The overexpression of Rabl3 is associated with pathogenesis and clinicopathologic variables in hepatocellular carcinoma.

PubMed

Pan, Yuhang; Liu, Zhiyong; Feng, Zhiying; Hui, Dayang; Huang, Xiangqi; Tong, Dayue; Jin, Yi

2017-04-01

Overexpression of Rabl3 is associated with some malignancies. However, their relationship with hepatocellular carcinoma remains unclear. In this study, the expression of Rabl3 in hepatocellular carcinoma cell lines, and four pairs of matched hepatocellular carcinoma tissues and their adjacent normal hepatic tissues were detected by quantitative reverse transcription polymerase chain reaction and western blot. In addition, the protein expression of Rabl3 was examined in 162 cases of hepatocellular carcinoma by immunohistochemistry. Rabl3 in hepatocellular carcinoma cell lines was elevated at both messenger RNA and protein levels, and the Rabl3 protein was significantly upregulated by upto 3.3-fold in hepatocellular carcinoma compared with the paired normal hepatic tissues. Immunohistochemical analysis revealed that overexpressions of Rabl3 were 80.2% in hepatocellular carcinoma. Rabl3 is expressed at significantly higher rates in hepatocellular carcinoma compared with adjacent normal hepatic tissue (p < 0.01). Statistical analysis suggested the upregulation of Rabl3 was significantly associated with lymph node metastasis, tumor thrombus of the portal vein, and advanced clinical stage (p < 0.05). Furthermore, we found that overexpression of Rabl3 in hepatocellular carcinoma cells could significantly enhance cell proliferation and growth ability. Conversely, silencing Rabl3 by small hairpin RNA interference caused an inhibition of cell proliferation and growth. Our studies suggest that the Rabl3 is a valuable marker of hepatocellular carcinoma progression and that the overexpression of Rabl3 plays an important role in the development and pathogenesis of hepatocellular carcinoma.

Epigenetically Modified Bone Marrow Stromal Cells in Silk Scaffolds Promote Craniofacial Bone Repair and Wound Healing.

PubMed

Han, Qianqian; Yang, Pishan; Wu, Yuwei; Meng, Shu; Sui, Lei; Zhang, Lan; Yu, Liming; Tang, Yin; Jiang, Hua; Xuan, Dongying; Kaplan, David L; Kim, Sung Hoon; Tu, Qisheng; Chen, Jake

2015-08-01

Epigenetic regulation of gene expression is a central mechanism that governs cell stemness, determination, commitment, and differentiation. It has been recently found that PHF8, a major H4K20/H3K9 demethylase, plays a critical role in craniofacial and bone development. In this study, we hypothesize that PHF8 promotes osteoblastogenesis by epigenetically regulating the expression of a nuclear matrix protein, special AT-rich sequence-binding protein 2 (SATB2) that plays pivotal roles in skeletal patterning and osteoblast differentiation. Our results showed that expression levels of PHF8 and SATB2 in preosteoblasts and bone marrow stromal cells (BMSCs) increased simultaneously during osteogenic induction. Overexpressing PHF8 in these cells upregulated the expression of SATB2, Runx2, osterix, and bone matrix proteins. Conversely, knockdown of PHF8 reduced the expression of these genes. Furthermore, ChIP assays confirmed that PHF8 specifically bound to the transcription start site (TSS) of the SATB2 promoter, and the expression of H3K9me1 at the TSS region of SATB2 decreased in PHF8 overexpressed group. Implantation of the BMSCs overexpressing PHF8 with silk protein scaffolds promoted bone regeneration in critical-sized defects in mouse calvaria. Taken together, our results demonstrated that PHF8 epigenetically modulates SATB2 activity, triggering BMSCs osteogenic differentiation and facilitating bone formation and regeneration in biodegradable silk scaffolds.

miR-146b-5p promotes the neural conversion of pluripotent stem cells by targeting Smad4

PubMed Central

Zhang, Nianping; Lyu, Ying; Pan, Xuebing; Xu, Liping; Xuan, Aiguo; He, Xiaosong; Huang, Wandan; Long, Dahong

2017-01-01

Pluripotent stem cells (PSCs) are regarded as potential sources that provide specific neural cells for cell therapy in some nervous system diseases. However, the mechanisms underlying the neural differentiation of PSCs remain largely unknown. MicroRNAs (miRNAs or miRs) are a class of small non-protein-coding RNAs that act as critical regulatory molecules in many cellular processes. In this study, we found that miR-146b-5p expression was markedly increased following the neural induction of mouse embryonic stem cells (ESCs) or induced PSCs (iPSCs). In this study, to further identify the role of miR-146b-5p, we generated stable miR-146b-5p- overexpressing ESC and iPSC cell lines, and induced the differentiation of these cells by the adherent monolayer culture method. In the miR-146b-5p-overexpressing ESC- or iPSC- derived cultures, RT-qPCR analysis revealed that the mRNA expression levels of neuroectoderm markers, such as Sox1, Nestin and Pax6, were markedly increased, and flow cytometric analysis verified that the number of Nestin-positive cells was higher in the miR-146b-5p-overexpressing compared with the control cells. Mechanistically, the miR-146b-5p-overexpressing ESCs or iPSCs exhibited a significant reduction in Oct4 expression, which may be an explanation for these cells having a tendency to differentiate towards the neural lineage. Moreover, we confirmed that miR-146b-5p directly targeted Smad4 and negatively regulated the transforming growth factor (TGF)-β signaling pathway, which contributed to the neural commitment of PSCs. Collectively, our findings uncover the essential role of miR-146b-5p in the neural conversion of PSCs. PMID:28713933

DEK oncogene is overexpressed during melanoma progression.

PubMed

Riveiro-Falkenbach, Erica; Ruano, Yolanda; García-Martín, Rosa M; Lora, David; Cifdaloz, Metehan; Acquadro, Francesco; Ballestín, Claudio; Ortiz-Romero, Pablo L; Soengas, María S; Rodríguez-Peralto, José L

2017-03-01

DEK is an oncoprotein involved in a variety of cellular functions, such as DNA repair, replication, and transcriptional control. DEK is preferentially expressed in actively proliferating and malignant cells, including melanoma cell lines in which DEK was previously demonstrated to play a critical role in proliferation and chemoresistance. Still, the impact of this protein in melanoma progression remains unclear. Thus, we performed a comprehensive analysis of DEK expression in different melanocytic tumors. The immunostaining results of 303 tumors demonstrated negligible DEK expression in benign lesions. Conversely, malignant lesions, particularly in metastatic cases, were largely positive for DEK expression, which was partially associated with genomic amplification. Importantly, DEK overexpression was correlated with histological features of aggressiveness in primary tumors and poor prognosis in melanoma patients. In conclusion, our study provides new insight into the involvement of DEK in melanoma progression, as well as proof of concept for its potential application as a marker and therapeutic target of melanoma. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Ubiquitin over-expression phenotypes and ubiquitin gene molecular misreading during aging in Drosophila melanogaster

PubMed Central

Hoe, Nicholas; Huang, Chung M.; Landis, Gary; Verhage, Marian; Ford, Daniel; Yang, Junsheng; van Leeuwen, Fred W.; Tower, John

2011-01-01

Molecular Misreading (MM) is the inaccurate conversion of genomic information into aberrant proteins. For example, when RNA polymerase II transcribes a GAGAG motif it synthesizes at low frequency RNA with a two-base deletion. If the deletion occurs in a coding region, translation will result in production of misframed proteins. During mammalian aging, misframed versions of human amyloid precursor protein (hApp) and ubiquitin (hUbb) accumulate in the aggregates characteristic of neurodegenerative diseases, suggesting dysfunctional degradation or clearance. Here cDNA clones encoding wild-type hUbb and the frame-shifted version hUbb+1 were expressed in transgenic Drosophila using the doxycycline-regulated system. Misframed proteins were abundantly produced, both from the transgenes and from endogenous Drosophila ubiquitin-encoding genes, and their abundance increased during aging in whole-fly extracts. Over-expression of wild-type hUbb, but not hUbb+1, was toxic during fly development. In contrast, when over-expressed specifically in adult flies, hUbb+1 caused small decreases in life span, whereas hUbb was associated with small increases, preferentially in males. The data suggest that MM occurs in Drosophila and that the resultant misframed proteins accumulate with age. MM of the ubiquitin gene can produce alternative ubiquitin gene products with different and sometimes opposing phenotypic effects. PMID:21415465

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

PubMed

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

2018-05-01

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

Loss of Gnas imprinting differentially affects REM/NREM sleep and cognition in mice.

PubMed

Lassi, Glenda; Ball, Simon T; Maggi, Silvia; Colonna, Giovanni; Nieus, Thierry; Cero, Cheryl; Bartolomucci, Alessandro; Peters, Jo; Tucci, Valter

2012-01-01

It has been suggested that imprinted genes are important in the regulation of sleep. However, the fundamental question of whether genomic imprinting has a role in sleep has remained elusive up to now. In this work we show that REM and NREM sleep states are differentially modulated by the maternally expressed imprinted gene Gnas. In particular, in mice with loss of imprinting of Gnas, NREM and complex cognitive processes are enhanced while REM and REM-linked behaviors are inhibited. This is the first demonstration that a specific overexpression of an imprinted gene affects sleep states and related complex behavioral traits. Furthermore, in parallel to the Gnas overexpression, we have observed an overexpression of Ucp1 in interscapular brown adipose tissue (BAT) and a significant increase in thermoregulation that may account for the REM/NREM sleep phenotypes. We conclude that there must be significant evolutionary advantages in the monoallelic expression of Gnas for REM sleep and for the consolidation of REM-dependent memories. Conversely, biallelic expression of Gnas reinforces slow wave activity in NREM sleep, and this results in a reduction of uncertainty in temporal decision-making processes.

Recombinant protein expression in Pichia pastoris strains with an engineered methanol utilization pathway

PubMed Central

2012-01-01

Βackground The methylotrophic yeast Pichia pastoris has become an important host organism for recombinant protein production and is able to use methanol as a sole carbon source. The methanol utilization pathway describes all the catalytic reactions, which happen during methanol metabolism. Despite the importance of certain key enzymes in this pathway, so far very little is known about possible effects of overexpressing either of these key enzymes on the overall energetic behavior, the productivity and the substrate uptake rate in P. pastoris strains. Results A fast and easy-to-do approach based on batch cultivations with methanol pulses was used to characterize different P. pastoris strains. A strain with MutS phenotype was found to be superior over a strain with Mut+ phenotype in both the volumetric productivity and the efficiency in expressing recombinant horseradish peroxidase C1A. Consequently, either of the enzymes dihydroxyacetone synthase, transketolase or formaldehyde dehydrogenase, which play key roles in the methanol utilization pathway, was co-overexpressed in MutS strains harboring either of the reporter enzymes horseradish peroxidase or Candida antarctica lipase B. Although the co-overexpression of these enzymes did not change the stoichiometric yields of the recombinant MutS strains, significant changes in the specific growth rate, the specific substrate uptake rate and the specific productivity were observed. Co-overexpression of dihydroxyacetone synthase yielded a 2- to 3-fold more efficient conversion of the substrate methanol into product, but also resulted in a reduced volumetric productivity. Co-overexpression of formaldehyde dehydrogenase resulted in a 2-fold more efficient conversion of the substrate into product and at least similar volumetric productivities compared to strains without an engineered methanol utilization pathway, and thus turned out to be a valuable strategy to improve recombinant protein production. Conclusions Co-overexpressing enzymes of the methanol utilization pathway significantly affected the specific growth rate, the methanol uptake and the specific productivity of recombinant P. pastoris MutS strains. A recently developed methodology to determine strain specific parameters based on dynamic batch cultivations proved to be a valuable tool for fast strain characterization and thus early process development. PMID:22330134

Overexpression of SDF-1 activates the NF-κB pathway to induce epithelial to mesenchymal transition and cancer stem cell-like phenotypes of breast cancer cells.

PubMed

Kong, Lingxin; Guo, Sufen; Liu, Chunfeng; Zhao, Yiling; Feng, Chong; Liu, Yunshuang; Wang, Tao; Li, Caijuan

2016-03-01

The formation of EMT and EMT-induced CSC-like phenotype is crucial for the metastasis of tumor cells. The stromal cell-derived factor-1 (SDF-1) is upregulated in various human carcinomas, which is closely associated with proliferation, migration, invasion and prognosis of malignancies. However, limited attention has been directed towards the effect of SDF-1 on epithelial to mesenchymal transition (EMT) or cancer stem cell (CSC)-like phenotype formation in breast cancer cells and the related mechanism. In the present study, we screened MCF-7 cells with low SDF-1 expression level for the purpose of evaluating whether SDF-1 is involved in EMT and CSC-like phenotype formation in MCF-7 cells. The pEGFP-N1-SDF-1 plasmid was transfected into MCF-7 cells, and the stably overexpressed SDF-1 in MCF-7 cells was confirmed by real-time PCR and western blot analysis. Colony formation assay, MTT, wound healing assay and Transwell invasion assay demonstrated that overexpression of SDF-1 significantly boosted the proliferation, migration and invasion of MCF-7 cells compared with parental (P<0.05). Flow cytometry analysis revealed a notable increase of CD44+/CD24- subpopulation in SDF-1 overexpressing MCF-7 cells (P<0.001), accompanied by the apparently elevated ALDH activity and the upregulation of the stem cell markers OCT-4, Nanog, and SOX2 compared with parental (P<0.01). Besides, western blot analysis and immunofluorescence assay observed the significant decreased expression of E-cadherin and enhanced expression of slug, fibronectin and vimentin in SDF-1 overexpressed MCF-7 cells in comparison with parental (P<0.01). Further study found that overexpression of SDF-1 induced the activation of NF-κB pathway in MCF-7 cells. Conversely, suppressing or silencing p65 expression by antagonist or RNA interference could remarkably increase the expression of E-cadherin in SDF-1 overexpressed MCF-7 cells (P<0.001). Overall, the above results indicated that overexpression of SDF-1 enhanced EMT by activating the NF-κB pathway of MCF-7 cells and further induced the formation of CSC-like phenotypes, ultimately promoting the proliferation and metastasis of MCF-7 cells. Therefore, SDF-1 may further be assessed as a potential target for gene therapy of breast cancer.

Epigenetically Modified Bone Marrow Stromal Cells in Silk Scaffolds Promote Craniofacial Bone Repair and Wound Healing

PubMed Central

Han, Qianqian; Yang, Pishan; Wu, Yuwei; Meng, Shu; Sui, Lei; Zhang, Lan; Yu, Liming; Tang, Yin; Jiang, Hua; Xuan, Dongying; Kaplan, David L.; Kim, Sung Hoon

2015-01-01

Epigenetic regulation of gene expression is a central mechanism that governs cell stemness, determination, commitment, and differentiation. It has been recently found that PHF8, a major H4K20/H3K9 demethylase, plays a critical role in craniofacial and bone development. In this study, we hypothesize that PHF8 promotes osteoblastogenesis by epigenetically regulating the expression of a nuclear matrix protein, special AT-rich sequence-binding protein 2 (SATB2) that plays pivotal roles in skeletal patterning and osteoblast differentiation. Our results showed that expression levels of PHF8 and SATB2 in preosteoblasts and bone marrow stromal cells (BMSCs) increased simultaneously during osteogenic induction. Overexpressing PHF8 in these cells upregulated the expression of SATB2, Runx2, osterix, and bone matrix proteins. Conversely, knockdown of PHF8 reduced the expression of these genes. Furthermore, ChIP assays confirmed that PHF8 specifically bound to the transcription start site (TSS) of the SATB2 promoter, and the expression of H3K9me1 at the TSS region of SATB2 decreased in PHF8 overexpressed group. Implantation of the BMSCs overexpressing PHF8 with silk protein scaffolds promoted bone regeneration in critical-sized defects in mouse calvaria. Taken together, our results demonstrated that PHF8 epigenetically modulates SATB2 activity, triggering BMSCs osteogenic differentiation and facilitating bone formation and regeneration in biodegradable silk scaffolds. PMID:25923143

Overexpression of host plant urease in transgenic silkworms.

PubMed

Jiang, Liang; Huang, Chunlin; Sun, Qiang; Guo, Huizhen; Peng, Zhengwen; Dang, Yinghui; Liu, Weiqiang; Xing, Dongxu; Xu, Guowen; Zhao, Ping; Xia, Qingyou

2015-06-01

Bombyx mori and mulberry constitute a model of insect-host plant interactions. Urease hydrolyzes urea to ammonia and is important for the nitrogen metabolism of silkworms because ammonia is assimilated into silk protein. Silkworms do not synthesize urease and acquire it from mulberry leaves. We synthesized the artificial DNA sequence ureas using the codon bias of B. mori to encode the signal peptide and mulberry urease protein. A transgenic vector that overexpresses ure-as under control of the silkworm midgut-specific P2 promoter was constructed. Transgenic silkworms were created via embryo microinjection. RT-PCR results showed that urease was expressed during the larval stage and qPCR revealed the expression only in the midgut of transgenic lines. Urea concentration in the midgut and hemolymph of transgenic silkworms was significantly lower than in a nontransgenic line when silkworms were fed an artificial diet. Analysis of the daily body weight and food conversion efficiency of the fourth and fifth instar larvae and economic characteristics indicated no differences between transgenic silkworms and the nontransgenic line. These results suggested that overexpression of host plant urease promoted nitrogen metabolism in silkworms.

Overexpression of an endo-1,4-β-glucanase V gene (EGV) from Trichoderma reesei leads to the accumulation of cellulase activity in transgenic rice.

PubMed

Li, X Y; Liu, F; Hu, Y F; Xia, M; Cheng, B J; Zhu, S W; Ma, Q

2015-12-21

The ectopic expression of cellulase in biomass can reduce the cost of biofuel conversion. This trait modification technique is highly beneficial for biofuel production. In this study, we isolated an endo-1,4-beta-glucanase gene (EGV) from Trichoderma reesei and inserted this gene downstream of a fragment encoding the signal peptide Apo-SP in a modified pCAMBIA1301 vector to obtain an Apo-SP and AsRed fusion protein. Transient expression of this fusion protein in onion epidermal cells showed that the Apo-SP signal was localized to the plastids. EGV transgenic rice plants that did not carry screening marker genes were obtained through overexpression of the pDTB double T-DNA vector. Western blotting showed that EGV was expressed in the dry straw of T0 generation transgenic rice plants and in fresh leaves of the T1 generation. More importantly, our results also showed that the peptide product of EGV in the transgenic plants folded correctly and was capable of digesting the cellulase substrate CMC. Additionally, cellulase activity remained stable in the straw that had been dried at room temperature for three months. This study presents an important technical approach for the development of transgenic rice straw that has stable cellulase activity and can be used for biofuel conversion.

Yak IGF2 Promotes Fibroblast Proliferation Via Suppression of IGF1R and PI3KCG Expression

PubMed Central

Wang, Qi; Gong, Jishang; Du, Jiaxing; Zhang, Yong; Zhao, Xingxu

2018-01-01

Insulin-like growth factor 2 (IGF2) recapitulates many of the activities of insulin and promotes differentiation of myoblasts and osteoblasts, which likely contribute to genetic variations of growth potential. However, little is known about the functions and signaling properties of IGF2 variants in yaks. The over-expression vector and knockdown sequence of yak IGF2 were transfected into yak fibroblasts, and the effects were detected by a series of assays. IGF2 expression in yak muscle tissues was significantly lower than that of other tissues. In yak fibroblasts, the up-regulated expression of IGF2 inhibits expression of IGF1 and insulin-like growth factor 2 receptor (IGF2R) and significantly up-regulates expression of IGF1R. Inhibition of IGF2 expression caused the up-regulates expression of IGF1, IGF1R and IGF2R. Both over-expression and knockdown of IGF2 resulted in up-regulation of threonine protein kinase 1 (Akt1) expression and down-regulation of phosphatidylinositol 3-kinase, catalytic subunit gamma (PIK3CG). Cell cycle and cell proliferation assays revealed that over-expression of IGF2 enhanced the DNA synthesis phase and promoted yak fibroblasts proliferation. Conversely, knockdown of IGF2 decreased DNA synthesis and inhibited proliferation. These results suggested that IGF2 was negatively correlated with IGF1R and PIK3CG and demonstrated an association with the IGFs-PI3K-Akt (IGFs-phosphatidylinositol 3-kinase- threonine protein kinase) pathway in cell proliferation and provided evidence supporting the functional role of IGF2 for use in improving the production performance of yaks. PMID:29558395

ADAR1 regulates ARHGAP26 gene expression through RNA editing by disrupting miR-30b-3p and miR-573 binding.

PubMed

Wang, Qiong; Hui, Haipeng; Guo, Zhendong; Zhang, Weina; Hu, Yaou; He, Tao; Tai, Yanhong; Peng, Peng; Wang, Li

2013-11-01

Rho GTPase activating protein 26 (ARHGAP26) is a negative regulator of the Rho family that converts the small G proteins RhoA and Cdc42 to their inactive GDP-bound forms. It is essential for the CLIC/GEEC endocytic pathway, cell spreading, and muscle development. The present study shows that ARHGAP26 mRNA undergoes extensive A-to-I RNA editing in the 3' UTR that is specifically catalyzed by ADAR1. Furthermore, the mRNA and protein levels of ARHGAP26 were decreased in cells in which ADAR1 was knocked down. Conversely, ADAR1 overexpression increased the abundance of ARHGAP26 mRNA and protein. In addition, we found that both miR-30b-3p and miR-573 target the ARHGAP26 gene and that RNA editing of ARHGAP26 mediated by ADAR1 abolished the repression of its expression by miR-30b-3p or miR-573. When ADAR1 was overexpressed, the reduced abundance of ARHGAP26 protein mediated by miR-30b-3p or miR-573 was rescued. Importantly, we also found that knocking down ADAR1 elevated RhoA activity, which was consistent with the reduced level of ARHGAP26. Conversely, when ADAR1 was overexpressed, the amount of RhoA-GTP decreased. The similar expression patterns of ARHGAP26 and ADAR1 in human tissue samples further confirmed our findings. Taken together, our results suggest that ADAR1 regulates the expression of ARHGAP26 through A-to-I RNA editing by disrupting the binding of miR-30b-3p and miR-573 within the 3' UTR of ARHGAP26. This study provides a novel insight into the mechanism by which ADAR1 and its RNA editing function regulate microRNA-mediated modulation of target genes.

Mechanisms controlling neurite outgrowth in a pheochromocytoma cell line: The role of TRPC channels

PubMed Central

Kumar, Sanjay; Chakraborty, Saikat; Barbosa, Cindy; Brustovetsky, Tatiana; Brustovetsky, Nickolay; Obukhov, Alexander G.

2014-01-01

Transient Receptor Potential Canonical (TRPC) channels are implicated in modulating neurite outgrowth. The expression pattern of TRPC changes significantly during brain development, suggesting that fine-tuning TRPC expression may be important for orchestrating neuritogenesis. To study how alterations in the TRPC expression pattern affect neurite outgrowth, we used nerve growth factor (NGF)-differentiated rat pheochromocytoma 12 (PC12) cells, a model system for neuritogenesis. In PC12 cells, NGF markedly up-regulated TRPC1 and TRPC6 expression, but down-regulated TRPC5 expression while promoting neurite outgrowth. Overexpression of TRPC1 augmented, whereas TRPC5 overexpression decelerated NGF-induced neurite outgrowth. Conversely, shRNA-mediated knockdown of TRPC1 decreased, whereas shRNA-mediated knockdown of TRPC5 increased NGF-induced neurite extension. Endogenous TRPC1 attenuated the anti-neuritogenic effect of overexpressed TRPC5 in part by forming the heteromeric TRPC1–TRPC5 channels. Previous reports suggested that TRPC6 may facilitate neurite outgrowth. However, we found that TRPC6 overexpression slowed down neuritogenesis, whereas dominant negative TRPC6 (DN-TRPC6) facilitated neurite outgrowth in NGF-differentiated PC12 cells. Consistent with these findings, hyperforin, a neurite outgrowth promoting factor, decreased TRPC6 expression in NGF-differentiated PC12 cells. Using pharmacological and molecular biological approaches, we determined that NGF up-regulated TRPC1 and TRPC6 expression via a p75NTR-IKK2-dependent pathway that did not involve TrkA receptor signaling in PC12 cells. Similarly, NGF up-regulated TRPC1 and TRPC6 via an IKK2 dependent pathway in primary cultured hippocampal neurons. Thus, our data suggest that a balance of TRPC1, TRPC5, and TRPC6 expression determines neurite extension rate in neural cells, with TRPC6 emerging as an NGF-dependent “molecular damper” maintaining a submaximal velocity of neurite extension. PMID:21618530

p53 mutation and expression in lymphoma.

PubMed Central

Adamson, D. J.; Thompson, W. D.; Dawson, A. A.; Bennett, B.; Haites, N. E.

1995-01-01

Mutation and abnormal expression of p53 was studied in 38 lymphomas [five Hodgkin's disease and 33 non-Hodgkin's lymphoma (NHL)]. CM1 polyclonal antibody was used to detect overexpression of p53. Three missense mutations were characterised in three cases of NHL after screening exons 5-8 of p53 of all the tumours with single-strand conformation polymorphism (SSCP) analysis. Only two out of three tumours with a missense mutation showed abnormal expression of p53 as measured by CM1. Conversely, seven out of nine tumours with positive CM1 staining had no point mutation demonstrated. Overexpression of p53 in the cases of NHL occurred in three out of twenty four low-grade tumours and five out of nine high-grade tumours (Kiel classification). The results suggest that abnormalities of p53 are commoner in high-grade than low-grade NHL, and that positive immunocytochemistry cannot be used to determine which tumours have mutations of p53. Images Figure 1 Figure 2 PMID:7599045

Expression of Mitochondrial Cytochrome C Oxidase Chaperone Gene (COX20) Improves Tolerance to Weak Acid and Oxidative Stress during Yeast Fermentation

PubMed Central

Kumar, Vinod; Hart, Andrew J.; Keerthiraju, Ethiraju R.; Waldron, Paul R.; Tucker, Gregory A.; Greetham, Darren

2015-01-01

Introduction Saccharomyces cerevisiae is the micro-organism of choice for the conversion of fermentable sugars released by the pre-treatment of lignocellulosic material into bioethanol. Pre-treatment of lignocellulosic material releases acetic acid and previous work identified a cytochrome oxidase chaperone gene (COX20) which was significantly up-regulated in yeast cells in the presence of acetic acid. Results A Δcox20 strain was sensitive to the presence of acetic acid compared with the background strain. Overexpressing COX20 using a tetracycline-regulatable expression vector system in a Δcox20 strain, resulted in tolerance to the presence of acetic acid and tolerance could be ablated with addition of tetracycline. Assays also revealed that overexpression improved tolerance to the presence of hydrogen peroxide-induced oxidative stress. Conclusion This is a study which has utilised tetracycline-regulated protein expression in a fermentation system, which was characterised by improved (or enhanced) tolerance to acetic acid and oxidative stress. PMID:26427054

Glucose uptake and lactate production in cells exposed to CoCl(2) and in cells overexpressing the Glut-1 glucose transporter.

PubMed

Hwang, Daw-Yang; Ismail-Beigi, Faramarz

2002-03-15

Glut-1-mediated glucose transport is augmented in response to a variety of conditions and stimuli. In this study we examined the metabolic fate of glucose in cells in which glucose transport is stimulated by exposure to CoCl(2), an agent that stimulates the expression of a set of hypoxia-responsive genes including several glycolytic enzymes and the Glut-1 glucose transporter. Similarly, we determined the metabolic fate of glucose in stably transfected cells overexpressing Glut-1. Exposure of Clone 9 liver cell line, 3T3-L1 fibroblasts, and C(2)C(12) myoblasts to CoCl(2) resulted in an increase glucose uptake and in the activity of glucose phosphorylation ("hexokinase") and lactate dehydrogenase. In cells treated with CoCl(2), the net increase in glucose taken up was accounted for by its near-complete conversion to lactate. Cells stably transfected to overexpress Glut-1 also exhibited enhanced net uptake of glucose with the near-complete conversion of the increased glucose taken up to lactate; however, the effect in these cells was observed in the absence of any change in the activity of two glycolytic enzymes examined. These findings suggest that in cells in which glucose transport is rate-limiting for glucose metabolism, enhancement of the glucose entry step per se results in a near-complete conversion of the extra glucose to lactate.

C1q/TNF-related protein 6 (CTRP6) links obesity to adipose tissue inflammation and insulin resistance.

PubMed

Lei, Xia; Seldin, Marcus M; Little, Hannah C; Choy, Nicholas; Klonisch, Thomas; Wong, G William

2017-09-08

Obesity is associated with chronic low-grade inflammation, and metabolic regulators linking obesity to inflammation have therefore received much attention. Secreted C1q/TNF-related proteins (CTRPs) are one such group of regulators that regulate glucose and fat metabolism in peripheral tissues and modulate inflammation in adipose tissue. We have previously shown that expression of CTRP6 is up-regulated in leptin-deficient mice and, conversely, down-regulated by the anti-diabetic drug rosiglitazone. Here, we provide evidence for a novel role of CTRP6 in modulating both inflammation and insulin sensitivity. We found that in obese and diabetic humans and mouse models, CTRP6 expression was markedly up-regulated in adipose tissue and that stromal vascular cells, such as macrophages, are a major CTRP6 source. Overexpressing mouse or human CTRP6 impaired glucose disposal in peripheral tissues in response to glucose and insulin challenge in wild-type mice. Conversely, Ctrp6 gene deletion improved insulin action and increased metabolic rate and energy expenditure in diet-induced obese mice. Mechanistically, CTRP6 regulates local inflammation and glucose metabolism by targeting macrophages and adipocytes, respectively. In cultured macrophages, recombinant CTRP6 dose-dependently up-regulated the expression and production of TNF-α. Conversely, CTRP6 deficiency reduced circulating inflammatory cytokines and pro-inflammatory macrophages in adipose tissue. CTRP6-overexpressing mice or CTRP6-treated adipocytes had reduced insulin-stimulated Akt phosphorylation and glucose uptake. In contrast, loss of CTRP6 enhanced insulin-stimulated Akt activation in adipose tissue. Together, these results establish CTRP6 as a novel metabolic/immune regulator linking obesity to adipose tissue inflammation and insulin resistance. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Circular RNA HIPK3 promotes gallbladder cancer cell growth by sponging microRNA-124.

PubMed

Kai, Ding; Yannian, Liao; Yitian, Chen; Dinghao, Gong; Xin, Zhao; Wu, Ji

2018-06-18

Recent studies have implied that circHIPK3, an abundant circular RNA (circRNA), participates in tumorigenesis and cancer progression. Its expression and potential functions in human gallbladder cancer were examined in this study. We show that circHIPK3 is upregulated in human gallbladder cancer cells. But its level is low in gallbladder epithelial cells. circHIPK3 silencing by targeted siRNA potently inhibited survival and proliferation of established and primary human gallbladder cancer cells, while inducing cell apoptosis. Conversely, ectopic over-expression of circHIPK3 can further promote cancer cell proliferation. In gallbladder cancer cells, circHIPK3 sponged the tumor-suppressive microRNA-124 (miR-124) to sequester and inhibit its activity, thereby leading to increased expression of miR-124 targets, including ROCK1 (rho-associated protein kinase 1) and CDK6 (rho-associated protein kinase). Ectopic over-expression of miR-124 b y a lentiviral vector mimicked and abolished actions by circHIPK3 siRNA in gallbladder cancer cells. At last, we show that circHIPK3 is upregulated in human gallbladder cancer tissues, which is correlated with miR-124 downregulation and ROCK1-CDK6 upregulation. Together, we conclude that circHIPK3 promotes gallbladder cancer cell growth possibly by sponging miR-124. The over-expressed circHIPK3 could be a novel therapeutic target and diagnosis marker of human gallbladder cancer. Copyright © 2018. Published by Elsevier Inc.

Inhibition of Estrogen-Induced Growth of Breast Cancer by Targeting Mitochondria Oxidants

DTIC Science & Technology

2010-04-01

acetylcysteine (NAC) and ebselen], inhibits estrogen induced expression of cell cycle genes as well as prevention of estrogen-induced growth of malignant breast...have completed proposed research in the original First Task (i) both antioxidants, N- acetylcysteine and ebselen, overexpression of ROS lowering genes...bioassay to test whether estrogen-induced conversion of normal cells to transformed cells is inhibited by treatment with N- acetylcysteine and

Ste20-like kinase, SLK, activates the heat shock factor 1 - Hsp70 pathway.

PubMed

Cybulsky, Andrey V; Guillemette, Julie; Papillon, Joan

2016-09-01

Expression and activation of SLK increases during renal ischemia-reperfusion injury. When highly expressed, SLK signals via c-Jun N-terminal kinase and p38 to induce apoptosis, and it exacerbates apoptosis induced by ischemia-reperfusion injury. Overexpression of SLK in glomerular epithelial cells (GECs)/podocytes in vivo induces injury and proteinuria. In response to various stresses, cells enhance expression of chaperones or heat shock proteins (e.g. Hsp70), which are involved in the folding and maturation of newly synthesized proteins, and can refold denatured or misfolded proteins. We address the interaction of SLK with the heat shock factor 1 (HSF1)-Hsp70 pathway. Increased expression of SLK in GECs (following transfection) induced HSF1 transcriptional activity. Moreover, HSF1 transcriptional activity was increased by in vitro ischemia-reperfusion injury (chemical anoxia/recovery) and heat shock, and in both instances was amplified further by SLK overexpression. HSF1 binds to promoters of target genes, such as Hsp70 and induces their transcription. By analogy to HSF1, SLK stimulated Hsp70 expression. Hsp70 was also enhanced by anoxia/recovery and was further amplified by SLK overexpression. Induction of HSF1 and Hsp70 was dependent on the kinase activity of SLK, and was mediated via polo-like kinase-1. Transfection of constitutively active HSF1 enhanced Hsp70 expression and inhibited SLK-induced apoptosis. Conversely, the proapoptotic action of SLK was augmented by HSF1 shRNA, or the Hsp70 inhibitor, pifithrin-μ. In conclusion, increased expression/activity of SLK activates the HSF1-Hsp70 pathway. Hsp70 attenuates the primary proapoptotic effect of SLK. Modulation of chaperone expression may potentially be harnessed as cytoprotective therapy in renal cell injury. Copyright © 2016 Elsevier B.V. All rights reserved.

Cancer-associated fibroblasts promote cancer cell growth through a miR-7-RASSF2-PAR-4 axis in the tumor microenvironment

PubMed Central

Yan, Ming; Li, Rongrong; Chen, Gang; Zhang, Jianjun; Chen, Wantao

2017-01-01

Cancer-associated fibroblasts (CAFs), a major component of cancer stroma, play an important role in cancer progression but little is known about how CAFs affect tumorigenesis and development. MicroRNAs (miRNAs) are small non-coding RNAs that can negatively regulate target mRNA expression at post-transcriptional levels. In head and neck cancer (HNC), our analysis of miRNA arrays showed that miR-7, miR-196 and miR-335 were significantly up-regulated in CAFs when compared with their paired normal fibroblasts (NFs). FAP, α-SMA and FSP, specific markers of CAFs, were significantly expressed in CAFs. Functionally, exogenous expression of miR-7 in NFs induced a functional conversion of NFs into CAFs. In contrast, inhibition of miR-7 expression in CAFs could induce a functional conversion of CAFs into NFs. Our study demonstrated that overexpression of miR-7 in NFs significantly increased the migration activity and growth rates of cancer cells in co-culture experiments. Mechanistically, we confirmed that the RASSF2-PAR-4 axis was mainly responsible for miR-7 functions in CAFs using bioinformatics methods. Overexpression of miR-7 in CAFs led to down-regulation of RASSF2, which dramatically decreased the secretion of PAR-4 from CAFs and then enhanced the proliferation and migration of the co-cultured cancer cells. Thus, these results reveal that the inactivation of the RASSF2-PAR-4 axis controlled by miR-7 may be a novel strategy for gene therapy in HNCs. PMID:27901488

Overexpression of IRM1 Enhances Resistance to Aphids in Arabidopsis thaliana

PubMed Central

Chen, Xi; Zhang, Zhao; Visser, Richard G. F.; Broekgaarden, Colette; Vosman, Ben

2013-01-01

Aphids are insects that cause direct damage to crops by the removal of phloem sap, but more importantly they spread devastating viruses. Aphids use their sophisticated mouthpart (i.e. stylet) to feed from the phloem sieve elements of the host plant. To identify genes that affect host plant resistance to aphids, we previously screened an Arabidopsis thaliana activation tag mutant collection. In such mutants, tagged genes are overexpressed by a strong 35S enhancer adjacent to the natural promoter, resulting in a dominant gain-of-function phenotype. We previously identified several of these mutants on which the aphid Myzus persicae showed a reduced population development compared with wild type. In the present study we show that the gene responsible for the phenotype of one of the mutants is At5g65040 and named this gene Increased Resistance to Myzus persicae 1 (IRM1). Overexpression of the cloned IRM1 gene conferred a phenotype identical to that of the original mutant. Conversely, an IRM1 knockout mutant promoted aphid population development compared to the wild type. We performed Electrical Penetration Graph analysis to investigate how probing and feeding behaviour of aphids was affected on plants that either overexpressed IRM1 or contained a knockout mutation in this gene. The EPG results indicated that the aphids encounter resistance factors while reaching for the phloem on the overexpressing line. This resistance mechanism also affected other aphid species and is suggested to be of mechanical nature. Interestingly, genetic variation for IRM1 expression in response to aphid attack was observed. Upon aphid attack the expression of IRM1 was initially (after 6 hours) induced in ecotype Wassilewskija followed by suppression. In Columbia-0, IRM1 expression was already suppressed six hours after the start of the infestation. The resistance conferred by the overexpression of IRM1 in A. thaliana trades off with plant growth. PMID:23951039

Overexpression of the Arabidopsis thaliana signalling peptide TAXIMIN1 affects lateral organ development.

PubMed

Colling, Janine; Tohge, Takayuki; De Clercq, Rebecca; Brunoud, Geraldine; Vernoux, Teva; Fernie, Alisdair R; Makunga, Nokwanda P; Goossens, Alain; Pauwels, Laurens

2015-08-01

Lateral organ boundary formation is highly regulated by transcription factors and hormones such as auxins and brassinosteroids. However, in contrast to many other developmental processes in plants, no role for signalling peptides in the regulation of this process has been reported yet. The first characterization of the secreted cysteine-rich TAXIMIN (TAX) signalling peptides in Arabidopsis is presented here. TAX1 overexpression resulted in minor alterations in the primary shoot and root metabolome, abnormal fruit morphology, and fusion of the base of cauline leaves to stems forming a decurrent leaf attachment. The phenotypes at the paraclade junction match TAX1 promoter activity in this region and are similar to loss of LATERAL ORGAN FUSION (LOF) transcription factor function. Nevertheless, TAX1 expression was unchanged in lof1lof2 paraclade junctions and, conversely, LOF gene expression was unchanged in TAX1 overexpressing plants, suggesting TAX1 may act independently. This study identifies TAX1 as the first plant signalling peptide influencing lateral organ separation and implicates the existence of a peptide signal cascade regulating this process in Arabidopsis. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

PKCε promotes human Th17 differentiation: Implications in the pathophysiology of psoriasis.

PubMed

Martini, Silvia; Pozzi, Giulia; Carubbi, Cecilia; Masselli, Elena; Galli, Daniela; Di Nuzzo, Sergio; Banchini, Antonio; Gobbi, Giuliana; Vitale, Marco; Mirandola, Prisco

2018-04-01

PKCε is implicated in T cell activation and proliferation and is overexpressed in CD4 + -T cells from patients with autoimmune Hashimoto's thyroiditis. Although this might induce the suspicion that PKCε takes part in autoimmunity, its role in the molecular pathophysiology of immune-mediated disorders is still largely unknown. We studied PKCε expression in circulating CD4 + -T cells from patients with psoriasis, a skin disorder characterized by an increased amount of Th17 cells, a CD4 + subset that is critical in the development of autoimmunity. Although the mechanisms that underlie Th17 differentiation in humans are still unclear, we here show that: (i) PKCε is overexpressed in CD4 + -T cells from psoriatic patients, and its expression positively correlates with the severity of the disease, being reduced by effective phototherapy; (ii) PKCε interacts with Stat3 during Th17 differentiation and its overexpression results in an enhanced expression of Stat3 and pStat3(Ser727); iii) conversely, when PKCε is forcibly downregulated, CD4 + -T cells show lower levels of pStat3(Ser727) expression and defective in vitro expansion into the Th17-lineage. These data provide a novel insight into the molecular mechanisms of Th17 cell polarization that is known to play a crucial role in autoimmunity, pinpointing PKCε as a potential target in Th17-mediated diseases. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

McMYB12 Transcription Factors Co-regulate Proanthocyanidin and Anthocyanin Biosynthesis in Malus Crabapple

PubMed Central

Tian, Ji; Zhang, Jie; Han, Zhen-yun; Song, Ting-ting; Li, Jin-yan; Wang, Ya-ru; Yao, Yun-cong

2017-01-01

The flavonoid compounds, proanthocyanidins (PAs), protect plants from biotic stresses, contribute to the taste of many fruits, and are beneficial to human health in the form of dietary antioxidants. In this study, we functionally characterized two Malus crabapple R2R3-MYB transcription factors, McMYB12a and McMYB12b, which co-regulate PAs and anthocyanin biosynthesis. McMYB12a was shown to be mainly responsible for upregulating the expression of anthocyanin biosynthetic genes by binding to their promoters, but to be only partially responsible for regulating PAs biosynthetic genes. In contrast, McMYB12b showed preferential binding to the promoters of PAs biosynthetic genes. Overexpression of McMYB12a and McMYB12b in tobacco (Nicotiana tabacum) altered the expression of flavonoid biosynthetic genes and promoted the accumulation of PAs and anthocyanins in tobacco petals. Conversely, transient silencing their expression in crabapple plants, using a conserved gene region, resulted in reduced PAs and anthocyanin production a green leaf phenotype. Meanwhile, transient overexpression of the two genes and silenced McMYB12s in apple (Malus domestica) fruit had a similar effect as overexpression in tobacco and silenced in crabapple. This study reveals a new mechanism for the coordinated regulation of PAs and anthocyanin accumulation in crabapple leaves, which depends on an auto-regulatory balance involving McMYB12a and McMYB12b expression. PMID:28255171

McMYB12 Transcription Factors Co-regulate Proanthocyanidin and Anthocyanin Biosynthesis in Malus Crabapple.

PubMed

Tian, Ji; Zhang, Jie; Han, Zhen-Yun; Song, Ting-Ting; Li, Jin-Yan; Wang, Ya-Ru; Yao, Yun-Cong

2017-03-03

The flavonoid compounds, proanthocyanidins (PAs), protect plants from biotic stresses, contribute to the taste of many fruits, and are beneficial to human health in the form of dietary antioxidants. In this study, we functionally characterized two Malus crabapple R2R3-MYB transcription factors, McMYB12a and McMYB12b, which co-regulate PAs and anthocyanin biosynthesis. McMYB12a was shown to be mainly responsible for upregulating the expression of anthocyanin biosynthetic genes by binding to their promoters, but to be only partially responsible for regulating PAs biosynthetic genes. In contrast, McMYB12b showed preferential binding to the promoters of PAs biosynthetic genes. Overexpression of McMYB12a and McMYB12b in tobacco (Nicotiana tabacum) altered the expression of flavonoid biosynthetic genes and promoted the accumulation of PAs and anthocyanins in tobacco petals. Conversely, transient silencing their expression in crabapple plants, using a conserved gene region, resulted in reduced PAs and anthocyanin production a green leaf phenotype. Meanwhile, transient overexpression of the two genes and silenced McMYB12s in apple (Malus domestica) fruit had a similar effect as overexpression in tobacco and silenced in crabapple. This study reveals a new mechanism for the coordinated regulation of PAs and anthocyanin accumulation in crabapple leaves, which depends on an auto-regulatory balance involving McMYB12a and McMYB12b expression.

Notch3 overexpression causes arrest of cell cycle progression by inducing Cdh1 expression in human breast cancer cells.

PubMed

Chen, Chun-Fa; Dou, Xiao-Wei; Liang, Yuan-Ke; Lin, Hao-Yu; Bai, Jing-Wen; Zhang, Xi-Xun; Wei, Xiao-Long; Li, Yao-Chen; Zhang, Guo-Jun

2016-01-01

Uncontrolled cell proliferation, genomic instability and cancer are closely related to the abnormal activation of the cell cycle. Therefore, blocking the cell cycle of cancer cells has become one of the key goals for treating malignancies. Unfortunately, the factors affecting cell cycle progression remain largely unknown. In this study, we have explored the effects of Notch3 on the cell cycle in breast cancer cell lines by 3 methods: overexpressing the intra-cellular domain of Notch3 (N3ICD), knocking-down Notch3 by RNA interference, and using X-ray radiation exposure. The results revealed that overexpression of Notch3 arrested the cell cycle at the G0/G1 phase, and inhibited the proliferation and colony-formation rate in the breast cancer cell line, MDA-MB-231. Furthermore, overexpressing N3ICD upregulated Cdh1 expression and resulted in p27(Kip) accumulation by accelerating Skp2 degradation. Conversely, silencing of Notch3 in the breast cancer cell line, MCF-7, caused a decrease in expression levels of Cdh1 and p27(Kip) at both the protein and mRNA levels, while the expression of Skp2 only increased at the protein level. Correspondingly, there was an increase in the percentage of cells in the G0/G1 phase and an elevated proliferative ability and colony-formation rate, which may be caused by alterations of the Cdh1/Skp2/p27 axis. These results were also supported by exposing MDA-MB-231 cells or MCF-7 treated with siN3 to X-irradiation at various doses. Overall, our data showed that overexpression of N3ICD upregulated the expression of Cdh1 and caused p27(Kip) accumulation by accelerating Skp2 degradation, which in turn led to cell cycle arrest at the G0/G1 phase, in the context of proliferating breast cancer cell lines. These findings help to illuminate the precision therapy targeted to cell cycle progression, required for cancer treatment.

HDAC 1 and 6 modulate cell invasion and migration in clear cell renal cell carcinoma.

PubMed

Ramakrishnan, Swathi; Ku, ShengYu; Ciamporcero, Eric; Miles, Kiersten Marie; Attwood, Kris; Chintala, Sreenivasulu; Shen, Li; Ellis, Leigh; Sotomayor, Paula; Swetzig, Wendy; Huang, Ray; Conroy, Dylan; Orillion, Ashley; Das, Gokul; Pili, Roberto

2016-08-09

Class I histone deacetylases (HDACs) have been reported to be overexpressed in clear cell renal cell carcinoma (ccRCC), whereas the expression of class II HDACs is unknown. Four isogenic cell lines C2/C2VHL and 786-O/786-OVHL with differential VHL expression are used in our studies. Cobalt chloride is used to mimic hypoxia in vitro. HIF-2α knockdowns in C2 and 786-O cells is used to evaluate the effect on HDAC 1 expression and activity. Invasion and migration assays are used to investigate the role of HDAC 1 and HDAC 6 expression in ccRCC cells. Comparisons are made between experimental groups using the paired T-test, the two-sample Student's T-test or one-way ANOVA, as appropriate. ccRCC and the TCGA dataset are used to observe the clinical correlation between HDAC 1 and HDAC 6 overexpression and overall and progression free survival. Our analysis of tumor and matched non-tumor tissues from radical nephrectomies showed overexpression of class I and II HDACs (HDAC6 only in a subset of patients). In vitro, both HDAC1 and HDAC6 over-expression increased cell invasion and motility, respectively, in ccRCC cells. HDAC1 regulated invasiveness by increasing matrix metalloproteinase (MMP) expression. Furthermore, hypoxia stimulation in VHL-reconstituted cell lines increased HIF isoforms and HDAC1 expression. Presence of hypoxia response elements in the HDAC1 promoter along with chromatin immunoprecipitation data suggests that HIF-2α is a transcriptional regulator of HDAC1 gene. Conversely, HDAC6 and estrogen receptor alpha (ERα) were co-localized in cytoplasm of ccRCC cells and HDAC6 enhanced cell motility by decreasing acetylated α-tubulin expression, and this biological effect was attenuated by either biochemical or pharmacological inhibition. Finally, analysis of human ccRCC specimens revealed positive correlation between HIF isoforms and HDAC. HDAC1 mRNA upregulation was associated with worse overall survival in the TCGA dataset. Taking together, these results suggest that HDAC1 and HDAC6 may play a role in ccRCC biology and could represent rational therapeutic targets.

