OVCA1 could inhibit the proliferation of ovarian cancer cell A2780 by p16/cyclin D1 pathway, but not by NF-κB.

  17. Retinoblastoma and p16 proteins in mammary carcinoma: their relationship to cyclin D1 and histopathological parameters.

    PubMed

    Dublin, E A; Patel, N K; Gillett, C E; Smith, P; Peters, G; Barnes, D M

    1998-02-20

    The cell cycle-associated retinoblastoma protein (pRb) and p16 protein were demonstrated using immuno-histochemistry on paraffin sections from 192 cases of invasive breast carcinoma. Abnormal expression of pRb was defined as negative staining and was seen in 17% of tumours. Such abnormal expression was significantly more frequent in tumours with negative oestrogen receptor (ER) status. There was also a trend for tumours which were negative for pRb to be grade III ductal carcinomas. There was no association between p16 staining and any histopathological parameter, though, surprisingly, log-rank analysis showed that strong staining was associated with a poor outcome. There was a significant inverse relationship between pRb and p16 expression and a significant positive association between pRb and cyclin D1. In a Cox multivariate analysis, which included cyclin D1, neither pRb nor p16 was an independent predictor of patient outcome.

  18. Myostatin induces p300 degradation to silence cyclin D1 expression through the PI3K/PTEN/Akt pathway.

    PubMed

    Ji, Ming; Zhang, Qiang; Ye, Jianwei; Wang, Xueyan; Yang, Wei; Zhu, Dahai

    2008-08-01

    Myostatin is a negative regulator of skeletal muscle growth and affects numerous genes expression involved in cell proliferation, differentiation and metabolism. However, the molecular mechanisms underlying myostatin-regulated genes expression remain to be elucidated. In this study, we showed that myostatin blocked the recruitment of p300 to the cyclin D1 promoter, resulting in the silence of cyclin D1 expression. Our data further demonstrated that myostatin decreased the protein level of p300 by inducing p300 degradation via the ubiquitin-proteasome system. In addition, we provided experimental evidence to show that myostatin-induced p300 degradation was mediated by the phosphatidylinositol 3-kinase/PTEN/Akt signaling pathway and this could be antagonized by IGF-1 or insulin. Results presented in this study uncovered an epigenetic control of genes expression in response to myostatin.

  19. 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.

  20. CCND1 rearrangements and cyclin D1 overexpression in renal oncocytomas: frequency, clinicopathologic features, and utility in differentiation from chromophobe renal cell carcinoma.

    PubMed

    Sukov, William R; Ketterling, Rhett P; Lager, Donna J; Carlson, Austin W; Sinnwell, Jason P; Chow, George K; Jenkins, Robert B; Cheville, John C

    2009-09-01

    Renal oncocytoma is a benign tumor occurring singly or as multiple synchronous lesions. The histologic features of renal oncocytoma may overlap with those of chromophobe renal cell carcinoma. Chromosomal translocations involving the CCND1 locus at 11q13 and overexpression of cyclin D1 occur in a subset of renal oncocytomas. We evaluated a series of 63 renal oncocytomas and 36 chromophobe renal cell carcinomas and assessed the clinical features, cyclin D1 overexpression by immunohistochemistry, and alterations of the CCND1 gene by fluorescence in situ hybridization. All 36 chromophobe renal cell carcinomas were negative for cyclin D1 overexpression and alterations of CCND1. Of the 63 renal oncocytomas, 21 (33%) showed cyclin D1 overexpression. Of 21 renal oncocytomas with cyclin D1 overexpression, a CCND1 rearrangement was detected in 12 (57%). A CCND1 rearrangement was also identified in 1 (2%) of the 42 renal oncocytomas without cyclin D1 overexpression. Of 42 renal oncocytomas without cyclin D1 overexpression, 16 (38%) were from patients with multiple renal oncocytomas at nephrectomy. Of 21 renal oncocytomas with cyclin D1 overexpression, only 1 (5%) patient had multiple renal oncocytomas (P = .006). Of the 25 patients whose original tumor showed no cyclin D1 overexpression, 8 (32%) developed a subsequent renal oncocytoma. None of 15 patients whose original tumor showed cyclin D1 overexpression had a subsequent renal oncocytoma (P = .016). The findings of this study suggest that renal oncocytomas lacking cyclin D1 overexpression may be associated with the development of multiple renal oncocytomas and that these patients are more likely to develop subsequent renal oncocytomas suggesting the need for more frequent clinical for these patients and little need for follow-up in patients with renal oncocytomas overexpressing cyclin D1. The data also show that cyclin D1 overexpression and CCND1 rearrangements by fluorescence in situ hybridization are absent in

  1. Upregulation of ATF-3 is correlated with prognosis and proliferation of laryngeal cancer by regulating Cyclin D1 expression

    PubMed Central

    Feng, Jiapeng; Sun, Qingfeng; Wu, Tianyi; Lu, Jianguang; Qu, Lingmei; Sun, Yanan; Tian, Linli; Zhang, Binghui; Li, Dandan; Liu, Ming

    2013-01-01

    Objective: This study aimed to investigate the expression and significance of ATF-3 in laryngeal squamous cell carcinoma (LSCC). Methods: Expression of ATF-3 was examined using immunohistochemistry methods in samples from 83 cases of LSCC carcinoma. MTT assay was used to detect proliferation of Hep-2 cells after ATF-3 knocked down by siRNA lentivirus. A mouse model was used to investigate the inhibitive role of ATF-3 siRNA in LSCC xenografts. Realtime RCR was used to detect Cyclin D1 expression after ATF-3 downregulation in Hep-2 cells. Results: The expression of ATF-3 was positively detected in all the 83 cases of LSCC cancer tissues while Only 4 cases of adjacent non-neoplastic tissues were detected with positive ATF-3 expression. The ATF-3 expression was statistically related with T stage, neck nodal metastasis, clinical stage and prognosis of LSCC. Both cell proliferation in vitro and tumor growth in vivo were suppressed after ATF-3 knockdown. Furthermore, the expression of Cyclin D1 was decreased after ATF-3 downregulation in Hep-2 cells. Conclusion: ATF-3 is involved in the progress of LSCC, and may provide clinical information for evaluation of prognosis of LSCC. The oncologic role of ATF-3 may be correlated with Cyclin D1 regulation. PMID:24133584

  2. Upregulation of ATF-3 is correlated with prognosis and proliferation of laryngeal cancer by regulating Cyclin D1 expression.

    PubMed

    Feng, Jiapeng; Sun, Qingfeng; Wu, Tianyi; Lu, Jianguang; Qu, Lingmei; Sun, Yanan; Tian, Linli; Zhang, Binghui; Li, Dandan; Liu, Ming

    2013-01-01

    This study aimed to investigate the expression and significance of ATF-3 in laryngeal squamous cell carcinoma (LSCC). Expression of ATF-3 was examined using immunohistochemistry methods in samples from 83 cases of LSCC carcinoma. MTT assay was used to detect proliferation of Hep-2 cells after ATF-3 knocked down by siRNA lentivirus. A mouse model was used to investigate the inhibitive role of ATF-3 siRNA in LSCC xenografts. Realtime RCR was used to detect Cyclin D1 expression after ATF-3 downregulation in Hep-2 cells. The expression of ATF-3 was positively detected in all the 83 cases of LSCC cancer tissues while Only 4 cases of adjacent non-neoplastic tissues were detected with positive ATF-3 expression. The ATF-3 expression was statistically related with T stage, neck nodal metastasis, clinical stage and prognosis of LSCC. Both cell proliferation in vitro and tumor growth in vivo were suppressed after ATF-3 knockdown. Furthermore, the expression of Cyclin D1 was decreased after ATF-3 downregulation in Hep-2 cells. ATF-3 is involved in the progress of LSCC, and may provide clinical information for evaluation of prognosis of LSCC. The oncologic role of ATF-3 may be correlated with Cyclin D1 regulation.

  3. HDAC1, HDAC4, and HDAC9 Bind to PC3/Tis21/Btg2 and Are Required for Its Inhibition of Cell Cycle Progression and Cyclin D1 Expression.

    PubMed

    Micheli, Laura; D'Andrea, Giorgio; Leonardi, Luca; Tirone, Felice

    2017-07-01

    PC3/Tis21 is a transcriptional cofactor that inhibits proliferation in several cell types, including neural progenitors. Here, we report that PC3/Tis21 associates with HDAC1, HDAC4, and HDAC9 in vivo, in fibroblast cells. Furthermore, when HDAC1, HDAC4, or HDAC9 are silenced in fibroblasts or in a line of cerebellar progenitor cells, the ability of PC3/Tis21 to inhibit proliferation is significantly reduced. Overexpression of HDAC1, HDAC4, or HDAC9 in fibroblasts and in cerebellar precursor cells synergizes with PC3/Tis21 in inhibiting the expression of cyclin D1, a cyclin selectively inhibited by PC3/Tis21. Conversely, the depletion of HDAC1 or HDAC4 (but not HDAC9) in fibroblasts and in cerebellar precursor cells significantly impairs the ability of PC3/Tis21 to inhibit cyclin D1 expression. An analysis of HDAC4 deletion mutants shows that both the amino-terminal moiety and the catalytic domain of HDAC4 associate to PC3/Tis21, but neither alone is sufficient to potentiate the inhibition of cyclin D1 by PC3/Tis21. As a whole, our findings indicate that PC3/Tis21 inhibits cell proliferation in a way dependent on the presence of HDACs, in fibroblasts as well as in neural cells. Considering that several reports have demonstrated that HDACs can act as transcriptional corepressors on the cyclin D1 promoter, our data suggest that the association of PC3/Tis21 to HDACs is functional to recruit them to target genes, such as cyclin D1, for repression of their expression. J. Cell. Physiol. 232: 1696-1707, 2017. © 2016 Wiley Periodicals, Inc.

  4. Spontaneous peripheral T-cell responses toward the tumor-associated antigen cyclin D1 in patients with clear cell renal cell carcinoma.

    PubMed

    Dannenmann, Stefanie R; Hermanns, Thomas; Bransi, Ali; Matter, Claudia; von Boehmer, Lotta; Stevanovic, Stefan; Schraml, Peter; Moch, Holger; Knuth, Alexander; van den Broek, Maries

    2013-11-01

    Renal cell carcinoma (RCC) is a heterogeneous group of kidney cancers with clear cell RCC (ccRCC) as the major subgroup. To expand the number of clinically relevant tumor-associated antigens (TAA) that can be targeted by immunotherapy, we analyzed samples from 23 patients with primary ccRCC for the expression and immunogenicity of various TAAs. We found high-frequency expression of MAGE-A9 and NY-ESO-1 in 36% and 55% of samples, respectively, and overexpression of PRAME, RAGE-1, CA-IX, Cyclin D1, ADFP, C-MET, and RGS-5 in many of the tumor samples. We analyzed the blood of patients with HLA-A2(+) ccRCC for the presence of CD8(+) T cells specific for TAA-derived HLA-A2-restricted peptides and found spontaneous responses to cyclin D1 in 5 of 6 patients with Cyclin D1-positive tumors. Cyclin D1-specific CD8(+) T cells secreted TNF-α, IFN-γ, and interleukin-2 (IL-2), and degranulated, indicating the presence of polyfunctional tumor-specific CD8(+) T cells in the blood of these patients with ccRCC. The high frequency (43%) of Cyclin D1 overexpression and the presence of functional cyclin D1-specific T cells in 83% of these patients with ccRCC suggest that cyclin D1 may be a target for immunotherapeutic strategies.

  5. Molecular and immunochemical analyses of RB1 and cyclin D1 in human ductal pancreatic carcinomas and cell lines.

    PubMed

    Huang, L; Lang, D; Geradts, J; Obara, T; Klein-Szanto, A J; Lynch, H T; Ruggeri, B A

    1996-02-01

    Somatic mutations in the retinoblastoma-1 gene (RB1) and loss of RB1 protein function have been implicated in a number of human malignancies, but the role of RB1 gene and protein abnormalities in ductal pancreatic cancer (DPCA) is virtually unknown. We therefore analyzed expression of the RB1 protein immunohistochemically and/or by western blotting in a total of 54 sporadic and eight familial cases of archival and frozen DPCA and in 18 pancreatic carcinoma cell lines by using the antibodies RB-WL-1, 84-B3-1, and PMG3-245. Mutations in the RB1 promotor region and exons 13-21 of the RB1 gene were likewise examined by single-strand conformation polymorphism (SSCP) analyses and DNA sequencing of genomic DNA from 30 microdissected primary pancreatic tumors and the pancreatic carcinoma cell lines. Moreover, amplification and expression of a major regulatory component of RB1 function, cyclin D1, were assessed by southern and immunohistochemical analyses, respectively. The DPCAs were heterogeneous in both the intensity of RB1 nuclear staining and the percentage of immunoreactive cells. The tumors often had areas where RB1 staining was weak or absent adjacent to normal pancreatic tissue; however, only two of 32 archival cases and one of 30 frozen cases of DPCA completely lacked RB1 nuclear staining. Immunohistochemical and western blot analyses of 18 pancreatic carcinoma cell lines demonstrated the absence of RB1 expression in only two cell lines, Capan-1 and QGP-1. Analyses of the RB1 gene and promotor region by SSCP and DNA sequencing largely confirmed the immunochemical findings. Three of 30 primary carcinomas had abnormalities revealed by SSCP analyses. In one case a single base-pair deletion was confirmed in exon 18 and resulted in premature termination and the absence of detectable RB1 protein. A second case had TAC-->TTC missense mutation in exon 13. The third primary carcinoma could not be reliably sequenced because it had a low percentage of epithelial cells. The

  6. DNA tumor virus oncoproteins and retinoblastoma gene mutations share the ability to relieve the cell's requirement for cyclin D1 function in G1

    PubMed Central

    1994-01-01

    The retinoblastoma gene product (pRB) participates in the regulation of the cell division cycle through complex formation with numerous cellular regulatory proteins including the potentially oncogenic cyclin D1. Extending the current view of the emerging functional interplay between pRB and D-type cyclins, we now report that cyclin D1 expression is positively regulated by pRB. Cyclin D1 mRNA and protein is specifically downregulated in cells expressing SV40 large T antigen, adenovirus E1A, and papillomavirus E7/E6 oncogene products and this effect requires intact RB-binding, CR2 domain of E1A. Exceptionally low expression of cyclin D1 is also seen in genetically RB-deficient cell lines, in which ectopically expressed wild-type pRB results in specific induction of this G1 cyclin. At the functional level, antibody-mediated cyclin D1 knockout experiments demonstrate that the cyclin D1 protein, normally required for G1 progression, is dispensable for passage through the cell cycle in cell lines whose pRB is inactivated through complex formation with T antigen, E1A, or E7 oncoproteins as well as in cells which have suffered loss-of-function mutations of the RB gene. The requirement for cyclin D1 function is not regained upon experimental elevation of cyclin D1 expression in cells with mutant RB, while reintroduction of wild-type RB into RB-deficient cells leads to restoration of the cyclin D1 checkpoint. These results strongly suggest that pRB serves as a major target of cyclin D1 whose cell cycle regulatory function becomes dispensable in cells lacking functional RB. Based on available data including this study, we propose a model for an autoregulatory feedback loop mechanism that regulates both the expression of the cyclin D1 gene and the activity of pRB, thereby contributing to a G1 phase checkpoint control in cycling mammalian cells. PMID:8175885

  7. Targeting the AKT/GSK3{beta}/Cyclin D1/Cdk4 Survival Signaling Pathway for Eradication of Tumor Radioresistance Acquired by Fractionated Radiotherapy

    SciTech Connect

    Shimura, Tsutomu; Kakuda, Satoshi; Ochiai, Yasushi; Kuwahara, Yoshikazu; Takai, Yoshihiro; Fukumoto, Manabu

    2011-06-01

    Purpose: Radioresistance is a major cause of treatment failure of radiotherapy (RT) in human cancer. We have recently revealed that acquired radioresistance of tumor cells induced by fractionated radiation is attributable to cyclin D1 overexpression as a consequence of the downregulation of GSK3{beta}-dependent cyclin D1 proteolysis mediated by a constitutively activated serine-threonine kinase, AKT. This prompted us to hypothesize that targeting the AKT/GSK3{beta}/cyclin D1 pathway may improve fractionated RT by suppressing acquired radioresistance of tumor cells. Methods and Materials: Two human tumor cell lines with acquired radioresistance were exposed to X-rays after incubation with either an AKT inhibitor, AKT/PKB signaling inhibitor-2 (API-2), or a Cdk4 inhibitor (Cdk4-I). Cells were then subjected to immunoblotting, clonogenic survival assay, cell growth analysis, and cell death analysis with TUNEL and annexin V staining. In vivo radiosensitivity was assessed by growth of human tumors xenografted into nude mice. Results: Treatment with API-2 resulted in downregulation of cyclin D1 expression in cells with acquired radioresistance. Cellular radioresistance disappeared completely both in vitro and in vivo with accompanying apoptosis when treated with API-2. Furthermore, inhibition of cyclin D1/Cdk4 by Cdk4-I was sufficient for abolishing radioresistance. Treatment with either API-2 or Cdk4-I was also effective in suppressing resistance to cis-platinum (II)-diamine-dichloride in the cells with acquired radioresistance. Interestingly, the radiosensitizing effect of API-2 was canceled by overexpression of cyclin D1 whereas Cdk4-I was still able to sensitize cells with cyclin D1 overexpression. Conclusion: Cyclin D1/Cdk4 is a critical target of the AKT survival signaling pathway responsible for tumor radioresistance. Targeting the AKT/GSK3{beta}/cyclin D1/Cdk4 pathway would provide a novel approach to improve fractionated RT and would have an impact on tumor

  8. Quercetin reduces cyclin D1 activity and induces G1 phase arrest in HepG2 cells.

    PubMed

    Zhou, Jin; Li, L U; Fang, L I; Xie, Hua; Yao, Wenxiu; Zhou, Xiang; Xiong, Zhujuan; Wang, L I; Li, Zhixi; Luo, Feng

    2016-07-01

    Quercetin is able to inhibit proliferation of malignant tumor cells; however, the exact mechanism involved in this biological process remains unclear. The current study utilized a quantitative proteomic analysis to explore the antitumor mechanisms of quercetin. The leucine of HepG2 cells treated with quercetin was labeled as d3 by stable isotope labeling by amino acids in cell culture (SILAC). The isotope peaks of control HepG2 cells were compared with the d3-labeled HepG2 cells by mass spectrometry (MS) to identify significantly altered proteins. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot analyses were subsequently employed to verify the results of the MS analysis. A flow cytometry assay was designed to observe the influence of various quercetin treatment concentrations on the cell cycle distribution of HepG2 cells. The results indicated that quercetin is able to substantially inhibit proliferation of HepG2 cells and induce an obvious morphological alteration of cells. According to the MS results, the 70 credibly-changed proteins that were identified may play important roles in multiple cellular processes, including protein synthesis, signaling, cytoskeletal processes and metabolism. Among these functional proteins, the expression of cyclin D1 (CCND1) was found to be significantly decreased. RT-PCR and western blot analyses verified the SILAC-MS results of decreased CCND1 expression. In summary, flow cytometry revealed that quercetin is able to induce G1 phase arrest in HepG2 cells. Based on the aforementioned observations, it is suggested that quercetin exerts antitumor activity in HepG2 cells through multiple pathways, including interfering with CCND1 gene expression to disrupt the cell cycle and proliferation of HepG2 cells. In the future, we aim to explore this effect in vivo.

  9. IMP-3 protects the mRNAs of cyclins D1 and D3 from GW182/AGO2-dependent translational repression.

    PubMed

    Deforzh, Evgeny; Vargas, Thaiz Rivera; Kropp, Jeremie; Vandamme, Marie; Pinna, Guillaume; Polesskaya, Anna

    2016-12-01

    IGF-2 mRNA binding protein 3 (IGF2BP3, IMP-3) is a well-known post-transcriptional regulatory factor of gene expression, mainly involved in embryonic development and oncogenesis. We have previously demonstrated that a subset of IMP-3 targets, such as the mRNAs of cyclins D1, D3 and G1, are positively regulated by IMP-3, and that this regulation depends on nuclear localization of IMP-3. In the present study, we show that as a first step following a knock-down of IMP-3, the protein levels of the cyclins rapidly decrease, while their mRNAs remain stable and associated with the polyribosomes, though not translated. We have elucidated the molecular mechanisms of this regulation, demonstrating that IMP-3 and its protein partners ILF3/NF90 and PTBP1 bind to the 3'UTRs of the cyclin mRNAs and protect them from the translational repression induced by miRNA-dependent recruitment of AGO2/GW182 complex in human cancer cells.

  10. 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

  11. A cyclin D1-negative mantle cell lymphoma with an IGL-CCND2 translocation that relapsed with blastoid morphology and aggressive clinical behavior.

    PubMed

    Kurita, Daisuke; Takeuchi, Kengo; Kobayashi, Sumiko; Hojo, Atsuko; Uchino, Yoshihito; Sakagami, Masashi; Ohtake, Shimon; Takahashi, Hiromichi; Miura, Katsuhiro; Iriyama, Noriyoshi; Sugitani, Masahiko; Miyoshi, Hiroaki; Hatta, Yoshihiro; Ohshima, Koichi; Takei, Masami

    2016-10-01

    Mantle cell lymphoma (MCL) is a B cell neoplasm characterized by cyclin D1 overexpression; its prognosis is poor, especially when it exhibits a blastoid morphology. Cyclin D1-negative MCL is rare, and its pathogenesis and progression remain unclear. Herein, we describe a cyclin D1-negative, cyclin D2-positive MCL with a CCND2 and immunoglobulin lambda light chain (IGL) translocation. The patient was initially diagnosed with cyclin D1-negative MCL and achieved complete remission via combination chemotherapy and autologous stem cell transplantation. After relapsing, he was diagnosed with a blastoid variant of MCL that showed lymphoid cells with dispersed chromatin and more mitotic figures and higher p53 expression compared with the initial MCL. Despite salvage therapies, the disease became refractory, and the patient died 28 months after initiating chemotherapy. This case demonstrates that blastoid morphology in cyclin D1-negative MCL with IGL-CCND2 translocation indicates progression to a more aggressive neoplasm, similar to cyclin D1-positive MCL.

  12. A Human Long Non-Coding RNA ALT1 Controls the Cell Cycle of Vascular Endothelial Cells Via ACE2 and Cyclin D1 Pathway.

    PubMed

    Li, Wen; Wang, Rui; Ma, Jie-Yi; Wang, Mian; Cui, Jin; Wu, Wei-Bin; Liu, Rui-Ming; Zhang, Chun-Xiang; Li, Wen; Wang, Shen-Ming

    2017-10-05

    ALT1 is a novel long non-coding RNA derived from the alternatively spliced transcript of the deleted in lymphocytic leukemia 2 (DLEU2). To date, ALT1 biological roles in human vascular endothelial cells have not been reported. ALT1 was knocked down by siRNAs. Cell proliferation was analyzed by cck-8. The existence and sequence of human ALT1 were identified by 3' rapid amplification of cDNA ends. The interaction between lncRNA and proteins was analyzed by RNA-Protein pull down assay, RNA immunoprecipitation, and mass spectrometry analysis. ALT1 was expressed in human umbilical vein endothelial cells (HUVECs). The expression of ALT1 was significantly downregulated in contact-inhibited HUVECs and in hypoxia-induced, growth-arrested HUVECs. Knocking down of ALT1 inhibited the proliferation of HUVECs by G0/G1 cell cycle arrest. We observed that angiotensin converting enzyme Ⅱ(ACE2) was a direct target gene of ALT1. Knocking-down of ALT1 or its target gene ACE2 could efficiently decrease the expression of cyclin D1 via the enhanced ubiquitination and degradation, in which HIF-1α and protein von Hippel-Lindau (pVHL) might be involved. The results suggested the human long non-coding RNA ALT1 is a novel regulator for cell cycle of HUVECs via ACE2 and cyclin D1 pathway. © 2017 The Author(s). Published by S. Karger AG, Basel.

  13. p53 mutation and cyclin D1 amplification correlate with cisplatin sensitivity in xenografted human squamous cell carcinomas from head and neck.

    PubMed

    Henriksson, Eva; Baldetorp, Bo; Borg, Ake; Kjellen, Elisabeth; Akervall, Jan; Wennerberg, Johan; Wahlberg, Peter

    2006-01-01

    To investigate the response of tumour growth to cisplatin treatment, in relation to p53 mutation and cyclin D1 dysregulation on DNA and protein level, biopsies from seven xenografted human squamous cell carcinomas from the head and neck were analysed with immunohistochemistry for p53 expression and cyclin D1 expression. Polymerase chain reaction-singlestranded conformation polymorphism was used to determine p53 mutations. Fluorescence in situ hybridization was performed to analyse cyclin D1 amplification. The mice were injected i.p. with NaCl (controls) or cisplatin. After injection the tumour volume were measured. The inhibition of tumour growth by cisplatin was defined as the area under the growth curves, and compared with the growth curves of the tumours in the control group. Xenografts with p53 mutation showed significantly higher resistance to cisplatin (p < 0.001) and also tumours with cyclin D1 amplification showed significantly higher resistance (p < 0.001).

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

    SciTech Connect

    Li, Tianjia; Song, Ting; Ni, Leng; Yang, Genhuan; Song, Xitao; Wu, Lifei; Liu, Bao; Liu, Changwei

    2014-10-24

    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 exerted 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.

  15. Cyclin D1 is a useful marker for soft tissue Ewing's sarcoma/peripheral Primitive Neuroectodermal Tumor in children and adolescents: A comparative immunohistochemical study with rhabdomyosarcoma.

    PubMed

    Magro, Gaetano; Brancato, Franca; Musumeci, Giuseppe; Alaggio, Rita; Parenti, Rosalba; Salvatorelli, Lucia

    2015-01-01

    Cyclin D1 amplification and/or overexpression contribute to the loss of the regulatory circuits that govern G1-S transition phase of the cell cycle, playing pivotal roles in different human malignant tumors, including breast, colon, prostate cancer, lymphoma, melanoma and neuroblastoma. In vitro studies have shown that cyclin D1 is overexpressed in Ewing's sarcoma (EWS)/peripheral Primitive Neuroectodermal Tumor (pPNET), but not in rhabdomyosarcoma cell lines. Only a few immunohistochemical studies are available on cyclin D1 expression in EWS/pPNET, which confirmed its expression only in a limited number of cases. The aim of the present study was a comparative immunohistochemical analysis of the expression and distribution of cyclin D1 in a large series of pediatric/adolescent soft tissue EWS/pPNETs and rhabdomyosarcomas (both embryonal and alveolar subtypes) to assess its potential usefulness in their differential diagnosis. Notably cyclin D1 was strongly and diffusely expressed in all cases (20/20) of EWS/pPNET, while it was lacked in all cases (15/15) of rhabdomyosarcomas. Immunohistochemical overexpression of cyclin D1 in EWS/pPNET is a novel finding which could be exploitable as a diagnostic immunomarker for this tumor. Although highly sensitive, cyclin D1 is not specific for EWS/pPNET, and thus it should not be evaluated alone but in the context of a wide immunohistochemical panel. Accordingly, we first emphasize that when pathologists are dealing with a small round blue cell tumor of soft tissues in pediatric/adolescent patients, a strong and diffuse nuclear expression of cyclin D1 is of complementary diagnostic value to CD99 and FLI-1 in confirming diagnosis of EWS/pPNET and in ruling out rhabdomyosarcoma.

  16. Cdk2 plays a critical role in hepatocyte cell cycle progression and survival in the setting of cyclin D1 expression in vivo.

    PubMed

    Hanse, Eric A; Nelsen, Christopher J; Goggin, Melissa M; Anttila, Chelsea K; Mullany, Lisa K; Berthet, Cyril; Kaldis, Philipp; Crary, Gretchen S; Kuriyama, Ryoko; Albrecht, Jeffrey H

    2009-09-01

    Cdk2 was once believed to play an essential role in cell cycle progression, but cdk2(-/-) mice have minimal phenotypic abnormalities. In this study, we examined the role of cdk2 in hepatocyte proliferation, centrosome duplication and survival. Cdk2(-/-) hepatocytes underwent mitosis and had normal centrosome content after mitogen stimulation. Unlike wild-type cells, cdk2(-/-) liver cells failed to undergo centrosome overduplication in response to ectopic cyclin D1 expression. After mitogen stimulation in culture or partial hepatectomy in vivo, cdk2(-/-) hepatocytes demonstrated diminished proliferation. Cyclin D1 is a key mediator of cell cycle progression in hepatocytes, and transient expression of this protein is sufficient to promote robust proliferation of these cells in vivo. In cdk2(-/-) mice and animals treated with the cdk2 inhibitor seliciclib, cyclin D1 failed to induce hepatocyte cell cycle progression. Surprisingly, cdk2 ablation or inhibition led to massive hepatocyte and animal death following cyclin D1 transfection. In a transgenic model of chronic hepatic cyclin D1 expression, seliciclib induced hepatocyte injury and animal death, suggesting that cdk2 is required for survival of cyclin D1-expressing cells even in the absence of substantial proliferation. In conclusion, our studies demonstrate that cdk2 plays a role in liver regeneration. Furthermore, it is essential for centrosome overduplication, proliferation and survival of hepatocytes that aberrantly express cyclin D1 in vivo. These studies suggest that cdk2 may warrant further investigation as a target for therapy of liver tumors with constitutive cyclin D1 expression.

  17. Hypoxia, angiotensin-II, and norepinephrine mediated apoptosis is stimulus specific in canine failed cardiomyocytes: a role for p38 MAPK, Fas-L and cyclin D1.

    PubMed

    Sharov, Victor G; Todor, Anastassia; Suzuki, George; Morita, Hideaki; Tanhehco, Elaine J; Sabbah, Hani N

    2003-03-01

    Apoptosis may contribute to the myocardial dysfunction associated with heart failure (HF). Activation of the p38 MAPK cascade can induce apoptosis in non-cardiac cells through increased expression of Fas-L, or through decreased expression of cyclin D(1). We tested the hypothesis that hypoxia (HX), angiotensin-II (A-II) and norepinephrine (NEPI) can mediate apoptosis by activating p38 MAPK, and thus initiating stimulus specific changes in Fas-L and cyclin D(1) expression in failing cardiomyocytes. Cardiomyocytes isolated from ten dogs with HF induced by coronary microembolizations were subjected to HX or A-II or NEPI with and without a p38 MAPK inhibitor (SB 203580). TUNEL staining for DNA fragmentation and Western blots for p38 MAPK, Fas-L and cyclin D(1) detection were performed. HX-induced apoptosis was associated with increased Fas-L expression, A-II-induced apoptosis was associated with increased Fas-L and decreased cyclin D(1) expression, and NEPI-induced apoptosis was associated with decreased cyclin D(1) expression. Inhibition of p38 MAPK activity attenuated stress-induced apoptosis in all experiments and reversed changes in Fas-L and cyclin D(1) expression. HX, A-II and NEPI mediate apoptosis in failing cardiomyocytes via different effects on Fas-L and cyclin D(1) expression. Inhibition of p38 MAPK reversed these effects, suggesting that apoptosis induced by HX, A-II and NEPI involves activation of p38 MAPK upstream from Fas-L and cyclin D(1).

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

    SciTech Connect

    Pan, Christopher C.; Bloodworth, Jeffrey C.; Mythreye, Karthikeyan; Lee, Nam Y.

    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 previously 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.

  19. Altered expression of cell cycle regulators Cyclin D1, p14, p16, CDK4 and Rb in nodular melanomas.

    PubMed

    Bachmann, Ingeborg M; Straume, Oddbjørn; Akslen, Lars A

    2004-12-01

    Cell cycle regulating proteins are important in tumour development. To investigate whether alterations in Cyclin D1, p14, CDK4 and Rb are associated with tumour cell proliferation, tumour progression and patient survival in malignant melanoma, we examined 202 vertical growth phase tumours and 68 corresponding metastases for expression of Cyclin D1, p14, CDK4 and Rb, and compared the results with Ki-67 expression, p16 and p53 expression, clinico-pathological variables, and survival data. Nuclear staining of Cyclin D1 was strong in 35% of cases, and correlated with high levels of Rb (p=0.05), but not with survival or other markers tested. Strong staining of p14 was found in 63% of nodular melanomas and was associated with strong p53 expression (p=0.014), and with high levels of CDK4 (p<0.0001). Low p14 expression was associated with increased tumour thickness (p=0.008) and increasing level of invasion (p=0.020). Strong nuclear staining for CDK4 was found in 81% of cases and was associated with tumour thickness below the median value of 3.7 mm and improved survival (log-rank test, p=0.024). Further, 56% of the tumours showed strong nuclear staining for Rb, and these cases were significantly associated with absent/low levels of p16 staining (p=0.030), high levels of p14 (p=0.010), as well as high Ki-67 expression (p=0.005). Our results seem to confirm that the p16-Rb pathway plays an important role in tumour progression and prognosis in vertical growth phase melanomas, whereas alterations in the p14-p53 pathway might be less important.

  20. Abrogation of the p16-retinoblastoma-cyclin D1 pathway in head and neck squamous cell carcinomas.

    PubMed

    Park, Hun-Woong; Song, Si-Youn; Lee, Tae-Jin; Jeong, Daewon; Lee, Tae-Yoon

    2007-07-01

    In the present study, we analyzed p16, retinoblastoma (Rb), and cyclin D1 abnormalities in head and neck squamous cell carcinoma (HNSCC) tissues and cell lines from Korean patients. We found a 40% loss of heterozygosity at the D9S171 locus (9p21 region) these tissues. All eight of the HNSCC cell lines did not express the p16 protein, and in two of these cell lines (Amc-HN-6 and 8), this was due to a deletion of the p16 gene. Three of the cell lines (Amc-HN-3 to 5) that expressed the p16 mRNA had the same nonsense mutation at codon 50 (CGA-Arg to TGA-Ter). The Amc-HN-1 and Amc-HN-7 cell lines, which did not express the p16 mRNA, had a missense mutation at codon 9 (GCC-Ala to GTC-Val) and a silent mutation at codon 106 (CCC-Pro to CCA), respectively. The Amc-HN-2 cell line (p16 exon-positive/mRNA-negative) had a single base deletion at codon 38 (CGG-Arg to CG), which resulted in a frameshift and a consequent stop signal at codon 44. The Rb protein was detected in all of the eight cell lines, although it was inactive in five of these due to hyperphosphorylation. The inverse relationship between p16 and Rb was 62.5% (5/8). Cyclin D1 was overexpressed in all of the eight cell lines. Our results suggest that the abrogation of p16, the overexpression of cyclin D1, and the consequent inactivation of Rb could be important factors in the carcinogenesis of HNSCCs.

  1. The p16-cyclin D1/CDK4-pRb pathway and clinical outcome in epithelial ovarian cancer.

    PubMed

    Kusume, T; Tsuda, H; Kawabata, M; Inoue, T; Umesaki, N; Suzuki, T; Yamamoto, K

    1999-12-01

    A significant positive association has been reported between p16 expression and clinical outcome for epithelial ovarian cancer patients. However, there is a reciprocal correlation between genetic alterations of single members of the p16-cyclin D1/CDK4-pRb pathway (G1 pathway). Simultaneous evaluation of these four elements may produce a better prognostic factor than p16 alone. We studied the prognostic significance of the G1 pathway in 59 epithelial ovarian cancer patients undergoing surgery and platinum-based chemotherapy by immunohistochemical technique. Abnormal expression of p16 or pRb was defined by negative nuclei staining, and that of CDK4 and cyclin D1 was defined by 50% nuclear staining. An abnormal G1 pathway was indicated in cases that have at least one abnormality among these four elements. Abnormal expression of p16, pRb, and cyclin D1/CDK4 was observed in 33.9, 3.4, and 15.3% of studied cases, respectively. Abnormal G1 pathway was detected in 49.2% (29 of 59) of all cases. The patients with normal G1 pathway tended to achieve a higher complete response rate (81.0%) to chemotherapy, compared with patients with abnormal G1 pathway (55.0%); however, there was no significant difference (P = 0.1001) between the two groups. Univariate analyses identified advanced stage [hazards ratio (HR), 3.665; P = 0.0218], histological low grade (HR, 3.625; P = 0.0066), and abnormal G1 pathway (HR, 2.935; P = 0.03) as prognostic factors for overall survival. The G1 pathway might help as a prognostic factor to select high-risk patients.

  2. Rapamycin inhibits prostate cancer cell growth through cyclin D1 and enhances the cytotoxic efficacy of cisplatin

    PubMed Central

    Imrali, Ahmet; Mao, Xueying; Yeste-Velasco, Marc; Shamash, Jonathan; Lu, Yongjie

    2016-01-01

    Prostate cancer is the most common malignancy in Western men and hormone refractory cancer (HRPC) kills most of the patients. Chemo-resistance is a major obstacle for the treatment of prostate cancer. Platinum-complexes have been used to treat a number of malignancies including prostate cancer. However, it has limited effect to prostate cancer and with significant toxicity at higher doses. In recent years, increasing numbers of new agents targeting cancer specific pathways have become available and with low toxic side-effects. Rapamycin (Sirolimus) is an mTORC1 inhibitor, which inhibits the PI3K/Akt/mTOR signaling pathway, which is commonly altered in prostate cancer. We determined the expression of cyclin D1 and phosphorylated-mTOR proteins in association with the response to rapamycin in two androgen sensitive (22RV1 and LNCaP) and two androgen independent (DU145 and PC3) prostate cancer cell lines and found that the base-line and changes of cyclin D1 level, but not the expression level of p-mTOR, correlated with rapamycin sensitivity. We evaluated the cell killing effect of combined rapamycin and cisplatin treatment and showed that the combination had a more than additive effect in both androgen dependent and independent prostate cancer cells, which may be partially explained by the reduction of cyclin D1 expression by rapamycin. We also evaluated a range of combined treatment schedules, simultaneously or sequentially and found that continuous rapamycin treatment after a short cisplatin exposure was effective. The clinical application of these findings for prostate cancer treatment should be further investigated. PMID:27648364

  3. Regulation of estrogen receptor transcriptional enhancement by the cyclin A/Cdk2 complex.

    PubMed

    Trowbridge, J M; Rogatsky, I; Garabedian, M J

    1997-09-16

    We have found that ectopic expression of cyclin A increases hormone-dependent and hormone-independent transcriptional activation by the estrogen receptor in vivo in a number of cell lines, including HeLa cells, U-2 OS osteosarcoma cells and Hs 578Bst breast epithelial cells. This effect can be further enhanced in HeLa cells by the concurrent expression of the cyclin-dependent kinase activator, cyclin H, and cdk7, and abolished by expression of the cdk inhibitor, p27(KIP1), or by the expression of a dominant negative catalytically inactive cdk2 mutant. ER is phosphorylated between amino acids 82 and 121 in vitro by the cyclin A/cdk2 complex and incorporation of phosphate into ER is stimulated by ectopic expression of cyclin A in vivo. Together, these results strongly suggest a direct role for the cyclin A/cdk2 complex in phosphorylating ER and regulating its transcriptional activity.

  4. A cyclin D1-positive diffuse large B-cell lymphoma of germinal center B-cell-like subtype in the right tonsil

    PubMed Central

    Jiang, Changrui; Shi, Xiuying; Fan, Chuifeng

    2017-01-01

    Abstract Introduction: Cyclin D1-positive tumor cells are commonly found in mantle cell lymphoma but they are very rare in diffuse large B-cell lymphoma. Clinical findings/Patient concerns: Here we present a rare case of cyclin D1-positive diffuse large B-cell lymphoma in the right tonsil of a 50-year-old man. Computed tomographic imaging detected a mass, about 2.5 cm × 1.8 cm in size, in the left side of the oropharynx. Diagnoses: Microscopically, the tumor cells were located under the pharyngeal mucosa and diffusely arranged. The tumor cells were large, with marked nuclear atypia. On performing immunohistochemistry, the tumor cells showed diffuse positive staining for CD10, CD20, cyclin D1, and Pax-5, and negative staining for CD3, CD15, CD30, CD56, and CK. Bcl-6 and Mum-1 expression were observed in 60% and 80% of tumor cells, respectively. The tumor Ki67 index was about 60%. Based on these findings, The tumor was diagnosed as a rare cyclin D1-positive diffuse large B-cell lymphoma rather than a mantle cell lymphoma. Conclusion: Cyclin D1-positive large B-cell lymphoma is rare, but as large B-cell lymphoma is a common type of lymphoma, cyclin D1-positive large B-cell lymphoma should be considered a major possibility during differential diagnosis, including in the tonsils. PMID:28296741

  5. MicroRNA-155 inhibits proliferation and migration of human extravillous trophoblast derived HTR-8/SVneo cells via down-regulating cyclin D1.

    PubMed

    Dai, Y; Qiu, Z; Diao, Z; Shen, L; Xue, P; Sun, H; Hu, Y

    2012-10-01

    MiR-155 is known to participate in various cellular processes by targeting gene expression. We previously revealed a link between miR-155 and perturbation of trophoblast invasion and differentiation. This study aimed to investigate the target molecule(s) of miR-155 on the influence on the proliferation and migration of trophoblast cells. Bioinformatics analysis showed that, at the 3' untranslated region (UTR) of cyclin D1, six bases are complementary to the seed region of miR-155. Luciferase assays and cyclin D1 3'UTR transfection assays validated that cyclin D1 3'UTR was the target of miR-155 in HTR-8/SVneo cells. Overexpression of miR-155 in HTR-8/SVneo cells reduced the level of cyclin D1 protein, decreased cell proliferation and invasion, and increased cell number at the G1 stage. Furthermore, the increased expression of miR-155 also regulated the protein levels of kinase inhibitory protein p27 and phosphorylated cytoskeletal protein filamin A. In conclusion, we found that cyclin D1 may be a target of miR-155 in HTR-8/SVneo cells, and demonstrated a negative regulatory role of miR-155 involved in cyclin D1/p27 pathway in proliferation and migration of the cells.

  6. Anticancer effect of icaritin inhibits cell growth of colon cancer through reactive oxygen species, Bcl-2 and cyclin D1/E signaling.

    PubMed

    Li, Chaofeng; Peng, Weichao; Song, Xin; Wang, Qian; Wang, Wenyue

    2016-11-01

    Icaritin has an advantage in enhancing immunity. Besides, with its anticancer effect, it may be of great help in cancer treatment and recovery of cancer patients. As a result, icaritin is likely to become a novel anticancer drug. However, the anticancer effect of icaritin against colon cancer has not been elucidated thus far. The present study investigated the latent anticancer effect of icaritin on the inhibition of colon cancer cell growth by regulating reactive oxygen species (ROS), B-cell lymphoma (Bcl)-2 and cyclin D1/E signaling. The COLO-205 colon cancer cell line was used as a colon cancer cell model in the present study. First, cell growth and apoptosis were measured to analyze the anticancer effect of icaritin against colon cancer. Next, the possible mechanism of icaritin against colon cancer, including ROS, Bcl-2, cyclin D1, cyclin E and caspase-3/9, was explored. The results revealed that icaritin could inhibit cell growth and induce the apoptosis of COLO-205 cells. In addition, icaritin significantly induced ROS generation, suppressed Bcl-2, cyclin D1 and cyclin E protein expression, and activated caspase-3/9 activity in COLO-205 cells. The present findings demonstrated that icaritin exerted antiproliferative and anticancer effects against colon cancer through the activation of ROS generation and the suppression of Bcl-2, cyclin D1 and cyclin E signaling.

  7. Anticancer effect of icaritin inhibits cell growth of colon cancer through reactive oxygen species, Bcl-2 and cyclin D1/E signaling

    PubMed Central

    Li, Chaofeng; Peng, Weichao; Song, Xin; Wang, Qian; Wang, Wenyue

    2016-01-01

    Icaritin has an advantage in enhancing immunity. Besides, with its anticancer effect, it may be of great help in cancer treatment and recovery of cancer patients. As a result, icaritin is likely to become a novel anticancer drug. However, the anticancer effect of icaritin against colon cancer has not been elucidated thus far. The present study investigated the latent anticancer effect of icaritin on the inhibition of colon cancer cell growth by regulating reactive oxygen species (ROS), B-cell lymphoma (Bcl)-2 and cyclin D1/E signaling. The COLO-205 colon cancer cell line was used as a colon cancer cell model in the present study. First, cell growth and apoptosis were measured to analyze the anticancer effect of icaritin against colon cancer. Next, the possible mechanism of icaritin against colon cancer, including ROS, Bcl-2, cyclin D1, cyclin E and caspase-3/9, was explored. The results revealed that icaritin could inhibit cell growth and induce the apoptosis of COLO-205 cells. In addition, icaritin significantly induced ROS generation, suppressed Bcl-2, cyclin D1 and cyclin E protein expression, and activated caspase-3/9 activity in COLO-205 cells. The present findings demonstrated that icaritin exerted antiproliferative and anticancer effects against colon cancer through the activation of ROS generation and the suppression of Bcl-2, cyclin D1 and cyclin E signaling. PMID:27900033

  8. Malnutrition suppresses cell cycle progression of hematopoietic progenitor cells in mice via cyclin D1 down-regulation.

    PubMed

    Nakajima, Karina; Crisma, Amanda R; Silva, Graziela B; Rogero, Marcelo M; Fock, Ricardo A; Borelli, Primavera

    2014-01-01

    Protein malnutrition (PM) often is associated with changes in bone marrow (BM) microenvironment leading to an impaired hematopoiesis; however, the mechanism involved is poorly understood. The aim of this study was to compare the cell cycle progression of hematopoietic stem cells (HSC) and hematopoietic progenitor cells (HPC) and evaluate the cell cycle signaling in malnourished mice to assess the mechanism of cell cycle arrest. C57Bl/6J mice were randomly assigned in control and malnourished groups receiving normoproteic and hypoproteic diets (12% and 2% protein, respectively) over a 5-wk period. Nutritional and hematologic parameters were assessed and BM immunophenotypic analysis was performed. Cell cycle of HPC (Lin(-)) and HSC (Lin(-)Sca-1(+)c-Kit(+)) were evaluated after 6 h of in vivo 5-bromo-2'-deoxyuridine (BrDU) incorporation. Cell cycle regulatory protein expression of HPC was assessed by Western blot. Malnourished mice showed lower levels of serum protein, albumin, glucose, insulin-like growth factor-1, insulin, and higher levels of serum corticosterone. PM also caused a reduction of BM myeloid compartment resulting in anemia and leukopenia. After 6 h of BrDU incorporation, malnourished mice showed G0-G1 arrest of HPC without changes of HSC proliferation kinetics. HPC of malnourished mice showed reduced expression of proteins that induce cell cycle (cyclin D1, cyclin E, pRb, PCNA, Cdc25a, Cdk2, and Cdk4) and increased expression of inhibitory proteins (p21 and p27) with no significant difference in p53 expression. PM suppressed cell cycle progression mainly of HPC. This occurred via cyclin D1 down-regulation and p21/p27 overexpression attesting that BM microenvironment commitment observed in PM is affecting cell interactions compromising cell proliferation. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Coffee polyphenols change the expression of STAT5B and ATF-2 modifying cyclin D1 levels in cancer cells.

    PubMed

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

    2012-01-01

    Epidemiological studies suggest that coffee consumption reduces the risk of cancer, but the molecular mechanisms of its chemopreventive effects remain unknown. 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. 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. Coffee polyphenols are able to affect cyclin D1 expression in cancer cells through the modulation of STAT5B and ATF-2.

  10. The ATM and ATR inhibitors CGK733 and caffeine suppress cyclin D1 levels and inhibit cell proliferation.

    PubMed

    Alao, John P; Sunnerhagen, Per

    2009-11-10

    The ataxia telangiectasia mutated (ATM) and the ATM- related (ATR) kinases play a central role in facilitating the resistance of cancer cells to genotoxic treatment regimens. The components of the ATM and ATR regulated signaling pathways thus provide attractive pharmacological targets, since their inhibition enhances cellular sensitivity to chemo- and radiotherapy. Caffeine as well as more specific inhibitors of ATM (KU55933) or ATM and ATR (CGK733) have recently been shown to induce cell death in drug-induced senescent tumor cells. Addition of these agents to cancer cells previously rendered senescent by exposure to genotoxins suppressed the ATM mediated p21 expression required for the survival of these cells. The precise molecular pharmacology of these agents however, is not well characterized. Herein, we report that caffeine, CGK733, and to a lesser extent KU55933, inhibit the proliferation of otherwise untreated human cancer and non-transformed mouse fibroblast cell lines. Exposure of human cancer cell lines to caffeine and CGK733 was associated with a rapid decline in cyclin D1 protein levels and a reduction in the levels of both phosphorylated and total retinoblastoma protein (RB). Our studies suggest that observations based on the effects of these compounds on cell proliferation and survival must be interpreted with caution. The differential effects of caffeine/CGK733 and KU55933 on cyclin D1 protein levels suggest that these agents will exhibit dissimilar molecular pharmacological profiles.

  11. Activation of c-Myc and Cyclin D1 by JCV T-Antigen and β-Catenin in Colon Cancer

    PubMed Central

    Ripple, Michael J.; Parker Struckhoff, Amanda; Trillo-Tinoco, Jimena; Li, Li; Margolin, David A.; McGoey, Robin; Valle, Luis Del

    2014-01-01

    During the last decade, mounting evidence has implicated the human neurotropic virus JC virus in the pathology of colon cancer. However, the mechanisms of JC virus-mediated oncogenesis are still not fully determined. One candidate to mediate these effects is the viral early transcriptional product T-Antigen, which has the ability to inactivate cell cycle regulatory proteins such as p53. In medulloblastomas, T-Antigen has been shown to bind the Wnt signaling pathway protein β-catenin; however, the effects of this interaction on downstream cell cycle regulatory proteins remain unknown. In light of these observations, we investigated the association of T-Antigen and nuclear β-catenin in colon cancer cases and the effects of this complex in the activation of the transcription and cell cycle regulators c-Myc and Cyclin D1 in vitro. Gene amplification demonstrated the presence of viral sequences in 82.4% of cases and we detected expression of T-Antigen in 64.6% of cases by immunohistochemistry. Further, we found that T-Antigen and β-catenin co-localized in the nuclei of tumor cells and we confirmed the physical binding between these two proteins in vitro. The nuclear presence of T-Antigen and β-catenin resulted in the significant enhancement of TCF-dependent promoter activity and activation of the β-catenin downstream targets, c-Myc and Cyclin D1. These observations provide further evidence for a role of JCV T-Antigen in the dysregulation of the Wnt signaling pathway and in the pathogenesis of colon cancer. PMID:25229241

  12. X-linked inhibitor of apoptosis protein (XIAP) regulation of cyclin D1 protein expression and cancer cell anchorage-independent growth via its E3 ligase-mediated protein phosphatase 2A/c-Jun axis.

    PubMed

    Cao, Zipeng; Zhang, Ruowen; Li, Jingxia; Huang, Haishan; Zhang, Dongyun; Zhang, Jingjie; Gao, Jimin; Chen, Jingyuan; Huang, Chuanshu

    2013-07-12

    The X-linked inhibitor of apoptosis protein (XIAP) is a well known potent inhibitor of apoptosis; however, it is also involved in other cancer cell biological behavior. In the current study, we discovered that XIAP and its E3 ligase played a crucial role in regulation of cyclin D1 expression in cancer cells. We found that deficiency of XIAP expression resulted in a marked reduction in cyclin D1 expression. Consistently, cell cycle transition and anchorage-independent cell growth were also attenuated in XIAP-deficient cancer cells compared with those of the parental wild-type cells. Subsequent studies demonstrated that E3 ligase activity within the RING domain of XIAP is crucial for its ability to regulate cyclin D1 transcription, cell cycle transition, and anchorage-independent cell growth by up-regulating transactivation of c-Jun/AP-1. Moreover, we found that E3 ligase within RING domain was required for XIAP inhibition of phosphatase PP2A activity by up-regulation of PP2A phosphorylation at Tyr-307 in its catalytic subunit. Such PP2A phosphorylation and inactivation resulted in phosphorylation and activation of its downstream target c-Jun in turn leading to cyclin D1 expression. Collectively, our studies uncovered a novel function of E3 ligase activity of XIAP in the up-regulation of cyclin D1 expression, providing significant insight into the understanding of the biomedical significance of overexpressed XIAP in cancer development, further offering a new molecular basis for utilizing XIAP E3 ligase as a cancer therapeutic target.

  13. Cyclin D1 silencing suppresses tumorigenicity, impairs DNA double strand break repair and thus radiosensitizes androgen-independent prostate cancer cells to DNA damage.

    PubMed

    Marampon, Francesco; Gravina, Giovanni; Ju, Xiaoming; Vetuschi, Antonella; Sferra, Roberta; Casimiro, Mathew C; Pompili, Simona; Festuccia, Claudio; Colapietro, Alessandro; Gaudio, Eugenio; Di Cesare, Ernesto; Tombolini, Vincenzo; Pestell, Richard G

    2016-02-02

    Patients with hormone-resistant prostate cancer (PCa) have higher biochemical failure rates following radiation therapy (RT). Cyclin D1 deregulated expression in PCa is associated with a more aggressive disease: however its role in radioresistance has not been determined. Cyclin D1 levels in the androgen-independent PC3 and 22Rv1 PCa cells were stably inhibited by infecting with cyclin D1-shRNA. Tumorigenicity and radiosensitivity were investigated using in vitro and in vivo experimental assays. Cyclin D1 silencing interfered with PCa oncogenic phenotype by inducing growth arrest in the G1 phase of cell cycle and reducing soft agar colony formation, migration, invasion in vitro and tumor formation and neo-angiogenesis in vivo. Depletion of cyclin D1 significantly radiosensitizes PCa cells by increasing the RT-induced DNA damages by affecting the NHEJ and HR pathways responsible of the DNA double-strand break repair. Following treatment of cells with RT the abundance of a biomarker of DNA damage, γ-H2AX, was dramatically increased in sh-cyclin D1 treated cells compared to shRNA control. Concordant with these observations DNA-PKcs-activation and RAD51-accumulation, part of the DNA double-strand break repair machinery, were reduced in shRNA-cyclin D1 treated cells compared to shRNA control. We further demonstrate the physical interaction between CCND1 with activated-ATM, -DNA-PKcs and RAD51 is enhanced by RT. Finally, siRNA-mediated silencing experiments indicated DNA-PKcs and RAD51 are downstream targets of CCND1-mediated PCa cells radioresistance. In summary, these observations suggest that CCND1 is a key mediator of PCa radioresistance and could represent a potential target for radioresistant hormone-resistant PCa.

  14. Leptin-induced Growth Stimulation of Breast Cancer Cells Involves Recruitment of Histone Acetyltransferases and Mediator Complex to CYCLIN D1 Promoter via Activation of Stat3*

    PubMed Central

    Saxena, Neeraj K.; Vertino, Paula M.; Anania, Frank A.; Sharma, Dipali

    2010-01-01

    Numerous epidemiological studies documented that obesity is a risk factor for breast cancer development in postmenopausal women. Leptin, the key player in the regulation of energy balance and body weight control also acts as a growth factor on certain organs in both normal and disease state. In this study, we analyzed the role of leptin and the molecular mechanism(s) underlying its action in breast cancer cells that express both short and long isoforms of leptin receptor. Leptin increased MCF7 cell population in the S-phase of the cell cycle along with a robust increase in CYCLIN D1 expression. Also, leptin induced Stat3-phosphorylation-dependent proliferation of MCF7 cells as blocking Stat3 phosphorylation with a specific inhibitor, AG490, abolished leptin-induced proliferation. Using deletion constructs of CYCLIN D1 promoter and chromatin immunoprecipitation assay, we show that leptin induced increase in CYCLIN D1 promoter activity is mediated through binding of activated Stat3 at the Stat binding sites and changes in histone acetylation and methylation. We also show specific involvement of coactivator molecules, histone acetyltransferase SRC1, and mediator complex in leptin-mediated regulation of CYCLIN D1 promoter. Importantly, silencing of SRC1 and Med1 abolished the leptin induced increase in CYCLIN D1 expression and MCF7 cell proliferation. Intriguingly, recruitment of both SRC1 and Med1 was dependent on phosphorylated Stat3 as AG490 treatment inhibited leptin-induced recruitment of these coactivators to CYCLIN D1 promoter. Our data suggest that CYCLIN D1 may be a target gene for leptin mediated growth stimulation of breast cancer cells and molecular mechanisms involve activated Stat3-mediated recruitment of distinct coactivator complexes. PMID:17344214

  15. Cyclin D1 silencing suppresses tumorigenicity, impairs DNA double strand break repair and thus radiosensitizes androgen-independent prostate cancer cells to DNA damage

    PubMed Central

    Ju, Xiaoming; Vetuschi, Antonella; Sferra, Roberta; Casimiro, Mathew C.; Pompili, Simona; Festuccia, Claudio; Colapietro, Alessandro; Gaudio, Eugenio; Di Cesare, Ernesto; Tombolini, Vincenzo; Pestell, Richard G.

    2016-01-01

    Patients with hormone-resistant prostate cancer (PCa) have higher biochemical failure rates following radiation therapy (RT). Cyclin D1 deregulated expression in PCa is associated with a more aggressive disease: however its role in radioresistance has not been determined. Cyclin D1 levels in the androgen-independent PC3 and 22Rv1 PCa cells were stably inhibited by infecting with cyclin D1-shRNA. Tumorigenicity and radiosensitivity were investigated using in vitro and in vivo experimental assays. Cyclin D1 silencing interfered with PCa oncogenic phenotype by inducing growth arrest in the G1 phase of cell cycle and reducing soft agar colony formation, migration, invasion in vitro and tumor formation and neo-angiogenesis in vivo. Depletion of cyclin D1 significantly radiosensitizes PCa cells by increasing the RT-induced DNA damages by affecting the NHEJ and HR pathways responsible of the DNA double-strand break repair. Following treatment of cells with RT the abundance of a biomarker of DNA damage, γ-H2AX, was dramatically increased in sh-cyclin D1 treated cells compared to shRNA control. Concordant with these observations DNA-PKcs-activation and RAD51-accumulation, part of the DNA double-strand break repair machinery, were reduced in shRNA-cyclin D1 treated cells compared to shRNA control. We further demonstrate the physical interaction between CCND1 with activated-ATM, -DNA-PKcs and RAD51 is enhanced by RT. Finally, siRNA-mediated silencing experiments indicated DNA-PKcs and RAD51 are downstream targets of CCND1-mediated PCa cells radioresistance. In summary, these observations suggest that CCND1 is a key mediator of PCa radioresistance and could represent a potential target for radioresistant hormone-resistant PCa. PMID:26689991

  16. Role of p16/MTS1, cyclin D1 and RB in primary oral cancer and oral cancer cell lines

    PubMed Central

    Sartor, M; Steingrimsdottir, H; Elamin, F; Gäken, J; Warnakulasuriya, S; Partridge, M; Thakker, N; Johnson, N W; Tavassoli, M

    1999-01-01

    One of the most important components of G1 checkpoint is the retinoblastoma protein (pRB110). The activity of pRB is regulated by its phosphorylation, which is mediated by genes such as cyclin D1 and p16/MTS1. All three genes have been shown to be commonly altered in human malignancies. We have screened a panel of 26 oral squamous cell carcinomas (OSCC), nine premalignant and three normal oral tissue samples as well as eight established OSCC cell lines for mutations in the p16/MTS1 gene. The expression of p16/MTS1, cyclin D1 and pRB110 was also studied in the same panel. We have found p16/MTS1 gene alterations in 5/26 (19%) primary tumours and 6/8 (75%) cell lines. Two primary tumours and five OSCC cell lines had p16/MTS1 point mutations and another three primary and one OSCC cell line contained partial gene deletions. Six of seven p16/MTS1 point mutations resulted in termination codons and the remaining mutation caused a frameshift. Western blot analysis showed absence of p16/MTS1 expression in 18/26 (69%) OSCC, 7/9 (78%) premalignant lesions and 8/8 cell lines. One cell line, H314, contained a frameshift mutation possibly resulting in a truncated p16/MTS1 protein. pRB was detected in 14/25 (56%) of OSCC but only 11/14 (78%) of these contained all or some hypophosphorylated (active) pRB. In premalignant samples, 6/8 (75%) displayed pRB, and all three normal samples and eight cell lines analysed contained RB protein. p16/MTS1 protein was undetectable in 10/11 (91%) OSCCs with positive pRB. Overexpression of cyclin D1 was observed in 9/22 (41%) OSCC, 3/9 (33%) premalignant and 8/8 (100%) of OSCC cell lines. Our data suggest p16/MTS1 mutations and loss of expression to be very common in oral cancer cell lines and less frequent in primary OSCC tumours. A different pattern of p16/MTS1 mutations was observed in OSCC compared to other cancers with all the detected p16/MTS1 mutations resulting in premature termination codons or a frameshift. The RB protein was expressed

  17. Inhibition of the CyclinD1 promoter in response to sonic hedgehog signaling pathway transduction is mediated by Gli1

    PubMed Central

    Lin, Zhongxiao; Sheng, Hansong; You, Chaoguo; Cai, Ming; Zhang, Yiping; Yu, Li Sheng; Yu, Xiaoming; Lin, Jian; Zhang, Nu

    2017-01-01

    Medulloblastoma (MB) is the most common malignant tumor of the central nervous system in children. Accumulating evidence suggests a major role for the activation of the sonic hedgehog (SHH) signaling pathway in the development of MB cells; however, the mechanisms underlying the effect of this pathway on tumor survival and growth remain poorly understood. The Gli family zinc finger 1 (Gli1) transcription factor is considered as a mediator of the SHH signaling pathway in MB cells. Therefore, the present study investigated whether the SHH signaling pathway promotes the apoptosis of MB cells via downregulation of Gli1. GANT61, a novel Gli1 inhibitor, is known to have an in vitro activity against tumors. In the current study, Daoy cells were treated with different concentrations of GANT61 for 24 h, and the effect on cell proliferation was assayed by cell counting kit-8 assay. In addition, the cell cycle progression and apoptosis were assayed by flow cytometry analysis and hematoxylin-eosin (HE) staining. The effects of GANT61 treatment on SHH signaling pathway at the mRNA level were assayed by polymerase chain reaction (PCR). To further elucidate the inhibitory effects of GANT61 on the expression of Gli1 and CyclinD1, their protein levels were examined by western blot and immunofluorescence. The results indicated that GANT61 significantly inhibited the proliferation of Daoy cells in a dose-dependent manner, compared with the control group (P<0.05). HE staining revealed that cells had increasingly abnormal protuberance with increasing GANT61 concentration. Flow cytometry analysis also demonstrated that GANT61 induced G1/S arrest and apoptosis of Daoy cells in a dose-dependent manner (P<0.05). Gli1 and CyclinD1 mRNA expression levels were downregulated by GANT61 treatment (P<0.05); similarly, their protein levels were downregulated by GANT61 treatment in a dose-dependent manner (P<0.05). In conclusion, Gli1 expression was significantly associated with CyclinD1 expression

  18. Inhibition of the CyclinD1 promoter in response to sonic hedgehog signaling pathway transduction is mediated by Gli1.

    PubMed

    Lin, Zhongxiao; Sheng, Hansong; You, Chaoguo; Cai, Ming; Zhang, Yiping; Yu, Li Sheng; Yu, Xiaoming; Lin, Jian; Zhang, Nu

    2017-01-01

    Medulloblastoma (MB) is the most common malignant tumor of the central nervous system in children. Accumulating evidence suggests a major role for the activation of the sonic hedgehog (SHH) signaling pathway in the development of MB cells; however, the mechanisms underlying the effect of this pathway on tumor survival and growth remain poorly understood. The Gli family zinc finger 1 (Gli1) transcription factor is considered as a mediator of the SHH signaling pathway in MB cells. Therefore, the present study investigated whether the SHH signaling pathway promotes the apoptosis of MB cells via downregulation of Gli1. GANT61, a novel Gli1 inhibitor, is known to have an in vitro activity against tumors. In the current study, Daoy cells were treated with different concentrations of GANT61 for 24 h, and the effect on cell proliferation was assayed by cell counting kit-8 assay. In addition, the cell cycle progression and apoptosis were assayed by flow cytometry analysis and hematoxylin-eosin (HE) staining. The effects of GANT61 treatment on SHH signaling pathway at the mRNA level were assayed by polymerase chain reaction (PCR). To further elucidate the inhibitory effects of GANT61 on the expression of Gli1 and CyclinD1, their protein levels were examined by western blot and immunofluorescence. The results indicated that GANT61 significantly inhibited the proliferation of Daoy cells in a dose-dependent manner, compared with the control group (P<0.05). HE staining revealed that cells had increasingly abnormal protuberance with increasing GANT61 concentration. Flow cytometry analysis also demonstrated that GANT61 induced G1/S arrest and apoptosis of Daoy cells in a dose-dependent manner (P<0.05). Gli1 and CyclinD1 mRNA expression levels were downregulated by GANT61 treatment (P<0.05); similarly, their protein levels were downregulated by GANT61 treatment in a dose-dependent manner (P<0.05). In conclusion, Gli1 expression was significantly associated with CyclinD1 expression

  19. pRb and CyclinD1 Complement p16 as Immunohistochemical Surrogate Markers of HPV Infection in Head and Neck Cancer.

    PubMed

    Dreyer, Johannes H; Hauck, Franziska; Barros, Mário H M; Niedobitek, Gerald

    2015-12-09

    Identification of human papillomavirus (HPV) association in head and neck squamous cell carcinoma (HNSCC) is important to identify patients with favorable disease course. However, molecular HPV detection is not universally available. p16 has been proposed as a surrogate marker for HPV infection in HNSCC but, use on its own may result in wrong assignment of some cases to the group of HPV-associated tumors. We have therefore studied 424 HNSCC cases with known p16 and HPV DNA polymerase chain reaction (PCR) status for expression of retinoblastoma protein (pRb) and CyclinD1 by immunohistochemistry using 6-tiered scales (0 to 5) and a combined score (0 to 10). Sixty-one of 424 cases showed overexpression of p16. Of these, 52 cases were HPV DNA-PCR-positive. HPV association strongly correlated with low expression scores for pRb and CyclinD1 individually (scores ≤2) or combined (score sum ≤4), whereas HPV-negative carcinomas showed widely distributed expression scores. High expression scores for pRb or for pRb/CyclinD1 were observed exclusively in HPV DNA-PCR-negative cases. Three of 9 p16-positive/HPV DNA-PCR-negative cases showed high expression of pRb and displayed a high combined pRb/CyclinD1 score. We conclude that HPV-positive HNSCC are characterized by p16 overexpression and low scores for pRb, CyclinD1, and a low combined pRb/CyclinD1 score. High pRb or combined pRb/CyclinD1 scores are strong indicators for HPV-negativity and may justify excluding these cases from further molecular HPV testing. Furthermore p16-positive/HPV DNA-PCR-negative cases show heterogeneous expression of pRb and CyclinD1, including high pRb or high combined pRb/CyclinD1 scores suggesting that at least some of these cases are truly HPV negative.

  20. Immunohistochemical expression of the p53, mdm2, p21/Waf-1, Rb, p16, Ki67, cyclin D1, cyclin A and cyclin B1 proteins and apoptotic index in T-cell lymphomas.

    PubMed

    Kanavaros, P; Bai, M; Stefanaki, K; Poussias, G; Rontogianni, D; Zioga, E; Gorgoulis, V; Agnantis, N J

    2001-04-01

    Fifty-seven cases of T-cell lymphomas (TCL) including 5 lymphoblastic (T-LBL) and 52 peripheral TCL (PTCL) were analyzed by immunohistochemistry for the expression of p53, mdm2, p21, Rb, cyclin D1, cyclin A, cyclin B1, and Ki67/MIB1 proteins and 39/52 PTCL were also analyzed for the expression of p16 protein and for the presence of apoptotic cells by the TUNEL method. The aim was to search for abnormal immunoprofiles of p53 and Rb growth control pathways and to determine the proliferative activity and the apoptotic index of TCL. Abnormal overexpression of p53, p21 and mdm2, in comparison to normal lymph nodes, was found in 12/57, 10/57 and 2/57 cases of TCL, respectively. Abnormal loss of Rb and p16 expression was found in 1/57 and 2/39 cases, respectively, whereas abnormal overexpression of cyclin D1 was not detected in any of the 57 cases. Our data revealed entity-related p53/p21/mdm2 phenotypes. Indeed, most nodal and cutaneous CD30+ anaplastic large cell lymphomas (ALCL) showed concomitant overexpression of p53 and p21 proteins (7/8 cases), and mdm2 was overexpressed in 2 p53-positive nodal ALCL. In contrast, overexpression of p53 was found in 3/17 cases of nodal peripheral TCL unspecified (PTCL-UC) and 2/7 non-ALCL cutaneous pleomorphic TCL. Overexpression of p21 protein was detected in 2/3 p53-positive PTCL-UC and in 1/2 p53-positive non-ALCL cutaneous pleomorphic TCL. Finally, all the remaining 25 cases of TCL did not show p53 and p21 overexpression. Overall, the p53+/p21+ phenotype in 10/57 TCL suggests wild-type p53 capable of inducing p21 expression. The highest apoptotic index (AI) was found in ALCL and a positive correlation between apoptotic index and Ki67 index (p<0.001) was detected. Ki67, cyclin A and cyclin B1 expression was found in all 57 TCL and on the basis of the combined use of these 3 variables, 3 groups of proliferative activity could be determined: a) high in ALCL and T-LBL, b) low in mycosis fungoides (MF) and gammadelta hepatosplenic TCL

  1. Small interfering RNA (siRNA)-mediated knockdown of macrophage migration inhibitory factor (MIF) suppressed cyclin D1 expression and hepatocellular carcinoma cell proliferation.

    PubMed

    Huang, Xiao-Hui; Jian, Wei-Hua; Wu, Zhao-Feng; Zhao, Jie; Wang, Hua; Li, Wen; Xia, Jin-Tang

    2014-07-30

    Macrophage migration inhibitory factor (MIF), a proinflammatory and immunoregulatory chemokine, plays important roles in cancer-related biological processes. However, few studies have focused on the clinical relevance of MIF and cyclin D1 expression in hepatocellular carcinoma cells (HCCs). In this study, MIF and cyclin D1 expression levels in HCC tissues and cell lines were significantly upregulated compared with adjacent normal tissues or a normal liver cell line. In HCC specimens, MIF expression positively correlated with cyclin D1 expression. Additionally, MIF and cyclin D1 expression positively correlated with tumor size. MIF knockdown inhibited the proliferation of PLC and HepG2 cells and promoted apoptosis. However, small interfering RNA (siRNA) against MIF did not influence the cell cycle in these cells. In an in vivo xenograft model, MIF knockdown reduced the tumor growth rate. The expression levels of Bcl-2, p-caspase-3, BIM and Bax were upregulated, while the expression levels of cyclin D1, p-Akt and p-ERK were downregulated in MIF-knockdown cells. These findings indicate that MIF siRNA reduces proliferation and increases apoptosis in HCC cells. MIF knockdown inhibits the expression of growth-related proteins and induces the expression of apoptosis-related proteins, supporting a role for MIF as a novel therapeutic target for HCC.

  2. Early B-cell-specific inactivation of ATM synergizes with ectopic CyclinD1 expression to promote pre-germinal center B-cell lymphomas in mice.

    PubMed

    Yamamoto, K; Lee, B J; Li, C; Dubois, R L; Hobeika, E; Bhagat, G; Zha, S

    2015-06-01

    Ataxia telangiectasia-mutated (ATM) kinase is a master regulator of the DNA damage response. ATM is frequently inactivated in human B-cell non-Hodgkin lymphomas, including ~50% of mantle cell lymphomas (MCLs) characterized by ectopic expression of CyclinD1. Here we report that early and robust deletion of ATM in precursor/progenitor B cells causes cell autonomous, clonal mature B-cell lymphomas of both pre- and post-germinal center (GC) origins. Unexpectedly, naive B-cell-specific deletion of ATM is not sufficient to induce lymphomas in mice, highlighting the important tumor suppressor function of ATM in immature B cells. Although EμCyclinD1 is not sufficient to induce lymphomas, EμCyclinD1 accelerates the kinetics and increases the incidence of clonal lymphomas in ATM-deficient B-cells and skews the lymphomas toward pre-GC-derived small lymphocytic neoplasms, sharing morphological features of human MCL. This is in part due to CyclinD1-driven expansion of ATM-deficient naive B cells with genomic instability, which promotes the deletions of additional tumor suppressor genes (i.e. Trp53, Mll2, Rb1 and Cdkn2a). Together these findings define a synergistic function of ATM and CyclinD1 in pre-GC B-cell proliferation and lymphomagenesis and provide a prototypic animal model to study the pathogenesis of human MCL.

  3. Early B-cell Specific Inactivation of ATM Synergizes with Ectopic CyclinD1 Expression to Promote Pre-germinal center B-cell Lymphomas in Mice

    PubMed Central

    Yamamoto, Kenta; Lee, Brian J.; Li, Chen; Dubois, Richard L.; Hobeika, Elias; Bhagat, Govind; Zha, Shan

    2017-01-01

    Ataxia Telangiectasia Mutated (ATM) kinase is a master regulator of the DNA damage response. ATM is frequently inactivated in human B-cell non-Hodgkin Lymphomas (B-NHL), including ~50% of mantle cell lymphomas (MCLs) characterized by ectopic expression of CyclinD1. Here we report that early and robust deletion of ATM in precursor/progenitor B-cells causes cell-autonomous, clonal mature B cell lymphomas of both pre- and post-germinal center (GC) origins. Unexpectedly naïve B cell specific deletion of ATM is not sufficient to induce lymphomas in mice, highlighting the important tumor suppressor function of ATM in immature B cells. While EμCyclinD1 is not sufficient to induce lymphomas, EμCyclinD1 accelerates the kinetics and increased the incidence of clonal lymphomas in ATM-deficient B-cells and skews the lymphomas towards pre-GC derived small lymphocytic neoplasms sharing morphological features of human MCL. This is in part due to CyclinD1-driven expansion of ATM-deficient naïve B cells with genomic instability, which promotes the deletions of additional tumor suppressor genes (i.g. Trp53, Mll2, Rb1 and Cdkn2a). Together these findings define a synergistic function of ATM and CyclinD1 in pre-germinal center B-cell proliferation and lymphomagenesis and provide a prototypic animal model to study the pathogenesis of human MCL. PMID:25676421

  4. Peroxisome proliferator-activated receptor gamma agonists induce proteasome-dependent degradation of cyclin D1 and estrogen receptor alpha in MCF-7 breast cancer cells.

    PubMed

    Qin, Chunhua; Burghardt, Robert; Smith, Roger; Wormke, Mark; Stewart, Jessica; Safe, Stephen

    2003-03-01

    Treatment of MCF-7 cells with the peroxisome proliferator-activated receptor (PPAR) gamma agonists ciglitazone or 15-deoxy-Delta 12,14-prostaglandin J2 resulted in a concentration- and time-dependent decrease of cyclin D1 and estrogen receptor (ER) alpha proteins, and this was accompanied by decreased cell proliferation and G(1)-G(0)-->S-phase progression. Down-regulation of cyclin D1 and ER alpha by PPARgamma agonists was inhibited in cells cotreated with the proteasome inhibitors MG132 and PSII, but not in cells cotreated with the protease inhibitors calpain II and calpeptin. Moreover, after treatment of MCF-7 cells with 15-deoxy-Delta 12,14-prostaglandin J2 and immunoprecipitation with cyclin D1 or ER alpha antibodies, there was enhanced formation of ubiquitinated cyclin D1 and ER alpha bands. Thus, PPARgamma-induced inhibition of breast cancer cell growth is due, in part, to proteasome-dependent degradation of cyclin D1 (and ER alpha), and this pathway may be important for other cancer cell lines.

  5. Knockdown of ILK inhibits glioma development via upregulation of E-cadherin and downregulation of cyclin D1.

    PubMed

    Zheng, Kebin; Wang, Guangyi; Li, Chunhui; Shan, Xiaosong; Liu, Haipeng

    2015-07-01

    Integrin-linked kinase (ILK) is a highly conserved serine-threonine protein kinase that interacts with cytoplasmic domains of integrin subunits in tumor tissues. However, the relationship between gliomas and ILK is elusive. The present study aimed to investigate the role of ILK in a human glioma cell line (U251). ILK stable expressing vector, U251ILK-PGFP-V-RS-shRNA, was established and named as U251-si. The empty-PGFP-V-RS-shRNA (U251-N) was employed as the control. Quantitative real-time PCR and western blot analysis were used to detect ILK and E-cadherin mRNA and protein expression, respectively. Cell cycle analysis was employed to examine the cell cycle distribution. Cell migration was detected using a wound healing assay, and cell invasion was detected using a Transwell invasion assay. Tumor size and weight were also examined. The results indicated that ILK was expressed at a lower level at both the mRNA and protein levels in the U251-si group compared with the U251-N group (p<0.01). ILK knockdown suppressed cell proliferation of the glioma cells. Knockdown of ILK reduced the migratory and invasive potentials of the glioma cells. Inhibition of ILK expression upregulated E-cadherin and downregulated cyclin D1 in the glioma cells compared to the U251-N group (p<0.05). Knockdown of ILK in the U251 cells attenuated the ability of U251 cells to form tumors in nude mice and impaired glioma cell in vivo tumorigenicity. In conclusion, knockdown of ILK inhibits glioma cell migration, invasion and proliferation through upregulation of E-cadherin and downregulation of cyclin D1. Our results suggest that ILK may serve as a promising therapeutic target for glioma.

  6. The impact of cyclin D1 overexpression on the prognosis of ER-positive breast cancers: a meta-analysis.

    PubMed

    Xu, Xiao-Ling; Chen, Shu-Zheng; Chen, Wei; Zheng, Wei-Hui; Xia, Xiang-Hou; Yang, Hong-Jian; Li, Bo; Mao, Wei-Min

    2013-06-01

    Cyclin D1 (CCND1), a key regulator of cell cycle progression, is overexpressed in many human cancers, including breast cancer. However, the impact of CCND1 overexpression in these cancers remains unclear and controversial. We conducted a systematic literature search in PubMed and EMBASE with the search terms "cyclin D1", "CCND1", "breast cancer", "prognosis", and potential studies for analysis were selected. Studies with survival data, including progression-free survival (PFS), overall survival (OS) or metastasis-free survival (MFS), were included in this meta-analysis. A total of 33 studies containing 8,537 cases were included. The combined hazard risk (HR) and its 95 % confidence interval (CI) of OS, PFS and MFS were 1.13 (95 % CI 0.87-1.47; P = 0.35), 1.25 (95 % CI 0.95-1.64; P = 0.12), and 1.04 (95 % CI 0.80-1.36; P = 0.76), respectively, for primary breast cancer patients with tumors exhibiting CCND1 overexpression. Interestingly, the impact of CCND1 expression on OS was a 1.67-fold (95 % CI 1.38-2.02; P = 0.00) increased risk for ER-positive breast cancer patients. However, CCND1 overexpression exhibited no association with the PFS or OS of patients who received epirubicin-based neoadjuvant chemotherapy, for which the P values were 0.63 and 0.47, respectively. In summary, CCND1 overexpression impacts the prognosis of ER-positive breast cancer patients, but not patients with unselected primary breast cancer or patients treated with neoadjuvant chemotherapy.

  7. The ω-3 epoxide of eicosapentaenoic acid inhibits endothelial cell proliferation by p38 MAP kinase activation and cyclin D1/CDK4 down-regulation

    PubMed Central

    Cui, Pei H; Petrovic, Nenad; Murray, Michael

    2011-01-01

    BACKGROUND AND PURPOSE Dietary intake of ω-3 polyunsaturated fatty acids (ω-3 PUFAs) like eicosapentaenoic acid (EPA) decreases cancer risk, while arachidonic acid and other ω-6 PUFAs increase risk, but the underlying mechanisms are unclear. Cytochrome P450 (CYP)-derived epoxides contribute to enhanced tumourigenesis due to ω-6 PUFA intake. Thus, ω-6 arachidonic acid epoxides (EETs) inhibit apoptosis and stimulate proliferation by up-regulating cyclin D1 expression in cells. The present study evaluated the corresponding ω-3 PUFA epoxides and assessed their role in the regulation of cell proliferation. EXPERIMENTAL APPROACH Four chemically stable EPA epoxides (formed at the 8,9-, 11,12-, 14,15- and 17,18-olefinic bonds) were synthesized and tested against growth-related signalling pathways in brain microvascular endothelial bEND.3 cells. Cell cycle distribution was determined by flow cytometry and cyclin gene expression by immunoblotting and real-time PCR. The role of the p38 mitogen-activated protein (MAP) kinase in cyclin D1 dysregulation was assessed using specific inhibitors and dominant-negative expression plasmids. KEY RESULTS The ω-3 17,18-epoxide of EPA decreased cell proliferation, interrupted the cell cycle in S-phase and down-regulated the cyclin D1/cyclin-dependent kinase (CDK)-4 complex, whereas the 8,9-, 11,12- and 14,15-epoxides were either inactive or enhanced proliferation. Cyclin D1 down-regulation by 17,18-epoxy-EPA was mediated by activation of the growth-suppressing p38 MAP kinase, but the alternate EPA-epoxides were inactive. CONCLUSIONS AND IMPLICATIONS The present findings suggest that the epoxide formed by CYP enzymes at the ω-3 olefinic bond may contribute to the beneficial effects of ω-3 PUFA by down-regulating cyclin D1 and suppressing cell proliferation. PMID:21077851

  8. Notch1-induced mammary tumor development is cyclin D1-dependent and correlates with expansion of pre-malignant multipotent duct-limited progenitors.

    PubMed

    Ling, H; Sylvestre, J-R; Jolicoeur, P

    2010-08-12

    Members of the Notch family are involved in the development of breast cancer in animal models and in humans. In young transgenic mice, expressing intracellular activated Notch1 (N1(IC)) in mammary cells, we found that CD24(+) CD29(high) progenitor cells had enhanced survival, and were expanded through a cyclin D1-dependent pathway. This expansion positively correlated with the later cyclin D1-dependent formation of basal-like ductal tumors. This expanded population exhibited abnormal differentiation skewed toward the basal cells, showed signs of pre-malignancy (low PTEN/p53 and high c-myc) and contained stem cells with impaired self-renewal in vivo, and more numerous multipotent, ductal-restricted progenitors. Our data suggest that N1(IC) can favor transformation of progenitor cells early in life through a cyclin D1-dependent pathway.

  9. Differentiation-inducing factor-1 induces cyclin D1 degradation through the phosphorylation of Thr{sup 286} in squamous cell carcinoma

    SciTech Connect

    Mori, Jun; Takahashi-Yanaga, Fumi . E-mail: yanaga@clipharm.med.kyushu-u.ac.jp; Miwa, Yoshikazu; Watanabe, Yutaka; Hirata, Masato; Morimoto, Sachio; Shirasuna, Kanemitsu; Sasaguri, Toshiyuki

    2005-11-01

    Differentiation-inducing factors (DIFs) are morphogens which induce cell differentiation in Dictyostelium. We reported that DIF-1 and DIF-3 inhibit proliferation and induce differentiation in mammalian cells. In this study, we investigated the effect of DIF-1 on oral squamous cell carcinoma cell lines NA and SAS, well differentiated and poorly differentiated cell lines, respectively. Although DIF-1 did not induce the expression of cell differentiation makers in these cell lines, it inhibited the proliferation of NA and SAS in a dose-dependent manner by restricting the cell cycle in the G{sub 0}/G{sub 1} phase. DIF-1 induced cyclin D1 degradation, but this effect was prevented by treatment with lithium chloride and SB216763, the inhibitors of glycogen synthase kinase-3{beta} (GSK-3{beta}). Depletion of endogenous GSK-3{beta} by RNA interference also attenuated the effect of DIF-1 on cyclin D1 degradation. Therefore, we investigated the effect of DIF-1 on GSK-3{beta} and found that DIF-1 dephosphorylated GSK-3{beta} on Ser{sup 9} and induced the nuclear translocation of GSK-3{beta}, suggesting that DIF-1 activated GSK-3{beta}. Then, we examined the effect of DIF-1 on cyclin D1 mutants (Thr286Ala, Thr288Ala, and Thr286/288Ala). We revealed that Thr286Ala and Thr286/288Ala mutants were highly resistant to DIF-1-induced degradation compared with wild-type cyclin D1, indicating that the phosphorylation of Thr{sup 286} was critical for cyclin D1 degradation induced by DIF-1. These results suggest that DIF-1 induces degradation of cyclin D1 through the GSK-3{beta}-mediated phosphorylation of Thr{sup 286}.