Dexamethasone treatment induces the reprogramming of pancreatic acinar cells to hepatocytes and ductal cells.

PubMed

Al-Adsani, Amani; Burke, Zoë D; Eberhard, Daniel; Lawrence, Katherine L; Shen, Chia-Ning; Rustgi, Anil K; Sakaue, Hiroshi; Farrant, J Mark; Tosh, David

2010-10-27

The pancreatic exocrine cell line AR42J-B13 can be reprogrammed to hepatocytes following treatment with dexamethasone. The question arises whether dexamethasone also has the capacity to induce ductal cells as well as hepatocytes. AR42J-B13 cells were treated with and without dexamethasone and analyzed for the expression of pancreatic exocrine, hepatocyte and ductal markers. Addition of dexamethasone inhibited pancreatic amylase expression, induced expression of the hepatocyte marker transferrin as well as markers typical of ductal cells: cytokeratin 7 and 19 and the lectin peanut agglutinin. However, the number of ductal cells was low compared to hepatocytes. The proportion of ductal cells was enhanced by culture with dexamethasone and epidermal growth factor (EGF). We established several features of the mechanism underlying the transdifferentiation of pancreatic exocrine cells to ductal cells. Using a CK19 promoter reporter, we show that a proportion of the ductal cells arise from differentiated pancreatic exocrine-like cells. We also examined whether C/EBPβ (a transcription factor important in the conversion of pancreatic cells to hepatocytes) could alter the conversion from acinar cells to a ductal phenotype. Overexpression of an activated form of C/EBPβ in dexamethasone/EGF-treated cells provoked the expression of hepatocyte markers and inhibited the expression of ductal markers. Conversely, ectopic expression of a dominant-negative form of C/EBPβ, liver inhibitory protein, inhibited hepatocyte formation in dexamethasone-treated cultures and enhanced the ductal phenotype. These results indicate that hepatocytes and ductal cells may be induced from pancreatic exocrine AR42J-B13 cells following treatment with dexamethasone. The conversion from pancreatic to hepatocyte or ductal cells is dependent upon the expression of C/EBPβ.

Effects of NADH-preferring xylose reductase expression on ethanol production from xylose in xylose-metabolizing recombinant Saccharomyces cerevisiae.

PubMed

Lee, Sung-Haeng; Kodaki, Tsutomu; Park, Yong-Cheol; Seo, Jin-Ho

2012-04-30

Efficient conversion of xylose to ethanol is an essential factor for commercialization of lignocellulosic ethanol. To minimize production of xylitol, a major by-product in xylose metabolism and concomitantly improve ethanol production, Saccharomyces cerevisiae D452-2 was engineered to overexpress NADH-preferable xylose reductase mutant (XR(MUT)) and NAD⁺-dependent xylitol dehydrogenase (XDH) from Pichia stipitis and endogenous xylulokinase (XK). In vitro enzyme assay confirmed the functional expression of XR(MUT), XDH and XK in recombinant S. cerevisiae strains. The change of wild type XR to XR(MUT) along with XK overexpression led to reduction of xylitol accumulation in microaerobic culture. More modulation of the xylose metabolism including overexpression of XR(MUT) and transaldolase, and disruption of the chromosomal ALD6 gene encoding aldehyde dehydrogenase (SX6(MUT)) improved the performance of ethanol production from xylose remarkably. Finally, oxygen-limited fermentation of S. cerevisiae SX6(MUT) resulted in 0.64 g l⁻¹ h⁻¹ xylose consumption rate, 0.25 g l⁻¹ h⁻¹ ethanol productivity and 39% ethanol yield based on the xylose consumed, which were 1.8, 4.2 and 2.2 times higher than the corresponding values of recombinant S. cerevisiae expressing XR(MUT), XDH and XK only. Copyright © 2011 Elsevier B.V. All rights reserved.

Seed-specific transcription factor HSFA9 links late embryogenesis and early photomorphogenesis

PubMed Central

Prieto-Dapena, Pilar; Almoguera, Concepción; Personat, José-María; Merchan, Francisco

2017-01-01

Abstract HSFA9 is a seed-specific transcription factor that in sunflower (Helianthus annuus) is involved in desiccation tolerance and longevity. Here we show that the constitutive overexpression of HSFA9 in tobacco (Nicotiana tabacum) seedlings attenuated hypocotyl growth under darkness and accelerated the initial photosynthetic development. Plants overexpressing HSFA9 increased accumulation of carotenoids, chlorophyllide, and chlorophyll, and displayed earlier unfolding of the cotyledons. HSFA9 enhanced phytochrome-dependent light responses, as shown by an intensified hypocotyl length reduction after treatments with continuous far-red or red light. This observation indicated the involvement of at least two phytochromes: PHYA and PHYB. Reduced hypocotyl length under darkness did not depend on phytochrome photo-activation; this was inferred from the lack of effect observed using far-red light pulses applied before the dark treatment. HSFA9 increased the expression of genes that activate photomorphogenesis, including PHYA, PHYB, and HY5. HSFA9 might directly upregulate PHYA and indirectly affect PHYB transcription, as suggested by transient expression assays. Converse effects on gene expression, greening, and cotyledon unfolding were observed using a dominant-negative form of HSFA9, which was overexpressed under a seed-specific promoter. This work uncovers a novel transcriptional link, through HSFA9, between seed maturation and early photomorphogenesis. In all, our data suggest that HSFA9 enhances photomorphogenesis via early transcriptional effects that start in seeds under darkness. PMID:28207924

Alteration of the Alkaloid Profile in Genetically Modified Tobacco Reveals a Role of Methylenetetrahydrofolate Reductase in Nicotine N-Demethylation1[C][W][OA

PubMed Central

Hung, Chiu-Yueh; Fan, Longjiang; Kittur, Farooqahmed S.; Sun, Kehan; Qiu, Jie; Tang, She; Holliday, Bronwyn M.; Xiao, Bingguang; Burkey, Kent O.; Bush, Lowell P.; Conkling, Mark A.; Roje, Sanja; Xie, Jiahua

2013-01-01

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme of the tetrahydrofolate (THF)-mediated one-carbon (C1) metabolic network. This enzyme catalyzes the reduction of 5,10-methylene-THF to 5-methyl-THF. The latter donates its methyl group to homocysteine, forming methionine, which is then used for the synthesis of S-adenosyl-methionine, a universal methyl donor for numerous methylation reactions, to produce primary and secondary metabolites. Here, we demonstrate that manipulating tobacco (Nicotiana tabacum) MTHFR gene (NtMTHFR1) expression dramatically alters the alkaloid profile in transgenic tobacco plants by negatively regulating the expression of a secondary metabolic pathway nicotine N-demethylase gene, CYP82E4. Quantitative real-time polymerase chain reaction and alkaloid analyses revealed that reducing NtMTHFR expression by RNA interference dramatically induced CYP82E4 expression, resulting in higher nicotine-to-nornicotine conversion rates. Conversely, overexpressing NtMTHFR1 suppressed CYP82E4 expression, leading to lower nicotine-to-nornicotine conversion rates. However, the reduced expression of NtMTHFR did not affect the methionine and S-adenosyl-methionine levels in the knockdown lines. Our finding reveals a new regulatory role of NtMTHFR1 in nicotine N-demethylation and suggests that the negative regulation of CYP82E4 expression may serve to recruit methyl groups from nicotine into the C1 pool under C1-deficient conditions. PMID:23221678

Decreased expression of SFRP2 promotes development of the pituitary corticotroph adenoma by upregulating Wnt signaling

PubMed Central

Sun, Yuhao; Pan, Sijian; Gu, Changwei; Chen, Xiao; Wang, Weiqing; Ning, Guang; Bian, Liuguan; Sun, Qingfang

2018-01-01

Cushing's disease is primarily caused by pituitary adrenocorticotropin-secreting adenoma. However, its pathogenesis has remained obscure. In the present study, whole transcriptome analysis was performed by RNA sequencing (RNA-Seq) and expression of secreted frizzled-related protein 2 (SFRP2) was decreased in corticotroph tumors compared with normal pituitary glands. Furthermore, the RNA-Seq results were validated and the expression of SFRP2 in tumor tissues was analyzed by comparing another cohort of 23 patients with Cushing's disease and 3 normal human pituitary samples using reverse transcription-quantitative polymerase chain reaction, western blot and immunohistochemistry staining. Clinically, there was an association between lower SFRP2 expression and aggressive adenoma characteristics, including larger size and invasiveness. Conversely, SFRP2 overexpression reduced the ability of AtT20 cells to proliferate and migrate, and reduced production of the adrenocorticotrophic hormone in vitro. Mechanistically, overexpressed SFRP2 reduced the level of β-catenin in the cytoplasm and nucleus, and decreased Wnt signaling activity in AtT20 cells. Therefore, SFRP2 appears to act as a tumor suppressor in Cushing's disease by regulating the activity of the Wnt signaling pathway. PMID:29620167

CMV-promoter driven codon-optimized expression alters the assembly type and morphology of a reconstituted HERV-K(HML-2).

PubMed

Hohn, Oliver; Hanke, Kirsten; Lausch, Veronika; Zimmermann, Anja; Mostafa, Saeed; Bannert, Norbert

2014-11-11

The HERV-K(HML-2) family contains the most recently integrated and best preserved endogenized proviral sequences in the human genome. All known elements have nevertheless been subjected to mutations or deletions that render expressed particles non-infectious. Moreover, these post-insertional mutations hamper the analysis of the general biological properties of this ancient virus family. The expression of consensus sequences and sequences of elements with reverted post-insertional mutations has therefore been very instrumental in overcoming this limitation. We investigated the particle morphology of a recently reconstituted HERV-K113 element termed oriHERV-K113 using thin-section electron microscopy (EM) and could demonstrate that strong overexpression by substitution of the 5'LTR for a CMV promoter and partial codon optimization altered the virus assembly type and morphology. This included a conversion from the regular C-type to an A-type morphology with a mass of cytoplasmic immature cores tethered to the cell membrane and the membranes of vesicles. Overexpression permitted the release and maturation of virions but reduced the envelope content. A weaker boost of virus expression by Staufen-1 was not sufficient to induce these morphological alterations.

CMV-Promoter Driven Codon-Optimized Expression Alters the Assembly Type and Morphology of a Reconstituted HERV-K(HML-2)

PubMed Central

Hohn, Oliver; Hanke, Kirsten; Lausch, Veronika; Zimmermann, Anja; Mostafa, Saeed; Bannert, Norbert

2014-01-01

The HERV-K(HML-2) family contains the most recently integrated and best preserved endogenized proviral sequences in the human genome. All known elements have nevertheless been subjected to mutations or deletions that render expressed particles non-infectious. Moreover, these post-insertional mutations hamper the analysis of the general biological properties of this ancient virus family. The expression of consensus sequences and sequences of elements with reverted post-insertional mutations has therefore been very instrumental in overcoming this limitation. We investigated the particle morphology of a recently reconstituted HERV-K113 element termed oriHERV-K113 using thin-section electron microscopy (EM) and could demonstrate that strong overexpression by substitution of the 5'LTR for a CMV promoter and partial codon optimization altered the virus assembly type and morphology. This included a conversion from the regular C-type to an A-type morphology with a mass of cytoplasmic immature cores tethered to the cell membrane and the membranes of vesicles. Overexpression permitted the release and maturation of virions but reduced the envelope content. A weaker boost of virus expression by Staufen-1 was not sufficient to induce these morphological alterations. PMID:25393897

Expression of matrix metalloproteinase 1, matrix metalloproteinase 2, and matrix metalloproteinase 9 in carcinoma of the head and neck.

PubMed

Franchi, Alessandro; Santucci, Marco; Masini, Emanuela; Sardi, Iacopo; Paglierani, Milena; Gallo, Oreste

2002-11-01

Numerous reports have documented a direct involvement of matrix metalloproteinase (MMP) overexpression in the development and progression of head and neck squamous cell carcinoma (HNSCC). In this study, the authors examined whether the expression of MMPs in HNSCC is correlated with other steps involved in tumor growth and metastasis, like angiogenesis, activation the nitric oxide (NO) pathway, and alteration of the p53 tumor suppressor gene. MMP-1, MMP-2, and MMP-9 expression levels were examined immunohistochemically in samples from 43 patients with HNSCC. Microvessel density (MVD) was determined by immunostaining of endothelial cells with anti-CD31 monoclonal antibody. Inducible nitric oxide synthase (iNOS) activity and cyclic guanosine monophosphatate (cGMP) levels were assessed in fresh tumor samples, whereas exons 5-9 of the p53 gene were analyzed by reverse transcriptase-polymerase chain reaction, single-strand conformation polymorphism analysis and were sequenced. MMP-1 overexpression (>10% of tumor cells) was identified in 32 tumors (74.5%), whereas elevated levels of MMP-2 and MMP-9 were detected in 17 tumors (39.5%) each. Tumors with MMP-9 overexpression were characterized by significantly higher MVD (P = 0.05) and significantly higher iNOS activity and cGMP levels (P = 0.005 and P = 0.02, respectively). Moreover, p53 mutation was associated strongly with MMP-9 overexpression (P = 0.004). Conversely, no correlation was found between MMP-1 and MMP-2 expression, angiogenesis, iNOS activity, cGMP levels, and p53 mutation in this series. This study documents the existence of a correlation between MMP-9 expression, activity of the iNOS pathway, p53 status, and angiogenesis in patients with HNSCC. This raises the possibility that p53 mutation, which frequently is present in HNSCC, may result in increased angiogenesis and invasiveness related to increased nitric oxide and MMP production by tumor cells, ultimately contributing to tumor progression. Copyright 2002 American Cancer Society.

Identification and overexpression of a knotted1-like transcription factor in switchgrass ( Panicum virgatum L.) for lignocellulosic feedstock improvement

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

Wuddineh, Wegi A.; Mazarei, Mitra; Zhang, Ji -Yi

High biomass production and wide adaptation has made switchgrass ( Panicum virgatum L.) an important candidate lignocellulosic bioenergy crop. One major limitation of this and other lignocellulosic feedstocks is the recalcitrance of complex carbohydrates to hydrolysis for conversion to biofuels. Lignin is the major contributor to recalcitrance as it limits the accessibility of cell wall carbohydrates to enzymatic breakdown into fermentable sugars. Therefore, genetic manipulation of the lignin biosynthesis pathway is one strategy to reduce recalcitrance. Here, we identified a switchgrass Knotted1 transcription factor, PvKN1, with the aim of genetically engineering switchgrass for reduced biomass recalcitrance for biofuel production. Genemore » expression of the endogenous PvKN1 gene was observed to be highest in young inflorescences and stems. Ectopic overexpression of PvKN1 in switchgrass altered growth, especially in early developmental stages. Transgenic lines had reduced expression of most lignin biosynthetic genes accompanied by a reduction in lignin content suggesting the involvement of PvKN1 in the broad regulation of the lignin biosynthesis pathway. Moreover, the reduced expression of the Gibberellin 20-oxidase (GA20ox) gene in tandem with the increased expression of Gibberellin 2-oxidase (GA2ox) genes in transgenic PvKN1 lines suggest that PvKN1 may exert regulatory effects via modulation of GA signaling. Furthermore, overexpression of PvKN1 altered the expression of cellulose and hemicellulose biosynthetic genes and increased sugar release efficiency in transgenic lines. Our findings demonstrated that switchgrass PvKN1 is a putative ortholog of maize KN1 that is linked to plant lignification and cell wall and development traits as a major regulatory gene. Therefore, targeted overexpression of PvKN1 in bioenergy feedstocks may provide one feasible strategy for reducing biomass recalcitrance and simultaneously improving plant growth characteristics.« less

Identification and overexpression of a knotted1-like transcription factor in switchgrass ( Panicum virgatum L.) for lignocellulosic feedstock improvement

DOE PAGES

Wuddineh, Wegi A.; Mazarei, Mitra; Zhang, Ji -Yi; ...

2016-04-28

High biomass production and wide adaptation has made switchgrass ( Panicum virgatum L.) an important candidate lignocellulosic bioenergy crop. One major limitation of this and other lignocellulosic feedstocks is the recalcitrance of complex carbohydrates to hydrolysis for conversion to biofuels. Lignin is the major contributor to recalcitrance as it limits the accessibility of cell wall carbohydrates to enzymatic breakdown into fermentable sugars. Therefore, genetic manipulation of the lignin biosynthesis pathway is one strategy to reduce recalcitrance. Here, we identified a switchgrass Knotted1 transcription factor, PvKN1, with the aim of genetically engineering switchgrass for reduced biomass recalcitrance for biofuel production. Genemore » expression of the endogenous PvKN1 gene was observed to be highest in young inflorescences and stems. Ectopic overexpression of PvKN1 in switchgrass altered growth, especially in early developmental stages. Transgenic lines had reduced expression of most lignin biosynthetic genes accompanied by a reduction in lignin content suggesting the involvement of PvKN1 in the broad regulation of the lignin biosynthesis pathway. Moreover, the reduced expression of the Gibberellin 20-oxidase (GA20ox) gene in tandem with the increased expression of Gibberellin 2-oxidase (GA2ox) genes in transgenic PvKN1 lines suggest that PvKN1 may exert regulatory effects via modulation of GA signaling. Furthermore, overexpression of PvKN1 altered the expression of cellulose and hemicellulose biosynthetic genes and increased sugar release efficiency in transgenic lines. Our findings demonstrated that switchgrass PvKN1 is a putative ortholog of maize KN1 that is linked to plant lignification and cell wall and development traits as a major regulatory gene. Therefore, targeted overexpression of PvKN1 in bioenergy feedstocks may provide one feasible strategy for reducing biomass recalcitrance and simultaneously improving plant growth characteristics.« less

Regulating ehrlich and demethiolation pathways for alcohols production by the expression of ubiquitin-protein ligase gene HUWE1.

PubMed

Zhang, Quan; Jia, Kai-Zhi; Xia, Shi-Tao; Xu, Yang-Hua; Liu, Rui-Sang; Li, Hong-Mei; Tang, Ya-Jie

2016-02-10

Ehrlich and demethiolation pathways as two competing branches converted amino acid into alcohols. Controlling both pathways offers considerable potential for industrial applications including alcohols overproduction, flavor-quality control and developing new flavors. While how to regulate ehrlich and demethiolation pathways is still not applicable. Taking the conversion of methionine into methionol and methanethiol for example, we constructed two suppression subtractive cDNA libraries of Clonostachys rosea by using suppression subtractive hybridization (SSH) technology for screening regulators controlling the conversion. E3 ubiquitin-protein ligase gene HUWE1 screened from forward SSH library was validated to be related with the biosynthesis of end products. Overexpressing HUWE1 in C. rosea and S. cerevisiae significantly increased the biosynthesis of methanethiol and its derivatives in demethiolation pathway, while suppressed the biosynthesis of methional and methionol in ehrlich pathway. These results attained the directional regulation of both pathways by overexpressing HUWE1. Thus, HUWE1 has potential to be a key target for controlling and enhancing alcohols production by metabolic engineering.

Keratin 23 promotes telomerase reverse transcriptase expression and human colorectal cancer growth.

PubMed

Zhang, Ningning; Zhang, Rui; Zou, Kun; Yu, Wendan; Guo, Wei; Gao, Yingying; Li, Jia; Li, Mei; Tai, Yidi; Huang, Wenlin; Song, Chun; Deng, Wuguo; Cui, Xiaonan

2017-07-27

The overexpression of human telomerase reverse transcriptase (hTERT) has been associated with the proliferation and migration of colorectal cancer (CRC) cells. We investigated the roles of KRT23 and hTERT in promoting CRC cell proliferation and migration. We verified the relationship between KRT23 and hTERT in CRC using streptavidin-agarose pulldown and chromatin immunoprecipitation (ChIP) assays. One hundred and fifty-four human CRC specimens were analyzed using immunohistochemistry. The roles of KRT23 and hTERT in cell growth and migration were studied using siRNA and lentiviruses in vivo and in vitro. Western blot and wound scratch analyses were used to determine the signaling pathway for KRT23-mediated activation of CRC growth and migration. Telomerase activity was measured by using the TeloTAGGG Telomerase PCR ELISA PLUS Kit. We identified KRT23 as a new hTERT promoter-binding protein. Patients with high KRT23 and hTERT expression had markedly shorter overall survival. Overexpression of KRT23 upregulated the expression of hTERT protein, hTERT promoter-driven luciferase and telomerase activity in CRC. Conversely, inhibition of KRT23 by a KRT23-specific siRNA repressed the endogenous hTERT protein, the expression of hTERT promoter-driven luciferase and telomerase activity. Overexpression of KRT23 also promoted CRC proliferation and migration. By contrast, KRT23 inhibition significantly inhibited tumor cell growth in vitro and in vivo. KRT23 promoted cancer stem cell properties and increased the expression of CD133 and CD44. These results demonstrate that KRT23 is an important cellular factor that promotes CRC growth by activating hTERT expression and that KRT23 is a potential novel therapeutic target for CRC.

Forced Hepatic Overexpression of CEACAM1 Curtails Diet-Induced Insulin Resistance

PubMed Central

Al-Share, Qusai Y.; DeAngelis, Anthony M.; Lester, Sumona Ghosh; Bowman, Thomas A.; Ramakrishnan, Sadeesh K.; Abdallah, Simon L.; Russo, Lucia; Patel, Payal R.; Kaw, Meenakshi K.; Raphael, Christian K.; Kim, Andrea Jung; Heinrich, Garrett; Lee, Abraham D.; Kim, Jason K.; Kulkarni, Rohit N.; Philbrick, William M.

2015-01-01

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) regulates insulin sensitivity by promoting hepatic insulin clearance. Liver-specific inactivation or global null-mutation of Ceacam1 impairs hepatic insulin extraction to cause chronic hyperinsulinemia, resulting in insulin resistance and visceral obesity. In this study we investigated whether diet-induced insulin resistance implicates changes in hepatic CEACAM1. We report that feeding C57/BL6J mice a high-fat diet reduced hepatic CEACAM1 levels by >50% beginning at 21 days, causing hyperinsulinemia, insulin resistance, and elevation in hepatic triacylglycerol content. Conversely, liver-specific inducible CEACAM1 expression prevented hyperinsulinemia and markedly limited insulin resistance and hepatic lipid accumulation that were induced by prolonged high-fat intake. This was partly mediated by increased hepatic β-fatty acid oxidation and energy expenditure. The data demonstrate that the high-fat diet reduced hepatic CEACAM1 expression and that overexpressing CEACAM1 in liver curtailed diet-induced metabolic abnormalities by protecting hepatic insulin clearance. PMID:25972571

COX2 expression and Erk1/Erk2 activity mediate Cot-induced cell migration.

PubMed

Rodríguez, Cristina; López, Pilar; Pozo, Maite; Duce, Antonio Martín; López-Pelaéz, Marta; Fernández, Margarita; Alemany, Susana

2008-09-01

The MAPKKK8 Cot/tpl-2, identified as an oncogene (Cot-T), participates in the intracellular signaling activated by members of the TLR and TNFalpha receptor superfamilies. Here we demonstrate that Cot promotes cell migration by regulating different steps involved in this process, such as cell adhesion and metalloproteinase activity. Indeed, Cot also regulates the cytoskeleton and Cot-T overexpression provokes the polarization of microtubules and the loss of stress fibers. Moreover, and in accordance with the increased Rac-GTP levels observed, Cot-T overexpressing cells develop more lamellipodia than control cells. Conversely, depletion of endogenous Cot increases the formation of stress fibers which is correlated with the high levels of Rho-GTP observed in these cells. In addition, the increase in COX2 expression and the activation of Erk1/2 regulated by Cot are essential for the induction of cell migration. Together, these data provide evidence of a new role for both proto-oncogenic and oncogenic Cot.

Overexpression of an alfalfa GDP-mannose 3, 5-epimerase gene enhances acid, drought and salt tolerance in transgenic Arabidopsis by increasing ascorbate accumulation.

PubMed

Ma, Lichao; Wang, Yanrong; Liu, Wenxian; Liu, Zhipeng

2014-11-01

GDP-mannose 3', 5'-epimerase (GME) catalyses the conversion of GDP-D-mannose to GDP-L-galactose, an important step in the ascorbic acid (ascorbic acid) biosynthetic pathway in higher plants. In this study, a novel cDNA fragment (MsGME) encoding a GME protein was isolated and characterised from alfalfa (Medicago sativa). An expression analysis confirmed that MsGME expression was induced by salinity, PEG and acidity stresses. MsGME overexpression in Arabidopsis enhanced tolerance of the transgenic plants to salt, drought and acid. Real-time PCR analysis revealed that the transcript levels of GDP-D-mannose pyrophosphorylase (GMP), L-galactose-phosphate 1-P phosphatase (GP) and GDP-L-galactose phosphorylase (GGP) were increased in transgenic Arabidopsis (T3 generation). Moreover, the ascorbate content was increased in transgenic Arabidopsis. Our results suggest that MsGME can effectively enhance tolerance of transgenic Arabidopsis to acid, drought and salt by increasing ascorbate accumulation.

The Relationship of Thioredoxin-1 and Cisplatin Resistance: Its Impact on ROS and Oxidative Metabolism in Lung Cancer Cells

PubMed Central

Wangpaichitr, Medhi; Theodoropoulos, George; Wu, Chunjing; You, Min; Feun, Lynn G.; Kuo, Macus T.; Savaraj, Niramol

2012-01-01

Elimination of cisplatin resistant (CR) lung cancer cells remains a major obstacle. We have shown that CR tumors have higher reactive oxygen species (ROS) levels and can be exploited for targeted therapy. Here we show that increased secretion of the antioxidant thioredoxin-1 (TRX1) resulted in lowered intracellular TRX1, and contributed to higher ROS in CR tumors in vivo and in vitro. By reconstitutingTRX1 protein in CR cells, we increased sensitivity to cisplatin but decreased sensitivity to elesclomol (ROS inducer). Conversely, decreased TRX1 protein in parental cells reduced the sensitivity to cisplatin but increased sensitivity to elesclomol. CR cells had increased endogenous oxygen consumption and mitochondrial activity but decreased lactic acid production. They also exhibited higher levels of argininosuccinate synthetase (ASS) and fumarase (FH) mRNA which contributed to oxidative metabolism (OXMET) when compared to parental cells. Restoring intracellular TRX1 protein in CR cells resulted in lowering ASS and FH mRNAs which in turn sensitized them to arginine deprivation. Interestingly, CR cells also possessed significantly higher basal levels of acetyl-CoA-carboxylase (ACC) and fatty acid synthase (FAS). Over-expressing TRX1 lowered ACC and FAS proteins expressions in CR cells. Chemical inhibition and siRNA of ACC resulted in significant cell death in CR compared to parental cells. Conversely, TRX1 over-expressed CR cells resisted to TOFA-induced death. Collectively, lowering TRX1 expression through increased secretion leads CR cells to higher ROS production and increase in dependency on OXMET. These changes raise an intriguing therapeutic potential for future therapy in cisplatin resistant lung cancer. PMID:22248473

Klotho down-regulates Egr-1 by inhibiting TGF-β1/Smad3 signaling in high glucose treated human mesangial cells

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

Li, Yang; Department of Geriatrics, Zhu Jiang Hospital, Southern Medical University, Guangzhou, Guangdong; Hu, Fang

Diabetic kidney disease (DKD) has become the leading cause of end-stage renal disease worldwide and is associated with glomerular mesangial cell (MC) proliferation and excessive extracellular matrix (ECM) production. Klotho can attenuate renal fibrosis in part by inhibiting TGF-β1/Smad3 signaling in DKD. Early growth response factor 1 (Egr-1) has been shown to play a key role in renal fibrosis in part by facilitating the formation of a positive feedback loop involving TGF-β1. However, whether Klotho down-regulates Egr-1 by inhibiting TGF-β1/Smad3 signaling in DKD is unclear. In the present study, we assessed human MCs that were incubated under high-glucose conditions tomore » mimic diabetes. Then, we transfected the cells with Klotho plasmid or siRNA to overexpress or knock down Klotho gene and protein expression. Klotho, Egr-1, fibronectin (FN), collagen type I (Col I), Smad3 and phosphorylated Smad3 (p-Smad3) gene and protein expression levels were determined by RT-qPCR and western blotting respectively. High glucose time-dependently down-regulated Klotho mRNA and protein expression in cultured human MCs. pcDNA3.1-Klotho transfection-mediated Klotho overexpression down-regulated Egr-1, FN and Col I expression and the p-Smad3/Smad3 ratio in human MCs. Conversely, siRNA-mediated Klotho silencing up-regulated Egr-1, FN, and Col I expression and the p-Smad3/Smad3 ratio. Moreover, the effects of si-Klotho on Egr-1 expression were abolished by the TGF-β1 inhibitor SB-431542. Klotho overexpression can prevent mesangial ECM production in high-glucose-treated human MCs, an effect that has been partially attributed to Egr-1 down-regulation facilitated by TGF-β1/Smad3 signaling inhibition. - Highlights: • High glucose time-dependently down-regulated Klotho mRNA and protein expression in cultured human MCs. • Klotho overexpression down-regulated Egr-1 and prevented mesangial ECM production in high-glucose-treated human MCs. • Klotho down-regulated Egr-1 by inhibiting TGF-β1/Smad3 signaling in high-glucose-treated human MCs.« less

SND2, a NAC transcription factor gene, regulates genes involved in secondary cell wall development in Arabidopsis fibres and increases fibre cell area in Eucalyptus

PubMed Central

2011-01-01

Background NAC domain transcription factors initiate secondary cell wall biosynthesis in Arabidopsis fibres and vessels by activating numerous transcriptional regulators and biosynthetic genes. NAC family member SND2 is an indirect target of a principal regulator of fibre secondary cell wall formation, SND1. A previous study showed that overexpression of SND2 produced a fibre cell-specific increase in secondary cell wall thickness in Arabidopsis stems, and that the protein was able to transactivate the cellulose synthase8 (CesA8) promoter. However, the full repertoire of genes regulated by SND2 is unknown, and the effect of its overexpression on cell wall chemistry remains unexplored. Results We overexpressed SND2 in Arabidopsis and analyzed homozygous lines with regards to stem chemistry, biomass and fibre secondary cell wall thickness. A line showing upregulation of CesA8 was selected for transcriptome-wide gene expression profiling. We found evidence for upregulation of biosynthetic genes associated with cellulose, xylan, mannan and lignin polymerization in this line, in agreement with significant co-expression of these genes with native SND2 transcripts according to public microarray repositories. Only minor alterations in cell wall chemistry were detected. Transcription factor MYB103, in addition to SND1, was upregulated in SND2-overexpressing plants, and we detected upregulation of genes encoding components of a signal transduction machinery recently proposed to initiate secondary cell wall formation. Several homozygous T4 and hemizygous T1 transgenic lines with pronounced SND2 overexpression levels revealed a negative impact on fibre wall deposition, which may be indirectly attributable to excessive overexpression rather than co-suppression. Conversely, overexpression of SND2 in Eucalyptus stems led to increased fibre cross-sectional cell area. Conclusions This study supports a function for SND2 in the regulation of cellulose and hemicellulose biosynthetic genes in addition of those involved in lignin polymerization and signalling. SND2 seems to occupy a subordinate but central tier in the secondary cell wall transcriptional network. Our results reveal phenotypic differences in the effect of SND2 overexpression between woody and herbaceous stems and emphasize the importance of expression thresholds in transcription factor studies. PMID:22133261

Toll-Like Receptor 4 (TLR4) and Triggering Receptor Expressed on Myeloid Cells-2 (TREM-2) Activation Balance Astrocyte Polarization into a Proinflammatory Phenotype.

PubMed

Rosciszewski, Gerardo; Cadena, Vanesa; Murta, Veronica; Lukin, Jeronimo; Villarreal, Alejandro; Roger, Thierry; Ramos, Alberto Javier

2018-05-01

Astrocytes react to brain injury with a generic response known as reactive gliosis, which involves activation of multiple intracellular pathways including several that may be beneficial for neuronal survival. However, by unknown mechanisms, reactive astrocytes can polarize into a proinflammatory phenotype that induces neurodegeneration. In order to study reactive gliosis and astroglial polarization into a proinflammatory phenotype, we used cortical devascularization-induced brain ischemia in Wistar rats and primary astroglial cell cultures exposed to oxygen-glucose deprivation (OGD). We analyzed the profile of TLR4 expression and the consequences of its activation by gain- and loss-of-function studies, and the effects produced by the activation of triggering receptor expressed on myeloid cells-2 (TREM-2), a negative regulator of TLR4 signaling. Both OGD exposure on primary astroglial cell cultures and cortical devascularization brain ischemia in rats induced TLR4 expression in astrocytes. In vivo, astroglial TLR4 expression was specifically observed in the ischemic penumbra surrounding necrotic core. Functional studies showed that OGD increased the astroglial response to the TLR4 agonist lipopolysaccharide (LPS), and conversely, TLR4 knockout primary astrocytes had impaired nuclear factor kappa-B (NF-κB) activation when exposed to LPS. In gain-of-function studies, plasmid-mediated TLR4 over-expression exacerbated astroglial response to LPS as shown by sustained NF-κB activation and increased expression of proinflammatory cytokines IL-1β and TNFα. TREM-2 expression, although present in naïve primary astrocytes, was induced by OGD, LPS, or high-mobility group box 1 protein (HMGB-1) exposure. TREM-2 activation by antibody cross-linking or the overexpression of TREM-2 intracellular adaptor, DAP12, partially suppressed LPS-induced NF-κB activation in purified astrocytic cultures. In vivo, TREM-2 expression was observed in macrophages and astrocytes located in the ischemic penumbra. While TREM-2+ macrophages were abundant at 3 days post-lesion (DPL) in the ischemic core, TREM-2+ astrocytes persisted in the penumbra until 14DPL. This study demonstrates that TLR4 expression increases astroglial sensitivity to ligands facilitating astrocyte conversion towards a proinflammatory phenotype, and that astroglial TREM-2 modulates this response reducing the downstream NF-κB activation. Therefore, the availability of TLR4 and TREM-2 ligands in the ischemic environment may control proinflammatory astroglial conversion to the neurodegenerative phenotype.

miR-132 and miR-212 are increased in pancreatic cancer and target the retinoblastoma tumor suppressor

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

Park, Jong-Kook; Henry, Jon C.; Jiang, Jinmai

2011-03-25

Research highlights: {yields} The expression of miR-132 and miR-212 are significantly increased in pancreatic cancer. {yields} miR-132 and miR-212 target the tumor suppressor pRb, resulting in enhanced proliferation. {yields} miR-132 and miR-212 expression is increased by a {beta}2 adrenergic receptor agonist, suggesting a novel mechanism for pancreatic cancer progression. -- Abstract: Numerous microRNAs (miRNAs) are reported as differentially expressed in cancer, however the consequence of miRNA deregulation in cancer is unknown for many miRNAs. We report that two miRNAs located on chromosome 17p13, miR-132 and miR-212, are over-expressed in pancreatic adenocarcinoma (PDAC) tissues. Both miRNAs are predicted to target themore » retinoblastoma tumor suppressor, Rb1. Validation of this interaction was confirmed by luciferase reporter assay and western blot in a pancreatic cancer cell line transfected with pre-miR-212 and pre-miR-132 oligos. Cell proliferation was enhanced in Panc-1 cells transfected with pre-miR-132/-212 oligos. Conversely, antisense oligos to miR-132/-212 reduced cell proliferation and caused a G{sub 2}/M cell cycle arrest. The mRNA of a number of E2F transcriptional targets were increased in cells over expressing miR-132/-212. Exposing Panc-1 cells to the {beta}2 adrenergic receptor agonist, terbutaline, increased the miR-132 and miR-212 expression by 2- to 4-fold. We report that over-expression of miR-132 and miR-212 result in reduced pRb protein in pancreatic cancer cells and that the increase in cell proliferation from over-expression of these miRNAs is likely due to increased expression of several E2F target genes. The {beta}2 adrenergic pathway may play an important role in this novel mechanism.« less

Importance of confirming HER2 overexpression of recurrence lesion in breast cancer patients.

PubMed

Nakamura, Rikiya; Yamamoto, Naohito; Onai, Yasuhide; Watanabe, Yoshihiro; Kawana, Hidetada; Miyazaki, Masaru

2013-10-01

The systemic management of metastatic breast cancer (MBC) is usually based on ER or HER2 status of the primary tumor. However, the hormonal status or the overexpression of human epidermal growth factor 2 (HER2) may change in every metastatic site because of the effects of the long-term treatment of metastatic cancer with endocrine therapy, chemotherapy, or biological agents. The purpose of this study was to investigate the frequency of change in HER2 expression in primary and distant metastatic tumors in breast cancer patients. Another objective of the study was to examine the effect of the clinical therapy on the basis of HER2 expression in a metastatic tumor. In our hospital between 1991 to December 2010, retrospectively, 156 patients had biopsy or surgical resection of their metastatic site. All sample were analyzed pathologically to confirm metastatic disease and, second, to evaluate HER2 status by immunohistochemistry or by FISH. The recurrence lesions were resected from the breast or lymph node (n = 67, local lesion), brain (n = 27), lung (n = 16), liver (n = 20), bone (n = 16), and from the stomach, intestine, ovary, and uterus (n = 10). Loss, increase, or no change in HER2 overexpression was observed in 3, 5, and 92%, respectively. Positive changes of HER2 in metastatic sites were 3 (4%) local lesion, 3 (11%) brain, 1 (7%) lung, 0 (0%) liver, 2 (17%) bone, and 0 (0%) others. In 3 of these 8 patients, trastuzumab was administered. In 2 of 3 patients, trastuzumab achieved long stable disease. The negative conversion rate of HER2 expression in metastatic lesions was 37% in patients treated with trastuzumab and 6% in those not treated with trastuzumab, a significant difference between the two groups (P < 0.05). The results of this study emphasize the significance of confirming HER2 expression in a recurrence lesion. For patients with positive conversion of HER2 status, more treatment options may be available. On the other hand, the rate of loss of HER2 expression was high in patients treated with trastuzumab, suggesting that the results of biopsy may provide an opportunity to reconsider treatment strategies for these patients.

Ectopic expression of a wheat WRKY transcription factor gene TaWRKY71-1 results in hyponastic leaves in Arabidopsis thaliana.

PubMed

Qin, Zhen; Lv, Hongjun; Zhu, Xinlei; Meng, Chen; Quan, Taiyong; Wang, Mengcheng; Xia, Guangmin

2013-01-01

Leaf type is an important trait that closely associates with crop yield. WRKY transcription factors exert diverse regulatory effects in plants, but their roles in the determination of leaf type have not been reported so far. In this work, we isolated a WRKY transcription factor gene TaWRKY71-1 from a wheat introgression line SR3, which has larger leaves, superior growth capacity and higher yield than its parent common wheat JN177. TaWRKY71-1 specifically expressed in leaves, and produced more mRNA in SR3 than in JN177. TaWRKY71-1 localized in the nucleus and had no transcriptional activation activity. TaWRKY71-1 overexpression in Arabidopsis resulted in hyponastic rosette leaves, and the hyponastic strength was closely correlative with the transcription level of the transgene. The spongy mesophyll cells at abaxial side of leaves were drastically compacted by TaWRKY71-1 overexpression. In TaWRKY71-1 overexpression Arabidopsis, the expression of IAMT1 that encodes a methyltransferase converting free indole-3-acetic acid (IAA) to methyl-IAA ester (MeIAA) to alter auxin homeostatic level was induced, and the induction level was dependent on the abundance of TaWRKY71-1 transcripts. Besides, several TCP genes that had found to be restricted by IAMT1 had lower expression levels as well. Our results suggest that TaWRKY71-1 causes hyponastic leaves through altering auxin homeostatic level by promoting the conversion of IAA to MeIAA.

Chloroplastic and cytoplasmic overexpression of sheep serotonin N-acetyltransferase in transgenic rice plants is associated with low melatonin production despite high enzyme activity.

PubMed

Byeon, Yeong; Lee, Hyoung Yool; Back, Kyoungwhan

2015-05-01

Serotonin N-acetyltransferase (SNAT), the penultimate enzyme in melatonin biosynthesis, catalyzes the conversion of serotonin into N-acetylserotonin. Plant SNAT is localized in chloroplasts. To test SNAT localization effects on melatonin synthesis, we generated transgenic rice plants overexpressing a sheep (Ovis aries) SNAT (OaSNAT) in their chloroplasts and compared melatonin biosynthesis with that of transgenic rice plants overexpressing OaSNAT in their cytoplasm. To localize the OaSNAT in chloroplasts, we used a chloroplast targeting sequence (CTS) from tobacco protoporphyrinogen IX oxidase (PPO), which expresses in chloroplasts. The purified recombinant CTS:OaSNAT fusion protein was enzymatically functional and localized in chloroplasts as confirmed by confocal microscopic analysis. The chloroplast-targeted CTS:OaSNAT lines and cytoplasm-expressed OaSNAT lines had similarly high SNAT enzyme activities. However, after cadmium and butafenacil treatments, melatonin production in rice leaves was severalfold lower in the CTS:OaSNAT lines than in the OaSNAT lines. Notably, enhanced SNAT enzyme activity was not directly proportional to the production of N-acetylserotonin, melatonin, or 2-hydroxymelatonin, suggesting that plant SNAT has a role in the homeostatic regulation of melatonin rather than in accelerating melatonin synthesis. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Endothelial-to-Osteoblast Conversion Generates Osteoblastic Metastasis of Prostate Cancer.

PubMed

Lin, Song-Chang; Lee, Yu-Chen; Yu, Guoyu; Cheng, Chien-Jui; Zhou, Xin; Chu, Khoi; Murshed, Monzur; Le, Nhat-Tu; Baseler, Laura; Abe, Jun-Ichi; Fujiwara, Keigi; deCrombrugghe, Benoit; Logothetis, Christopher J; Gallick, Gary E; Yu-Lee, Li-Yuan; Maity, Sankar N; Lin, Sue-Hwa

2017-06-05

Prostate cancer (PCa) bone metastasis is frequently associated with bone-forming lesions, but the source of the osteoblastic lesions remains unclear. We show that the tumor-induced bone derives partly from tumor-associated endothelial cells that have undergone endothelial-to-osteoblast (EC-to-OSB) conversion. The tumor-associated osteoblasts in PCa bone metastasis specimens and patient-derived xenografts (PDXs) were found to co-express endothelial marker Tie-2. BMP4, identified in PDX-conditioned medium, promoted EC-to-OSB conversion of 2H11 endothelial cells. BMP4 overexpression in non-osteogenic C4-2b PCa cells led to ectopic bone formation under subcutaneous implantation. Tumor-induced bone was reduced in trigenic mice (Tie2 cre /Osx f/f /SCID) with endothelial-specific deletion of osteoblast cell-fate determinant OSX compared with bigenic mice (Osx f/f /SCID). Thus, tumor-induced EC-to-OSB conversion is one mechanism that leads to osteoblastic bone metastasis of PCa. Copyright © 2017 Elsevier Inc. All rights reserved.

PXR-Mediated Upregulation of CYP3A Expression by Herb Compound Praeruptorin C from Peucedanum praeruptorum Dunn

PubMed Central

Huang, Ling; Wu, Qian; Li, Yu-Hua; Wang, Yi-Tao; Bi, Hui-Chang

2013-01-01

We recently reported that Praeruptorin C effectively transactivated the mRNA, protein expression, and catalytic activity of CYP3A4 via the CAR-mediated pathway, but whether and how PC could affect the expression and catalytic activity of CYP3A4 via PXR pathway remains unknown. Therefore, in this study, the effect of PC on the CYP3A gene expression was investigated in mice primary hepatocytes after knockdown of PXR by transient transfection of PXR siRNA, and the gene expression, protein expression, and catalytic activity of CYP3A4 in the LS174T cells with PXR overexpression were determined by real-time PCR, western blot analysis, and LC-MS/MS-based CYP3A4 substrate assay, respectively. We found that the level of CYP3a11 gene expression in mouse primary hepatocytes was significantly increased by praeruptorin C, but such an induction was suppressed after knockdown of pregnane X receptor by its siRNA. In PXR-overexpressed LS174T cells, PC significantly enhanced CYP3A4 mRNA, protein expression, and functional activity through PXR-mediated pathway; conversely, no such increase was found in the untransfected cells. These findings suggest that PC can significantly upregulate CYP3A level via the PXR-mediated pathway, and this should be taken into consideration to predict any potential herb-drug interactions between PC, Qianhu, and the other coadministered drugs. PMID:24379885

Teneurin-4 promotes cellular protrusion formation and neurite outgrowth through focal adhesion kinase signaling

PubMed Central

Suzuki, Nobuharu; Numakawa, Tadahiro; Chou, Joshua; de Vega, Susana; Mizuniwa, Chihiro; Sekimoto, Kaori; Adachi, Naoki; Kunugi, Hiroshi; Arikawa-Hirasawa, Eri; Yamada, Yoshihiko; Akazawa, Chihiro

2014-01-01

Teneurin-4 (Ten-4), a transmembrane protein, is highly expressed in the central nervous system; however, its cellular and molecular function in neuronal differentiation remains unknown. In this study, we aimed to elucidate the function of Ten-4 in neurite outgrowth. Ten-4 expression was induced during neurite outgrowth of the neuroblastoma cell line Neuro-2a. Ten-4 protein was localized at the neurite growth cones. Knockdown of Ten-4 expression in Neuro-2a cells decreased the formation of the filopodia-like protrusions and the length of individual neurites. Conversely, overexpression of Ten-4 promoted filopodia-like protrusion formation. In addition, knockdown and overexpression of Ten-4 reduced and elevated the activation of focal adhesion kinase (FAK) and Rho-family small GTPases, Cdc42 and Rac1, key molecules for the membranous protrusion formation downstream of FAK, respectively. Inhibition of the activation of FAK and neural Wiskott-Aldrich syndrome protein (N-WASP), which is a downstream regulator of FAK and Cdc42, blocked protrusion formation by Ten-4 overexpression. Further, Ten-4 colocalized with phosphorylated FAK in the filopodia-like protrusion regions. Together, our findings show that Ten-4 is a novel positive regulator of cellular protrusion formation and neurite outgrowth through the FAK signaling pathway.—Suzuki, N., Numakawa, T., Chou, J., de Vega, S., Mizuniwa, C., Sekimoto, K., Adachi, N., Kunugi, H., Arikawa-Hirasawa, E., Yamada, Y., Akazawa, C. Teneurin-4 promotes cellular protrusion formation and neurite outgrowth through focal adhesion kinase signaling. PMID:24344332

Higher miRNA Tolerance in Immortal Li-Fraumeni Fibroblasts with Abrogated Interferon Signaling Pathway

PubMed Central

Li, Qunfang; Tainsky, Michael A.

2013-01-01

The IFN pathway is abrogated in fibroblasts from Li-Fraumeni syndrome (LFS) patients during spontaneous cellular immortalization, a necessary step in carcinogenesis. Microarray profiling of differentially expressed microRNAs (miRNA) revealed that most miRNAs were upregulated in IFN pathway–defective MDAH087-10 fibroblasts compared with MDAH087-N cells with relatively normal IFN signaling. Overexpression of Dicer, a critical enzyme in miRNA biogenesis, promoted cell growth and colony formation in MDAH087-10 cells. However, double-stranded miRNA produced by Dicer enhanced the expression of IFN-stimulated genes in MDAH087-N cells resulting in significant cell death and reduced cell growth. Furthermore, manipulation of the IFN pathway in immortal LFS fibroblasts through transcription factor IRF7 reversed their response to Dicer overexpression due to changed IFN pathway activity. Dicer overexpressing MDAH087-N cells contained lower levels of miRNA than vector control, and conversely much higher miRNA expression was detected in Dicertransfected MDAH087-10 cells. Therefore, cells with a defective IFN pathway have a higher miRNA tolerance than cells with normal IFN pathway. This work indicates for the first time that the IFN pathway as mediated through the transcription factor IRF7 must be disrupted to permit miRNA upregulation to occur in early carcinogenesis. The IFN pathway appears to provide a checkpoint for miRNA level tolerance and its abrogation leads to cellular immortalization. PMID:21199806

Higher miRNA tolerance in immortal Li-Fraumeni fibroblasts with abrogated interferon signaling pathway.

PubMed

Li, Qunfang; Tainsky, Michael A

2011-01-01

The IFN pathway is abrogated in fibroblasts from Li-Fraumeni syndrome (LFS) patients during spontaneous cellular immortalization, a necessary step in carcinogenesis. Microarray profiling of differentially expressed microRNAs (miRNA) revealed that most miRNAs were upregulated in IFN pathway-defective MDAH087-10 fibroblasts compared with MDAH087-N cells with relatively normal IFN signaling. Overexpression of Dicer, a critical enzyme in miRNA biogenesis, promoted cell growth and colony formation in MDAH087-10 cells. However, double-stranded miRNA produced by Dicer enhanced the expression of IFN-stimulated genes in MDAH087-N cells resulting in significant cell death and reduced cell growth. Furthermore, manipulation of the IFN pathway in immortal LFS fibroblasts through transcription factor IRF7 reversed their response to Dicer overexpression due to changed IFN pathway activity. Dicer overexpressing MDAH087-N cells contained lower levels of miRNA than vector control, and conversely much higher miRNA expression was detected in Dicer-transfected MDAH087-10 cells. Therefore, cells with a defective IFN pathway have a higher miRNA tolerance than cells with normal IFN pathway. This work indicates for the first time that the IFN pathway as mediated through the transcription factor IRF7 must be disrupted to permit miRNA upregulation to occur in early carcinogenesis. The IFN pathway appears to provide a checkpoint for miRNA level tolerance and its abrogation leads to cellular immortalization. © 2011 AACR.

URI promotes gastric cancer cell motility, survival, and resistance to adriamycin in vitro.

PubMed

Hu, Xiaoxia; Zhang, Fei; Luo, Dongwei; Li, Na; Wang, Qian; Xu, Zhonghai; Bian, Huiqin; Liang, Yuting; Lu, Yaojuan; Zheng, Qiping; Gu, Junxia

2016-01-01

Unconventional prefoldin RPB5 interactor (URI), a RNA polymerase II Subunit 5-Interacting protein, is known to participate in the regulation of nutrient-sensitive mTOR-dependent transcription programs. Multiple studies have recently demonstrated that URI functions as an oncoprotein, possibly through the mTOR pathway, and regulates tumor cell motility, invasion, and metastasis. However, whether and how URI plays a role in gastric oncogenesis has not been elucidated. Due to drug resistance, recurrence and metastasis, the prognosis of gastric cancer remains poor. This study aims to explore the effects of URI on gastric cancer cells by focusing on their migratory ability and resistance to adriamycin. URI was over-expressed or knocked-down in MGC-803 and HGC-27 gastric cancer cells using URI plasmid or siRNA transfection approach. The cell viability, apoptosis, and migration ability were then examined by the CCK-8 assay, flow cytometer Annexin V/PI staining, and the Transwell cell migration assay respectively. The protein levels of apoptosis and EMT related genes were detected by western blot. The results showed that overexpression of URI promoted while knock-down of URI inhibited gastric cancer cell proliferation. URI overexpression resulted in increased Bcl-2 expression but decreased levels of Bax, cleaved PARP-1 and cleaved caspase-3. Conversely, cells treated with URI siRNA showed increased adriamycin induced apoptosis, along with reduced Bcl-2, but increased Bax, cleaved PARP-1 and cleaved caspase-3 expression. We have also shown that overexpression of URI enhanced cancer cell proliferation and migration with higher levels of Snail and Vimentin, whereas knockdown of URI in MGC-803 and HGC-27 cells inhibited proliferation and migration with decreased Snail and Vimentin expression. Together, our results support that URI promotes cell survival and mobility and acts as a chemotherapeutics resistant protein in MGC-803 and HGC-27 cells. URI might be a potential biomarker for gastric cancer diagnostics and prognostics.

miR-186 inhibits cell proliferation in multiple myeloma by repressing Jagged1

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

Liu, Zengyan; Department of Hematology, Hospital Affiliated to Binzhou Medical University, 661 Second Huanghe Street, Binzhou 256603; Zhang, Guoqiang

2016-01-15

MicroRNAs (miRNAs) are small, noncoding ribonucleic acids that regulate gene expression by targeting mRNAs for translational repression and degradation. Accumulating experimental evidence supports a causal role of miRNAs in hematology tumorigenesis. However, the specific functions of miRNAs in the pathogenesis of multiple myeloma (MM) remain to be established. In this study, we demonstrated that miR-186 is commonly downregulated in MM cell lines and patient MM cells. Ectopic expression of miR-186 significantly inhibited cell growth, both in vitro and in vivo, and induced cell cycle G{sub 0}/G{sub 1} arrest. Furthermore, miR-186 induced downregulation of Jagged1 protein expression by directly targeting its 3′-untranslated regionmore » (3′-UTR). Conversely, overexpression of Jagged1 rescued cells from miR-186-induced growth inhibition. Our collective results clearly indicate that miR-186 functions as a tumor suppressor in MM, supporting its potential as a therapeutic target for the disease. - Highlights: • miR-186 expression is decreased in MM. • miR-186 inhibits MM cell proliferation in vitro and in vivo. • Jagged1 is regulated by miR-186. • Overexpression of Jagged1 reverses the effects of miR-186.« less

EMX2 gene expression predicts liver metastasis and survival in colorectal cancer.

PubMed

Aykut, Berk; Ochs, Markus; Radhakrishnan, Praveen; Brill, Adrian; Höcker, Hermine; Schwarz, Sandra; Weissinger, Daniel; Kehm, Roland; Kulu, Yakup; Ulrich, Alexis; Schneider, Martin

2017-08-22

The Empty Spiracles Homeobox (EMX-) 2 gene has been associated with regulation of growth and differentiation in neuronal development. While recent studies provide evidence that EMX2 regulates tumorigenesis of various solid tumors, its role in colorectal cancer remains unknown. We aimed to assess the prognostic significance of EMX2 expression in stage III colorectal adenocarcinoma. Expression levels of EMX2 in human colorectal cancer and adjacent mucosa were assessed by qRT-PCR technology, and results were correlated with clinical and survival data. siRNA-mediated knockdown and adenoviral delivery-mediated overexpression of EMX2 were performed in order to investigate its effects on the migration of colorectal cancer cells in vitro. Compared to corresponding healthy mucosa, colorectal tumor samples had decreased EMX2 expression levels. Furthermore, EMX2 down-regulation in colorectal cancer tissue was associated with distant metastasis (M1) and impaired overall patient survival. In vitro knockdown of EMX2 resulted in increased tumor cell migration. Conversely, overexpression of EMX2 led to an inhibition of tumor cell migration. EMX2 is frequently down-regulated in human colorectal cancer, and down-regulation of EMX2 is a prognostic marker for disease-free and overall survival. EMX2 might thus represent a promising therapeutic target in colorectal cancer.

AMPKα2 regulates expression of estrogen-related receptor alpha, a metabolic transcription factor related to heart failure development

PubMed Central

Hu, Xinli; Xu, Xin; Lu, Zhongbing; Zhang, Ping; Fassett, John; Zhang, Ying; Xin, Yi; Hall, Jennifer L.; Viollet, Benoit; Bache, Robert J.; Huang, Yimin; Chen, Yingjie

2011-01-01

The normal expression of myocardial mitochondrial enzymes is essential to maintain the cardiac energy reserve and facilitate responses to stress, but the molecular mechanisms to maintain myocardial mitochondrial enzyme expression have been elusive. Here we report that congestive heart failure is associated with a significant decrease of myocardial Estrogen-Related Receptor alpha (ERRα), but not PPAR gamma coactivator-1 alpha (PGC1α), in human heart failure samples. In addition, chronic pressure overload in mice caused a decrease of ERRα expression that was significantly correlated to the degree of LV dysfunction, pulmonary congestion and decreases of a group of myocardial energy metabolism related genes. We found that the metabolic sensor AMP activated protein kinase (AMPK) regulates ERRα expression in vivo and in vitro. AMPKα2 KO decreased myocardial ERRα (both mRNA and protein) and its downstream targets under basal conditions, with no change in myocardial PGC1α expression. Using cultured rat neonatal cardiac myocytes, we found that overexpression of constitutively active AMPKα significantly induced ERRα mRNA, protein and promoter activity. Conversely, selective gene silencing of AMPKα2 repressed ERRα and its target gene levels, indicating that AMPKα2 is involved in the regulation of ERRα expression. In addition, over-expression of ERRα in AMPKα2 KO neonatal cardiac myocytes partially rescued the repressed expression of some energy metabolism related genes. These data support an important role for AMPKα2 in regulating the expression of myocardial ERRα and its downstream mitochondrial enzymes. PMID:21825219

The human cumulus--oocyte complex gene-expression profile

PubMed Central

Assou, Said; Anahory, Tal; Pantesco, Véronique; Le Carrour, Tanguy; Pellestor, Franck; Klein, Bernard; Reyftmann, Lionel; Dechaud, Hervé; De Vos, John; Hamamah, Samir

2006-01-01

BACKGROUND The understanding of the mechanisms regulating human oocyte maturation is still rudimentary. We have identified transcripts differentially expressed between immature and mature oocytes, and cumulus cells. METHODS Using oligonucleotides microarrays, genome wide gene expression was studied in pooled immature and mature oocytes or cumulus cells from patients who underwent IVF. RESULTS In addition to known genes such as DAZL, BMP15 or GDF9, oocytes upregulated 1514 genes. We show that PTTG3 and AURKC are respectively the securin and the Aurora kinase preferentially expressed during oocyte meiosis. Strikingly, oocytes overexpressed previously unreported growth factors such as TNFSF13/APRIL, FGF9, FGF14, and IL4, and transcription factors including OTX2, SOX15 and SOX30. Conversely, cumulus cells, in addition to known genes such as LHCGR or BMPR2, overexpressed cell-tocell signaling genes including TNFSF11/RANKL, numerous complement components, semaphorins (SEMA3A, SEMA6A, SEMA6D) and CD genes such as CD200. We also identified 52 genes progressively increasing during oocyte maturation, comprising CDC25A and SOCS7. CONCLUSION The identification of genes up and down regulated during oocyte maturation greatly improves our understanding of oocyte biology and will provide new markers that signal viable and competent oocytes. Furthermore, genes found expressed in cumulus cells are potential markers of granulosa cell tumors. PMID:16571642

Pleiotropic effect of sigE over-expression on cell morphology, photosynthesis and hydrogen production in Synechocystis sp. PCC 6803.

PubMed

Osanai, Takashi; Kuwahara, Ayuko; Iijima, Hiroko; Toyooka, Kiminori; Sato, Mayuko; Tanaka, Kan; Ikeuchi, Masahiko; Saito, Kazuki; Hirai, Masami Yokota

2013-11-01

Over-expression of sigE, a gene encoding an RNA polymerase sigma factor in the unicellular cyanobacterium Synechocystis sp. PCC 6803, is known to activate sugar catabolism and bioplastic production. In this study, we investigated the effects of sigE over-expression on cell morphology, photosynthesis and hydrogen production in this cyanobacterium. Transmission electron and scanning probe microscopic analyses revealed that sigE over-expression increased the cell size, possibly as a result of aberrant cell division. Over-expression of sigE reduced respiration and photosynthesis activities via changes in gene expression and chlorophyll fluorescence. Hydrogen production under micro-oxic conditions is enhanced in sigE over-expressing cells. Despite these pleiotropic phenotypes, the sigE over-expressing strain showed normal cell viability under both nitrogen-replete and nitrogen-depleted conditions. These results provide insights into the inter-relationship among metabolism, cell morphology, photosynthesis and hydrogen production in this unicellular cyanobacterium. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

Cultivation to improve in vivo solubility of overexpressed arginine deiminases in Escherichia coli and the enzyme characteristics.

PubMed

Wang, Ying; Li, Yue-Zhong

2014-06-07

Overexpression of foreign genes in Escherichia coli cells is an efficient means to obtain recombinant proteins. The technique is, however, often hampered by misfolding, degradation, aggregation and formation in inclusion bodies of products. In this study, we reported that in vivo solubility of overexpressed arginine deiminases (ADI) improved by changing the cultivation conditions. ADI is enzymes that convert L-arginine to L-citrulline. After codon optimization, we synthesized the ADI gene of Pseudomonas putida and constructed it for overexpression in E. coli cells. The rADI products were mainly in inclusion body forms. We performed a series of optimization to enhance solubility of the protein. Co-expression with the GroES-GroEL chaperone team increased approximately 5-fold of the rADI activity. In addition the combination of L-arginine and D-glucose in the Luria-Bertani (LB) growth medium further increased the total activity to about 15 times. Separate L-arginine and D-glucose or the addition of other saccharides or amino acids had no such effects. The solubilization effects of the combination of L-arginine and D-glucose were further confirmed in the overexpression of another ADI from Listeria welshimeri. The enzymatic and conversion characteristics of the rADI products were further determined. Combined addition of L-arginine and D-glucose in the LB medium significantly improved in vivo solubility of rADI proteins. The present study suggested a new strategy to increase the solubilization of overexpressed recombinant proteins in E. coli cells.

Photosynthetic conversion of CO2 to farnesyl diphosphate-derived phytochemicals (amorpha-4,11-diene and squalene) by engineered cyanobacteria.

PubMed

Choi, Sun Young; Lee, Hyun Jeong; Choi, Jaeyeon; Kim, Jiye; Sim, Sang Jun; Um, Youngsoon; Kim, Yunje; Lee, Taek Soon; Keasling, Jay D; Woo, Han Min

2016-01-01

Metabolic engineering of cyanobacteria has enabled photosynthetic conversion of CO2 to value-added chemicals as bio-solar cell factories. However, the production levels of isoprenoids in engineered cyanobacteria were quite low, compared to other microbial hosts. Therefore, modular optimization of multiple gene expressions for metabolic engineering of cyanobacteria is required for the production of farnesyl diphosphate-derived isoprenoids from CO2. Here, we engineered Synechococcus elongatus PCC 7942 with modular metabolic pathways consisting of the methylerythritol phosphate pathway enzymes and the amorphadiene synthase for production of amorpha-4,11-diene, resulting in significantly increased levels (23-fold) of amorpha-4,11-diene (19.8 mg/L) in the best strain relative to a parental strain. Replacing amorphadiene synthase with squalene synthase led to the synthesis of a high amount of squalene (4.98 mg/L/OD730). Overexpression of farnesyl diphosphate synthase is the most critical factor for the significant production, whereas overexpression of 1-deoxy-d-xylulose 5-phosphate reductase is detrimental to the cell growth and the production. Additionally, the cyanobacterial growth inhibition was alleviated by expressing a terpene synthase in S. elongatus PCC 7942 strain with the optimized MEP pathway only (SeHL33). This is the first demonstration of photosynthetic production of amorpha-4,11-diene from CO2 in cyanobacteria and production of squalene in S. elongatus PCC 7942. Our optimized modular OverMEP strain (SeHL33) with either co-expression of ADS or SQS demonstrated the highest production levels of amorpha-4,11-diene and squalene, which could expand the list of farnesyl diphosphate-derived isoprenoids from CO2 as bio-solar cell factories.

Slit/Robo1 signaling regulates neural tube development by balancing neuroepithelial cell proliferation and differentiation

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

Wang, Guang; Li, Yan; Wang, Xiao-yu

2013-05-01

Formation of the neural tube is the morphological hallmark for development of the embryonic central nervous system (CNS). Therefore, neural tube development is a crucial step in the neurulation process. Slit/Robo signaling was initially identified as a chemo-repellent that regulated axon growth cone elongation, but its role in controlling neural tube development is currently unknown. To address this issue, we investigated Slit/Robo1 signaling in the development of chick neCollege of Life Sciences Biocentre, University of Dundee, Dundee DD1 5EH, UKural tube and transgenic mice over-expressing Slit2. We disrupted Slit/Robo1 signaling by injecting R5 monoclonal antibodies into HH10 neural tubes tomore » block the Robo1 receptor. This inhibited the normal development of the ventral body curvature and caused the spinal cord to curl up into a S-shape. Next, Slit/Robo1 signaling on one half-side of the chick embryo neural tube was disturbed by electroporation in ovo. We found that the morphology of the neural tube was dramatically abnormal after we interfered with Slit/Robo1 signaling. Furthermore, we established that silencing Robo1 inhibited cell proliferation while over-expressing Robo1 enhanced cell proliferation. We also investigated the effects of altering Slit/Robo1 expression on Sonic Hedgehog (Shh) and Pax7 expression in the developing neural tube. We demonstrated that over-expressing Robo1 down-regulated Shh expression in the ventral neural tube and resulted in the production of fewer HNK-1{sup +} migrating neural crest cells (NCCs). In addition, Robo1 over-expression enhanced Pax7 expression in the dorsal neural tube and increased the number of Slug{sup +} pre-migratory NCCs. Conversely, silencing Robo1 expression resulted in an enhanced Shh expression and more HNK-1{sup +} migrating NCCs but reduced Pax7 expression and fewer Slug{sup +} pre-migratory NCCs were observed. In conclusion, we propose that Slit/Robo1 signaling is involved in regulating neural tube development by tightly coordinating cell proliferation and differentiation during neurulation. - Highlights: ► The role of Slit/Robo1 signaling was investigated with chick and mouse models. ► Disturbance of Slit/Robo1 signaling resulted in neural tube defects. ► Slit/Robo1 signaling regulated the proliferation of neural tube cells. ► Slit/Robo1 signaling modulated the differentiation of neural tube cells. ► Slit/Robo1 signaling balanced the proliferation and differentiation of neural tube.« less

DEAD-box helicase 27 promotes colorectal cancer growth and metastasis and predicts poor survival in CRC patients.

PubMed

Tang, Jieting; Chen, Huarong; Wong, Chi-Chun; Liu, Dabin; Li, Tong; Wang, Xiaohong; Ji, Jiafu; Sung, Joseph Jy; Fang, Jing-Yuan; Yu, Jun

2018-03-14

Copy number alterations (CNAs) are crucial for colorectal cancer (CRC) development. In this study, DEAD box polypeptide 27 (DDX27) was identified to be highly amplified in both TCGA CRC (474/615) and primary CRC (47/103), which was positively correlated with its mRNA overexpression. High DDX27 mRNA (N = 199) and protein expression (N = 260) predicted poor survival in CRC patients. Ectopic expression of DDX27 increased CRC cells proliferation, migration and invasion, but suppressed apoptosis. Conversely, silencing of DDX27 exerted opposite effects in vitro and significantly inhibited murine xenograft tumor growth and lung metastasis in vivo. Up-regulation of DDX27 enhanced and prolonged TNF-α-mediated NF-κB signaling. Nucleophosmin (NPM1) was identified as a binding partner of DDX27. DDX27 increased nuclear NPM1 and NF-κB-p65 interaction to enhance DNA binding activity of NF-κB. Silencing NPM1 abrogated DDX27-activating NF-κB signaling and its tumor-promoting function. Together, DDX27 is overexpressed and plays a pivotal oncogenic role in CRC.

Transgenic soybean overexpressing GmSAMT1 exhibits resistance to multiple-HG types of soybean cyst nematode Heterodera glycines

DOE PAGES

Lin, Jingyu; Mazarei, Mitra; Zhao, Nan; ...

2016-05-23

Soybean ( Glycine max (L.) Merr.) salicylic acid methyl transferase (GmSAMT1) catalyses the conversion of salicylic acid to methyl salicylate. Prior results showed that when GmSAMT1 was overexpressed in transgenic soybean hairy roots, resistance is conferred against soybean cyst nematode (SCN), Heterodera glycines Ichinohe. In this study, we produced transgenic soybean overexpressing GmSAMT1 and characterized their response to various SCN races. Transgenic plants conferred a significant reduction in the development of SCN HG type 1.2.5.7 (race 2), HG type 0 (race 3) and HG type 2.5.7 (race 5). Among transgenic lines, GmSAMT1 expression in roots was positively associated with SCNmore » resistance. In some transgenic lines, there was a significant decrease in salicylic acid titer relative to control plants. No significant seed yield differences were observed between transgenics and control soybean plants grown in one greenhouse with 22 °C day/night temperature, whereas transgenic soybean had higher yield than controls grown a warmer greenhouse (27 °C day/23 °C night) temperature. In a 1-year field experiment in Knoxville, TN, there was no significant difference in seed yield between the transgenic and nontransgenic soybean under conditions with negligible SCN infection. We hypothesize that GmSAMT1 expression affects salicylic acid biosynthesis, which, in turn, attenuates SCN development, without negative consequences to soybean yield or other morphological traits. Furthermore, we conclude that GmSAMT1 overexpression confers broad resistance to multiple SCN races, which would be potentially applicable to commercial production.« less

Transgenic soybean overexpressing GmSAMT1 exhibits resistance to multiple-HG types of soybean cyst nematode Heterodera glycines

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

Lin, Jingyu; Mazarei, Mitra; Zhao, Nan

Soybean ( Glycine max (L.) Merr.) salicylic acid methyl transferase (GmSAMT1) catalyses the conversion of salicylic acid to methyl salicylate. Prior results showed that when GmSAMT1 was overexpressed in transgenic soybean hairy roots, resistance is conferred against soybean cyst nematode (SCN), Heterodera glycines Ichinohe. In this study, we produced transgenic soybean overexpressing GmSAMT1 and characterized their response to various SCN races. Transgenic plants conferred a significant reduction in the development of SCN HG type 1.2.5.7 (race 2), HG type 0 (race 3) and HG type 2.5.7 (race 5). Among transgenic lines, GmSAMT1 expression in roots was positively associated with SCNmore » resistance. In some transgenic lines, there was a significant decrease in salicylic acid titer relative to control plants. No significant seed yield differences were observed between transgenics and control soybean plants grown in one greenhouse with 22 °C day/night temperature, whereas transgenic soybean had higher yield than controls grown a warmer greenhouse (27 °C day/23 °C night) temperature. In a 1-year field experiment in Knoxville, TN, there was no significant difference in seed yield between the transgenic and nontransgenic soybean under conditions with negligible SCN infection. We hypothesize that GmSAMT1 expression affects salicylic acid biosynthesis, which, in turn, attenuates SCN development, without negative consequences to soybean yield or other morphological traits. Furthermore, we conclude that GmSAMT1 overexpression confers broad resistance to multiple SCN races, which would be potentially applicable to commercial production.« less

Thyroid hormone regulates muscle fiber type conversion via miR-133a1.

PubMed

Zhang, Duo; Wang, Xiaoyun; Li, Yuying; Zhao, Lei; Lu, Minghua; Yao, Xuan; Xia, Hongfeng; Wang, Yu-Cheng; Liu, Mo-Fang; Jiang, Jingjing; Li, Xihua; Ying, Hao

2014-12-22

It is known that thyroid hormone (TH) is a major determinant of muscle fiber composition, but the molecular mechanism by which it does so remains unclear. Here, we demonstrated that miR-133a1 is a direct target gene of TH in muscle. Intriguingly, miR-133a, which is enriched in fast-twitch muscle, regulates slow-to-fast muscle fiber type conversion by targeting TEA domain family member 1 (TEAD1), a key regulator of slow muscle gene expression. Inhibition of miR-133a in vivo abrogated TH action on muscle fiber type conversion. Moreover, TEAD1 overexpression antagonized the effect of miR-133a as well as TH on muscle fiber type switch. Additionally, we demonstrate that TH negatively regulates the transcription of myosin heavy chain I indirectly via miR-133a/TEAD1. Collectively, we propose that TH inhibits the slow muscle phenotype through a novel epigenetic mechanism involving repression of TEAD1 expression via targeting by miR-133a1. This identification of a TH-regulated microRNA therefore sheds new light on how TH achieves its diverse biological activities. © 2014 Zhang et al.

Thyroid hormone regulates muscle fiber type conversion via miR-133a1

PubMed Central

Zhang, Duo; Wang, Xiaoyun; Li, Yuying; Zhao, Lei; Lu, Minghua; Yao, Xuan; Xia, Hongfeng; Wang, Yu-cheng; Liu, Mo-Fang; Jiang, Jingjing; Li, Xihua

2014-01-01

It is known that thyroid hormone (TH) is a major determinant of muscle fiber composition, but the molecular mechanism by which it does so remains unclear. Here, we demonstrated that miR-133a1 is a direct target gene of TH in muscle. Intriguingly, miR-133a, which is enriched in fast-twitch muscle, regulates slow-to-fast muscle fiber type conversion by targeting TEA domain family member 1 (TEAD1), a key regulator of slow muscle gene expression. Inhibition of miR-133a in vivo abrogated TH action on muscle fiber type conversion. Moreover, TEAD1 overexpression antagonized the effect of miR-133a as well as TH on muscle fiber type switch. Additionally, we demonstrate that TH negatively regulates the transcription of myosin heavy chain I indirectly via miR-133a/TEAD1. Collectively, we propose that TH inhibits the slow muscle phenotype through a novel epigenetic mechanism involving repression of TEAD1 expression via targeting by miR-133a1. This identification of a TH-regulated microRNA therefore sheds new light on how TH achieves its diverse biological activities. PMID:25512392

JAG1-Mediated Notch Signaling Regulates Secretory Cell Differentiation of the Human Airway Epithelium.

PubMed

Gomi, Kazunori; Staudt, Michelle R; Salit, Jacqueline; Kaner, Robert J; Heldrich, Jonna; Rogalski, Allison M; Arbelaez, Vanessa; Crystal, Ronald G; Walters, Matthew S

2016-08-01

Basal cells (BC) are the stem/progenitor cells of the human airway epithelium capable of differentiating into secretory and ciliated cells. Notch signaling activation increases BC differentiation into secretory cells, but the role of individual Notch ligands in regulating this process in the human airway epithelium is largely unknown. The objective of this study was to define the role of the Notch ligand JAG1 in regulating human BC differentiation. JAG1 over-expression in BC increased secretory cell differentiation, with no effect on ciliated cell differentiation. Conversely, knockdown of JAG1 decreased expression of secretory cell genes. These data demonstrate JAG1-mediated Notch signaling regulates differentiation of BC into secretory cells.

Phosphoketolase overexpression increases biomass and lipid yield from methane in an obligate methanotrophic biocatalyst

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

Henard, Calvin A.; Smith, Holly K.; Guarnieri, Michael T.

Microbial conversion of methane to high-value bio-based chemicals and materials offers a path to mitigate GHG emissions and valorize this abundant-yet -underutilized carbon source. In addition to fermentation optimization strategies, rational methanotrophic bacterial strain engineering offers a means to reach industrially relevant titers, carbon yields, and productivities of target products. The phosphoketolase pathway functions in heterofermentative bacteria where carbon flux through two sugar catabolic pathways to mixed acids (lactic acid and acetic acid) increases cellular ATP production. Importantly, this pathway also serves as an alternative route to produce acetyl-CoA that bypasses the CO 2 lost through pyruvate decarboxylation in themore » Embden-Meyerhof-Parnas pathway. Thus, the phosphoketolase pathway can be leveraged for carbon efficient biocatalysis to acetyl-CoA-derived intermediates and products. Here, we show that the industrially promising methane biocatalyst, Methylomicrobium buryatense, encodes two phosphoketolase isoforms that are expressed in methanol- and methane-grown cells. Overexpression of the PktB isoform led to a 2-fold increase in intracellular acetyl-CoA concentration, and a 2.6-fold yield enhancement from methane to microbial biomass and lipids compared to wild-type, increasing the potential for methanotroph lipid-based fuel production. Off-gas analysis and metabolite profiling indicated that global metabolic rearrangements, including significant increases in post-translational protein acetylation and gene expression of the tetrahydromethanopterin-linked pathway, along with decreases in several excreted products, coincided with the superior biomass and lipid yield observed in the engineered strain. Further, these data suggest that phosphoketolase may play a key regulatory role in methanotrophic bacterial metabolism. As a result, given that acetyl-CoA is a key intermediate in several biosynthetic pathways, phosphoketolase overexpression offers a viable strategy to enhance the economics of an array of biological methane conversion processes.« less

Phosphoketolase overexpression increases biomass and lipid yield from methane in an obligate methanotrophic biocatalyst.

PubMed

Henard, Calvin A; Smith, Holly K; Guarnieri, Michael T

2017-05-01

Microbial conversion of methane to high-value bio-based fuels, chemicals, and materials offers a path to mitigate GHG emissions and valorize this abundant-yet -underutilized carbon source. In addition to fermentation optimization strategies, rational methanotrophic bacterial strain engineering offers a means to reach industrially relevant titers, carbon yields, and productivities of target products. The phosphoketolase pathway functions in heterofermentative bacteria where carbon flux through two sugar catabolic pathways to mixed acids (lactic acid and acetic acid) increases cellular ATP production. Importantly, this pathway also serves as an alternative route to produce acetyl-CoA that bypasses the CO 2 lost through pyruvate decarboxylation in the Embden-Meyerhof-Parnas pathway. Thus, the phosphoketolase pathway can be leveraged for carbon efficient biocatalysis to acetyl-CoA-derived intermediates and products. Here, we show that the industrially promising methane biocatalyst, Methylomicrobium buryatense, encodes two phosphoketolase isoforms that are expressed in methanol- and methane-grown cells. Overexpression of the PktB isoform led to a 2-fold increase in intracellular acetyl-CoA concentration, and a 2.6-fold yield enhancement from methane to microbial biomass and lipids compared to wild-type, increasing the potential for methanotroph lipid-based fuel production. Off-gas analysis and metabolite profiling indicated that global metabolic rearrangements, including significant increases in post-translational protein acetylation and gene expression of the tetrahydromethanopterin-linked pathway, along with decreases in several excreted products, coincided with the superior biomass and lipid yield observed in the engineered strain. Further, these data suggest that phosphoketolase may play a key regulatory role in methanotrophic bacterial metabolism. Given that acetyl-CoA is a key intermediate in several biosynthetic pathways, phosphoketolase overexpression offers a viable strategy to enhance the economics of an array of biological methane conversion processes. Copyright © 2017. Published by Elsevier Inc.

Phosphoketolase overexpression increases biomass and lipid yield from methane in an obligate methanotrophic biocatalyst

DOE PAGES

Henard, Calvin A.; Smith, Holly K.; Guarnieri, Michael T.

2017-04-02

Microbial conversion of methane to high-value bio-based chemicals and materials offers a path to mitigate GHG emissions and valorize this abundant-yet -underutilized carbon source. In addition to fermentation optimization strategies, rational methanotrophic bacterial strain engineering offers a means to reach industrially relevant titers, carbon yields, and productivities of target products. The phosphoketolase pathway functions in heterofermentative bacteria where carbon flux through two sugar catabolic pathways to mixed acids (lactic acid and acetic acid) increases cellular ATP production. Importantly, this pathway also serves as an alternative route to produce acetyl-CoA that bypasses the CO 2 lost through pyruvate decarboxylation in themore » Embden-Meyerhof-Parnas pathway. Thus, the phosphoketolase pathway can be leveraged for carbon efficient biocatalysis to acetyl-CoA-derived intermediates and products. Here, we show that the industrially promising methane biocatalyst, Methylomicrobium buryatense, encodes two phosphoketolase isoforms that are expressed in methanol- and methane-grown cells. Overexpression of the PktB isoform led to a 2-fold increase in intracellular acetyl-CoA concentration, and a 2.6-fold yield enhancement from methane to microbial biomass and lipids compared to wild-type, increasing the potential for methanotroph lipid-based fuel production. Off-gas analysis and metabolite profiling indicated that global metabolic rearrangements, including significant increases in post-translational protein acetylation and gene expression of the tetrahydromethanopterin-linked pathway, along with decreases in several excreted products, coincided with the superior biomass and lipid yield observed in the engineered strain. Further, these data suggest that phosphoketolase may play a key regulatory role in methanotrophic bacterial metabolism. As a result, given that acetyl-CoA is a key intermediate in several biosynthetic pathways, phosphoketolase overexpression offers a viable strategy to enhance the economics of an array of biological methane conversion processes.« less

CacyBP/SIP as a regulator of transcriptional responses in brain cells

PubMed Central

Kilanczyk, Ewa; Filipek, Anna; Hetman, Michal

2014-01-01

Summary The Calcyclin-Binding Protein/Siah-1-Interacting Protein (CacyBP/SIP) is highly expressed in the brain and was shown to regulate the β-catenin-driven transcription in thymocytes. Therefore, it was investigated whether in brain cells CacyBP/SIP might play a role as a transcriptional regulator. In BDNF- or forskolin-stimulated rat primary cortical neurons, overexpression of CacyBP/SIP enhanced transcriptional activity of the cAMP-response element (CRE). In addition, overexpressed CacyBP/SIP enhanced BDNF-mediated activation of the Nuclear Factor of Activated T-cells (NFAT) but not the Serum Response Element (SRE). These stimulatory effects required an intact C-terminal domain of CacyBP/SIP. Moreover, in C6 rat glioma cells, the overexpressed CacyBP/SIP enhanced activation of CRE- or NFAT- following forskolin- or serum stimulation, respectively. Conversely, knockdown of endogenous CacyBP/SIP reduced activation of CRE- and NFAT but not SRE. Taken together, these results indicate that CacyBP/SIP is a novel regulator of CRE- and NFAT-driven transcription. PMID:25163685

Phosphofructokinase-P Modulates P44/42 MAPK Levels in HeLa Cells.

PubMed

Cardim Pires, Thyago Rubens; Albanese, Jamille Mansur; Schwab, Michael; Marette, André; Carvalho, Renato Sampaio; Sola-Penna, Mauro; Zancan, Patricia

2017-05-01

It is known that interfering with glycolysis leads to profound modification of cancer cell proliferation. However, energy production is not the major reason for this correlation. Here, using HeLa cells as a model for cancer, we demonstrate that phosphofructokinase-P (PFK-P), which is overexpressed in diverse types of cancer including HeLa cells, modulates expression of P44/42 mitogen-activated protein kinase (MAPK). Silencing of PFK-P did not alter HeLa cell viability or energy production, including the glycolytic rate. On the other hand, silencing of PFK-P induced the downregulation of p44/42 MAPK, augmenting the sensitivity of HeLa cells to different drugs. Conversely, overexpression of PFK-P promotes the upregulation of p44/42 MAPK, making the cells more resistant to the drugs. These results indicate that overexpression of PFK-P by cancer cells is related to activation of survival pathways via upregulation of MAPK and suggest PFK-P as a promising target for cancer therapy. J. Cell. Biochem. 118: 1216-1226, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Positive feedback regulation of a Lycium chinense-derived VDE gene by drought-induced endogenous ABA, and over-expression of this VDE gene improve drought-induced photo-damage in Arabidopsis.

PubMed

Guan, Chunfeng; Ji, Jing; Zhang, Xuqiang; Li, Xiaozhou; Jin, Chao; Guan, Wenzhu; Wang, Gang

2015-03-01

Violaxanthin de-epoxidase (VDE) plays an important role in protecting the photosynthetic apparatus from photo-damage by dissipating excessively absorbed light energy as heat, via the conversion of violaxanthin (V) to intermediate product antheraxanthin (A) and final product zeaxanthin (Z) under light stress. We have cloned a VDE gene (LcVDE) from Lycium chinense, a deciduous woody perennial halophyte, which can grow in a large variety of soil types. The amino acid sequence of LcVDE has high homology with VDEs in other plants. Under drought stress, relative expression of LcVDE and the de-epoxidation ratio (Z+0.5A)/(V+A+Z) increased rapidly, and non-photochemical quenching (NPQ) also rose. Interestingly, these elevations induced by drought stress were reduced by the topical administration of abamine SG, a potent ABA inhibitor via inhibition of NCED in the ABA synthesis pathway. Until now, little has been done to explore the relationship between endogenous ABA and the expression of VDE genes. Since V serves as a common precursor for ABA, these data support the possible involvement of endogenous ABA in the positive feedback regulation of LcVDE gene expression in L. chinense under drought stress. Moreover, the LcVDE may be involved in modulating the level of photosynthesis damage caused by drought stress. Furthermore, the ratio of (Z+0.5A)/(V+A+Z) and NPQ increased more in transgenic Arabidopsis over-expressing LcVDE gene than the wild types under drought stress. The maximum quantum yield of primary photochemistry of PSII (Fv/Fm) in transgenic Arabidopsis decreased more slowly during the stressed period than that in wild types under the same conditions. Furthermore, transgenic Arabidopsis over-expressing LcVDE showed increased tolerance to drought stress. Copyright © 2014 Elsevier GmbH. All rights reserved.

Tob1 induces apoptosis and inhibits proliferation, migration and invasion of gastric cancer cells by activating Smad4 and inhibiting β‑catenin signaling.

PubMed

Kundu, Juthika; Wahab, S M Riajul; Kundu, Joydeb Kumar; Choi, Yoon-La; Erkin, Ozgur Cem; Lee, Hun Seok; Park, Sang Gyu; Shin, Young Kee

2012-09-01

Transducer of ErbB-2.1 (Tob1), a tumor suppressor protein, is inactivated in a variety of cancers including stomach cancer. However, the role of Tob1 in gastric carcinogenesis remains elusive. The present study aimed to investigate whether Tob1 could inhibit gastric cancer progression in vitro, and to elucidate its underlying molecular mechanisms. We found differential expression of Tob1 in human gastric cancer (MKN28, AGS and MKN1) cells. The overexpression of Tob1 induced apoptosis in MKN28 and AGS cells, which was associated with sub-G1 arrest, activation of caspase-3, induction of Bax, inhibition of Bcl-2 and cleavage of poly (ADP-ribose) polymerase (PARP). In addition, Tob1 inhibited proliferation, migration and invasion, which were reversed in MKN1 and AGS cells transfected with Tob1 siRNA. Overexpression of Tob1 in MKN28 and AGS cells induced the expression of Smad4, leading to the increased expression and the promoter activity of p15, which was diminished by silencing of Tob1 using specific siRNA. Tob1 decreased the phosphorylation of Akt and glycogen synthase kinase-3β (GSK3β) in MKN28 and AGS cells, resulting in the reduced protein expression and the transcriptional activity of β‑catenin, which in turn decreased the expression of cyclin D1, cyclin-dependent kinase-4 (CDK4), urokinase plasminogen activator receptor (uPAR) and peroxisome proliferator and activator receptor-δ (PPARδ). Conversely, silencing of Tob1 induced the phosphorylation of Akt and GSK-3β, and increased the expression of β‑catenin and its target genes. Collectively, our study demonstrates that the overexpression of Tob1 inhibits gastric cancer progression by activating Smad4- and inhibiting β‑catenin-mediated signaling pathways.

The roles of call wall invertase inhibitor in regulating chilling tolerance in tomato.

PubMed

Xu, Xiao-Xia; Hu, Qin; Yang, Wan-Nian; Jin, Ye

2017-11-09

Hexoses are important metabolic signals that respond to abiotic and biotic stresses. Cold stress adversely affects plant growth and development, limiting productivity. The mechanism by which sugars regulate plant cold tolerance remains elusive. We examined the function of INVINH1, a cell wall invertase inhibitor, in tomato chilling tolerance. Cold stress suppressed the transcription of INVINH1 and increased that of cell wall invertase genes, Lin6 and Lin8 in tomato seedlings. Silencing INVINH1 expression in tomato increased cell wall invertase activity and enhanced chilling tolerance. Conversely, transgenic tomatoes over-expressing INVINH1 showed reduced cell wall invertase activity and were more sensitive to cold stress. Chilling stress increased glucose and fructose levels, and the hexoses content increased or decreased by silencing or overexpression INVINH1. Glucose applied in vitro masked the differences in chilling tolerance of tomato caused by the different expressions of INVINH1. The repression of INVINH1 or glucose applied in vitro regulated the expression of C-repeat binding factors (CBFs) genes. Transcript levels of NCED1, which encodes 9-cisepoxycarotenoid dioxygenase (NCED), a key enzyme in the biosynthesis of abscisic acid, were suppressed by INVINH1 after exposure to chilling stress. Meanwhile, application of ABA protected plant from chilling damage caused by the different expression of INVINH1. In tomato, INVINH1 plays an important role in chilling tolerance by adjusting the content of glucose and expression of CBFs.

MicroRNA-30d and microRNA-181a regulate HOXA11 expression in the uterosacral ligaments and are overexpressed in pelvic organ prolapse

PubMed Central

Jeon, Myung Jae; Kim, Eun Jae; Lee, Maria; Kim, Hoguen; Choi, Jong Rak; Chae, Hee Dong; Moon, Yeo Jung; Kim, Sei Kwang; Bai, Sang Wook

2015-01-01

The balanced turnover of collagen is necessary to maintain the mechanical strength of pelvic supportive connective tissues. Homeobox (HOX) A11 is a key transcriptional factor that controls collagen metabolism and homoeostasis in the uterosacral ligaments (USLs), and the deficient HOXA11 signalling may contribute to alterations in the biochemical strength of the USLs, leading to pelvic organ prolapse (POP). However, it is unknown how HOXA11 transcripts are regulated in the USLs. In this study, we found that microRNA (miRNA)-30d and 181a were overexpressed in women with POP, and their expression was inversely correlated with HOXA11 mRNA levels. The overexpression of miR-30d or 181a suppressed HOXA11 mRNA and protein levels in 293T cells, whereas the knockdown of these miRNAs enhanced HOXA11 levels and collagen production. Cotransfection of a luciferase reporter plasmid containing the 3′-untranslated region of HOXA11 with miR-30d or 181a mimic resulted in decreased relative luciferase activity. Conversely, cotransfection with anti-miR-30d or 181a increased luciferase activity. Taken together, these results indicate that both miR-30d and 181a are important posttranscriptional regulators of HOXA11 in the USLs and could be a potential therapeutic target for POP. PMID:25630974

AXIN2 expression predicts prostate cancer recurrence and regulates invasion and tumor growth.

PubMed

Hu, Brian R; Fairey, Adrian S; Madhav, Anisha; Yang, Dongyun; Li, Meng; Groshen, Susan; Stephens, Craig; Kim, Philip H; Virk, Navneet; Wang, Lina; Martin, Sue Ellen; Erho, Nicholas; Davicioni, Elai; Jenkins, Robert B; Den, Robert B; Xu, Tong; Xu, Yucheng; Gill, Inderbir S; Quinn, David I; Goldkorn, Amir

2016-05-01

Treatment of prostate cancer (PCa) may be improved by identifying biological mechanisms of tumor growth that directly impact clinical disease progression. We investigated whether genes associated with a highly tumorigenic, drug resistant, progenitor phenotype impact PCa biology and recurrence. Radical prostatectomy (RP) specimens (±disease recurrence, N = 276) were analyzed by qRT-PCR to quantify expression of genes associated with self-renewal, drug resistance, and tumorigenicity in prior studies. Associations between gene expression and PCa recurrence were confirmed by bootstrap internal validation and by external validation in independent cohorts (total N = 675) and in silico. siRNA knockdown and lentiviral overexpression were used to determine the effect of gene expression on PCa invasion, proliferation, and tumor growth. Four candidate genes were differentially expressed in PCa recurrence. Of these, low AXIN2 expression was internally validated in the discovery cohort. Validation in external cohorts and in silico demonstrated that low AXIN2 was independently associated with more aggressive PCa, biochemical recurrence, and metastasis-free survival after RP. Functionally, siRNA-mediated depletion of AXIN2 significantly increased invasiveness, proliferation, and tumor growth. Conversely, ectopic overexpression of AXIN2 significantly reduced invasiveness, proliferation, and tumor growth. Low AXIN2 expression was associated with PCa recurrence after RP in our test population as well as in external validation cohorts, and its expression levels in PCa cells significantly impacted invasiveness, proliferation, and tumor growth. Given these novel roles, further study of AXIN2 in PCa may yield promising new predictive and therapeutic strategies. © 2016 Wiley Periodicals, Inc.

Amplification of a cytochrome P450 gene is associated with resistance to neonicotinoid insecticides in the aphid Myzus persicae.

PubMed

Puinean, Alin M; Foster, Stephen P; Oliphant, Linda; Denholm, Ian; Field, Linda M; Millar, Neil S; Williamson, Martin S; Bass, Chris

2010-06-24

The aphid Myzus persicae is a globally significant crop pest that has evolved high levels of resistance to almost all classes of insecticide. To date, the neonicotinoids, an economically important class of insecticides that target nicotinic acetylcholine receptors (nAChRs), have remained an effective control measure; however, recent reports of resistance in M. persicae represent a threat to the long-term efficacy of this chemical class. In this study, the mechanisms underlying resistance to the neonicotinoid insecticides were investigated using biological, biochemical, and genomic approaches. Bioassays on a resistant M. persicae clone (5191A) suggested that P450-mediated detoxification plays a primary role in resistance, although additional mechanism(s) may also contribute. Microarray analysis, using an array populated with probes corresponding to all known detoxification genes in M. persicae, revealed constitutive over-expression (22-fold) of a single P450 gene (CYP6CY3); and quantitative PCR showed that the over-expression is due, at least in part, to gene amplification. This is the first report of a P450 gene amplification event associated with insecticide resistance in an agriculturally important insect pest. The microarray analysis also showed over-expression of several gene sequences that encode cuticular proteins (2-16-fold), and artificial feeding assays and in vivo penetration assays using radiolabeled insecticide provided direct evidence of a role for reduced cuticular penetration in neonicotinoid resistance. Conversely, receptor radioligand binding studies and nucleotide sequencing of nAChR subunit genes suggest that target-site changes are unlikely to contribute to resistance to neonicotinoid insecticides in M. persicae.

A novel association between p130Cas and resistance to the chemotherapeutic drug adriamycin in human breast cancer cells.

PubMed

Ta, Huy Q; Thomas, Keena S; Schrecengost, Randy S; Bouton, Amy H

2008-11-01

Resistance to chemotherapy remains a major obstacle for the treatment of breast cancer. Understanding the molecular mechanism(s) of resistance is crucial for the development of new effective therapies to treat this disease. This study examines the putative role of p130(Cas) (Cas) in resistance to the cytotoxic agent Adriamycin. High expression of Cas in primary breast tumors is associated with the failure to respond to the antiestrogen tamoxifen and poor prognosis, highlighting the potential clinical importance of this molecule. Here, we show a novel association between Cas and resistance to Adriamycin. We show that Cas overexpression renders MCF-7 breast cancer cells less sensitive to the growth inhibitory and proapoptotic effects of Adriamycin. The catalytic activity of the nonreceptor tyrosine kinase c-Src, but not the epidermal growth factor receptor, is critical for Cas-mediated protection from Adriamycin-induced death. The phosphorylation of Akt and extracellular signal-regulated kinase 1/2 (ERK1/2) is elevated in Cas-overexpressing cells treated with Adriamycin, whereas expression of the proapoptotic protein Bak is decreased. Conversely, Cas depletion in the more resistant T47D and MDA-MB-231 cell lines increases sensitivity to Adriamycin. Based on these data, we propose that Cas activates growth and survival pathways regulated by c-Src, Akt, and ERK1/2 that lead to the inhibition of mitochondrial-mediated apoptosis in the presence of Adriamycin. Because Cas is frequently expressed at high levels in breast cancers, these findings raise the possibility of resensitizing Cas-overexpressing tumors to chemotherapy through perturbation of Cas signaling pathways.