  10. Effects of MEK and DNMT inhibitors on arsenic-treated human uroepithelial cells in relation to Cyclin-D1 and p16.

    PubMed

    Huang, Ya-Chun; Hung, Wen-Chun; Chen, Wan-Tzu; Jiang, Wen-Hong; Yu, Hsin-Su; Chai, Chee-Yin

    2011-01-15

    Arsenic compounds are well-known toxic and carcinogenic agents, and they are widely distributed throughout the earth's crust. These compounds are associated with various human malignancies. It has been reported that there is an elevated risk of bladder cancer in an area highly contaminated with arsenic on the southwest coast of Taiwan. However, the underlying mechanisms of arsenic-associated carcinogenesis are still unclear. The cell cycle regulatory proteins are important indicators in control of cell cycle progression. Moreover, the high expression of Cyclin-D1 and loss of p16 has been associated with a worse prognosis in a variety of human cancers. Therefore, we investigated the effect of arsenic on Cyclin-D1 and p16 expression and evaluated the role of the ERK signaling pathway and DNA methylation in arsenic carcinogenesis. Our study results showed that Cyclin-D1 high expression was found in 56.3% (9/16) of urothelial carcinomas (UC) from a blackfoot disease (BFD) area and 6.3% (1/16) of UC from a non-BFD area (p=0.002). The p16 low expression in 81.2% (13/16) of UC from BFD areas was significantly lower than in non-BFD areas (25.0%; 4/16) (p=0.001). In addition, the Cyclin-D1 increased expression but decreased p16 expression in arsenite-treated SV-HUC-1 cells. However, when cells were pretreated with inhibitors (5-aza-CdR or U0126), the effects of arsenite on Cyclin-D1 and p16 expression were suppressed. Finally, these results indicated that Cyclin-D1 and p16 both might play important roles in carcinogenesis as a result of arsenic. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  11. Expression pattern of ATM and cyclin D1 in ductal carcinoma, normal adjacent and normal breast tissues of Iranian breast cancer patients.

    PubMed

    Salimi, Mahdieh; Mozdarani, Hossein; Majidzadeh, Keivan

    2012-09-01

    ATM protein kinase plays a critical role in maintaining genome integrity by activating a biochemical chain reaction that in turn leads to cell cycle checkpoint activation and repair of DNA damage. Cyclin D1 acts in regulating the G1 phase of the cell cycle. Experimental and clinical studies suggest them to be involved in transformation and tumour progression. To elucidate the role of ATM and cyclin D1 expression in sporadic breast cancer, we investigated the possible link between their RNA expression levels in ductal carcinoma and normal adjacent versus normal breast tissues measured by Taqman real-time PCR in 119 breast tissues. Results showed that cyclin D1 over-expressed in 51.4% of breast tumours, whereas ATM expression was down regulated in 55% of breast tumours compared to both normal adjacent and normal controls (P ≤ 0.01). Cyclin D1 expression in adjacent normal and normal tissues was not significantly differed, whereas ATM expression in normal adjacent was lower than normal control (P ≤ 0.01). Over-expression of cyclin D1 correlated with ER(+) and/or PR(+) (oestrogen/progesterone receptor) status, whereas it mostly under-expressed in HER2(+) (human epidermal growth factor 2) tumours. ATM under-expression was more observed in triple-negative tumours (ER(-), PR(-) and HER2(-)). Our results indicated that reduced expression of the ATM and aberrant cyclin D1 expressions may contribute to the development and/or malignant progression of breast carcinomas also the latter could be involved in the regulation of hormone sensitivity associated with ER and PR.

  12. 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.

  13. [Expression of CD68, cyclin D1 and rearrangement of bcl-6 gene are adverse prognostic factors in diffuse large B-cell lymphoma].

    PubMed

    Liang, Xiaojie; Wang, Jinfen; Bai, Wei; Sun, Ruifang

    2015-08-01

    To study expression of CD68, cyclin D1 protein and rearrangement of bcl-6 gene impact on the prognosis of diffuse large B-cell lymphoma (DLBCL). Gets paraffin samples of the 105 cases DLBCL with the detailed follow-up information, and were studied by using immunohistochemical EnVision method for CD3, CD10, CD20, CD68, cyclin D1, bcl-6, MUM 1, SOX-11 immunolabeling. The DLBCL were classified into germinal center B cell-like (GCB) subtypes and non-germinal center B cell-like (non-GCB) subtypes according to Hans'algorithm. Application of fluorescence in situ hybridization (FISH) technique to detect the bcl-6 gene rearrangement. The relationship between CD68, cyclin D1 protein, the bcl-6 gene and the curative effect of chemotherapy and survival was analyzed using statistical software. Respectively by GCB type, non-GCB type immune phenotype and CHOP, R-CHOP chemotherapy group, compare the curative effects. 105 patients had GCB 19 cases (18.1%), non-GCB 86 cases (81.9%), CD68 expression was 18 cases (17.1%), cyclin D1 high expression 36 cases (34.3%), bcl-6 gene rearrangement in 21 cases (21.9%), there is no correlation among the three (P > 0.05). One-way analysis of variance showed that age ≤ 60 years, clinical stage I-II, IPI score 0 to 2 points, LDH (U/L) < 245 IU/L,GCB subtypes, R-CHOP therapy, the prognosis of patients with better (P < 0.05), But gender, primary site no correlation with prognosis (P > 0.05). CD68, cyclin D1 high expression, bcl-6 rearrangement had poor prognosis (P < 0.05). Stratification analysis results show GCB-type or non-GCB type with high expression of CD68 contrast alloimmune phenotype groups had a poor prognosis, non-GCB type with high expression of cyclin D1 and rearrangement of bcl-6 gene had a poor prognosis (P < 0.001, P = 0.02). Treatment scheme of layered display, the CHOP treatment, significantly correlated with overall survival with high expression of CD68, cyclin D1 (P < 0.05), the R-CHOP treatment, there was no statistically

  14. Role of cyclin D1 as a mediator of c-Met- and beta-catenin-induced hepatocarcinogenesis.

    PubMed

    Patil, Mohini A; Lee, Susie A; Macias, Everardo; Lam, Ernest T; Xu, Chuanrui; Jones, Kirk D; Ho, Coral; Rodriguez-Puebla, Marcelo; Chen, Xin

    2009-01-01

    Activation of c-Met signaling and beta-catenin mutations are frequent genetic events observed in liver cancer development. Recently, we demonstrated that activated beta-catenin can cooperate with c-Met to induce liver cancer formation in a mouse model. Cyclin D1 (CCND1) is an important cell cycle regulator that is considered to be a downstream target of beta-catenin. To determine the importance of CCND1 as a mediator of c-Met- and beta-catenin-induced hepatocarcinogenesis, we investigated the genetic interactions between CCND1, beta-catenin, and c-Met in liver cancer development using mouse models. We coexpressed CCND1 with c-Met in mice and found CCND1 to cooperate with c-Met to promote liver cancer formation. Tumors induced by CCND1/c-Met had a longer latency period, formed at a lower frequency, and seemed to be more benign compared with those induced by beta-catenin/c-Met. In addition, when activated beta-catenin and c-Met were coinjected into CCND1-null mice, liver tumors developed despite the absence of CCND1. Intriguingly, we observed a moderate accelerated tumor growth and increased tumor malignancy in these CCND1-null mice. Molecular analysis showed an up-regulation of cyclin D2 (CCND2) expression in CCND1-null tumor samples, indicating that CCND2 may replace CCND1 in hepatic tumorigenesis. Together, our results suggest that CCND1 functions as a mediator of beta-catenin during HCC pathogenesis, although other molecules may be required to fully propagate beta-catenin signaling. Moreover, our data suggest that CCND1 expression is not essential for liver tumor development induced by c-Met and beta-catenin.

  15. 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.

  16. CCN2 promotes cigarette smoke-induced proliferation of rat pulmonary artery smooth muscle cells through upregulating cyclin D1 expression.

    PubMed

    Wang, Ran; Xu, Yong-jian; Liu, Xian-sheng; Zeng, Da-xiong; Xiang, Min

    2012-01-01

    Cigarette smoke has been demonstrated to induce pulmonary vascular remodeling, which is characterized by medial thickening of the pulmonary arteries mainly resulting from the abnormal proliferation of pulmonary artery smooth muscle cells (PASMCs). However, the molecular mechanism underlying this process is still unclear. In the present study, we investigated whether CCN2 regulated rat PASMCs (rPASMCs) proliferation induced by cigarette smoke extract (CSE) and nicotine by upregulating cyclin D1 in vitro. CCN2 siRNA or cyclin D1 siRNA were transfected to rPASMCs which were then exposed to CSE and nicotine. Both mRNA and protein expressions of CCN2 were significantly increased in rPASMCs treated with 2% CSE or 1 µM nicotine, which markedly promoted the proliferation of rPASMCs. CCN2 siRNA inhibited the proliferation of rPASMCs induced by CSE or nicotine. Furthermore, CCN2 siRNA markedly suppressed the mRNA and protein expressions of cyclin D1 in rPASMCs and led to cell cycle arrest in G0/G1 phase resulting in reduced rPASMCs proliferation. These findings suggest that CCN2 contributes to the CSE and nicotine-induced proliferation of rPASMCs at least in part by upregulating cyclin D1 expression. Copyright © 2011 Wiley Periodicals, Inc.

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

    SciTech Connect

    Cheng, Ya-Hsin; Li, Lih-Ann; Lin, Pinpin; Cheng, Li-Chuan; Hung, Chein-Hui; Chang, Nai Wen; Lin, Chingju

    2012-09-15

    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 phase 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.

  18. The novel agent phospho-glycerol-ibuprofen-amide (MDC-330) inhibits glioblastoma growth in mice: an effect mediated by cyclin D1.

    PubMed

    Bartels, Lauren E; Mattheolabakis, George; Vaeth, Brandon M; LaComb, Joseph F; Wang, Ruixue; Zhi, Jizu; Komninou, Despina; Rigas, Basil; Mackenzie, Gerardo G

    2016-04-01

    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.

  19. 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

  20. Differential expression of p16(INK4A) and cyclin D1 in benign and malignant salivary gland tumors: a study of 44 Cases.

    PubMed

    Jour, G; West, K; Ghali, V; Shank, D; Ephrem, G; Wenig, B M

    2013-09-01

    Salivary gland tumors (SGT) are a heterogeneous group of lesions. There is conflicting data concerning the molecular events involving the tumour suppressor retinoblastoma protein (pRb) pathway in these tumors. Few studies examined the alterations in components of the Rb pathway by immunohistochemical (IHC) methods in benign and malignant SGTs. Furthermore, recent evidence implicates human papillomavirus (HPV) in mucoepidermoid carcinoma (MEC) carcinogenesis. The purpose of our study is to examine p16(INK4A) and cyclin D1 expression in a variety of benign and malignant salivary gland tumors, and to investigate p16(INK4A) expression as a surrogate marker for HPV infection in MEC. Our series includes 30 malignant tumors [14 MEC, 6 acinic cell carcinomas (ACC), 5 polymorphous low grade adenocarcinomas (PLGA), 5 (AdCC)] and 14 benign tumors (4 benign cysts, 5 Warthin tumors and 5 pleomorphic adenomas (PA). All cases were tested by IHC for p16(INK4A) and cyclin D1. Testing for HPV wide spectrum (HPV-WS) was performed by in situ hybridization in all MEC cases. Staining intensity was recorded semi quantitatively (on a scale from 0 to 4+). Fisher's exact test and Pearson X2 test with a p < 0.05 were used. Cyclin D1 and p16(INK4A) are expressed similarly in malignant and benign tumors (p = 0.146 and p = 0.543, respectively). None of the MEC cases showed nuclear reactivity for HPV-WS. Statistical analysis showed positive correlation between cyclin D1 and p16(INK4A) expression. Our findings suggest that p16(INK4A) overexpression is likely secondary to cyclin D1 gene upregulation or amplification. Further molecular studies are warranted.

  1. Immunohistochemical evaluation of oral epithelial dysplasia using cyclin-D1, p27 and p63 expression as predictors of malignant transformation.

    PubMed

    Ramasubramanian, Abilasha; Ramani, Pratibha; Sherlin, Herald J; Premkumar, Priya; Natesan, Anuja; Thiruvengadam, Chandrasekar

    2013-07-01

    To evaluate the degree of expression of cyclin-D1, p27 and p63 in mild, moderate and severe dysplasia using immunohistochemical evaluation in order to illustrate their prognostic value and attempt to propose a molecular grading system for oral epithelial dysplasia. The analysis included thirty cases of mild, moderate and severe dysplasia from Department of Oral and Maxillofacial Pathology, Saveetha Dental College, Chennai after a critical review of the Hematoxylin and Eosin (H and E) stained sections. They were subjected to immunohistochemical evaluation using the markers cyclin-D1, p27 and p63. The assessment of the expression based on staining intensity and distribution of immunohistochemical staining of the various markers was analyzed followed by statistical analysis. A highly significant increase in the expression of cyclin-D1 (P < 0.000) and p63 (P < 0.001) and a moderately significant decrease in the expression of p27 (P < 0.012) with the increasing severity of dysplasia was observed in our study. The result of our research affirms the fact that the increase in the expression of markers of cell cycle regulators such as cyclin D1, decrease in the expression of cell cycle inhibitors like p27 and increased expression of p63 in parallel with the increasing severity of dysplasia, emphasizes the use of immunohistochemical markers cyclin D1, p27 and p63 as prognostic markers for better understanding the behaviour of these potentially malignant disorders aiming towards proposing a molecular grading system for oral epithelial dysplasia to enable timely management prior to their possible malignant transformation.

  2. Immunohistochemical evaluation of oral epithelial dysplasia using cyclin-D1, p27 and p63 expression as predictors of malignant transformation

    PubMed Central

    Ramasubramanian, Abilasha; Ramani, Pratibha; Sherlin, Herald J.; Premkumar, Priya; Natesan, Anuja; Thiruvengadam, Chandrasekar

    2013-01-01

    Objective: To evaluate the degree of expression of cyclin-D1, p27 and p63 in mild, moderate and severe dysplasia using immunohistochemical evaluation in order to illustrate their prognostic value and attempt to propose a molecular grading system for oral epithelial dysplasia. Materials and Methods: The analysis included thirty cases of mild, moderate and severe dysplasia from Department of Oral and Maxillofacial Pathology, Saveetha Dental College, Chennai after a critical review of the Hematoxylin and Eosin (H and E) stained sections. They were subjected to immunohistochemical evaluation using the markers cyclin-D1, p27 and p63. The assessment of the expression based on staining intensity and distribution of immunohistochemical staining of the various markers was analyzed followed by statistical analysis. Results: A highly significant increase in the expression of cyclin-D1 (P < 0.000) and p63 (P < 0.001) and a moderately significant decrease in the expression of p27 (P < 0.012) with the increasing severity of dysplasia was observed in our study. Conclusions: The result of our research affirms the fact that the increase in the expression of markers of cell cycle regulators such as cyclin D1, decrease in the expression of cell cycle inhibitors like p27 and increased expression of p63 in parallel with the increasing severity of dysplasia, emphasizes the use of immunohistochemical markers cyclin D1, p27 and p63 as prognostic markers for better understanding the behaviour of these potentially malignant disorders aiming towards proposing a molecular grading system for oral epithelial dysplasia to enable timely management prior to their possible malignant transformation. PMID:24082731

  3. Betulinic acid decreases expression of bcl-2 and cyclin D1, inhibits proliferation, migration and induces apoptosis in cancer cells.

    PubMed

    Rzeski, Wojciech; Stepulak, Andrzej; Szymański, Marek; Sifringer, Marco; Kaczor, Józef; Wejksza, Katarzyna; Zdzisińska, Barbara; Kandefer-Szerszeń, Martyna

    2006-10-01

    Betulinic acid (BA) is a pentacyclic triterpene found in many plant species, among others in the bark of white birch Betula alba. BA was reported to display a wide range of biological effects, including antiviral, antiparasitic, antibacterial and anti-inflammatory activities, and in particular to inhibit growth of cancer cells. The aim of the study was further in vitro characterization of BA anticancer activity. In this study, we demonstrated a remarkable antiproliferative effect of BA in all tested tumor cell cultures including neuroblastoma, rabdomyosarcoma-medulloblastoma, glioma, thyroid, breast, lung and colon carcinoma, leukemia and multiple myeloma, as well as in primary cultures isolated from ovarian carcinoma, cervical carcinoma and glioblastoma multiforme. Furthermore, we have shown that BA decreased cancer cell motility and induced apoptotic cell death. We also observed decrease of bcl2 and cyclin D1 genes expression, and increase of bax gene expression after betulinic acid treatment. These findings demonstrate the anticancer potential of betulinic acid and suggest that it may be taken into account as a supportive agent in the treatment of cancers with different tissue origin.

  4. 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

  5. Colocalization of β-catenin with Notch intracellular domain in colon cancer: a possible role of Notch1 signaling in activation of CyclinD1-mediated cell proliferation.

    PubMed

    Gopalakrishnan, Natarajan; Saravanakumar, Marimuthu; Madankumar, Perumal; Thiyagu, Mani; Devaraj, Halagowder

    2014-11-01

    The Wnt and Notch1 signaling pathways play major roles in intestinal development and tumorigenesis. Sub-cellular localization of β-catenin has been implicated in colorectal carcinogenesis. However, the β-catenin and Notch intracellular domain (NICD) interaction has to be addressed. Immunohistochemistries of β-catenin, NICD, and dual immunofluorescence of β-catenin and NICD were analyzed in colorectal tissues and HT29 cell line. Moreover, real-time PCR analysis of CyclinD1, Hes1 and MUC2 was done in HT29 cells upon N-[N-(3, 5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT) treatment. Dual staining emphasized the strong interaction of β-catenin and NICD in adenoma and adenocarcinoma than in normal tissues. Hes1 transcript levels were decreased 1.5- and 7.1-fold in 12.5 and 25 µM DAPT-treated HT29 cells. CyclinD1 transcript levels decreased 1.2- and 1.6-fold, and MUC2 transcript level increased 4.3- and 7.5-fold in 12.5 and 25 µM DAPT-treated HT29 cells. The results of this study showed that the sub-cellular localization of β-catenin converges with NICD inducing proliferation through the activation of CyclinD1 and Hes1. Moreover, the inhibition of Notch1 signaling by DAPT leads to the arrest of cell proliferation and induces apoptosis leading to the upregulation of MUC2, a secretory cell lineage marker.

  6. NFAT1 transcription factor regulates cell cycle progression and cyclin E expression in B lymphocytes.

    PubMed

    Teixeira, Leonardo K; Carrossini, Nina; Sécca, Cristiane; Kroll, José E; DaCunha, Déborah C; Faget, Douglas V; Carvalho, Lilian D S; de Souza, Sandro J; Viola, João P B

    2016-09-01

    The NFAT family of transcription factors has been primarily related to T cell development, activation, and differentiation. Further studies have shown that these ubiquitous proteins are observed in many cell types inside and outside the immune system, and are involved in several biological processes, including tumor growth, angiogenesis, and invasiveness. However, the specific role of the NFAT1 family member in naive B cell proliferation remains elusive. Here, we demonstrate that NFAT1 transcription factor controls Cyclin E expression, cell proliferation, and tumor growth in vivo. Specifically, we show that inducible expression of NFAT1 inhibits cell cycle progression, reduces colony formation, and controls tumor growth in nude mice. We also demonstrate that NFAT1-deficient naive B lymphocytes show a hyperproliferative phenotype and high levels of Cyclin E1 and E2 upon BCR stimulation when compared to wild-type B lymphocytes. NFAT1 transcription factor directly regulates Cyclin E expression in B cells, inhibiting the G1/S cell cycle phase transition. Bioinformatics analysis indicates that low levels of NFAT1 correlate with high expression of Cyclin E1 in different human cancers, including Diffuse Large B-cell Lymphomas (DLBCL). Together, our results demonstrate a repressor role for NFAT1 in cell cycle progression and Cyclin E expression in B lymphocytes, and suggest a potential function for NFAT1 protein in B cell malignancies.

  7. Overexpression of Reg3alpha increases cell growth and the levels of cyclin D1 and CDK4 in insulinoma cells.

    PubMed

    Cui, Wei; De Jesus, Kristine; Zhao, Hong; Takasawa, Shin; Shi, Bingyin; Srikant, Coimbatore B; Liu, Jun-Li

    2009-06-01

    Regenerating gene (Reg) family protein Reg3alpha is normally expressed in pancreatic acinar and endocrine cells. In order to explore its effect on islet beta-cell replication, insulinoma MIN6 cells were stably transfected with murine Reg3alpha cDNA. Determined using real-time PCR and Western blots, the levels of Reg3alpha mRNA and protein in Reg3alpha-transfected clones were increased 10- and 6-fold, respectively. Western blots also revealed that the protein was released into the culture medium, consistent with an endocrine effect. In MTT cell proliferation assay, Reg3alpha-overexpressing cells exhibited a 2-fold increase in the rate of cell growth. In order to investigate the intracellular mechanism, we studied cell cycle regulatory proteins. In Reg3alpha-expressing cells, we detected 2.2- and 2.5-fold increased levels of cyclin D1 and CDK4, respectively, which paralleled a 1.8-fold increase in the rate of Akt phosphorylation. It is established that beta-cell replication is associated with increased cyclin D1 and CDK4 levels; deficiency in CDK4 or cyclin D2 results in reduced beta-cell mass and diabetes. Our results suggest that Reg3alpha stimulates beta-cell replication, by activating Akt kinase and increasing the levels of cyclin D1/CDK4.

  8. Disruption of transforming growth factor-beta signaling through beta-spectrin ELF leads to hepatocellular cancer through cyclin D1 activation.

    PubMed

    Kitisin, K; Ganesan, N; Tang, Y; Jogunoori, W; Volpe, E A; Kim, S S; Katuri, V; Kallakury, B; Pishvaian, M; Albanese, C; Mendelson, J; Zasloff, M; Rashid, A; Fishbein, T; Evans, S R T; Sidawy, A; Reddy, E P; Mishra, B; Johnson, L B; Shetty, K; Mishra, L

    2007-11-01

    Transforming growth factor-beta (TGF-beta) signaling members, TGF-beta receptor type II (TBRII), Smad2, Smad4 and Smad adaptor, embryonic liver fodrin (ELF), are prominent tumor suppressors in gastrointestinal cancers. Here, we show that 40% of elf(+/-) mice spontaneously develop hepatocellular cancer (HCC) with markedly increased cyclin D1, cyclin-dependent kinase 4 (Cdk4), c-Myc and MDM2 expression. Reduced ELF but not TBRII, or Smad4 was observed in 8 of 9 human HCCs (P<0.017). ELF and TBRII are also markedly decreased in human HCC cell lines SNU-398 and SNU-475. Restoration of ELF and TBRII in SNU-398 cells markedly decreases cyclin D1 as well as hyperphosphorylated-retinoblastoma (hyperphosphorylated-pRb). Thus, we show that TGF-beta signaling and Smad adaptor ELF suppress human hepatocarcinogenesis, potentially through cyclin D1 deregulation. Loss of ELF could serve as a primary event in progression toward a fully transformed phenotype and could hold promise for new therapeutic approaches in human HCCs.

  9. Curcumol induces cell cycle arrest in colon cancer cells via reactive oxygen species and Akt/ GSK3β/cyclin D1 pathway.

    PubMed

    Wang, Juan; Li, Xu-Mei; Bai, Zhun; Chi, Bi-Xia; Wei, Yan; Chen, Xu

    2017-07-04

    Curcuma kwangsiensis S. G. Lee & C. F. Liang (Guangxi ezhu, in Chinese) belongs to the Zingiberaceae family, has been used as a traditionally Chinese medicine nearly 2000 year. Curcumol is one of the guaiane-type sesquiterpenoid hemiketal isolated from medicine plant Curcuma kwangsiensis S. G. Lee & C. F. Liang, which has been reported possesses anti-cancer effects. Our previous study found that the most contribution to inhibit nasopharyngeal carcinoma cell growth was curcumol. To assess the effect of curcumol on cell cycle arrest against human colon cancer cells (CRC) cells (LoVo and SW480) and explore its mechanism in vitro and in vivo. Curcumol was dissolved in absolute ethyl alcohol. The concentration of absolute ethyl alcohol in the control group or in experimental samples was always 1/500 (v/v) of the final medium volume. LoVo and SW480 cells were treated with different concentrations of curcumol (0, 53, 106, 212 and 424μM). And then the cell cycle of each group was examined by flow cytometry. The protein levels of PI3K, p-Akt, cyclin D1, cyclin E, CDK2, CDK4 and GSK3β were determined by Western blot. The mRNA expression of PI3K, Akt, cyclin D1, CDK4, P27, p21, and P16 in the treated cells were analyzed by real-time RT-PCR. In addition, the antitumor activity of curcumol was evaluated in nude mice bearing orthotopic tumor implants. Curcumol induced cell cycle arrest in G1/S phase. RT-qPCR and Western blot data showed that curcumol enhanced the expression of GSK3β, P27, p21 and P16, and decreased the levels of PI3K, phosphorylated Akt (p-Akt), cyclin D1, CDK4, cyclin E and CDK2. Furthermore, curcumol induced reactive oxygen species (ROS) generation in LoVo cells, and ROS scavenger N-acetylcysteine (NAC) significantly reversed curcumol-induced cell growth inhibition. Besides, curcumol also prevented the growth of human colon cancer cells xenografts in nude mouse, accompanied by the reduction of PI3K, Akt, cyclin D1, CDK4, cycln E and significant increase of

  10. Association between cyclin D1 (CCND1) G870A polymorphism and gastric cancer risk: a meta-analysis

    PubMed Central

    Zhang, Yafei; Zeng, Xianling; Lu, Hongwei; Ji, Hong; Zhao, Enfa; Li, Yiming

    2016-01-01

    Published data on the association between cyclin D1 (CCND1) G870A polymorphism and gastric cancer (GC) risk are inconclusive. Thus, we conducted a meta-analysis to evaluate the relationship between CCND1 G870A polymorphism and GC risk. We searched PubMed, EMBASE, Web of science and the Cochrane Library up to June 12, 2015 for relevant studies. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to estimate the strength of associations. Nine studies published from 2003 to 2014, with a total of 1813 cases and 2173 controls, were included in this meta-analysis. The pooled results showed that there was no association between CCND1 G870A polymorphism and GC risk in any genetic model. The subgroup analysis stratified by ethnicity showed an increased breast cancer risk in Caucasian based on heterozygote comparison (GA vs. GG: OR=1.49, 95% CI=1.06-2.10, P=0.02). We found the same association in population based (PB) stratified analyses by Source of controls (AA vs. GG: OR=1.39, 95% CI=1.01-1.93, 0.05). When stratifying by the type, Sex and H. pylori infection in dominant model, Interestingly, we found the opposite result in Male (AA + GA vs. GG: OR=0.5, 95% CI=0.33-0.76, P=0.001), there were no association between CCND1 G870A polymorphism and GC risk in any other subgroup. This meta-analysis suggests that CCND1 G870A polymorphism is a risk factor for susceptibility to GC in Caucasians and in general populations. While, CCND1 G870A polymorphism plays a possible protective effect in GC in Male. Further large scale multicenter epidemiological studies are warranted to confirm this finding. PMID:27623072

  11. Multiparameter immunohistochemical analysis of the cell cycle proteins cyclin D1, Ki-67, p21WAF1, p27KIP1, and p53 in mantle cell lymphoma.

    PubMed

    Izban, K F; Alkan, S; Singleton, T P; Hsi, E D

    2000-10-01

    Mantle cell lymphoma (MCL) is characterized by overexpression of cyclin D1, a G1 cyclin that participates in the control of cell cycle progression at the G1 to S phase transition. In addition to cyclin D1, other cell cycle regulatory molecules may be involved in the proliferation and progression of MCL. Mutation of p53, deletion of p16(INK4a), and loss of p21(WAF1) expression have been reported in some cases of blastoid MCL. We sought to examine levels of expression of these proteins in typical and blastoid MCL and to determine whether differences were present between these subtypes of lymphomas. A retrospective series of typical and blastoid MCLs was evaluated for expression of the cell cycle-related proteins cyclin D1, p21(WAF1), p27(KIP1), Ki-67, and p53, as well as mitotic index. Paraffin-embedded archival tissues from 24 MCL specimens (17 typical, 7 blastoid) were immunostained with antibodies to p21(WAF1), p27(KIP1), p53, Ki-67, and cyclin D1. The percentage of positive cells for each specimen was estimated by counting 1500 cells under oil immersion microscopy. Levels of antigen expression were compared for the typical and blastoid MCLs. The mitotic index was estimated using twenty 100x oil immersion fields (OIFs) for each specimen. Cyclin D1 expression was seen in 22/24 specimens (92%). Blastoid MCLs were characterized by a significantly higher mean mitotic index (>20 mitoses/20 OIFs) and Ki-67 index (>45%) when compared with typical MCLs (P <.001 and P <.008, respectively; Fisher's exact test). High expression of p27(KIP1) (>25% staining) was seen more frequently in typical MCLs than in the blastoid variants (P =.03; Fisher's exact test). No significant differences were found between typical and blastoid MCLs for the expression of p21(WAF1) or p53. A significantly higher mitotic index and Ki-67 index were found in blastoid MCLs as compared with typical MCLs. Low p27(KIP1) expression was associated with the blastoid MCL variant. These findings confirm the

  12. Hog1 Targets Whi5 and Msa1 Transcription Factors To Downregulate Cyclin Expression upon Stress

    PubMed Central

    González-Novo, Alberto; Jiménez, Javier; Clotet, Josep; Nadal-Ribelles, Mariona; Cavero, Santiago

    2015-01-01

    Yeast cells have developed complex mechanisms to cope with extracellular insults. An increase in external osmolarity leads to activation of the stress-activated protein kinase Hog1, which is the main regulator of adaptive responses, such as gene expression and cell cycle progression, that are essential for cellular survival. Upon osmostress, the G1-to-S transition is regulated by Hog1 through stabilization of the cyclin-dependent kinase inhibitor Sic1 and the downregulation of G1 cyclin expression by an unclear mechanism. Here, we show that Hog1 interacts with and phosphorylates components of the core cell cycle transcriptional machinery such as Whi5 and the coregulator Msa1. Phosphorylation of these two transcriptional regulators by Hog1 is essential for inhibition of G1 cyclin expression, for control of cell morphogenesis, and for maximal cell survival upon stress. The control of both Whi5 and Msa1 by Hog1 also revealed the necessity for proper coordination of budding and DNA replication. Thus, Hog1 regulates G1 cyclin transcription upon osmostress to ensure coherent passage through Start. PMID:25733686

  13. Aberrant expression pattern and location of cullin 1 are associated with the development of papillary carcinoma in thyroid and cyclin D1 expression.

    PubMed

    Do, Sung-Im; Kim, Kyungeun; Lee, Hyunjoo; Kim, Hyun-Soo; Do, Tae Gu; Yun, Jisup; Kim, Dong-Hoon; Chae, Seoung Wan; Park, Yong Lai; Park, Chan Heun; Sohn, Jin Hee; Min, Kyueng-Whan; Pyo, Jung-Soo

    2014-09-01

    Cullin 1 (Cul1) is a rigid scaffold protein of a major class of E3 ubiquitin ligase, also known as the Skp1/cullin1/F-box (SCF) complex, which is involved in cell-cycle progression. The aberrant expression of Cul1 is involved in the dysfunction of SCF E3 ligase. Previous studies have revealed an association between increased Cul1 expression and tumor progression and poor outcome in several different tumors. We constructed a tissue microarray containing 103 papillary carcinoma tissues of the thyroid and 66 normal thyroid tissues. Cul1 expression and Cyclin D1 expression were evaluated by immunohistochemistry staining, and the relationship between their expression and clinicopathological parameters were analyzed. Cytoplasmic expression of Cul1 was correlated with tumor occurrence (p < 0.001), N stage (p = 0.027), and Cyclin D1 expression (p < 0.001). Cyclin D1 expression showed a correlation with tumor occurrence (p < 0.001) and T stage (p = 0.009). On the other hand, nuclear expression of Cul1 showed a negative correlation with tumor occurrence (p < 0.001) and Cyclin D1 expression (p < 0.001). Cytoplasmic Cul1 expression was associated with tumor development and higher nodal metastasis status, supporting the idea that the SCF complex is involved in cell-cycle regulation and promotes cell proliferation. Nuclear expression of Cul1 showed inverse relationship between tumor aggressiveness factors. Our data suggest that the expression site of Cul1 may affect the function of the SFC complex and play a role in tumor progression.

  14. Cigarette smoke extract alters the cell cycle via the phospholipid transfer protein/transforming growth factor-β1/CyclinD1/CDK4 pathway.

    PubMed

    Chai, Xue-Min; Li, You-Lun; Chen, Hong; Guo, Shu-Liang; Shui, Li-Li; Chen, Ya-Juan

    2016-09-05

    This study was aimed to investigate the effect of phospholipid transfer protein (PLTP) on cigarette smoke extract (CSE)-induced alteration of the cell cycle and the possible mechanism. Male Wistar rats and the rat alveolar epithelial cell line (RLE-6TN) were exposed to normal air or different concentrations of CSE. Then PLTP siRNA was transfected into cells and an inhibitor of transforming growth factor-β1 (TGF-β1) was administered prior to CSE exposure. Histological changes and cell cycle stage were recorded, as were the expression levels of PLTP, TGF-β1, CyclinD1 and CDK4. Resulting morphological changes included diffuse interstitial substance incrassation and elevated alveolar rupturing. Flow cytometry analysis revealed an increase in the number of cells in the G1 phase in a time- and dose-related manner. Both PLTP and TGF-β1 were up-regulated at protein and mRNA levels, whereas CyclinD1 and CDK4 expression was down-regulated after CSE exposure. Furthermore, PLTP siRNA significantly suppressed CSE-induced TGF-β1 expression, resulting in up-regulation of CyclinD1 and CDK4, but the TGF-β1 inhibitor was not able to abrogate CSE-induced PLTP over-expression. In conclusion, PLTP may operate upstream of the TGF-β1/CyclinD1/CDK4 pathway and may mediate the CSE-induced G1 arrest in RLE-6TN cells. Our work provides some new insight into the relation between PLTP and cell cycle progression.

  15. Gain of 11q/cyclin D1 overexpression is an essential early step in skin cancer development and causes abnormal tissue organization and differentiation.

    PubMed

    Burnworth, B; Popp, S; Stark, H-J; Steinkraus, V; Bröcker, E B; Hartschuh, W; Birek, C; Boukamp, P

    2006-07-27

    Non-melanoma skin cancers, in particular keratoacanthomas (KAs) and squamous cell carcinomas (SCCs), have become highly frequent tumor types especially in immune-suppressed transplant patients. Nevertheless, little is known about essential genetic changes. As a paradigm of 'early' changes, that is, changes still compatible with tumor regression, we studied KAs by comparative genomic hybridization and show that gain of chromosome 11q is not only one of the most frequent aberration (8/18), but in four tumors also the only aberration. Furthermore, 11q gain correlated with amplification of the cyclin D1 locus (10/14), as determined by fluorescence in situ hybridization, and overexpression of cyclin D1 protein (25/31), as detected by immunohistochemistry. For unraveling the functional consequence, we overexpressed cyclin D1 in HaCaT skin keratinocytes. These cells only gained little growth advantage in conventional and in organotypic co-cultures. However, although the control vector-transfected cells formed a well-stratified and orderly differentiated epidermis-like epithelium, they showed deregulation of tissue architecture with an altered localization of proliferation and impaired differentiation. The most severe phenotype was seen in a clone that additionally upregulated cdk4 and p21. These cells lacked terminal differentiation, exhibited a more autonomous growth in vitro and in vivo and even formed tumors in two injection sites with a growth pattern resembling that of human KAs. Thus, our results identify 11q13 gain/cyclin D1 overexpression as an important step in KA formation and point to a function that exceeds its known role in proliferation by disrupting tissue organization and thereby allowing abnormal growth.

  16. Alterations of cell cycle control proteins SHP‑1/2, p16, CDK4 and cyclin D1 in radioresistant nasopharyngeal carcinoma cells.

    PubMed

    Peng, Gang; Cao, Ru-Bo; Li, Yue-Hua; Zou, Zhen-Wei; Huang, Jing; Ding, Qian

    2014-10-01

    The primary treatment for nasopharyngeal carcinoma (NPC) is radiotherapy, with or without concurrent chemotherapy. However, resistance to radiotherapy is not uncommon. The aim of the present study was to establish a radioresistant NPC cell line to study the molecular mechanisms of radioresistance by measuring the expression of cell cycle control proteins src homology 2 domain-containing phosphatase (SHP)-1/2, p16, CDK4 and cyclin D1. Human nasopharyngeal carcinoma CNE‑2 cells were cultured, divided into two groups (CNE-2S1 and CNE-2S2) and irradiated with a dose of 6 Gy x5 or 2 Gy x15, respectively. The cells were subcultured between doses of irradiation. The surviving sublines (CNE-2S1 and CNE-2S2 clones) were then passaged for three months and their radiosensitivity was determined. The cell cycle distribution and protein expression of SHP-1/2, p16, CDK4 and cyclin D1 in parental and progenitor cell lines were measured. Small interfering (si)RNA-mediated knockdown of SHP-1 and SHP‑2 in the NPC cells was used to further examine their roles in radiosensitivity and cell cycle distribution. CNE-2S1, a radio‑resistant cell line, had a significantly higher percentage of cells in S phase and a lower percentage of cells in G1 phase, enhanced expression levels of SHP-1, CDK4 and cyclin D1, and reduced expression of p16, respectively, as compared with the parent cells. Stable suppression of SHP-1 mRNA in CNE‑2 cells resulted in increased radiosensitivity compared with the parental cells, a decrease in the number of cells in S phase and an increase in the expression of p16. The results suggested that the SHP‑1/p16/cyclin D1/CDK4 pathway may have a role in regulating radiosensitivity and cell cycle distribution in nasopharyngeal cells.

  17. Knocking-down of CREPT prohibits the progression of oral squamous cell carcinoma and suppresses cyclin D1 and c-Myc expression.

    PubMed

    Ma, Juntao; Ren, Yipeng; Zhang, Lei; Kong, Xiangpan; Wang, Tong; Shi, Yueyi; Bu, Rongfa

    2017-01-01

    As a regulator essential for many cell cycle-related proteins, the robust expression of Cell cycle-Related and Expression-elevated Protein in Tumor (CREPT) implicates a poor diagnosis of endoderm and mesoderm-derived tumors. Whether CREPT plays the same role in the tumorigenesis derived from ectodermal tissues remains elusive. To explore the role of CREPT in ectoderm-derived tumors, cells from 7oral squamous cell carcinoma (OSCC) lines and 84clinical OSCC samples were exploited in this study. Quantitative PCR, Western blot assay and immunohistochemistry were applied in the evaluation of CREPT, cyclin D1 and c-Myc expression. Knocking-down of CREPT was performed by lentivirus delivering specific shRNA of CREPT. The effects of CREPT on OSCC were examined by cell proliferation, colony formation, apoptosis, cell migration and xenograft implantation experiments. Compared with human normal oral keratinocytes, OSCC cell lines showed a significantly elevated expression of CREPT in both mRNA and protein levels. Consistently, samples from OSCC patients also exhibited a noticeably stronger CREPT expression than the noncancerous samples. In contrast, knocking down of CREPT in OSCC cell lines significantly reduced proliferation, colony formation and migration as well as the expression of cyclin D1 and c-Myc, but promoted apoptosis. Statistical analysis also suggested that CREPT expression was significantly correlated with the T and N classification of OSCC. Furthermore, CAL27 mouse xenograft model confirmed that down-regulation of CREPT prohibited cyclin D1 and c-Myc expression, through which decreased the in vivo tumor growth, but increased the survival ratio of hosts. In OSCC cell lines, up-regulated CREPT expression enhanced cell proliferation, migration and cell cycle as well as promoted cyclin D1 and c-Myc expression as it did in endoderm and mesoderm-origin tumors. Our study strongly suggests that CREPT could be used as a marker for the OSCC prognosis and might work as a

  18. Mig-6 is down-regulated in HCC and inhibits the proliferation of HCC cells via the P-ERK/Cyclin D1 pathway.

    PubMed

    Li, Zixuan; Qu, Lianyue; Luo, Wenting; Tian, Yulong; Zhai, Huan; Xu, Ke; Zhong, Hongshan

    2017-06-01

    The ablation of Mig-6 has been shown to induce tumor formation in various tissues. However, the relationships between Mig-6 expression, clinical pathological factors, and prognosis have not been clarified in hepatocellular carcinoma (HCC), and the mechanism by which Mig-6 regulates the proliferation of HCC cells has not been reported. In this study, we investigated the clinical significance of the loss of Mig-6 expression in HCC and the mechanism underlying the inhibition of cell proliferation by Mig-6. The down-regulation of Mig-6 correlated significantly with large tumors, a more advanced BCLC stage, and a more advanced TNM stage, and low Mig-6 expression predicted significantly reduced survival. Low Mig-6 expression and high Cyclin D1 expression were independent predictors for survival. The overexpression of Mig-6 led to significant G1 arrest and growth inhibition in HCC cells, possibly through the inhibition P-ERK and Cyclin D1. These results indicate that Mig-6 expression is low in HCC, which predicts a poor prognosis. Mig-6 may regulate cell proliferation and the cell cycle through the P-ERK/Cyclin D1 pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    SciTech Connect

    Zhang Dongyun; Li Jingxia; Gao Jimin; Huang Chuanshu

    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 cell 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.

  20. Mitochondrial reactive oxygen species perturb AKT/cyclin D1 cell cycle signaling via oxidative inactivation of PP2A in lowdose irradiated human fibroblasts.

    PubMed

    Shimura, Tsutomu; Sasatani, Megumi; Kamiya, Kenji; Kawai, Hidehiko; Inaba, Yohei; Kunugita, Naoki

    2016-01-19

    Here we investigated the cellular response of normal human fibroblasts to repeated exposure to low-dose radiation. In contrast to acute single radiation, low-dose fractionated radiation (FR) with 0.01 Gy/fraction or 0.05 Gy/fraction for 31 days increased in mitochondrial mass, decreased cellular levels of the antioxidant glutathione and caused persistent accumulation of mitochondrial reactive oxygen species (ROS). Excess ROS promoted oxidative inactivation of protein phosphatase PP2A which in turn led to disruption of normal negative feed-back control of AKT/cyclin D1 signaling in cells treated with long-term FR. The resulting abnormal nuclear accumulation of cyclin D1 causes growth retardation, cellular senescence and genome instability in low-dose irradiated cells. Thus, loss of redox control and subsequently elevated levels of ROS perturb signal transduction as a result of oxidative stress. Our study highlights a specific role of mitochondrial ROS in perturbation of AKT/cyclin D1 cell cycle signaling after low-dose long-term FR. The antioxidants N-acetyl-L-cysteine, TEMPO and mitochondrial-targeted antioxidant Mito-TEMPO provided protection against the harmful cell cycle perturbations induced by low-dose long-term FR.

  1. Alterations of pRb1-cyclin D1-cdk4/6-p16(INK4A) pathway in endometrial carcinogenesis.

    PubMed

    Semczuk, Andrzej; Jakowicki, Jerzy Andrzej

    2004-01-08

    The retinoblastoma protein pathway (pRb1-cyclin D1-cdk4/6-p16(INK4A)) participates in the regulation of the cellular processes at the transition of G1/S phases of the cell-cycle. Derailments of this pathway, caused either by lack of pRb1 or p16(INK4A) expression or overexpression of cyclin D1 and/or cdk4/6, are implicated in the deregulation of the cell-cycle machinery, resulting in uncontrolled cell proliferation, tumor heterogeneity, invasion and metastasis. Several studies conducted so far have assessed the deregulation of the pRb1-pathway components in various human tumors and cell-lines, provided these pathway alterations play an obligatory role in tumorigenesis. This review briefly summarizes the current information on the pRb1-cyclin D1-cdk4/6-p16(INK4A) alterations in sporadic uterine cancer, placing emphasis on the influence on the dualistic model of endometrial carcinogenesis.

  2. Involvement of the cAMP Response Element Binding Protein, CREB, and Cyclin D1 in LPA-Induced Proliferation of P19 Embryonic Carcinoma Cells

    PubMed Central

    Kim, Min-Jung; Sun, Yuanjie; Yang, Haijie; Kim, Nam-Ho; Jeon, Sung Ho; Huh, Sung-Oh

    2012-01-01

    Lysophosphatidic acid (LPA) is a lipid growth factor that induces proliferation of fibroblasts by activating the cAMP response element binding protein (CREB). Here, we further investigated whether LPA induces proliferation of P19 cells, a line of pluripotent embryonic carcinoma cells. 5′-Bromo-2-deoxyuridine incorporation and cell viability as-says showed that LPA stimulated proliferation of P19 cells. Immunoblot experiments with P19 cells revealed that the mitogen activated protein kinases, including p-ERK, p38, pAKT, glycogen synthase kinase 3β, and CREB were phosphorylated by treatment with 10 μM LPA. LPA-induced phosphorylation of CREB was efficiently blocked by U0126 and H89, inhibitors of the MAP kinases ERK1/2 and mitogen- and stress-activated protein kinase 1, respectively. Involvement of cyclin D1 in LPA-induced P19 cell proliferation was verified by immunoblot analysis in combination with pharmacological inhibitor treatment. Furthermore, LPA up-regulated CRE-harboring cyclin D1 promoter activity, suggesting that CREB and cyclin D1 play significant roles in LPA-induced proliferation of P19 embryonic carcinoma cells. PMID:22847216

  3. Association between cyclin D1 G870A polymorphism and hepatocellular carcinoma risk: a meta-analysis

    PubMed Central

    Luo, Tao; Chen, Jie; Liu, Jun-Jie; Li, Hang; You, Xue-Mei; Wang, Hong-Liang; Zhu, Shao-Liang; Li, Le-Qun

    2016-01-01

    Background Cyclin D1 (CCND1) G870A polymorphism may be associated with hepatocellular carcinoma (HCC) risk, but the results of previous studies were inconsistent. Available evidence was meta-analyzed to assess their potential association. Methods Databases PubMed, EMBASE, Cochrane Library, Web of Science, Chinese Biomedical Literature database, China National Knowledge Infrastructure, and Google Scholar were systematically searched. Meta-analyses were performed to investigate the association of G870A polymorphism with HCC risk by calculating odds ratios (ORs) and 95% confidence intervals (CIs) from the data of relevant case–control studies. Results Results of this meta-analysis of six case–control studies involving 1,030 cases and 1,683 controls indicate that G870A polymorphism was not associated with HCC risk in any of the five genetic models tested (recessive model: AA vs GG + AG: OR =1.38, 95% CI =0.95–2.00, P=0.09; dominant model: AG + AA vs GG: OR =1.38, 95% CI =0.87–2.20, P=0.17; homozygous model: AA vs GG: OR =1.60, 95% CI =0.87–2.94, P=0.13; heterozygous model: AG vs GG: OR =1.24, 95% CI =0.86–1.79, P=0.25; allelic model: A vs G: OR =1.30, 95% CI =0.95–1.80, P=0.10). Subgroup analyses according to ethnicity showing marginally significant association between this single nucleotide polymorphism and HCC risk indicate that G870A may be significantly associated with HCC risk in Caucasian populations (recessive model: AA vs GG + AG: OR =2.34, 95% CI =1.60–3.42, P<0.0001; dominant model: AG + AA vs GG: OR =2.44, 95% CI =1.19–4.97, P=0.01; homozygous model: AA vs GG: OR =3.42, 95% CI =1.80–6.50, P=0.0002; allelic model: A vs G: OR =2.06, 95% CI =1.31–3.24, P=0.002), but not in Asian populations. Conclusion Available evidence suggests that no significant association between G870A polymorphism and HCC risk was found in either total populations or Asian populations. However, significant association was found in Caucasian populations. These

  4. The different roles of cyclinD1-CDK4 in STP and mGluR-LTD during the postnatal development in mice hippocampus area CA1.

    PubMed

    Li, Chenchen; Li, Xinmei; Chen, Weiheng; Yu, Shanshan; Chen, Jutao; Wang, Huili; Ruan, Diyun

    2007-05-30

    Cell-cycle-related proteins, such as cyclins or cyclin-dependent kinases, may have functions beyond that of cell cycle regulation. The expression and translocation of cyclinD1-CDK4 in post-mitotic neurons indicate that they may have supplementary functions in differentiated neurons that might be associated with neuronal plasticity. In the present study, our findings showed that the expression of CDK4 was localized mostly in nuclei and cytoplasm of pyramidal cells of CA1 at postnatal day 10 (P10); whereas at P28 staining of CDK4 could be detected predominantly in the cytoplasm but not nuclei. Basal synaptic transmission was normal in the presence of CDK4 inhibitor. Short-term synaptic plasticity (STP) was impaired in CDK4 inhibitor pre-treated slices both from neonatal (P8-15) and adolescent (P21-35) animals; however there was no significant change in paired-pulse facilitation (PPF) in slices pre-incubated with the CDK4 inhibitor from adolescent animals. By the treatment of CDK4 inhibitor, the induction or the maintenance of Long-term potentiation (LTP) in response to a strong tetanus and NMDA receptor-dependent long-term depression (LTD) were normal in hippocampus. However, long-term depression (LTD) induced either by group I metabotropic glutamate receptors (mGluRs) agonist or by paired-pulse low-frequency stimulation (PP-LFS) was impaired in CDK4 inhibitor pretreated slices both from neonatal and adolescent animals. But the effects of the CDK4 inhibitor at slices from adolescent animals were not as robust as at slices from neonatal animals. Our results indicated that the activation of cyclinD1-CDK4 is required for short-term synaptic plasticity and mGluR-dependent LTD, and suggested that this cyclin-dependent kinase may have different roles during the postnatal development in mice hippocampus area CA1.

  5. Distinction between Asymptomatic Monoclonal B-cell Lymphocytosis with Cyclin D1 Overexpression and Mantle Cell Lymphoma: From Molecular Profiling to Flow Cytometry

    PubMed Central

    Espinet, Blanca; Ferrer, Ana; Bellosillo, Beatriz; Nonell, Lara; Salar, Antonio; Fernández-Rodríguez, Concepción; Puigdecanet, Eulàlia; Gimeno, Javier; Garcia-Garcia, Mar; Carmen Vela, Maria; Luño, Elisa; Collado, Rosa; Navarro, José Tomás; de la Banda, Esmeralda; Abrisqueta, Pau; Arenillas, Leonor; Serrano, Cristina; Lloreta, Josep; Miñana, Belén; Cerutti, Andrea; Florensa, Lourdes; Orfao, Alberto; Sanz, Ferran; Solé, Francesc; Dominguez-Sola, David; Serrano, Sergio

    2015-01-01

    Purpose According to current diagnostic criteria, mantle cell lymphoma (MCL) encompasses the usual, aggressive variants and rare, nonnodal cases with monoclonal asymptomatic lymphocytosis, cyclin D1–positive (MALD1). We aimed to understand the biology behind this clinical heterogeneity and to identify markers for adequate identification of MALD1 cases. Experimental Design We compared 17 typical MCL cases with a homogeneous group of 13 untreated MALD1 cases (median follow-up, 71 months). We conducted gene expression profiling with functional analysis in five MCL and five MALD1. Results were validated in 12 MCL and 8 MALD1 additional cases by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and in 24 MCL and 13 MALD1 cases by flow cytometry. Classification and regression trees strategy was used to generate an algorithm based on CD38 and CD200 expression by flow cytometry. Results We found 171 differentially expressed genes with enrichment of neoplastic behavior and cell proliferation signatures in MCL. Conversely, MALD1 was enriched in gene sets related to immune activation and inflammatory responses. CD38 and CD200 were differentially expressed between MCL and MALD1 and confirmed by flow cytometry (median CD38, 89% vs. 14%; median CD200, 0% vs. 24%, respectively). Assessment of both proteins allowed classifying 85% (11 of 13) of MALD1 cases whereas 15% remained unclassified. SOX11 expression by qRT-PCR was significantly different between MCL and MALD1 groups but did not improve the classification. Conclusion We show for the first time that MALD1, in contrast to MCL, is characterized by immune activation and driven by inflammatory cues. Assessment of CD38/CD200 by flow cytometry is useful to distinguish most cases of MALD1 from MCL in the clinical setting. MALD1 should be identified and segregated from the current MCL category to avoid overdiagnosis and unnecessary treatment. PMID:24352646

  6. Role of the mTORC1 complex in satellite cell activation by RNA-induced mitochondrial restoration: dual control of cyclin D1 through microRNAs.

    PubMed

    Jash, Sukanta; Dhar, Gunjan; Ghosh, Utpalendu; Adhya, Samit

    2014-10-01

    During myogenesis, satellite stem cells (SCs) are induced to proliferate and differentiate to myogenic precursors. The role of energy sensors such as the AMP-activated protein kinase (AMPK) and the mammalian Target of Rapamycin (mTOR) in SC activation is unclear. We previously observed that upregulation of ATP through RNA-mediated mitochondrial restoration (MR) accelerates SC activation following skeletal muscle injury. We show here that during regeneration, the AMPK-CRTC2-CREB and Raptor-mTORC-4EBP1 pathways were rapidly activated. The phosho-CRTC2-CREB complex was essential for myogenesis and activated transcription of the critical cell cycle regulator cyclin D1 (Ccnd1). Knockdown (KD) of either mTORC or its subunit Raptor delayed SC activation without influencing the differentiation program. KD of 4EBP1 had no effect on SC activation but enhanced myofiber size. mTORC1 positively regulated Ccnd1 translation but destabilized Ccnd1 mRNA. These antithetical effects of mTORC1 were mediated by two microRNAs (miRs) targeted to the 3' untranslated region (UTR) of Ccnd1 mRNA: miR-1 was downregulated in mTORC-KD muscle, and depletion of miR-1 resulted in increased levels of mRNA without any effect on Ccnd1 protein. In contrast, miR-26a was upregulated upon mTORC depletion, while anti-miR-26a oligonucleotide specifically stimulated Ccnd1 protein expression. Thus, mTORC may act as a timer of satellite cell proliferation during myogenesis.

  7. Nuclear PRMT5, cyclin D1 and IL-6 are associated with poor outcome in oropharyngeal squamous cell carcinoma patients and is inversely associated with p16-status

    PubMed Central

    Kumar, Bhavna; Yadav, Arti; Brown, Nicole V.; Zhao, Songzhu; Cipolla, Michael J.; Wakely, Paul E.; Schmitt, Alessandra C.; Baiocchi, Robert A.; Teknos, Theodoros N.

    2017-01-01

    Protein arginine methyltransferase-5 (PRMT5) plays an important role in cancer progression by repressing the expression of key tumor suppressor genes via the methylation of transcriptional factors and chromatin-associated proteins. However, very little is known about the expression and biological role of PRMT5 in head and neck cancer. In this study, we examined expression profile of PRMT5 at subcellular levels in oropharyngeal squamous cell carcinoma (OPSCC) and assessed its correlation with disease progression and patient outcome. Our results show that nuclear PRMT5 was associated with poor overall survival (p < 0.012) and these patients had 1.732 times higher hazard of death (95% CI: 1.127–2.661) as compared to patients in whom PRMT5 was not present in the nucleus of the tumors. Nuclear PRMT5 expression was inversely correlated with p16-status (p < 0.001) and was significantly higher in tumor samples from patients who smoked > 10 pack-years (p = 0.013). In addition, nuclear PRMT5 was directly correlated with cyclin D1 (p = 0.0101) and IL-6 expression (p < 0.001). In a subgroup survival analysis, nuclear PRMT5-positive/IL-6-positive group had worst survival, whereas nuclear PRMT5-negative/IL-6-negative group had the best survival. Similarly, patients with p16-negative/nuclear PRMT5-positive tumors had worse survival compared to patients with p16-positive/nuclear PRMT5-negative tumors. Our mechanistic results suggest that IL-6 promotes nuclear translocation of PRMT5. Taken together, our results demonstrate for the first time that nuclear PRMT5 expression is associated with poor clinical outcome in OPSCC patients and IL-6 plays a role in the nuclear translocation of PRMT5. PMID:28107179

  8. Nuclear PRMT5, cyclin D1 and IL-6 are associated with poor outcome in oropharyngeal squamous cell carcinoma patients and is inversely associated with p16-status.

    PubMed

    Kumar, Bhavna; Yadav, Arti; Brown, Nicole V; Zhao, Songzhu; Cipolla, Michael J; Wakely, Paul E; Schmitt, Alessandra C; Baiocchi, Robert A; Teknos, Theodoros N; Old, Matthew; Kumar, Pawan

    2017-01-17

    Protein arginine methyltransferase-5 (PRMT5) plays an important role in cancer progression by repressing the expression of key tumor suppressor genes via the methylation of transcriptional factors and chromatin-associated proteins. However, very little is known about the expression and biological role of PRMT5 in head and neck cancer. In this study, we examined expression profile of PRMT5 at subcellular levels in oropharyngeal squamous cell carcinoma (OPSCC) and assessed its correlation with disease progression and patient outcome. Our results show that nuclear PRMT5 was associated with poor overall survival (p < 0.012) and these patients had 1.732 times higher hazard of death (95% CI: 1.127-2.661) as compared to patients in whom PRMT5 was not present in the nucleus of the tumors. Nuclear PRMT5 expression was inversely correlated with p16-status (p < 0.001) and was significantly higher in tumor samples from patients who smoked > 10 pack-years (p = 0.013). In addition, nuclear PRMT5 was directly correlated with cyclin D1 (p = 0.0101) and IL-6 expression (p < 0.001). In a subgroup survival analysis, nuclear PRMT5-positive/IL-6-positive group had worst survival, whereas nuclear PRMT5-negative/IL-6-negative group had the best survival. Similarly, patients with p16-negative/nuclear PRMT5-positive tumors had worse survival compared to patients with p16-positive/nuclear PRMT5-negative tumors. Our mechanistic results suggest that IL-6 promotes nuclear translocation of PRMT5. Taken together, our results demonstrate for the first time that nuclear PRMT5 expression is associated with poor clinical outcome in OPSCC patients and IL-6 plays a role in the nuclear translocation of PRMT5.

  9. Cyclin A expression is under negative transcriptional control during the cell cycle.

    PubMed Central

    Huet, X; Rech, J; Plet, A; Vié, A; Blanchard, J M

    1996-01-01

    Transcription of the gene coding for cyclin A, a protein required for S-phase transit, is cell cycle regulated and is restricted to proliferating cells. To further explore transcriptional regulation linked to cell division cycle control, a genomic clone containing 5' flanking sequences of the murine cyclin A gene was isolated. When it was fused to a luciferase reporter gene, it was shown to function as a proliferation-regulated promoter in NIH 3T3 cells. Transcription of the mouse cyclin A gene is negatively regulated by arrest of cell proliferation. A mutation of a GC-rich sequence conserved between mice and humans is sufficient to relieve transcriptional repression, resulting in a promoter with constitutively high activity. In agreement with this result, in vivo footprinting reveals a protection of the cell cycle-responsive element in G0/early G1 cells which is not observed at later stages of the cell cycle. Moreover, the footprint is present in dimethyl sulfoxide-induced differentiating and not in proliferating Friend erythroleukemia cells. Conversely, two other sites, which in vitro bind ATF-1 and NF-Y, respectively, are constitutively occupied throughout cell cycle progression. PMID:8668196

  10. 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.

  11. 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 Central

    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. PMID:28401064

  12. The transcription factor, the Cdk, its cyclin and their regulator: directing the transcriptional response to a nutritional signal.

    PubMed Central

    Hirst, K; Fisher, F; McAndrew, P C; Goding, C R

    1994-01-01

    The Pho80-Pho85 cyclin-cdk complex prevents transcription of PHO5 by inhibiting the ability of the basic-helix-loop-helix transcription factor Pho4 to activate transcription in response to high phosphate conditions. In low phosphate the Pho80-Pho85 complex is inactivated and Pho4 is then able to activate the acid phosphatase gene PHO5. We show here that Pho4 and the homeobox protein Pho2 interact in vivo and act cooperatively to activate the PHO5 UAS, with interaction being regulated by the phosphate switch. In addition, we also demonstrate that an additional factor, Pho81, interacts in high phosphate with both the Pho80 cyclin and with Pho4. In low phosphate, Pho80 and Pho81 dissociate from Pho4, but retain the ability to interact with each other. The evidence presented here supports the idea that Pho81 acts as a phosphate-sensitive trigger that regulates the ability of the Pho80-Pho85 cyclin-cdk complex to bind Pho4, while DNA binding by Pho4 is dependent on the phosphate-sensitive interaction with Pho2. Images PMID:7957107

  13. Downregulation of miR-34a contributes to the proliferation and migration of laryngeal carcinoma cells by targeting cyclin D1.

    PubMed

    Ye, Jin; Li, Laisheng; Feng, Pinning; Wan, Jianxin; Li, Jingjia

    2016-07-01

    Laryngeal carcinoma is one of the most common head and neck cancers. MicroRNAs are a class of small non-coding RNAs 18-25 nucleotides in length that post-transcriptionally regulate gene expression and have a pivotal role in many biological processes including cancer development. In this study, we investigated the role of miR-34a in laryngeal carcinoma and confirmed the regulation of cyclin D1 (CCND1) by miR-34a. We examined miR-34a expression levels in 71 laryngeal carcinoma patient specimens by quantitative reverse transcription-PCR, and analyzed the clinicopathological significance of the obtained data. Then, functional assays were performed to investigate the potential effects of miR-34a on cancer cell proliferation and migration. In addition, western blotting, luciferase reporter assay and several algorithms were conducted to confirm that CCND1 is directly regulated by miR-34a. We demonstrated that the miR-34a expression level was significantly downregulated in laryngeal carcinoma clinical specimens compared with that observed in their paired adjacent normal tissues. Additionally, miR-34a expression was also inversely correlated with lymph node metastasis and clinical stage. Functional assays showed that ectopic expression of miR-34a inhibited cell proliferation and migration in laryngeal carcinoma cells. Bioinformatic analysis identified CCND1 as a potential target of miR-34a. Moreover, we confirmed that miR-34a inhibited the expression of CCND1 by directly binding to its 3'-untranslated region. Silencing of CCND1 induced effects similar to those of miR-34a ectopic expression, and in laryngeal carcinoma tissues, miR-34a and CCND1 were inversely correlated. Our data suggest that tumor suppressor miR-34a could serve as a new potential diagnostic marker and that ectopic expression of miR-34a may be used as a therapeutic target for laryngeal carcinoma.

  14. NeuroD1 reprograms chromatin and transcription factor landscapes to induce the neuronal program.

    PubMed

    Pataskar, Abhijeet; Jung, Johannes; Smialowski, Pawel; Noack, Florian; Calegari, Federico; Straub, Tobias; Tiwari, Vijay K

    2016-01-04

    Cell fate specification relies on the action of critical transcription factors that become available at distinct stages of embryonic development. One such factor is NeuroD1, which is essential for eliciting the neuronal development program and possesses the ability to reprogram other cell types into neurons. Given this capacity, it is important to understand its targets and the mechanism underlying neuronal specification. Here, we show that NeuroD1 directly binds regulatory elements of neuronal genes that are developmentally silenced by epigenetic mechanisms. This targeting is sufficient to initiate events that confer transcriptional competence, including reprogramming of transcription factor landscape, conversion of heterochromatin to euchromatin, and increased chromatin accessibility, indicating potential pioneer factor ability of NeuroD1. The transcriptional induction of neuronal fate genes is maintained via epigenetic memory despite a transient NeuroD1 induction during neurogenesis. NeuroD1 also induces genes involved in the epithelial-to-mesenchymal transition, thereby promoting neuronal migration. Our study not only reveals the NeuroD1-dependent gene regulatory program driving neurogenesis but also increases our understanding of how cell fate specification during development involves a concerted action of transcription factors and epigenetic mechanisms.

  15. 4-Nerolidylcatechol: apoptosis by mitochondrial mechanisms with reduction in cyclin D1 at G0/G1 stage of the chronic myelogenous K562 cell line.

    PubMed

    Benfica, Polyana Lopes; Ávila, Renato Ivan de; Rodrigues, Bruna Dos Santos; Cortez, Alane Pereira; Batista, Aline Carvalho; Gaeti, Marilisa Pedroso Nogueira; Lima, Eliana Martins; Rezende, Kênnia Rocha; Valadares, Marize Campos

    2017-12-01

    4-Nerolidylcatechol (4-NRC) has showed antitumor potential through apoptosis. However, its apoptotic mechanisms are still unclear, especially in leukemic cells. To evaluate the cytotoxic potential of 4-NRC and its cell death pathways in p53-null K562 leukemic cells. Cytotoxicity of 4-NRC (4.17-534.5 μM) over 24 h of exposure was evaluated by MTT assay. 4-NRC-induced apoptosis in K562 cells was investigated by phosphatidylserine (PS) externalization, cell cycle, sub-G1, mitochondrial evaluation, cytochrome c, cyclin D1 and intracellular reactive oxygen species (ROS) levels, and caspase activity analysis. IC50 values obtained were 11.40, 27.31, 15.93 and 15.70 μM for lymphocytes, K562, HL-60 and Jurkat cells, respectively. In K562 cells, 4-NRC (27 μM) promoted apoptosis as verified by cellular morphological changes, a significant increase in PS externalization and sub-G1 cells. Moreover, it significantly arrested the cells at the G0/G1 phase due to a reduction in cyclin D1 expression. These effects of 4-NRC also significantly promoted a reduction in mitochondrial activity and membrane depolarization, accumulation of cytosolic cytochrome c and ROS overproduction. Additionally, it triggered an increase in caspases -3/7, -8 and -9 activities. When the cells were pretreated with N-acetyl-l-cysteine ROS scavenger, 4-NRC-induced apoptosis was partially blocked, which suggests that it exerts cytotoxicity though not exclusively through ROS-mediated mechanisms. 4-NRC has antileukemic properties, inducing apoptosis mediated by mitochondrial-dependent mechanisms with cyclin D1 inhibition. Given that emerging treatment concepts include novel combinations of well-known agents, 4-NRC could offer a promising alternative for chemotherapeutic combinations to maximize tumour suppression.

  16. BCL-1 (PRAD-1/cyclin D-1) overexpression distinguishes the blastoid variant of mantle cell lymphoma from B-lineage lymphoblastic lymphoma.

    PubMed

    Soslow, R A; Zukerberg, L R; Harris, N L; Warnke, R A

    1997-08-01

    The blastoid variant of mantle cell lymphoma (MCL-BV) can occur de novo or can represent a morphologic transformation of MCL associated with aggressive clinical disease. Its cytologic appearance is very similar to that of lymphoblastic lymphoma (LBL) because of its characteristic nuclear features and high proliferative rate. To assess the usefulness of antibodies to cyclin D-1 (BCL-1/ PRAD-1), CD99 (12E7), CD34, and TdT in distinguishing between MCL-BV and LBL in formalin-fixed, paraffin-embedded tissue, we studied from the Stanford data base 10 cases originally diagnosed as B-lineage LBL, 5 MCL-BVs, 2 cases thought likely to represent MCL-BV, and 2 blastic lymphomas whose morphology and immunophenotype were indeterminate. Six (60%) of 10 LBLs stained with CD99, as opposed to none of 7 MCL-BVs. Four (40%) of 10 LBLs reacted with CD34, as compared with none of 7 MCL-BVs. Eight (89%) of nine LBLs were positive for TdT, but all of the four MCL-BVs tested were negative. In contrast, the anti-cyclin D-1 antibody stained the nuclei of all of the MCL-BVs and none of the LBLs tested. On the basis of our evaluation, the probable MCL-BV cases were considered to be definite MCL-BV. Of the indeterminate cases, one was considered to be LBL, whereas we felt that the other represented MCL-BV. We conclude that staining formalin-fixed, paraffin-embedded, high-grade lymphomas with anti-cyclin D-1 antibody is useful in confirming the diagnosis of MCL-BV, whereas positive reactions with CD99, CD34, and particularly TdT are more characteristic of LBL.

  17. Rsf-1 is overexpressed in non-small cell lung cancers and regulates cyclinD1 expression and ERK activity

    SciTech Connect

    Li, Qingchang; Dong, Qianze; Wang, Enhua

    2012-03-30

    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-1 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.

  18. Knocking-down of CREPT prohibits the progression of oral squamous cell carcinoma and suppresses cyclin D1 and c-Myc expression

    PubMed Central

    Ma, Juntao; Ren, Yipeng; Zhang, Lei; Kong, Xiangpan; Wang, Tong; Shi, Yueyi; Bu, Rongfa

    2017-01-01

    Background As a regulator essential for many cell cycle-related proteins, the robust expression of Cell cycle-Related and Expression-elevated Protein in Tumor (CREPT) implicates a poor diagnosis of endoderm and mesoderm-derived tumors. Whether CREPT plays the same role in the tumorigenesis derived from ectodermal tissues remains elusive. Methods To explore the role of CREPT in ectoderm-derived tumors, cells from 7oral squamous cell carcinoma (OSCC) lines and 84clinical OSCC samples were exploited in this study. Quantitative PCR, Western blot assay and immunohistochemistry were applied in the evaluation of CREPT, cyclin D1 and c-Myc expression. Knocking-down of CREPT was performed by lentivirus delivering specific shRNA of CREPT. The effects of CREPT on OSCC were examined by cell proliferation, colony formation, apoptosis, cell migration and xenograft implantation experiments. Results Compared with human normal oral keratinocytes, OSCC cell lines showed a significantly elevated expression of CREPT in both mRNA and protein levels. Consistently, samples from OSCC patients also exhibited a noticeably stronger CREPT expression than the noncancerous samples. In contrast, knocking down of CREPT in OSCC cell lines significantly reduced proliferation, colony formation and migration as well as the expression of cyclin D1 and c-Myc, but promoted apoptosis. Statistical analysis also suggested that CREPT expression was significantly correlated with the T and N classification of OSCC. Furthermore, CAL27 mouse xenograft model confirmed that down-regulation of CREPT prohibited cyclin D1 and c-Myc expression, through which decreased the in vivo tumor growth, but increased the survival ratio of hosts. Conclusion In OSCC cell lines, up-regulated CREPT expression enhanced cell proliferation, migration and cell cycle as well as promoted cyclin D1 and c-Myc expression as it did in endoderm and mesoderm-origin tumors. Our study strongly suggests that CREPT could be used as a marker for

  19. Transcription factors of M-phase cyclin CLB2 in the yeast cell wall integrity checkpoint.

    PubMed

    Sekiya, Mizuho; Nogami, Satoru; Ohya, Yoshikazu

    2009-08-01

    The cell wall integrity checkpoint coordinates cell wall synthesis and mitosis in the budding yeast, Saccharomyces cerevisiae. It has been reported that this checkpoint arrests the cell cycle at G2/M phase with repression of the M phase cyclin Clb2p at the transcriptional level, under perturbation of cell wall synthesis. We demonstrate that an override of this checkpoint with accumulation of CLB2 mRNA is induced when negative CLB2 transcription factors are deleted or when positive CLB2 transcription factors are overproduced in cell wall-defective cells. Our data imply that transcription factors for CLB2 are involved in the cell wall integrity checkpoint system and suggest that there are multiple regulation pathways of the checkpoint.

  20. 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

  1. Modulations of benzo[a]pyrene-induced DNA adduct, cyclin D1 and PCNA in oral tissue by 1,4-phenylenebis(methylene)selenocyanate

    SciTech Connect

    Chen, Kun-Ming; Sacks, Peter G.; Spratt, Thomas E.; Lin, Jyh-Ming; Boyiri, Telih; Schwartz, Joel; Richie, John P.; Calcagnotto, Ana; Das, Arunangshu; Bortner, James; Zhao, Zonglin; Amin, Shantu; Guttenplan, Joseph; El-Bayoumy, Karam

    2009-05-22

    Tobacco smoking is an important cause of human oral squamous cell carcinoma (SCC). Tobacco smoke contains multiple carcinogens include polycyclic aromatic hydrocarbons typified by benzo[a]pyrene (B[a]P). Surgery is the conventional treatment approach for SCC, but it remains imperfect. However, chemoprevention is a plausible strategy and we had previously demonstrated that 1,4-phenylenebis(methylene)selenocyanate (p-XSC) significantly inhibited tongue tumors-induced by the synthetic 4-nitroquinoline-N-oxide (not present in tobacco smoke). In this study, we demonstrated that p-XSC is capable of inhibiting B[a]P-DNA adduct formation, cell proliferation, cyclin D1 expression in human oral cells in vitro. In addition, we showed that dietary p-XSC inhibits B[a]P-DNA adduct formation, cell proliferation and cyclin D1 protein expression in the mouse tongue in vivo. The results of this study are encouraging to further evaluate the chemopreventive efficacy of p-XSC initially against B[a]P-induced tongue tumors in mice and ultimately in the clinic.

  2. Same difference: A pilot study of cyclin D1, bcl-2, AMACR, and ALDH-1 identifies significant differences in expression between primary colon adenocarcinoma and its metastases.

    PubMed

    Oakley, Gerard J; Denning, Krista L; Graffeo, Vincent; Griswold, Doreen C; Davis, Adam R; Brown, Linda G

    2016-11-01

    Tumor heterogeneity implies the possibility of significantly different expression of key pathways between primary and metastatic clones. Colon adenocarcinoma is one of the few tumors where current practice includes resection of primary and isolated organ metastases simultaneously without neoadjuvant therapy. We performed a pilot study on 28 cases of colon adenocarcinoma resected simultaneously with metastases in patients with no history of neoadjuvant therapy. We assayed matched primary and metastatic tumors from each patient with common diagnostic antibodies to Bcl-2, Cyclin D1, AMACR, and ALDH-1 by immunohistochemistry with semi-quantitative interpretation on archived formalin fixed, paraffin embedded samples. We were powered for large, consistent differences between primary and metastatic expression, and found 21 of 28 had a significant difference in expression of at least one of the four proteins, accounting for multiplicity of testing. Cyclin D1 had significantly more cases with differential metastatic:primary expression than would be expected by chance alone (p-value 0.0043), favoring higher expression in the metastatic sample. Bcl-2 and ALDH-1 had trends in this direction (p-value 0.078 each). Proportionately more cases with significant differences were identified when a liver metastasis was tested. We conclude differences in expression between metastatic and primary colon adenocarcinoma within the same patient exist, and may have therapeutic and biomarker testing consequences.

  3. A proteomic study on cell cycle progression of endothelium exposed to tumor conditioned medium and the possible role of cyclin D1/E.

    PubMed

    Li, Ailing; Li, Hongwei; Jin, Gang; Xiu, Ruijuan

    2003-01-01

    This study was designed to comprehensively analyze the differential expression of proteins from human umbilical vein endothelial cells (HUVECs) exposed to tumor conditioned medium (TCM) and to identify the key regulator in the cell cycle progression. The HUVECs were exposed to TCM from breast carcinoma cell line MDA-MB-231, then their cell cycle distribution was measured by flow cytometer (FCM). The role of protein in cell cycle progression was detected via two-dimensional polyacrylamide gel electrophoresis (2-DE) and western blotting. Following the stimulation of TCM, HUVECs showed a more cells in the S phase than did the negative control group (ECGF-free medium with 20% FBS), but the HUVECs' level was similar to the positive control group (medium with 25 micrograms/ml ECGF and 20% FBS). Increased expression of cyclin D1/E and some changes in other related proteins occurred after incubation with TCM. From our results, we can conclude that breast carcinoma cell line MDA-MB-231 may secrete soluble pro-angiogenic factors that induce the HUVEC angiogenic switch, during which the expression of cell cycle regulator cyclin D1/E increases and related proteins play an important role in this process.

  4. The prognostic significance of β-catenin, cyclin D1 and PIN1 in minor salivary gland carcinoma: β-catenin predicts overall survival.

    PubMed

    Schneider, Sven; Thurnher, Dietmar; Seemann, Rudolf; Brunner, Markus; Kadletz, Lorenz; Ghanim, Bahil; Aumayr, Klaus; Heiduschka, Gregor; Lill, Claudia

    2016-05-01

    Minor salivary gland carcinoma is a rare and heterogeneous type of cancer. Molecular prognostic and predictive markers are sparse. The aim of this study was to identify new prognostic and predictive markers in minor salivary gland carcinoma. 50 tissue samples of carcinomas of the minor salivary glands (adenoid cystic carcinoma n = 23, mucoepidermoid carcinoma n = 12, adenocarcinoma n = 10, carcinoma ex pleomorphic adenoma n = 2, salivary duct carcinoma n = 1, clear cell carcinoma n = 1, basal cell carcinoma n = 1) were immunohistochemically stained for β-catenin, cyclin D1 and PIN1. Expression patterns were analyzed and correlated to clinical outcome of 37 patients with complete clinical data. High expression of membranous β-catenin was linked to significantly better overall survival in patients with adenoid cystic carcinoma (log rank test, χ (2) = 13.3, p = .00397, Bonferroni corrected p = .024). PIN1 and cyclin D1 did not show any significant correlation to patients' clinical outcome. Expression of β-catenin in adenoid cystic carcinoma of the minor salivary glands significantly correlates with better overall survival. Hence, evaluation of β-catenin might serve as a clinical prognostic marker.

  5. BMP6 Regulates Proliferation and Apoptosis of Human Sertoli Cells Via Smad2/3 and Cyclin D1 Pathway and DACH1 and TFAP2A Activation

    PubMed Central

    Wang, Hong; Yuan, Qingqing; Sun, Min; Niu, Minghui; Wen, Liping; Fu, Hongyong; Zhou, Fan; Chen, Zheng; Yao, Chencheng; Hou, Jingmei; Shen, Ruinan; Lin, Qisheng; Liu, Wenjie; Jia, Ruobing; Li, Zheng; He, Zuping

    2017-01-01

    Sertoli cells are essential for regulating normal spermatogenesis. However, the mechanisms underlying human Sertoli cell development remain largely elusive. Here we examined the function and signaling pathways of BMP6 in regulating human Sertoli cells. RT-PCR, immunocytochemistry and Western blots revealed that BMP6 and its multiple receptors were expressed in human Sertoli cells. CCK-8 and EDU assays showed that BMP6 promoted the proliferation of Sertoli cells. Conversely, BMP6 siRNAs inhibited the division of these cells. Annexin V/PI assay indicated that BMP6 reduced the apoptosis in human Sertoli cells, whereas BMP6 knockdown assumed reverse effects. BMP6 enhanced the expression levels of ZO1, SCF, GDNF and AR in human Sertoli cells, and ELISA assay showed an increase of SCF by BMP6 and a reduction by BMP6 siRNAs. Notably, Smad2/3 phosphorylation and cyclin D1 were enhanced by BMP6 and decreased by BMP6 siRNAs in human Sertoli cells. The levels of DACH1 and TFAP2A were increased by BMP6 and reduced by BMP6 siRNAs, and the growth of human Sertoli cells was inhibited by these siRNAs. Collectively, these results suggest that BMP6 regulates the proliferation and apoptosis of human Sertoli cells via activating the Smad2/3/cyclin D1 and DACH1 and TFAP2A pathway. PMID:28387750

  6. Marine steroids as potential anticancer drug candidates: In silico investigation in search of inhibitors of Bcl-2 and CDK-4/Cyclin D1.

    PubMed

    Saikia, Surovi; Kolita, Bhaskor; Dutta, Partha P; Dutta, Deep J; Neipihoi; Nath, Shyamalendu; Bordoloi, Manobjyoti; Quan, Pham Minh; Thuy, Tran Thu; Phuong, Doan Lan; Long, Pham Quoc

    2015-10-01

    Star fishes (Asteroidea) are rich in polar steroids with diverse structural characteristics. The structural modifications of star fish steroids occur at 3β, 4β, 5α, 6α (or β), 7α (or β), 8, 15α (or β) and 16β positions of the steroidal nucleus and in the side chain. Widely found polar steroids in starfishes include polyhydroxysteroids, steroidal sulfates, glycosides, steroid oligoglycosides etc. Bioactivity of these steroids is less studied; only a few reports like antibacterial, cytotoxic activity etc. are available. In continuation of our search for bioactive molecules from natural sources, we undertook in silico screening of steroids from star fishes against Bcl-2 and CDK-4/Cyclin D1 - two important targets of progression and proliferation of cancer cells. We have screened 182 natural steroids from star fishes occurring in different parts of the world and their 282 soft-derivatives by in silico methods. Their physico-chemical properties, drug-likeliness, binding potential with the selected targets, ADMET (absorption, distribution, metabolism, toxicity) were predicted. Further, the results were compared with those of existing steroidal and non steroidal drugs and inhibitors of Bcl-2 and CDK-4/Cyclin D1. The results are promising and unveil that some of these steroids can be potent leads for cancer treatments.

  7. Distinctive patterns of Her-2/neu, c-myc, and cyclin D1 gene amplification by fluorescence in situ hybridization in primary human breast cancers.

    PubMed

    Janocko, L E; Brown, K A; Smith, C A; Gu, L P; Pollice, A A; Singh, S G; Julian, T; Wolmark, N; Sweeney, L; Silverman, J F; Shackney, S E

    2001-06-15

    Human solid tumors undergo clonal evolution as they progress, but evidence for specific sequences of genetic changes that occur in individual tumors and are recapitulated in other tumors is difficult to obtain. Patterns of amplification of Her-2/neu, c-myc, and cyclin D1 were determined by fluorescence in situ hybridization (FISH) in relation to the presence of p53 dysfunction and ploidy in 60 primary human breast cancers. We show that there are clusters of genophenotypic abnormalities that distinguish lobular breast cancers from nonlobular tumors; that cyclin D1 amplification occurs prior to the divergence of lobular breast cancers from nonlobular cancers; that p53 dysfunction, Her-2/neu amplification, and c-myc amplification are characteristic features of nonlobular breast cancers, but not of lobular breast cancers; and that the frequencies of amplification of all three oncogenes examined increase progressively with increasing aneuploidy, but that each gene exhibits a different profile of increasing amplification in relation to tumor progression. Early amplification of c-myc appears to be an especially prominent feature of hypertetraploid/hypertetrasomic tumors. The data suggest that in tumors containing multiple abnormalities, these abnormalities often accumulate in the same cells within each tumor. Furthermore, the same patterns of accumulation of multiple genophenotypic abnormalities are recapitulated in different tumors.

  8. Mechanistic Target of Rapamycin (mTOR) Inhibition Synergizes with Reduced Internal Ribosome Entry Site (IRES)-mediated Translation of Cyclin D1 and c-MYC mRNAs to Treat Glioblastoma*

    PubMed Central

    Holmes, Brent; Lee, Jihye; Landon, Kenna A.; Benavides-Serrato, Angelica; Bashir, Tariq; Jung, Michael E.; Lichtenstein, Alan; Gera, Joseph

    2016-01-01

    Our previous work has demonstrated an intrinsic mRNA-specific protein synthesis salvage pathway operative in glioblastoma (GBM) tumor cells that is resistant to mechanistic target of rapamycin (mTOR) inhibitors. The activation of this internal ribosome entry site (IRES)-dependent mRNA translation initiation pathway results in continued translation of critical transcripts involved in cell cycle progression in the face of global eIF-4E-mediated translation inhibition. Recently we identified compound 11 (C11), a small molecule capable of inhibiting c-MYC IRES translation as a consequence of blocking the interaction of a requisite c-MYC IRES trans-acting factor, heterogeneous nuclear ribonucleoprotein A1, with its IRES. Here we demonstrate that C11 also blocks cyclin D1 IRES-dependent initiation and demonstrates synergistic anti-GBM properties when combined with the mechanistic target of rapamycin kinase inhibitor PP242. The structure-activity relationship of C11 was investigated and resulted in the identification of IRES-J007, which displayed improved IRES-dependent initiation blockade and synergistic anti-GBM effects with PP242. Mechanistic studies with C11 and IRES-J007 revealed binding of the inhibitors within the UP1 fragment of heterogeneous nuclear ribonucleoprotein A1, and docking analysis suggested a small pocket within close proximity to RRM2 as the potential binding site. We further demonstrate that co-therapy with IRES-J007 and PP242 significantly reduces tumor growth of GBM xenografts in mice and that combined inhibitor treatments markedly reduce the mRNA translational state of cyclin D1 and c-MYC transcripts in these tumors. These data support the combined use of IRES-J007 and PP242 to achieve synergistic antitumor responses in GBM. PMID:27226604

  9. Mechanistic Target of Rapamycin (mTOR) Inhibition Synergizes with Reduced Internal Ribosome Entry Site (IRES)-mediated Translation of Cyclin D1 and c-MYC mRNAs to Treat Glioblastoma.