Tissue transglutaminase regulates focal adhesion kinase/AKT activation by modulating PTEN expression in pancreatic cancer cells.

PubMed

Verma, Amit; Guha, Sushovan; Wang, Huamin; Fok, Jansina Y; Koul, Dimpy; Abbruzzese, James; Mehta, Kapil

2008-04-01

Pancreatic ductal adenocarcinoma (PDAC) progresses rapidly and exhibits profound resistance to treatment. We recently reported that a great majority of PDAC tumors and tumor cell lines express elevated levels of tissue transglutaminase (TG2). Here, we provide first evidence that TG2 expression in PDAC cells results in constitutive activation of focal adhesion kinase/AKT by modulating the expression of the tumor suppressor phosphatase PTEN. Using PDAC cell lines, we determined the effect of TG2 overexpression on PTEN stability and functions. We confirmed the correlation between TG2 expression and PTEN levels in a few (n=51) PDAC tumor samples. We observed that expression of TG2 is inversely correlated with PTEN expression in PDAC cells. Ectopic expression of TG2 inhibited PTEN phosphorylation and promoted its degradation by ubiquitin-proteasomal pathway. Conversely, down-regulation of TG2 by small interfering RNA up-regulated PTEN expression. Clinical relevance of these results was evident in an athymic nude mouse model where down-regulation of endogenous TG2 caused a significant retardation in PDAC xenograft growth. Importantly, the analysis of 51 tumor samples from patients with stage II PDAC revealed that overexpression of TG2 was associated with loss of PTEN expression (P=0.023; odds ratio, 4.1). In multivariate analysis, TG2-mediated loss of PTEN was a prognostic factor for overall survival in patients with stage II pancreatic ductal carcinoma independent of tumor stage/lymph node status and tumor differentiation (P=0.01). TG2 expression in PDAC promotes degradation of PTEN by ubiquitin-proteasomal pathway and results in constitutive activation of focal adhesion kinase/AKT cell survival signaling.

Effects of nicotinamide N-methyltransferase on PANC-1 cells proliferation, metastatic potential and survival under metabolic stress.

PubMed

Yu, Tao; Wang, Yong-Tao; Chen, Pan; Li, Yu-Hua; Chen, Yi-Xin; Zeng, Hang; Yu, Ai-Ming; Huang, Min; Bi, Hui-Chang

2015-01-01

Aberrant expression of Nicotinamide N-methyltransferase (NNMT) has been reported in pancreatic cancer. However, the role of NNMT in pancreatic cancer development remains elusive. Therefore, the present study was to investigate the impact of NNMT on pancreatic cancer cell proliferation, metastatic potential and survival under metabolic stress. Pancreatic cancer cell line PANC-1 was transfected with NNMT expression plasmid or small interfering RNA of NNMT to overexpress or knockdown intracellular NNMT expression, respectively. Rate of cell proliferation was monitored. Transwell migration and matrigel invasion assays were conducted to assess cell migration and invasion capacity. Resistance to glucose deprivation, sensitivity to glycolytic inhibition, mitochondrial inhibtion and resistance to rapamycin were examined to evaluate cell survival under metabolic stress. NNMT silencing markedly reduced cell proliferation, whereas NNMT overexpression promoted cell growth moderately. Knocking down NNMT also significantly suppressed the migration and invasion capacities of PANC-1 cells. Conversely, NNMT upregulation enhanced cell migration and invasion capacities. In addition, NNMT knockdown cells were much less resistant to glucose deprivation and rapamycin as well as glycolytic inhibitor 2-deoxyglucose whereas NNMT-expressing cells showed opposite effects although the effects were not so striking. These data sugguest that NNMT plays an important role in PANC-1 cell proliferation, metastatic potential and survival under metabolic stress. © 2015 S. Karger AG, Basel.

Ibuprofen reverts antifungal resistance on Candida albicans showing overexpression of CDR genes.

PubMed

Ricardo, Elisabete; Costa-de-Oliveira, Sofia; Dias, Ana Silva; Guerra, José; Rodrigues, Acácio Gonçalves; Pina-Vaz, Cidália

2009-06-01

Several mechanisms may be associated with Candida albicans resistance to azoles. Ibuprofen was described as being able to revert resistance related to efflux activity in Candida. The aim of this study was to uncover the molecular base of antifungal resistance in C. albicans clinical strains that could be reverted by ibuprofen. Sixty-two clinical isolates and five control strains of C. albicans were studied: the azole susceptibility phenotype was determined according to the Clinical Laboratory for Standards Institute, M27-A2 protocol and minimal inhibitory concentration values were recalculated with ibuprofen (100 microg mL(-1)); synergistic studies between fluconazole and FK506, a Cdr1p inhibitor, were performed using an agar disk diffusion assay and were compared with ibuprofen results. Gene expression was quantified by real-time PCR, with and without ibuprofen, regarding CDR1, CDR2, MDR1, encoding for efflux pumps, and ERG11, encoding for azole target protein. A correlation between susceptibility phenotype and resistance gene expression profiles was determined. Ibuprofen and FK506 showed a clear synergistic effect when combined with fluconazole. Resistant isolates reverting to susceptible after incubation with ibuprofen showed CDR1 and CDR2 overexpression especially of the latter. Conversely, strains that did not revert displayed a remarkable increase in ERG11 expression along with CDR genes. Ibuprofen did not alter resistance gene expression significantly (P>0.05), probably acting as a Cdrp blocker.

The AP-1 transcription factor Fra1 inhibits follicular B cell differentiation into plasma cells

PubMed Central

Grötsch, Bettina; Brachs, Sebastian; Lang, Christiane; Luther, Julia; Derer, Anja; Schlötzer-Schrehardt, Ursula; Bozec, Aline; Fillatreau, Simon; Berberich, Ingolf; Hobeika, Elias; Reth, Michael; Wagner, Erwin F.; Schett, Georg

2014-01-01

The cornerstone of humoral immunity is the differentiation of B cells into antibody-secreting plasma cells. This process is tightly controlled by a regulatory gene network centered on the transcriptional repressor B lymphocyte–induced maturation protein 1 (Blimp1). Proliferation of activated B cells is required to foster Blimp1 expression but needs to be terminated to avoid overshooting immune reactions. Activator protein 1 (AP-1) transcription factors become quickly up-regulated upon B cell activation. We demonstrate that Fra1, a Fos member of AP-1, enhances activation-induced cell death upon induction in activated B cells. Moreover, mice with B cell–specific deletion of Fra1 show enhanced plasma cell differentiation and exacerbated antibody responses. In contrast, transgenic overexpression of Fra1 blocks plasma cell differentiation and immunoglobulin production, which cannot be rescued by Bcl2. On the molecular level, Fra1 represses Blimp1 expression and interferes with binding of the activating AP-1 member c-Fos to the Blimp1 promoter. Conversely, overexpression of c-Fos in Fra1 transgenic B cells releases Blimp1 repression. As Fra1 lacks transcriptional transactivation domains, we propose that Fra1 inhibits Blimp1 expression and negatively controls plasma cell differentiation through binding to the Blimp1 promoter. In summary, we demonstrate that Fra1 negatively controls plasma cell differentiation by repressing Blimp1 expression. PMID:25288397

P-HYDROXYPHENYLPYRUVATE DIOXYGENASE from Medicago sativa is involved in vitamin E biosynthesis and abscisic acid-mediated seed germination

PubMed Central

Jiang, Jishan; Chen, Zhihong; Ban, Liping; Wu, Yudi; Huang, Jianping; Chu, Jinfang; Fang, Shuang; Wang, Zan; Gao, Hongwen; Wang, Xuemin

2017-01-01

P-HYDROXYPHENYLPYRUVATE DIOXYGENASE (HPPD) is the first committed enzyme involved in the biosynthesis of vitamin E, and is characterized by catalyzing the conversion of p-hydroxyphenyl pyruvate (HPP) to homogentisic acid (HGA). Here, an HPPD gene was cloned from Medicago sativa L. and designated MsHPPD, which was expressed at high levels in alfalfa leaves. PEG 6000 (polyethylene glycol), NaCl, abscisic acid and salicylic acid were shown to significantly induce MsHPPD expression, especially in the cotyledons and root tissues. Overexpression of MsHPPD was found to significantly increase the level of β-tocotrienol and the total vitamin E content in Arabidopsis seeds. Furthermore, these transgenic Arabidopsis seeds exhibited an accelerated germination time, compared with wild-type seeds under normal conditions, as well as under NaCl and ABA treatments. Meanwhile, the expression level of several genes associated with ABA biosynthesis (NCED3, NCED5 and NCED9) and the ABA signaling pathway (RAB18, ABI3 and ABI5) were significantly down-regulated in MsHPPD-overexpressing transgenic lines, as well as the total free ABA content. Taken together, these results demonstrate that MsHPPD functions not only in the vitamin E biosynthetic pathway, but also plays a critical role in seed germination via affecting ABA biosynthesis and signaling. PMID:28084442

Msp40 effector of root-knot nematode manipulates plant immunity to facilitate parasitism.

PubMed

Niu, Junhai; Liu, Pei; Liu, Qian; Chen, Changlong; Guo, Quanxin; Yin, Junmei; Yang, Guangsui; Jian, Heng

2016-01-22

Root-knot nematodes (RKNs) are obligate biotrophic parasites that invade plant roots and engage in prolonged and intimate relationships with their hosts. Nematode secretions, some of which have immunosuppressing activity, play essential roles in successful parasitism; however, their mechanisms of action remain largely unknown. Here, we show that the RKN-specific gene MiMsp40, cloned from Meloidogyne incognita, is expressed exclusively in subventral oesophageal gland cells and is strongly upregulated during early parasitic stages. Arabidopsis plants overexpressing MiMsp40 were more susceptible to nematode infection than were wild type plants. Conversely, the host-derived MiMsp40 RNAi suppressed nematode parasitism and/or reproduction. Moreover, overexpression of MiMsp40 in plants suppressed the deposition of callose and the expression of marker genes for bacterial elicitor elf18-triggered immunity. Transient expression of MiMsp40 prevented Bax-triggered defence-related programmed cell death. Co-agroinfiltration assays indicated that MiMsp40 also suppressed macroscopic cell death triggered by MAPK cascades or by the ETI cognate elicitors R3a/Avr3a. Together, these results demonstrate that MiMsp40 is a novel Meloidogyne-specific effector that is injected into plant cells by early parasitic stages of the nematode and that plays a role in suppressing PTI and/or ETI signals to facilitate RKN parasitism.

Transgenic miR156 switchgrass in the field: growth, recalcitrance and rust susceptibility

DOE PAGES

Baxter, Holly L.; Mazarei, Mitra; Dumitrache, Alexandru; ...

2017-04-24

Sustainable utilization of lignocellulosic perennial grass feedstocks will be enabled by high biomass production and optimized cell wall chemistry for efficient conversion into biofuels. MicroRNAs are regulatory elements that modulate the expression of genes involved in various biological functions in plants, including growth and development. In greenhouse studies, overexpressing a microRNA (miR156) gene in switchgrass had dramatic effects on plant architecture and flowering, which appeared to be driven by transgene expression levels. High expressing lines were extremely dwarfed, whereas low and moderate-expressing lines had higher biomass yields, improved sugar release and delayed flowering. Four lines with moderate or low miR156more » overexpression from the prior greenhouse study were selected for a field experiment to assess the relationship between miR156 expression and biomass production over three years. We also analysed important bioenergy feedstock traits such as flowering, disease resistance, cell wall chemistry and biofuel production. Phenotypes of the transgenic lines were inconsistent between the greenhouse and the field as well as among different field growing seasons. One low expressing transgenic line consistently produced more biomass (25%–56%) than the control across all three seasons, which translated to the production of 30% more biofuel per plant during the final season. The other three transgenic lines produced less biomass than the control by the final season, and the two lines with moderate expression levels also exhibited altered disease susceptibilities. Results of this study emphasize the importance of performing multiyear field studies for plants with altered regulatory transgenes that target plant growth and development.« less

Transgenic miR156 switchgrass in the field: growth, recalcitrance and rust susceptibility

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

Baxter, Holly L.; Mazarei, Mitra; Dumitrache, Alexandru

Sustainable utilization of lignocellulosic perennial grass feedstocks will be enabled by high biomass production and optimized cell wall chemistry for efficient conversion into biofuels. MicroRNAs are regulatory elements that modulate the expression of genes involved in various biological functions in plants, including growth and development. In greenhouse studies, overexpressing a microRNA (miR156) gene in switchgrass had dramatic effects on plant architecture and flowering, which appeared to be driven by transgene expression levels. High expressing lines were extremely dwarfed, whereas low and moderate-expressing lines had higher biomass yields, improved sugar release and delayed flowering. Four lines with moderate or low miR156more » overexpression from the prior greenhouse study were selected for a field experiment to assess the relationship between miR156 expression and biomass production over three years. We also analysed important bioenergy feedstock traits such as flowering, disease resistance, cell wall chemistry and biofuel production. Phenotypes of the transgenic lines were inconsistent between the greenhouse and the field as well as among different field growing seasons. One low expressing transgenic line consistently produced more biomass (25%–56%) than the control across all three seasons, which translated to the production of 30% more biofuel per plant during the final season. The other three transgenic lines produced less biomass than the control by the final season, and the two lines with moderate expression levels also exhibited altered disease susceptibilities. Results of this study emphasize the importance of performing multiyear field studies for plants with altered regulatory transgenes that target plant growth and development.« less

LPS causes pericyte loss and microvascular dysfunction via disruption of Sirt3/angiopoietins/Tie-2 and HIF-2α/Notch3 pathways.

PubMed

Zeng, Heng; He, Xiaochen; Tuo, Qin-Hui; Liao, Duan-Fang; Zhang, Guo-Qiang; Chen, Jian-Xiong

2016-02-12

Recent studies reveal a crucial role of pericyte loss in sepsis-associated microvascular dysfunction. Sirtuin 3 (SIRT3) mediates histone protein post-translational modification related to aging and ischemic disease. This study investigated the involvement of SIRT3 in LPS-induced pericyte loss and microvascular dysfunction. Mice were exposed to LPS, expression of Sirt3, HIF-2α, Notch3 and angiopoietins/Tie-2, pericyte/endothelial (EC) coverage and vascular permeability were assessed. Mice treated with LPS significantly reduced the expression of SIRT3, HIF-2α and Notch3 in the lung. Furthermore, exposure to LPS increased Ang-2 while inhibited Ang-1/Tie-2 expression with a reduced pericyte/EC coverage. Intriguingly, knockout of Sirt3 upregulated Ang-2, but downregulated Tie-2 and HIF-2α/Notch3 expression which resulted in a dramatic reduction of pericyte/EC coverage and exacerbation of LPS-induced vascular leakage. Conversely, overexpression of Sirt3 reduced Ang-2 expression and increased Ang-1/Tie-2 and HIF-2α/Notch3 expression in the LPS treated mice. Overexpression of Sirt3 further prevented LPS-induced pericyte loss and vascular leakage. This was accompanied by a significant reduction of the mortality rate. Specific knockout of prolyl hydroxylase-2 (PHD2) increased HIF-2α/Notch3 expression, improved pericyte/EC coverage and reduced the mortality rate in the LPS-treated mice. Our study demonstrates the importance of SIRT3 in preserving vascular integrity by targeting pericytes in the setting of LPS-induced sepsis.

ALD5, PAD1, ATF1 and ATF2 facilitate the catabolism of coniferyl aldehyde, ferulic acid and p-coumaric acid in Saccharomyces cerevisiae

PubMed Central

Adeboye, Peter Temitope; Bettiga, Maurizio; Olsson, Lisbeth

2017-01-01

The ability of Saccharomyces cerevisiae to catabolize phenolic compounds remains to be fully elucidated. Conversion of coniferyl aldehyde, ferulic acid and p-coumaric acid by S. cerevisiae under aerobic conditions was previously reported. A conversion pathway was also proposed. In the present study, possible enzymes involved in the reported conversion were investigated. Aldehyde dehydrogenase Ald5, phenylacrylic acid decarboxylase Pad1, and alcohol acetyltransferases Atf1 and Atf2, were hypothesised to be involved. Corresponding genes for the four enzymes were overexpressed in a S. cerevisiae strain named APT_1. The ability of APT_1 to tolerate and convert the three phenolic compounds was tested. APT_1 was also compared to strains B_CALD heterologously expressing coniferyl aldehyde dehydrogenase from Pseudomonas, and an ald5Δ strain, all previously reported. APT_1 exhibited the fastest conversion of coniferyl aldehyde, ferulic acid and p-coumaric acid. Using the intermediates and conversion products of each compound, the catabolic route of coniferyl aldehyde, ferulic acid and p-coumaric acid in S. cerevisiae was studied in greater detail. PMID:28205618

The zinc finger E-box-binding homeobox 1 (Zeb1) promotes the conversion of mouse fibroblasts into functional neurons.

PubMed

Yan, Long; Li, Yue; Shi, Zixiao; Lu, Xiaoyin; Ma, Jiao; Hu, Baoyang; Jiao, Jianwei; Wang, Hongmei

2017-08-04

The zinc finger E-box-binding transcription factor Zeb1 plays a pivotal role in the epithelial-mesenchymal transition. Numerous studies have focused on the molecular mechanisms by which Zeb1 contributes to this process. However, the functions of Zeb1 beyond the epithelial-mesenchymal transition remain largely elusive. Using a transdifferentiation system to convert mouse embryonic fibroblasts (MEFs) into functional neurons via the neuronal transcription factors achaete-scute family bHLH (basic helix-loop-helix) transcription factor1 ( Ascl1 ), POU class 3 homeobox 2 (POU3F2/ Brn2 ), and neurogenin 2 (Neurog2, Ngn2 ) (ABN), we found that Zeb1 was up-regulated during the early stages of transdifferentiation. Knocking down Zeb1 dramatically attenuated the transdifferentiation efficiency, whereas Zeb1 overexpression obviously increased the efficiency of transdifferentiation from MEFs to neurons. Interestingly, Zeb1 improved the transdifferentiation efficiency induced by even a single transcription factor ( e.g. Asc1 or Ngn2 ). Zeb1 also rapidly promoted the maturation of induced neuron cells to functional neurons and improved the formation of neuronal patterns and electrophysiological characteristics. Induced neuron cells could form functional synapse in vivo after transplantation. Genome-wide RNA arrays showed that Zeb1 overexpression up-regulated the expression of neuron-specific genes and down-regulated the expression of epithelial-specific genes during conversion. Taken together, our results reveal a new role for Zeb1 in the transdifferentiation of MEFs into neurons. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Cancer/stroma interplay via cyclooxygenase-2 and indoleamine 2,3-dioxygenase promotes breast cancer progression.

PubMed

Chen, Jing-Yi; Li, Chien-Feng; Kuo, Cheng-Chin; Tsai, Kelvin K; Hou, Ming-Feng; Hung, Wen-Chun

2014-07-25

Expression of indoleamine 2,3-dioxygenase (IDO) in primary breast cancer increases tumor growth and metastasis. However, the clinical significance of stromal IDO and the regulation of stromal IDO are unclear. Metabolomics and enzyme-linked immunosorbent assay (ELISA) were used to study the effect of cyclooxygenase-2 (COX-2)-overexpressing breast cancer cells on IDO expression in co-cultured human breast fibroblasts. Biochemical inhibitors and short-hairpin RNA (shRNA) were used to clarify how prostaglandin E2 (PGE2) upregulates IDO expression. Associations of stromal IDO with clinicopathologic parameters were tested in tumor specimens. An orthotopic animal model was used to examine the effect of COX-2 and IDO inhibitors on tumor growth. Kynurenine, the metabolite generated by IDO, increases in the supernatant of fibroblasts co-cultured with COX-2-overexpressing breast cancer cells. PGE2 released by cancer cells upregulates IDO expression in fibroblasts through an EP4/signal transducer and activator of transcription 3 (STAT3)-dependent pathway. Conversely, fibroblast-secreted kynurenine promotes the formation of the E-cadherin/Aryl hydrocarbon receptor (AhR)/S-phase kinase-associated protein 2 (Skp2) complex, resulting in degradation of E-cadherin to increase breast cancer invasiveness. The enhancement of motility of breast cancer cells induced by co-culture with fibroblasts is suppressed by the IDO inhibitor 1-methyl-tryptophan. Pathological analysis demonstrates that upregulation of stromal IDO is a poor prognosis factor and is associated with of COX-2 overexpression. Co-expression of cancer COX-2 and stromal IDO predicts a worse disease-free and metastasis-free survival. Finally, COX-2 and IDO inhibitors inhibit tumor growth in vivo. Integration of metabolomics and molecular and pathological approaches reveals the interplay between cancer and stroma via COX-2, and IDO promotes tumor progression and predicts poor patient survival.

Dmrta1 regulates proneural gene expression downstream of Pax6 in the mammalian telencephalon.

PubMed

Kikkawa, Takako; Obayashi, Takeshi; Takahashi, Masanori; Fukuzaki-Dohi, Urara; Numayama-Tsuruta, Keiko; Osumi, Noriko

2013-08-01

The transcription factor Pax6 balances cell proliferation and neuronal differentiation in the mammalian developing neocortex by regulating the expression of target genes. Using microarray analysis, we observed the down-regulation of Dmrta1 (doublesex and mab-3-related transcription factor-like family A1) in the telencephalon of Pax6 homozygous mutant rats (rSey(2) /rSey(2) ). Dmrta1 expression was restricted to the neural stem/progenitor cells of the dorsal telencephalon. Overexpression of Dmrta1 induced the expression of the proneural gene Neurogenin2 (Neurog2) and conversely repressed Ascl1 (Mash1), a proneural gene expressed in the ventral telencephalon. We found that another Dmrt family molecule, Dmrt3, induced Neurog2 expression in the dorsal telencephalon. Our novel findings suggest that dual regulation of proneural genes mediated by Pax6 and Dmrt family members is crucial for cortical neurogenesis. © 2013 The Authors Genes to Cells © 2013 by the Molecular Biology Society of Japan and Wiley Publishing Asia Pty Ltd.

Increased expression of CYP4Z1 promotes tumor angiogenesis and growth in human breast cancer

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

Yu, Wei; Chai, Hongyan; Li, Ying

2012-10-01

Cytochrome P450 (CYP) 4Z1, a novel CYP4 family member, is over-expressed in human mammary carcinoma and associated with high-grade tumors and poor prognosis. However, the precise role of CYP4Z1 in tumor progression is unknown. Here, we demonstrate that CYP4Z1 overexpression promotes tumor angiogenesis and growth in breast cancer. Stable expression of CYP4Z1 in T47D and BT-474 human breast cancer cells significantly increased mRNA expression and production of vascular endothelial growth factor (VEGF)-A, and decreased mRNA levels and secretion of tissue inhibitor of metalloproteinase-2 (TIMP-2), without affecting cell proliferation and anchorage-independent cell growth in vitro. Notably, the conditioned medium from CYP4Z1-expressingmore » cells enhanced proliferation, migration and tube formation of human umbilical vein endothelial cells, and promoted angiogenesis in the zebrafish embryo and chorioallantoic membrane of the chick embryo. In addition, there were lower levels of myristic acid and lauric acid, and higher contents of 20-hydroxyeicosatetraenoic acid (20-HETE) in CYP4Z1-expressing T47D cells compared with vector control. CYP4Z1 overexpression significantly increased tumor weight and microvessel density by 2.6-fold and 1.9-fold in human tumor xenograft models, respectively. Moreover, CYP4Z1 transfection increased the phosphorylation of ERK1/2 and PI3K/Akt, while PI3K or ERK inhibitors and siRNA silencing reversed CYP4Z1-mediated changes in VEGF-A and TIMP-2 expression. Conversely, HET0016, an inhibitor of the CYP4 family, potently inhibited the tumor-induced angiogenesis with associated changes in the intracellular levels of myristic acid, lauric acid and 20-HETE. Collectively, these data suggest that increased CYP4Z1 expression promotes tumor angiogenesis and growth in breast cancer partly via PI3K/Akt and ERK1/2 activation. -- Highlights: ► CYP4Z1 overexpression promotes human breast cancer growth and angiogenesis. ► The pro-angiogenic effects of CYP4Z1 have been studied in vitro and in vivo. ► CYP4Z1 regulates expression and production of VEGF-A and TIMP-2. ► CYP4Z1-induced angiogenesis is associated with PI3K and ERK1/2 activation. ► CYP4Z1 may be an attractive target for anti-cancer therapy.« less

Transgenic soybean overexpressing GmSAMT1 exhibits resistance to multiple-HG types of soybean cyst nematode Heterodera glycines.

PubMed

Lin, Jingyu; Mazarei, Mitra; Zhao, Nan; Hatcher, Catherine N; Wuddineh, Wegi A; Rudis, Mary; Tschaplinski, Timothy J; Pantalone, Vincent R; Arelli, Prakash R; Hewezi, Tarek; Chen, Feng; Stewart, Charles Neal

2016-11-01

Soybean (Glycine max (L.) Merr.) salicylic acid methyl transferase (GmSAMT1) catalyses the conversion of salicylic acid to methyl salicylate. Prior results showed that when GmSAMT1 was overexpressed in transgenic soybean hairy roots, resistance is conferred against soybean cyst nematode (SCN), Heterodera glycines Ichinohe. In this study, we produced transgenic soybean overexpressing GmSAMT1 and characterized their response to various SCN races. Transgenic plants conferred a significant reduction in the development of SCN HG type 1.2.5.7 (race 2), HG type 0 (race 3) and HG type 2.5.7 (race 5). Among transgenic lines, GmSAMT1 expression in roots was positively associated with SCN resistance. In some transgenic lines, there was a significant decrease in salicylic acid titer relative to control plants. No significant seed yield differences were observed between transgenics and control soybean plants grown in one greenhouse with 22 °C day/night temperature, whereas transgenic soybean had higher yield than controls grown a warmer greenhouse (27 °C day/23 °C night) temperature. In a 1-year field experiment in Knoxville, TN, there was no significant difference in seed yield between the transgenic and nontransgenic soybean under conditions with negligible SCN infection. We hypothesize that GmSAMT1 expression affects salicylic acid biosynthesis, which, in turn, attenuates SCN development, without negative consequences to soybean yield or other morphological traits. Thus, we conclude that GmSAMT1 overexpression confers broad resistance to multiple SCN races, which would be potentially applicable to commercial production. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

GP88 (PC-Cell Derived Growth Factor, progranulin) stimulates proliferation and confers letrozole resistance to aromatase overexpressing breast cancer cells

PubMed Central

2011-01-01

Background Aromatase inhibitors (AI) that inhibit breast cancer cell growth by blocking estrogen synthesis have become the treatment of choice for post-menopausal women with estrogen receptor positive (ER+) breast cancer. However, some patients display de novo or acquired resistance to AI. Interactions between estrogen and growth factor signaling pathways have been identified in estrogen-responsive cells as one possible reason for acquisition of resistance. Our laboratory has characterized an autocrine growth factor overexpressed in invasive ductal carcinoma named PC-Cell Derived Growth Factor (GP88), also known as progranulin. In the present study, we investigated the role GP88 on the acquisition of resistance to letrozole in ER+ breast cancer cells Methods We used two aromatase overexpressing human breast cancer cell lines MCF-7-CA cells and AC1 cells and their letrozole resistant counterparts as study models. Effect of stimulating or inhibiting GP88 expression on proliferation, anchorage-independent growth, survival and letrozole responsiveness was examined. Results GP88 induced cell proliferation and conferred letrozole resistance in a time- and dose-dependent fashion. Conversely, naturally letrozole resistant breast cancer cells displayed a 10-fold increase in GP88 expression when compared to letrozole sensitive cells. GP88 overexpression, or exogenous addition blocked the inhibitory effect of letrozole on proliferation, and stimulated survival and soft agar colony formation. In letrozole resistant cells, silencing GP88 by siRNA inhibited cell proliferation and restored their sensitivity to letrozole. Conclusion Our findings provide information on the role of an alternate growth and survival factor on the acquisition of aromatase inhibitor resistance in ER+ breast cancer. PMID:21658239

FBW7 is associated with prognosis, inhibits malignancies and enhances temozolomide sensitivity in glioblastoma cells.

PubMed

Lin, Jing; Ji, Aihui; Qiu, Guanzhong; Feng, Huaizhi; Li, Jian; Li, Shuo; Zou, Yongxiang; Cui, Yong; Song, Chaoli; He, Hua; Lu, Yicheng

2018-04-01

F-box and WD repeat domain-containing 7 (FBW7) is a SCF-type E3 ubiquitin ligase targeting a multitude of oncoproteins for degradation. Acting as one of the most important tumor suppressors, it is frequently inactivated in various tumors. In this study we aimed to evaluate the relationship of FBW7 with glioma pathology and prognosis, and examine its effect in glioma malignancies and temozolomide (TMZ)-based therapy. Clinical tissues and TCGA database analysis revealed that FBW7 expression was correlated inversely with glioma histology and positively with patient survival time. Lentivirus transfection-induced FBW7 overexpression significantly suppressed proliferation, invasion and migration of U251 and U373 cells, whereas knockdown of FBW7 by targeted shRNA promoted proliferation, invasion and migration of glioma cells. Most importantly, the expression level of FBW7 was found to affect the 50% inhibitory concentration (IC50) of U251 and the TMZ-resistant variant. Combining TMZ with FBW7 overexpression notably increased the cytotoxicity compared to TMZ treatment alone, which was conversely attenuated by FBW7 knockdown. Moreover, flow cytometry (FC) analysis showed overexpression of FBW7, TMZ or the combination-increased proportion of G2/M arrest and the apoptotic rate, whereas FBW7 inhibition reduced G2/M arrest and apoptosis in U251 cells. Finally, mechanistic study found that FBW7 overexpression downregulated Aurora B, Mcl1 and Notch1 levels in a time-dependent pattern and this expressional suppression was independent of TMZ. These findings collectively demonstrate the critical role of FBW7 as a prognostic factor and a potential target to overcome chemoresistance of glioblastoma. © 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Hypoxia-Induced Mitogenic Factor Promotes Cardiac Hypertrophy via Calcium-Dependent and Hypoxia-Inducible Factor-1α Mechanisms.

PubMed

Kumar, Santosh; Wang, Gang; Liu, Wenjuan; Ding, Wenwen; Dong, Ming; Zheng, Na; Ye, Hongyu; Liu, Jie

2018-06-11

HIMF (hypoxia-induced mitogenic factor/found in inflammatory zone 1/resistin like α) is a secretory and cytokine-like protein and serves as a critical stimulator of hypoxia-induced pulmonary hypertension. With a role for HIMF in heart disease unknown, we explored the possible roles for HIMF in cardiac hypertrophy by overexpressing and knocking down HIMF in cardiomyocytes and characterizing HIMF gene ( himf ) knockout mice. We found that HIMF mRNA and protein levels were upregulated in phenylephrine-stimulated cardiomyocyte hypertrophy and our mouse model of transverse aortic constriction-induced cardiac hypertrophy, as well as in human hearts with dilated cardiomyopathy. Furthermore, HIMF overexpression could induce cardiomyocyte hypertrophy, as characterized by elevated protein expression of hypertrophic biomarkers (ANP [atrial natriuretic peptide] and β-MHC [myosin heavy chain-β]) and increased cell-surface area compared with controls. Conversely, HIMF knockdown prevented phenylephrine-induced cardiomyocyte hypertrophy and himf ablation in knockout mice significantly attenuated transverse aortic constriction-induced hypertrophic remodeling and cardiac dysfunction. HIMF overexpression increased the cytosolic Ca 2+ concentration and activated the CaN-NFAT (calcineurin-nuclear factor of activated T cell) and MAPK (mitogen-activated protein kinase) pathways; this effect could be prevented by reducing cytosolic Ca 2+ concentration with L-type Ca 2+ channel blocker nifedipine or inhibiting the CaSR (Ca 2+ sensing receptor) with Calhex 231. Furthermore, HIMF overexpression increased HIF-1α (hypoxia-inducible factor) expression in neonatal rat ventricular myocytes, and HIMF knockout inhibited HIF-1α upregulation in transverse aortic constriction mice. Knockdown of HIF-1α attenuated HIMF-induced cardiomyocyte hypertrophy. In conclusion, HIMF has a critical role in the development of cardiac hypertrophy, and targeting HIMF may represent a potential therapeutic strategy. © 2018 American Heart Association, Inc.

CYP3A4-dependent cellular response does not relate to CYP3A4-catalysed metabolites of C-1748 and C-1305 acridine antitumor agents in HepG2 cells.

PubMed

Augustin, Ewa; Niemira, Magdalena; Hołownia, Adam; Mazerska, Zofia

2014-11-01

High CYP3A4 expression sensitizes tumor cells to certain antitumor agents while for others it can lower their therapeutic efficacy. We have elucidated the influence of CYP3A4 overexpression on the cellular response induced by antitumor acridine derivatives, C-1305 and C-1748, in two hepatocellular carcinoma (HepG2) cell lines, Hep3A4 stably transfected with CYP3A4 isoenzyme, and HepC34 expressing empty vector. The compounds were selected considering their different chemical structures and different metabolic pathways seen earlier in human and rat liver microsomes C-1748 was transformed to several metabolites at a higher rate in Hep3A4 than in HepC34 cells. In contrast, C-1305 metabolism in Hep3A4 cells was unchanged compared to HepC34 cells, with each cell line producing a single metabolite of comparable concentration. C-1748 resulted in a progressive appearance of sub-G1 population to its high level in both cell lines. In turn, the sub-G1 fraction was dominated in CYP3A4-overexpressing cells following C-1305 exposure. Both compounds induced necrosis and to a lesser extent apoptosis, which were more pronounced in Hep3A4 than in wild-type cells. In conclusion, CYP3A4-overexpressing cells produce higher levels of C-1748 metabolites, but they do not affect the cellular responses to the drug. Conversely, cellular response was modulated following C-1305 treatment in CYP3A4-overexpressing cells, although metabolism of this drug was unaltered. © 2014 International Federation for Cell Biology.

Oncogenic HER2Δ16 suppresses miR-15a/16 and deregulates BCL-2 to promote endocrine resistance of breast tumors

PubMed Central

Cittelly, Diana M.; Das, Partha M.; Salvo, Virgilio A.; Fonseca, Juan P.; Burow, Matthew E.; Jones, Frank E.

2010-01-01

Tamoxifen is the most commonly prescribed therapy for patients with estrogen receptor (ER)α-positive breast tumors. Tumor resistance to tamoxifen remains a serious clinical problem especially in patients with tumors that also overexpress human epidermal growth factor receptor 2 (HER2). Current preclinical models of HER2 overexpression fail to recapitulate the clinical spectrum of endocrine resistance associated with HER2/ER-positive tumors. Here, we show that ectopic expression of a clinically important oncogenic isoform of HER2, HER2Δ16, which is expressed in >30% of ER-positive breast tumors, promotes tamoxifen resistance and estrogen independence of MCF-7 xenografts. MCF-7/HER2Δ16 cells evade tamoxifen through upregulation of BCL-2, whereas mediated suppression of BCL-2 expression or treatment of MCF-7/HER2Δ16 cells with the BCL-2 family pharmacological inhibitor ABT-737 restores tamoxifen sensitivity. Tamoxifen-resistant MCF-7/HER2Δ16 cells upregulate BCL-2 protein levels in response to suppressed ERα signaling mediated by estrogen withdrawal, tamoxifen treatment or fulvestrant treatment. In addition, HER2Δ16 expression results in suppression of BCL-2-targeting microRNAs miR-15a and miR-16. Reintroduction of miR-15a/16 reduced tamoxifen-induced BCL-2 expression and sensitized MCF-7/HER2Δ16 to tamoxifen. Conversely, inhibition of miR-15a/16 in tamoxifen-sensitive cells activated BCL-2 expression and promoted tamoxifen resistance. Our results suggest that HER2Δ16 expression promotes endocrine-resistant HER2/ERα-positive breast tumors and in contrast to wild-type HER2, preclinical models of HER2Δ16 overexpression recapitulate multiple phenotypes of endocrine-resistant human breast tumors. The mechanism of HER2Δ16 therapeutic evasion, involving tamoxifen-induced upregulation of BCL-2 and suppression of miR-15a/16, provides a template for unique therapeutic interventions combining tamoxifen with modulation of microRNAs and/or ABT-737-mediated BCL-2 inhibition and apoptosis. PMID:20876285

Cucumber (Cucumis sativus L.) Nitric Oxide Synthase Associated Gene1 (CsNOA1) Plays a Role in Chilling Stress

PubMed Central

Liu, Xingwang; Liu, Bin; Xue, Shudan; Cai, Yanlinq; Qi, Wenzhu; Jian, Chen; Xu, Shuo; Wang, Ting; Ren, Huazhong

2016-01-01

Nitric oxide (NO) is a gaseous signaling molecule in plants, transducing information as a result of exposure to low temperatures. However, the underlying molecular mechanism linking NO with chilling stress is not well understood. Here, we functionally characterized the cucumber (Cucumis sativus L.) nitric oxide synthase-associated gene, NITRIC OXIDE ASSOCIATED 1 (CsNOA1). Expression analysis of CsNOA1, using quantitative real-time PCR, in situ hybridization, and a promoter::β-glucuronidase (GUS) reporter assay, revealed that it is expressed mainly in the root and shoot apical meristem (SAM), and that expression is up-regulated by low temperatures. A CsNOA1-GFP fusion protein was found to be localized in the mitochondria, and ectopic expression of CsNOA1 in the A. thaliana noa1 mutant partially rescued the normal phenotype. When overexpressing CsNOA1 in the Atnoa1 mutant under normal condition, no obvious phenotypic differences was observed between its wild type and transgenic plants. However, the leaves from mutant plant grown under chilling conditions showed hydrophanous spots and wilting. Physiology tolerance markers, chlorophyll fluorescence parameter (Fv/Fm), and electrolyte leakage, were observed to dramatically change, compared mutant to overexpressing lines. Transgenic cucumber plants revealed that the gene is required by seedlings to tolerate chilling stress: constitutive over-expression of CsNOA1 led to a greater accumulation of soluble sugars, starch, and an up-regulation of Cold-regulatory C-repeat binding factor3 (CBF3) expression as well as a lower chilling damage index (CI). Conversely, suppression of CsNOA1 expression resulted in the opposite phenotype and a reduced NO content compared to wild type plants. Those results suggest that CsNOA1 regulates cucumber seedlings chilling tolerance. Additionally, under normal condition, we took several classic inhibitors to perform, and detect endogenous NO levels in wild type cucumber seedling. The results suggest that generation of endogenous NO in cucumber leaves occurs largely independently in the (CsNOA1) and nitrate reductase (NR) pathway. PMID:27891134

Wilms' tumorigenesis is altered by misexpression of the transcriptional co-activator, CITED1

PubMed Central

Lovvorn, Harold N.; Boyle, Scott; Shi, Genbin; Shyr, Yu; Wills, Marcia L.; Perantoni, Alan O.; de Caestecker, Mark

2011-01-01

Purpose Wilms' tumors arise from arrested differentiation of renal progenitor cells. CITED1 is a transcriptional regulator that blocks the metanephric mesenchymal-to-epithelial conversion and is expressed in the blastema of both the developing kidney and Wilms' tumors. We hypothesized that alterations of CITED1-dependent signaling promote persistence of blastema and thereby subject these pluripotent cells to future oncogenic events. Methods We used a retroviral delivery system to overexpress the full-length CITED1 (F/L) protein and 2 deletion mutants lacking either of its known functional domains, ΔSID (Smad-4 Interacting Domain) and ΔCR2 (Conserved Region 2; the CITED1 transactivation domain), in a human Wilms' tumor cell line that endogenously expresses CITED1. In vitro effects on cellular proliferation and apoptosis were assayed. In vivo effects on tumorigenesis, growth, proliferation, and apoptosis were determined after heterotransplantation into immunodeficient mice (n = 15 per cell line). Results In vitro, overexpression of CITED1-F/L significantly increased, whereas overexpression of the functionally inactivating mutant, CITED1-ΔCR2, significantly reduced cellular proliferation relative to the other lines ( P <.0001). In vivo, Wilms' tumor incidence was significantly reduced in animals injected with cells overexpressing the mutant CITED1-ΔCR2 (7%) compared with CITED1-F/L (40%, P = .03) and CITED1-ΔSID (60%, P < .002). Similarly, mean tumor volume was least in the CITED1-ΔCR2 animals when compared with CITED1-F/L ( P = .03) and CITED1-ΔSID animals ( P <.005). Furthermore, the CITED1-ΔCR2 tumor showed the least cellular proliferation. Misexpression of CITED1 did not affect apoptosis either in vitro or in vivo. Conclusions Overexpression of CITED1 in a human Wilms' tumor cell line significantly increases proliferation in vitro, whereas mutation of its functionally critical transactivation domain (ΔCR2) significantly reduces proliferation. This mutation further perturbs tumorigenesis and tumor growth after heterotransplantation into immunodeficient mice. We speculate that overexpression of CITED1 promotes expansion of a rapidly proliferating population of blastema and thereby induces an unstable environment highly susceptible to future oncogenic events. PMID:17336183

Amplification of a Cytochrome P450 Gene Is Associated with Resistance to Neonicotinoid Insecticides in the Aphid Myzus persicae

PubMed Central

Puinean, Alin M.; Foster, Stephen P.; Oliphant, Linda; Denholm, Ian; Field, Linda M.; Millar, Neil S.; Williamson, Martin S.; Bass, Chris

2010-01-01

The aphid Myzus persicae is a globally significant crop pest that has evolved high levels of resistance to almost all classes of insecticide. To date, the neonicotinoids, an economically important class of insecticides that target nicotinic acetylcholine receptors (nAChRs), have remained an effective control measure; however, recent reports of resistance in M. persicae represent a threat to the long-term efficacy of this chemical class. In this study, the mechanisms underlying resistance to the neonicotinoid insecticides were investigated using biological, biochemical, and genomic approaches. Bioassays on a resistant M. persicae clone (5191A) suggested that P450-mediated detoxification plays a primary role in resistance, although additional mechanism(s) may also contribute. Microarray analysis, using an array populated with probes corresponding to all known detoxification genes in M. persicae, revealed constitutive over-expression (22-fold) of a single P450 gene (CYP6CY3); and quantitative PCR showed that the over-expression is due, at least in part, to gene amplification. This is the first report of a P450 gene amplification event associated with insecticide resistance in an agriculturally important insect pest. The microarray analysis also showed over-expression of several gene sequences that encode cuticular proteins (2–16-fold), and artificial feeding assays and in vivo penetration assays using radiolabeled insecticide provided direct evidence of a role for reduced cuticular penetration in neonicotinoid resistance. Conversely, receptor radioligand binding studies and nucleotide sequencing of nAChR subunit genes suggest that target-site changes are unlikely to contribute to resistance to neonicotinoid insecticides in M. persicae. PMID:20585623

nlz gene family is required for hindbrain patterning in the zebrafish.

PubMed

Hoyle, Jacqueline; Tang, Yixin P; Wiellette, Elizabeth L; Wardle, Fiona C; Sive, Hazel

2004-04-01

This study describes the conserved nlz gene family whose members encode unusual zinc finger proteins. In the zebrafish neurectoderm, both nlz1 and the newly isolated nlz2 are expressed in the presumptive hindbrain and midbrain/hindbrain boundary, where expression of nlz1 is dependent on pax2a. In addition, nlz2 is uniquely expressed more anteriorly, in the presumptive midbrain and diencephalon. Overexpression of Nlz proteins during gastrula stages inhibits hindbrain development. In particular, ectopically expressed Nlz1 inhibits formation of future rhombomeres 2 and 3 (r2, r3), whereas neighboring r1 and r4 are not affected. Conversely, simultaneous reduction of Nlz1 and Nlz2 protein function by expression of antisense morpholino-modified oligomers leads to expansion of future r3 and r5, with associated loss of r4. These data indicate that one function of the nlz gene family is to specify or maintain r4 identity, and to limit r3 and r5 during hindbrain formation. Copyright 2004 Wiley-Liss, Inc.

Overexpression of AtGRDP2, a novel glycine-rich domain protein, accelerates plant growth and improves stress tolerance

PubMed Central

Ortega-Amaro, María A.; Rodríguez-Hernández, Aída A.; Rodríguez-Kessler, Margarita; Hernández-Lucero, Eloísa; Rosales-Mendoza, Sergio; Ibáñez-Salazar, Alejandro; Delgado-Sánchez, Pablo; Jiménez-Bremont, Juan F.

2015-01-01

Proteins with glycine-rich signatures have been reported in a wide variety of organisms including plants, mammalians, fungi, and bacteria. Plant glycine-rich protein genes exhibit developmental and tissue-specific expression patterns. Herein, we present the characterization of the AtGRDP2 gene using Arabidopsis null and knockdown mutants and, Arabidopsis and lettuce over-expression lines. AtGRDP2 encodes a short glycine-rich domain protein, containing a DUF1399 domain and a putative RNA recognition motif (RRM). AtGRDP2 transcript is mainly expressed in Arabidopsis floral organs, and its deregulation in Arabidopsis Atgrdp2 mutants and 35S::AtGRDP2 over-expression lines produces alterations in development. The 35S::AtGRDP2 over-expression lines grow faster than the WT, while the Atgrdp2 mutants have a delay in growth and development. The over-expression lines accumulate higher levels of indole-3-acetic acid and, have alterations in the expression pattern of ARF6, ARF8, and miR167 regulators of floral development and auxin signaling. Under salt stress conditions, 35S::AtGRDP2 over-expression lines displayed higher tolerance and increased expression of stress marker genes. Likewise, transgenic lettuce plants over-expressing the AtGRDP2 gene manifest increased growth rate and early flowering time. Our data reveal an important role for AtGRDP2 in Arabidopsis development and stress response, and suggest a connection between AtGRDP2 and auxin signaling. PMID:25653657

Overexpression of ACC gene from oleaginous yeast Lipomyces starkeyi enhanced the lipid accumulation in Saccharomyces cerevisiae with increased levels of glycerol 3-phosphate substrates.

PubMed

Wang, Jiancai; Xu, Ronghua; Wang, Ruling; Haque, Mohammad Enamul; Liu, Aizhong

2016-06-01

The conversion of acetyl-CoA to malonyl-CoA by acetyl-CoA carboxylase (ACC) is the rate-limiting step in fatty acid biosynthesis. In this study, a gene coding for ACC was isolated and characterized from an oleaginous yeast, Lipomyces starkeyi. Real-time quantitative PCR (qPCR) analysis of L. starkeyi acetyl-CoA carboxylase gene (LsACC1) showed that the expression levels were upregulated with the fast accumulation of lipids. The LsACC1 was co-overexpressed with the glycerol 3-phosphate dehydrogenase gene (GPD1), which regulates lipids biosynthesis by supplying another substrates glycerol 3-phosphate for storage lipid assembly, in the non-oleaginous yeast Saccharomyces cerevisiae. Further, the S. cerevisiae acetyl-CoA carboxylase (ScACC1) was transferred with GPD1 and its function was analyzed in comparison with LsACC1. The results showed that overexpressed LsACC1 and GPD1 resulted in a 63% increase in S. cerevisiae. This study gives new data in understanding of the molecular mechanisms underlying the regulation of fatty acids and lipid biosynthesis in yeasts.