    PubMed

    Holmes, Brent; Lee, Jihye; Landon, Kenna A; Benavides-Serrato, Angelica; Bashir, Tariq; Jung, Michael E; Lichtenstein, Alan; Gera, Joseph

    2016-07-01

    Our previous work has demonstrated an intrinsic mRNA-specific protein synthesis salvage pathway operative in glioblastoma (GBM) tumor cells that is resistant to mechanistic target of rapamycin (mTOR) inhibitors. The activation of this internal ribosome entry site (IRES)-dependent mRNA translation initiation pathway results in continued translation of critical transcripts involved in cell cycle progression in the face of global eIF-4E-mediated translation inhibition. Recently we identified compound 11 (C11), a small molecule capable of inhibiting c-MYC IRES translation as a consequence of blocking the interaction of a requisite c-MYC IRES trans-acting factor, heterogeneous nuclear ribonucleoprotein A1, with its IRES. Here we demonstrate that C11 also blocks cyclin D1 IRES-dependent initiation and demonstrates synergistic anti-GBM properties when combined with the mechanistic target of rapamycin kinase inhibitor PP242. The structure-activity relationship of C11 was investigated and resulted in the identification of IRES-J007, which displayed improved IRES-dependent initiation blockade and synergistic anti-GBM effects with PP242. Mechanistic studies with C11 and IRES-J007 revealed binding of the inhibitors within the UP1 fragment of heterogeneous nuclear ribonucleoprotein A1, and docking analysis suggested a small pocket within close proximity to RRM2 as the potential binding site. We further demonstrate that co-therapy with IRES-J007 and PP242 significantly reduces tumor growth of GBM xenografts in mice and that combined inhibitor treatments markedly reduce the mRNA translational state of cyclin D1 and c-MYC transcripts in these tumors. These data support the combined use of IRES-J007 and PP242 to achieve synergistic antitumor responses in GBM. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. NPAT links cyclin E-Cdk2 to the regulation of replication-dependent histone gene transcription.

    PubMed

    Zhao, J; Kennedy, B K; Lawrence, B D; Barbie, D A; Matera, A G; Fletcher, J A; Harlow, E

    2000-09-15

    In eukaryotic cells, histone gene expression is one of the major events that mark entry into S phase. While this process is tightly linked to cell cycle position, how it is regulated by the cell cycle machinery is not known. Here we show that NPAT, a substrate of the cyclin E-Cdk2 complex, is associated with human replication-dependent histone gene clusters on both chromosomes 1 and 6 in S phase. We demonstrate that NPAT activates histone gene transcription and that this activation is dependent on the promoter elements (SSCSs) previously proposed to mediate cell cycle-dependent transcription. Cyclin E is also associated with the histone gene loci, and cyclin E-Cdk2 stimulates the NPAT-mediated activation of histone gene transcription. Thus, our results both show that NPAT is involved in a key S phase event and provide a link between the cell cycle machinery and activation of histone gene transcription.

  11. Bio-pathologic characteristics related to chromosome 11 aneusomy and cyclin D1 gene status in surgically resected stage I and II breast cancer: Identification of an adverse prognostic profile.

    PubMed

    Mottolese, Marcella; Orlandi, Giulia; Sperduti, Isabella; Merola, Roberta; Buglioni, Simonetta; Di Benedetto, Anna; Pinnarò, Paola; Perracchio, Letizia; Venturo, Irene; Cognetti, Francesco; Cianciulli, AnnaMaria

    2007-02-01

    We aimed at developing a more detailed understanding of cyclin D1 in early stage human breast cancer and defining the biologic profiles with different prognostic value correlating cyclin D1 gene amplification and chromosome 11 aneusomy with bio-pathologic variables of known clinical importance. Cyclin D1 gene amplification and chromosome 11 aneusomy were investigated using fluorescence in situ hybridization whereas cyclin D1, PgR, HER-2, Bcl2, p53, and Ki-67 expressions were analyzed by immunohistochemistry in 121 stage I or II breast cancer patients uniformly treated with cyclophosphamide/metotrexate/5-fluorouracil-based chemotherapy. Cyclin D1 was amplified in 6.6% and overexpressed in 32.2% of cases. Amplification was not associated with any selected bio-pathologic variables, whereas the chromosome 11 aneusomy level significantly increased in tumors with higher histologic grade (P < 0.01), higher tumor size (P < 0.003), p53 nuclear accumulation (P < 0.04), and ERalpha negativity (P < 0.049). Multiple correspondence analysis showed 4 different biologic tumor profiles. The first, characterized by high Ki-67 score, p53+, cyclin D1+, HER-2+, aneusomy level > 30%, ratio (cyclin D1 gene/CEP11) > 2, was associated with tumor relapse defining the most unfavorable biologic profile. Kaplan-Meier's method showed significantly shorter disease-free survival in patients with at least 3 variables positive out of the 6 detected by multiple correspondence analysis. In multivariate analysis, the identified biologic profile emerged as the only significant prognostic indicator. Our findings are of particular clinical interest for early stage breast cancer patients, because the assessment of biologic factors predictive of tumor aggressiveness may influence postoperative therapeutic strategies.

  12. The pterocarpanquinone LQB-118 inhibits tumor cell proliferation by downregulation of c-Myc and cyclins D1 and B1 mRNA and upregulation of p21 cell cycle inhibitor expression.

    PubMed

    Martino, Thiago; Magalhães, Fernanda C J; Justo, Graça A; Coelho, Marsen G P; Netto, Chaquip D; Costa, Paulo R R; Sabino, Kátia C C

    2014-06-15

    The incidence of cancer grows annually worldwide and in Brazil it is the second cause of death. The search for anti-cancer drugs has then become urgent. It depends on the studies of natural and chemical synthesis products. The antitumor action of LQB-118, a pterocarpanquinone structurally related to lapachol, has been demonstrated to induce mechanisms linked to leukemia cell apoptosis. This work investigated some mechanisms of the in vitro antitumor action of LQB-118 on prostate cancer cells. LQB-118 reduced the expression of the c-Myc transcription factor, downregulated the cyclin D1 and cyclin B1 mRNA levels and upregulated the p21 cell cycle inhibitor. These effects resulted in cell cycle arrest in the S and G2/M phases and inhibition of tumor cell proliferation. LQB-118 also induced programmed cell death of the prostate cancer cells, as evidenced by internucleosomal DNA fragmentation and annexin-V positive cells. Except the cell cycle arrest in the S phase and enhanced c-Myc expression, all the mechanisms observed here for the in vitro antitumor action of LQB-118 were also found for Paclitaxel, a traditional antineoplastic drug. These findings suggest new molecular mechanisms for the LQB-118 in vitro antitumor action. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Selective usage of D-type cyclins in lymphoid malignancies.

    PubMed

    Suzuki, R; Kuroda, H; Komatsu, H; Hosokawa, Y; Kagami, Y; Ogura, M; Nakamura, S; Kodera, Y; Morishima, Y; Ueda, R; Seto, M

    1999-09-01

    Three D-type cyclins, cyclin D1, D2 and D3, belong to the G1 cyclin, which regulates the G1/S transition of the cell cycle, and feature highly homologous amino acid sequences. The cyclin D1 gene was found to be transcriptionally activated in B-lymphoid malignancies with t(11;14), but available information is limited regarding expression of cyclin D2 and D3 in hematopoietic malignancies. We examined the expressions of three D-type cyclins to investigate how these homologous genes are differentially used. Northern blot hybridization with densitometric analyses was performed to examine 64 cell lines and 159 patients with various hematopoietic malignancies. Among lymphoid malignancies, cyclin D1 overexpression was exclusively detected in B cell malignancies accompanied by a genetic event consisting of 11q13 chromosomal translocation, consisting of 13 of 19 (68%) patients with mantle cell lymphoma, two of 11 (18%) with B-chronic lymphocytic leukemia, and one of six (17%) with multiple myeloma. The cyclin D2 expression was significantly higher in T cell malignancies than in B cell malignancies (P = 0.003 for cell lines and P < 0.0001 for patient samples, respectively). In the T cell malignancies, cyclin D2 overexpression was predominantly recognized in those with mature phenotype. Furthermore, cyclin D2 expression was upregulated by phytohemagglutinin (PHA) stimulation of normal T-lymphocytes, suggesting that this simply represents the proliferation status of mature T cells. Although cyclin D3 was ubiquitously expressed, its expression was reduced in lymphoid malignancies with cyclin D1 or D2 overexpression. In myeloid leukemias, although three D-type type cyclins were differentially expressed, no preference for particular D-type cyclins was found. This selective usage of D-type cyclins in lymphoid malignancies suggests an existence of a regulatory mechanism among three D-type cyclins.

  14. OVCA1 expression and its correlation with the expression levels of cyclin D1 and p16 in cervical cancer and intraepithelial neoplasia

    PubMed Central

    Tong, Rui; Yang, Qing; Wang, Chunyan; Bi, Fangfang; Jiang, Bing

    2017-01-01

    The present study aimed to examine the associations between the protein and mRNA expression levels of ovarian cancer gene 1 (OVCA1), cyclin D1 and p16 and high-risk human papillomavirus (HR-HPV) infection in cervical lesions. The protein expression levels of OVCA1, cyclin D1 and p16 in 66 cases of cervical cancer, 64 cases of cervical intraepithelial neoplasia (CIN) and 34 normal cervix tissues were detected using immunohistochemistry. The mRNA expression levels of OVCA1, cyclin D1 and p16 in cervical cancer and normal cervix cells were detected using real-time polymerase chain reaction. The results revealed that the protein expression levels of OVCA1 increased gradually, whereas its mRNA expression levels decreased gradually, in the progression from normal cervix tissue to CIN and cervical cancer (P<0.01). In addition, significant differences in the protein expression levels of OVCA1 between low-and high-level CIN, as well as between the early and advanced stages of cervical cancer, were observed (P<0.05). No significant associations were detected between the protein and mRNA expression levels of OVCA1 and the pathological type of cervical cancer or the presence of lymph node metastasis (P>0.05). The expression levels of OVCA1 mRNA and protein were positively correlated with the levels of p16 expression (P<0.01). Significant differences were also observed in the OVCA1 protein and mRNA expression levels between the HR-HPV (+) and HR-HPV (−) groups (P<0.05). Therefore, aberrant expression of OVCA1 protein and mRNA may be important during the development of cervical lesions, particularly in the early stages. In addition, the mechanisms underlying the effects of OVCA1 during cervical cancer development may involve p16 and HPV, as the levels of OVCA1 in cervical lesions were correlated with abnormal expression of p16 and HR-HPV infection. PMID:28521400

  15. OVCA1 expression and its correlation with the expression levels of cyclin D1 and p16 in cervical cancer and intraepithelial neoplasia.

    PubMed

    Tong, Rui; Yang, Qing; Wang, Chunyan; Bi, Fangfang; Jiang, Bing

    2017-05-01

    The present study aimed to examine the associations between the protein and mRNA expression levels of ovarian cancer gene 1 (OVCA1), cyclin D1 and p16 and high-risk human papillomavirus (HR-HPV) infection in cervical lesions. The protein expression levels of OVCA1, cyclin D1 and p16 in 66 cases of cervical cancer, 64 cases of cervical intraepithelial neoplasia (CIN) and 34 normal cervix tissues were detected using immunohistochemistry. The mRNA expression levels of OVCA1, cyclin D1 and p16 in cervical cancer and normal cervix cells were detected using real-time polymerase chain reaction. The results revealed that the protein expression levels of OVCA1 increased gradually, whereas its mRNA expression levels decreased gradually, in the progression from normal cervix tissue to CIN and cervical cancer (P<0.01). In addition, significant differences in the protein expression levels of OVCA1 between low-and high-level CIN, as well as between the early and advanced stages of cervical cancer, were observed (P<0.05). No significant associations were detected between the protein and mRNA expression levels of OVCA1 and the pathological type of cervical cancer or the presence of lymph node metastasis (P>0.05). The expression levels of OVCA1 mRNA and protein were positively correlated with the levels of p16 expression (P<0.01). Significant differences were also observed in the OVCA1 protein and mRNA expression levels between the HR-HPV (+) and HR-HPV (-) groups (P<0.05). Therefore, aberrant expression of OVCA1 protein and mRNA may be important during the development of cervical lesions, particularly in the early stages. In addition, the mechanisms underlying the effects of OVCA1 during cervical cancer development may involve p16 and HPV, as the levels of OVCA1 in cervical lesions were correlated with abnormal expression of p16 and HR-HPV infection.

  16. Immortalization of Fetal Bovine Colon Epithelial Cells by Expression of Human Cyclin D1, Mutant Cyclin Dependent Kinase 4, and Telomerase Reverse Transcriptase: An In Vitro Model for Bacterial Infection

    PubMed Central

    Kuroda, Kengo; Kiyono, Tohru; Isogai, Emiko; Masuda, Mizuki; Narita, Moe; Okuno, Katsuya; Koyanagi, Yukako; Fukuda, Tomokazu

    2015-01-01

    Cattle are the economically important animals in human society. They are essential for the production of livestock products such as milk and meats. The production efficiency of livestock products is negatively impacted by infection with zoonotic pathogens. To prevent and control infectious diseases, it is important to understand the interaction between cattle tissue and pathogenic bacteria. In this study, we established an in vitro infection model of an immortalized bovine colon-derived epithelial cell line by transducing the cells with lentiviral vectors containing genes encoding cell cycle regulators cyclin D1, mutant cyclin dependent kinase 4 (CDK4), and human telomerase reverse transcriptase (TERT). The established cell line showed continuous cell proliferation, expression of epithelial markers, and an intact karyotype, indicating that the cells maintained their original nature as colon-derived epithelium. Furthermore, we exposed the established cell line to two strains of Salmonella enterica and EHEC. Interestingly, S. Typhimurium showed higher affinity for the established cell line and invaded the cytoplasm than S. Enteritidis. Quantitative RT-PCR revealed that gene expression of Toll-like receptor 1 (TLR1), TLR 2 and TLR 3, whereas TLR 4, 5 and 6 were not detectable in established cells. Our established immortalized colon-derived epithelial cell should be a useful tool for studies evaluating the molecular mechanisms underlying bacterial infection. PMID:26624883

  17. Unusual concomitant rearrangements of Cyclin D1 and MYC genes in blastoid variant of mantle cell lymphoma: Case report and review of literature.

    PubMed

    Delas, Audrey; Sophie, Dobbelstein; Brousset, Pierre; Laurent, Camille

    2013-02-15

    We report herein a case of blastoid variant mantle cell lymphoma (MCL) with both aberrant phenotype and unusual genetics. Unexpectedly, lymphoma cells were CD5(-) and CD10(+). Standard karyotype and FISH techniques showed that tumor cells carried two distinct translocations which had not been reported together in a same tumor. The first translocation juxtaposed the immunoglobulin lambda light chain locus with CCND1 locus, leading to Cyclin D1 overexpression. The second translocation revealed MYC rearrangement with a non-immunoglobulin gene partner located on the short arm of chromosome 4. The interpretation of the case on tissue sections alone could have been challenging. Indeed, the lack of CD5 and expression of CD10 associated with MYC rearrangement detected on interphasic nuclei could support the diagnosis of diffuse large B-cell lymphoma or Burkitt lymphoma. This distinction is also especially important as these lymphoma subtypes require specific treatment. Copyright © 2012 Elsevier GmbH. All rights reserved.

  18. Association of ICAM-1, VCAM-1, CYCLIN D1 and Cathepsin D with Clinicopathological Parameters in Breast Carcinoma; an Immunohistochemical Study

    PubMed Central

    Külahcı, Özgür; Esen, H. Hasan; Asut, Elife; Güngör, Salim

    2017-01-01

    Objective Breast carcinoma is the most common malignant tumor detected in women. The hypothesis that increased levels of adhesion molecules and Cathepsin D affect cancerous cells moving away the primary tumor and contributes to migration of the cancerous cell and may cause remote organ metastases is defended. The aim of the present study was to search the association of intracellular adhesion molecule-1 (ICAM-1), vascular adhesion molecule-1 (VCAM-1), Cyclin D1, cathepsin D immunohistochemically with clinicopathological parameters in the patients diagnosed with invasive ductal breast carcinoma. Materials and Methods The pathological slides of 153 patients diagnosed with invasive ductal carcinoma were evaluated retrospectively. Three groups were created. Group 1 consisted of patients with positive lymph node metastasis and extranodal tumor invasion; Group 2 consisted of patients with positive axillary lymph node metastasis and negative extranodal tumor invasion and Group 3 consisted of the patients with negative axillary lymph node metastasis. In all groups, 20 paraffin blocks belonging to the primary tumor in the breast were stained by ICAM-1, VCAM-1, Cyclin D1 and Cathepsin D. Findings were examined by comparing with clinicopathological parameters. Results The highest number of metastatic axillary lymph nodes and the highest rate of cathepsin D staining were statistically found in the cases with positive axillary lymph node metastasis and extranodal tumor invasion. CerbB2 was negative in the cases with negative ICAM-1 whereas estrogen receptor and progesterone receptor were positive in the cases with positive VCAM-1. Conclusion The present study reveals significant results for the patients diagnosed with invasive ductal carcinoma through breast biopsy especially before mastectomy in terms of increased number of metastatic axillary lymph nodes and extranodal tumor invasion by immunohistochemical Cathepsin D stain without any additional invasive intervention

  19. Methylation of CpG islands of p16(INK4a) and cyclinD1 overexpression associated with progression of intraductal proliferative lesions of the breast.

    PubMed

    Liu, Tieju; Niu, Yun; Feng, Yumei; Niu, Ruifang; Yu, Yong; Lv, Ajuan; Yang, Yi

    2008-11-01

    P16(INK4a) is a tumor suppressor gene frequently inactivated by aberrant promoter hypermethylation. In this study, p16(INK4a) methylation was evaluated in intraductal proliferative lesions of the breast, using real-time quantitative polymerase chain reaction (MethyLight) and methylation-sensitive restriction endonuclease polymerase chain reaction. Immunohistochemistry was performed to compare and validate the methylation analysis. P16(INK4a) methylation associated with oncogene cyclinD1 expression, detected through the use of in situ hybridization and immunohistochemistry, was likewise characterized. P16(INK4a) methylation displayed varying significance among different types of intraductal proliferative lesions. Both the positive rate and the median quantitative methylation value increased with the evolution of intraductal proliferative lesions through the use of quantitative and qualitative assays. P16(INK4a) methylation was positively correlated to cyclinD1 overexpression. This study demonstrated that p16(INK4a) methylation served as the silencing mechanism of p16(INK4a) protein expression and played a crucial role in the intraductal proliferative lesions' progression. In the differential diagnosis of intraductal proliferative lesions, quantitative DNA methylation analysis of p16(INK4a) by MethyLight may be used as a surrogate, especially to distinguish atypical ductal hyperplasia from usual ductal hyperplasia and low-grade ductal carcinoma in situ. Furthermore, this study discovered that flat epithelial atypia do not share similar molecular profiles of p16(INK4a) epigenetic modification with atypical ductal hyperplasia and low-grade ductal carcinoma in situ.

  20. 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.

  1. Abrogation of p53 by its antisense in MCF-7 breast carcinoma cells increases cyclin D1 via activation of Akt and promotion of cell proliferation

    SciTech Connect

    Chhipa, Rishi Raj; Kumari, Ratna; Upadhyay, Ankur Kumar; Bhat, Manoj Kumar

    2007-11-15

    The p53 protein has been a subject of intense research interest since its discovery as about 50% of human cancers carry p53 mutations. Mutations in the p53 gene are the most frequent genetic lesions in breast cancers suggesting a critical role of p53 in breast cancer development, growth and chemosensitivity. This report describes the derivation and characterization of MCF-7As53, an isogenic cell line derived from MCF-7 breast carcinoma cells in which p53 was abrogated by antisense p53 cDNA. Similar to MCF-7 and simultaneously selected hygromycin resistant MCF-7H cells, MCF-7As53 cells have consistent basal epithelial phenotype, morphology, and estrogen receptor expression levels at normal growth conditions. Present work documents investigation of molecular variations, growth kinetics, and cell cycle related studies in relation to absence of wild-type p53 protein and its transactivation potential as well. Even though wild-type tumor suppressor p53 is an activator of cell growth arrest and apoptosis-mediator genes such as p21, Bax, and GADD45 in MCF-7As53 cells, no alterations in expression levels of these genes were detected. The doubling time of these cells decreased due to depletion of G0/G1 cell phase because of constitutive activation of Akt and increase in cyclin D1 protein levels. This proliferative property was abrogated by wortmannin, an inhibitor of PI3-K/Akt signaling pathway. Therefore this p53 null cell line indicates that p53 is an indispensable component of cellular signaling system which is regulated by caveolin-1 expression, involving Akt activation and increase in cyclin D1, thereby promoting proliferation of breast cancer cells.

  2. BRAF inhibitor therapy-associated melanocytic lesions lack the BRAF V600E mutation and show increased levels of cyclin D1 expression.

    PubMed

    Mudaliar, Kumaran; Tetzlaff, Michael T; Duvic, Madeleine; Ciurea, Ana; Hymes, Sharon; Milton, Denái R; Tsai, Kenneth Y; Prieto, Victor G; Torres-Cabala, Carlos A; Curry, Jonathan L

    2016-04-01

    Newly appearing or changing melanocytic lesions (MLs) are a recently reported toxicity of BRAF inhibitor (BRAFi) therapy. Morphologically, MLs associated with BRAFi therapy (BRAFi-MLs) may demonstrate alarming features of melanoma with an epithelioid cell phenotype with notable cytologic atypia. We sought to characterize the clinicopathological and molecular features of BRAFi-MLs. A retrospective review over a 4-year period revealed 20 patients in which 44 MLs (including 11 control nevi) were characterized by histopathology, review of clinical medical records, and immunohistochemical (IHC) studies (with anti-BRAF V600E, anti-BAP1, anti-cyclin D1, and anti-p16); the percentage of IHC+ cells was scored. Of the 20 patients, 3 (15%) whose BRAFi-MLs were biopsied had a second primary cutaneous melanoma. Of the 44 BRAFi-MLs tested, 37 (100%) of 37 MLs available for BRAF V600E testing lacked expression in contrast to 1 (9%) of 11 control nevi (lesions not associated with targeted therapy). A significantly higher level of cyclin D1 expression (>50% IHC+ cells) was more commonly seen in BRAFi-MLs (44%) than in control nevi (9%). No difference in p16 expression in melanocytes was seen between the 2 groups. BRAF mutation status distinctly differs between BRAFi-MLs from melanomas and nevi biopsied in patients who do not receive BRAFi therapy. Morphologically, BRAFi-MLs demonstrate a greater degree of atypia than do control nevi. Furthermore, BRAFi-MLs with coexisting cutaneous keratinocyte toxicity developed during fewer days of targeted therapy. Paradoxical activation of the MAPK pathway in BRAF(WT) melanocytes may account for ~15% to 21% of patients developing a second new primary melanoma within a year of starting BRAFi therapy; thus, close clinical surveillance is warranted. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. 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.

  4. FTY720 Shows Promising In vitro and In vivo Preclinical Activity by Downmodulating Cyclin D1 and Phospho-Akt in Mantle Cell Lymphoma

    PubMed Central

    Liu, Qing; Alinari, Lapo; Chen, Ching-Shih; Yan, Fengting; Dalton, James T.; Lapalombella, Rosa; Zhang, Xiaoli; Mani, Rajeswaran; Lin, Teresa; Byrd, John C.; Baiocchi, Robert A.; Muthusamy, Natarajan

    2014-01-01

    Purpose Despite the progress that has been made in the treatment of mantle cell lymphoma (MCL), all patients invariably relapse with the currently available therapies. Because of the absence of curative therapy for MCL, we explored FTY720 as a novel agent against MCL. Experimental Design The cytotoxic effect of FTY720 in primary MCL tumor cells and cell lines were evaluated in vitro. The effects of FTY720 on caspase activation, generation of reactive oxygen species, and modulation of Cyclin D1 and Akt, which are implied in the pathogenesis of MCL, were investigated. The in vivo efficacy of FTY720 was evaluated in a Jeko-severe combined immunodeficient xenograft model of human MCL. Results FTY720 mediated time- and dose-dependent cytotoxicity in primary MCL tumor cells and MCL cell lines in vitro. FTY720-induced cytotoxicity occured independent of caspase activation but dependent on the generation of ROS in MCL. In addition, FTY720 treatment resulted in the time-dependent downmodulation of Cyclin D1 and accumulation of cells in G0-G1 and G2-M phases of the cell cycle with concomitant decrease in S-phase entry. Furthermore, concentrations of FTY720 that induced cytotoxicity led to decreased phospho-Akt in primary MCL cells and cell lines. Most importantly, the in vivo therapeutic activity of FTY720 was shown in severe combined immunodeficient mice engrafted with the Jeko MCL cell line. Conclusions These results provide the first evidence for a potential use of FTY720 in targeting key pathways that are operable in the pathogenesis of MCL and warrant further investigation of FTY720 in clinical trials to treat patients with MCL. PMID:20460491

  5. 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

    Meta. Doslidyty zminy rivniv Cyclin D1+ klityn ta asotsiyovanykh geniv CCND1 ta PNKP u mononuklearakh peryfe rychnoI krovi v uchasnykiv likvidatsiI naslidkiv avariI (ULNA) na ChAES z riznym imunnym statusom v zalezhnosti vid dozy oprominennia.Materialy i metody. Proanalizovano vidnosnyy riven' Cyclin D1+ klityn u mononuklearakh peryferychnoI krovi 39 ULNA na ChAES, cholovikiv, oprominenykh u dozi u diapazoni (0,01–2,00) Gr. Imunologichnyy status obstezhenykh vyz nachavsia za rivnem CD3/19, CD4/8, CD3/HLA DR, SD3/16/56 metodom protochnoI tsytofluorymetriI ta za vmistom Ig klasiv A,M,G metodom imunofermentnogo analizu u krovi. Ekspresiia geniv CCND1 ta PNKP, iaki pov’iazani z Syclin D1, provodylos' za metodom polimeraznoI lantsiugovoI reaktsiI u real'nomu chasi. Porivniannia rezul'tativ zdiysniuva los' iz vidpovidnymy danymy, otrymanymy vid 18 zdorovykh cholovikiv, iaki ne maly kontaktu z ionizuiuchym vyp rominiuvanniam vyshche pryrodn'ogo fonu.Rezul'taty. Pokazano, shcho vidsotok Suclin D1+ klityn zbil'shuiet'sia za normu v osib, oprominenykh u dozi > 0,1 Gr, ta koreliuie z dozoiu oprominennia (rs = 0,417, p = 0,048). Vidkhylennia rivnia Cyclin D1+ klityn za mezhi kontrol'nykh zna chen' pov’iazuiet'sia zi zminamy v klitynniy ta gumoral'niy lankakh imunitetu. Zmenshennia vidsotku Cyclin D1+ klityn za mezhi kontrol'nykh znachen' v ULNA na ChAES iz dozoiu < 0,35 Gr suprovodzhuiet'sia znyzhenniam rivniv CD3+ ta pidvy shchenniam CD3 16+56+ limfotsytiv; u osib, oprominenykh u dozi > 0,35 Gr, zbil'shennia vidsotku Cyclin D1+ klityn asotsiiuiet'sia zi znyzhenniam CD3+ ta tendentsiieiu shchodo znyzhennia CD3+16+56+ limfotsytiv u poiednanni zi zbil'shen niam rivnia IgG. Zbil'shennia rivniv CD4+, CD19+, Ireg. ta IgG suprovodzhuiet'sia poiavoiu koreliatsiynykh zv’iazkiv mizh Cyclin D1+ ta CD3 16+56+ klitynamy (rs = 0,872, p = 0,049), Cyclin D1+ ta CD8+ i IgG (rs = 0,683, p = 0,042; rs = 0,809, p = 0,014), Cyclin D1+ ta CD4+ (rs = 0,602, p = 0,029), Cyclin D1+ ta CD19+ i

  6. Increased papillae growth and enhanced short-chain fatty acid absorption in the rumen of goats are associated with transient increases in cyclin D1 expression after ruminal butyrate infusion.

    PubMed

    Malhi, Moolchand; Gui, Hongbing; Yao, Lei; Aschenbach, Jörg R; Gäbel, Gotthold; Shen, Zanming

    2013-01-01

    We tested the hypothesis that the proliferative effects of intraruminal butyrate infusions on the ruminal epithelium are linked to upregulation in cyclin D1 (CCND1), the cyclin-dependent kinase 4 (CDK4), and their possible association with enhanced absorption of short-chain fatty acids (SCFA). Goats (n=23) in 2 experiments (Exp.) were fed 200 g/d concentrate and hay ad libitum. In Exp. 1, goats received an intraruminal infusion of sodium butyrate at 0.3 (group B, n=8) or 0 (group C, n=7) g/kg of body weight (BW) per day before morning feeding for 28 d and were slaughtered 8 h after the butyrate infusion. In Exp. 2, goats (n=8) received butyrate infusion and feeding as in Exp. 1. On d 28, epithelial samples were biopsied from the antrium ruminis at 0, 3, and 7 h after the last butyrate infusion. In Exp. 1, the ruminal molar proportional concentration of butyrate increased in group B by about 110% after butyrate infusion and remained elevated for 1.5 h; thereafter, it gradually returned to the baseline (preinfusion) level. In group C, the molar proportional concentration of butyrate was unchanged over the time points. The length and width of papillae increased in B compared with C; this was associated with increased numbers of cells and cell layers in the epithelial strata and an increase in the surface area of 82%. The mRNA expression of CCND1 increased transiently at 3 h but returned to the preinfusion level at 7 h following butyrate infusion in Exp. 2. However, it did not differ between B and C in Exp. 1, in which the ruminal epithelium was sampled at 8 h after butyrate infusion. The mRNA expression of the monocarboxylate transporter MCT4, but not MCT1, was stably upregulated in B compared with C. The estimated absorption rate of total SCFA (%/h) increased in B compared with C. We conclude that transient increases in cyclin D1 transcription contribute to butyrate-induced papillae growth and subsequently to the increased absorption of SCFA in the ruminal epithelium

  7. Regulation of modular Cyclin and CDK feedback loops by an E2F transcription oscillator in the mammalian cell cycle.

    PubMed

    Lavi, Orit; Ginsberg, Doron; Louzoun, Yoram

    2011-04-01

    The cell cycle is regulated by a large number of enzymes and transcription factors. We have developed a modular description of the cell cycle, based on a set of interleaved modular feedback loops, each leading to a cyclic behavior. The slowest loop is the E2F transcription and ubiquitination, which determines the cycling frequency of the entire cell cycle. Faster feedback loops describe the dynamics of each Cyclin by itself. Our model shows that the cell cycle progression as well as the checkpoints of the cell cycle can be understood through the interactions between the main E2F feedback loop and the driven Cyclin feedback loops. Multiple models were proposed for the cell cycle dynamics; each with differing basic mechanisms. We here propose a new generic formalism. In contrast with existing models, the proposed formalism allows a straightforward analysis and understanding of the dynamics, neglecting the details of each interaction. This model is not sensitive to small changes in the parameters used and it reproduces the observed behavior of the transcription factor E2F and different Cyclins in continuous or regulated cycling conditions. The modular description of the cell cycle resolves the gap between cyclic models, solely based on protein-protein reactions and transcription reactions based models. Beyond the explanation of existing observations, this model suggests the existence of unknown interactions, such as the need for a functional interaction between Cyclin B and retinoblastoma protein (Rb) de-phosphorylation.

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

    SciTech Connect

    Li Chenchen Xing Tairan Tang Mingliang Yong Wu Yan Dan Deng Hongmin Wang Huili Wang Ming Chen Jutao Ruan Diyun

    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 neuronal 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.

  9. Cyclin Y-mediated transcript profiling reveals several important functional pathways regulated by Cyclin Y in hippocampal neurons

    PubMed Central

    Kim, Hanna; Hong, Jung-Hwa; Kim, Mirang; Park, Mikyoung

    2017-01-01

    Cyclin Y (CCNY), which is a cyclin protein known to play a role in cell division, is unexpectedly and thus interestingly expressed in non-proliferating neuronal cells. There have been only a few studies reporting the neuronal functions of CCNY in synapse remodeling and hippocampal long-term potentiation. Therefore, we here provide global and comprehensive information on the putative functions of CCNY in biological and functional pathways in neuronal systems. We adopted high-throughput RNA-sequencing technology for analyzing transcriptomes regulated by CCNY and utilized bioinformatics for identifying putative molecules, biological processes, and functional pathways that are possibly connected to CCNY functions in hippocampal neuronal cells of rats. We revealed that several enriched annotation terms and pathways associated with CCNY expression within neurons, including apoptosis, learning or memory, synaptic plasticity, actin cytoskeleton, focal adhesion, extracellular matrix-receptor interaction and chemokine signaling pathway are targeted by CCNY. In addition, the mRNA levels of some genes enriched for those annotation terms and pathways or genes reported to be altered in Alzheimer’s disease mouse model were further validated by quantitative real-time PCR in hippocampal neuronal cells. The present study provides an excellent resource for future investigations of CCNY functions in neuronal systems. PMID:28241067

  10. Opposing roles for DNA replication initiator proteins ORC1 and CDC6 in control of Cyclin E gene transcription

    PubMed Central

    Hossain, Manzar; Stillman, Bruce

    2016-01-01

    Newly born cells either continue to proliferate or exit the cell division cycle. This decision involves delaying expression of Cyclin E that promotes DNA replication. ORC1, the Origin Recognition Complex (ORC) large subunit, is inherited into newly born cells after it binds to condensing chromosomes during the preceding mitosis. We demonstrate that ORC1 represses Cyclin E gene (CCNE1) transcription, an E2F1 activated gene that is also repressed by the Retinoblastoma (RB) protein. ORC1 binds to RB, the histone methyltransferase SUV39H1 and to its repressive histone H3K9me3 mark. ORC1 cooperates with SUV39H1 and RB protein to repress E2F1-dependent CCNE1 transcription. In contrast, the ORC1-related replication protein CDC6 binds Cyclin E-CDK2 kinase and in a feedback loop removes RB from ORC1, thereby hyper-activating CCNE1 transcription. The opposing effects of ORC1 and CDC6 in controlling the level of Cyclin E ensures genome stability and a mechanism for linking directly DNA replication and cell division commitment. DOI: http://dx.doi.org/10.7554/eLife.12785.001 PMID:27458800

  11. Cell cycle-dependent regulation of the forkhead transcription factor FOXK2 by CDK·cyclin complexes.

    PubMed

    Marais, Anett; Ji, Zongling; Child, Emma S; Krause, Eberhard; Mann, David J; Sharrocks, Andrew D

    2010-11-12

    Several mammalian forkhead transcription factors have been shown to impact on cell cycle regulation and are themselves linked to cell cycle control systems. Here we have investigated the little studied mammalian forkhead transcription factor FOXK2 and demonstrate that it is subject to control by cell cycle-regulated protein kinases. FOXK2 exhibits a periodic rise in its phosphorylation levels during the cell cycle, with hyperphosphorylation occurring in mitotic cells. Hyperphosphorylation occurs in a cyclin-dependent kinase (CDK)·cyclin-dependent manner with CDK1·cyclin B as the major kinase complex, although CDK2 and cyclin A also appear to be important. We have mapped two CDK phosphorylation sites, serines 368 and 423, which play a role in defining FOXK2 function through regulating its stability and its activity as a transcriptional repressor protein. These two CDK sites appear vital for FOXK2 function because expression of a mutant lacking these sites cannot be tolerated and causes apoptosis.

  12. In vivo study on the effects of curcumin on the expression profiles of anti-tumour genes (VEGF, CyclinD1 and CDK4) in liver of rats injected with DEN.

    PubMed

    Huang, Chu Zhu; Huang, Wei Zhe; Zhang, Ge; Tang, Dan Ling

    2013-10-01

    In this study we investigated the effects of curcumin, derived from plant Curcuma longa, on oxidative toxicity, and the possible molecular mechanism of antitumour of curcumin in liver cancer rats. Results showed that blood levels of Gamma-glutamyltransferase, aspartate aminotransferase, alanine aminotransferase, glutathione S-transferase, and liver level of MD were significantly decreased after curcumin feeding. Levels of the liver malondialdehyde MDA, nitric oxide and antioxidant enzymes were significantly increased. Moreover, RT-PCR and Western blot analysis results showed that curcumin treatment significantly decreased liver vascular endothelial growth factor (VEGF), CyclinD1 and CDK4 mRNA expression levels and CyclinD1 and CDK4 proteins levels in liver cancer rats. These findings were confirmed by histopathology. It is concluded that curcumin can protect the liver from the damage caused by N-nitrosodiethylamine. Moreover, curcumin has the potential to be used in a therapy for liver cancer. The present data provide evidence to support the presence of free radicals and VEGF, CyclinD1 and CDK4 mRNA in rat tumour cells. Studies are in progress in order to further characterize the role of VEGF, CyclinD1 and CDK4 mRNA in liver cancer cells and in hepatic therapeutics.

  13. The Freud-1/CC2D1A family: transcriptional regulators implicated in mental retardation.

    PubMed

    Rogaeva, Anastasia; Galaraga, Kimberly; Albert, Paul R

    2007-10-01

    The CC2D1A gene family consists of two homologous genes, Freud-1/CC2D1A and Freud-2/CC2D1B, that share conserved domains, including several DM14 domains that are specific to this protein family, a C-terminal helix-loop-helix domain, and a C2 calcium-dependent phospholipid binding domain. Although the function of Freud-2 is unknown, Freud-1 has been shown to function as a transcriptional repressor of the serotonin-1A receptor gene that binds to a novel DNA element (FRE, 5'-repressor element). The DNA binding and repressor activities of Freud-1 are inhibited by calcium-calmodulin-dependent protein kinase. Recently, a deletion in the CC2D1A gene has been linked to nonsyndromic mental retardation. This deletion results in the truncation of the helix-loop-helix DNA binding and the C2 domains, crucial for Freud-1 repressor activity, and hence is predicted to generate an inactive or weakly dominant negative protein. The possible mechanisms by which inactivation of Freud-1 could lead to abnormal cortical development and cognitive impairment and the potential roles of Freud-1 gene targets are discussed.

  14. The high expression of TC1 (C8orf4) was correlated with the expression of β-catenin and cyclin D1 and the progression of squamous cell carcinomas of the tongue.

    PubMed

    Zhang, Peng; Cao, Hong-Yi; Bai, Lin-Lin; Li, Wei-Nan; Wang, Yuan; Chen, Song-Yan; Zhang, Li; Yang, Lian-He; Xu, Hong-Tao; Wang, En-Hua

    2015-09-01

    Thyroid cancer 1 (TC1, C8orf4) plays important roles in many signaling pathways, such as Wnt/β-catenin signaling pathway, and is involved in the development of many cancers. The objective of this study was to examine the expression of TC1 and investigate the associations among TC1, β-catenin, Chibby, cyclin D1, and the clinicopathological factors of oral tongue squamous cell carcinomas (OTSCCs). The expressions of TC1, β-catenin, Chibby, and cyclin D1 were examined in 109 cases of OTSCCs using immunohistochemistry. The expression of TC1 was observed in all cases of OTSCCs but was negative or weak in normal squamous epithelial tissues of tongue. The high expression of TC1 was correlated with the advanced TNM stage (P = 0.042), the abnormal expression of β-catenin (correlation coefficient = 0.314, P = 0.001) and the expression of cyclin D1 (correlation coefficient = 0.274, P = 0.006) in OTSCCs. But we did not find any associations between TC1 and Chibby. The abnormal expression of β-catenin was correlated with the poor differentiation (P = 0.035), advanced TNM stage (P = 0.048) and the expression of cyclin D1 (correlation coefficient = 0.422, P < 0.001). In conclusion, the high expression of TC1 was common in OTSCCs and correlated with the expression of β-catenin and cyclin D1 and the progression of OTSCCs. The high expression level of TC1 might promote the progression of OTSCCs by enhancing the activity of Wnt signaling pathway.

  15. [Retracted] Epidermal growth factor-stimulated human cervical cancer cell growth is associated with EGFR and cyclin D1 activation, independent of COX-2 expression levels.

    PubMed

    Narayanan, Rajkishen; Kim, Hye Na; Narayanan, Narayanan K; Nargi, Dominick; Narayanan, Bhagavathi

    2017-01-01

    Following the publication of this article, which was concerned with the expression of phosphorylated epidermal growth factor receptor (pEGFR) and cyclin D1 activation independently of the expression levels of cyclo-oxygenase-2, an interested reader drew to our attention apparent anomalies associated with the western blot data shown in Fig. 2C. Following an internal investigation at the New York University School of Medicine, we were requested to produce the original film, or the scan of the image of the film, for verification. Unfortunately, we were unable to provide the original film or scanned image to disprove the allegation, since the original pEGFR image could not be found. Therefore, the Investigation Committee recommended that this article be retracted, and we are withdrawing the article in line with the request. All the authors agree to the retraction of this paper. We sincerely regret any inconvenience this has caused. [the original article was published in the International Journal of Oncology 40: 13-20, 2012; DOI: 10.3892/ijo.2011.1211].

  16. The risk factor of gallbladder cancer: hyperplasia of mucous epithelium caused by gallstones associates with p16/CyclinD1/CDK4 pathway.

    PubMed

    Feng, Zhiqiang; Chen, Jinglong; Wei, Honglian; Gao, Ping; Shi, Jingsen; Zhang, Jinqian; Zhao, Fenglin

    2011-10-01

    The mucosa of gallbladder stimulated with gallstones and accompanied with abnormalities in bile composition, is the origin of biliary disease, which could induce metaplasia, simple hyperplasia, atypical hyperplasia and even carcinoma in situ and invasive carcinoma in gallbladder mucosa. To determine the disorder of the balance between cell proliferation and cell cycle or apoptosis in gallbladder cancer accompanied with gallstones, removal of the gallbladder due to gallstones specimens of 88 cases were collected randomly, including a variety of 54 cases for hyperplasia, 27 cases for gallbladder cancer and 7 cases for normal gallbladder. The expressions of key cell cycle factors were detected by in situ hybridization, immunohistochemistry and Western blot. The expressions of CDK4 and Cyclin D1 increased along with progression of gallbladder mucosa hyperplasia; and showed highest expression in cancer group. On the contrary, p16 decreased to the lowest level in gallbladder cancer. The increased apoptotic index analyzed by TUNEL assay rose along with malignant degree to the highest level in undifferentiated carcinoma. Our results suggest that changes of these signals have effect on breaking the balance of proliferation and death of gallbladder epithelial cells, even on inducing gallbladder cancer. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. [Ru(pipe)(dppb)(bipy)]PF6: A novel ruthenium complex that effectively inhibits ERK activation and cyclin D1 expression in A549 cells.