Podocalyxin EBP50 Ezrin Molecular Complex Enhances the Metastatic Potential of Renal Cell Carcinoma Through Recruiting Rac1 Guanine Nucleotide Exchange Factor ARHGEF7

PubMed Central

Hsu, Yung-Ho; Lin, Wei-Ling; Hou, Yi-Ting; Pu, Yeong-Shiau; Shun, Chia-Tung; Chen, Chi-Ling; Wu, Yih-Yiing; Chen, Jen-Yau; Chen, Tso-Hsiao; Jou, Tzuu-Shuh

2010-01-01

Podocalyxin was initially identified in glomerular podocytes to critically maintain the structural and functional integrity of the glomerular ultrafiltrative apparatus. Lately, it has emerged as a malignant marker in tumors arising from a variety of tissue origins. By immunohistochemistry, we identified that 9.6% of renal cell carcinoma patients overexpress this protein. This subset of patients had significantly shorter disease-specific and overall survivals, and, importantly, we established podocalyxin overexpression as an independent prognostic factor for latent distant metastasis with multivariate analysis. Podocalyxin down-regulation by small interfering RNA led to defective migration in model renal tubular cells, which was corrected by re-expression of podocalyxin. The activity of the small GTPase Rac1, a well-characterized modulator of cell migration, was diminished by podocalyxin knock-down. Conversely, podocalyxin overexpression in human embryonic kidney cells up-regulated Rac1 activity, which depended on a complex formed by podocalyxin, ERM-binding phosphoprotein 50, ezrin, and ARHGEF7, a Rac1 activator. Therefore, podocalyxin can serve as a biomarker to identify renal cell carcinoma patients with higher metastatic potential for more aggressive intervention at earlier clinical stages. PMID:20395446

LncRNA CCAT2 promotes tumorigenesis by over-expressed Pokemon in non-small cell lung cancer.

PubMed

Zhao, Zhihong; Wang, Ju; Wang, Shengfa; Chang, Hao; Zhang, Tiewa; Qu, Junfeng

2017-03-01

Non-small cell lung cancer (NSCLC) remains one of the most important death-related diseases, with poor effective diagnosis and less therapeutic biomarkers. LncRNA colon cancer-associated transcript 2 (CCAT2) was identified as an oncogenic lncRNA and over-expressed in many tumor cells. The aims of this study were to detect the correlation between CCAT2 and its regulatory genes and then explore the potential mechanism between them in NSCLC. In this study, qRT-PCR was used to detect CCAT2, Pokemon and p21 expression. Western-blot was used to detect protein levels of Pokemon and p21. CCK-8 assay and Transwell chambers were used to assess cell viability and invasion. CCAT2 and Pokemon were over-expressed in NSCLC tissue and cells. In NSCLC cells, CCAT2 knockdown significantly decreased cell viability and invasion as well as Pokemon expression, but increased the expression of p21; then CCAT2 overexpression revealed an opposite result. In addition, over-expressed Pokemon reversed the results that induced by si-CCAT2, while down-regulation of Pokemon significantly reversed the results that induced by CCAT2 overexpression. The results indicated that CCAT2 promotes tumorigenesis by over-expression of Pokemon, and the potential mechanism might relate to the Pokemon related gene p21. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

High level over-expression of different NCX isoforms in HEK293 cell lines and primary neuronal cultures is protective following oxygen glucose deprivation.

PubMed

Cross, Jane L; Boulos, Sherif; Shepherd, Kate L; Craig, Amanda J; Lee, Sharon; Bakker, Anthony J; Knuckey, Neville W; Meloni, Bruno P

2012-07-01

In this study we have assessed sodium-calcium exchanger (NCX) protein over-expression on cell viability in primary rat cortical neuronal and HEK293 cell cultures when subjected to oxygen-glucose deprivation (OGD). In cortical neuronal cultures, NCX2 and NCX3 over-expression was achieved using adenoviral vectors, and following OGD increased neuronal survival from ≈20% for control vector treated cultures to ≈80% for both NCX isoforms. In addition, we demonstrated that NCX2 and NCX3 over-expression in cortical neuronal cultures enables neurons to maintain intracellular calcium at significantly lower levels than control vector treated cultures when exposed to high (9mM) extracellular calcium challenge. Further assessment of NCX activity during OGD was performed using HEK293 cell lines generated to over-express NCX1, NCX2 or NCX3 isoforms. While it was shown that NCX isoform expression differed considerably in the different HEK293 cell lines, high levels of NCX over-expression was associated with increased resistance to OGD. Taken together, our findings show that high levels of NCX over-expression increases neuronal and HEK293 cell survival following OGD, improves calcium management in neuronal cultures and provides additional support for NCX as a therapeutic target to reduce ischemic brain injury. Copyright © 2012 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

ALG2 regulates glioblastoma cell proliferation, migration and tumorigenicity

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

Zhang, Dunke; Wang, Feng; Pang, Yi

Apoptosis-linked gene-2 (ALG-2), also known as programmed cell death 6 (PDCD6), has recently been reported to be aberrantly expressed in various tumors and required for tumor cell viability. The aim of the present study was to investigate whether ALG-2 plays a crucial role in tumor cell proliferation, migration and tumorigenicity. In this study, we examined the expression of PDCD6 in glioblastoma cell lines and found that ALG-2 was generally expressed in glioblastoma cell lines. We also performed an analysis of an online database and found that high expression of ALG-2 was associated with poor prognosis (p = 0.039). We found that over-expressionmore » of ALG2 in glioblastoma could inhibit cell proliferation and, conversely, that down-regulation of ALG2 could promote cell proliferation. Further studies showed that over-expression of ALG2 inhibited the migration of tumor cells, whereas down-regulation of ALG2 promoted tumor cell migration. Finally, in vitro and in vivo studies showed that over-expression of ALG2 inhibited the tumorigenic ability of tumor cells, while down-regulation of ALG2 promoted tumor cell tumorigenic ability. In conclusion, ALG2 has a tumor suppressive role in glioblastoma and might be a potential target for the treatment of glioblastoma. - Highlights: • Low ALG2 expression is indicative of poor prognosis in glioblastoma patients. • ALG2 is required for cell proliferation in GBM cells. • ALG2 is involved in GBM cell migration. • ALG2 is involved in GBM cell self-renewal and tumorigenesis in vitro and in vivo.« less

Mic60/Mitofilin Overexpression Alters Mitochondrial Dynamics and Attenuates Vulnerability of Dopaminergic Cells to Dopamine and Rotenone

PubMed Central

Van Laar, Victor S.; Berman, Sarah B.; Hastings, Teresa G.

2017-01-01

Mitochondrial dysfunction has been implicated in Parkinson’s disease (PD) neuropathology. Mic60, also known as mitofilin, is a protein of the inner mitochondrial membrane and a key component of the mitochondrial contact site and cristae junction organizing system (MICOS). Mic60 is critical for maintaining mitochondrial membrane structure and function. We previously demonstrated that mitochondrial Mic60 protein is susceptible to both covalent modification and loss in abundance following exposure to dopamine quinone. In this study, we utilized neuronally-differentiated SH-SY5Y and PC12 dopaminergic cell lines to examine the effects of altered Mic60 levels on mitochondrial function and cellular vulnerability in response to PD-relevant stressors. Short hairpin RNA (shRNA)-mediated knockdown of endogenous Mic60 protein in neuronal SH-SY5Y cells significantly potentiated dopamine-induced cell death, which was rescued by co-expressing shRNA-insensitive Mic60. Conversely, in PC12 and SH-SY5Y cells, Mic60 overexpression significantly attenuated both dopamine- and rotenone-induced cell death as compared to controls. Mic60 overexpression in SH-SY5Y cells was also associated with increased mitochondrial respiration, and, following rotenone exposure, increased spare respiratory capacity. Mic60 knockdown cells exhibited suppressed respiration and, following rotenone treatment, decreased spare respiratory capacity. Mic60 overexpression also affected mitochondrial fission/fusion dynamics. PC12 cells overexpressing Mic60 exhibited increased mitochondrial interconnectivity. Further, both PC12 cells and primary rat cortical neurons overexpressing Mic60 displayed suppressed mitochondrial fission and increased mitochondrial length in neurites. These results suggest that altering levels of Mic60 in dopaminergic neuronal cells significantly affects both mitochondrial homeostasis and cellular vulnerability to the PD-relevant stressors dopamine and rotenone, carrying implications for PD pathogenesis. PMID:27001148

A genetic overhaul of Saccharomyces cerevisiae 424A(LNH-ST) to improve xylose fermentation.

PubMed

Bera, Aloke K; Ho, Nancy W Y; Khan, Aftab; Sedlak, Miroslav

2011-05-01

Robust microorganisms are necessary for economical bioethanol production. However, such organisms must be able to effectively ferment both hexose and pentose sugars present in lignocellulosic hydrolysate to ethanol. Wild type Saccharomyces cerevisiae can rapidly ferment hexose, but cannot ferment pentose sugars. Considerable efforts were made to genetically engineer S. cerevisiae to ferment xylose. Our genetically engineered S cerevisiae yeast, 424A(LNH-ST), expresses NADPH/NADH xylose reductase (XR) that prefer NADPH and NAD(+)-dependent xylitol dehydrogenase (XD) from Pichia stipitis, and overexpresses endogenous xylulokinase (XK). This strain is able to ferment glucose and xylose, as well as other hexose sugars, to ethanol. However, the preference for different cofactors by XR and XD might lead to redox imbalance, xylitol excretion, and thus might reduce ethanol yield and productivity. In the present study, genes responsible for the conversion of xylose to xylulose with different cofactor specificity (1) XR from N. crassa (NADPH-dependent) and C. parapsilosis (NADH-dependent), and (2) mutant XD from P. stipitis (containing three mutations D207A/I208R/F209S) were overexpressed in wild type yeast. To increase the NADPH pool, the fungal GAPDH enzyme from Kluyveromyces lactis was overexpressed in the 424A(LNH-ST) strain. Four pentose phosphate pathway (PPP) genes, TKL1, TAL1, RKI1 and RPE1 from S. cerevisiae, were also overexpressed in 424A(LNH-ST). Overexpression of GAPDH lowered xylitol production by more than 40%. However, other strains carrying different combinations of XR and XD, as well as new strains containing the overexpressed PPP genes, did not yield any significant improvement in xylose fermentation.

Wnt/beta-Catenin, Foxa2, and CXCR4 Axis Controls Prostate Cancer Progression

DTIC Science & Technology

2014-07-01

NT1 cells that over-expressing Foxa2. The reason we used NT1 cells for the Foxa2 over-expressing experiments is that NT1 is an AR-expressing... cells . We have also established NT1 cells over-expressing a dominant active beta-catenin. We have characterized these cells . Our research found: 1...expression profiles of control NT1 , NT1 /Foxa2, and NT1 /beta-catenin cells Figure 1. We did RT-PCR to examine the expression of key

An agmatine-inducible system for the expression of recombinant proteins in Enterococcus faecalis.

PubMed

Linares, Daniel M; Perez, Marta; Ladero, Victor; Del Rio, Beatriz; Redruello, Begoña; Martin, M Cruz; Fernandez, María; Alvarez, Miguel A

2014-12-04

Scientific interest in Enterococcus faecalis has increased greatly over recent decades. Some strains are involved in food fermentation and offer health benefits, whereas others are vancomycin-resistant and cause infections that are difficult to treat. The limited availability of vectors able to express cloned genes efficiently in E. faecalis has hindered biotechnological studies on the bacterium's regulatory and pathogenicity-related genes. The agmatine deiminase (AGDI) pathway of E. faecalis, involved in the conversion of agmatine into putrescine, is driven by a response inducer gene aguR. This study describes that the exposure to the induction factor (agmatine) results in the transcription of genes under the control of the aguB promoter, including the aguBDAC operon. A novel E. faecalis expression vector, named pAGEnt, combining the aguR inducer gene and the aguB promoter followed by a cloning site and a stop codon was constructed. pAGEnt was designed for the overexpression and purification of a protein fused to a 10-amino-acid His-tag at the C-terminus. The use of GFP as a reporter of gene expression in E. faecalis revealed that under induction with 60 mM agmatine, fluorescence reached 40 arbitrary units compared to 0 in uninduced cells. pAGEnt vector can be used for the overexpression of recombinant proteins under the induction of agmatine in E. faecalis, with a close correlation between agmatine concentration and fluorescence when GFP was used as reporter.

MicroRNA-320 is Involved in the Regulation of Cardiac Ischemia/Reperfusion Injury by Targeting Hsp20

PubMed Central

Ren, Xiao-Ping; Wang, Xiaohong; Sartor, Maureen A.; Jones, Keith; Qian, Jiang; Nicolaou, Persoulla; Pritchard, Tracy J.; Fan, Guo-Chang

2009-01-01

Background Recent studies have identified critical roles for microRNAs (miRNAs) in a variety of cellular processes, including regulation of cardiomyocyte death. However, the signature of miRNA expression and possible roles of miRNA in the ischemic heart have been less well-studied. Methods and Results Here we performed miRNA arrays to detect the expression pattern of miRNAs in murine hearts subjected to ischemia/reperfusion (I/R) in vivo and ex vivo. Surprisingly, we found that only miR-320 expression was significantly decreased in the hearts upon I/R in vivo and ex vivo. This was further confirmed by Taqman RT-PCR. Gain-of-function and loss-of-function approaches were employed in cultured adult rat cardiomyocytes to investigate the functional roles of miR-320. Overexpression of miR-320 enhanced cardiomyocyte death and apoptosis, while knock-down was cytoprotective, upon simulated I/R. Furthermore, transgenic mice with cardiac-specific overexpression of miR-320 revealed an increased extent of apoptosis and infarction size in the hearts upon I/R in vivo and ex vivo, relative to the WT controls. Conversely, in vivo treatment with antagomir-320 reduced the infarction size, relative to the administration of mutant antagomir-320 and saline controls. Using Target-Scan software and proteomic analysis, we identified Hsp20, a known cardioprotective protein, as an important candidate target for miR-320. This was validated experimentally by utilizing a luciferase/GFP reporter activity assay and examining the expression of Hsp20 upon miR-320 overexpression and knockdown in cardiomyocytes. Conclusions Our data demonstrate that miR-320 is involved in the regulation of I/R-induced cardiac injury and dysfunction via antithetical regulation of Hsp20. Thus, miR-320 may constitute a new therapeutic target for ischemic heart diseases. PMID:19380620

ALDH2 restores exhaustive exercise-induced mitochondrial dysfunction in skeletal muscle

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

Zhang, Qiuping; Zheng, Jianheng; Qiu, Jun

Background: Mitochondrial aldehyde dehydrogenase 2 (ALDH2) is highly expressed in heart and skeletal muscles, and is the major enzyme that metabolizes acetaldehyde and toxic aldehydes. The cardioprotective effects of ALDH2 during cardiac ischemia/reperfusion injury have been recognized. However, less is known about the function of ALDH2 in skeletal muscle. This study was designed to evaluate the effect of ALDH2 on exhaustive exercise-induced skeletal muscle injury. Methods: We created transgenic mice expressing ALDH2 in skeletal muscles. Male wild-type C57/BL6 (WT) and ALDH2 transgenic mice (ALDH2-Tg), 8-weeks old, were challenged with exhaustive exercise for 1 week to induce skeletal muscle injury. Animalsmore » were sacrificed 24 h post-exercise and muscle tissue was excised. Results: ALDH2-Tg mice displayed significantly increased treadmill exercise capacity compared to WT mice. Exhaustive exercise caused an increase in mRNA levels of the muscle atrophy markers, Atrogin-1 and MuRF1, and reduced mitochondrial biogenesis and fusion in WT skeletal muscles; these effects were attenuated in ALDH2-Tg mice. Exhaustive exercise also enhanced mitochondrial autophagy pathway activity, including increased conversion of LC3-I to LC3-II and greater expression of Beclin1 and Bnip3; the effects of which were mitigated by ALDH2 overexpression. In addition, ALDH2-Tg reversed the increase of an oxidative stress biomarker (4-hydroxynonenal) and decreased levels of mitochondrial antioxidant proteins, including manganese superoxide dismutase and NAD(P)H:quinone oxidoreductase 1, in skeletal muscle induced by exhaustive exercise. Conclusion: ALDH2 may reverse skeletal muscle mitochondrial dysfunction due to exhaustive exercise by regulating mitochondria dynamic remodeling and enhancing the quality of mitochondria. - Highlights: • Skeletal muscle ALDH2 expression and activity declines during exhaustive exercise. • ALDH2 overexpression enhances physical performance and restores muscle atrophy. • ALDH2 overexpression attenuates exercise-induced mitochondrial oxidative stress.« less

The miRNA-17∼92 cluster mediates chemoresistance and enhances tumor growth in mantle cell lymphoma via PI3K/AKT pathway activation.

PubMed

Rao, E; Jiang, C; Ji, M; Huang, X; Iqbal, J; Lenz, G; Wright, G; Staudt, L M; Zhao, Y; McKeithan, T W; Chan, W C; Fu, K

2012-05-01

The median survival of patients with mantle cell lymphoma (MCL) ranges from 3 to 5 years with current chemotherapeutic regimens. A common secondary genomic alteration detected in MCL is chromosome 13q31-q32 gain/amplification, which targets a microRNA (miRNA) cluster, miR-17∼92. On the basis of gene expression profiling, we found that high level expression of C13orf25, the primary transcript from which these miRNAs are processed, was associated with poorer survival in patients with MCL (P=0.021). We demonstrated that the protein phosphatase PHLPP2, an important negative regulator of the PI3K/AKT pathway, was a direct target of miR-17∼92 miRNAs, in addition to PTEN and BIM. These proteins were down-modulated in MCL cells with overexpression of the miR-17∼92 cluster. Overexpression of miR-17∼92 activated the PI3K/AKT pathway and inhibited chemotherapy-induced apoptosis in MCL cell lines. Conversely, inhibition of miR-17∼92 expression suppressed the PI3K/AKT pathway and inhibited tumor growth in a xenograft MCL mouse model. Targeting the miR-17∼92 cluster may therefore provide a novel therapeutic approach for patients with MCL.

WIND1 Promotes Shoot Regeneration through Transcriptional Activation of ENHANCER OF SHOOT REGENERATION1 in Arabidopsis[OPEN

PubMed Central

Ohnuma, Mariko; Kurata, Tetsuya; Nakata, Masaru; Ohme-Takagi, Masaru

2017-01-01

Many plant species display remarkable developmental plasticity and regenerate new organs after injury. Local signals produced by wounding are thought to trigger organ regeneration but molecular mechanisms underlying this control remain largely unknown. We previously identified an AP2/ERF transcription factor WOUND INDUCED DEDIFFERENTIATION1 (WIND1) as a central regulator of wound-induced cellular reprogramming in plants. In this study, we demonstrate that WIND1 promotes callus formation and shoot regeneration by upregulating the expression of the ENHANCER OF SHOOT REGENERATION1 (ESR1) gene, which encodes another AP2/ERF transcription factor in Arabidopsis thaliana. The esr1 mutants are defective in callus formation and shoot regeneration; conversely, its overexpression promotes both of these processes, indicating that ESR1 functions as a critical driver of cellular reprogramming. Our data show that WIND1 directly binds the vascular system-specific and wound-responsive cis-element-like motifs within the ESR1 promoter and activates its expression. The expression of ESR1 is strongly reduced in WIND1-SRDX dominant repressors, and ectopic overexpression of ESR1 bypasses defects in callus formation and shoot regeneration in WIND1-SRDX plants, supporting the notion that ESR1 acts downstream of WIND1. Together, our findings uncover a key molecular pathway that links wound signaling to shoot regeneration in plants. PMID:28011694

FLICE-like inhibitory protein (FLIP) protects against apoptosis and suppresses NF-kappaB activation induced by bacterial lipopolysaccharide.

PubMed

Bannerman, Douglas D; Eiting, Kristine T; Winn, Robert K; Harlan, John M

2004-10-01

Bacterial lipopolysaccharide (LPS) via its activation of Toll-like receptor-4 contributes to much of the vascular injury/dysfunction associated with gram-negative sepsis. Inhibition of de novo gene expression has been shown to sensitize endothelial cells (EC) to LPS-induced apoptosis, the onset of which correlates with decreased expression of FLICE-like inhibitory protein (FLIP). We now have data that conclusively establish a role for FLIP in protecting EC against LPS-induced apoptosis. Overexpression of FLIP protected against LPS-induced apoptosis, whereas down-regulation of FLIP using antisense oligonucleotides sensitized EC to direct LPS killing. Interestingly, FLIP overexpression suppressed NF-kappaB activation induced by LPS, but not by phorbol ester, suggesting a specific role for FLIP in mediating LPS activation. Conversely, mouse embryo fibroblasts (MEF) obtained from FLIP -/- mice showed enhanced LPS-induced NF-kappaB activation relative to those obtained from wild-type mice. Reconstitution of FLIP-/- MEF with full-length FLIP reversed the enhanced NF-kappaB activity elicited by LPS in the FLIP -/- cells. Changes in the expression of FLIP had no demonstrable effect on other known LPS/Tlr-4-activated signaling pathways including the p38, Akt, and Jnk pathways. Together, these data support a dual role for FLIP in mediating LPS-induced apoptosis and NF-kappaB activation.

Msp40 effector of root-knot nematode manipulates plant immunity to facilitate parasitism

PubMed Central

Niu, Junhai; Liu, Pei; Liu, Qian; Chen, Changlong; Guo, Quanxin; Yin, Junmei; Yang, Guangsui; Jian, Heng

2016-01-01

Root-knot nematodes (RKNs) are obligate biotrophic parasites that invade plant roots and engage in prolonged and intimate relationships with their hosts. Nematode secretions, some of which have immunosuppressing activity, play essential roles in successful parasitism; however, their mechanisms of action remain largely unknown. Here, we show that the RKN-specific gene MiMsp40, cloned from Meloidogyne incognita, is expressed exclusively in subventral oesophageal gland cells and is strongly upregulated during early parasitic stages. Arabidopsis plants overexpressing MiMsp40 were more susceptible to nematode infection than were wild type plants. Conversely, the host-derived MiMsp40 RNAi suppressed nematode parasitism and/or reproduction. Moreover, overexpression of MiMsp40 in plants suppressed the deposition of callose and the expression of marker genes for bacterial elicitor elf18-triggered immunity. Transient expression of MiMsp40 prevented Bax-triggered defence-related programmed cell death. Co-agroinfiltration assays indicated that MiMsp40 also suppressed macroscopic cell death triggered by MAPK cascades or by the ETI cognate elicitors R3a/Avr3a. Together, these results demonstrate that MiMsp40 is a novel Meloidogyne-specific effector that is injected into plant cells by early parasitic stages of the nematode and that plays a role in suppressing PTI and/or ETI signals to facilitate RKN parasitism. PMID:26797310

FABP4 reversed the regulation of leptin on mitochondrial fatty acid oxidation in mice adipocytes

PubMed Central

Gan, Lu; Liu, Zhenjiang; Cao, Weina; Zhang, Zhenzhen; Sun, Chao

2015-01-01

Fatty acid binding protein 4 (FABP4), plays key role in fatty acid transportation and oxidation, and increases with leptin synergistically during adipose inflammation process. However, the regulation mechanism between FABP4 and leptin on mitochondrial fatty acid oxidation remains unclear. In this study, we found that FABP4 reduced the expression of leptin, CPT-1 and AOX1 in mice adipocytes. Conversely, FABP4 was down-regulated in a time-dependent manner by leptin treatment. Additionally, forced expression of FABP4 attenuated the expression of PGC1-α, UCP2, CPT-1, AOX1 and COX2 compared with leptin incubation. Moreover, mitochondrial membrane potential, fatty acid oxidation enzyme medium-chain acyl-CoA dehydrogenase (MCAD), long-chain acyl-CoA dehydrogenase (LCAD) and Cyt C levels were reduced in response to the overexpression of FABP4. These reductions correspond well with the reduced release of free fatty acid and the inactivation of mitochondrial complexes I and III by FABP4 overexpression. Furthermore, addition of the Akt/mTOR pathway-specific inhibitor (MK2206) blocked the mitochondrial fatty acid oxidation and respiration factors, whereas interference of FABP4 overcame these effects. Taken together, FABP4 could reverse the activation of the leptin-induced mitochondrial fatty acid oxidation, and the inhibition of Akt/mTOR signal pathway played a key role in this process. PMID:26310911

FABP4 reversed the regulation of leptin on mitochondrial fatty acid oxidation in mice adipocytes.

PubMed

Gan, Lu; Liu, Zhenjiang; Cao, Weina; Zhang, Zhenzhen; Sun, Chao

2015-08-27

Fatty acid binding protein 4 (FABP4), plays key role in fatty acid transportation and oxidation, and increases with leptin synergistically during adipose inflammation process. However, the regulation mechanism between FABP4 and leptin on mitochondrial fatty acid oxidation remains unclear. In this study, we found that FABP4 reduced the expression of leptin, CPT-1 and AOX1 in mice adipocytes. Conversely, FABP4 was down-regulated in a time-dependent manner by leptin treatment. Additionally, forced expression of FABP4 attenuated the expression of PGC1-α, UCP2, CPT-1, AOX1 and COX2 compared with leptin incubation. Moreover, mitochondrial membrane potential, fatty acid oxidation enzyme medium-chain acyl-CoA dehydrogenase (MCAD), long-chain acyl-CoA dehydrogenase (LCAD) and Cyt C levels were reduced in response to the overexpression of FABP4. These reductions correspond well with the reduced release of free fatty acid and the inactivation of mitochondrial complexes I and III by FABP4 overexpression. Furthermore, addition of the Akt/mTOR pathway-specific inhibitor (MK2206) blocked the mitochondrial fatty acid oxidation and respiration factors, whereas interference of FABP4 overcame these effects. Taken together, FABP4 could reverse the activation of the leptin-induced mitochondrial fatty acid oxidation, and the inhibition of Akt/mTOR signal pathway played a key role in this process.

Biglycan Overexpression on Tooth Enamel Formation in Transgenic Mice

PubMed Central

Wen, Xin; Zou, YanMing; Luo, Wen; Goldberg, Michel; Moats, Rex; Conti, Peter S.; Snead, Malcolm L.; Paine, Michael L.

2008-01-01

Previously it was shown that the volume of forming enamel of molar teeth in biglycan-null mice was greater than in genetically matched wild-type mice. This phenotypic change appeared to result from an increase in amelogenin expression, implying that biglycan directly influences amelogenin synthesis. To determine whether biglycan over-expression resulted in decreased amelogenin expression, we engineered transgenic mice to over-express biglycan in the enamel organ epithelium. Biglycan over-expression did not significantly affect the amelogenin expression in incisor and molar teeth in 3-day transgenic mice. In the transgenic animals we observed that the immature and mature enamel appeared normal. These results suggested that increasing the biglycan expression, in the cells that synthesize the precursor protein matrix for enamel, has a negligible influence on amelogenesis. PMID:18727043

l-Arabinose Isomerase and d-Xylose Isomerase from Lactobacillus reuteri: Characterization, Coexpression in the Food Grade Host Lactobacillus plantarum, and Application in the Conversion of d-Galactose and d-Glucose

PubMed Central

2014-01-01

The l-arabinose isomerase (l-AI) and the d-xylose isomerase (d-XI) encoding genes from Lactobacillus reuteri (DSMZ 17509) were cloned and overexpressed in Escherichia coli BL21 (DE3). The proteins were purified to homogeneity by one-step affinity chromatography and characterized biochemically. l-AI displayed maximum activity at 65 °C and pH 6.0, whereas d-XI showed maximum activity at 65 °C and pH 5.0. Both enzymes require divalent metal ions. The genes were also ligated into the inducible lactobacillal expression vectors pSIP409 and pSIP609, the latter containing a food grade auxotrophy marker instead of an antibiotic resistance marker, and the l-AI- and d-XI-encoding sequences/genes were coexpressed in the food grade host Lactobacillus plantarum. The recombinant enzymes were tested for applications in carbohydrate conversion reactions of industrial relevance. The purified l-AI converted d-galactose to d-tagatose with a maximum conversion rate of 35%, and the d-XI isomerized d-glucose to d-fructose with a maximum conversion rate of 48% at 60 °C. PMID:24443973

The relationship of thioredoxin-1 and cisplatin resistance: its impact on ROS and oxidative metabolism in lung cancer cells.

PubMed

Wangpaichitr, Medhi; Sullivan, Elizabeth J; Theodoropoulos, George; Wu, Chunjing; You, Min; Feun, Lynn G; Lampidis, Theodore J; Kuo, Macus T; Savaraj, Niramol

2012-03-01

Elimination of cisplatin-resistant lung cancer cells remains a major obstacle. We have shown that cisplatin-resistant tumors have higher reactive oxygen species (ROS) levels and can be exploited for targeted therapy. Here, we show that increased secretion of the antioxidant thioredoxin-1 (TRX1) resulted in lowered intracellular TRX1 and contributed to higher ROS in cisplatin-resistant tumors in vivo and in vitro. By reconstituting TRX1 protein in cisplatin-resistant cells, we increased sensitivity to cisplatin but decreased sensitivity to elesclomol (ROS inducer). Conversely, decreased TRX1 protein in parental cells reduced the sensitivity to cisplatin but increased sensitivity to elesclomol. Cisplatin-resistant cells had increased endogenous oxygen consumption and mitochondrial activity but decreased lactic acid production. They also exhibited higher levels of argininosuccinate synthetase (ASS) and fumarase mRNA, which contributed to oxidative metabolism (OXMET) when compared with parental cells. Restoring intracellular TRX1 protein in cisplatin-resistant cells resulted in lowering ASS and fumarase mRNAs, which in turn sensitized them to arginine deprivation. Interestingly, cisplatin-resistant cells also had significantly higher basal levels of acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS). Overexpressing TRX1 lowered ACC and FAS proteins expressions in cisplatin-resistant cells. Chemical inhibition and short interfering RNA of ACC resulted in significant cell death in cisplatin-resistant compared with parental cells. Conversely, TRX1 overexpressed cisplatin-resistant cells resisted 5-(tetradecyloxy)-2-furoic acid (TOFA)-induced death. Collectively, lowering TRX1 expression through increased secretion leads cisplatin-resistant cells to higher ROS production and increased dependency on OXMET. These changes raise an intriguing therapeutic potential for future therapy in cisplatin-resistant lung cancer.

ATP6AP2 over-expression causes morphological alterations in the hippocampus and in hippocampus-related behaviour.

PubMed

Bracke, A; Schäfer, S; von Bohlen Und Halbach, V; Klempin, F; Bente, K; Bracke, K; Staar, D; van den Brandt, J; Harzsch, S; Bader, M; Wenzel, U O; Peters, J; von Bohlen Und Halbach, O

2018-02-23

The (pro)renin receptor [(P)RR], also known as ATP6AP2 [ATPase 6 accessory protein 2], is highly expressed in the brain. ATP6AP2 plays a role in early brain development, adult hippocampal neurogenesis and in cognitive functions. Lack of ATP6AP2 has deleterious effects, and mutations of ATP6AP2 in humans are associated with, e.g. X-linked intellectual disability. However, little is known about the effects of over-expression of ATP6AP2 in the adult brain. We hypothesized that mice over-expressing ATP6AP2 in the brain might exhibit altered neuroanatomical features and behavioural responses. To this end, we investigated heterozygous transgenic female mice and confirmed increased levels of ATP6AP2 in the brain. Our data show that over-expression of ATP6AP2 does not affect adult hippocampal neurogenesis, exercise-induced cell proliferation, or dendritic spine densities in the hippocampus. Only a reduced ventricular volume on the gross morphological level was found. However, ATP6AP2 over-expressing mice displayed altered exploratory behaviour with respect to the hole-board and novel object recognition tests. Moreover, primary adult hippocampal neural stem cells over-expressing ATP6AP2 exhibit a faster cell cycle progression and increased cell proliferation. Together, in contrast to the known deleterious effects of ATP6AP2 depletion, a moderate over-expression results in moderate behavioural changes and affects cell proliferation rate in vitro.

Shift of microRNA profile upon orthotopic xenografting of glioblastoma spheroid cultures.

PubMed

Halle, Bo; Thomassen, Mads; Venkatesan, Ranga; Kaimal, Vivek; Marcusson, Eric G; Munthe, Sune; Sørensen, Mia D; Aaberg-Jessen, Charlotte; Jensen, Stine S; Meyer, Morten; Kruse, Torben A; Christiansen, Helle; Schmidt, Steffen; Mollenhauer, Jan; Schulz, Mette K; Andersen, Claus; Kristensen, Bjarne W

2016-07-01

Glioblastomas always recur despite surgery, radiotherapy and chemotherapy. A key player in the therapeutic resistance may be immature tumor cells with stem-like properties (TSCs) escaping conventional treatment. A group of promising molecular targets are microRNAs (miRs). miRs are small non-coding RNAs exerting post-transcriptional regulation of gene expression. In this study we aimed to identify over-expressed TSC-related miRs potentially amenable for therapeutic targeting. We used non-differentiated glioblastoma spheroid cultures (GSCs) containing TSCs and compared these to xenografts using a NanoString nCounter platform. This revealed 19 over-expressed miRs in the non-differentiated GSCs. Additionally, non-differentiated GSCs were compared to neural stem cells (NSCs) using a microarray platform. This revealed four significantly over-expressed miRs in the non-differentiated GSCs in comparison to the NSCs. The three most over-expressed miRs in the non-differentiated GSCs compared to xenografts were miR-126, -137 and -128. KEGG pathway analysis suggested the main biological function of these over-expressed miRs to be cell-cycle arrest and diminished proliferation. To functionally validate the profiling results suggesting association of these miRs with stem-like properties, experimental over-expression of miR-128 was performed. A consecutive limiting dilution assay confirmed a significantly elevated spheroid formation in the miR-128 over-expressing cells. This may provide potential therapeutic targets for anti-miRs to identify novel treatment options for GBM patients.

[BCL-2 in primary central nervous system lymphomas. Immunohistochemistry and molecular biology].

PubMed

Buccoliero, A M; Castiglione, F; Caldarella, A; Rossi Degl'Innocenti, D; Taddei, A; Ammannati, F; Mennonna, P; Taddei, G L

2004-10-01

BCL-2 is a membrane protein known to be an apoptosis inhibitor. It is the product of the bcl-2 gene located on chromosome 18. Several different tumors show BCL-2 over-expression as result of a translocation or independently from it. More than 85% of follicular lymphomas and a smaller number of diffuse large cell B lymphomas contain t(14;18) (q32;q21). The aim of this study was to investigate the immunohistochemical expression of the BCL-2 protein and to ascertain, by means of traditional PCR (Polimerase Chain Reaction), its possible dependence from t(14;18) (q32;q21) in 9 primary central nervous system lymphomas. Six cases (67%) shoved immunohistochemical BCL-2 over-expression and 3 cases (33%) had t(14;18). Precisely: 2 cases (22%) had immunohistochemical BCL-2 over-expression and t(14;18) (q32;q21); 4 cases (44%) had BCL-2 over-expression without translocation; 1 case (11%) did not show diffuse BCL-2 over-expression in presence of the traslocation; the remaining 2 cases (22%) did not demonstrate BCL-2 over-expression or t(14;18) (q32;q21). In conclusion, our results indicate primary central nervous system lymphomas frequently show BCL-2 over-expression that in some case may be related to t(14;18) (q32;q21). Nevertheless, t(14;18) (q32;q21), as evaluated by traditional PCR, may not correspond to diffuse immunohistochemical BCL-2 positivity.

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

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

Miao, Zhifeng; Zhao, Tingting; Wang, Zhenning

2012-09-07

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

Ectopic expression of pMADS3 in transgenic petunia phenocopies the petunia blind mutant.

PubMed Central

Tsuchimoto, S; van der Krol, A R; Chua, N H

1993-01-01

We cloned a MADS-box gene, pMADS3, from Petunia hybrida, which shows high sequence homology to the Arabidopsis AGAMOUS and Antirrhinum PLENA. pMADS3 is expressed exclusively in stamens and carpels of wild-type petunia plants. In the petunia mutant blind, which shows homeotic conversions of corolla limbs into antheroid structures with pollen grains and small parts of sepals into carpelloid tissue, pMADS3 is expressed in all floral organs as well as in leaves. Ectopic expression of pMADS3 in transgenic petunia leads to phenocopies of the blind mutant, i.e., the formation of antheroid structures on limbs and carpelloid tissue on sepals. Transgenic tobacco plants that overexpress pMADS3 exhibit an even more severe phenotype, with the sepals forming a carpel-like structure encasing the interior floral organs. Our results identify BLIND as a negative regulator of pMADS3, which specifies stamens and carpels during petunia flower development. PMID:8104573

Down-Regulation of MicroRNA-210 Confers Sensitivity towards 1’S-1’-Acetoxychavicol Acetate (ACA) in Cervical Cancer Cells by Targeting SMAD4

PubMed Central

Phuah, Neoh Hun; Azmi, Mohamad Nurul; Awang, Khalijah; Nagoor, Noor Hasima

2017-01-01

MicroRNAs (miRNAs) are short non-coding RNAs that regulate genes posttranscriptionally. Past studies have reported that miR-210 is up-regulated in many cancers including cervical cancer, and plays a pleiotropic role in carcinogenesis. However, its role in regulating response towards anti-cancer agents has not been fully elucidated. We have previously reported that the natural compound 1’S-1’-acetoxychavicol acetate (ACA) is able to induce cytotoxicity in various cancer cells including cervical cancer cells. Hence, this study aims to investigate the mechanistic role of miR-210 in regulating response towards ACA in cervical cancer cells. In the present study, we found that ACA down-regulated miR-210 expression in cervical cancer cells, and suppression of miR-210 expression enhanced sensitivity towards ACA by inhibiting cell proliferation and promoting apoptosis. Western blot analysis showed increased expression of mothers against decapentaplegic homolog 4 (SMAD4), which was predicted as a target of miR-210 by target prediction programs, following treatment with ACA. Luciferase reporter assay confirmed that miR-210 binds to sequences in 3′UTR of SMAD4. Furthermore, decreased in SMAD4 protein expression was observed when miR-210 was overexpressed. Conversely, SMAD4 protein expression increased when miR-210 expression was suppressed. Lastly, we demonstrated that overexpression of SMAD4 augmented the anti-proliferative and apoptosis-inducing effects of ACA. Taken together, our results demonstrated that down-regulation of miR-210 conferred sensitivity towards ACA in cervical cancer cells by targeting SMAD4. These findings suggest that combination of miRNAs and natural compounds could provide new strategies in treating cervical cancer. PMID:28401751

PPARbeta/delta agonist stimulates human lung carcinoma cell growth through inhibition of PTEN expression: the involvement of PI3K and NF-kappaB signals.

PubMed

Han, ShouWei; Ritzenthaler, Jeffrey D; Zheng, Ying; Roman, Jesse

2008-06-01

Recent studies suggest that activation of peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta) promotes cancer cell survival. We previously demonstrated that a selective PPARbeta/delta agonist, GW501516, stimulated human non-small cell lung carcinoma (NSCLC) cell growth. Here, we explore the mechanisms responsible for this effect. We show that GW501516 decreased phosphate and tensin homolog deleted on chromosome 10 (PTEN), a tumor suppressor known to decrease cell growth and induce apoptosis. Activation of PPARbeta/delta and phosphatidylinositol 3-kinase (PI3K)/Akt signaling was associated with inhibition of PTEN. GW501516 increased NF-kappaB DNA binding activity and p65 protein expression through activation of PPARbeta/delta and PI3K/Akt signals and enhanced the physical interactions between PPARbeta/delta and p65 protein. Conversely, inhibition of PI3K and silencing of p65 by small RNA interference (siRNA) blocked the effect of GW501516 on PTEN expression and on NSCLC cell proliferation. GW501516 also inhibited IKBalpha protein expression. Silencing of IKBalpha enhanced the effect of GW501516 on PTEN protein expression and on cell proliferation. It also augmented the GW501516-induced complex formation of PPARbeta/delta and p65 proteins. Overexpression of PTEN suppressed NSCLC cell growth and eliminated the effect of GW501516 on phosphorylation of Akt. Together, our observations suggest that GW501516 induces the proliferation of NSCLC cells by inhibiting the expression of PTEN through activation of PPARbeta/delta, which stimulates PI3K/Akt and NF-kappaB signaling. Overexpression of PTEN overcomes this effect and unveils PPARbeta/delta and PTEN as potential therapeutic targets in NSCLC.

Overexpression of stromal cell-derived factor 1 and its receptor CXCR4 induces autocrine/paracrine cell proliferation in human pituitary adenomas.

PubMed

Barbieri, Federica; Bajetto, Adriana; Stumm, Ralf; Pattarozzi, Alessandra; Porcile, Carola; Zona, Gianluigi; Dorcaratto, Alessandra; Ravetti, Jean-Louis; Minuto, Francesco; Spaziante, Renato; Schettini, Gennaro; Ferone, Diego; Florio, Tullio

2008-08-15

Hypothalamic or locally produced growth factors and cytokines control pituitary development, functioning, and cell division. We evaluated the expression of the chemokine stromal cell-derived factor 1 (SDF1) and its receptor CXCR4 in human pituitary adenomas and normal pituitary tissues and their role in cell proliferation. The expression of SDF1 and CXCR4 in 65 human pituitary adenomas and 4 human normal pituitaries was determined by reverse transcription-PCR, immunohistochemistry, and confocal immunofluorescence. The proliferative effect of SDF1 was evaluated in eight fibroblast-free human pituitary adenoma cell cultures. CXCR4 mRNA was expressed in 92% of growth hormone (GH)-secreting pituitary adenomas (GHoma) and 81% of nonfunctioning pituitary adenomas (NFPA), whereas SDF1 was identified in 63% and 78% of GHomas and NFPAs, respectively. Immunostaining for CXCR4 and SDF1 showed a strong homogenous labeling in all tumoral cells in both GHomas and NFPAs. In normal tissues, CXCR4 and SDF1 were expressed only in a subset of anterior pituitary cells, with a lower expression of SDF1 compared with its cognate receptor. CXCR4 and SDF1 were not confined to a specific cell population in the anterior pituitary but colocalized with discrete subpopulations of GH-, prolactin-, and adrenocorticorticotropic hormone-secreting cells. Conversely, most of the SDF1-containing cells expressed CXCR4. In six of eight pituitary adenoma primary cultures, SDF1 induced a statistically significant increase in DNA synthesis that was prevented by the treatment with the CXCR4 antagonist AMD3100 or somatostatin. CXCR4 and SDF1 are overexpressed in human pituitary adenomas and CXCR4 activation may contribute to pituitary cell proliferation and, possibly, to adenoma development in humans.

Down-Regulation of MicroRNA-210 Confers Sensitivity towards 1'S-1'-Acetoxychavicol Acetate (ACA) in Cervical Cancer Cells by Targeting SMAD4.

PubMed

Phuah, Neoh Hun; Azmi, Mohamad Nurul; Awang, Khalijah; Nagoor, Noor Hasima

2017-04-01

MicroRNAs (miRNAs) are short non-coding RNAs that regulate genes posttranscriptionally. Past studies have reported that miR-210 is up-regulated in many cancers including cervical cancer, and plays a pleiotropic role in carcinogenesis. However, its role in regulating response towards anti-cancer agents has not been fully elucidated. We have previously reported that the natural compound 1'S-1'-acetoxychavicol acetate (ACA) is able to induce cytotoxicity in various cancer cells including cervical cancer cells. Hence, this study aims to investigate the mechanistic role of miR-210 in regulating response towards ACA in cervical cancer cells. In the present study, we found that ACA down-regulated miR-210 expression in cervical cancer cells, and suppression of miR-210 expression enhanced sensitivity towards ACA by inhibiting cell proliferation and promoting apoptosis. Western blot analysis showed increased expression of mothers against decapentaplegic homolog 4 (SMAD4), which was predicted as a target of miR-210 by target prediction programs, following treatment with ACA. Luciferase reporter assay confirmed that miR-210 binds to sequences in 3'UTR of SMAD4. Furthermore, decreased in SMAD4 protein expression was observed when miR-210 was overexpressed. Conversely, SMAD4 protein expression increased when miR-210 expression was suppressed. Lastly, we demonstrated that overexpression of SMAD4 augmented the anti-proliferative and apoptosis-inducing effects of ACA. Taken together, our results demonstrated that down-regulation of miR-210 conferred sensitivity towards ACA in cervical cancer cells by targeting SMAD4. These findings suggest that combination of miRNAs and natural compounds could provide new strategies in treating cervical cancer.

The cell proliferation antigen Ki-67 organises heterochromatin

PubMed Central

Sobecki, Michal; Mrouj, Karim; Camasses, Alain; Parisis, Nikolaos; Nicolas, Emilien; Llères, David; Gerbe, François; Prieto, Susana; Krasinska, Liliana; David, Alexandre; Eguren, Manuel; Birling, Marie-Christine; Urbach, Serge; Hem, Sonia; Déjardin, Jérôme; Malumbres, Marcos; Jay, Philippe; Dulic, Vjekoslav; Lafontaine, Denis LJ; Feil, Robert; Fisher, Daniel

2016-01-01

Antigen Ki-67 is a nuclear protein expressed in proliferating mammalian cells. It is widely used in cancer histopathology but its functions remain unclear. Here, we show that Ki-67 controls heterochromatin organisation. Altering Ki-67 expression levels did not significantly affect cell proliferation in vivo. Ki-67 mutant mice developed normally and cells lacking Ki-67 proliferated efficiently. Conversely, upregulation of Ki-67 expression in differentiated tissues did not prevent cell cycle arrest. Ki-67 interactors included proteins involved in nucleolar processes and chromatin regulators. Ki-67 depletion disrupted nucleologenesis but did not inhibit pre-rRNA processing. In contrast, it altered gene expression. Ki-67 silencing also had wide-ranging effects on chromatin organisation, disrupting heterochromatin compaction and long-range genomic interactions. Trimethylation of histone H3K9 and H4K20 was relocalised within the nucleus. Finally, overexpression of human or Xenopus Ki-67 induced ectopic heterochromatin formation. Altogether, our results suggest that Ki-67 expression in proliferating cells spatially organises heterochromatin, thereby controlling gene expression. DOI: http://dx.doi.org/10.7554/eLife.13722.001 PMID:26949251

EMMPRIN expression in oral squamous cell carcinomas: correlation with tumor proliferation and patient survival.

PubMed

Monteiro, Luís Silva; Delgado, Maria Leonor; Ricardo, Sara; Garcez, Fernanda; do Amaral, Barbas; Pacheco, José Júlio; Lopes, Carlos; Bousbaa, Hassan

2014-01-01

The aim of our study was to explore the clinicopathological and prognostic significance of extracellular matrix metalloproteinase inducer (EMMPRIN) expression in oral squamous cell carcinomas (OSCC), and its relation with the proliferative tumor status of OSCC. We examined EMMPRIN and Ki-67 proteins expression by immunohistochemistry in 74 cases with OSCC. Statistical analysis was conducted to examine their clinicopathological and prognostic significance in OSCC. EMMPRIN membrane expression was observed in all cases, with both membrane and cytoplasmic tumor expression in 61 cases (82.4%). EMMPRIN overexpression was observed in 56 cases (75.7%). Moderately or poorly differentiated tumors showed EMMPRIN overexpression more frequently than well-differentiated tumors (P = 0.002). Overexpression of EMMPRIN was correlated with high Ki-67 expression (P = 0.004). In the multivariate analysis, EMMPRIN overexpression reveals an adverse independent prognostic value for cancer-specific survival (CSS) (P = 0.034). Our results reveal that EMMPRIN protein is overexpressed in more than two-thirds of OSCC cases, especially in high proliferative and less differentiated tumors. The independent value of EMMPRIN overexpression in CSS suggests that this protein could be used as an important biological prognostic marker for patients with OSCC. Moreover, the high expression of EMMPRIN makes it a possible therapeutic target in OSCC patients.

Overexpression of poplar xylem sucrose synthase in tobacco leads to a thickened cell wall and increased height.