    PubMed

    Ferreira-Silva, Guilherme A; Ortega, Marina M; Banionis, Marco A; Garavelli, Graciana Y; Martins, Felipe T; Dias, Julia S M; Viegas, Cláudio; Oliveira, Jaqueline C de; Nascimento, Fabio B do; Doriguetto, Antonio C; Barbosa, Marilia I F; Ionta, Marisa

    2017-10-01

    Lung cancer is the most frequent type of cancer worldwide. In Brazil, only 14% of the patients diagnosed with lung cancer survived 5years in the last decades. Although improvements in the therapeutic approach, it is relevant to identify new chemotherapeutic agents. In this framework, ruthenium metal compounds emerge as a promising alternative to platinum-based compounds once they displayed lower cytotoxicity and more selectivity for tumor cells. The present study aimed to evaluate the antitumor potential of innovative ruthenium(II) complex, [Ru(pipe)(dppb)(bipy)]PF6 (PIPE) on A549 cells, which is derived from non-small cell lung cancer. Results demonstrated that PIPE effectively reduced the viability and proliferation rate of A549 cells. When PIPE was used at 9μM there was increase in G0/G1 cell population with concomitant reduction in frequency of cells in S-phase, indicating cell cycle arrest in G1/S transition. Antiproliferative activity of PIPE was associated to its ability of reducing cyclin D1 expression and ERK phosphorylation levels. Cytotoxic activity of PIPE on A549 cells was observed when PIPE was used at 18μM, which was associated to its ability of inducing apoptosis by intrinsic pathway. Taken together, the data demonstrated that PIPE is a promising antitumor agent and further in vivo studies should be performed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Cyclin C regulates adipogenesis by stimulating transcriptional activity of CCAAT/enhancer binding protein alpha.

    PubMed

    Song, Ziyi; Xiaoli, Alus M; Zhang, Quanwei; Zhang, Yi; Yang, Ellen S T; Wang, Sven; Chang, Rui; Zhang, Zhengdong D; Yang, Gongshe; Strich, Randy; Pessin, Jeffrey E; Yang, Fajun

    2017-03-28

    Brown adipose tissue (BAT) is important for maintaining energy homeostasis and adaptive thermogenesis in rodents and humans. As disorders arising from dysregulated energy metabolism, such as obesity and metabolic diseases, have increased, so has interest in the molecular mechanisms in adipocyte biology. Using a functional screen, we identified cyclin C (CycC), a conserved subunit of the Mediator complex, as a novel regulator for brown adipocyte formation. siRNA-mediated CycC knockdown (KD) in brown preadipocytes impaired the early transcriptional program of differentiation, and genetic knockout (KO) of CycC completely blocked the differentiation process. RNA-seq analyses of CycC-KD revealed a critical role of CycC in activating genes co-regulated by peroxisome proliferator activated receptor gamma (PPARγ) and CCAAT/enhancer binding protein alpha (C/EBPα). Overexpression of PPARγ2 or addition of the PPARγ ligand rosiglitazone rescued the defects in CycC-KO brown preadipocytes, and efficiently activated the PPARγ-responsive promoters in both wild-type (WT) and CycC-KO cells, suggesting that CycC is not essential for PPARγ transcriptional activity. In contrast, CycC-KO significantly reduced C/EBPα-dependent gene expression. Unlike for PPARγ, overexpression of C/EBPα could not induce C/EBPα target gene expression in CycC-KO cells or rescue the CycC-KO defects in brown adipogenesis, suggesting that CycC is essential for C/EBPα-mediated gene activation. CycC physically interacted with C/EBPα and this interaction was required for C/EBPα transactivation domain activity. Consistent with the role of C/EBPα in white adipogenesis, CycC-KD also inhibited differentiation of 3T3-L1 cells into white adipocytes. Together, these data indicate that CycC activates adipogenesis by stimulating the transcriptional activity of C/EBPα.

  19. Simultaneous expression analysis of vitamin D receptor, calcium-sensing receptor, cyclin D1, and PTH in symptomatic primary hyperparathyroidism in Asian Indians.

    PubMed

    Varshney, Shweta; Bhadada, Sanjay Kumar; Saikia, Uma Nahar; Sachdeva, Naresh; Behera, Arunanshu; Arya, Ashutosh Kumar; Sharma, Sadhna; Bhansali, Anil; Mithal, Ambrish; Rao, Sudhaker D

    2013-07-01

    To explore underlying molecular mechanisms in the pathogenesis of symptomatic sporadic primary hyperparathyroidism (PHPT). Forty-one parathyroid adenomas from patients with symptomatic PHPT and ten normal parathyroid glands either from patients with PHPT (n=3) or from euthyroid patients without PHPT during thyroid surgery (n=7) were analyzed for vitamin D receptor (VDR), calcium-sensing receptor (CASR), cyclin D1 (CD1), and parathyroid hormone (PTH) expressions. The protein expressions were assessed semiquantitatively by immunohistochemistry, based on percentage of positive cells and staining intensity, and confirmed by quantitative real-time PCR. Immunohistochemistry revealed significant reductions in VDR (both nuclear and cytoplasmic) and CASR expressions and significant increases in CD1 and PTH expressions in adenomatous compared with normal parathyroid tissue. Consistent with immunohistochemistry findings, both VDR and CASR mRNAs were reduced by 0.36- and 0.45-fold change (P<0.001) and CD1 and PTH mRNAs were increased by 9.4- and 17.4-fold change respectively (P<0.001) in adenomatous parathyroid tissue. PTH mRNA correlated with plasma PTH (r=0.864; P<0.001), but not with adenoma weight, while CD1 mRNA correlated with adenoma weight (r=0.715; P<0.001). There were no correlations between VDR and CASR mRNA levels and serum Ca, plasma intact PTH, or 25-hydroxyvitamin D levels. In addition, there was no relationship between the decreases in VDR and CASR mRNA expressions and the increases in PTH and CD1 mRNA expressions. The expression of both VDR and CASR are reduced in symptomatic PHPT in Asian Indians. In addition, CD1 expression was greatly increased and correlated with adenoma weight, implying a potential role for CD1 in adenoma growth and differential clinical expression of PHPT.

  20. PinX1 suppresses bladder urothelial carcinoma cell proliferation via the inhibition of telomerase activity and p16/cyclin D1 pathway.

    PubMed

    Liu, Jian-Ye; Qian, Dong; He, Li-Ru; Li, Yong-Hong; Liao, Yi-Ji; Mai, Shi-Juan; Tian, Xiao-Peng; Liu, Yan-Hui; Zhang, Jia-Xing; Kung, Hsiang-Fu; Zeng, Yi-Xin; Zhou, Fang-Jian; Xie, Dan

    2013-11-23

    PIN2/TRF1-interacting telomerase inhibitor1 (PinX1) was recently suggested as a putative tumor suppressor in several types of human cancer, based on its binding to and inhibition of telomerase. Moreover, loss of PinX1 has been detected in many human malignancies. However, the possible involvement of PinX1 and its clinical/prognostic significance in urothelial carcinoma of the bladder (UCB) are unclear. The PinX1 expression profile was examined by quantitative real-time polymerase chain reaction (qRT-PCR), western blotting, and immunohistochemistry (IHC) in UCB tissues and adjacent normal urothelial bladder epithelial tissues. PinX1 was overexpressed and silenced in UCB cell lines to determine its role in tumorigenesis, development of UCB, and the possible mechanism. PinX1 expression in UCB was significantly down-regulated at both mRNA and protein level as compared with that in normal urothelial bladder epithelial tissues. PinX1 levels were inversely correlated with tumor multiplicity, advanced N classification, high proliferation index (Ki-67), and poor survival (P < 0.05). Moreover, overexpression of PinX1 in UCB cells significantly inhibited cell proliferation in vitro and in vivo, whereas silencing PinX1 dramatically enhanced cell proliferation. Overexpression of PinX1 resulted in G1/S phase arrest and cell growth/proliferation inhibition, while silencing PinX1 led to acceleration of G1/S transition, and cell growth/proliferation promotion by inhibiting/enhancing telomerase activity and via the p16/cyclin D1 pathway. These findings suggest that down-regulation of PinX1 play an important role in the tumorigenesis and development of UCB and that the expression of PinX1 as detected by IHC is an independent molecular marker in patients with UCB.

  1. Cyclin D1 G870A polymorphism and breast cancer risk: a meta-analysis comprising 9,911 cases and 11,171 controls.

    PubMed

    Sergentanis, Theodoros N; Economopoulos, Konstantinos P

    2011-11-01

    Cyclin D1 represents a key molecule in the regulation of cell cycle. CCND1 G870A (rs603965) polymorphism has drawn considerable attention as the A allele may generate a variant splice product with possible oncogenic actions. A meta-analysis examining the association between CCND1 G870A polymorphism and breast cancer risk was performed. Separate analyses on Caucasian and Chinese populations were also implemented. Eligible articles were identified for the period up to July 2010. Pooled odds ratios (OR) were appropriately derived from fixed-effects or random-effects models. Sensitivity analysis excluding studies whose genotype frequencies in controls significantly deviated from Hardy-Weinberg Equilibrium (HWE) was performed. Nine case-control studies on Caucasians (7,304 cases and 8,149 controls) and four case-control studies on Chinese (2,607 cases and 3,022 controls) were eligible. At the overall analysis the A allele seemed to be associated with elevated breast cancer risk; the effect seemed to be confined to homozygous carriers (pooled OR = 1.091, 95% CI: 1.008-1.179, P = 0.030, fixed effects) as heterozygous carriers did not exhibit significantly elevated breast cancer risk. No statistically significant associations were demonstrated in Caucasians. On the other hand, Chinese AA carriers exhibited marginally elevated breast cancer risk (pooled OR = 1.144, 95% CI: 0.984-1.329, P = 0.080, fixed effects). Nevertheless, the controls in two out of the four Chinese studies deviated from HWE. In conclusion, this meta-analysis suggests that the A allele of the CCND1 G870A polymorphism may confer additional breast cancer risk when it comes to homozygosity and Chinese populations. The need for additional, methodologically sound studies on Chinese populations seems warranted.

  2. Expression of p53, p16, cyclin D1, epidermal growth factor receptor and Notch1 in patients with temporal bone squamous cell carcinoma.

    PubMed

    Morita, Shinya; Nakamaru, Yuji; Homma, Akihiro; Yasukawa, Shinichiro; Hatakeyama, Hiromitsu; Sakashita, Tomohiro; Kano, Satoshi; Fukuda, Atsushi; Fukuda, Satoshi

    2017-02-01

    The aim of this study was to investigate the expression of p53, p16, cyclin D1, epidermal growth factor receptor (EGFR) and Notch1 in temporal bone squamous cell carcinoma (TBSCC) tissue samples by immunohistochemistry (IHC), and to evaluate the association between these biomarkers and clinicopathological features. We performed a retrospective, single-institution review of 30 TBSCC patients treated with curative intent between April 2006 and March 2015. All tissue samples were obtained from pretreatment biopsy specimens or surgical specimens and using IHC staining. Ten patients were categorized as T1, seven as T2, five as T3 and eight as T4. Nine patients had clinically positive lymph node metastasis. The positive expression of p53 and EGFR was significantly associated with T classification (P = 0.042 and P = 0.0039). EGFR expression was significantly more frequent in patients with positive lymph node metastasis compared with patients without node involvement (P = 0.017). In the analysis of the association between protein expression by IHC staining and prognosis, the positive expression of EGFR and Notch1 was significantly correlated with poor survival outcomes in TBSCC (P = 0.015 and P = 0.025) CONCLUSION: Overexpression of p53 and EGFR may be valuable biomarkers for identifying individuals at high risk of developing tumors in TBSCC. Furthermore, the positive expression of EGFR was significantly associated with poor survival outcome. Anti-EGFR therapy has potential for use as the treatment modality of choice for advanced-stage TBSCC as well as other head and neck squamous cell carcinomas.

  3. Combination of atorvastatin with sulindac or naproxen profoundly inhibits colonic adenocarcinomas by suppressing the p65/β-catenin/cyclin D1 signaling pathway in rats

    PubMed Central

    Suh, Nanjoo; Reddy, Bandaru S.; DeCastro, Andrew; Paul, Shiby; Lee, Hong Jin; Smolarek, Amanda K.; So, Jae Young; Simi, Barbara; Wang, Chung Xiou; Janakiram, Naveena B.; Steele, Vernon; Rao, Chinthalapally V.

    2011-01-01

    Evidence supports the protective role of non-steroidal anti-inflammatory drugs (NSAIDs) and statins against colon cancer. Experiments were designed to evaluate the efficacies atorvastatin and NSAIDs administered individually and in combination against colon tumor formation. F344 rats were fed AIN-76A diet and colon tumors were induced with azoxymethane (AOM). One week after the second AOM-treatment groups of rats were fed diets containing atorvastatin (200 ppm), sulindac (100 ppm) or naproxen (150 ppm), or their combinations with low-dose atorvastatin (100 ppm) for 45 weeks. Administration of atorvastatin at 200 ppm significantly suppressed both adenocarcinoma incidence (52% reduction, p=0.005) and multiplicity (58% reduction, p=0.008). Most importantly, colon tumor multiplicities were profoundly decreased (80–85% reduction, p<0.0001) when given low-dose atorvastatin with either sulindac or naproxen. Also, a significant inhibition of colon tumor incidence was observed when given a low-dose atorvastatin with either sulindac (p=0.001) or naproxen (p =0.0005). Proliferation markers, proliferating cell nuclear antigen, cyclin D1 and β-catenin in tumors of rats exposed to sulindac, naproxen, atorvastatin, and/or combinations showed a significant suppression. Importantly, colon adenocarcinomas from atorvastatin and NSAIDs fed animals showed reduced key inflammatory markers, inducible nitric oxide synthase and cyclooxygenase-2, phospho-p65, as well as inflammatory cytokines, TNF-α, IL-1β, and IL-4. Overall, this is the first report on the combination treatment using low-dose atorvastatin with either low dose sulindac or naproxen, which greatly suppress the colon adenocarcinoma incidence and multiplicity. Our results suggest that low-dose atorvastatin with sulindac or naproxen might potentially be useful combinations for colon cancer prevention in humans. PMID:21764859

  4. Silencing of the Menkes copper-transporting ATPase (Atp7a) gene increases cyclin D1 protein expression and impairs proliferation of rat intestinal epithelial (IEC-6) cells.

    PubMed

    Gulec, Sukru; Collins, James F

    2014-10-01

    The Menkes copper-transporting ATPase (Atp7a) has dual roles in mammalian enterocytes: pumping copper into the trans-Golgi network (to support cuproenzyme synthesis) and across the basolateral membrane (to deliver dietary copper to the blood). Atp7a is strongly induced in the rodent duodenum during iron deprivation, suggesting that copper influences iron homeostasis. To investigate this possibility, Atp7a was silenced in rat intestinal epithelial (IEC-6) cells. Irrespective of its influence on iron homeostasis, an unexpected observation was made in the Atp7a knockdown (KD) cells: the cells grew slower (∼40% fewer cells at 96h) and were larger than negative-control shRNA-transfected cells. Lack of Atp7a activity thus perturbed cell cycle control. To elucidate a possible molecular mechanism, expression of two important cell cycle control proteins was assessed. Cyclin D1 (CD1) protein expression increased in Atp7a KD cells whereas proliferating-cell nuclear antigen (PCNA) expression was unaltered. Increased CD1 expression is consistent with impaired cell cycle progression. Expression of additional cell proliferation marker genes (p21 and Ki67) was also investigated; p21 expression increased, whereas Ki67 decreased, both consistent with diminished cell growth. Further experiments were designed to determine whether increased cellular copper content was the trigger for the altered growth phenotype of the Atp7a KD cells. Copper loading, however, did not influence the expression patterns of CD1, p21 or Ki67. Overall, these findings demonstrate that Atp7a is required for normal proliferation of IEC-6 cells. How Atp7a influences cell growth is unclear, but the underlying mechanism could relate to its roles in intracellular copper distribution or cuproenzyme synthesis. Copyright © 2014. Published by Elsevier GmbH.

  5. Contribution of cyclin D1 (CCND1) and E-cadherin (CDH1) alterations to colorectal cancer susceptibility: a case-control study.

    PubMed

    Govatati, Suresh; Singamsetty, Gopi Krishna; Nallabelli, Nayudu; Malempati, Sravanthi; Rao, Pasupuleti Sreenivasa; Madamchetty, Venkata Kranthi Kumar; Govatati, Sowdamani; Kanapuram, Rudramadevi; Narayana, Nagesh; Bhanoori, Manjula; Kassetty, Kondaiah; Nallanchakravarthula, Varadacharyulu

    2014-12-01

    Cyclin D1 (CCND1) and E-cadherin (CDH1) are two important genes of the β-catenin/LEF pathway that is involved in tumorigenesis of various cancers including colorectal cancer (CRC). However, studies of the association between genetic variants of these two genes and CRC have shown conflicting results. We conducted a genetic association study in South Indian population (cases, 103; controls, 107) to assess the association of CCND1 870G/A and CDH1 -160C/A single nucleotide polymorphisms (SNPs) with CRC risk. Genotyping of SNPs was performed by PCR sequencing analysis. Haplotype frequencies for multiple loci and the standardized disequilibrium coefficient (D') for pair-wise linkage disequilibrium (LD) were assessed by Haploview Software. In addition, to better understand the role of CCND1 and CDH1 in the pathophysiology of CRC, the expression pattern was evaluated in analogous tumor and adjacent normal tissues from 23 CRC patients by Western blot analysis. The frequencies of CCND1 870A/A (P = 0.045) genotype, CDH1 -160A allele (P = 0.042), and 870A/-160A haplotype (P = 0.002) were significantly higher in patients as compared with controls. Strong LD was observed between 870G/A and -160C/A SNPs in cases (D' = 0.76) as compared to controls (D' = 0.32). Furthermore, elevated CCND1 and diminished CDH1 expression was observed in tumor tissue as compared with analogous normal tissue of CRC patients. Interestingly, advanced-stage tumors showed wider expression alterations than in early-stage tumors. In conclusion, CCND1 870G/A and CDH1 -160C/A SNPs may modify the risk of CRC susceptibility in South Indian population. In addition, elevated CCND1 and diminished CDH1 expression appears to be useful prognostic markers for CRC.

  6. Combination of atorvastatin with sulindac or naproxen profoundly inhibits colonic adenocarcinomas by suppressing the p65/β-catenin/cyclin D1 signaling pathway in rats.

    PubMed

    Suh, Nanjoo; Reddy, Bandaru S; DeCastro, Andrew; Paul, Shiby; Lee, Hong Jin; Smolarek, Amanda K; So, Jae Young; Simi, Barbara; Wang, Chung Xiou; Janakiram, Naveena B; Steele, Vernon; Rao, Chinthalapally V

    2011-11-01

    Evidence supports the protective role of nonsteroidal anti-inflammatory drugs (NSAID) and statins against colon cancer. Experiments were designed to evaluate the efficacies atorvastatin and NSAIDs administered individually and in combination against colon tumor formation. F344 rats were fed AIN-76A diet, and colon tumors were induced with azoxymethane. One week after the second azoxymethane treatment, groups of rats were fed diets containing atorvastatin (200 ppm), sulindac (100 ppm), naproxen (150 ppm), or their combinations with low-dose atorvastatin (100 ppm) for 45 weeks. Administration of atorvastatin at 200 ppm significantly suppressed both adenocarcinoma incidence (52% reduction, P = 0.005) and multiplicity (58% reduction, P = 0.008). Most importantly, colon tumor multiplicities were profoundly decreased (80%-85% reduction, P < 0.0001) when given low-dose atorvastatin with either sulindac or naproxen. Also, a significant inhibition of colon tumor incidence was observed when given a low-dose atorvastatin with either sulindac (P = 0.001) or naproxen (P = 0.0005). Proliferation markers, proliferating cell nuclear antigen, cyclin D1, and β-catenin in tumors of rats exposed to sulindac, naproxen, atorvastatin, and/or combinations showed a significant suppression. Importantly, colon adenocarcinomas from atorvastatin and NSAIDs fed animals showed reduced key inflammatory markers, inducible nitric oxide synthase and COX-2, phospho-p65, as well as inflammatory cytokines, TNF-α, interleukin (IL)-1β, and IL-4. Overall, this is the first report on the combination treatment using low-dose atorvastatin with either low-dose sulindac or naproxen, which greatly suppress the colon adenocarcinoma incidence and multiplicity. Our results suggest that low-dose atorvastatin with sulindac or naproxen might potentially be useful combinations for colon cancer prevention in humans.

  7. Regulation of a Myb Transcription Factor by Cyclin-dependent Kinase 2 in Giardia lamblia*

    PubMed Central

    Cho, Chao-Cheng; Su, Li-Hsin; Huang, Yu-Chang; Pan, Yu-Jiao; Sun, Chin-Hung

    2012-01-01

    The protozoan Giardia lamblia parasitizes the human small intestine to cause diseases. It undergoes differentiation into infectious cysts by responding to intestinal stimulation. How the activated signal transduction pathways relate to encystation stimulation remain largely unknown. During encystation, genes encoding cyst wall proteins (CWPs) are coordinately up-regulated by a Myb2 transcription factor. Because cell differentiation is linked to cell cycle regulation, we tried to understand the role of cell cycle regulators, cyclin-dependent kinases (Cdks), in encystation. We found that the recombinant Myb2 was phosphorylated by Cdk-associated complexes and the levels of phosphorylation increased significantly during encystation. We have identified a putative cdk gene (cdk2) by searching the Giardia genome database. Cdk2 was found to localize in the cytoplasm with higher expression during encystation. Interestingly, overexpression of Cdk2 resulted in a significant increase of the levels of cwp gene expression and cyst formation. In addition, the Cdk2-associated complexes can phosphorylate Myb2 and the levels of phosphorylation increased significantly during encystation. Mutations of important catalytic residues of Cdk2 resulted in a significant decrease of kinase activity and ability of inducing cyst formation. Addition of a Cdk inhibitor, purvalanol A, significantly decreased the Cdk2 kinase activity and the levels of cwp gene expression and cyst formation. Our results suggest that the Cdk2 pathway may be involved in phosphorylation of Myb2, leading to activation of the Myb2 function and up-regulation of cwp genes during encystation. The results provide insights into the use of Cdk inhibitory drugs in disruption of Giardia differentiation into cysts. PMID:22167200

  8. Regulation of a Myb transcription factor by cyclin-dependent kinase 2 in Giardia lamblia.

    PubMed

    Cho, Chao-Cheng; Su, Li-Hsin; Huang, Yu-Chang; Pan, Yu-Jiao; Sun, Chin-Hung

    2012-02-03

    The protozoan Giardia lamblia parasitizes the human small intestine to cause diseases. It undergoes differentiation into infectious cysts by responding to intestinal stimulation. How the activated signal transduction pathways relate to encystation stimulation remain largely unknown. During encystation, genes encoding cyst wall proteins (CWPs) are coordinately up-regulated by a Myb2 transcription factor. Because cell differentiation is linked to cell cycle regulation, we tried to understand the role of cell cycle regulators, cyclin-dependent kinases (Cdks), in encystation. We found that the recombinant Myb2 was phosphorylated by Cdk-associated complexes and the levels of phosphorylation increased significantly during encystation. We have identified a putative cdk gene (cdk2) by searching the Giardia genome database. Cdk2 was found to localize in the cytoplasm with higher expression during encystation. Interestingly, overexpression of Cdk2 resulted in a significant increase of the levels of cwp gene expression and cyst formation. In addition, the Cdk2-associated complexes can phosphorylate Myb2 and the levels of phosphorylation increased significantly during encystation. Mutations of important catalytic residues of Cdk2 resulted in a significant decrease of kinase activity and ability of inducing cyst formation. Addition of a Cdk inhibitor, purvalanol A, significantly decreased the Cdk2 kinase activity and the levels of cwp gene expression and cyst formation. Our results suggest that the Cdk2 pathway may be involved in phosphorylation of Myb2, leading to activation of the Myb2 function and up-regulation of cwp genes during encystation. The results provide insights into the use of Cdk inhibitory drugs in disruption of Giardia differentiation into cysts.

  9. 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.

  10. MEK2 controls the activation of MKK3/MKK6-p38 axis involved in the MDA-MB-231 breast cancer cell survival: Correlation with cyclin D1 expression.

    PubMed

    Huth, Hugo W; Albarnaz, Jonas D; Torres, Alice A; Bonjardim, Claudio A; Ropert, Catherine

    2016-09-01

    The Ras-Raf-MEK-ERK1/2 signaling pathway regulates fundamental processes in malignant cells. However, the exact contributions of MEK1 and MEK2 to the development of cancer remain to be established. We studied the effects of MEK small-molecule inhibitors (PD98059 and U0126) and MEK1 and MEK2 knock-down on cell proliferation, apoptosis and MAPK activation. We showed a diminution of cell viability that was associated with a downregulation of cyclin D1 expression and an increase of apoptosis marker in MEK2 silenced cells; by contrast, a slight increase of cell survival was observed in the absence of MEK1 that correlated with an augment of cyclin D1 expression. These data indicate that MEK2 but not MEK1 is essential for MDA-MB-231 cell survival. Importantly, the role of MEK2 in cell survival appeared independent on ERK1/2 phosphorylation since its absence did not alter the level of activated ERK1/2. Indeed, we have reported an unrevealed link between MEK2 and MKK3/MKK6-p38 MAPK axis where MEK2 was essential for the phosphorylation of MKK3/MKK6 and p38 MAPK that directly impacted on cyclin D1 expression. Importantly, the MEK1 inhibitor PD98059, like MEK1 silencing, induced an augment of cyclin D1 expression that correlated with an increase of MDA-MB-231 cell proliferation suggesting that MEK1 may play a regulatory role in these cells. In sum, the crucial role of MEK2 in MDA-MB-231 cell viability and the unknown relationship between MEK2 and MKK3/MKK6-p38 axis here revealed may open new therapeutic strategies for aggressive breast cancer.

  11. GCIP, a novel human grap2 and cyclin D interacting protein, regulates E2F-mediated transcriptional activity.

    PubMed

    Xia, C; Bao, Z; Tabassam, F; Ma, W; Qiu, M; Hua, S; Liu, M

    2000-07-07

    Regulation of mammalian cell growth and proliferation is governed through receptor-mediated signaling networks that ultimately converge on the cell cycle machinery. Adaptor proteins play essential roles in the formation of intracellular signaling complexes, relaying extracellular signals from the plasma membrane to the nucleus of a cell. The leukocyte-specific adaptor protein Grap2 is a central linker protein in immune cell signaling and activation. Using Grap2 as bait protein, we identified a novel human protein, GCIP (Grap2 cyclin-D interacting protein). We found that GCIP bound to Grap2 in both yeast two-hybrid assays and in mammalian cells through binding to the COOH-terminal unique domain and SH3 domain (designated QC domain) of Grap2. GCIP also associated with cyclin D both in vitro and in vivo. The expression of GCIP was found in all human tissues examined with the highest level of expression in the heart, muscle, peripheral blood leukocytes, and brain. Furthermore, phosphorylation of retinoblastoma protein by cyclin D-dependent protein kinase was reduced and E2F1-mediated transcription activity was inhibited in cells transfected with GCIP. High level expression of GCIP in terminally differentiated tissues and the inhibition of E2F1 transcription activation suggest that GCIP could play an important role in controlling cell differentiation and proliferation.

  12. Small Molecule Inhibition of the Ubiquitin-specific Protease USP2 Accelerates cyclin D1 Degradation and Leads to Cell Cycle Arrest in Colorectal Cancer and Mantle Cell Lymphoma Models.

    PubMed

    Davis, Mindy I; Pragani, Rajan; Fox, Jennifer T; Shen, Min; Parmar, Kalindi; Gaudiano, Emily F; Liu, Li; Tanega, Cordelle; McGee, Lauren; Hall, Matthew D; McKnight, Crystal; Shinn, Paul; Nelson, Henrike; Chattopadhyay, Debasish; D'Andrea, Alan D; Auld, Douglas S; DeLucas, Larry J; Li, Zhuyin; Boxer, Matthew B; Simeonov, Anton

    2016-11-18

    Deubiquitinases are important components of the protein degradation regulatory network. We report the discovery of ML364, a small molecule inhibitor of the deubiquitinase USP2 and its use to interrogate the biology of USP2 and its putative substrate cyclin D1. ML364 has an IC50 of 1.1 μm in a biochemical assay using an internally quenched fluorescent di-ubiquitin substrate. Direct binding of ML364 to USP2 was demonstrated using microscale thermophoresis. ML364 induced an increase in cellular cyclin D1 degradation and caused cell cycle arrest as shown in Western blottings and flow cytometry assays utilizing both Mino and HCT116 cancer cell lines. ML364, and not the inactive analog 2, was antiproliferative in cancer cell lines. Consistent with the role of cyclin D1 in DNA damage response, ML364 also caused a decrease in homologous recombination-mediated DNA repair. These effects by a small molecule inhibitor support a key role for USP2 as a regulator of cell cycle, DNA repair, and tumor cell growth. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. Post-transcriptional regulation of dopamine D1 receptor expression in caudate-putamen of cocaine-sensitized mice.

    PubMed

    Tobón, Krishna E; Catuzzi, Jennifer E; Cote, Samantha R; Sonaike, Adenike; Kuzhikandathil, Eldo V

    2015-07-01

    The dopamine D1 receptor is centrally involved in mediating the effects of cocaine and is essential for cocaine-induced locomotor sensitization. Changes in D1 receptor expression have been reported in various models of cocaine addiction; however, the mechanisms that mediate these changes in D1 receptor expression are not well understood. Using preadolescent drd1a-EGFP mice and a binge cocaine treatment protocol we demonstrate that the D1 receptor is post-transcriptionally regulated in the caudate-putamen of cocaine-sensitized animal. While cocaine-sensitized mice express high levels of steady-state D1 receptor mRNA, the expression of D1 receptor protein is not elevated. We determined that the post-transcriptional regulation of D1 receptor mRNA is rapidly attenuated and D1 receptor protein levels increase within 30 min when the sensitized mice are challenged with cocaine. The rapid increase in D1 receptor protein levels requires de novo protein synthesis and correlates with the cocaine-induced hyperlocomotor activity in the cocaine-sensitized mice. The increase in D1 receptor protein levels in the caudate-putamen inversely correlated with the levels of microRNA 142-3p and 382, both of which regulate D1 receptor protein expression. The levels of these two microRNAs decreased significantly within 5 min of cocaine challenge in sensitized mice. The results provide novel insights into the previously unknown rapid kinetics of D1 receptor protein expression which occurs in a time scale that is comparable to the expression of immediate early genes. Furthermore, the results suggest a potential novel role for inherently labile microRNAs in regulating the rapid expression of D1 receptor protein in cocaine-sensitized animals.

  14. D1 dopamine receptor regulation of the levels of the cell-cycle-controlling proteins, cyclin D, P27 and Raf-1, in cerebral cortical precursor cells is mediated through cAMP-independent pathways.

    PubMed

    Zhang, Ling; Bai, Jie; Undie, Ashiwel S; Bergson, Clare; Lidow, Michael S

    2005-01-01

    Previously, we demonstrated that dopamine D1 receptor (D1R) agonists inhibit epidermal growth factor (EGF)-induced passage of mouse fetal cerebral cortical precursor cells from the G1 phase to the S phase of the cell cycle. Here, we report that this action of D1R agonists may involve regulation of cyclin D, and P27, which respectively promote and suppress the G1 to S transition. Furthermore, regulation of Raf-1, a component of the receptor tyrosine kinase mitogen-activated protein kinase pathway engaged in the mitogenic activity of EGF, may also be involved. Specifically, levels of cyclin D and Raf-1 decrease, whereas those of P27 first increase and then decrease in a dose-dependent fashion in response to the D1R agonist, SKF38393. This agonist also promotes Raf-1 phosphorylation on serine 338 residue, suggesting increased activation of this protein. Only the latter effect can be blocked by adenylyl cyclase (AC) and cAMP-dependent protein kinase A (PKA) inhibitors, and mimicked by agonists of the cAMP signaling pathway. Another D1R agonist, SKF83959, which stimulates phospholipase Cbeta (PLCbeta) but not AC, reduces levels of Raf-1 and cyclin D similar to SKF38393. However, we detected only down-regulation of P27 by this agonist. Additionally, the concentration-dependent patterns of both SKF38393- and SKF83959-induced alterations in the levels of P27 closely resemble the effects of these ligands on the levels of the D1R-PLCbeta-associated second-messenger cascades linker, calcyon. These findings suggest that D1R-induced suppression of the cell cycle progression in EGF-supported fetal cortical precursor cells represents a net effect of competing cell cycle promoting and inhibiting molecular changes, which involve cyclin D, P27 and Raf-1. The data also show that cAMP second messenger cascade is not engaged in the D1R-induced regulation of the levels of these three proteins. Such regulation probably involves PLCbeta-associated pathways.

  15. 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.

  16. 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

  17. A cross-talk between the androgen receptor and the epidermal growth factor receptor leads to p38MAPK-dependent activation of mTOR and cyclinD1 expression in prostate and lung cancer cells.

    PubMed

    Recchia, Anna Grazia; Musti, Anna Maria; Lanzino, Marilena; Panno, Maria Luisa; Turano, Ermanna; Zumpano, Rachele; Belfiore, Antonino; Andò, Sebastiano; Maggiolini, Marcello

    2009-03-01

    In androgen sensitive LNCaP prostate cancer cells, the proliferation induced by the epidermal growth factor (EGF) involves a cross-talk between the EGF receptor (EGFR) and the androgen receptor (AR). In lung cancer the role of the EGF-EGFR transduction pathway has been documented, whereas androgen activity has received less attention. Here we demonstrate that in LNCaP and A549 non-small cell lung cancer (NSCLC), AR and EGFR are required for either 5alpha-dihydrotestosterone (DHT) or EGF-stimulated cell growth. Only EGF activated ERK signaling and up-regulated early gene expression, while DHT triggered the expression of classical AR-responsive genes with the exception of the EGF-induced PSA transcript in A549 cells. DHT and EGF up-regulated cyclinD1 (CD1) at both mRNA and protein levels in A549 cells, while in LNCaP cells each mitogen increased only CD1 protein expression. In both cell contexts, CD1 up-regulation was prevented by selective inhibitors as well as by knock-down of either AR or EGFR and also inhibiting p38MAPK and the mammalian target of rapamycin (mTOR) pathways. Interestingly, p38MAPK and mTOR repression prevented the activation of the mTOR target ribosomal p70S6 kinase induced by DHT and EGF, indicating that p38MAPK acts as an upstream mTOR regulator. In addition, the proliferative effects promoted by both DHT and EGF in LNCaP and A549 cancer cells were no longer observed blocking either p38MAPK or mTOR activity. Hence, our data suggest that p38MAPK-dependent activation of the mTOR/CD1 pathway may represent a mechanism through which AR and EGFR cross-talk contributes to prostate and lung cancer progression.

  18. Cdk5-mediated inhibition of APC/C-Cdh1 switches on the cyclin D1-Cdk4-pRb pathway causing aberrant S-phase entry of postmitotic neurons.

    PubMed

    Veas-Pérez de Tudela, Miguel; Maestre, Carolina; Delgado-Esteban, María; Bolaños, Juan P; Almeida, Angeles

    2015-12-10

    The anaphase-promoting complex/cyclosome (APC/C) is an E3 ubiquitin ligase that regulates cell cycle progression in proliferating cells. To enter the S-phase, APC/C must be inactivated by phosphorylation of its cofactor, Cdh1. In post-mitotic cells such as neurons APC/C-Cdh1 complex is highly active and responsible for the continuous degradation of mitotic cyclins. However, the specific molecular pathway that determines neuronal cell cycle blockade in post-mitotic neurons is unknown. Here, we show that activation of glutamatergic receptors in rat cortical primary neurons endogenously triggers cyclin-dependent kinase-5 (Cdk5)-mediated phosphorylation of Cdh1 leading to its cytoplasmic accumulation and disassembly from the APC3 core protein, causing APC/C inactivation. Conversely, pharmacological or genetic inhibition of Cdk5 promotes Cdh1 ubiquitination and proteasomal degradation. Furthermore, we show that Cdk5-mediated phosphorylation and inactivation of Cdh1 leads to p27 depletion, which switches on the cyclin D1-cyclin-dependent kinase-4 (Cdk4)-retinoblastoma protein (pRb) pathway to allow the S-phase entry of neurons. However, neurons do not proceed through the cell cycle and die by apoptosis. These results indicate that APC/C-Cdh1 actively suppresses an aberrant cell cycle entry and death of neurons, highlighting its critical function in neuroprotection.

  19. Expression and cellular localization of the transcription factor NeuroD1 in the developing and adult rat pineal gland.

    PubMed

    Castro, Analía E; Benitez, Sergio G; Farias Altamirano, Luz E; Savastano, Luis E; Patterson, Sean I; Muñoz, Estela M

    2015-05-01

    Circadian rhythms govern many aspects of mammalian physiology. The daily pattern of melatonin synthesis and secretion is one of the classic examples of circadian oscillations. It is mediated by a class of neuroendocrine cells known as pinealocytes which are not yet fully defined. An established method to evaluate functional and cytological characters is through the expression of lineage-specific transcriptional regulators. NeuroD1 is a basic helix-loop-helix transcription factor involved in the specification and maintenance of both endocrine and neuronal phenotypes. We have previously described developmental and adult regulation of NeuroD1 mRNA in the rodent pineal gland. However, the transcript levels were not influenced by the elimination of sympathetic input, suggesting that any rhythmicity of NeuroD1 might be found downstream of transcription. Here, we describe NeuroD1 protein expression and cellular localization in the rat pineal gland during development and the daily cycle. In embryonic and perinatal stages, protein expression follows the mRNA pattern and is predominantly nuclear. Thereafter, NeuroD1 is mostly found in pinealocyte nuclei in the early part of the night and in cytoplasm during the day, a rhythm maintained into adulthood. Additionally, nocturnal nuclear NeuroD1 levels are reduced after sympathetic disruption, an effect mimicked by the in vivo administration of α- and β-adrenoceptor blockers. NeuroD1 phosphorylation at two sites, Ser(274) and Ser(336) , associates with nuclear localization in pinealocytes. These data suggest that NeuroD1 influences pineal phenotype both during development and adulthood, in an autonomic and phosphorylation-dependent manner.

  20. p53 Dimers associate with a head-to-tail response element to repress cyclin B transcription.

    PubMed

    Lipski, Robert; Lippincott, Daniel J; Durden, Brittany C; Kaplan, Anne R; Keiser, Hilary E; Park, Jung-Ho; Levesque, Aime A

    2012-01-01

    DNA damage induced by the topoisomerase I inhibitor SN38 activates cell cycle checkpoints which promote cell cycle arrest. This arrest can be abrogated in p53-defective cells by the Chk1 inhibitor 7-hydroxystaurosporine (UCN-01). Previously, we compared p53 wild-type MCF10A cells with derivatives whose p53 function was inhibited by over-expression of the tetramerization domain (MCF10A/OD) or expression of shRNA against p53 (MCF10A/Δp53). Treatment of SN38-arrested MCF10A/OD cells with UCN-01 abrogated S, but not G2 arrest, while the MCF10A/Δp53 cells abrogated both S and G2 arrest. The MCF10A/OD cells had reduced levels of cyclin B, suggesting that tetramerization of p53 is not required for repression of cyclin B gene expression. In the present study, we analyzed p53 oligomerization status using glutaraldehyde cross-linking. Following SN38 treatment, MCF10A cells contained oligomeric forms of p53 with molecular weights approximating monomers, dimers, trimers, and tetramers. However, MCF10A/OD cells possessed only monomers and dimers suggesting that these complexes may be involved in repression of cyclin B. While genes transcriptionally activated by p53 contain a consensus sequence with elements repeated in a head-to-head orientation, the cyclin B promoter contains similar elements oriented head-to-tail. Chromatin immunoprecipitation (ChIP) assays revealed that p53 associates with this head-to-tail element in both MCF10A and MCF10A/OD. Electrophoretic mobility shift assays (EMSA) using a biotin-labeled probe containing the head-to-tail element showed a shift in mobility consistent with the molecular weight of tetramers and dimers in MCF10A nuclear extract, but only the dimer in MCF10A/OD nuclear extract. Taken together, these results suggest a novel mechanism whereby p53 dimers associate with the head-to-tail element to repress cyclin B transcription.

  1. PlexinD1 Is a Novel Transcriptional Target and Effector of Notch Signaling in Cancer Cells

    PubMed Central

    Rehman, Michael; Capparuccia, Lorena

    2016-01-01

    The secreted semaphorin Sema3E controls cell migration and invasiveness in cancer cells. Sema3E-receptor, PlexinD1, is frequently upregulated in melanoma, breast, colon, ovarian and prostate cancers; however, the mechanisms underlying PlexinD1 upregulation and the downstream events elicited in tumor cells are still unclear. Here we show that the canonical RBPjk-dependent Notch signaling cascade controls PlexinD1 expression in primary endothelial and cancer cells. Transcriptional activation was studied by quantitative PCR and promoter activity reporter assays. We found that Notch ligands and constitutively activated intracellular forms of Notch receptors upregulated PlexinD1 expression; conversely RNAi-based knock-down, or pharmacological inhibition of Notch signaling by gamma-secretase inhibitors, downregulated PlexinD1 levels. Notably, both Notch1 and Notch3 expression positively correlates with PlexinD1 levels in prostate cancer, as well as in other tumor types. In prostate cancer cells, Sema3E-PlexinD1 axis was previously reported to regulate migration; however, implicated mechanisms were not elucidated. Here we show that in these cells PlexinD1 activity induces the expression of the transcription factor Slug, downregulates E-cadherin levels and enhances cell migration. Moreover, our mechanistic data identify PlexinD1 as a pivotal mediator of this signaling axis downstream of Notch in prostate cancer cells. In fact, on one hand, PlexinD1 is required to mediate cell migration and E-cadherin regulation elicited by Notch. On the other hand, PlexinD1 upregulation is sufficient to induce prostate cancer cell migration and metastatic potential in mice, leading to functional rescue in the absence of Notch. In sum, our work identifies PlexinD1 as a novel transcriptional target induced by Notch signaling, and reveals its role promoting prostate cancer cell migration and downregulating E-cadherin levels in Slug-dependent manner. Collectively, these findings suggest that

  2. 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

  3. 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

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

    2016-07-25

    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.

  4. Microcystic Stromal Tumor: A Distinctive Ovarian Sex Cord-Stromal Neoplasm Characterized by FOXL2, SF-1, WT-1, Cyclin D1, and β-catenin Nuclear Expression and CTNNB1 Mutations.

    PubMed

    Irving, Julie A; Lee, Cheng-Han; Yip, Stephen; Oliva, Esther; McCluggage, W Glenn; Young, Robert H

    2015-10-01

    Since our first description of the microcystic stromal tumor (MST) of the ovary, a rare and distinctive neoplasm with a definitional, usually striking microcystic pattern and a CD10+/vimentin+/inhibin-/calretinin- immunophenotype, 3 examples with β-catenin nuclear localization, and CTNNB1 mutation have been reported. We undertook a detailed immunohistochemical study and molecular analysis of CTNNB1 and FOXL2 of 15 cases of MST to further characterize this neoplasm and establish its histogenesis. Diffuse nuclear staining for FOXL2, WT-1, cyclin D1, and β-catenin was present in all tumors tested, and 12/15 were positive for steroidogenic factor-1 (SF-1). Heterozygous missense point mutations in exon 3 of CTNNB1 were detected in 8 of 14 cases, resulting in amino acid changes at codons 32, 34, 35, and 37. There was no correlation between CTNNB1 exon 3 mutation status and tumor immunophenotype. All 14 cases tested showed wild-type FOXL2. Our study establishes that MST of the ovary exhibits a characteristic FOXL2/SF-1/WT-1/cyclin D1/nuclear β-catenin-positive immunohistochemical profile, which may be useful in diagnosis and in the exclusion of histologic mimics. The presence of diffuse nuclear FOXL2 and WT-1 immunostaining in all cases and SF-1 in most supports the classification of MST within the sex cord-stromal category. Aberrant nuclear β-catenin expression, detected in all MSTs, appears to be the result of stabilizing CTNNB1 mutations in 57% of cases, providing further evidence that dysregulation of the Wnt/B-catenin pathway is involved in the tumorigenesis of MST and may involve activation of β-catenin with upregulation of cyclin D1.

  5. Kaposi's Sarcoma-Associated Herpesvirus Viral Interferon Regulatory Factor 4 (vIRF4) Perturbs the G1-S Cell Cycle Progression via Deregulation of the cyclin D1 Gene.

    PubMed

    Lee, Hye-Ra; Mitra, Jaba; Lee, Stacy; Gao, Shou-Jiang; Oh, Tae-Kwang; Kim, Myung Hee; Ha, Taekjip; Jung, Jae U

    2015-10-21

    Kaposi's sarcoma-associated herpesvirus (KSHV) infection modulates the host cell cycle to create an environment optimal for its viral-DNA replication during the lytic life cycle. We report here that KSHV vIRF4 targets the β-catenin/CBP cofactor and blocks its occupancy on the cyclin D1 promoter, suppressing the G1-S cell cycle progression and enhancing KSHV replication. This shows that KSHV vIRF4 suppresses host G1-S transition, possibly providing an intracellular milieu favorable for its replication.

  6. Cell cycle–regulated phosphorylation of p220NPAT by cyclin E/Cdk2 in Cajal bodies promotes histone gene transcription

    PubMed Central

    Ma, Tianlin; Van Tine, Brian A.; Wei, Yue; Garrett, Michelle D.; Nelson, David; Adams, Peter D.; Wang, Jin; Qin, Jun; Chow, Louise T.; Harper, J. Wade

    2000-01-01

    Cyclin E/Cdk2 acts at the G1/S-phase transition to promote the E2F transcriptional program and the initiation of DNA synthesis. To explore further how cyclin E/Cdk2 controls S-phase events, we examined the subcellular localization of the cyclin E/Cdk2 interacting protein p220NPAT and its regulation by phosphorylation. p220 is localized to discrete nuclear foci. Diploid fibroblasts in Go and G1 contain two p220 foci, whereas S- and G2-phase cells contain primarily four p220 foci. Cells in metaphase and telophase have no detectable focus. p220 foci contain cyclin E and are coincident with Cajal bodies (CBs), subnuclear organelles that associate with histone gene clusters on chromosomes 1 and 6. Interestingly, p220 foci associate with chromosome 6 throughout the cell cycle and with chromosome 1 during S phase. Five cyclin E/Cdk2 phosphorylation sites in p220 were identified. Phospho-specific antibodies against two of these sites react with p220 within CBs in a cell cycle–specific manner. The timing of p220 phosphorylation correlates with the appearance of cyclin E in CBs at the G1/S boundary, and this phosphorylation is maintained until prophase. Expression of p220 activates transcription of the histone H2B promoter. Importantly, mutation of Cdk2 phosphorylation sites to alanine abrogates the ability of p220 to activate the histone H2B promoter. Collectively, these results strongly suggest that p220NPAT links cyclical cyclin E/Cdk2 kinase activity to replication-dependent histone gene transcription. PMID:10995387

  7. Paullinia cupana Mart. var. sorbilis, guarana, increases survival of Ehrlich ascites carcinoma (EAC) bearing mice by decreasing cyclin-D1 expression and inducing a G0/G1 cell cycle arrest in EAC cells.

    PubMed

    Fukumasu, Heidge; Latorre, Andreia Oliveira; Zaidan-Dagli, Maria Lucia

    2011-01-01

    The objective of this work is to report the antiproliferative effect of P. cupana treatment in Ehrlich Ascites Carcinoma (EAC)-bearing animals. Female mice were treated with three doses of powdered P. cupana (100, 1000 and 2000 mg/kg) for 7 days, injected with 10(5) EAC cells and treated up to day 21. In addition, a survival experiment was carried out with the same protocol. P. cupana decreased the ascites volume (p = 0.0120), cell number (p = 0.0004) and hemorrhage (p = 0.0054). This occurred through a G1-phase arrest (p < 0.01) induced by a decreased gene expression of Cyclin D1 in EAC cells. Furthermore, P. cupana significantly increased the survival of EAC-bearing animals (p = 0.0012). In conclusion, the P. cupana growth control effect in this model was correlated with a decreased expression of cyclin D1 and a G1 phase arrest. These results reinforce the cancer therapeutic potential of this Brazilian plant. Copyright © 2010 John Wiley & Sons, Ltd.

  8. Doxorubicin and cyclophosphamide treatment produces anxiety-like behavior and spatial cognition impairment in rats: Possible involvement of hippocampal neurogenesis via brain-derived neurotrophic factor and cyclin D1 regulation.

    PubMed

    Kitamura, Yoshihisa; Hattori, Sayo; Yoneda, Saori; Watanabe, Saori; Kanemoto, Erika; Sugimoto, Misaki; Kawai, Toshiki; Machida, Ayumi; Kanzaki, Hirotaka; Miyazaki, Ikuko; Asanuma, Masato; Sendo, Toshiaki

    2015-10-01

    Many patients who have received chemotherapy to treat cancer experience depressive- and anxiety-like symptoms or cognitive impairment. However, despite the evidence for this, the underlying mechanisms are still not understood. This study investigated behavioral and biochemical changes upon treatment with doxorubicin and cyclophosphamide, focusing on mental and cognitive systems, as well as neurogenesis in male rats. Doxorubicin (2 mg/kg), cyclophosphamide (50 mg/kg), and the combination of doxorubicin and cyclophosphamide were injected intraperitoneally once per week for 4 weeks. In particular, the co-administration of doxorubicin and cyclophosphamide produced anhedonia-like, anxiety-like, and spatial cognitive impairments in rats. It also reduced both the number of proliferating cells in the subgranular zone of the hippocampal dentate gyrus and their survival. Serum brain-derived neurotrophic factor (BDNF) levels were decreased along with chemotherapy-induced decreases in platelet levels. However, hippocampal BDNF levels and Bdnf mRNA levels were not decreased by this treatment. On the other hand, hippocampal cyclin D1 levels were significantly decreased by chemotherapy. These results suggest that the co-administration of doxorubicin and cyclophosphamide induces psychological and cognitive impairment, in addition to negatively affecting hippocampal neurogenesis, which may be related to hippocampal cyclin D1 levels, but not hippocampal BDNF levels.

  9. CDK1-Cyclin B1 Activates RNMT, Coordinating mRNA Cap Methylation with G1 Phase Transcription.

    PubMed

    Aregger, Michael; Kaskar, Aneesa; Varshney, Dhaval; Fernandez-Sanchez, Maria Elena; Inesta-Vaquera, Francisco A; Weidlich, Simone; Cowling, Victoria H

    2016-03-03

    The creation of translation-competent mRNA is dependent on RNA polymerase II transcripts being modified by addition of the 7-methylguanosine (m7G) cap. The factors that mediate splicing, nuclear export, and translation initiation are recruited to the transcript via the cap. The cap structure is formed by several activities and completed by RNMT (RNA guanine-7 methyltransferase), which catalyzes N7 methylation of the cap guanosine. We report that CDK1-cyclin B1 phosphorylates the RNMT regulatory domain on T77 during G2/M phase of the cell cycle. RNMT T77 phosphorylation activates the enzyme both directly and indirectly by inhibiting interaction with KPNA2, an RNMT inhibitor. RNMT T77 phosphorylation results in elevated m7G cap methyltransferase activity at the beginning of G1 phase, coordinating mRNA capping with the burst of transcription that occurs following nuclear envelope reformation. RNMT T77 phosphorylation is required for the production of cohort of proteins, and inhibiting T77 phosphorylation reduces the cell proliferation rate. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  10. CDK1-Cyclin B1 Activates RNMT, Coordinating mRNA Cap Methylation with G1 Phase Transcription

    PubMed Central

    Aregger, Michael; Kaskar, Aneesa; Varshney, Dhaval; Fernandez-Sanchez, Maria Elena; Inesta-Vaquera, Francisco A.; Weidlich, Simone; Cowling, Victoria H.

    2016-01-01

    Summary The creation of translation-competent mRNA is dependent on RNA polymerase II transcripts being modified by addition of the 7-methylguanosine (m7G) cap. The factors that mediate splicing, nuclear export, and translation initiation are recruited to the transcript via the cap. The cap structure is formed by several activities and completed by RNMT (RNA guanine-7 methyltransferase), which catalyzes N7 methylation of the cap guanosine. We report that CDK1-cyclin B1 phosphorylates the RNMT regulatory domain on T77 during G2/M phase of the cell cycle. RNMT T77 phosphorylation activates the enzyme both directly and indirectly by inhibiting interaction with KPNA2, an RNMT inhibitor. RNMT T77 phosphorylation results in elevated m7G cap methyltransferase activity at the beginning of G1 phase, coordinating mRNA capping with the burst of transcription that occurs following nuclear envelope reformation. RNMT T77 phosphorylation is required for the production of cohort of proteins, and inhibiting T77 phosphorylation reduces the cell proliferation rate. PMID:26942677

  11. The p75NTR-interacting protein SC1 inhibits cell cycle progression by transcriptional repression of cyclin E

    PubMed Central

    Chittka, Alexandra; Arevalo, Juan Carlos; Rodriguez-Guzman, Maria; Pérez, Pilar; Chao, Moses V.; Sendtner, Michael

    2004-01-01

    Schwann cell factor 1 (SC1), a p75 neurotrophin receptor–interacting protein, is a member of the positive regulatory/suppressor of variegation, enhancer of zeste, trithorax (PR/SET) domain-containing zinc finger protein family, and it has been shown to be regulated by serum and neurotrophins. SC1 shows a differential cytoplasmic and nuclear distribution, and its presence in the nucleus correlates strongly with the absence of bromodeoxyuridine (BrdU) in these nuclei. Here, we investigated potential transcriptional activities of SC1 and analyzed the function of its various domains. We show that SC1 acts as a transcriptional repressor when it is tethered to Gal4 DNA-binding domain. The repressive activity requires a trichostatin A–sensitive histone deacetylase (HDAC) activity, and SC1 is found in a complex with HDACs 1, 2, and 3. Transcriptional repression exerted by SC1 requires the presence of its zinc finger domains and the PR domain. Additionally, these two domains are involved in the efficient block of BrdU incorporation by SC1. The zinc finger domains are also necessary to direct SC1's nuclear localization. Lastly, SC1 represses the promoter of a promitotic gene, cyclin E, suggesting a mechanism for how growth arrest is regulated by SC1. PMID:15051733

  12. D-type cyclins and G1 progression during liver development in the rat

    SciTech Connect

    Boylan, Joan M. . E-mail: Joan_Boylan@brown.edu; Gruppuso, Philip A. . E-mail: Philip_Gruppuso@brown.edu

    2005-05-13

    Initiation and progression through G1 requires the activity of signaling complexes containing cyclins (D- or E-type) and cyclin-dependent kinases (CDK4/6 and CDK2, respectively). We set out to identify the G1-phase cyclins and CDKs that are operative during late gestation liver development in the rat. This is a period during which hepatocytes show a high rate of proliferation that is, at least in part, independent of the mitogenic signaling pathways that are functional in mature hepatocytes. RNase protection assay and Western immunoblotting indicated that cyclin D1 is expressed at similar levels in fetal and adult liver. When cyclin D1 was induced after partial hepatectomy, its predominant CDK-binding partner was CDK4. In contrast, cyclins D2 and D3 predominated in fetal liver and were complexed with both CDK4 and CDK6. Little CDK6 protein was expressed in quiescent or regenerating adult liver. Cyclins E1 and E2 were both transcriptionally up-regulated in fetal liver. Activity of complexes containing cyclins E1 and E2 was higher in fetal liver, as was content of the cell cycle regulator, Rb. In fetal liver, Rb was highly phosphorylated at both cyclin D- and cyclin E-dependent sites. In conclusion, liver development is associated with a switch from cyclin D2/D3-containing complexes to cyclin D1:CDK4 complexes. We speculate that the switch in D-type cyclins may be associated with the dependence on mitogenic signaling that develops as hepatocytes mature.

  13. Nicotine induces cell proliferation in association with cyclin D1 up-regulation and inhibits cell differentiation in association with p53 regulation in a murine pre-osteoblastic cell line

    SciTech Connect

    Sato, Tsuyoshi Abe, Takahiro; Nakamoto, Norimichi; Tomaru, Yasuhisa; Koshikiya, Noboru; Nojima, Junya; Kokabu, Shoichiro; Sakata, Yasuaki; Kobayashi, Akio; Yoda, Tetsuya

    2008-12-05

    Recent studies have suggested that nicotine critically affects bone metabolism. Many studies have examined the effects of nicotine on proliferation and differentiation, but the underlying molecular mechanisms remain unclear. We examined cell cycle regulators involved in the proliferation and differentiation of MC3T3-E1 cells. Nicotine induced cell proliferation in association with p53 down-regulation and cyclin D1 up-regulation. In differentiated cells, nicotine reduced alkaline phosphatase activity and mineralized nodule formation in dose-dependent manners. Furthermore, p53 expression was sustained in nicotine-treated cells during differentiation. These findings indicate that nicotine promotes the cell cycle and inhibits differentiation in association with p53 regulation in pre-osteoblastic cells.

  14. 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.

  15. Epidermal Growth Factor Induces Proliferation of Hair Follicle-Derived Mesenchymal Stem Cells Through Epidermal Growth Factor Receptor-Mediated Activation of ERK and AKT Signaling Pathways Associated with Upregulation of Cyclin D1 and Downregulation of p16.

    PubMed

    Bai, Tingting; Liu, Feilin; Zou, Fei; Zhao, Guifang; Jiang, Yixu; Liu, Li; Shi, Jiahong; Hao, Deshun; Zhang, Qi; Zheng, Tong; Zhang, Yingyao; Liu, Mingsheng; Li, Shilun; Qi, Liangchen; Liu, Jin Yu

    2017-01-15

    The maintenance of highly proliferative capacity and full differentiation potential is a necessary step in the initiation of stem cell-based regenerative medicine. Our recent study showed that epidermal growth factor (EGF) significantly enhanced hair follicle-derived mesenchymal stem cell (HF-MSC) proliferation while maintaining the multilineage differentiation potentials. However, the underlying mechanism remains unclear. Herein, we investigated the role of EGF in HF-MSC proliferation. HF-MSCs were isolated and cultured with or without EGF. Immunofluorescence staining, flow cytometry, cytochemistry, and western blotting were used to assess proliferation, cell signaling pathways related to the EGF receptor (EGFR), and cell cycle progression. HF-MSCs exhibited surface markers of mesenchymal stem cells and displayed trilineage differentiation potentials toward adipocytes, chondrocytes, and osteoblasts. EGF significantly increased HF-MSC proliferation as well as EGFR, ERK1/2, and AKT phosphorylation (p-EGFR, p-ERK1/2, and p-AKT) in a time- and dose-dependent manner, but not STAT3 phosphorylation. EGFR inhibitor (AG1478), PI3K-AKT inhibitor (LY294002), ERK inhibitor (U0126), and STAT3 inhibitor (STA-21) significantly blocked EGF-induced HF-MSC proliferation. Moreover, AG1478, LY294002, and U0126 significantly decreased p-EGFR, p-AKT, and p-ERK1/2 expression. EGF shifted HF-MSCs at the G1 phase to the S and G2 phase. Concomitantly, cyclinD1, phosphorylated Rb, and E2F1expression increased, while that of p16 decreased. In conclusion, EGF induces HF-MSC proliferation through the EGFR/ERK and AKT pathways, but not through STAT-3. The G1/S transition was stimulated by upregulation of cyclinD1 and inhibition of p16 expression.

  16. An EBV recombinant deleted for residues 130-159 in EBNA3C can deregulate p53/Mdm2 and Cyclin D1/CDK6 which results in apoptosis and reduced cell proliferation

    PubMed Central

    El-Naccache, Darine W.; Robertson, Erle S.

    2016-01-01

    Epstein-Barr virus (EBV), a gamma herpes virus is associated with B-cell malignancies. EBNA-3C is critical for in vitro primary B-cell transformation. Interestingly, the N terminal domain of EBNA3C which contains residues 130–159, interacts with various cellular proteins, such as p53, Mdm2, CyclinD1/Cdk6 complex, and E2F1. In the current reverse genetics study, we deleted the residues 130-159 aa within EBNA3C open reading frame (ORF) by BACmid recombinant engineering methodology. Our experiments demonstrated that deletion of the 130-159 aa showed a reduction in cell proliferation. Also, this recombinant virus showed with higher infectivity of human peripheral blood mononuclear cells (PBMCs) compared to wild type EBV. PBMCs- infected with recombinant EBV deleted for 130-159 residues have differential expression patterns for the p53/Mdm2, CyclinD1/Cdk6 and pRb/E2F1 pathways compared to wild type EBV-infected PBMCs. PBMCs infected with recombinant virus showed increased apoptotic cell death which further resulted in activation of polymerase 1 (PARP1), an important contributor to apoptotic signaling. Interestingly, cells infected with this recombinant virus showed a dramatic decrease in chromosomal instability, indicated by the presence of increased multinucleation and micronucleation. In addition infection with recombinant virus have increased cells in G0/G1 phase and decreased cells in S-G2M phase when compared to wild type infected cells. Thus, these differences in signaling activities due to 29 amino acid residues of EBNA3C is of particular significance in deregulation of cell proliferation in EBV-infected cells. PMID:26908453

  17. Changes and predictive and prognostic value of the mitotic index, Ki-67, cyclin D1, and cyclo-oxygenase-2 in 710 operable breast cancer patients treated with neoadjuvant chemotherapy.

    PubMed

    Penault-Llorca, Frédérique; Abrial, Catherine; Raoelfils, Inès; Chollet, Philippe; Cayre, Anne; Mouret-Reynier, Marie-Ange; Thivat, Emilie; Mishellany, Florence; Gimbergues, Pierre; Durando, Xavier

    2008-12-01

    The current study expands upon previous work using a database of 710 patients treated with neoadjuvant chemotherapy. First, we studied phenotypic characteristics of tumors before and after chemotherapy using the following factors: the mitotic index of the Scarff-Bloom-Richardson grade, Ki-67, cyclin D1, and cyclo-oxygenase-2. Second, the predictive value of these factors on response was assessed. Third, we measured the prognostic impact of these markers post-therapy in comparison with clinical and pathological responses according to the Chevallier and Sataloff classifications. Patients were treated using different neoadjuvant chemotherapy combinations, mainly in successive prospective phase II trials. They received a median number of six cycles (range, 1-9). After neoadjuvant chemotherapy, patients underwent surgery and radiotherapy. In cases of important residual disease, some received additional courses of chemotherapy. In addition, menopausal patients with hormone receptor-positive tumors received tamoxifen for 5 years. According to our analysis, we found significant variations before and after neoadjuvant chemotherapy only for cyclin D1 and the mitotic index. Concerning the predictive value of biomarkers for response, Ki-67 and the mitotic index were predictive on univariate analysis, both for objective clinical and pathological complete responses. Because these two factors were correlated, no multivariate analyses were conducted. We then assessed the prognostic impact of the biopathological factors. When the factors were measured before chemotherapy, all were prognostic. When evaluated after chemotherapy, the mitotic index, objective clinical response, and pathological complete response were prognostic. Because these factors were correlated, no multivariate model was done. The main clinical fact is that there were significant correlations between clinical and pathological responses and variations in the biological factors studied.

  18. Regulation of small GTPase activity by G1 cyclins.

    PubMed

    Pedraza, Neus; Cemeli, Tània; Monserrat, Ma Ventura; Garí, Eloi; Ferrezuelo, Francisco

    2017-01-27

    Together with a cyclin-dependent kinase (CDK) partner G1 cyclins control cell cycle entry by phosphorylating a number of nuclear targets and releasing a transcriptional program at the end of G1 phase. Yeast G1 cyclins also operate on cytoplasmic targets involved in the polarization of the cytoskeleton and vesicle trafficking. These processes are mainly controlled by the small GTPase Cdc42, and G1 cyclins regulate the activity of this and other small GTPases through the modulation of their regulators and effectors. This regulation is key for different developmental outcomes in unicellular organisms. In mammalian cells cytoplasmic G1 cyclin D1 has been shown to promote the activity of Rac1 and Ral GTPases and to block RhoA. Regulation of these small GTPases by G1 cyclins may constitute a mechanism to coordinate proliferation with cell migration and morphogenesis, important processes not only during normal development and organogenesis but also for tumor formation and metastasis. Here we briefly review the evidence supporting a role of G1 cyclins and CDKs as regulators of the activity of small GTPases, emphasizing their functional relevance both in budding yeast and in mammalian cells.

  19. Cyclin-dependent Kinase 8 Module Expression Profiling Reveals Requirement of Mediator Subunits 12 and 13 for Transcription of Serpent-dependent Innate Immunity Genes in Drosophila*

    PubMed Central

    Kuuluvainen, Emilia; Hakala, Heini; Havula, Essi; Sahal Estimé, Michelle; Rämet, Mika; Hietakangas, Ville; Mäkelä, Tomi P.

    2014-01-01

    The Cdk8 (cyclin-dependent kinase 8) module of Mediator integrates regulatory cues from transcription factors to RNA polymerase II. It consists of four subunits where Med12 and Med13 link Cdk8 and cyclin C (CycC) to core Mediator. Here we have investigated the contributions of the Cdk8 module subunits to transcriptional regulation using RNA interference in Drosophila cells. Genome-wide expression profiling demonstrated separation of Cdk8-CycC and Med12-Med13 profiles. However, transcriptional regulation by Cdk8-CycC was dependent on Med12-Med13. This observation also revealed that Cdk8-CycC and Med12-Med13 often have opposite transcriptional effects. Interestingly, Med12 and Med13 profiles overlapped significantly with that of the GATA factor Serpent. Accordingly, mutational analyses indicated that GATA sites are required for Med12-Med13 regulation of Serpent-dependent genes. Med12 and Med13 were also found to be required for Serpent-activated innate immunity genes in defense to bacterial infection. The results reveal a novel role for the Cdk8 module in Serpent-dependent transcription and innate immunity. PMID:24778181

  20. The Hematopoietic Transcription Factor AML1 (RUNX1) Is Negatively Regulated by the Cell Cycle Protein Cyclin D3

    PubMed Central

    Peterson, Luke F.; Boyapati, Anita; Ranganathan, Velvizhi; Iwama, Atsushi; Tenen, Daniel G.; Tsai, Schickwann; Zhang, Dong-Er

    2005-01-01

    The family of cyclin D proteins plays a crucial role in the early events of the mammalian cell cycle. Recent studies have revealed the involvement of AML1 transactivation activity in promoting cell cycle progression through the induction of cyclin D proteins. This information in combination with our previous observation that a region in AML1 between amino acids 213 and 289 is important for its function led us to investigate prospective proteins associating with this region. We identified cyclin D3 by a yeast two-hybrid screen and detected AML1 interaction with the cyclin D family by both in vitro pull-down and in vivo coimmunoprecipitation assays. Furthermore, we demonstrate that cyclin D3 negatively regulates the transactivation activity of AML1 in a dose-dependent manner by competing with CBFβ for AML1 association, leading to a decreased binding affinity of AML1 for its target DNA sequence. AML1 and its fusion protein AML1-ETO have been shown to shorten and prolong the mammalian cell cycle, respectively. In addition, AML1 promotes myeloid cell differentiation. Thus, our observations suggest that the direct association of cyclin D3 with AML1 functions as a putative feedback mechanism to regulate cell cycle progression and differentiation. PMID:16287839

  1. A mutant E2F-1 transcription factor that affects the phenotype of NIH3T3 fibroblasts inefficiency associates with cyclin A-cdk2.

    PubMed

    Jordan-Sciutto, K L; Hall, D J

    1998-01-01

    The amino-terminal domain of the E2F1 transcription factor is the site of association with cyclin A-cdk2, mapping to residues 87-94. A mutant of E2F1 lacking the first 87 amino acids (termed E2F1d87) has a number of potent effects on cellular phenotype when constitutively expressed in NIH3T3 fibroblasts. For example, in these fibroblasts the duration of S phase and the sensitivity to S phase chemotherapeutic agents are both increased. Since E2F1d87 only partially truncates the cyclin A-cdk2 binding domain, it was important to determine the level of cyclin A-cdk2 association with this mutant to correlate any reduction in association with the observed effects on the cell cycle. It was found that cyclin A-cdk2 binds E2F1d87 in an in vitro assay but that this binding is reduced approximately 8 fold compared with binding to full-length E2F1, whereas no detectable binding was seen to a mutant E2F1 that lacks the first 117 amino acids. Correspondingly, H1 kinase activity in E2F1d87 immunoprecipitates from E2F1d87-expressing cells was significantly reduced compared with that seen for full-length E2F1. From these data it appears that E2F1 with reduced cyclin A-cdk2 binding activity mediates the alteration in cell cycle parameters seen in these cells.

  2. Enantioselective effect of 12(S)-hydroxyeicosatetraenoic acid on 3T6 fibroblast growth through ERK 1/2 and p38 MAPK pathways and cyclin D1 activation.

    PubMed

    Nieves, Diana; Moreno, Juan J

    2008-09-01

    Hydroxyeicosatetraenoic acids (HETEs) have numerous physiological effects, including modulation of cell proliferation and differentiation. However, little is known about the selective effects of HETE enantiomers on cell proliferation and cell signalling pathways involved in the regulation of cell growth. Furthermore, information on epithelial and endothelial cells growth is controversial. Recently, we demonstrated that 5-, 12-, and 15-HETE are involved in the control of 3T6 fibroblast growth though serine/treonine Akt/PKB (Akt) pathway. Here we examined the participation of both enantiomers (S and R) of HETEs in the control of 3T6 fibroblast growth. Our results show that HETEs (5-, 12-, and 15-HETE) are enantioselective on protein and DNA synthesis and 3T6 fibroblast growth. Furthermore, we observed that 12(S)-HETE induces the enhancement of cAMP and intracellular calcium concentration, whereas 12(R)-HETE was uneffective. Our findings also demonstrated that 12(S)-HETE exerts these effects through enantiospecific interactions with a cellular element, probably a plasma membrane receptor coupling to a pertussis toxin-sensitive protein G. Moreover, these elements may be involved in the activation of mitogen-activated protein kinase pathways which induce the enhancement of cyclin D(1) levels.

  3. Triphala Extract Suppresses Proliferation and Induces Apoptosis in Human Colon Cancer Stem Cells via Suppressing c-Myc/Cyclin D1 and Elevation of Bax/Bcl-2 Ratio

    PubMed Central

    Vadde, Ramakrishna; Radhakrishnan, Sridhar; Reddivari, Lavanya; Vanamala, Jairam K. P.

    2015-01-01

    Colon cancer is the second leading cause of cancer related deaths in the USA. Cancer stem cells (CSCs) have the ability to drive continued expansion of the population of malignant cells. Therefore, strategies that target CSCs could be effective against colon cancer and in reducing the risk of relapse and metastasis. In this study, we evaluated the antiproliferative and proapoptotic effects of triphala, a widely used formulation in Indian traditional medicine, on HCT116 colon cancer cells and human colon cancer stem cells (HCCSCs). The total phenolic content, antioxidant activity, and phytochemical composition (LC-MS-MS) of methanol extract of triphala (MET) were also measured. We observed that MET contains a variety of phenolics including naringin, quercetin, homoorientin, and isorhamnetin. MET suppressed proliferation independent of p53 status in HCT116 and in HCCSCs. MET also induced p53-independent apoptosis in HCCSCs as indicated by elevated levels of cleaved PARP. Western blotting data suggested that MET suppressed protein levels of c-Myc and cyclin D1, key proteins involved in proliferation, and induced apoptosis through elevation of Bax/Bcl-2 ratio. Furthermore, MET inhibited HCCSCs colony formation, a measure of CSCs self-renewal ability. Anticancer effects of triphala observed in our study warrant future studies to determine its efficacy in vivo. PMID:26167492

  4. Maple polyphenols, ginnalins A-C, induce S- and G2/M-cell cycle arrest in colon and breast cancer cells mediated by decreasing cyclins A and D1 levels.

    PubMed

    González-Sarrías, Antonio; Ma, Hang; Edmonds, Maxwell E; Seeram, Navindra P

    2013-01-15

    Polyphenols are bioactive compounds found in plant foods. Ginnalins A-C are polyphenols present in the sap and other parts of the sugar and red maple species which are used to produce maple syrup. Here we evaluated the antiproliferative effects of ginnalins A-C on colon (HCT-116) and breast (MCF-7) tumourigenic and non-tumourigenic colon (CCD-18Co) cells and investigated whether these effects were mediated through cell cycle arrest and/or apoptosis. Ginnalins A-C were twofold more effective against the tumourigenic than non-tumourigenic cells. Among the polyphenols, ginnalin A (84%, HCT-116; 49%, MCF-7) was more effective than ginnalins B and C (50%, HCT-116; 30%, MCF-7) at 50 μM concentrations. Ginnalin A did not induce apoptosis of the cancer cells but arrested cell cycle (in the S- and G(2)/M-phases) and decreased cyclins A and D1 protein levels. These results suggest that maple polyphenols may have potential cancer chemopreventive effects mediated through cell cycle arrest. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Enhanced expression of cyclins and cyclin-dependent kinases in aniline-induced cell proliferation in rat spleen

    PubMed Central

    Wang, Jianling; Wang, Gangduo; Ma, Huaxian; Khan, M. Firoze

    2010-01-01

    Aniline exposure is associated with toxicity to the spleen leading to splenomegaly, hyperplasia, fibrosis and a variety of sarcomas of the spleen on chronic exposure. In earlier studies, we have shown that aniline exposure leads to iron overload, oxidative stress and activation of redox-sensitive transcription factors, which could regulate various genes leading to a tumorigenic response in the spleen. However, molecular mechanisms leading to aniline-induced cellular proliferation in the spleen remain largely unknown. This study was, therefore, undertaken on the regulation of G1 phase cell cycle proteins (cyclins), expression of cyclin-dependent kinases (CDKs), phosphorylation of retinoblastoma protein (pRB) and cell proliferation in the spleen, in an experimental condition preceding a tumorigenic response. Male SD rats were treated with aniline (0.5 mmol/kg/day via drinking water) for 30 days (controls received drinking water only), and splenocyte proliferation, protein expression of G1 phase cyclins, CDKs and pRB were measured. Aniline treatment resulted in significant increases in splenocyte proliferation, based on cell counts, cell proliferation markers including proliferating cell nuclear antigen (PCNA), nuclear Ki67 protein (Ki67) and minichromosome maintenance (MCM), MTT assay and flow cytometric analysis. Western blot analysis of splenocyte proteins from aniline-treated rats showed significantly increased expression of cyclins D1, D2, D3 and cyclin E, as compared to the controls. Similarly, real-time PCR analysis showed significantly increased mRNA expression for cyclins D1, D2, D3 and E in the spleens of aniline-treated rats. The overexpression of these cyclins was associated with increases in the expression of CDK4, CDK6, CDK2 as well as phosphorylation of pRB protein. Our data suggest that increased expression of cyclins, CDKs and phosphorylation of pRB protein could be critical in cell proliferation, and may contribute to aniline-induced tumorigenic

  6. Transcription factor FBI-1 acts as a dual regulator in adipogenesis by coordinated regulation of cyclin-A and E2F-4.

    PubMed

    Laudes, Matthias; Bilkovski, Roman; Oberhauser, Frank; Droste, Andrea; Gomolka, Matthias; Leeser, Uschi; Udelhoven, Michael; Krone, Wilhelm

    2008-05-01

    Generation of new adipocytes plays a major role in the development of obesity. We previously have shown that transcriptional repressor factor that binds to IST (FBI)-1 exerts a dual effect in the process of adipogenesis by inhibiting proliferation and promoting differentiation of preadipocytes. The aim of the present study was to identify FBI-1 regulated molecular effectors that could account for these effects. Overexpressing FBI-1 in preadipocytes resulted in reduced expression of the cell cycle regulator cyclin A, which may explain FBI-1 induced inhibition of proliferation. Interestingly, FBI-1 repressed cyclin A promoter activity through an indirect mechanisms that did not involve direct binding of FBI-1 to the promoter sequence, but rather FBI-1 inhibition of transcriptional activator Sp1 binding to a regulatory element at -452 to -443. We also show that FBI-1 promotes terminal preadipocyte differentiation through a mechanism involving decreased levels of expression of the PPARgamma inhibitor E2F-4. FBI-1 significantly reduced E2F-4 promoter activity. Contrary to cyclin A, we found FBI-1-induced repression of E2F-4 is mediated by a direct mechanism via a FBI-1 regulatory element at -11 to -5. As function of transcriptional repressors normally depends on the presence of regulatory co-factors we also performed expression profiling of potential FBI-1 co-repressors throughout adipogenesis. In these experiments Sin3A and histon deacetylase (HDAC)-1 showed a similar expression pattern compared to FBI-1. Strikingly, co-immunoprecipitation studies revealed that FBI-1 binds Sin3A and HDAC-1 to form a repressor complex. Furthermore, by mutational analysis the amino terminal Poxvirus (POZ) domain of FBI-1 was found to be important for Sin3A and HDAC-1 binding. Taken together, FBI-1 is the first transcriptional repressor shown to act as a dual regulator in adipogenesis exerting repressor activities on target genes by both, direct and indirect mechanisms.

  7. DNA footprint analysis of the transcriptional activator proteins NodD1 and NodD3 on inducible nod gene promoters.

    PubMed Central

    Fisher, R F; Long, S R

    1989-01-01

    The Rhizobium meliloti nodD1 and nodD3 gene products (NodD1 and NodD3) are members of the lysR-nodD gene regulator family. They are functionally distinct in that NodD1 transcriptionally activates other nod genes in the presence of a flavonoid inducer such as luteolin, while NodD3 is capable of activating nod gene expression at high levels in the absence of inducer. NodD1 and NodD3 are DNA-binding proteins which interact with DNA sequences situated upstream of the transcription initiation sites of at least three sets of inducible nod genes. We report the footprinting of NodD1- and NodD3-DNA complexes with both DNase I and the 1,10-phenanthroline-copper ion reagent. NodD1 and NodD3 both interacted with the nodABC, nodFE, and nodH promoters and protected from cleavage an extensive piece of DNA, including the nod box, from approximately -20 to -75 from the transcription start site for each of the three promoters. The constitutively activating protein NodD3 displayed an additional hypersensitive cleavage site in its footprint compared with NodD1. Images PMID:2793828

  8. Regulation of the Candida albicans Hypha-Inducing Transcription Factor Ume6 by the CDK1 Cyclins Cln3 and Hgc1

    PubMed Central

    Mendelsohn, Sigal; Pinsky, Mariel; Weissman, Ziva

    2017-01-01

    ABSTRACT The ability to switch between proliferation as yeast cells and development into hyphae is a hallmark of Candida albicans. The switch to hyphal morphogenesis depends on external inducing conditions, but its efficiency is augmented in stationary-phase cells. Ume6, a transcription factor that is itself transcriptionally induced under hypha-promoting conditions, is both necessary and sufficient for hyphal morphogenesis. We found that Ume6 is regulated posttranslationally by the cell cycle kinase Cdc28/Cdk1, which reduces Ume6 activity via different mechanisms using different cyclins. Together with the cyclin Hgc1, Cdk1 promotes degradation of Ume6 via the SCFCDC4 ubiquitin ligase. Since HGC1 is a key transcriptional target of Ume6, this results in a negative-feedback loop between Hgc1 and Ume6. In addition, we found that Cln3, a G1 cyclin that is essential for cell cycle progression and yeast proliferation, suppresses hyphal morphogenesis and that Cln3 suppresses Ume6 activity both in the heterologous Saccharomyces cerevisiae system and in C. albicans itself. This activity of Cln3 may provide the basis for the antagonistic relationship between yeast proliferation and hyphal development in C. albicans. IMPORTANCE The yeast to hypha (mold) morphogenetic switch of Candida albicans plays a role in its virulence and constitutes a diagnostic trait for this organism, the most prevalent systemic fungal pathogen in industrialized countries. It has long been known that hyphae are most efficiently induced from stationary cultures. Here, a molecular basis for this observation is provided. The G1 cyclin Cln3, an essential promoter of yeast proliferation, was found to suppress hyphal induction. Suppression of hyphal induction is achieved by inhibition of the activity of the central activator of hyphal morphogenesis, the transcription factor Ume6. Thus, levels of Cln3 control the switch between proliferation of C. albicans as individual yeast cells and development into

  9. PI3K target based novel cyano derivative of betulinic acid induces its signalling inhibition by down-regulation of pGSK3β and cyclin D1 and potentially checks cancer cell proliferation.

    PubMed

    Majeed, Rabiya; Hussain, Aashiq; Sangwan, Payare L; Chinthakindi, Praveen K; Khan, Imran; Sharma, Parduman R; Koul, Surrinder; Saxena, Ajit K; Hamid, Abid

    2016-05-01

    In spite of the Betulinic acid (BA) being recognized as anticancerous source; its further use in clinical development is greatly hampered because of its poor pharmacokinetic properties. To circumvent these limitations, we synthesized a PI3K target based library of 18 triazole based derivatives and we identified a C-3 cyano analog of betulinic acid (CBA) with significant cell death effects with 5-7 fold higher potency than BA in various cancers. Importantly, no such report is available demonstrating the involvement of BA or its structural analogs in the modulation of PI3K pathway. Using, human leukemia HL-60 cells as a model, we for the first time report that CBA decreased expression of PI3K p110α, p85α, and pAKT in HL-60. Furthermore, we could find significant depletion of pGSK3β, cyclin D1 and increased expression of p21/cip, p27/Kip proteins. CBA induced G0/G1 cell cycle arrest, increased sub-G0 DNA fraction and annexin V binding of the cells besides imparting the typical surface features of cell death. Also, this target specific inhibition was associated with mitochondrial apoptosis as was reflected by expression studies of various proteins together with reactive oxygen species generation and decline in mitochondrial trans membrane potential. The apoptotic effectors i.e., caspase 8 and caspase 9 were found to get upregulated besides PI3K associated DNA repair enzyme i.e., PARP cleavage was observed. Thus, our results elucidated that CBA or other BA based small molecules inhibit PI3K/AKT pathway with induction of subsequent cancer cell death which may be useful therapeutic strategy against leukemias and possibly other cancers.

  10. Cyclin D-1, interleukin-6, HER-2/neu, transforming growth factor receptor-II and prediction of relapse in women with early stage, hormone receptor-positive breast cancer treated with tamoxifen.

    PubMed

    Muss, Hyman B; Bunn, Janice Yanushka; Crocker, Abigail; Plaut, Karen; Koh, James; Heintz, Nick; Rincon, Mercedes; Weaver, Donald L; Tam, Diane; Beatty, Barbara; Kaufman, Peter; Donovan, Michael; Verbel, David; Weiss, Linda

    2007-01-01

    We hypothesized that amplification or overexpression of HER-2 (c-erbB-2), the Ki-67 antigen (Mib1), cyclin D-1 (CD1), interleukin-6 (IL-6), or the transforming growth factor beta II receptor, (TGFbetaRII), would predict relapse in women with early stage, estrogen (ER) and/or progesterone receptor (PR) positive breast cancer treated with tamoxifen. Conditional logistic regression models and a new novel analytic method - support vector machines (SVM) were used to assess the effect of multiple variables on treatment outcome. All patients had stage I-IIIa breast cancer (AJCC version 5). We paired 63 patients who were disease-free on or after tamoxifen with 63 patients who had relapsed (total 126); both disease-free and relapsed patients were matched by duration of tamoxifen therapy and time to recurrence. These 126 patients also served as the training set for SVM analysis and 18 other patients used as a validation set for SVM. In a multivariate analysis, larger tumor size, increasing extent of lymph node involvement, and poorer tumor grade were significant predictors of relapse. When HER-2 or CD1 were added to the model both were borderline significant predictors of relapse. The SVM model, after including all of the clinical and marker variables in the 126 patients as a training set, correctly predicted relapse in 78% of the 18 patient validation samples. In this trial, HER-2 and CD1 proved of borderline significance as predictive factors for recurrence on tamoxifen. An SVM model that included all clinical and biologic variables correctly predicted relapse in >75% of patients.

  11. The CXCR4 inhibitor BL-8040 induces the apoptosis of AML blasts by down-regulating ERK BCL-2, MCL-1 and cyclin-D1 via altered miR-15a/16-1 expression.