PubMed

Wei, Zhigang; Qu, Zanshuang; Zhang, Lijie; Zhao, Shuanjing; Bi, Zhihong; Ji, Xiaohui; Wang, Xiaowen; Wei, Hairong

2015-01-01

Sucrose synthase (SuSy) is considered the first key enzyme for secondary growth because it is a highly regulated cytosolic enzyme that catalyzes the reversible conversion of sucrose and UDP into UDP-glucose and fructose. Although SuSy enzymes preferentially functions in the direction of sucrose cleavage at most cellular condition, they also catalyze the synthetic reaction. We isolated a gene that encodes a SuSy from Populus simonii×Populus nigra and named it PsnSuSy2 because it shares high similarity to SuSy2 in Populus trichocarpa. RT-PCR revealed that PsnSuSy2 was highly expressed in xylem, but lowly expressed in young leaves. To characterize its functions in secondary growth, multiple tobacco overexpression transgenic lines of PnsSuSy2 were generated via Agrobacterium-mediated transformation. The PsnSuSy2 expression levels and altered wood properties in stem segments from the different transgenic lines were carefully characterized. The results demonstrated that the levels of PsnSuSy2 enzyme activity, chlorophyll content, total soluble sugars, fructose and glucose increased significantly, while the sucrose level decreased significantly. Consequently, the cellulose content and fiber length increased, whereas the lignin content decreased, suggesting that PsnSuSy2 plays a significant role in cleaving sucrose into UDP-glucose and fructose to facilitate cellulose biosynthesis and that promotion of cellulose biosynthesis suppresses lignin biosynthesis. Additionally, the noticeable increase in the lodging resistance in transgenic tobacco stem suggested that the cell wall characteristics were altered by PsnSuSy2 overexpression. Scanning electron microscopy was performed to study the cell wall morphology of stem, and surprisingly, we found that the secondary cell wall was significantly thicker in transgenic tobacco. However, the thickened secondary cell wall did not negatively affect the height of the plants because the PsnSuSy2- overexpressing lines grew taller than the wildtype plants. This systematic analysis demonstrated that PsnSuSy2 plays an important role in cleaving sucrose coupled with cellulose biosynthesis in wood tissue.

α-Lipoic acid reduces neurogenic hypertension by blunting oxidative stress-mediated increase in ADAM17

PubMed Central

de Queiroz, Thyago M.; Xia, Huijing; Filipeanu, Catalin M.; Braga, Valdir A.

2015-01-01

We previously reported that type 2 angiotensin-converting enzyme (ACE2) compensatory activity is impaired by the disintegrin and metalloprotease 17 (ADAM17), and lack of ACE2 is associated with oxidative stress in neurogenic hypertension. To investigate the relationship between ADAM17 and oxidative stress, Neuro2A cells were treated with ANG II (100 nM) 24 h after vehicle or α-lipoic acid (LA, 500 μM). ADAM17 expression was increased by ANG II (120.5 ± 9.1 vs. 100.2 ± 0.8%, P < 0.05) and decreased after LA (69.0 ± 0.3 vs. 120.5 ± 9.1%, P < 0.05). In another set of experiments, LA reduced ADAM17 (92.9 ± 5.3 vs. 100.0 ± 11.2%, P < 0.05) following its overexpression. Moreover, ADAM17 activity was reduced by LA in ADAM17-overexpressing cells [109.5 ± 19.8 vs. 158.0 ± 20.0 fluorescence units (FU)·min−1·μg protein−1, P < 0.05], in which ADAM17 overexpression increased oxidative stress (114.1 ± 2.5 vs. 101.0 ± 1.0%, P < 0.05). Conversely, LA-treated cells attenuated ADAM17 overexpression-induced oxidative stress (76.0 ± 9.1 vs. 114.1 ± 2.5%, P < 0.05). In deoxycorticosterone acetate (DOCA)-salt hypertensive mice, a model in which ADAM17 expression and activity are increased, hypertension was blunted by pretreatment with LA (119.0 ± 2.4 vs. 131.4 ± 2.2 mmHg, P < 0.05). In addition, LA improved dysautonomia and baroreflex sensitivity. Furthermore, LA blunted the increase in NADPH oxidase subunit expression, as well as the increase in ADAM17 and decrease in ACE2 activity in the hypothalamus of DOCA-salt hypertensive mice. Taken together, these data suggest that LA might preserve ACE2 compensatory activity by breaking the feedforward cycle between ADAM17 and oxidative stress, resulting in a reduction of neurogenic hypertension. PMID:26254330

Overexpression of Poplar Xylem Sucrose Synthase in Tobacco Leads to a Thickened Cell Wall and Increased Height

PubMed Central

Wei, Zhigang; Qu, Zanshuang; Zhang, Lijie; Zhao, Shuanjing; Bi, Zhihong; Ji, Xiaohui; Wang, Xiaowen; Wei, Hairong

2015-01-01

Sucrose synthase (SuSy) is considered the first key enzyme for secondary growth because it is a highly regulated cytosolic enzyme that catalyzes the reversible conversion of sucrose and UDP into UDP-glucose and fructose. Although SuSy enzymes preferentially functions in the direction of sucrose cleavage at most cellular condition, they also catalyze the synthetic reaction. We isolated a gene that encodes a SuSy from Populus simonii×Populus nigra and named it PsnSuSy2 because it shares high similarity to SuSy2 in Populus trichocarpa. RT-PCR revealed that PsnSuSy2 was highly expressed in xylem, but lowly expressed in young leaves. To characterize its functions in secondary growth, multiple tobacco overexpression transgenic lines of PnsSuSy2 were generated via Agrobacterium-mediated transformation. The PsnSuSy2 expression levels and altered wood properties in stem segments from the different transgenic lines were carefully characterized. The results demonstrated that the levels of PsnSuSy2 enzyme activity, chlorophyll content, total soluble sugars, fructose and glucose increased significantly, while the sucrose level decreased significantly. Consequently, the cellulose content and fiber length increased, whereas the lignin content decreased, suggesting that PsnSuSy2 plays a significant role in cleaving sucrose into UDP-glucose and fructose to facilitate cellulose biosynthesis and that promotion of cellulose biosynthesis suppresses lignin biosynthesis. Additionally, the noticeable increase in the lodging resistance in transgenic tobacco stem suggested that the cell wall characteristics were altered by PsnSuSy2 overexpression. Scanning electron microscopy was performed to study the cell wall morphology of stem, and surprisingly, we found that the secondary cell wall was significantly thicker in transgenic tobacco. However, the thickened secondary cell wall did not negatively affect the height of the plants because the PsnSuSy2- overexpressing lines grew taller than the wildtype plants. This systematic analysis demonstrated that PsnSuSy2 plays an important role in cleaving sucrose coupled with cellulose biosynthesis in wood tissue. PMID:25807295

Overexpression of K-p21Ras play a prominent role in lung cancer

NASA Astrophysics Data System (ADS)

Zhang, Peng-bo; Zhou, Xin-liang; Yang, Ju-lun

2018-06-01

The proto-oncogene ras product, p21Ras, has been found overexpression in many human tumors. However, the subtypes of overexpressed p21Ras still remain unclear. The purpose of this study was to investigate overexpressed isoforms of p21Ras and their roles in the progress of lung cancer. Method: The expression of total p21Ras in normal lung tissues and lung cancers was determined by immunohistochemically staining with monoclonal antibody (Mab) KGHR-1 which could recognize and broad spectrum reaction with the (K/H/N) ras protein. Then, the isoforms of p21Ras was examined by specific Mab for each p21Ras subtypes. Results: Low expression of total p21Ras was found in 26.67% (8/30) of normal lung tissues, and 81.31% (87/107) of adenocarcinoma harbored overexpressed total p21Ras. Besides, 70.00% (35/50) of squamous cell carcinoma were detected overexpressed total p21Ras. In addition, 122 lung cancer tissues from overexpression of total p21Ras protein were selected to detect the expression of each subtype. And all the 122 lung cancer tissues were K-p21Ras overexpression. Moreover, there was a statistical significance difference between the expression level of total p21Ras and differentiation, and the same results were observed between the expression level of total p21Ras and lymph node metastasis (P<0.05). However, there was no correlation between the expression level of total p21Ras and gender, age, tumor size (P>0.05). Conclusions: Overexpression of K-p21Ras plays a prominent role in the progress of lung cancer and it is suggested that the p21Ras could serve as a promising treatment target in lung cancer.

c-Myc dependent expression of pro-apoptotic Bim renders HER2-overexpressing breast cancer cells dependent on anti-apoptotic Mcl-1.

PubMed

Campone, Mario; Noël, Bélinda; Couriaud, Cécile; Grau, Morgan; Guillemin, Yannis; Gautier, Fabien; Gouraud, Wilfried; Charbonnel, Catherine; Campion, Loïc; Jézéquel, Pascal; Braun, Frédérique; Barré, Benjamin; Coqueret, Olivier; Barillé-Nion, Sophie; Juin, Philippe

2011-09-07

Anti-apoptotic signals induced downstream of HER2 are known to contribute to the resistance to current treatments of breast cancer cells that overexpress this member of the EGFR family. Whether or not some of these signals are also involved in tumor maintenance by counteracting constitutive death signals is much less understood. To address this, we investigated what role anti- and pro-apoptotic Bcl-2 family members, key regulators of cancer cell survival, might play in the viability of HER2 overexpressing breast cancer cells. We used cell lines as an in vitro model of HER2-overexpressing cells in order to evaluate how anti-apoptotic Bcl-2, Bcl-xL and Mcl-1, and pro-apoptotic Puma and Bim impact on their survival, and to investigate how the constitutive expression of these proteins is regulated. Expression of the proteins of interest was confirmed using lysates from HER2-overexpressing tumors and through analysis of publicly available RNA expression data. We show that the depletion of Mcl-1 is sufficient to induce apoptosis in HER2-overexpressing breast cancer cells. This Mcl-1 dependence is due to Bim expression and it directly results from oncogenic signaling, as depletion of the oncoprotein c-Myc, which occupies regions of the Bim promoter as evaluated in ChIP assays, decreases Bim levels and mitigates Mcl-1 dependence. Consistently, a reduction of c-Myc expression by inhibition of mTORC1 activity abrogates occupancy of the Bim promoter by c-Myc, decreases Bim expression and promotes tolerance to Mcl-1 depletion. Western blot analysis confirms that naïve HER2-overexpressing tumors constitutively express detectable levels of Mcl-1 and Bim, while expression data hint on enrichment for Mcl-1 transcripts in these tumors. This work establishes that, in HER2-overexpressing tumors, it is necessary, and maybe sufficient, to therapeutically impact on the Mcl-1/Bim balance for efficient induction of cancer cell death.

Altered AIB1 or AIB1Δ3 Expression Impacts ERα Effects on Mammary Gland Stromal and Epithelial Content

PubMed Central

Nakles, Rebecca E.; Shiffert, Maddalena Tilli; Díaz-Cruz, Edgar S.; Cabrera, M. Carla; Alotaiby, Maram; Miermont, Anne M.; Riegel, Anna T.

2011-01-01

Amplified in breast cancer 1 (AIB1) (also known as steroid receptor coactivator-3) is a nuclear receptor coactivator enhancing estrogen receptor (ER)α and progesterone receptor (PR)-dependent transcription in breast cancer. The splice variant AIB1Δ3 demonstrates increased ability to promote ERα and PR-dependent transcription. Both are implicated in breast cancer risk and antihormone resistance. Conditional transgenic mice tested the in vivo impact of AIB1Δ3 overexpression compared with AIB1 on histological features of increased breast cancer risk and growth response to estrogen and progesterone in the mammary gland. Combining expression of either AIB1 or AIB1Δ3 with ERα overexpression, we investigated in vivo cooperativity. AIB1 and AIB1Δ3 overexpression equivalently increased the prevalence of hyperplastic alveolar nodules but not ductal hyperplasia or collagen content. When AIB1 or AIB1Δ3 overexpression was combined with ERα, both stromal collagen content and ductal hyperplasia prevalence were significantly increased and adenocarcinomas appeared. Overexpression of AIB1Δ3, especially combined with overexpressed ERα, led to an abnormal response to estrogen and progesterone with significant increases in stromal collagen content and development of a multilayered mammary epithelium. AIB1Δ3 overexpression was associated with a significant increase in PR expression and PR downstream signaling genes. AIB1 overexpression produced less marked growth abnormalities and no significant change in PR expression. In summary, AIB1Δ3 overexpression was more potent than AIB1 overexpression in increasing stromal collagen content, inducing abnormal mammary epithelial growth, altering PR expression levels, and mediating the response to estrogen and progesterone. Combining ERα overexpression with either AIB1 or AIB1Δ3 overexpression augmented abnormal growth responses in both epithelial and stromal compartments. PMID:21292825

Expression of lung resistance protein and correlation with other drug resistance proteins and outcome in myelodysplastic syndromes.

PubMed

Lepelley, P; Poulain, S; Grardel, N; Preudhomme, C; Cosson, A; Fenaux, P

1998-05-01

The major vault lung resistance protein LRP is a cytoplasmic protein involved in drug resistance, especially in acute myeloid leukemia. We looked for LRP overexpression, using immunocytochemistry with LRP 56 monoclonal antibody, on marrow slides from 41 cases of myelodysplastic syndromes (MDS). LRP overexpression (LRP+) was defined by expression of LRP 56 in at least 20% of marrow blasts. LRP overexpression was seen in 19 (46%) cases. Concordant results between LRP overexpression and P-glycoprotein (PGP) expression were seen in 66% of the cases (p = 0.03), and discordant results (LRP+ and PGP-, or LRP- and PGP+) in 33% of the cases. No correlation was seen between LRP overexpression and FAB type, karyotype, CD34, p53 expression and bcl2 overexpression in blasts. Furthermore, in the 18 cases treated with anthracycline-AraC intensive chemotherapy and the 7 cases treated with low dose AraC, the response rate was not significantly different in LRP+ and LRP- patients. Survival was also similar in LRP+ and LRP- patients. In conclusion, LRP overexpression is probably more frequent in MDS than in de novo AML and, as in AML, is only partially correlated with PGP expression. In our experience, however, LRP was not a prognostic factor for response to chemotherapy and survival in MDS.

MITOSTATIN, a putative tumor suppressor on chromosome 12q24.1, is downregulated in human bladder and breast cancer.

PubMed

Vecchione, A; Fassan, M; Anesti, V; Morrione, A; Goldoni, S; Baldassarre, G; Byrne, D; D'Arca, D; Palazzo, J P; Lloyd, J; Scorrano, L; Gomella, L G; Iozzo, R V; Baffa, R

2009-01-15

Allelic deletions on human chromosome 12q24 are frequently reported in a variety of malignant neoplasms, indicating the presence of a tumor suppressor gene(s) in this chromosomal region. However, no reasonable candidate has been identified so far. In this study, we report the cloning and functional characterization of a novel mitochondrial protein with tumor suppressor activity, henceforth designated MITOSTATIN. Human MITOSTATIN was found within a 3.2-kb transcript, which encoded a approximately 62 kDa, ubiquitously expressed protein with little homology to any known protein. We found homozygous deletions and mutations of MITOSTATIN gene in approximately 5 and approximately 11% of various cancer-derived cells and solid tumors, respectively. When transiently overexpressed, MITOSTATIN inhibited colony formation, tumor cell growth and was proapoptotic, all features shared by established tumor suppressor genes. We discovered a specific link between MITOSTATIN overexpression and downregulation of Hsp27. Conversely, MITOSTATIN knockdown cells showed an increase in cell growth and cell survival rates. Finally, MITOSTATIN expression was significantly reduced in primary bladder and breast tumors, and its reduction was associated with advanced tumor stages. Our findings support the hypothesis that MITOSTATIN has many hallmarks of a classical tumor suppressor in solid tumors and may play an important role in cancer development and progression.

Transcriptomic analysis of Saccharomyces cerevisiae upon honokiol treatment.

PubMed

Zhu, Xiaolong; Zou, Shenshen; Li, Youbin; Liang, Yongheng

2017-09-01

Honokiol (HNK), one of the main medicinal components in Magnolia officinalis, possesses antimicrobial activity against a variety of pathogenic bacteria and fungi. However, little is known of the molecular mechanisms underpinning the antimicrobial activity. To explore the molecular mechanism of its antifungal activity, we determined the effects of HNK on the mRNA expression profile of Saccharomyces cerevisiae using a DNA microarray approach. HNK markedly induced the expression of genes related to iron uptake and homeostasis. Conversely, genes associated with respiratory electron transport were downregulated, mirroring the effects of iron starvation. Meanwhile, HNK-induced growth deficiency was partly rescued by iron supplementation and HNK reacted with iron, producing iron complexes that depleted iron. These results suggest that HNK treatment induced iron starvation. Additionally, HNK treatment resulted in the upregulation of genes involved in protein synthesis and drug resistance networks. Furthermore, the deletion of PDR5, a gene encoding the plasma membrane ATP binding cassette (ABC) transporter, conferred sensitivity to HNK. Overexpression of PDR5 enhanced resistance of WT and pdr5Δ strains to HNK. Taken together, these findings suggest that HNK, which can be excluded by overexpression of Pdr5, functions in multiple cellular processes in S. cerevisiae, particularly in inducing iron starvation to inhibit cell growth. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Mice over-expressing BDNF in forebrain neurons develop an altered behavioral phenotype with age.

PubMed

Weidner, Kate L; Buenaventura, Diego F; Chadman, Kathryn K

2014-07-15

Evidence from clinical studies suggests that abnormal activity of brain derived neurotrophic factor (BDNF) contributes to the pathogenesis of autism spectrum disorders (ASDs). A genetically modified line of mice over-expressing a BDNF transgene in forebrain neurons was used to investigate if this mutation leads to changes in behavior consistent with ASD. The mice used in these experiments were behaviorally tested past 5 months of age when spontaneous seizures were evident. These seizures were not observed in age-matched wildtype (WT) mice or younger mice from this transgenic line. The BDNF mice in these experiments weighed less than their WT littermates. The BDNF transgenic (BDNF-tg) mice demonstrated similar levels of sociability in the social approach test. Conversely, the BDNF-tg mice demonstrated less obsessive compulsive-like behavior in the marble burying test, less anxiety-like behavior in the elevated plus maze test, and less depressive-like behavior in the forced swim test. Changes in behavior were found in these older mice that have not been observed in younger mice from this transgenic line, which may be due to the development of seizures as the mice age. These mice do not have an ASD phenotype but may be useful to study adult onset epilepsy. Copyright © 2014 Elsevier B.V. All rights reserved.

Overexpression of Medicago sativa TMT elevates the α-tocopherol content in Arabidopsis seeds, alfalfa leaves, and delays dark-induced leaf senescence.

PubMed

Jiang, Jishan; Jia, Huili; Feng, Guangyan; Wang, Zan; Li, Jun; Gao, Hongwen; Wang, Xuemin

2016-08-01

Alfalfa (Medicago sativa L.) is a major forage legume for livestock and a target for improving their dietary quality. Vitamin E is an essential vitamin that animals must obtain from their diet for proper growth and development. γ-tocopherol methyltransferase (γ-TMT), which catalyzes the conversion of δ- and γ-tocopherols (or tocotrienols) to β- and α-tocopherols (or tocotrienols), respectively, is the final enzyme involved in the vitamin E biosynthetic pathway. The overexpression of M. sativa L.'s γ-TMT (MsTMT) increased the α-tocopherol content 10-15 fold above that of wild type Arabidopsis seeds without altering the total content of vitamin E. Additionally, in response to osmotic stress, the biomass and the expression levels of several osmotic marker genes were significantly higher in the transgenic lines compared with wild type. Overexpression of MsTMT in alfalfa led to a modest, albeit significant, increase in α-tocopherol in leaves and was also responsible for a delayed leaf senescence phenotype. Additionally, the crude protein content was increased, while the acid and neutral detergent fiber contents were unchanged in these transgenic lines. Thus, increased α-tocopherol content occurred in transgenic alfalfa without compromising the nutritional qualities. The targeted metabolic engineering of vitamin E biosynthesis through MsTMT overexpression provides a promising approach to improve the α-tocopherol content of forage crops. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Enhancing biomass and ethanol production by increasing NADPH production in Synechocystis sp. PCC 6803.

PubMed

Choi, Yun-Nam; Park, Jong Moon

2016-08-01

This study demonstrates that increased NADPH production can improve biomass and ethanol production in cyanobacteria. We over-expressed the endogenous zwf gene, which encodes glucose-6-phosphate dehydrogenase of pentose phosphate pathway, in the model cyanobacterium Synechocystis sp. PCC 6803. zwf over-expression resulted in increased NADPH production, and promoted biomass production compared to the wild type in both autotrophic and mixotrophic conditions. Ethanol production pathway including NADPH-dependent alcohol dehydrogenase was also integrated with and without zwf over-expression. Excessive NADPH production by zwf over-expression could improve both biomass and ethanol production in the autotrophic conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

MYC/MIZ1-dependent gene repression inversely coordinates the circadian clock with cell cycle and proliferation.

PubMed

Shostak, Anton; Ruppert, Bianca; Ha, Nati; Bruns, Philipp; Toprak, Umut H; Eils, Roland; Schlesner, Matthias; Diernfellner, Axel; Brunner, Michael

2016-06-24

The circadian clock and the cell cycle are major cellular systems that organize global physiology in temporal fashion. It seems conceivable that the potentially conflicting programs are coordinated. We show here that overexpression of MYC in U2OS cells attenuates the clock and conversely promotes cell proliferation while downregulation of MYC strengthens the clock and reduces proliferation. Inhibition of the circadian clock is crucially dependent on the formation of repressive complexes of MYC with MIZ1 and subsequent downregulation of the core clock genes BMAL1 (ARNTL), CLOCK and NPAS2. We show furthermore that BMAL1 expression levels correlate inversely with MYC levels in 102 human lymphomas. Our data suggest that MYC acts as a master coordinator that inversely modulates the impact of cell cycle and circadian clock on gene expression.

Increased EGFR expression induced by a novel oncogene, CUG2, confers resistance to doxorubicin through Stat1-HDAC4 signaling.

PubMed

Kaowinn, Sirichat; Jun, Seung Won; Kim, Chang Seok; Shin, Dong-Myeong; Hwang, Yoon-Hwae; Kim, Kyujung; Shin, Bosung; Kaewpiboon, Chutima; Jeong, Hyeon Hee; Koh, Sang Seok; Krämer, Oliver H; Johnston, Randal N; Chung, Young-Hwa

2017-12-01

Previously, it has been found that the cancer upregulated gene 2 (CUG2) and the epidermal growth factor receptor (EGFR) both contribute to drug resistance of cancer cells. Here, we explored whether CUG2 may exert its anticancer drug resistance by increasing the expression of EGFR. EGFR expression was assessed using Western blotting, immunofluorescence and capacitance assays in A549 lung cancer and immortalized bronchial BEAS-2B cells, respectively, stably transfected with a CUG2 expression vector (A549-CUG2; BEAS-CUG2) or an empty control vector (A549-Vec; BEAS-Vec). After siRNA-mediated EGFR, Stat1 and HDAC4 silencing, antioxidant and multidrug resistance protein and mRNA levels were assessed using Western blotting and RT-PCR. In addition, the respective cells were treated with doxorubicin after which apoptosis and reactive oxygen species (ROS) levels were measured. Stat1 acetylation was assessed by immunoprecipitation. We found that exogenous CUG2 overexpression induced EGFR upregulation in A549 and BEAS-2B cells, whereas EGFR silencing sensitized these cells to doxorubicin-induced apoptosis. In addition, we found that exogenous CUG2 overexpression reduced the formation of ROS during doxorubicin treatment by enhancing the expression of antioxidant and multidrug resistant proteins such as MnSOD, Foxo1, Foxo4, MRP2 and BCRP, whereas EGFR silencing congruently increased the levels of ROS by decreasing the expression of these proteins. We also found that EGFR silencing and its concomitant Akt, ERK, JNK and p38 MAPK inhibition resulted in a decreased Stat1 phosphorylation and, thus, a decreased activation. Since also acetylation can affect Stat1 activation via a phospho-acetyl switch, HDAC inhibition may sensitize cells to doxorubicin-induced apoptosis. Interestingly, we found that exogenous CUG2 overexpression upregulated HDAC4, but not HDAC2 or HDAC3. Conversely, we found that HDAC4 silencing sensitized the cells to doxorubicin resistance by decreasing Stat1 phosphorylation and EGFR expression, thus indicating an interplay between HDAC4, Stat1 and EGFR. Taken together, we conclude that CUG2-induced EGFR upregulation confers doxorubicin resistance to lung (cancer) cells through Stat1-HDAC4 signaling.

Over-expression of TSPO in the hippocampal CA1 area alleviates cognitive dysfunction caused by lipopolysaccharide in mice.

PubMed

Zhang, Hui; Ma, Li; Yin, Yan-Ling; Dong, Lian-Qiang; Cheng, Gang-Ge; Ma, Ya-Qun; Li, Yun-Feng; Xu, Bai-Nan

2016-09-01

The translocator protein 18kDa (TSPO) is closely related to regulation of immune/inflammatory response. However, the putative role and signaling mechanisms of TSPO in regulation of neuroinflammation remain unclear. GV287 lentiviral vectors mediating TSPO over-expression were injected into bilateral hippocampal CA1 areas to test whether TSPO over-expression was neuroprotective in lipopolysaccharide (LPS)-induced mice model. Finasteride, a blocker of allopregnanolone production, was used to test whether the protective effects were related to steroideogenesis. The results demonstrated that TSPO over-expression increased progesterone and allopregnanolone synthesis. TSPO over-expression in CA1 area improved LPS-induced cognitive deficiency in mice and this cognitive improvement was reversed by finasteride administration. These data suggest that up-regulation of TSPO level during neuroinflammation may be an adaptive response mechanism, a way to provide more neurosteroids. We confer that TSPO could be an attractive drug target for controlling neuroinflammation in the future. Copyright © 2016 Elsevier B.V. All rights reserved.

Involvement of LeMRP, an ATP-binding cassette transporter, in shikonin transport and biosynthesis in Lithospermum erythrorhizon.

PubMed

Zhu, Y; Chu, S-J; Luo, Y-L; Fu, J-Y; Tang, C-Y; Lu, G-H; Pang, Y-J; Wang, X-M; Yang, R-W; Qi, J-L; Yang, Y-H

2018-03-01

Shikonin and its derivatives are important medicinal secondary metabolites accumulating in roots of Lithospermum erythrorhizon. Although some membrane proteins have been identified as transporters of secondary metabolites, the mechanisms underlying shikonin transport and accumulation in L. erythrorhizon cells still remain largely unknown. In this study, we isolated a cDNA encoding LeMRP, an ATP-binding cassette transporter from L. erythrorhizon, and further investigated its functions in the transport and biosynthesis of shikonin using the yeast transformation and transgenic hairy root methods, respectively. Real-time PCR was applied for expression analyses of LeMRP and shikonin biosynthetic enzyme genes. Functional analysis of LeMRP using the heterologous yeast cell expression system showed that LeMRP could be involved in shikonin transport. Transgenic hairy roots of L. erythrorhizon demonstrated that LeMRP overexpressing hairy roots produced more shikonin than the empty vector (EV) control. Real-time PCR results revealed that the enhanced shikonin biosynthesis in the overexpression lines was mainly caused by highly up-regulated expression of genes coding key enzymes (LePAL, HMGR, Le4CL and LePGT) involved in shikonin biosynthesis. Conversely, LeMRP RNAi decreased the accumulation of shikonin and effectively down-regulated expression level of the above genes. Typical inhibitors of ABC proteins, such as azide and buthionine sulphoximine, dramatically inhibited accumulation of shikonin in hairy roots. Our findings provide evidence for the important direct or indirect role of LeMRP in transmembrane transport and biosynthesis of shikonin. © 2017 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

MicroRNA-210 Modulates Endothelial Cell Response to Hypoxia and Inhibits the Receptor Tyrosine Kinase Ligand Ephrin-A3*S⃞

PubMed Central

Fasanaro, Pasquale; D'Alessandra, Yuri; Di Stefano, Valeria; Melchionna, Roberta; Romani, Sveva; Pompilio, Giulio; Capogrossi, Maurizio C.; Martelli, Fabio

2008-01-01

MicroRNAs (miRNAs) are small non-protein-coding RNAs that function as negative gene expression regulators. In the present study, we investigated miRNAs role in endothelial cell response to hypoxia. We found that the expression of miR-210 progressively increased upon exposure to hypoxia. miR-210 overexpression in normoxic endothelial cells stimulated the formation of capillary-like structures on Matrigel and vascular endothelial growth factor-driven cell migration. Conversely, miR-210 blockade via anti-miRNA transfection inhibited the formation of capillary-like structures stimulated by hypoxia and decreased cell migration in response to vascular endothelial growth factor. miR-210 overexpression did not affect endothelial cell growth in both normoxia and hypoxia. However, anti-miR-210 transfection inhibited cell growth and induced apoptosis, in both normoxia and hypoxia. We determined that one relevant target of miR-210 in hypoxia was Ephrin-A3 since miR-210 was necessary and sufficient to down-modulate its expression. Moreover, luciferase reporter assays showed that Ephrin-A3 was a direct target of miR-210. Ephrin-A3 modulation by miR-210 had significant functional consequences; indeed, the expression of an Ephrin-A3 allele that is not targeted by miR-210 prevented miR-210-mediated stimulation of both tubulogenesis and chemotaxis. We conclude that miR-210 up-regulation is a crucial element of endothelial cell response to hypoxia, affecting cell survival, migration, and differentiation. PMID:18417479

Wnt/β-Catenin Regulates the Activity of Epiprofin/Sp6, SHH, FGF, and BMP to Coordinate the Stages of Odontogenesis

PubMed Central

Aurrekoetxea, Maitane; Irastorza, Igor; García-Gallastegui, Patricia; Jiménez-Rojo, Lucia; Nakamura, Takashi; Yamada, Yoshihiko; Ibarretxe, Gaskon; Unda, Fernando J.

2016-01-01

Background: We used an in vitro tooth development model to investigate the effects of overactivation of the Wnt/β-catenin pathway during odontogenesis by bromoindirubin oxime reagent (BIO), a specific inhibitor of GSK-3 activity. Results: Overactivating the Wnt/β-catenin pathway at tooth initiation upregulated and ectopically expressed the epithelial markers Sonic Hedgehog (Shh), Epiprofin (Epfn), and Fibroblast growth factor8 (Fgf8), which are involved in the delimitation of odontogenic fields in the oral ectoderm. This result indicated an ectopic extension of the odontogenic potential. During tooth morphogenesis, Fibroblast growth factor4 (Fgf4), Fibroblast growth factor10 (Fgf10), Muscle segment homeobox 1 (Msx-1), Bone Morphogenetic protein 4 (Bmp4), and Dickkopf WNT signaling pathway inhibitor 1 (Dkk-1) were overexpressed in first molars cultured with BIO. Conversely, the expression levels of Wingless integration site 10b (Wnt-10b) and Shh were reduced. Additionally, the odontoblast differentiation markers Nestin and Epfn showed ectopic overexpression in the dental mesenchyme of BIO-treated molars. Moreover, alkaline phosphatase activity increased in the dental mesenchyme, again suggesting aberrant, ectopic mesenchymal cell differentiation. Finally, Bmp4 downregulated Epfn expression during dental morphogenesis. Conclusions: We suggest the presence of a positive feedback loop wherein Epfn and β-catenin activate each other. The balance of the expression of these two molecules is essential for proper tooth development. We propose a possible link between Wnt, Bmp, and Epfn that would critically determine the correct patterning of dental cusps and the differentiation of odontoblasts and ameloblasts. PMID:27066482

Role of heparanase on hepatic uptake of intestinal derived lipoprotein and fatty streak formation in mice.

PubMed

Planer, David; Metzger, Shulamit; Zcharia, Eyal; Wexler, Isaiah D; Vlodavsky, Israel; Chajek-Shaul, Tova

2011-04-04

Heparanase modulates the level of heparan sulfate proteoglycans (HSPGs) which have an important role in multiple cellular processes. Recent studies indicate that HSPGs have an important function in hepatic lipoprotein handling and processes involving removal of lipoprotein particles. To determine the effects of decreased HSPGs chain length on lipoprotein metabolism and atherosclerosis, transgenic mice over-expressing the human heparanase gene were studied. Hepatic lipid uptake in hpa-Tg mice were evaluated by giving transgenic mice oral fat loads and labeled retinol. Sections of aorta from mice over-expressing heparanase (hpa-Tg) and controls (C57/BL6) fed an atherogenic diet were examined for evidence of atherosclerosis. Heparanase over-expression results in reduced hepatic clearance of postprandial lipoproteins and higher levels of fasting and postprandial serum triglycerides. Heparanase over-expression also induces formation of fatty streaks in the aorta. The mean lesion cross-sectional area in heparanase over-expressing mice was almost 6 times higher when compared to control mice (23,984 µm(2)±5,922 vs. 4,189 µm(2)±1,130, p<0.001). Over-expression of heparanase demonstrates the importance of HSPGs for the uptake of intestinal derived lipoproteins and its role in the formation of fatty streaks.

Role of Heparanase on Hepatic Uptake of Intestinal Derived Lipoprotein and Fatty Streak Formation in Mice

PubMed Central

Planer, David; Metzger, Shulamit; Zcharia, Eyal; Wexler, Isaiah D.; Vlodavsky, Israel; Chajek-Shaul, Tova

2011-01-01

Background Heparanase modulates the level of heparan sulfate proteoglycans (HSPGs) which have an important role in multiple cellular processes. Recent studies indicate that HSPGs have an important function in hepatic lipoprotein handling and processes involving removal of lipoprotein particles. Principal Findings To determine the effects of decreased HSPGs chain length on lipoprotein metabolism and atherosclerosis, transgenic mice over-expressing the human heparanase gene were studied. Hepatic lipid uptake in hpa-Tg mice were evaluated by giving transgenic mice oral fat loads and labeled retinol. Sections of aorta from mice over-expressing heparanase (hpa-Tg) and controls (C57/BL6) fed an atherogenic diet were examined for evidence of atherosclerosis. Heparanase over-expression results in reduced hepatic clearance of postprandial lipoproteins and higher levels of fasting and postprandial serum triglycerides. Heparanase over-expression also induces formation of fatty streaks in the aorta. The mean lesion cross-sectional area in heparanase over-expressing mice was almost 6 times higher when compared to control mice (23,984 µm2±5,922 vs. 4,189 µm2±1,130, p<0.001). Conclusions Over-expression of heparanase demonstrates the importance of HSPGs for the uptake of intestinal derived lipoproteins and its role in the formation of fatty streaks. PMID:21483695

Insulin-like growth factor binding protein 5 suppresses tumor growth and metastasis of human osteosarcoma.

PubMed

Su, Y; Wagner, E R; Luo, Q; Huang, J; Chen, L; He, B-C; Zuo, G-W; Shi, Q; Zhang, B-Q; Zhu, G; Bi, Y; Luo, J; Luo, X; Kim, S H; Shen, J; Rastegar, F; Huang, E; Gao, Y; Gao, J-L; Yang, K; Wietholt, C; Li, M; Qin, J; Haydon, R C; He, T-C; Luu, H H

2011-09-15

Osteosarcoma (OS) is the most common primary malignancy of bone. There is a critical need to identify the events that lead to the poorly understood mechanism of OS development and metastasis. The goal of this investigation is to identify and characterize a novel marker of OS progression. We have established and characterized a highly metastatic OS subline that is derived from the less metastatic human MG63 line through serial passages in nude mice via intratibial injections. Microarray analysis of the parental MG63, the highly metastatic MG63.2 subline, as well as the corresponding primary tumors and pulmonary metastases revealed insulin-like growth factor binding protein 5 (IGFBP5) to be one of the significantly downregulated genes in the metastatic subline. Confirmatory quantitative RT-PCR on 20 genes of interest demonstrated IGFBP5 to be the most differentially expressed and was therefore chosen to be one of the genes for further investigation. Adenoviral mediated overexpression and knockdown of IGFBP5 in the MG63 and MG63.2 cell lines, as well as other OS lines (143B and MNNG/HOS) that are independent of our MG63 lines, were employed to examine the role of IGFBP5. We found that overexpression of IGFBP5 inhibited in vitro cell proliferation, migration and invasion of OS cells. Additionally, IGFBP5 overexpression promoted apoptosis and cell cycle arrest in the G1 phase. In an orthotopic xenograft animal model, overexpression of IGFBP5 inhibited OS tumor growth and pulmonary metastases. Conversely, siRNA-mediated knockdown of IGFBP5 promoted OS tumor growth and pulmonary metastases in vivo. Immunohistochemical staining of patient-matched primary and metastatic OS samples demonstrated decreased IGFBP5 expression in the metastases. These results suggest 1) a role for IGFBP5 as a novel marker that has an important role in the pathogenesis of OS, and 2) that the loss of IGFBP5 function may contribute to more metastatic phenotypes in OS.

AMP-activated Protein Kinase Mediates Apoptosis in Response to Bioenergetic Stress through Activation of the Pro-apoptotic Bcl-2 Homology Domain-3-only Protein BMF*

PubMed Central

Kilbride, Seán M.; Farrelly, Angela M.; Bonner, Caroline; Ward, Manus W.; Nyhan, Kristine C.; Concannon, Caoimhín G.; Wollheim, Claes B.; Byrne, Maria M.; Prehn, Jochen H. M.

2010-01-01

Heterozygous loss-of-function mutations in the hepatocyte nuclear factor 1A (HNF1A) gene result in the pathogenesis of maturity-onset diabetes-of-the-young type 3, (HNF1A-MODY). This disorder is characterized by a primary defect in metabolism-secretion coupling and decreased beta cell mass, attributed to excessive beta cell apoptosis. Here, we investigated the link between energy stress and apoptosis activation following HNF1A inactivation. This study employed single cell fluorescent microscopy, flow cytometry, gene expression analysis, and gene silencing to study the effects of overexpression of dominant-negative (DN)-HNF1A expression on cellular bioenergetics and apoptosis in INS-1 cells. Induction of DN-HNF1A expression led to reduced ATP levels and diminished the bioenergetic response to glucose. This was coupled with activation of the bioenergetic stress sensor AMP-activated protein kinase (AMPK), which preceded the onset of apoptosis. Pharmacological activation of AMPK using aminoimidazole carboxamide ribonucleotide (AICAR) was sufficient to induce apoptosis in naive cells. Conversely, inhibition of AMPK with compound C or AMPKα gene silencing protected against DN-HNF1A-induced apoptosis. Interestingly, AMPK mediated the induction of the pro-apoptotic Bcl-2 homology domain-3-only protein Bmf (Bcl-2-modifying factor). Bmf expression was also elevated in islets of DN-HNF1A transgenic mice. Furthermore, knockdown of Bmf expression in INS-1 cells using siRNA was sufficient to protect against DN-HNF1A-induced apoptosis. Our study suggests that overexpression of DN-HNF1A induces bioenergetic stress and activation of AMPK. This in turn mediates the transcriptional activation of the pro-apoptotic Bcl-2-homology protein BMF, coupling prolonged energy stress to apoptosis activation. PMID:20841353

Identification of novel non-coding RNA-based negative feedback regulating the expression of the oncogenic transcription factor GLI1.

PubMed

Villegas, Victoria E; Rahman, Mohammed Ferdous-Ur; Fernandez-Barrena, Maite G; Diao, Yumei; Liapi, Eleni; Sonkoly, Enikö; Ståhle, Mona; Pivarcsi, Andor; Annaratone, Laura; Sapino, Anna; Ramírez Clavijo, Sandra; Bürglin, Thomas R; Shimokawa, Takashi; Ramachandran, Saraswathi; Kapranov, Philipp; Fernandez-Zapico, Martin E; Zaphiropoulos, Peter G

2014-07-01

Non-coding RNAs are a complex class of nucleic acids, with growing evidence supporting regulatory roles in gene expression. Here we identify a non-coding RNA located head-to-head with the gene encoding the Glioma-associated oncogene 1 (GLI1), a transcriptional effector of multiple cancer-associated signaling pathways. The expression of this three-exon GLI1 antisense (GLI1AS) RNA in cancer cells was concordant with GLI1 levels. siRNAs knockdown of GLI1AS up-regulated GLI1 and increased cellular proliferation and tumor growth in a xenograft model system. Conversely, GLI1AS overexpression decreased the levels of GLI1, its target genes PTCH1 and PTCH2, and cellular proliferation. Additionally, we demonstrate that GLI1 knockdown reduced GLI1AS, while GLI1 overexpression increased GLI1AS, supporting the role of GLI1AS as a target gene of the GLI1 transcription factor. Activation of TGFβ and Hedgehog signaling, two known regulators of GLI1 expression, conferred a concordant up-regulation of GLI1 and GLI1AS in cancer cells. Finally, analysis of the mechanism underlying the interplay between GLI1 and GLI1AS indicates that the non-coding RNA elicits a local alteration of chromatin structure by increasing the silencing mark H3K27me3 and decreasing the recruitment of RNA polymerase II to this locus. Taken together, the data demonstrate the existence of a novel non-coding RNA-based negative feedback loop controlling GLI1 levels, thus expanding the repertoire of mechanisms regulating the expression of this oncogenic transcription factor. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Ski Inhibits TGF-β/phospho-Smad3 Signaling and Accelerates Hypertrophic Differentiation in Chondrocytes

PubMed Central

Kim, Kyung-Ok; Sampson, Erik R.; Maynard, Robert D; O'Keefe, Regis J.; Chen, Di; Drissi, Hicham; Rosier, Randy N.; Hilton, Matthew J.; Zuscik, Michael J.

2012-01-01

Since TGF-β/Smad signaling inhibits chondrocyte maturation, endogenous negative regulators of TGF-β signaling are likely also important regulators of the chondrocyte differentiation process. One such negative regulator, Ski, is an oncoprotein that is known to inhibit TGF-β/Smad3 signaling via its interaction with phospho-Smad3 and recruitment of histone deacetylases (HDACs) to the DNA binding complex. Based on this, we hypothesized that Ski inhibits TGF-β signaling and accelerates maturation in chondrocytes via recruitment of HDACs to transcriptional complexes containing Smads. We tested this hypothesis in chick upper sternal chondrocytes (USCs), where gain and loss of Ski expression experiments were performed. Over-expression of Ski not only reversed the inhibitory effect of TGF-β on the expression of hypertrophic marker genes such as type × collagen (colX) and osteocalcin, it induced these genes basally as well. Conversely, knockdown of Ski by RNA interference led to a reduction of colX and osteocalcin expression under basal conditions. Furthermore, Ski blocked TGF-β induction of cyclinD1 and caused a basal up-regulation of Runx2, consistent with the observed acceleration of hypertrophy. Regarding mechanism, not only does Ski associate with phospho-Smad2 and 3, but its association with phospho-Smad3 is required for recruitment of HDAC4 and 5. Implicating this recruitment of HDACs in the phenotypic effects of Ski in chondrocytes, the HDAC inhibitor SAHA reversed the up-regulation of colX and osteocalcin in Ski over-expressing cells. These results suggest that inhibition of TGF-β signaling by Ski, which involves its association with phospho-Smad3 and recruitment of HDAC4 and 5, leads to accelerated chondrocyte differentiation. PMID:22461172

Gibberellin 20-oxidase gene OsGA20ox3 regulates plant stature and disease development in rice.

PubMed

Qin, Xue; Liu, Jun Hua; Zhao, Wen Sheng; Chen, Xu Jun; Guo, Ze Jian; Peng, You Liang

2013-02-01

Gibberellin (GA) 20-oxidase (GA20ox) catalyses consecutive steps of oxidation in the late part of the GA biosynthetic pathway. A T-DNA insertion mutant (17S-14) in rice, with an elongated phenotype, was isolated. Analysis of the flanking sequences of the T-DNA insertion site revealed that an incomplete T-DNA integration resulted in enhanced constitutively expression of downstream OsGA20ox3 in the mutant. The accumulation of bioactive GA(1) and GA(4) were increased in the mutant in comparison with the wild-type plant. Transgenic plants overexpressing OsGA20ox3 showed phenotypes similar to those of the 17S-14 mutant, and the RNA interference (RNAi) lines that had decreased OsGA20ox3 expression exhibited a semidwarf phenotype. Expression of OsGA20ox3 was detected in the leaves and roots of young seedlings, immature panicles, anthers, and pollens, based on β-glucuronidase (GUS) activity staining in transgenic plants expressing the OsGA20ox3 promoter fused to the GUS gene. The OsGA20ox3 RNAi lines showed enhanced resistance against rice pathogens Magnaporthe oryzae (causing rice blast) and Xanthomonas oryzae pv. oryzae (causing bacterial blight) and increased expression of defense-related genes. Conversely, OsGA20ox3-overexpressing plants were more susceptible to these pathogens comparing with the wild-type plants. The susceptibility of wild-type plants to X. oryzae pv. oryzae was increased by exogenous application of GA(3) and decreased by S-3307 treatment. Together, the results provide direct evidence for a critical role of OsGA20ox3 in regulating not only plant stature but also disease resistance in rice.

The oncogenic role of the In1-ghrelin splicing variant in prostate cancer aggressiveness.

PubMed

Hormaechea-Agulla, Daniel; Gahete, Manuel D; Jiménez-Vacas, Juan M; Gómez-Gómez, Enrique; Ibáñez-Costa, Alejandro; L-López, Fernando; Rivero-Cortés, Esther; Sarmento-Cabral, André; Valero-Rosa, José; Carrasco-Valiente, Julia; Sánchez-Sánchez, Rafael; Ortega-Salas, Rosa; Moreno, María M; Tsomaia, Natia; Swanson, Steve M; Culler, Michael D; Requena, María J; Castaño, Justo P; Luque, Raúl M

2017-08-29

The Ghrelin-system is a complex, pleiotropic family composed of several peptides, including native-ghrelin and its In1-ghrelin splicing variant, and receptors (GHSR 1a/b), which are dysregulated in various endocrine-related tumors, where they associate to pathophysiological features, but the presence, functional role, and mechanisms of actions of In1-ghrelin splicing variant in prostate-cancer (PCa), is completely unexplored. Herein, we aimed to determine the presence of key ghrelin-system components (native-ghrelin, In1-ghrelin, GHSR1a/1b) and their potential pathophysiological role in prostate cancer (PCa). In1-ghrelin and native-ghrelin expression was evaluated by qPCR in prostate tissues from patients with high PCa-risk (n = 52; fresh-tumoral biopsies), and healthy-prostates (n = 12; from cystoprostatectomies) and correlated with clinical parameters using Spearman-test. In addition, In1-ghrelin and native-ghrelin was measured in plasma from an additional cohort of PCa-patients with different risk levels (n = 30) and control-healthy patients (n = 20). In vivo functional (proliferation/migration) and mechanistic (gene expression/signaling-pathways) assays were performed in PCa-cell lines in response to In1-ghrelin and native-ghrelin treatment, overexpression and/or silencing. Finally, tumor progression was monitored in nude-mice injected with PCa-cells overexpressing In1-ghrelin, native-ghrelin and empty vector (control). In1-ghrelin, but not native-ghrelin, was overexpressed in high-risk PCa-samples compared to normal-prostate (NP), and this expression correlated with that of PSA. Conversely, GHSR1a/1b expression was virtually absent. Remarkably, plasmatic In1-ghrelin, but not native-ghrelin, levels were also higher in PCa-patients compared to healthy-controls. Furthermore, In1-ghrelin treatment/overexpression, and to a much lesser extent native-ghrelin, increased aggressiveness features (cell-proliferation, migration and PSA secretion) of NP and PCa cells. Consistently, nude-mice injected with PC-3-cells stably-transfected with In1-ghrelin, but not native-ghrelin, presented larger tumors. These effects were likely mediated by ERK1/2-signaling activation and involved altered expression of key oncogenes/tumor suppressor genes. Finally, In1-ghrelin silencing reduced cell-proliferation and PSA secretion from PCa cells. Altogether, our results indicate that In1-ghrelin levels (in tissue) and circulating levels (in plasma) are increased in PCa where it can regulate key pathophysiological processes, thus suggesting that In1-ghrelin may represent a novel biomarker and a new therapeutic target in PCa.

Improvement of L-valine production at high temperature in Brevibacterium flavum by overexpressing ilvEBNrC genes.