    PubMed

    Abraham, M; Klein, S; Bulvik, B; Wald, H; Weiss, I D; Olam, D; Weiss, L; Beider, K; Eizenberg, O; Wald, O; Galun, E; Avigdor, A; Benjamini, O; Nagler, A; Pereg, Y; Tavor, S; Peled, A

    2017-03-10

    CXCR4 is a key player in the retention and survival of human acute myeloid leukemia (AML) blasts in the bone marrow (BM) microenvironment. We studied the effects of the CXCR4 antagonist BL-8040 on the survival of AML blasts and investigated the molecular mechanisms by which CXCR4 signaling inhibition leads to leukemic cell death. Treatment with BL-8040 induced the robust mobilization of AML blasts from the BM. In addition, AML cells exposed to BL-8040 underwent differentiation. Furthermore, BL-8040 induced the apoptosis of AML cells in vitro and in vivo. This apoptosis was mediated by the up-regulation of miR-15a/miR-16-1, resulting in down-regulation of the target genes BCL-2, MCL-1 and cyclin-D1. Overexpression of miR-15a/miR-16-1 directly induced leukemic cell death. BL-8040-induced apoptosis was also mediated by the inhibition of survival signals via the AKT/ERK pathways. Importantly, treatment with a BCL-2 inhibitor induced apoptosis and act together with BL-8040 to enhance cell death. BL-8040 also synergized with FLT3 inhibitors to induce AML cell death. Importantly, this combined treatment prolonged the survival of tumor-bearing mice and reduced minimal residual disease in vivo. Our results provide a rationale to test combination therapies employing BL-8040 and BCL2 or FLT3 inhibitors to achieve increased efficacy of these agents.Leukemia accepted article preview online, 10 March 2017. doi:10.1038/leu.2017.82.

  12. A Minimal Chimera of Human Cyclin T1 and Tat Binds TAR and Activates Human Immunodeficiency Virus Transcription in Murine Cells

    PubMed Central

    Fujinaga, Koh; Irwin, Dan; Taube, Ran; Zhang, Fan; Geyer, Matthias; Peterlin, B. Matija

    2002-01-01

    The transcriptional elongation of human immunodeficiency virus type 1 (HIV-1) is mediated by the virally encoded transactivator Tat and its cellular cofactor, positive transcription elongation factor b (P-TEFb). The human cyclin T1 (hCycT1) subunit of P-TEFb forms a stable complex with Tat and the transactivation response element (TAR) RNA located at the 5′ end of all viral transcripts. Previous studies have demonstrated that hCycT1 binds Tat in a Zn2+-dependent manner via the cysteine at position 261, which is a tyrosine in murine cyclin T1. In the present study, we mutated all other cysteines and histidines that could be involved in this Zn2+-dependent interaction. Because all of these mutant proteins except hCycT1(C261Y) activated viral transcription in murine cells, no other cysteine or histidine in hCycT1 is responsible for this interaction. Next, we fused the N-terminal 280 residues in hCycT1 with Tat. Not only the full-length chimera but also the mutant hCycT1 with an N-terminal deletion to position 249, which retained the Tat-TAR recognition motif, activated HIV-1 transcription in murine cells. This minimal hybrid mutant hCycT1-Tat protein bound TAR RNA as well as human and murine P-TEFb in vitro. We conclude that this minimal chimera not only reproduces the high-affinity binding among P-TEFb, Tat, and TAR but also will be invaluable for determining the three-dimensional structure of this RNA-protein complex. PMID:12438619

  13. The transcriptional network activated by Cln3 cyclin at the G1-to-S transition of the yeast cell cycle

    PubMed Central

    2010-01-01

    Background The G1-to-S transition of the cell cycle in the yeast Saccharomyces cerevisiae involves an extensive transcriptional program driven by transcription factors SBF (Swi4-Swi6) and MBF (Mbp1-Swi6). Activation of these factors ultimately depends on the G1 cyclin Cln3. Results To determine the transcriptional targets of Cln3 and their dependence on SBF or MBF, we first have used DNA microarrays to interrogate gene expression upon Cln3 overexpression in synchronized cultures of strains lacking components of SBF and/or MBF. Secondly, we have integrated this expression dataset together with other heterogeneous data sources into a single probabilistic model based on Bayesian statistics. Our analysis has produced more than 200 transcription factor-target assignments, validated by ChIP assays and by functional enrichment. Our predictions show higher internal coherence and predictive power than previous classifications. Our results support a model whereby SBF and MBF may be differentially activated by Cln3. Conclusions Integration of heterogeneous genome-wide datasets is key to building accurate transcriptional networks. By such integration, we provide here a reliable transcriptional network at the G1-to-S transition in the budding yeast cell cycle. Our results suggest that to improve the reliability of predictions we need to feed our models with more informative experimental data. PMID:20573214

  14. Enhanced expression of cyclins and cyclin-dependent kinases in aniline-induced cell proliferation in rat spleen

    SciTech Connect

    Wang Jianling; Wang Gangduo; Ma Huaxian; Khan, M. Firoze

    2011-01-15

    Aniline exposure is associated with toxicity to the spleen leading to splenomegaly, hyperplasia, fibrosis and a variety of sarcomas of the spleen on chronic exposure. In earlier studies, we have shown that aniline exposure leads to iron overload, oxidative stress and activation of redox-sensitive transcription factors, which could regulate various genes leading to a tumorigenic response in the spleen. However, molecular mechanisms leading to aniline-induced cellular proliferation in the spleen remain largely unknown. This study was, therefore, undertaken on the regulation of G1 phase cell cycle proteins (cyclins), expression of cyclin-dependent kinases (CDKs), phosphorylation of retinoblastoma protein (pRB) and cell proliferation in the spleen, in an experimental condition preceding a tumorigenic response. Male SD rats were treated with aniline (0.5 mmol/kg/day via drinking water) for 30 days (controls received drinking water only), and splenocyte proliferation, protein expression of G1 phase cyclins, CDKs and pRB were measured. Aniline treatment resulted in significant increases in splenocyte proliferation, based on cell counts, cell proliferation markers including proliferating cell nuclear antigen (PCNA), nuclear Ki67 protein (Ki67) and minichromosome maintenance (MCM), MTT assay and flow cytometric analysis. Western blot analysis of splenocyte proteins from aniline-treated rats showed significantly increased expression of cyclins D1, D2, D3 and E, as compared to the controls. Similarly, real-time PCR analysis showed significantly increased mRNA expression for cyclins D1, D2, D3 and E in the spleens of aniline-treated rats. The overexpression of these cyclins was associated with increases in the expression of CDK4, CDK6, CDK2 as well as phosphorylation of pRB protein. Our data suggest that increased expression of cyclins, CDKs and phosphorylation of pRB protein could be critical in cell proliferation, and may contribute to aniline-induced tumorigenic response in

  15. Enhanced expression of cyclins and cyclin-dependent kinases in aniline-induced cell proliferation in rat spleen.

    PubMed

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

    2011-01-15

    Aniline exposure is associated with toxicity to the spleen leading to splenomegaly, hyperplasia, fibrosis and a variety of sarcomas of the spleen on chronic exposure. In earlier studies, we have shown that aniline exposure leads to iron overload, oxidative stress and activation of redox-sensitive transcription factors, which could regulate various genes leading to a tumorigenic response in the spleen. However, molecular mechanisms leading to aniline-induced cellular proliferation in the spleen remain largely unknown. This study was, therefore, undertaken on the regulation of G1 phase cell cycle proteins (cyclins), expression of cyclin-dependent kinases (CDKs), phosphorylation of retinoblastoma protein (pRB) and cell proliferation in the spleen, in an experimental condition preceding a tumorigenic response. Male SD rats were treated with aniline (0.5 mmol/kg/day via drinking water) for 30 days (controls received drinking water only), and splenocyte proliferation, protein expression of G1 phase cyclins, CDKs and pRB were measured. Aniline treatment resulted in significant increases in splenocyte proliferation, based on cell counts, cell proliferation markers including proliferating cell nuclear antigen (PCNA), nuclear Ki67 protein (Ki67) and minichromosome maintenance (MCM), MTT assay and flow cytometric analysis. Western blot analysis of splenocyte proteins from aniline-treated rats showed significantly increased expression of cyclins D1, D2, D3 and E, as compared to the controls. Similarly, real-time PCR analysis showed significantly increased mRNA expression for cyclins D1, D2, D3 and E in the spleens of aniline-treated rats. The overexpression of these cyclins was associated with increases in the expression of CDK4, CDK6, CDK2 as well as phosphorylation of pRB protein. Our data suggest that increased expression of cyclins, CDKs and phosphorylation of pRB protein could be critical in cell proliferation, and may contribute to aniline-induced tumorigenic response in

  16. Nuclear receptor Rev-erb alpha (Nr1d1) functions in concert with Nr2e3 to regulate transcriptional networks in the retina.

    PubMed

    Mollema, Nissa J; Yuan, Yang; Jelcick, Austin S; Sachs, Andrew J; von Alpen, Désirée; Schorderet, Daniel; Escher, Pascal; Haider, Neena B

    2011-03-08

    The majority of diseases in the retina are caused by genetic mutations affecting the development and function of photoreceptor cells. The transcriptional networks directing these processes are regulated by genes such as nuclear hormone receptors. The nuclear hormone receptor gene Rev-erb alpha/Nr1d1 has been widely studied for its role in the circadian cycle and cell metabolism, however its role in the retina is unknown. In order to understand the role of Rev-erb alpha/Nr1d1 in the retina, we evaluated the effects of loss of Nr1d1 to the developing retina and its co-regulation with the photoreceptor-specific nuclear receptor gene Nr2e3 in the developing and mature retina. Knock-down of Nr1d1 expression in the developing retina results in pan-retinal spotting and reduced retinal function by electroretinogram. Our studies show that NR1D1 protein is co-expressed with NR2E3 in the outer neuroblastic layer of the developing mouse retina. In the adult retina, NR1D1 is expressed in the ganglion cell layer and is co-expressed with NR2E3 in the outer nuclear layer, within rods and cones. Several genes co-targeted by NR2E3 and NR1D1 were identified that include: Nr2c1, Recoverin, Rgr, Rarres2, Pde8a, and Nupr1. We examined the cyclic expression of Nr1d1 and Nr2e3 over a twenty-four hour period and observed that both nuclear receptors cycle in a similar manner. Taken together, these studies reveal a novel role for Nr1d1, in conjunction with its cofactor Nr2e3, in regulating transcriptional networks critical for photoreceptor development and function.

  17. 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

  18. Interaction of Heat Shock Protein Cpn10 with the Cyclin E/Cdk2 Substrate Nuclear Protein Ataxia-Telangiectasia (NPAT) Is Involved in Regulating Histone Transcription.

    PubMed

    Ling Zheng, Li; Wang, Fei Ya; Cong, Xiao Xia; Shen, Yue; Rao, Xi Sheng; Huang, Dao Sheng; Fan, Wei; Yi, Peng; Wang, Xin Bao; Zheng, Lei; Zhou, Yi Ting; Luo, Yan

    2015-12-04

    Precise modulation of histone gene transcription is critical for cell cycle progression. As a direct substrate of Cyclin E/CDK2, nuclear protein ataxia-telangiectasia (NPAT) is a crucial factor in regulating histone transcription and cell cycle progression. Here we identified that Cpn10/HSPE, a 10-kDa heat shock protein, is a novel interacting partner of NPAT. A pool of Cpn10 is colocalized with NPAT foci during G1 and S phases in nuclei. Gain- and loss-of-function experiments unraveled an essential role of Cpn10 in histone transcription. A conserved DLFD motif within Cpn10 was critical for targeting NPAT and modulating histone transcription. More importantly, knockdown of Cpn10 disrupted the focus formation of both NPAT and FADD-like interleukin-1β-converting enzyme-associated huge protein without affecting Coilin-positive Cajal bodies. Finally, Cpn10 is important for S phase progression and cell proliferation. Taken together, our finding revealed a novel role of Cpn10 in the spatial regulation of NPAT signaling and disclosed a previously unappreciated link between the heat shock protein and histone transcription regulation.

  19. Inhibition of P-TEFb (CDK9/Cyclin T) kinase and RNA polymerase II transcription by the coordinated actions of HEXIM1 and 7SK snRNA.

    PubMed

    Yik, Jasper H N; Chen, Ruichuan; Nishimura, Rieko; Jennings, Jennifer L; Link, Andrew J; Zhou, Qiang

    2003-10-01

    The positive transcriptional elongation factor b (P-TEFb), consisting of CDK9 and cyclin T, stimulates transcription by phosphorylating RNA polymerase II. It becomes inactivated when associated with the abundant 7SK snRNA. Here, we show that the 7SK binding alone was not sufficient to inhibit P-TEFb. P-TEFb was inhibited by the HEXIM1 protein in a process that specifically required 7SK for mediating the HEXIM1:P-TEFb interaction. This allowed HEXIM1 to inhibit transcription both in vivo and in vitro. P-TEFb dissociated from HEXIM1 and 7SK in cells undergoing stress response, increasing the level of active P-TEFb for stress-induced transcription. P-TEFb was the predominant HEXIM1-associated protein factor, and thus likely to be the principal target of inhibition coordinated by HEXIM1 and 7SK. Since HEXIM1 expression is induced in cells treated with hexamethylene bisacetamide, a potent inducer of cell differentiation, targeting the general transcription factor P-TEFb by HEXIM1/7SK may contribute to the global control of cell growth and differentiation.

  20. Interaction of Heat Shock Protein Cpn10 with the Cyclin E/Cdk2 Substrate Nuclear Protein Ataxia-Telangiectasia (NPAT) Is Involved in Regulating Histone Transcription*

    PubMed Central

    Ling Zheng, Li; Wang, Fei Ya; Cong, Xiao Xia; Shen, Yue; Rao, Xi Sheng; Huang, Dao Sheng; Fan, Wei; Yi, Peng; Wang, Xin Bao; Zheng, Lei; Zhou, Yi Ting; Luo, Yan

    2015-01-01

    Precise modulation of histone gene transcription is critical for cell cycle progression. As a direct substrate of Cyclin E/CDK2, nuclear protein ataxia-telangiectasia (NPAT) is a crucial factor in regulating histone transcription and cell cycle progression. Here we identified that Cpn10/HSPE, a 10-kDa heat shock protein, is a novel interacting partner of NPAT. A pool of Cpn10 is colocalized with NPAT foci during G1 and S phases in nuclei. Gain- and loss-of-function experiments unraveled an essential role of Cpn10 in histone transcription. A conserved DLFD motif within Cpn10 was critical for targeting NPAT and modulating histone transcription. More importantly, knockdown of Cpn10 disrupted the focus formation of both NPAT and FADD-like interleukin-1β-converting enzyme-associated huge protein without affecting Coilin-positive Cajal bodies. Finally, Cpn10 is important for S phase progression and cell proliferation. Taken together, our finding revealed a novel role of Cpn10 in the spatial regulation of NPAT signaling and disclosed a previously unappreciated link between the heat shock protein and histone transcription regulation. PMID:26429916

  1. HR96 and BR-C modulate phenobarbital induced transcription of cytochrome P450 CYP6D1 in Drosophila S2 cells

    PubMed Central

    Lin, G. G.-H.; Kozaki, T.; Scott, J. G.

    2010-01-01

    Phenobarbital (PB) is a prototypical inducer for studies of xenobiotic responses in animals. In mammals, nuclear receptors CAR and PXR have been identified as key transcription factors regulating PB induced transcription of xenobiotic responsive genes. In insects, much less is known about transcription factors involved in regulating PB induced transcription, although CAR and PXR have a single ortholog, HR96 (hormone receptor-like in 96), in Drosophila melanogaster. Using dual luciferase reporter assays in Drosophila S2 cells, constructs containing variable lengths of the promoter of the PB inducible cytochrome P450 CYP6D1 were evaluated in the presence and absence of PB. The promoter region between −330 and −280 (relative to the position of transcription start site, +1) was found to be critical for PB induction. Putative binding sites for Drosophila BR-C (broad-complex) and DFD (deformed) were identified within this promoter region using TFsearch. RNAi treatment of S2 cells in conjunction with CYP6D1 promoter assays showed that suppression of Drosophila HR96 and BR-C transcription in S2 cells resulted in a significant decrease and increase, respectively, of PB induction. Effects of HR96 and BR-C in mediating PB induction were PB specific and dependent. This represents new functional evidence that Drosophila HR96 and BR-C can act as an activator and repressor, respectively, regulating PB induced transcription in insects. PMID:21029232

  2. Pyruvate Dehydrogenase Kinase 4 Deficiency Results in Expedited Cellular Proliferation through E2F1-Mediated Increase of Cyclins.

    PubMed

    Choiniere, Jonathan; Wu, Jianguo; Wang, Li

    2017-03-01

    Hepatocellular carcinoma (HCC) is a common form of cancer with prevalence worldwide. There are many factors that lead to the development and progression of HCC. This study aimed to identify potential new tumor suppressors, examine their function as cell cycle modulators, and investigate their impact on the cyclin family of proteins and cyclin-dependent kinases (CDKs). In this study, the pyruvate dehydrogenase kinase (PDK)4 gene was shown to have potential tumor suppressor characteristics. PDK4 expression was significantly downregulated in human HCC. Pdk4(-/-) mouse liver exhibited a consistent increase in cell cycle regulator proteins, including cyclin D1, cyclin E1, cyclin A2, some associated CDKs, and transcription factor E2F1. PDK4-knockdown HCC cells also progressed faster through the cell cycle, which concurrently expressed high levels of cyclins and E2F1 as seen in the Pdk4(-/-) mice. Interestingly, the induced cyclin E1 and cyclin A2 caused by Pdk4 deficiency was repressed by arsenic treatment in mouse liver and in HCC cells. E2f1 deficiency in E2f1(-/-) mouse liver or knockdown E2F1 using small hairpin RNAs in HCC cells significantly decreased cyclin E1, cyclin A2, and E2F1 proteins. In contrast, inhibition of PDK4 activity in HCC cells increased cyclin E1, cyclin A2, and E2F1 proteins. These findings demonstrate that PDK4 is a critical regulator of hepatocyte proliferation via E2F1-mediated regulation of cyclins. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

  3. Curcumin improves the efficacy of cisplatin by targeting cancer stem-like cells through p21 and cyclin D1-mediated tumour cell inhibition in non-small cell lung cancer cell lines

    PubMed Central

    BAHARUDDIN, PUTERI; SATAR, NAZILAH; FAKIRUDDIN, KAMAL SHAIK; ZAKARIA, NORASHIKIN; LIM, MOON NIAN; YUSOFF, NARAZAH MOHD; ZAKARIA, ZUBAIDAH; YAHAYA, BADRUL HISHAM

    2016-01-01

    Natural compounds such as curcumin have the ability to enhance the therapeutic effectiveness of common chemotherapy agents through cancer stem-like cell (CSC) sensitisation. In the present study, we showed that curcumin enhanced the sensitivity of the double-positive (CD166+/EpCAM+) CSC subpopulation in non-small cell lung cancer (NSCLC) cell lines (A549 and H2170) to cisplatin-induced apoptosis and inhibition of metastasis. Our results revealed that initial exposure of NSCLC cell lines to curcumin (10–40 µM) markedly reduced the percentage of viability to an average of ~51 and ~54% compared to treatment with low dose cisplatin (3 µM) with only 94 and 86% in both the A549 and H2170 cells. Moreover, sensitisation of NSCLC cell lines to curcumin through combined treatment enhanced the single effect induced by low dose cisplatin on the apoptosis of the double-positive CSC subpopulation by 18 and 20% in the A549 and H2170 cells, respectively. Furthermore, we found that curcumin enhanced the inhibitory effects of cisplatin on the highly migratory CD166+/EpCAM+ subpopulation, marked by a reduction in cell migration to 9 and 21% in the A549 and H2170 cells, respectively, indicating that curcumin may increase the sensitivity of CSCs to cisplatin-induced migratory inhibition. We also observed that the mRNA expression of cyclin D1 was downregulated, while a substantial increased in p21 expression was noted, followed by Apaf1 and caspase-9 activation in the double-positive (CD166+/EpCAM+) CSC subpopulation of A549 cells, suggested that the combined treatments induced cell cycle arrest, therefore triggering CSC growth inhibition via the intrinsic apoptotic pathway. In conclusion, we provided novel evidence of the previously unknown therapeutic effects of curcumin, either alone or in combination with cisplatin on the inhibition of the CD166+/EpCAM+ subpopulation of NSCLC cell lines. This finding demonstrated the potential therapeutic approach of using curcumin that may

  4. Cyclin-dependent kinases

    PubMed Central

    2014-01-01

    Summary Cyclin-dependent kinases (CDKs) are protein kinases characterized by needing a separate subunit - a cyclin - that provides domains essential for enzymatic activity. CDKs play important roles in the control of cell division and modulate transcription in response to several extra- and intracellular cues. The evolutionary expansion of the CDK family in mammals led to the division of CDKs into three cell-cycle-related subfamilies (Cdk1, Cdk4 and Cdk5) and five transcriptional subfamilies (Cdk7, Cdk8, Cdk9, Cdk11 and Cdk20). Unlike the prototypical Cdc28 kinase of budding yeast, most of these CDKs bind one or a few cyclins, consistent with functional specialization during evolution. This review summarizes how, although CDKs are traditionally separated into cell-cycle or transcriptional CDKs, these activities are frequently combined in many family members. Not surprisingly, deregulation of this family of proteins is a hallmark of several diseases, including cancer, and drug-targeted inhibition of specific members has generated very encouraging results in clinical trials. PMID:25180339

  5. Cyclin-dependent kinases 7 and 9 specifically regulate neutrophil transcription and their inhibition drives apoptosis to promote resolution of inflammation

    PubMed Central

    Leitch, A E; Lucas, C D; Marwick, J A; Duffin, R; Haslett, C; Rossi, A G

    2012-01-01

    Terminally differentiated neutrophils are short-lived but the key effector cells of the innate immune response, and have a prominent role in the pathogenesis and propagation of many inflammatory diseases. Delayed apoptosis, which is responsible for their extended longevity, is critically dependent on a balance of intracellular survival versus pro-apoptotic proteins. Here, we elucidate the mechanism by which the cyclin-dependent kinase (CDK) inhibitor drugs such as R-roscovitine and DRB (5,6-dichloro-1-beta-𝒟-ribofuranosylbenzimidazole) mediate neutrophil apoptosis. We demonstrate (by a combination of microarray, confocal microscopy, apoptosis assays and western blotting) that the phosphorylation of RNA polymerase II by CDKs 7 and 9 is inhibited by R-roscovitine and that specific effects on neutrophil transcriptional capacity are responsible for neutrophil apoptosis. Finally, we show that specific CDK7 and 9 inhibition with DRB drives resolution of neutrophil-dominant inflammation. Thus, we highlight a novel mechanism that controls both primary human neutrophil transcription and apoptosis that could be targeted by selective CDK inhibitor drugs to resolve established inflammation. PMID:22743999

  6. Cyclin-dependent kinase 5 modulates the transcriptional activity of the mineralocorticoid receptor and regulates expression of brain-derived neurotrophic factor.

    PubMed

    Kino, Tomoshige; Jaffe, Howard; Amin, Niranjana D; Chakrabarti, Mayukh; Zheng, Ya-Li; Chrousos, George P; Pant, Harish C

    2010-05-01

    Glucocorticoids, major end effectors of the stress response, play an essential role in the homeostasis of the central nervous system (CNS) and contribute to memory consolidation and emotional control through their intracellular receptors, the glucocorticoid and mineralocorticoid receptors. Cyclin-dependent kinase 5 (CDK5), on the other hand, plays important roles in the morphogenesis and functions of the central nervous system, and its aberrant activation has been associated with development of neurodegenerative disorders. We previously reported that CDK5 phosphorylated the glucocorticoid receptor and modulated its transcriptional activity. Here we found that CDK5 also regulated mineralocorticoid receptor-induced transcriptional activity by phosphorylating multiple serine and threonine residues located in its N-terminal domain through physical interaction. Aldosterone and dexamethasone, respectively, increased and suppressed mRNA/protein expression of brain-derived neurotrophic factor (BDNF) in rat cortical neuronal cells, whereas the endogenous glucocorticoid corticosterone showed a biphasic effect. CDK5 enhanced the effect of aldosterone and dexamethasone on BDNF expression. Because this neurotrophic factor plays critical roles in neuronal viability, synaptic plasticity, consolidation of memory, and emotional changes, we suggest that aberrant activation of CDK5 might influence these functions through corticosteroid receptors/BDNF.

  7. The 3' untranslated region of human Cyclin-Dependent Kinase 5 Regulatory subunit 1 contains regulatory elements affecting transcript stability

    PubMed Central

    Moncini, Silvia; Bevilacqua, Annamaria; Venturin, Marco; Fallini, Claudia; Ratti, Antonia; Nicolin, Angelo; Riva, Paola

    2007-01-01

    Background CDK5R1 plays a central role in neuronal migration and differentiation during central nervous system development. CDK5R1 has been implicated in neurodegenerative disorders and proposed as a candidate gene for mental retardation. The remarkable size of CDK5R1 3'-untranslated region (3'-UTR) suggests a role in post-transcriptional regulation of CDK5R1 expression. Results The bioinformatic study shows a high conservation degree in mammals and predicts several AU-Rich Elements (AREs). The insertion of CDK5R1 3'-UTR into luciferase 3'-UTR causes a decreased luciferase activity in four transfected cell lines. We identified 3'-UTR subregions which tend to reduce the reporter gene expression, sometimes in a cell line-dependent manner. In most cases the quantitative analysis of luciferase mRNA suggests that CDK5R1 3'-UTR affects mRNA stability. A region, leading to a very strong mRNA destabilization, showed a significantly low half-life, indicating an accelerated mRNA degradation. The 3' end of the transcript, containing a class I ARE, specifically displays a stabilizing effect in neuroblastoma cell lines. We also observed the interaction of the stabilizing neuronal RNA-binding proteins ELAV with the CDK5R1 transcript in SH-SY5Y cells and identified three 3'-UTR sub-regions showing affinity for ELAV proteins. Conclusion Our findings evince the presence of both destabilizing and stabilizing regulatory elements in CDK5R1 3'-UTR and support the hypothesis that CDK5R1 gene expression is post-transcriptionally controlled in neurons by ELAV-mediated mechanisms. This is the first evidence of the involvement of 3'-UTR in the modulation of CDK5R1 expression. The fine tuning of CDK5R1 expression by 3'-UTR may have a role in central nervous system development and functioning, with potential implications in neurodegenerative and cognitive disorders. PMID:18053171

  8. Molecular Dissection of the 8 Phase Transcriptional Program Controlled by Cyclin E-P220 NPAT Signaling Pathway

    DTIC Science & Technology

    2005-04-01

    phase via the Cajal body -associated protein p220NPAT, and in addition, p220 can promote S-phase entry independently of histone transcriptional activation...p220 from Cajal bodies is associated with cell cycle arrest upon ionizing radiation- mediated DNA damage (Zhao 2004). Task 2. Dissociation of Cajal ... bodies in response to loss of p220. We have shown that p220-deficient cells display defects in localization of a Cajal body marker, coilin (Ye et al. 2003

  9. Selectivity and potency of cyclin-dependent kinase inhibitors.

    PubMed

    Sridhar, Jayalakshmi; Akula, Nagaraju; Pattabiraman, Nagarajan

    2006-03-24

    Members of the cyclin-dependent kinase (CDK) family play key roles in various cellular processes. There are 11 members of the CDK family known till now. CDKs are activated by forming noncovalent complexes with cyclins such as A-, B-, C-, D- (D1, D2, and D3), and E-type cyclins. Each isozyme of this family is responsible for particular aspects (cell signaling, transcription, etc) of the cell cycle, and some of the CDK isozymes are specific to certain kinds of tissues. Aberrant expression and overexpression of these kinases are evidenced in many disease conditions. Inhibition of isozymes of CDKs specifically can yield beneficiary treatment modalities with minimum side effects. More than 80 3-dimensional structures of CDK2, CDK5, and CDK6 complexed with inhibitors have been published. This review provides an understanding of the structural aspects of CDK isozymes and binding modes of various known CDK inhibitors so that these kinases can be better targeted for drug discovery and design. The amino acid residues that constitute the cyclin binding region, the substrate binding region, and the area around the adenosine triphosphate (ATP) binding site have been compared for CDK isozymes. Those amino acids at the ATP binding site that could be used to improve the potency and subtype specificity have been described.

  10. The Prognostic Value of the Immunohistochemical Expression of Phosphorylated RB and p16 Proteins in Association with Cyclin D1 and the p53 Pathway in a Large Cohort of Patients with Breast Cancer Treated with Taxane-based Adjuvant Chemotherapy.

    PubMed

    Gavressea, Theofani; Kalogeras, Konstantine T; Koliou, Georgia-Angeliki; Zagouri, Flora; Lazaridis, Georgios; Gogas, Helen; Tsigaridas, Kostas; Koutras, Angelos; Petraki, Kalliopi; Markopoulos, Christos; Pazarli, Elissavet; Aravantinos, Gerasimos; Papadimitriou, Christos; Papakostas, Pavlos; Koufopoulos, Nektarios; Karanikiotis, Charisios; Chrisafi, Sofia; Kalofonos, Haralambos P; Pectasides, Dimitrios; Fountzilas, George; Pavlakis, Kitty

    2017-06-01

    The retinoblastoma (RB) gene is a tumor-suppressor gene that plays a central role in regulating the cell cycle. Inactivation of this gene is involved in breast cancer. A total of 827 patients with breast cancer treated with taxane-based adjuvant chemotherapy were included in the study. Protein expression of RB, phosphorylated RB (pRB), p16, cyclin D1 and p53 was evaluated by immunohistochemistry. Neither of the retinoblastoma markers (RB and pRB) reached statistical significance in terms of their association with disease-free or overall survival. Nevertheless, when clustering analysis was performed, patients with tumors featuring low levels of p16, cyclin D1 and p53 with concomitantly high levels of pRB had reduced risk for relapse (Wald's p=0.015). The p53-mediated sensitivity of breast cancer cells to chemotherapeutic agents appears to be driven mostly by pRB. Using agents that enhance RB phosphorylation might possibly increase the chemosensitivity of breast cancer cells. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  11. Bryostatin 1 modulates beta-catenin subcellular localization and transcription activity through protein kinase D1 activation.

    PubMed

    Jaggi, Meena; Chauhan, Subhash C; Du, Cheng; Balaji, K C

    2008-09-01

    In recent years, the use of natural products for cancer prevention and treatment has received considerable attention. Bryostatin 1 is a natural macrocyclic lactone and a protein kinase D (PKD) modulator with potent antineoplastic properties that has been used to treat human cancers in clinical trials with limited success. Further understanding the mechanistic basis of Bryostatin 1 action may provide opportunities to improve clinical results of treatment with Bryostatin 1. We identified that PKD1, founding member of PKD family of serine/threonine kinases, modulates E-cadherin/beta-catenin activity, which plays an important role in cell integrity, polarity, growth, and morphogenesis. An aberrant expression and localization of E-cadherin/beta-catenin has been strongly associated with cancer progression and metastasis. In this study, we examined the effect of Bryostatin 1 treatment on PKD1 activation, beta-catenin translocation and transcription activity, and malignant phenotype of prostate cancer cells. Initial activation of PKD1 with Bryostatin 1 leads to colocalization of the cytoplasmic pool of beta-catenin with PKD1, trans-Golgi network markers, and proteins involved in vesicular trafficking. Activation of PKD1 by Bryostatin 1 decreases nuclear beta-catenin expression and beta-catenin/TCF transcription activity. Activation of PKD1 alters cellular aggregation and proliferation in prostate cancer cells associated with subcellular redistribution of E-cadherin and beta-catenin. For the first time, we have identified that Bryostatin 1 modulates beta-catenin signaling through PKD1, which identifies a novel mechanism to improve efficacy of Bryostatin 1 in clinical settings.

  12. Long non-coding RNA colon cancer-associated transcript 1 functions as a competing endogenous RNA to regulate cyclin-dependent kinase 1 expression by sponging miR-490-3p in hepatocellular carcinoma progression.

    PubMed

    Dou, Chunqing; Sun, Liyuan; Jin, Xin; Han, Mingming; Zhang, Bao; Li, Tao

    2017-04-01

    Hepatocellular carcinoma is an aggressive neoplasm and is one of the most common human cancers. Recently, long non-coding RNAs have been demonstrated to participate in pathogenesis of many diseases including the progression in several cancers. In this study, we found that the long non-coding RNA colon cancer-associated transcript 1 was upregulated in hepatocellular carcinoma tissues (p < 0.05), and high colon cancer-associated transcript 1 expression level was positively associated with tumor volume (p < 0.05) and American Joint Committee on Cancer stage (p < 0.05) in hepatocellular carcinoma patients. Luciferase reporter assays and RNA-pulldown assays showed that colon cancer-associated transcript 1 is a target of miR-490-3p. Real-time quantitative polymerase chain reaction and Western blot analysis indicated that colon cancer-associated transcript 1 regulated cyclin-dependent kinase 1 expression as a competing endogenous RNA by sponging miR-490-3p in hepatocellular carcinoma cells. Furthermore, colon cancer-associated transcript 1 silencing decreased hepatocellular carcinoma cells proliferation and invasion and overexpression promoted cell proliferation and invasion in vitro. These data demonstrated that the colon cancer-associated transcript 1/miR-490-3p/cyclin-dependent kinase 1 regulatory pathway promotes the progression of hepatocellular carcinoma. Inhibition of colon cancer-associated transcript 1 expression may be a novel therapeutic strategy for hepatocellular carcinoma.

  13. c-Myc represses FOXO3a-mediated transcription of the gene encoding the p27(Kip1) cyclin dependent kinase inhibitor.

    PubMed

    Chandramohan, Vidyalakshmi; Mineva, Nora D; Burke, Brian; Jeay, Sébastien; Wu, Min; Shen, Jian; Yang, William; Hann, Stephen R; Sonenshein, Gail E

    2008-08-15

    The p27(Kip1) (p27) cyclin-dependent kinase inhibitor and c-Myc oncoprotein play essential roles in control of cell cycle progression and apoptosis. Induction of p27 (CDKN1B) gene transcription by Forkhead box O proteins such as FOXO3a leads to growth arrest and apoptosis. Previously, we observed that B cell receptor (surface IgM) engagement of WEHI 231 immature B lymphoma cells with an anti-IgM antibody results in activation of FOXO3a, growth arrest and apoptosis. As ectopic c-Myc expression in these cells prevented anti-IgM induction of p27 and cell death, we hypothesized that c-Myc represses FOXO3a-mediated transcription. Here we show that c-Myc inhibits FOXO3a-mediated activation of the p27 promoter in multiple cell lines. The mechanism of this repression was explored using a combination of co-immunoprecipitation, oligonucleotide precipitation, and chromatin immunoprecipitation experiments. The studies demonstrate a functional association of FOXO3a and c-Myc on a proximal Forkhead binding element in the p27 promoter. This association involves the Myc box II domain of c-Myc and the N-terminal DNA-binding portion of FOXO3a. Analysis of publicly available microarray datasets showed an inverse pattern of c-MYC and p27 RNA expression in primary acute myeloid leukemia, prostate cancer and tongue squamous cell carcinoma samples. The inhibition of FOXO3a-mediated activation of the p27 gene by the high aberrant expression of c-Myc in many tumor cells likely contributes to their uncontrolled proliferation and invasive phenotype.

  14. Cell cycle stage-specific transcriptional activation of cyclins mediated by HAT2-dependent H4K10 acetylation of promoters in Leishmania donovani.

    PubMed

    Chandra, Udita; Yadav, Aarti; Kumar, Devanand; Saha, Swati

    2017-09-01

    Chromatin modifications affect several processes. In investigating the Leishmania donovani histone acetyltransferase HAT2, using in vitro biochemical assays and HAT2-heterozygous genomic knockout we found the constitutively nuclear HAT2 acetylated histone H4K10 in vitro and in vivo. HAT2 was essential. HAT2-depleted cells displayed growth and cell cycle defects, and poor survival in host cells. Real time PCR and DNA microarray analyses, as well as rescue experiments, revealed that downregulation of cyclins CYC4 and CYC9 were responsible for S phase and G2/M defects of HAT2-depleted cells respectively. Leishmania genes are arranged in unidirectional clusters, and clustered genes are coordinately transcribed as long polycistronic units, typically from divergent strand switch regions (dSSRs) which initiate transcription bidirectionally on opposite strands. In investigating the mechanism by which CYC4 and CYC9 expression levels are reduced in HAT2-depleted cells without other genes in their polycistronic transcription units being coordinately downregulated, we found using reporter assays that CYC4 and CYC9 have their own specific promoters. Chromatin immunoprecipitation assays with H4acetylK10 antibodies and real time PCR analyses of RNA suggested these gene-specific promoters were activated in cell cycle-dependent manner. Nuclear run-on analyses confirmed that CYC4 and CYC9 were transcriptionally activated from their own promoters at specific cell cycle stages. Thus, there are two tiers of gene regulation. Transcription of polycistronic units primarily initiates at dSSRs, and this most likely occurs constitutively. A subset of genes have their own promoters, at least some of which are activated in a cell-cycle dependent manner. This second tier of regulation is more sensitive to H4K10 acetylation levels, resulting in downregulation of expression in HAT2-depleted cells. This report presents the first data pointing to cell cycle-specific activation of promoters in

  15. Identification of multiple cyclin subunits of human P-TEFb

    PubMed Central

    Peng, Junmin; Zhu, Yuerong; Milton, Jeffrey T.; Price, David H.

    1998-01-01

    The transition from abortive into productive elongation is proposed to be controlled by a positive transcription elongation factor b (P-TEFb) through phosphorylation of the carboxy-terminal domain (CTD) of the largest subunit of RNA polymerase II. Drosophila P-TEFb was identified recently as a cyclin-dependent kinase (CDK9) paired with a cyclin subunit (cyclin T). We demonstrate here the cloning of multiple cyclin subunits of human P-TEFb (T1 and T2). Cyclin T2 has two forms (T2a and T2b) because of alternative splicing. Both cyclin T1 and T2 are ubiquitously expressed. Immunoprecipitation and immunodepletion experiments carried out on HeLa nuclear extract (HNE) indicated that cyclin T1 and T2 were associated with CDK9 in a mutually exclusive manner and that almost all CDK9 was associated with either cyclin T1 or T2. Recombinant CDK9/cyclin T1, CDK9/cyclin T2a, and CDK9/cyclin T2b produced in Sf9 cells possessed DRB-sensitive kinase activity and functioned in transcription elongation in vitro. Either cyclin T1 or T2 was required to activate CDK9, and the truncation of the carboxyl terminus of the cyclin reduced, but did not eliminate, P-TEFb activity. Cotransfection experiments indicated that all three CDK9/cyclin combinations dramatically activated the CMV promoter. PMID:9499409

  16. Growth arrest by the cyclin-dependent kinase inhibitor p27Kip1 is abrogated by c-Myc.

    PubMed Central

    Vlach, J; Hennecke, S; Alevizopoulos, K; Conti, D; Amati, B

    1996-01-01

    We show here that c-Myc antagonizes the cyclin-dependent kinase (CDK) inhibitor p27Kip1. p27 expressed from recombinant retroviruses in Rat1 cells associated with and inhibited cyclin E/CDK2 complexes, induced accumulation of the pRb and p130 proteins in their hypophosphorylated forms, and arrested cells in G1. Prior expression of c-Myc prevented inactivation of cyclin E/CDK2 as well as dephosphorylation of pRb and p130, and allowed continuous cell proliferation in the presence of p27. This effect did not require ubiquitin-mediated degradation of p27. Myc altered neither the susceptibility of cyclin E/CDK2 to inhibition by p27, nor the intrinsic CDK-inhibitory activity of p27, but induced sequestration of p27 in a form unable to bind cyclin E/CDK2. Neither Myc itself nor other G1-cyclin/CDK complexes were directly responsible for p27 sequestration. Retroviral expression of G1 cyclins (D1-3, E or A) or of the Cdc25A phosphatase did not overcome p27-induced arrest. Growth rescue by Myc required dimerization with Max, DNA binding and an intact transcriptional activation domain, as previously shown for cellular transformation. We propose that this activity is mediated by the product of an as yet unknown Myc-Max target gene(s) and represents an essential aspect of Myc's mitogenic and oncogenic functions. Images PMID:8978686

  17. Crystal Structure of Human Cyclin K, a Positive Regulator of Cyclin-dependent Kinase 9

    PubMed Central

    Baek, Kyuwon; Brown, Raymond S.; Birrane, Gabriel; Ladias, John A.A.

    2007-01-01

    Summary Cyclin K and the closely related cyclins T1, T2a, and T2b interact with cyclin-dependent kinase 9 (CDK9) forming multiple nuclear complexes, collectively referred to as positive transcription elongation factor b (P-TEFb). Through phosphorylation of the C-terminal domain of the RNA polymerase II largest subunit, distinct P-TEFb species regulate the transcriptional elongation of specific genes that play central roles in human physiology and disease development, including cardiac hypertrophy and human immunodeficiency virus-1 pathogenesis. We have determined the crystal structure of human cyclin K (residues 11-267) at 1.5 Å resolution, which represents the first atomic structure of a P-TEFb subunit. The cyclin K fold comprises two typical cyclin boxes with two short helices preceding the N-terminal box. A prominent feature of cyclin K is an additional helix (H4a) in the first cyclin box that obstructs the binding pocket for the cell cycle inhibitor p27Kip1. Modeling of CDK9 bound to cyclin K provides insights into the structural determinants underlying the formation and regulation of this complex. A homology model of human cyclin T1 generated using the cyclin K as a template reveals that the two proteins have similar structures, as expected from their high sequence identity. Nevertheless, their CDK9-interacting surfaces display significant structural differences, which could potentially be exploited for the design of cyclin-targeted inhibitors of the CDK9–cyclin K and CDK9–cyclin T1 complexes. PMID:17169370

  18. Helical fold prediction for the cyclin box.

    PubMed

    Bazan, J F

    1996-01-01

    The smooth progression of the eukaryotic cell cycle relies on the periodic activation of members of a family of cell cycle kinases by regulatory proteins called cyclins. Outside of the cell cycle, cyclin homologs play important roles in regulating the assembly of transcription complexes; distant structural relatives of the conserved cyclin core or "box" can also function as general transcription factors (like TFIIB) or survive embedded in the chain of the tumor suppressor, retinoblastoma protein. The present work attempts the prediction of the canonical secondary, supersecondary, and tertiary fold of the min