PubMed

Hou, Xiaohu; Ge, Xiangyang; Wu, Di; Qian, He; Zhang, Weiguo

2012-01-01

Brevibacterium flavum ATCC14067 was engineered for L: -valine production by overexpression of different ilv genes; the ilvEBN(r)C genes from B. flavum NV128 provided the best candidate for L: -valine production. In traditional fermentation, L: -valine production reached 30.08 ± 0.92 g/L at 31°C in 72 h with a low conversion efficiency of 0.129 g/g. To further improve the L: -valine production and conversion efficiency based on the optimum temperatures of L: -valine biosynthesis enzymes (above 35°C) and the thermotolerance of B. flavum, the fermentation temperature was increased to 34, 37, and 40°C. As a result, higher metabolic rate and L: -valine biosynthesis enzymes activity were obtained at high temperature, and the maximum L: -valine production, conversion efficiency, and specific L: -valine production rate reached 38.08 ± 1.32 g/L, 0.241 g/g, and 0.133 g g(-1) h(-1), respectively, at 37°C in 48 h fermentation. The strategy for enhancing L: -valine production by overexpression of key enzymes in thermotolerant strains may provide an alternative approach to enhance branched-chain amino acids production with other strains.

Intraventricular Injection of LKB1 Inhibits the Formation of Diet-Induced Obesity in Rats by Activating the AMPK-POMC Neurons-Sympathetic Nervous System Axis.

PubMed

Xi, Pengjiao; Du, Jianying; Liang, Huimin; Han, Jie; Wu, Zhaoxia; Wang, Haomin; He, Lu; Wang, Qiming; Ge, Haize; Li, Yongmei; Xue, Jie; Tian, Derun

2018-01-01

Obesity is increasingly becoming a major public health problem worldwide. Peripheral LKB1 inhibits white fat generation, but the effect of central LKB1 on diet-induced obesity (DIO) is unknown. Therefore, we examined whether LKB1 over-expression in the hypothalamus can inhibit the development of obesity. Adult male Sprague-Dawley rats were anesthetized and placed in a stereotaxic apparatus. LKB1-AAV-EGFP (2.0 × 108 or 2.0 × 1010 vector genomes) or Control-AAV-EGFP (2.0 × 108 vector genomes) was injected into the third ventricle. After administration, the rats were fed a high-fat diet (HFD) for 9 weeks to induce obesity. Rats fed a chow fat diet were used as normal controls. LKB1 delivery decreased body weight, energy intake, fat mass, and serum lipid levels. LKB1 also improved HFD-induced hepatic fatty degeneration. Interestingly, LKB1 over-expression in the hypothalamus activated the AMPK-POMC neurons-sympathetic nervous system (SNS) axis, which can release epinephrine to promote white fat browning. Conversely, the elevated expression of MC3R/MC4R inhibited food intake. These two factors worked together to inhibit the development of obesity. LKB1 in the hypothalamus may have therapeutic potential for DIO through the activation of the AMPK-POMC neurons-SNS axis. © 2018 The Author(s). Published by S. Karger AG, Basel.

Nuclear overexpression of the overexpressed in lung cancer 1 predicts worse prognosis in gastric adenocarcinoma.

PubMed

Wang, Jue; Shen, Hongchang; Fu, Guobin; Zhao, Dandan; Wang, Weibo

2017-02-07

We have performed this retrospective study to elucidate whether elevated expression of the overexpressed in lung cancer 1 (OLC1) was related to the clinicopathological parameters and prognosis of patients with gastric adenocarcinoma. Additionally, different effects of various subcellular OLC1 expression on gastric adeno-carcinogenesis were focused on in our study. Both overall and subcellular expression of OLC1 was evaluated by immunohistochemistry(IHC) via tissue microarrays from total 393 samples. The Kaplan-Meier method and Cox's proportional hazard model were exerted to further explore the correlation between OLC1 and prognosis. Total overexpression of OLC1 was significantly associated with stage (P = 0.004) and differentiation (P = 0.009), and only the strong total expression could predict a poor prognosis (HR = 1.31, P = 0.04). There were significant associations found between nuclear overexpression and tumor invasion depth(P = 0.002), lymph node (P < 0.001), stage (P = 0.004), differentiation (P < 0.001) and smoking history (P = 0.045). Furthermore, over-expressed nuclear OLC1 protein could be an independent risk factor for gastric adenocarcinoma (univariate: HR = 1.43, P = 0.003; multivariate: HR = 1.39, P = 0.011). In general, both total and nuclear overexpression of OLC1 could be the signs of gastric adeno-carcinogenesis, which might be served as the biomarkers for diagnosis at an early stage, even at the onset of tumorigenesis. Rather than the total expression, nuclear overexpression of OLC1 was correlated with most clinicopathological parameters and could predict a poor overall survival as an independent factor for prognosis, which made it a more effective and sensitive biomarker for gastric adenocarcinoma.

A method for accelerated trait conversion in plant breeding.

PubMed

Lewis, Ramsey S; Kernodle, S P

2009-05-01

Backcrossing is often used in cultivar development to transfer one or a few genes to desired genetic backgrounds. The duration necessary to complete such 'trait conversions' is largely dependent upon generation times. Constitutive overexpression of the Arabidopsis thaliana gene FT (FLOWERING LOCUS T) induces early-flowering in many plants. Here, we used tobacco (Nicotiana tabacum L.) as a model system to propose and examine aspects of a modified backcross procedure where transgenic FT overexpression is used to reduce generation time and accelerate gene transfer. In this method, the breeder would select for an FT transgene insertion and the trait(s) of interest at each backcross generation except the last. In the final generation, selection would be conducted for the trait(s) of interest, but against FT, to generate the backcross-derived trait conversion. We demonstrate here that constitutive FT overexpression functions to dramatically reduce days-to-flower similarly in diverse tobacco genetic backgrounds. FT-containing plants flowered in an average of 39 days, in comparison with 87-138 days for non-FT plants. Two FT transgene insertions were found to segregate independently of several disease resistance genes often the focus of backcrossing in tobacco. In addition, no undesirable epigenetic effects on flowering time were observed once FT was segregated away. The proposed system would reduce the time required to complete a trait conversion in tobacco by nearly one-half. These features suggest the possible value of this modified backcrossing system for tobacco or other crop species where long generation times or photoperiod sensitivity may impede timely trait conversion.

MAL2 and tumor protein D52 (TPD52) are frequently overexpressed in ovarian carcinoma, but differentially associated with histological subtype and patient outcome.

PubMed

Byrne, Jennifer A; Maleki, Sanaz; Hardy, Jayne R; Gloss, Brian S; Murali, Rajmohan; Scurry, James P; Fanayan, Susan; Emmanuel, Catherine; Hacker, Neville F; Sutherland, Robert L; Defazio, Anna; O'Brien, Philippa M

2010-09-17

The four-transmembrane MAL2 protein is frequently overexpressed in breast carcinoma, and MAL2 overexpression is associated with gain of the corresponding locus at chromosome 8q24.12. Independent expression microarray studies predict MAL2 overexpression in ovarian carcinoma, but these had remained unconfirmed. MAL2 binds tumor protein D52 (TPD52), which is frequently overexpressed in ovarian carcinoma, but the clinical significance of MAL2 and TPD52 overexpression was unknown. Immunohistochemical analyses of MAL2 and TPD52 expression were performed using tissue microarray sections including benign, borderline and malignant epithelial ovarian tumours. Inmmunohistochemical staining intensity and distribution was assessed both visually and digitally. MAL2 and TPD52 were significantly overexpressed in high-grade serous carcinomas compared with serous borderline tumours. MAL2 expression was highest in serous carcinomas relative to other histological subtypes, whereas TPD52 expression was highest in clear cell carcinomas. MAL2 expression was not related to patient survival, however high-level TPD52 staining was significantly associated with improved overall survival in patients with stage III serous ovarian carcinoma (log-rank test, p < 0.001; n = 124) and was an independent predictor of survival in the overall carcinoma cohort (hazard ratio (HR), 0.498; 95% confidence interval (CI), 0.34-0.728; p < 0.001; n = 221), and in serous carcinomas (HR, 0.440; 95% CI, 0.294-0.658; p < 0.001; n = 182). MAL2 is frequently overexpressed in ovarian carcinoma, and TPD52 overexpression is a favourable independent prognostic marker of potential value in the management of ovarian carcinoma patients.

[Overexpressed miRNA-134b inhibits proliferation and invasion of CD133+ U87 glioma stem cells].

PubMed

Liu, Yifeng; Zhang, Baochao; Wen, Changming; Wen, Gongling; Zhou, Guoping; Zhang, Jingwei; He, Haifa; Wang, Ning; Li, Wei

2017-05-01

Objective To investigate the role of microRNA-134b (miR-134b) in the tumorigenesis of glioma stem cells (GSCs) and the possible molecular mechanism. Methods Real-time quantitative PCR (qRT-PCR) was used to evalate the expression of miR-134b in CD133 + and CD133 - U87 GSCs. A lentiviral vector overexpressing miR-134b in U87 GSCs was constructed, and the effect of miR-134b overexpression on matrix metalloproteinase-2 (MMP-2), MMP-9 and MMP-12 expressions at both mRNA and protein levels were detected by qRT-PCR and Western blotting, respectively. Transwell TM assay was performed to determine the effect of miR-134b overexpression on GSCs invasion ability. Tumor xenograft models in nude mice were established to evaluate the effect of miR-134b overexpression on tumorgenesis in vivo. Results The qRT-PCR showed that, compared with CD133 - cells, miR-134b was significantly down-regulated in CD133 + cells. Cell line over-expressing miR-134b was successfully established, and miR-134b was up-regulated significantly compared with empty vector control. Overexpression of miR-134b remarkably inhibited the invasion of U87 GSCs and the expression of MMP-12. However, overexpression of miR-134b did not affect MMP-2 and MMP-9 expressions. miR-134b also suppressed U87 GSCs xenograft growth in vivo. Tumor volume in tumor xenograft model group was significantly lower than that in control group, and tumor weight decreased by 42% in the former group. Conclusion Overexpression of miR-134b inhibits the growth and invasion of CD133 + GSCs.

Transgenic soybean overexpressing GmSamT1 exhibits resistance to multiple-HG types of soybean cyst nematode Heterodera glycines

USDA-ARS?s Scientific Manuscript database

Soybean (Glycine max (L.) Merr.) salicylic acid methyl transferase (GmSAMT1) catalyzes the conversion of salicylic acid to methyl salicylate. Prior results showed that when GmSAMT1 was overexpressed in transgenic soybean hairy roots, resistance is conferred against soybean cyst nematode (SCN), Heter...

FOXP3 over-expression inhibits melanoma tumorigenesis via effects on proliferation and apoptosis.

PubMed

Tan, BeeShin; Anaka, Matthew; Deb, Siddhartha; Freyer, Claudia; Ebert, Lisa M; Chueh, Anderly C; Al-Obaidi, Sheren; Behren, Andreas; Jayachandran, Aparna; Cebon, Jonathan; Chen, Weisan; Mariadason, John M

2014-01-15

The Forkhead box P3 (FOXP3) transcription factor is the key driver of regulatory T cell (Treg cells) differentiation and immunosuppressive function. In addition, FOXP3 has been reported to be expressed in many tumors, including melanoma. However, its role in tumorigenesis is conflicting, with both tumor suppressive and tumor promoting functions described. The aim of the current study was to characterize the expression and function of FOXP3 in melanoma. FOXP3 expression was detected by immunohistochemistry (IHC) in 12% (18/146) of stage III and IV melanomas. However expression was confined to fewer than 1% of cells in these tumors. Stable over-expression of FOXP3 in the SK-MEL-28 melanoma cell line reduced cell proliferation and clonogenicity in vitro, and reduced xenograft growth in vivo. FOXP3 over-expression also increased pigmentation and the rate of apoptosis of SK-MEL-28 cells. Based on its infrequent expression in human melanoma, and its growth inhibitory and pro-apoptotic effect in over-expressing melanoma cells, we conclude that FOXP3 is not likely to be a key tumor suppressor or promoter in melanoma.

Glutathione peroxidase 4 overexpression inhibits ROS-induced cell death in diffuse large B-cell lymphoma.

PubMed

Kinowaki, Yuko; Kurata, Morito; Ishibashi, Sachiko; Ikeda, Masumi; Tatsuzawa, Anna; Yamamoto, Masahide; Miura, Osamu; Kitagawa, Masanobu; Yamamoto, Kouhei

2018-02-20

Regulation of oxidative stress and redox systems has important roles in carcinogenesis and cancer progression, and for this reason has attracted much attention as a new area of cancer therapeutic targets. Glutathione peroxidase 4 (GPX4), an antioxidant enzyme, has biological important functions such as signaling cell death by suppressing peroxidation of membrane phospholipids. However, few studies exist on the expression and clinical relevance of GPX4 in malignant lymphomas such as diffuse large B-cell lymphoma. In this study, we assessed the expression of GPX4 immunohistochemically. GPX4 was expressed in 35.5% (33/93) cases of diffuse large B-cell lymphoma. The GPX4-positive group had poor overall survival (P = 0.0032) and progression-free survival (P = 0.0004) compared with those of the GPX4-negative group. In a combined analysis of GPX4 and 8-hydroxydeoxyguanosine (8-OHdG), an oxidative stress marker, there was a negative correlation between GPX4 and 8-hydroxydeoxyguanosine (P = 0.0009). The GPX4-positive and 8-hydroxydeoxyguanosine-negative groups had a significantly worse prognosis than the other groups in both overall survival (P = 0.0170) and progression-free survival (P = 0.0005). These results suggest that the overexpression of GPX4 is an independent prognostic predictor in diffuse large B-cell lymphoma. Furthermore, in vitro analysis demonstrated that GPX4-overexpressing cells were resistant to reactive oxygen species-induced cell death (P = 0.0360). Conversely, GPX4-knockdown cells were sensitive to reactive oxygen species-induced cell death (P = 0.0111). From these data, we conclude that GPX4 regulates reactive oxygen species-induced cell death. Our results suggest a novel therapeutic strategy using the mechanism of ferroptosis, as well as a novel prognostic predictor of diffuse large B-cell lymphoma.

A new-generation of Bacillus subtilis cell factory for further elevated scyllo-inositol production.

PubMed

Tanaka, Kosei; Natsume, Ayane; Ishikawa, Shu; Takenaka, Shinji; Yoshida, Ken-Ichi

2017-04-21

A stereoisomer of inositol, scyllo-inositol (SI), has been regarded as a promising therapeutic agent for Alzheimer's disease. However, this compound is relatively rare, whereas another stereoisomer of inositol, myo-inositol (MI) is abundant in nature. Bacillus subtilis 168 has the ability to metabolize inositol stereoisomers, including MI and SI. Previously, we reported a B. subtilis cell factory with modified inositol metabolism that converts MI into SI in the culture medium. The strain was constructed by deleting all genes related to inositol metabolism and overexpressing key enzymes, IolG and IolW. By using this strain, 10 g/l of MI initially included in the medium was completely converted into SI within 48 h of cultivation in a rich medium containing 2% (w/v) Bacto soytone. When the initial concentration of MI was increased to 50 g/l, conversion was limited to 15.1 g/l of SI. Therefore, overexpression systems of IolT and PntAB, the main transporter of MI in B. subtilis and the membrane-integral nicotinamide nucleotide transhydrogenase in Escherichia coli respectively, were additionally introduced into the B. subtilis cell factory, but the conversion efficiency hardly improved. We systematically determined the amount of Bacto soytone necessary for ultimate conversion, which was 4% (w/v). As a result, the conversion of SI reached to 27.6 g/l within 48 h of cultivation. The B. subtilis cell factory was improved to yield a SI production rate of 27.6 g/l/48 h by simultaneous overexpression of IolT and PntAB, and by addition of 4% (w/v) Bacto soytone in the conversion medium. The concentration of SI was increased even in the stationary phase perhaps due to nutrients in the Bacto soytone that contribute to the conversion process. Thus, MI conversion to SI may be further optimized via identification and control of these unknown nutrients.

Homodimeric β-Galactosidase from Lactobacillus delbrueckii subsp. bulgaricus DSM 20081: Expression in Lactobacillus plantarum and Biochemical Characterization

PubMed Central

2012-01-01

The lacZ gene from Lactobacillus delbrueckii subsp. bulgaricus DSM 20081, encoding a β-galactosidase of the glycoside hydrolase family GH2, was cloned into different inducible lactobacillal expression vectors for overexpression in the host strain Lactobacillus plantarum WCFS1. High expression levels were obtained in laboratory cultivations with yields of approximately 53000 U of β-galactosidase activity per liter of medium, which corresponds to ∼170 mg of recombinant protein per liter and β-galactosidase levels amounting to 63% of the total intracellular protein of the host organism. The wild-type (nontagged) and histidine-tagged recombinant enzymes were purified to electrophoretic homogeneity and further characterized. β-Galactosidase from L. bulgaricus was used for lactose conversion and showed very high transgalactosylation activity. The maximum yield of galacto-oligosaccharides (GalOS) was approximately 50% when using an initial concentration of 600 mM lactose, indicating that the enzyme can be of interest for the production of GalOS. PMID:22283494

Homodimeric β-galactosidase from Lactobacillus delbrueckii subsp. bulgaricus DSM 20081: expression in Lactobacillus plantarum and biochemical characterization.

PubMed

Nguyen, Tien-Thanh; Nguyen, Hoang Anh; Arreola, Sheryl Lozel; Mlynek, Georg; Djinović-Carugo, Kristina; Mathiesen, Geir; Nguyen, Thu-Ha; Haltrich, Dietmar

2012-02-22

The lacZ gene from Lactobacillus delbrueckii subsp. bulgaricus DSM 20081, encoding a β-galactosidase of the glycoside hydrolase family GH2, was cloned into different inducible lactobacillal expression vectors for overexpression in the host strain Lactobacillus plantarum WCFS1. High expression levels were obtained in laboratory cultivations with yields of approximately 53000 U of β-galactosidase activity per liter of medium, which corresponds to ~170 mg of recombinant protein per liter and β-galactosidase levels amounting to 63% of the total intracellular protein of the host organism. The wild-type (nontagged) and histidine-tagged recombinant enzymes were purified to electrophoretic homogeneity and further characterized. β-Galactosidase from L. bulgaricus was used for lactose conversion and showed very high transgalactosylation activity. The maximum yield of galacto-oligosaccharides (GalOS) was approximately 50% when using an initial concentration of 600 mM lactose, indicating that the enzyme can be of interest for the production of GalOS.

Fibronectin regulates Wnt7a signaling and satellite cell expansion

PubMed Central

Bentzinger, C. Florian; Wang, Yu Xin; von Maltzahn, Julia; Soleimani, Vahab D.; Yin, Hang; Rudnicki, Michael A.

2012-01-01

SUMMARY The influence of the extracellular matrix (ECM) within the stem cell niche remains poorly understood. We found that Syndecan-4 (Sdc4) and Frizzled-7 (Fzd7) form a co-receptor complex in satellite cells and that binding of the ECM glycoprotein Fibronectin (FN) to Sdc4 stimulates the ability of Wnt7a to induce the symmetric expansion of satellite stem cells. Newly activated satellite cells dynamically remodel their niche by transient high-level expression of FN. Knockdown of FN in prospectively isolated satellite cells severely impaired their ability to repopulate the satellite cell niche. Conversely, in vivo over-expression of FN with Wnt7a dramatically stimulated the expansion of satellite stem cells in regenerating muscle. Therefore, activating satellite cells remodel their niche through autologous expression of FN that provides feedback to stimulate Wnt7a signaling through the Fzd7/Sdc4 co-receptor complex. Thus, FN and Wnt7a together regulate the homeostatic levels of satellite stem cells and satellite myogenic cells during regenerative myogenesis. PMID:23290138

miR-618 Inhibits Prostate Cancer Migration and Invasion by Targeting FOXP2.

PubMed

Song, Xian-Lu; Tang, Yao; Lei, Xiang-Hui; Zhao, Shan-Chao; Wu, Zi-Qing

2017-01-01

miRNAs play critical role in the development and progression of prostate cancer. Here we studied the role of miR-618 in prostate cancer migration and invasion. miR-618 was downregulated in metastatic androgen-independent prostate cancer (AIPC), patients with low miR-618 had poor outcome. Overexpression of miR-618 inhibited migration and invasion and induced mesenchymal to epithelial transition (MET). Conversely, knockdown of miR-618 promoted migration and invasion and induced epithelial to mesenchymal transition (EMT). FOXP2 was the direct target of miR-618, and promoted TGF-β expression, inhibition of TGF-β reversed the effect of miR-618 knockdown. We further analyzed the correlation between miR-618 expression and FOXP2 in human prostate cancer tissues, and found there was a negative correlation between miR-618 expression and FOXP2 levels. In conclusion, we found miR-618 inhibited prostate cancer migration and invasion by targeting FOXP2 and inhibiting TGF-β.

Immunohistochemical expression of cyclooxygenase-2 (COX-2) in oral nevi and melanoma.

PubMed

de Souza do Nascimento, Juliana; Carlos, Román; Delgado-Azañero, Wilson; Mosqueda Taylor, Adalberto; de Almeida, Oslei Paes; Romañach, Mário José; de Andrade, Bruno Augusto Benevenuto

2016-07-01

Cyclooxygenase-2 (COX-2) catalyses the conversion of arachidonic acid to prostaglandin, and its overexpression has been demonstrated in different malignant tumors, including cutaneous melanoma. However, no data about the expression of this protein in oral melanocytic lesions are available to date. The aim of this study was to evaluate the immunohistochemical expression of COX-2 in oral nevi and melanomas, comparing the results with correspondent cutaneous lesions. COX-2 was evaluated by immunohistochemistry in 49 oral melanocytic lesions, including 36 intramucosal nevi and 13 primary oral melanomas, and in four cutaneous nevi and eight melanomas. All cases of oral and cutaneous melanomas were positive for COX-2. On the other hand, all oral and cutaneous melanocytic nevi were negative. COX-2 is highly positive in oral melanomas and negative in oral nevi and might represent a useful marker to distinguish melanocytic lesions of the oral cavity. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

MyoD expression restores defective myogenic differentiation of human mesoangioblasts from inclusion-body myositis muscle.

PubMed

Morosetti, Roberta; Mirabella, Massimiliano; Gliubizzi, Carla; Broccolini, Aldobrando; De Angelis, Luciana; Tagliafico, Enrico; Sampaolesi, Maurilio; Gidaro, Teresa; Papacci, Manuela; Roncaglia, Enrica; Rutella, Sergio; Ferrari, Stefano; Tonali, Pietro Attilio; Ricci, Enzo; Cossu, Giulio

2006-11-07

Inflammatory myopathies (IM) are acquired diseases of skeletal muscle comprising dermatomyositis (DM), polymyositis (PM), and inclusion-body myositis (IBM). Immunosuppressive therapies, usually beneficial for DM and PM, are poorly effective in IBM. We report the isolation and characterization of mesoangioblasts, vessel-associated stem cells, from diagnostic muscle biopsies of IM. The number of cells isolated, proliferation rate and lifespan, markers expression, and ability to differentiate into smooth muscle do not differ among normal and IM mesoangioblasts. At variance with normal, DM and PM mesoangioblasts, cells isolated from IBM, fail to differentiate into skeletal myotubes. These data correlate with lack in connective tissue of IBM muscle of alkaline phosphatase (ALP)-positive cells, conversely dramatically increased in PM and DM. A myogenic inhibitory basic helix-loop-helix factor B3 is highly expressed in IBM mesoangioblasts. Indeed, silencing this gene or overexpressing MyoD rescues the myogenic defect of IBM mesoangioblasts, opening novel cell-based therapeutic strategies for this crippling disorder.

MyoD expression restores defective myogenic differentiation of human mesoangioblasts from inclusion-body myositis muscle

PubMed Central

Morosetti, Roberta; Mirabella, Massimiliano; Gliubizzi, Carla; Broccolini, Aldobrando; De Angelis, Luciana; Tagliafico, Enrico; Sampaolesi, Maurilio; Gidaro, Teresa; Papacci, Manuela; Roncaglia, Enrica; Rutella, Sergio; Ferrari, Stefano; Tonali, Pietro Attilio; Ricci, Enzo; Cossu, Giulio

2006-01-01

Inflammatory myopathies (IM) are acquired diseases of skeletal muscle comprising dermatomyositis (DM), polymyositis (PM), and inclusion-body myositis (IBM). Immunosuppressive therapies, usually beneficial for DM and PM, are poorly effective in IBM. We report the isolation and characterization of mesoangioblasts, vessel-associated stem cells, from diagnostic muscle biopsies of IM. The number of cells isolated, proliferation rate and lifespan, markers expression, and ability to differentiate into smooth muscle do not differ among normal and IM mesoangioblasts. At variance with normal, DM and PM mesoangioblasts, cells isolated from IBM, fail to differentiate into skeletal myotubes. These data correlate with lack in connective tissue of IBM muscle of alkaline phosphatase (ALP)-positive cells, conversely dramatically increased in PM and DM. A myogenic inhibitory basic helix–loop–helix factor B3 is highly expressed in IBM mesoangioblasts. Indeed, silencing this gene or overexpressing MyoD rescues the myogenic defect of IBM mesoangioblasts, opening novel cell-based therapeutic strategies for this crippling disorder. PMID:17077152

The novel tumour suppressor Madm regulates stem cell competition in the Drosophila testis

PubMed Central

Singh, Shree Ram; Liu, Ying; Zhao, Jiangsha; Zeng, Xiankun; Hou, Steven X.

2016-01-01

Stem cell competition has emerged as a mechanism for selecting fit stem cells/progenitors and controlling tumourigenesis. However, little is known about the underlying molecular mechanism. Here we identify Mlf1-adaptor molecule (Madm), a novel tumour suppressor that regulates the competition between germline stem cells (GSCs) and somatic cyst stem cells (CySCs) for niche occupancy. Madm knockdown results in overexpression of the EGF receptor ligand vein (vn), which further activates EGF receptor signalling and integrin expression non-cell autonomously in CySCs to promote their overproliferation and ability to outcompete GSCs for niche occupancy. Conversely, expressing a constitutively activated form of the Drosophila JAK kinase (hopTum−l) promotes Madm nuclear translocation, and suppresses vn and integrin expression in CySCs that allows GSCs to outcompete CySCs for niche occupancy and promotes GSC tumour formation. Tumour suppressor-mediated stem cell competition presented here could be a mechanism of tumour initiation in mammals. PMID:26792023

The novel tumour suppressor Madm regulates stem cell competition in the Drosophila testis.

PubMed

Singh, Shree Ram; Liu, Ying; Zhao, Jiangsha; Zeng, Xiankun; Hou, Steven X

2016-01-21

Stem cell competition has emerged as a mechanism for selecting fit stem cells/progenitors and controlling tumourigenesis. However, little is known about the underlying molecular mechanism. Here we identify Mlf1-adaptor molecule (Madm), a novel tumour suppressor that regulates the competition between germline stem cells (GSCs) and somatic cyst stem cells (CySCs) for niche occupancy. Madm knockdown results in overexpression of the EGF receptor ligand vein (vn), which further activates EGF receptor signalling and integrin expression non-cell autonomously in CySCs to promote their overproliferation and ability to outcompete GSCs for niche occupancy. Conversely, expressing a constitutively activated form of the Drosophila JAK kinase (hop(Tum-l)) promotes Madm nuclear translocation, and suppresses vn and integrin expression in CySCs that allows GSCs to outcompete CySCs for niche occupancy and promotes GSC tumour formation. Tumour suppressor-mediated stem cell competition presented here could be a mechanism of tumour initiation in mammals.

Signal Transducer and Activator of Transcription 1 Plays a Pivotal Role in RET/PTC3 Oncogene-induced Expression of Indoleamine 2,3-Dioxygenase 1.

PubMed

Moretti, Sonia; Menicali, Elisa; Nucci, Nicole; Voce, Pasquale; Colella, Renato; Melillo, Rosa Marina; Liotti, Federica; Morelli, Silvia; Fallarino, Francesca; Macchiarulo, Antonio; Santoro, Massimo; Avenia, Nicola; Puxeddu, Efisio

2017-02-03

Indoleamine 2,3-dioxygenase 1 (IDO1) is a single chain oxidoreductase that catalyzes tryptophan degradation to kynurenine. In cancer, it exerts an immunosuppressive function as part of an acquired mechanism of immune escape. Recently, we demonstrated that IDO1 expression is significantly higher in all thyroid cancer histotypes compared with normal thyroid and that its expression levels correlate with T regulatory (Treg) lymphocyte densities in the tumor microenvironment. BRAF V600E - and RET/PTC3-expressing PcCL3 cells were used as cellular models for the evaluation of IDO1 expression in thyroid carcinoma cells and for the study of involved signal transduction pathways. BRAF V600E -expressing PcCL3 cells did not show IDO1 expression. Conversely, RET/PTC3-expressing cells were characterized by a high IDO1 expression. Moreover, we found that, the STAT1-IRF1 pathway was instrumental for IDO1 expression in RET/PTC3 expressing cells. In detail, RET/PTC3 induced STAT1 overexpression and phosphorylation at Ser-727 and Tyr-701. STAT1 transcriptional regulation appeared to require activation of the canonical NF-κB pathway. Conversely, activation of the MAPK and PI3K-AKT pathways primarily regulated Ser-727 phosphorylation, whereas a physical interaction between RET/PTC3 and STAT1, followed by a direct tyrosine phosphorylation event, was necessary for STAT1 Tyr-701 phosphorylation. These data provide the first evidence of a direct link between IDO1 expression and the oncogenic activation of RET in thyroid carcinoma and describe the involved signal transduction pathways. Moreover, they suggest possible novel molecular targets for the abrogation of tumor microenvironment immunosuppression. The detection of those targets is becoming increasingly important to yield the full function of novel immune checkpoint inhibitors. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Redox susceptibility of SOD1 mutants is associated with the differential response to CCS over-expression in vivo.

PubMed

Son, Marjatta; Fu, Qiao; Puttaparthi, Krishna; Matthews, Christina M; Elliott, Jeffrey L

2009-04-01

Over-expression of CCS in G93A SOD1 mice accelerates neurological disease and enhances mitochondrial pathology. We studied the effect of CCS over-expression in transgenic mice expressing G37R, G86R or L126Z SOD1 mutations in order to understand factors which influence mitochondrial dysfunction. Over-expression of CCS markedly decreased survival and produced mitochondrial vacuolation in G37R SOD1 mice but not in G86R or L126Z SOD1 mice. Moreover, CCS/G37R SOD1 spinal cord showed specific reductions in mitochondrial complex IV subunits consistent with an isolated COX deficiency, while no such reductions were detected in CCS/G86R or CCS/L126Z SOD1 mice. CCS over-expression increased the ratio of reduced to oxidized SOD1 monomers in the spinal cords of G37R SOD1 as well as G93A SOD1 mice, but did not influence the redox state of G86R or L126Z SOD1 monomers. The effects of CCS on disease are SOD1 mutation dependent and correlate with SOD1 redox susceptibility.

Enhancing solubility of deoxyxylulose phosphate pathway enzymes for microbial isoprenoid production

PubMed Central

2012-01-01

Background Recombinant proteins are routinely overexpressed in metabolic engineering. It is well known that some over-expressed heterologous recombinant enzymes are insoluble with little or no enzymatic activity. This study examined the solubility of over-expressed homologous enzymes of the deoxyxylulose phosphate pathway (DXP) and the impact of inclusion body formation on metabolic engineering of microbes. Results Four enzymes of this pathway (DXS, ISPG, ISPH and ISPA), but not all, were highly insoluble, regardless of the expression systems used. Insoluble dxs (the committed enzyme of DXP pathway) was found to be inactive. Expressions of fusion tags did not significantly improve the solubility of dxs. However, hypertonic media containing sorbitol, an osmolyte, successfully doubled the solubility of dxs, with the concomitant improvement in microbial production of the metabolite, DXP. Similarly, sorbitol significantly improved the production of soluble and functional ERG12, the committed enzyme in the mevalonate pathway. Conclusion This study demonstrated the unanticipated findings that some over-expressed homologous enzymes of the DXP pathway were highly insoluble, forming inclusion bodies, which affected metabolite formation. Sorbitol was found to increase both the solubility and function of some of these over-expressed enzymes, a strategy to increase the production of secondary metabolites. PMID:23148661

BRCA1-IRIS regulates cyclin D1 expression in breast cancer cells

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

Nakuci, Enkeleda; Mahner, Sven; DiRenzo, James

2006-10-01

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

Predictive value of EGFR overexpression and gene amplification on icotinib efficacy in patients with advanced esophageal squamous cell carcinoma

PubMed Central

Fan, Qingxia; Lu, Ping; Ma, Changwu; Liu, Wei; Liu, Ying; Li, Weiwei; Hu, Shaoxuan; Ling, Yun; Guo, Lei; Ying, Jianming; Huang, Jing

2016-01-01

This study aimed to search for a molecular marker for targeted epithelial growth factor receptor (EGFR) inhibitor Icotinib by analyzing protein expression and amplification of EGFR proto-oncogene in esophageal squamous cell carcinoma (ESCC) patients. Immunohistochemistry and fluorescence in situ hybridization (FISH) was used to assess EGFR expression and gene amplification status in 193 patients with ESCC. We also examined the association between EGFR overexpression and the efficacy of a novel EGFR TKI, icotinib, in 62 ESCC patients. Of the 193 patients, 95 (49.2%) patients showed EGFR overexpression (3+), and 47(24.4%) patients harbored EGFR FISH positivity. EGFR overexpression was significantly correlated with clinical stage and lymph node metastasis (p<0.05). In addition, EGFR overexpression was significantly correlated with EGFR FISH positivity (p<0.001). Among the 62 patients who received icotinib, the response rate was 17.6% for patients with high EGFR-expressing tumors, which was markedly higher than the rate (0%) for patients with low to moderate EGFR-expressing tumors (p=0.341). Furthermore, all cases responded to icotinib showed EGFR overexpression. In conclusion, our study suggests that EGFR overexpression might potentially be used in predicting the efficacy in patients treated with Icotinib. These data have implications for both clinical trial design and therapeutic strategies. PMID:27013591

Predictive value of EGFR overexpression and gene amplification on icotinib efficacy in patients with advanced esophageal squamous cell carcinoma.

PubMed

Wang, Xi; Niu, Haitao; Fan, Qingxia; Lu, Ping; Ma, Changwu; Liu, Wei; Liu, Ying; Li, Weiwei; Hu, Shaoxuan; Ling, Yun; Guo, Lei; Ying, Jianming; Huang, Jing

2016-04-26

This study aimed to search for a molecular marker for targeted epithelial growth factor receptor (EGFR) inhibitor Icotinib by analyzing protein expression and amplification of EGFR proto-oncogene in esophageal squamous cell carcinoma (ESCC) patients.Immunohistochemistry and fluorescence in situ hybridization (FISH) was used to assess EGFR expression and gene amplification status in 193 patients with ESCC. We also examined the association between EGFR overexpression and the efficacy of a novel EGFR TKI, icotinib, in 62 ESCC patients.Of the 193 patients, 95 (49.2%) patients showed EGFR overexpression (3+), and 47(24.4%) patients harbored EGFR FISH positivity. EGFR overexpression was significantly correlated with clinical stage and lymph node metastasis (p<0.05). In addition, EGFR overexpression was significantly correlated with EGFR FISH positivity (p<0.001). Among the 62 patients who received icotinib, the response rate was 17.6% for patients with high EGFR-expressing tumors, which was markedly higher than the rate (0%) for patients with low to moderate EGFR-expressing tumors (p=0.341). Furthermore, all cases responded to icotinib showed EGFR overexpression.In conclusion, our study suggests that EGFR overexpression might potentially be used in predicting the efficacy in patients treated with Icotinib. These data have implications for both clinical trial design and therapeutic strategies.

Transgenic studies reveal the positive role of LeEIL-1 in regulating shikonin biosynthesis in Lithospermum erythrorhizon hairy roots.

PubMed

Fang, Rongjun; Zou, Ailan; Zhao, Hua; Wu, Fengyao; Zhu, Yu; Zhao, Hu; Liao, Yonghui; Tang, Ren-Jie; Pang, Yanjun; Yang, Rongwu; Wang, Xiaoming; Qi, Jinliang; Lu, Guihua; Yang, Yonghua

2016-05-26

The phytohormone ethylene (ET) is a key signaling molecule for inducing the biosynthesis of shikonin and its derivatives, which are secondary metabolites in Lithospermum erythrorhizon. Although ETHYLENE INSENSITIVE3 (EIN3)/EIN3-like proteins (EILs) are crucial transcription factors in ET signal transduction pathway, the possible function of EIN3/EIL1 in shikonin biosynthesis remains unknown. In this study, by targeting LeEIL-1 (L. erythrorhizon EIN3-like protein gene 1) at the expression level, we revealed the positive regulatory effect of LeEIL-1 on shikonin formation. The mRNA level of LeEIL-1 was significantly up-regulated and down-regulated in the LeEIL-1-overexpressing hairy root lines and LeEIL-1-RNAi hairy root lines, respectively. Specifically, LeEIL-1 overexpression resulted in increased transcript levels of the downstream gene of ET signal transduction pathway (LeERF-1) and a subset of genes for shikonin formation, excretion and/or transportation (LePAL, LeC4H-2, Le4CL-1, HMGR, LePGT-1, LeDI-2, and LePS-2), which was consistent with the enhanced shikonin contents in the LeEIL-1-overexpressing hairy root lines. Conversely, LeEIL-1-RNAi dramatically repressed the expression of the above genes and significantly reduced shikonin production. The results revealed that LeEIL-1 is a positive regulator of the biosynthesis of shikonin and its derivatives in L. erythrorhizon hairy roots. Our findings gave new insights into the molecular regulatory mechanism of ET in shikonin biosynthesis. LeEIL-1 could be a crucial target gene for the genetic engineering of shikonin biosynthesis.

Differential role of PTEN in transforming growth factor β (TGF-β) effects on proliferation and migration in prostate cancer cells.

PubMed

Kimbrough-Allah, Mawiyah N; Millena, Ana C; Khan, Shafiq A

2018-04-01

Transforming growth factor-β (TGF-β) acts as a tumor suppressor in normal epithelial cells but as a tumor promoter in advanced prostate cancer cells. PI3-kinase pathway mediates TGF-β effects on prostate cancer cell migration and invasion. PTEN inhibits PI3-kinase pathway and is frequently mutated in prostate cancers. We investigated possible role(s) of PTEN in TGF-β effects on proliferation and migration in prostate cancer cells. Expression of PTEN mRNA and proteins were determined using RT-PCR and Western blotting in RWPE1 and DU145 cells. We also studied the role of PTEN in TGF-β effects on cell proliferation and migration in DU145 cells after transient silencing of endogenous PTEN. Conversely, we determined the role of PTEN in cell proliferation and migration after over-expression of PTEN in PC3 cells which lack endogenous PTEN. TGF-β1 and TGF-β3 had no effect on PTEN mRNA levels but both isoforms increased PTEN protein levels in DU145 and RWPE1 cells indicating that PTEN may mediate TGF-β effects on cell proliferation. Knockdown of PTEN in DU145 cells resulted in significant increase in cell proliferation which was not affected by TGF-β isoforms. PTEN overexpression in PC3 cells inhibited cell proliferation. Knockdown of endogenous PTEN enhanced cell migration in DU145 cells, whereas PTEN overexpression reduced migration in PC3 cells and reduced phosphorylation of AKT in response to TGF-β. We conclude that PTEN plays a role in inhibitory effects of TGF-β on cell proliferation whereas its absence may enhance TGF-β effects on activation of PI3-kinase pathway and cell migration. © 2018 Wiley Periodicals, Inc.

MicroRNA-24 Modulates Staphylococcus aureus-Induced Macrophage Polarization by Suppressing CHI3L1.

PubMed

Jingjing, Zhang; Nan, Zhang; Wei, Wu; Qinghe, Guo; Weijuan, Wang; Peng, Wang; Xiangpeng, Wang

2017-06-01

Macrophages play a crucial role in host innate anti-Staphylococcus aureus defense, which is tightly regulated by multiple factors, including microRNAs. A recent study showed that miR-24 plays an important role in macrophage polarization. Here, we investigated the biological function of miR-24 in S. aureus-stimulated macrophages. The results revealed that miR-24 expression was significantly decreased in both human and mouse macrophage cell lines with S. aureus stimulation in a time-dependent manner. Moreover, miR-24 overexpression significantly decreased the production of M1 phenotype markers, such as IL-6, iNOS, TNF-α, CD86, and CD80, whereas it increased the production of M2 markers, such as Arg1, CCL17, CCL22, CD163, and CD206, in S. aureus-stimulated macrophages. Conversely, knockdown of miR-24 promoted M1 macrophage polarization but diminished M2 macrophage polarization in S. aureus-stimulated macrophages. Furthermore, CHI3L1 was predicted as a target gene of miR-24 using bioinformatics software and identified by luciferase reporter assay. Additionally, miR-24 overexpression inhibited CHI3L1 expression and downregulated the downstream MAPK pathway in S. aureus-stimulated macrophages. Finally, CHI3L1 overexpression rescued macrophage polarization and MAPK pathway inhibition induced by miR-24 mimic transfection in S. aureus-stimulated macrophages. In conclusion, the data suggest that miR-24 serves as a molecular regulator in S. aureus-induced macrophage polarization through targeting of CHI3L1 and regulation of the MAPK pathway, which may provide a promising therapeutic target for S. aureus-related infections and inflammatory diseases.

MiR-4653-3p and its target gene FRS2 are prognostic biomarkers for hormone receptor positive breast cancer patients receiving tamoxifen as adjuvant endocrine therapy

PubMed Central

Wang, Zhu; Wang, Yu; Wang, YanPing; Qiu, Yan; Li, Li; Bu, Hong; Li, JiaYuan; Zheng, Hong

2016-01-01

Long-term tamoxifen treatment significantly improves the survival of hormone receptor-positive (HR+) breast cancer (BC) patients. However, tamoxifen resistance remains a challenge. We aimed to identify prognostic biomarkers for tamoxifen resistance and reveal the underlying mechanism. From March 2001 to September 2013, 400 HR+ BC women (stage I~III) were treated with adjuvant tamoxifen for 5 years or until relapse in West China Hospital. We included a discovery set of 6 patients who were refractory to tamoxifen, and a validation cohort of 88 patients including 35 cases with relapse. In the discovery set, microRNA microarray showed that miR-4653-3p decreased in recurrent/metastatic lesions compared to the matched primary lesions. In the validation cohort, real-time RT-PCR demonstrated that, following tamoxifen treatment, miR-4653-3p overexpression in the primary tumors decreased the risk of relapse (adjusted hazard ratio [HR] = 0.17, 95% confidence interval [CI] = 0.05~0.57, P = 0.004). Conversely, high expression of FRS2, the key adaptor protein required by FGFR signaling, predicted poor disease-free survival (DFS) (adjusted HR = 2.70, 95% CI = 1.11~6.56, P = 0.03). MiR-4653-3p down regulated FRS2 by binding to its 3′ untranslated region. Either overexpressing miR-4653-3p or attenuating FRS2 expression could restore TAM sensitivity in two tamoxifen-resistant BC cell lines. In conclusion, high miR-4653-3p level was the potential predictor for favorable DFS, while FRS2 overexpression was potential high-risk factor for relapse in HR+ BC patients receiving TAM adjuvant therapy. FGFR/FRS2 signaling might be a promising target for reversing tamoxifen resistance. PMID:27533459

Alkaline Ceramidase 2 (ACER2) and Its Product Dihydrosphingosine Mediate the Cytotoxicity of N-(4-Hydroxyphenyl)retinamide in Tumor Cells*

PubMed Central

Mao, Zhehao; Sun, Wei; Xu, Ruijuan; Novgorodov, Sergei; Szulc, Zdzislaw M.; Bielawski, Jacek; Obeid, Lina M.; Mao, Cungui

2010-01-01

Increased generation of dihydrosphingosine (DHS), a bioactive sphingolipid, has been implicated in the cytotoxicity of the synthetic retinoid N-(4-hydroxyphenyl)retinamide (4-HPR) in tumor cells. However, how 4-HPR increases DHS remains unclear. Here we demonstrate that 4-HPR increases the expression of ACER2, which catalyzes the hydrolysis of dihydroceramides to generate DHS, and that ACER2 up-regulation plays a key role in mediating the 4-HPR-induced generation of DHS as well as the cytotoxicity of 4-HPR in tumor cells. Treatment with 4-HPR induced the accumulation of dihydroceramides (DHCs) in tumor cells by inhibiting dihydroceramide desaturase (DES) activity, which catalyzes the conversion of DHCs to ceramides. Treatment with 4-HPR also increased ACER2 expression through a retinoic acid receptor-independent and caspase-dependent manner. Overexpression of ACER2 augmented the 4-HPR-induced generation of DHS as well as 4-HPR cytotoxicity, and 4-HPR-induced death in tumor cells, whereas knocking down ACER2 had the opposite effects. ACER2 overexpression, along with treatment with GT11, another DES inhibitor, markedly increased cellular DHS, leading to tumor cell death, whereas ACER2 overexpression or GT11 treatment alone failed to do so, suggesting that both ACER2 up-regulation and DES inhibition are necessary and sufficient to mediate 4-HPR-induced DHS accumulation, cytotoxicity, and death in tumor cells. Taken together, these results suggest that up-regulation of the ACER2/DHS pathway mediates the cytotoxicity of 4-HPR in tumor cells and that up-regulating or activating ACER2 may improve the anti-cancer activity of 4-HRR and other DHC-inducing agents. PMID:20628055

DYRK1A is a novel negative regulator of cardiomyocyte hypertrophy.

PubMed

Kuhn, Christian; Frank, Derk; Will, Rainer; Jaschinski, Christoph; Frauen, Robert; Katus, Hugo A; Frey, Norbert

2009-06-19

Activation of the phosphatase calcineurin and its downstream targets, transcription factors of the NFAT family, results in cardiomyocyte hypertrophy. Recently, it has been shown that the dual specificity tyrosine (Y) phosphorylation-regulated kinase 1A (DYRK1A) is able to antagonize calcineurin signaling by directly phosphorylating NFATs. We thus hypothesized that DYRK1A might modulate the hypertrophic response of cardiomyocytes. In a model of phenylephrine-induced hypertrophy, adenovirus-mediated overexpression of DYKR1A completely abrogated the hypertrophic response and significantly reduced the expression of the natriuretic peptides ANF and BNP. Furthermore, DYRK1A blunted cardiomyocyte hypertrophy induced by overexpression of constitutively active calcineurin and attenuated the induction of the hypertrophic gene program. Conversely, knockdown of DYRK1A, utilizing adenoviruses encoding for a specific synthetic miRNA, resulted in an increase in cell surface area accompanied by up-regulation of ANF- mRNA. Similarly, treatment of cardiomyocytes with harmine, a specific inhibitor of DYRK1A, revealed cardiomyocyte hypertrophy on morphological and molecular level. Moreover, constitutively active calcineurin led to robust induction of an NFAT-dependent luciferase reporter, whereas DYRK1A attenuated calcineurin-induced reporter activation in cardiomyocytes. Conversely, both knockdown and pharmacological inhibition of DYRK1A significantly augmented the effect of calcineurin in this assay. In summary, we identified DYRK1A as a novel negative regulator of cardiomyocyte hypertrophy. Mechanistically, this effect appears to be mediated via inhibition of NFAT transcription factors.

DYRK1A Is a Novel Negative Regulator of Cardiomyocyte Hypertrophy*

PubMed Central

Kuhn, Christian; Frank, Derk; Will, Rainer; Jaschinski, Christoph; Frauen, Robert; Katus, Hugo A.; Frey, Norbert

2009-01-01

Activation of the phosphatase calcineurin and its downstream targets, transcription factors of the NFAT family, results in cardiomyocyte hypertrophy. Recently, it has been shown that the dual specificity tyrosine (Y) phosphorylation-regulated kinase 1A (DYRK1A) is able to antagonize calcineurin signaling by directly phosphorylating NFATs. We thus hypothesized that DYRK1A might modulate the hypertrophic response of cardiomyocytes. In a model of phenylephrine-induced hypertrophy, adenovirus-mediated overexpression of DYKR1A completely abrogated the hypertrophic response and significantly reduced the expression of the natriuretic peptides ANF and BNP. Furthermore, DYRK1A blunted cardiomyocyte hypertrophy induced by overexpression of constitutively active calcineurin and attenuated the induction of the hypertrophic gene program. Conversely, knockdown of DYRK1A, utilizing adenoviruses encoding for a specific synthetic miRNA, resulted in an increase in cell surface area accompanied by up-regulation of ANF- mRNA. Similarly, treatment of cardiomyocytes with harmine, a specific inhibitor of DYRK1A, revealed cardiomyocyte hypertrophy on morphological and molecular level. Moreover, constitutively active calcineurin led to robust induction of an NFAT-dependent luciferase reporter, whereas DYRK1A attenuated calcineurin-induced reporter activation in cardiomyocytes. Conversely, both knockdown and pharmacological inhibition of DYRK1A significantly augmented the effect of calcineurin in this assay. In summary, we identified DYRK1A as a novel negative regulator of cardiomyocyte hypertrophy. Mechanistically, this effect appears to be mediated via inhibition of NFAT transcription factors. PMID:19372220

Aloe-emodin inhibits HER-2 expression through the downregulation of Y-box binding protein-1 in HER-2-overexpressing human breast cancer cells.

PubMed

Ma, Jui-Wen; Hung, Chao-Ming; Lin, Ying-Chao; Ho, Chi-Tang; Kao, Jung-Yie; Way, Tzong-Der

2016-09-13

Human epidermal growth factor receptor-2 (HER-2)-positive breast cancer tends to be aggressive, highly metastatic, and drug resistant and spreads rapidly. Studies have indicated that emodin inhibits HER-2 expression. This study compared the HER-2-inhibitory effects of two compounds extracted from rhubarb roots: aloe-emodin (AE) and rhein. Our results indicated that AE exerted the most potent inhibitory effect on HER-2 expression. Treatment of HER-2-overexpressing breast cancer cells with AE reduced tumor initiation, cell migration, and cell invasion. AE was able to suppress YB-1 expression, further suppressing downstream HER-2 expression. AE suppressed YB-1 expression through the inhibition of Twist in HER-2-overexpressing breast cancer cells. Our data also found that AE inhibited cancer metastasis and cancer stem cells through the inhibition of EMT. Interestingly, AE suppressed YB-1 expression through the downregulation of the intracellular integrin-linked kinase (ILK)/protein kinase B (Akt)/mTOR signaling pathway in HER-2-overexpressing breast cancer cells. In vivo study showed the positive result of antitumor activity of AE in nude mice injected with human HER-2-overexpressing breast cancer cells. These findings suggest the possible application of AE in the treatment of HER-2-positive breast cancer.

Involvement of Phosphatidylinositol 3-Kinase-Mediated Up-Regulation of IκBα in Anti-Inflammatory Effect of Gemfibrozil in Microglia1

PubMed Central

Jana, Malabendu; Jana, Arundhati; Liu, Xiaojuan; Ghosh, Sankar; Pahan, Kalipada

2008-01-01

The present study underlines the importance of PI3K in mediating the anti-inflammatory effect of gemfibrozil, a prescribed lipid-lowering drug for humans, in mouse microglia. Gemfibrozil inhibited LPS-induced expression of inducible NO synthase (iNOS) and proinflammatory cytokines in mouse BV-2 microglial cells and primary microglia. By overexpressing wild-type and dominant-negative constructs of peroxisome proliferator-activated receptor-α (PPAR-α) in microglial cells and isolating primary microglia from PPAR-α−/− mice, we have demonstrated that gemfibrozil inhibits the activation of microglia independent of PPAR-α. Interestingly, gemfibrozil induced the activation of p85α-associated PI3K (p110β but not p110α) and inhibition of that PI3K by either chemical inhibitors or dominant-negative mutants abrogated the inhibitory effect of gemfibrozil. Conversely, overexpression of the constitutively active mutant of p110 enhanced the inhibitory effect of gemfibrozil on LPS-induced expression of proinflammatory molecules. Similarly, gemfibrozil also inhibited fibrillar amyloid β (Aβ)-, prion peptide (PrP)-, dsRNA (poly IC)-, HIV-1 Tat-, and 1-methyl-4-phenylpyridinium (MPP+)-, but not IFN-γ-, induced microglial expression of iNOS. Inhibition of PI3K also abolished the inhibitory effect of gemfibrozil on Aβ-, PrP-, poly IC-, Tat-, and MPP+-induced microglial expression of iNOS. Involvement of NF-κB activation in LPS-, Aβ-, PrP-, poly IC-, Tat-, and MPP+-, but not IFN-γ-, induced microglial expression of iNOS and stimulation of IκBα expression and inhibition of NF-κB activation by gemfibrozil via the PI3K pathway suggests that gemfibrozil inhibits the activation of NF-κB and the expression of proinflammatory molecules in microglia via PI3K-mediated up-regulation of IκBα. PMID:17785853

Secretory production of a beta-mannanase and a chitosanase using a Lactobacillus plantarum expression system.

PubMed

Sak-Ubol, Suttipong; Namvijitr, Peenida; Pechsrichuang, Phornsiri; Haltrich, Dietmar; Nguyen, Thu-Ha; Mathiesen, Geir; Eijsink, Vincent G H; Yamabhai, Montarop

2016-05-12

Heterologous production of hydrolytic enzymes is important for green and white biotechnology since these enzymes serve as efficient biocatalysts for the conversion of a wide variety of raw materials into value-added products. Lactic acid bacteria are interesting cell factories for the expression of hydrolytic enzymes as many of them are generally recognized as safe and require only a simple cultivation process. We are studying a potentially food-grade expression system for secretion of hydrolytic enzymes into the culture medium, since this enables easy harvesting and purification, while allowing direct use of the enzymes in food applications. We studied overexpression of a chitosanase (CsnA) and a β-mannanase (ManB), from Bacillus licheniformis and Bacillus subtilis, respectively, in Lactobacillus plantarum, using the pSIP system for inducible expression. The enzymes were over-expressed in three forms: without a signal peptide, with their natural signal peptide and with the well-known OmpA signal peptide from Escherichia coli. The total production levels and secretion efficiencies of CsnA and ManB were highest when using the native signal peptides, and both were reduced considerably when using the OmpA signal. At 20 h after induction with 12.5 ng/mL of inducing peptide in MRS media containing 20 g/L glucose, the yields and secretion efficiencies of the proteins with their native signal peptides were 50 kU/L and 84% for ManB, and 79 kU/L and 56% for CsnA, respectively. In addition, to avoid using antibiotics, the erythromycin resistance gene was replaced on the expression plasmid with the alanine racemase (alr) gene, which led to comparable levels of protein production and secretion efficiency in a suitable, alr-deficient L. plantarum host. ManB and CsnA were efficiently produced and secreted in L. plantarum using pSIP-based expression vectors containing either an erythromycin resistance or the alr gene as selection marker.

YY1 positively regulates human UBIAD1 expression

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

Funahashi, Nobuaki, E-mail: nfunahashi@ri.ncgm.go.jp; Department of Metabolic Disorder, Diabetes Research Center, Research Institute, National Center for Global Health and Medicine, Tokyo; Hirota, Yoshihisa

Vitamin K is involved in bone formation and blood coagulation. Natural vitamin K compounds are composed of the plant form phylloquinone (vitamin K{sub 1}) and a series of bacterial menaquionones (MK-n; vitamin K{sub 2}). Menadione (vitamin K{sub 3}) is an artificial vitamin K compound. MK-4 contains 4-isoprenyl as a side group in the 2-methyl-1,4-naphthoquinone common structure and has various bioactivities. UbiA prenyltransferase domain containing 1 (UBIAD1 or TERE1) is the menaquinone-4 biosynthetic enzyme. UBIAD1 transcript expression significantly decreases in patients with prostate carcinoma and overexpressing UBIAD1 inhibits proliferation of a tumour cell line. UBIAD1 mRNA expression is ubiquitous in mousemore » tissues, and higher UBIAD1 mRNA expression levels are detected in the brain, heart, kidneys and pancreas. Several functions of UBIAD1 have been reported; however, regulation of the human UBIAD1 gene has not been elucidated. Here we report cloning and characterisation of the human UBIAD1 promoter. A 5′ rapid amplification of cDNA ends analysis revealed that the main transcriptional start site was 306 nucleotides upstream of the translation initiation codon. Deletion and mutation analyses revealed the functional importance of the YY1 consensus motif. Electrophoretic gel mobility shift and chromatin immunoprecipitation assays demonstrated that YY1 binds the UBIAD1 promoter in vitro and in vivo. In addition, YY1 small interfering RNA decreased endogenous UBIAD1 mRNA expression and UBIAD1 conversion activity. These results suggest that YY1 up-regulates UBIAD1 expression and UBIAD1 conversion activity through the UBIAD1 promoter. - Highlights: • We cloned the human UBIAD1 promoter. • The functional importance of the YY1 motif was identified in the UBIAD1 promoter. • YY1 binds the UBIAD1 promoter in vitro and in vivo. • Knockdown of YY1 significantly decreased UBIAD1 expression. • YY1 up-regulates UBIAD1 conversion activity through the UBIAD1 promoter.« less

TWEAK Appears as a Modulator of Endometrial IL-18 Related Cytotoxic Activity of Uterine Natural Killers

PubMed Central

Petitbarat, Marie; Rahmati, Mona; Sérazin, Valérie; Dubanchet, Sylvie; Morvan, Corinne; Wainer, Robert; de Mazancourt, Philippe; Chaouat, Gérard; Foidart, Jean-Michel; Munaut, Carine; Lédée, Nathalie

2011-01-01

Background TWEAK (Tumor necrosis factor like WEAK inducer of apoptosis) is highly expressed by different immune cells and triggers multiple cellular responses, including control of angiogenesis. Our objective was to investigate its role in the human endometrium during the implantation window, using an ex-vivo endometrial microhistoculture model. Indeed, previous results suggested that basic TWEAK expression influences the IL-18 related uNK recruitment and local cytotoxicity. Methodology/Principal Findings Endometrial biopsies were performed 7 to 9 days after the ovulation surge of women in monitored natural cycles. Biopsies were cut in micro-pieces and cultured on collagen sponge with appropriate medium. Morphology, functionality and cell death were analysed at different time of the culture. We used this ex vivo model to study mRNA expressions of NKp46 (a uNK cytotoxic receptor) and TGF-beta1 (protein which regulates uNK cytokine production) after adjunction of excess of recombinant IL-18 and either recombinant TWEAK or its antibody. NKp46 protein expression was also detailed by immunohistochemistry in selected patients with high basic mRNA level of IL-18 and either low or high mRNA level of TWEAK. The NKp46 immunostaining was stronger in patients with an IL-18 over-expression and a low TWEAK expression, when compared with patients with both IL-18 and TWEAK high expressions. We did not observe any difference for TWEAK expression when recombinant protein IL-18 or its antibody was added, or conversely, for IL-18 expression when TWEAK or its antibody was added in the culture medium. In a pro-inflammatory environment (obtained by an excess of IL-18), inhibition of TWEAK was able to increase significantly NKp46 and TGF-beta1 mRNA expressions. Conclusions/Significance TWEAK doesn't act on IL-18 expression but seems to control IL-18 related cytotoxicity on uNK cells when IL-18 is over-expressed. Thus, TWEAK appears as a crucial physiological modulator to prevent endometrial uNK cytotoxicity in human. PMID:21249128

Aurora-A over-expression in high-grade PIN lesions and prostate cancer.

PubMed

Buschhorn, Holly McKlveen; Klein, Robert R; Chambers, Susan M; Hardy, Margaret C; Green, Sylvan; Bearss, David; Nagle, Raymond B

2005-09-01

Over-expression of Aurora-A (Aurora 2 kinase, STK-15), a protein found in centrosomes thought to be associated with genetic instability, has been previously documented in prostate cancer [Pihan et al.: Cancer Res 61(5):2212-2219, 2001]. It is unknown if this protein is also over-expressed in high-grade prostatic intraepithelial neoplasia (PIN) lesions. PIN lesions were examined for increased Aurora-A using immunohistochemical staining on archival paraffin embedded prostatectomy tissue. Aurora-A expression was scored using size, number, and staining intensity. Protein expression was examined and compared between stromal cells, normal glands, high-grade PIN lesions, and invasive cancer. Immunohistochemistry shows an increased expression of Aurora-A in 96% of high-grade PIN cases, and 98% in cancer lesions. Twenty-nine percent of cases of normal glands from cancerous prostates also showed increased Aurora-A expression. Over-expression of Aurora-A is present in some normal and the majority of high-grade PIN lesions indicating that this may be an early event that leads to the genetic instability seen in prostate carcinogenesis. Copyright 2005 Wiley-Liss, Inc.

[Over-expressed Bax inhibitor 1 (BI-1) inhibits apoptosis of hippocampal neurons via endoplasmic reticulum IRE1-JNK pathway in rats with subarachnoid hemorrhage].

PubMed

Liu, Jiaxin; Zhou, Shuai; Qian, Xiying; Zhang, Yueting; Zhao, Jianhua

2017-10-01

Objective To investigate the protective effect of lentivirus-mediated BI-1 overexpression on hippocampal neurons in rats with subarachnoid hemorrhage (SAH) and the relationship with endoplasmic reticulum IRE1-JNK signaling pathway. Methods The lentivirus solution of BI-1 over-expression was injected into the brain of rats 24 hours before SAH rat model was established by intravascular puncture method. At 24 hours after modeling, the brain water content and neurological score of the rats were measured. The apoptosis of hippocampal neurons was detected by TUNEL assay. Western blotting was used to detect the expressions of BI-1 protein and endoplasmic reticulum stress (ERS) marker proteins GRP78 and IRE1. ERS in hippocampal neurons of the rats with SAH was intervened by IRE1α-specific inhibitor KIRA6, and then the protein expressions of p-IRE1, p-JNK, Bax, Bcl2 and caspase-3 were detected by Western blotting. Results BI-1 over-expression improved neurobehavioral score, decreased brain water content and hippocampal neuron apoptosis rate, and also down-regulated GRP78 and IRE1 protein levels in the rats with SAH. Both the interference of KIRA6 and the over-expression of BI-1 inhibited the expressions of p-IRE1, p-JNK, Bax and caspase-3, and promoted the expression of anti-apoptotic protein Bcl2. Conclusion Over-expression of BI-1 can inhibit the apoptosis of hippocampal neurons in rats with SAH by inhibiting the activation of ERS-mediated IRE1-JNK signaling pathway, thus ultimately attenuating the early brain injury following SAH.

GroEL-GroES assisted folding of multiple recombinant proteins simultaneously over-expressed in Escherichia coli.

PubMed

Goyal, Megha; Chaudhuri, Tapan K

2015-07-01

Folding of aggregation prone recombinant proteins through co-expression of chaperonin GroEL and GroES has been a popular practice in the effort to optimize preparation of functional protein in Escherichia coli. Considering the demand for functional recombinant protein products, it is desirable to apply the chaperone assisted protein folding strategy for enhancing the yield of properly folded protein. Toward the same direction, it is also worth attempting folding of multiple recombinant proteins simultaneously over-expressed in E. coli through the assistance of co-expressed GroEL-ES. The genesis of this thinking was originated from the fact that cellular GroEL and GroES assist in the folding of several endogenous proteins expressed in the bacterial cell. Here we present the experimental findings from our study on co-expressed GroEL-GroES assisted folding of simultaneously over-expressed proteins maltodextrin glucosidase (MalZ) and yeast mitochondrial aconitase (mAco). Both proteins mentioned here are relatively larger and aggregation prone, mostly form inclusion bodies, and undergo GroEL-ES assisted folding in E. coli cells during over-expression. It has been reported that the relative yield of properly folded functional forms of MalZ and mAco with the exogenous GroEL-ES assistance were comparable with the results when these proteins were overexpressed alone. This observation is quite promising and highlights the fact that GroEL and GroES can assist in the folding of multiple substrate proteins simultaneously when over-expressed in E. coli. This method might be a potential tool for enhanced production of multiple functional recombinant proteins simultaneously in E. coli. Copyright © 2015 Elsevier Ltd. All rights reserved.

Overexpressing of OsAMT1-3, a High Affinity Ammonium Transporter Gene, Modifies Rice Growth and Carbon-Nitrogen Metabolic Status

PubMed Central

Bao, Aili; Liang, Zhijun; Zhao, Zhuqing; Cai, Hongmei

2015-01-01

AMT1-3 encodes the high affinity NH4+ transporter in rice roots and is predominantly expressed under nitrogen starvation. In order to evaluate the effect of AMT1-3 gene on rice growth, nitrogen absorption and metabolism, we generated AMT1-3-overexpressing plants and analyzed the growth phenotype, yield, carbon and nitrogen metabolic status, and gene expression profiles. Although AMT1-3 mRNA accumulated in transgenic plants, these plants displayed significant decreases in growth when compared to the wild-type plants. The nitrogen uptake assay using a 15N tracer revealed poor nitrogen uptake ability in AMT1-3-overexpressing plants. We found significant decreases in AMT1-3-overexpressing plant leaf carbon and nitrogen content accompanied with a higher leaf C/N ratio. Significant changes in soluble proteins and carbohydrates were also observed in AMT1-3-overexpressing plants. In addition, metabolite profile analysis demonstrated significant changes in individual sugars, organic acids and free amino acids. Gene expression analysis revealed distinct expression patterns of genes that participate in carbon and nitrogen metabolism. Additionally, the correlation between the metabolites and gene expression patterns was consistent in AMT1-3-overexpressing plants under both low and high nitrogen growth conditions. Therefore, we hypothesized that the carbon and nitrogen metabolic imbalance caused by AMT1-3 overexpressing attributed to the poor growth and yield of transgenic plants. PMID:25915023

D-Tagatose production in the presence of borate by resting Lactococcus lactis cells harboring Bifidobacterium longum L-arabinose isomerase.

PubMed

Salonen, Noora; Salonen, Kalle; Leisola, Matti; Nyyssölä, Antti

2013-04-01

Bifidobacterium longum NRRL B-41409 L-arabinose isomerase (L-AI) was overexpressed in Lactococcus lactis using a phosphate depletion inducible expression system. The resting L. lactis cells harboring the B. longum L-AI were used for production of D-tagatose from D-galactose in the presence of borate buffer. Multivariable analysis suggested that high pH, temperature and borate concentration favoured the conversion of D-galactose to D-tagatose. Almost quantitative conversion (92 %) was achieved at 20 g L⁻¹ substrate and at 37.5 °C after 5 days. The D-tagatose production rate of 185 g L⁻¹ day ⁻¹ was obtained at 300 g L⁻¹ galactose, at 1.15 M borate, and at 41 °C during 10 days when the production medium was changed every 24 h. There was no significant loss in productivity during ten sequential 24 h batches. The initial D-tagatose production rate was 290 g L⁻¹ day⁻¹ under these conditions.

Fatty Aldehydes in Cyanobacteria Are a Metabolically Flexible Precursor for a Diversity of Biofuel Products

PubMed Central

Kaiser, Brett K.; Carleton, Michael; Hickman, Jason W.; Miller, Cameron; Lawson, David; Budde, Mark; Warrener, Paul; Paredes, Angel; Mullapudi, Srinivas; Navarro, Patricia; Cross, Fred; Roberts, James M.

2013-01-01

We describe how pathway engineering can be used to convert a single intermediate derived from lipid biosynthesis, fatty aldehydes, into a variety of biofuel precursors including alkanes, free fatty acids and wax esters. In cyanobacteria, long-chain acyl-ACPs can be reduced to fatty aldehydes, and then decarbonylated to alkanes. We discovered a cyanobacteria class-3 aldehyde-dehydrogenase, AldE, that was necessary and sufficient to instead oxidize fatty aldehyde precursors into fatty acids. Overexpression of enzymes in this pathway resulted in production of 50 to 100 fold more fatty acids than alkanes, and the fatty acids were secreted from the cell. Co-expression of acyl-ACP reductase, an alcohol-dehydrogenase and a wax-ester-synthase resulted in a third fate for fatty aldehydes: conversion to wax esters, which accumulated as intracellular lipid bodies. Conversion of acyl-ACP to fatty acids using endogenous cyanobacterial enzymes may allow biofuel production without transgenesis. PMID:23505484

C/EBPβ regulates delta-secretase expression and mediates pathogenesis in mouse models of Alzheimer's disease.

PubMed

Wang, Zhi-Hao; Gong, Ke; Liu, Xia; Zhang, Zhentao; Sun, Xiaoou; Wei, Zheng Zachory; Yu, Shan Ping; Manfredsson, Fredric P; Sandoval, Ivette M; Johnson, Peter F; Jia, Jianping; Wang, Jian-Zhi; Ye, Keqiang

2018-05-03

Delta-secretase cleaves both APP and Tau to mediate the formation of amyloid plaques and neurofibrillary tangle in Alzheimer's disease (AD). However, how aging contributes to an increase in delta-secretase expression and AD pathologies remains unclear. Here we show that a CCAAT-enhancer-binding protein (C/EBPβ), an inflammation-regulated transcription factor, acts as a key age-dependent effector elevating both delta-secretase (AEP) and inflammatory cytokines expression in mediating pathogenesis in AD mouse models. We find that C/EBPβ regulates delta-secretase transcription and protein levels in an age-dependent manner. Overexpression of C/EBPβ in young 3xTg mice increases delta-secretase and accelerates the pathological features including cognitive dysfunctions, which is abolished by inactive AEP C189S. Conversely, depletion of C/EBPβ from old 3xTg or 5XFAD mice diminishes delta-secretase and reduces AD pathologies, leading to amelioration of cognitive impairment in these AD mouse models. Thus, our findings support that C/EBPβ plays a pivotal role in AD pathogenesis via increasing delta-secretase expression.

miR-188 promotes senescence of lineage-negative bone marrow cells by targeting MAP3K3 expression.

PubMed

Zheng, Yue; Liu, Hua; Kong, Ye

2017-08-01

Lineage-negative bone marrow cells (lin-BMCs) have reparative potential for overcoming endothelial dysfunction and reducing cardiovascular risk. Here, we found that miR-188 is upregulated and mitogen-activated protein kinase kinase kinase 3 (MAP3K3) is downregulated in aged lin-BMCs, whereas their expression is reversed in young lin-BMCs. We identified and confirmed MAP3K3 as a direct target of miR-188. MiR-188 overexpression or MAP3K3 silencing in young lin-BMCs increases p16 and p21 expression, enhances cell senescence, and decreases the ability for cell proliferation, migration, and tube formation. Conversely, miR-188 suppression in aged lin-BMCs yields the opposite results. We further found that MAP3K3 is involved in miR-188-induced promotion of lin-BMC senescence. All data reveal that miR-188 induces lin-BMC senescence by targeting MAP3K3 expression, thus, providing new theoretical basis for the prevention and treatment of cardiovascular diseases. © 2017 Federation of European Biochemical Societies.

SLP-2 overexpression could serve as a prognostic factor in node positive and HER2 negative breast cancer.

PubMed

Cao, Wenfeng; Zhang, Bin; Li, Jin; Liu, Yanxue; Liu, Zhihua; Sun, Baocun

2011-12-01

This study aimed to evaluate the utility as a prognostic factor of SLP-2 on the outcome of breast cancer patients. We performed immunohistochemical analysis to examine the SLP-2 expression in a large panel of invasive breast cancer samples. Of the 496 samples, 261 showed overexpression of SLP-2. Importantly, there were significant associations between SLP-2 overexpression and tumour size (p = 0.002), lymph node/distant metastases, clinical stage (p < 0.001), HER2/neu expression (p = 0.003). In addition, there were obvious differences in levels of SLP-2 expression within four molecular subtypes of breast cancer (p = 0.011). High level SLP-2 expression was shown in tumour samples of HER2 and luminal B subtypes, and low level SLP-2 expression was shown in luminal A and triple negative subtypes, suggesting that overexpression of SLP-2 was closely correlated with HER2/neu expression, and that both SLP-2 and HER2/neu can play a role in lymph node/distant metastases of breast cancers. Thus lymph node status, HER2/neu and SLP-2 high-level expression can act as independent prognostic factors. There is an obvious link between SLP-2 and HER2/neu expression. Overexpression of SLP-2 is associated with poorer total survival, especially in lymph node positive coupled with HER2/neu negative patients.

Asymmetric inhibition of Ulk2 causes left-right differences in habenular neuropil formation.

PubMed

Taylor, Robert W; Qi, Jenny Y; Talaga, Anna K; Ma, Taylur P; Pan, Luyuan; Bartholomew, Clinton R; Klionsky, Daniel J; Moens, Cecilia B; Gamse, Joshua T

2011-07-06

Studies of the zebrafish epithalamus have provided recent insights into the development of left-right brain asymmetry, which is crucial to normal human brain function. The habenular nuclei of zebrafish are robustly asymmetric, with dense elaboration of neuropil only in the left lateral subnucleus. Because this feature is tightly correlated with asymmetric expression of K(+) channel tetramerization domain-containing proteins 12.1 and 12.2 (Kctd12.1/12.2), we screened for Kctd12.1-interacting proteins to identify molecular mechanisms leading to neuropil asymmetry, and uncovered a novel interaction between Kctd12.1 and Unc-51-like kinase 2 (Ulk2). We show here that knockdown of Ulk2 or overexpression of Kctd12 proteins reduces asymmetric neuropil elaboration. Conversely, overexpression of Ulk2 or mutation of kctd12 genes causes excess neuropil elaboration. We conclude that Ulk2 activity promotes neuropil elaboration while Kctd12 proteins limit Ulk2 activity asymmetrically. This work describes a regulatory mechanism for neuronal process extension that may be conserved in other developmental contexts in addition to the epithalamus.

Genomic amplification of Fanconi anemia complementation group A (FancA) in head and neck squamous cell carcinoma (HNSCC): Cellular mechanisms of radioresistance and clinical relevance.

PubMed

Hess, Julia; Unger, Kristian; Orth, Michael; Schötz, Ulrike; Schüttrumpf, Lars; Zangen, Verena; Gimenez-Aznar, Igor; Michna, Agata; Schneider, Ludmila; Stamp, Ramona; Selmansberger, Martin; Braselmann, Herbert; Hieber, Ludwig; Drexler, Guido A; Kuger, Sebastian; Klein, Diana; Jendrossek, Verena; Friedl, Anna A; Belka, Claus; Zitzelsberger, Horst; Lauber, Kirsten

2017-02-01

Radio (chemo) therapy is a crucial treatment modality for head and neck squamous cell carcinoma (HNSCC), but relapse is frequent, and the underlying mechanisms remain largely elusive. Therefore, novel biomarkers are urgently needed. Previously, we identified gains on 16q23-24 to be associated with amplification of the Fanconi anemia A (FancA) gene and to correlate with reduced progression-free survival after radiotherapy. Here, we analyzed the effects of FancA on radiation sensitivity in vitro, characterized the underlying mechanisms, and evaluated their clinical relevance. Silencing of FancA expression in HNSCC cell lines with genomic gains on 16q23-24 resulted in significantly impaired clonogenic survival upon irradiation. Conversely, overexpression of FancA in immortalized keratinocytes conferred increased survival accompanied by improved DNA repair, reduced accumulation of chromosomal translocations, but no hyperactivation of the FA/BRCA-pathway. Downregulation of interferon signaling as identified by microarray analyses, enforced irradiation-induced senescence, and elevated production of the senescence-associated secretory phenotype (SASP) appeared to be candidate mechanisms contributing to FancA-mediated radioresistance. Data of the TCGA HNSCC cohort confirmed the association of gains on 16q24.3 with FancA overexpression and impaired overall survival. Importantly, transcriptomic alterations similar to those observed upon FancA overexpression in vitro strengthened the clinical relevance. Overall, FancA amplification and overexpression appear to be crucial for radiotherapeutic failure in HNSCC. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

FOXP3 over-expression inhibits melanoma tumorigenesis via effects on proliferation and apoptosis.

PubMed Central

Tan, BeeShin; Anaka, Matthew; Deb, Siddhartha; Freyer, Claudia; Ebert, Lisa M.; Chueh, Anderly C.; Al-Obaidi, Sheren; Behren, Andreas; Jayachandran, Aparna; Cebon, Jonathan; Chen, Weisan; Mariadason, John M.

2014-01-01

The Forkhead box P3 (FOXP3) transcription factor is the key driver of regulatory T cell (Treg cells) differentiation and immunosuppressive function. In addition, FOXP3 has been reported to be expressed in many tumors, including melanoma. However, its role in tumorigenesis is conficting, with both tumor suppressive and tumor promoting functions described. The aim of the current study was to characterize the expression and function of FOXP3 in melanoma. FOXP3 expression was detected by immunohistochemistry (IHC) in 12% (18/146) of stage III and IV melanomas. However expression was confined to fewer than 1% of cells in these tumors. Stable over-expression of FOXP3 in the SK-MEL-28 melanoma cell line reduced cell proliferation and clonogenicity in vitro, and reduced xenograft growth in vivo. FOXP3 over-expression also increased pigmentation and the rate of apoptosis of SK-MEL-28 cells. Based on its infrequent expression in human melanoma, and its growth inhibitory and pro-apoptotic effect in over-expressing melanoma cells, we conclude that FOXP3 is not likely to be a key tumor suppressor or promoter in melanoma. PMID:24406338

Transcriptional Regulation of S Phase Kinase-associated Protein 2 by NR4A Orphan Nuclear Receptor NOR1 in Vascular Smooth Muscle Cells*

PubMed Central

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

2011-01-01

Members of the NR4A subgroup of the nuclear hormone receptor superfamily have emerged as key transcriptional regulators of proliferation and inflammation. NOR1 constitutes a ligand-independent transcription factor of this subgroup and induces cell proliferation; however, the transcriptional mechanisms underlying this mitogenic role remain to be defined. Here, we demonstrate that the F-box protein SKP2 (S phase kinase-associated protein 2), the substrate-specific receptor of the ubiquitin ligase responsible for the degradation of p27KIP1 through the proteasome pathway, constitutes a direct transcriptional target for NOR1. Mitogen-induced Skp2 expression is silenced in vascular smooth muscle cells (VSMC) isolated from Nor1-deficient mice or transfected with Nor1 siRNA. Conversely, adenovirus-mediated overexpression of NOR1 induces Skp2 expression in VSMC and decreases protein abundance of its target p27. Transient transfection experiments establish that NOR1 transactivates the Skp2 promoter through a nerve growth factor-induced clone B response element (NBRE). Electrophoretic mobility shift and chromatin immunoprecipitation assays further revealed that NOR1 is recruited to this NBRE site in the Skp2 promoter in response to mitogenic stimulation. In vivo Skp2 expression is increased during the proliferative response underlying neointima formation, and this transcriptional induction depends on the expression of NOR1. Finally, we demonstrate that overexpression of Skp2 rescues the proliferative arrest of Nor1-deficient VSMC. Collectively, these results characterize Skp2 as a novel NOR1-regulated target gene and detail a previously unrecognized transcriptional cascade regulating mitogen-induced VSMC proliferation. PMID:21868379

Perilipin 1 Mediates Lipid Metabolism Homeostasis and Inhibits Inflammatory Cytokine Synthesis in Bovine Adipocytes

PubMed Central

Zhang, Shiqi; Liu, Guowen; Xu, Chuang; Liu, Lei; Zhang, Qiang; Xu, Qiushi; Jia, Hongdou; Li, Xiaobing; Li, Xinwei

2018-01-01

Dairy cows with ketosis displayed lipid metabolic disorder and high inflammatory levels. Adipose tissue is an active lipid metabolism and endocrine tissue and is closely related to lipid metabolism homeostasis and inflammation. Perilipin 1 (PLIN1), an adipocyte-specific lipid-coated protein, may be involved in the above physiological function. The aim of this study is to investigate the role of PLIN1 in lipid metabolism regulation and inflammatory factor synthesis in cow adipocytes. The results showed that PLIN1 overexpression upregulated the expression of fatty acid and triglyceride (TAG) synthesis molecule sterol regulator element-binding protein-1c (SREBP-1c) and its target genes, diacylglycerol acyltransferase (DGAT) 1, and DGAT2, but inhibited the expression of lipolysis enzymes hormone-sensitive lipase (HSL) and CGI-58 for adipose triglyceride lipase (ATGL), thus augmenting the fatty acids and TAG synthesis and inhibiting lipolysis. Importantly, PLIN1 overexpression inhibited the activation of the NF-κB inflammatory pathway and decreased the expression and content of tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6) induced by lipopolysaccharide. Conversely, PLIN1 silencing inhibited TAG synthesis, promoted lipolysis, and overinduced the activation of the NF-κB inflammatory pathway in cow adipocytes. In ketotic cows, the expression of PLIN1 was markedly decreased, whereas lipid mobilization, NF-κB pathway, and downstream inflammatory cytokines were overinduced in adipose tissue. Taken together, these results indicate that PLIN1 can maintain lipid metabolism homeostasis and inhibit the NF-κB inflammatory pathway in adipocytes. However, low levels of PLIN1 reduced the inhibitory effect on fat mobilization, NF-κB pathway, and inflammatory cytokine synthesis in ketotic cows. PMID:29593725

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

PubMed

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

2000-11-01

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

Markedly Increased Susceptibility to Natural Sheep Scrapie of Transgenic Mice Expressing Ovine PrP

PubMed Central

Vilotte, Jean-Luc; Soulier, Solange; Essalmani, Rachid; Stinnakre, Marie-George; Vaiman, Daniel; Lepourry, Laurence; Da Silva, Jose Costa; Besnard, Nathalie; Dawson, Mike; Buschmann, Anne; Groschup, Martin; Petit, Stephanie; Madelaine, Marie-Francoise; Rakatobe, Sabine; Le Dur, Annick; Vilette, Didier; Laude, Hubert

2001-01-01

The susceptibility of sheep to scrapie is known to involve, as a major determinant, the nature of the prion protein (PrP) allele, with the VRQ allele conferring the highest susceptibility to the disease. Transgenic mice expressing in their brains three different ovine PrPVRQ-encoding transgenes under an endogenous PrP-deficient genetic background were established. Nine transgenic (tgOv) lines were selected and challenged with two scrapie field isolates derived from VRQ-homozygous affected sheep. All inoculated mice developed neurological signs associated with a transmissible spongiform encephalopathy (TSE) disease and accumulated a protease-resistant form of PrP (PrPres) in their brains. The incubation duration appeared to be inversely related to the PrP steady-state level in the brain, irrespective of the transgene construct. The survival time for animals from the line expressing the highest level of PrP was reduced by at least 1 year compared to those of two groups of conventional mice. With one isolate, the duration of incubation was as short as 2 months, which is comparable to that observed for the rodent TSE models with the briefest survival times. No survival time reduction was observed upon subpassaging of either isolate, suggesting no need for adaptation of the agent to its new host. Overexpression of the transgene was found not to be required for transmission to be accelerated compared to that observed with wild-type mice. Conversely, transgenic mice overexpressing murine PrP were found to be less susceptible than tgOv lines expressing ovine PrP at physiological levels. These data argue that ovine PrPVRQ provided a better substrate for sheep prion replication than did mouse PrP. Altogether, these tgOv mice could be an improved model for experimental studies on natural sheep scrapie. PMID:11390599

RAD18 mediates resistance to ionizing radiation in human glioma cells

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

Xie, Chen; Wang, Hongwei; Cheng, Hongbin

Highlights: • RAD18 is an important mediator of the IR-induced resistance in glioma cell lines. • RAD18 overexpression confers resistance to IR-mediated apoptosis. • The elevated expression of RAD18 is associated with recurrent GBM who underwent IR therapy. - Abstract: Radioresistance remains a major challenge in the treatment of glioblastoma multiforme (GBM). RAD18 a central regulator of translesion DNA synthesis (TLS), has been shown to play an important role in regulating genomic stability and DNA damage response. In the present study, we investigate the relationship between RAD18 and resistance to ionizing radiation (IR) and examined the expression levels of RAD18more » in primary and recurrent GBM specimens. Our results showed that RAD18 is an important mediator of the IR-induced resistance in GBM. The expression level of RAD18 in glioma cells correlates with their resistance to IR. Ectopic expression of RAD18 in RAD18-low A172 glioma cells confers significant resistance to IR treatment. Conversely, depletion of endogenous RAD18 in RAD18-high glioma cells sensitized these cells to IR treatment. Moreover, RAD18 overexpression confers resistance to IR-mediated apoptosis in RAD18-low A172 glioma cells, whereas cells deficient in RAD18 exhibit increased apoptosis induced by IR. Furthermore, knockdown of RAD18 in RAD18-high glioma cells disrupts HR-mediated repair, resulting in increased accumulation of DSB. In addition, clinical data indicated that RAD18 was significantly higher in recurrent GBM samples that were exposed to IR compared with the corresponding primary GBM samples. Collectively, our findings reveal that RAD18 may serve as a key mediator of the IR response and may function as a potential target for circumventing IR resistance in human GBM.« less

Perilipin 1 Mediates Lipid Metabolism Homeostasis and Inhibits Inflammatory Cytokine Synthesis in Bovine Adipocytes.

PubMed

Zhang, Shiqi; Liu, Guowen; Xu, Chuang; Liu, Lei; Zhang, Qiang; Xu, Qiushi; Jia, Hongdou; Li, Xiaobing; Li, Xinwei

2018-01-01

Dairy cows with ketosis displayed lipid metabolic disorder and high inflammatory levels. Adipose tissue is an active lipid metabolism and endocrine tissue and is closely related to lipid metabolism homeostasis and inflammation. Perilipin 1 (PLIN1), an adipocyte-specific lipid-coated protein, may be involved in the above physiological function. The aim of this study is to investigate the role of PLIN1 in lipid metabolism regulation and inflammatory factor synthesis in cow adipocytes. The results showed that PLIN1 overexpression upregulated the expression of fatty acid and triglyceride (TAG) synthesis molecule sterol regulator element-binding protein-1c (SREBP-1c) and its target genes, diacylglycerol acyltransferase (DGAT) 1, and DGAT2, but inhibited the expression of lipolysis enzymes hormone-sensitive lipase (HSL) and CGI-58 for adipose triglyceride lipase (ATGL), thus augmenting the fatty acids and TAG synthesis and inhibiting lipolysis. Importantly, PLIN1 overexpression inhibited the activation of the NF-κB inflammatory pathway and decreased the expression and content of tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6) induced by lipopolysaccharide. Conversely, PLIN1 silencing inhibited TAG synthesis, promoted lipolysis, and overinduced the activation of the NF-κB inflammatory pathway in cow adipocytes. In ketotic cows, the expression of PLIN1 was markedly decreased, whereas lipid mobilization, NF-κB pathway, and downstream inflammatory cytokines were overinduced in adipose tissue. Taken together, these results indicate that PLIN1 can maintain lipid metabolism homeostasis and inhibit the NF-κB inflammatory pathway in adipocytes. However, low levels of PLIN1 reduced the inhibitory effect on fat mobilization, NF-κB pathway, and inflammatory cytokine synthesis in ketotic cows.

Notch3 Maintains Luminal Phenotype and Suppresses Tumorigenesis and Metastasis of Breast Cancer via Trans-Activating Estrogen Receptor-α.

PubMed

Dou, Xiao-Wei; Liang, Yuan-Ke; Lin, Hao-Yu; Wei, Xiao-Long; Zhang, Yong-Qu; Bai, Jing-Wen; Chen, Chun-Fa; Chen, Min; Du, Cai-Wen; Li, Yao-Chen; Tian, Jie; Man, Kwan; Zhang, Guo-Jun

2017-01-01

The luminal A phenotype is the most common breast cancer subtype and is characterized by estrogen receptor α expression (ERα). Identification of the key regulator that governs the luminal phenotype of breast cancer will clarify the pathogenic mechanism and provide novel therapeutic strategies for this subtype of cancer. ERα signaling pathway sustains the epithelial phenotype and inhibits the epithelial-mesenchymal transition (EMT) of breast cancer. In this study, we demonstrate that Notch3 positively associates with ERα in both breast cancer cell lines and human breast cancer tissues. We found that overexpression of Notch3 intra-cellular domain, a Notch3 active form (N3ICD), in ERα negative breast cancer cells re-activated ERα, while knock-down of Notch3 reduced ERα transcript and proteins, with alteration of down-stream genes, suggesting its ability to regulate ERα. Mechanistically, our results show that Notch3 specifically binds to the CSL binding element of the ERα promoter and activates ERα expression. Moreover, Notch3 suppressed EMT, while suppression of Notch3 promoted EMT in cellular assay. Overexpressing N3ICD in triple-negative breast cancer suppressed tumorigenesis and metastasis in vivo . Conversely, depletion of Notch3 in luminal breast cancer promoted metastasis in vivo . Furthermore, Notch3 transcripts were significantly associated with prolonged relapse-free survival in breast cancer, in particular in ERα positive breast cancer patients. Our observations demonstrate that Notch3 governs the luminal phenotype via trans-activating ERα expression in breast cancer. These findings delineate the role of a Notch3/ERα axis in maintaining the luminal phenotype and inhibiting tumorigenesis and metastasis in breast cancer, providing a novel strategy to re-sensitize ERα negative or low-expressing breast cancers to hormone therapy.

Notch3 Maintains Luminal Phenotype and Suppresses Tumorigenesis and Metastasis of Breast Cancer via Trans-Activating Estrogen Receptor-α

PubMed Central

Dou, Xiao-Wei; Liang, Yuan-Ke; Lin, Hao-Yu; Wei, Xiao-Long; Zhang, Yong-Qu; Bai, Jing-Wen; Chen, Chun-Fa; Chen, Min; Du, Cai-Wen; Li, Yao-Chen; Tian, Jie; Man, Kwan; Zhang, Guo-Jun

2017-01-01

The luminal A phenotype is the most common breast cancer subtype and is characterized by estrogen receptor α expression (ERα). Identification of the key regulator that governs the luminal phenotype of breast cancer will clarify the pathogenic mechanism and provide novel therapeutic strategies for this subtype of cancer. ERα signaling pathway sustains the epithelial phenotype and inhibits the epithelial-mesenchymal transition (EMT) of breast cancer. In this study, we demonstrate that Notch3 positively associates with ERα in both breast cancer cell lines and human breast cancer tissues. We found that overexpression of Notch3 intra-cellular domain, a Notch3 active form (N3ICD), in ERα negative breast cancer cells re-activated ERα, while knock-down of Notch3 reduced ERα transcript and proteins, with alteration of down-stream genes, suggesting its ability to regulate ERα. Mechanistically, our results show that Notch3 specifically binds to the CSL binding element of the ERα promoter and activates ERα expression. Moreover, Notch3 suppressed EMT, while suppression of Notch3 promoted EMT in cellular assay. Overexpressing N3ICD in triple-negative breast cancer suppressed tumorigenesis and metastasis in vivo. Conversely, depletion of Notch3 in luminal breast cancer promoted metastasis in vivo. Furthermore, Notch3 transcripts were significantly associated with prolonged relapse-free survival in breast cancer, in particular in ERα positive breast cancer patients. Our observations demonstrate that Notch3 governs the luminal phenotype via trans-activating ERα expression in breast cancer. These findings delineate the role of a Notch3/ERα axis in maintaining the luminal phenotype and inhibiting tumorigenesis and metastasis in breast cancer, providing a novel strategy to re-sensitize ERα negative or low-expressing breast cancers to hormone therapy. PMID:29109797

Galectin-1 mediates TGF-β-induced transformation from normal fibroblasts into carcinoma-associated fibroblasts and promotes tumor progression in gastric cancer

PubMed Central

Zheng, Lingyan; Xu, Cong; Guan, Zhonghai; Su, Xingyun; Xu, Zhenzhen; Cao, Jiang; Teng, Lisong

2016-01-01

Rcinoma-associated fibroblasts (CAFs) are a major constituent of the tumor microenvironment. Cancer cells can induce the transformation from normal fibroblasts (NFs) into CAFs, reciprocally, CAFs promote tumor invasion and proliferation. TGF-β has been the mostly accepted factor to fuel NFs transformation into CAFs. Galectin-1 (Gal1) is highly upregulated in CAFs of multiple human cancers, and overexpression of Gal1 in CAFs promotes tumor progression. The effect of Gal1 on TGF-β-induced CAFs activation has not yet been established in gastric cancer (GC). In this study, we show that Gal1 expression in stroma is positively related to TGF-β in epithelial cells by retrospective analysis of GC patient samples. Meanwhile, conditioned media (CMs) from gastric cancer cells induce expression of both Gal1 and the CAFs marker alpha smooth muscle actin (α-SMA) in NFs via TGF-β secretion. Knockdown of Gal1 prevents TGF-β-induced the conversion of NFs to CAFs. CMs from fibroblasts overexpressing Gal1 inhibits cancer cells apoptosis, promotes migration and invasion in vitro. Thus, Gal1 is significantly involved in the development of tumor-promoting microenvironment by enhancing TGF-β signaling in a positive feedback loop. Targeting Gal1 in tumor stroma should be considered as a potential therapeutic target for GC. PMID:27186290

MiR-93-5p promotes gastric cancer-cell progression via inactivation of the Hippo signaling pathway.

PubMed

Li, Li; Zhao, Jianguo; Huang, Shanshan; Wang, Yi; Zhu, Lingling; Cao, Yuan; Xiong, Jianping; Deng, Jun

2018-01-30

MiR-93-5p has been previously found to be associated with gastric cancer (GC) tumorigenesis; however, the current understanding of its function in this context remains largely incomplete. In the present study, we showed that miR-93-5p was upregulated in GC tissues. We also demonstrated that miR-93-5p overexpression promoted the proliferation, migration, invasion, and chemoresistance of SGC-7901 cells in vitro, and conversely, that endogenously silencing miR-93-5p expression induced the opposite effects in HGC-27 cells. Overexpression of miR-93-5p was found to inactivate the Hippo pathway, and furthermore, miR-93-5p knockdown activated Hippo signaling. MiR-93-5p upregulation was also shown to inhibit the expression of two well-characterized Hippo pathway regulators, protocadherin Fat 4 (FAT4), and large tumor suppressors 2 (LATS2), at both the mRNA and protein level. Additionally, the results of bioinformatics analyses and luciferase reporter assays indicated that miR-93-5p directly targets the 3'-UTR of FAT4 and LATS2. Taken together, these results demonstrate that miR-93-5p promotes GC-cell progression via the inactivation of the Hippo signaling pathway, and thus, represents a potential therapeutic target for the treatment of GC. Copyright © 2017. Published by Elsevier B.V.

Cardiomyocyte-enriched protein CIP protects against pathophysiological stresses and regulates cardiac homeostasis.

PubMed

Huang, Zhan-Peng; Kataoka, Masaharu; Chen, Jinghai; Wu, Gengze; Ding, Jian; Nie, Mao; Lin, Zhiqiang; Liu, Jianming; Hu, Xiaoyun; Ma, Lixin; Zhou, Bin; Wakimoto, Hiroko; Zeng, Chunyu; Kyselovic, Jan; Deng, Zhong-Liang; Seidman, Christine E; Seidman, J G; Pu, William T; Wang, Da-Zhi

2015-11-02

Cardiomyopathy is a common human disorder that is characterized by contractile dysfunction and cardiac remodeling. Genetic mutations and altered expression of genes encoding many signaling molecules and contractile proteins are associated with cardiomyopathy; however, how cardiomyocytes sense pathophysiological stresses in order to then modulate cardiac remodeling remains poorly understood. Here, we have described a regulator in the heart that harmonizes the progression of cardiac hypertrophy and dilation. We determined that expression of the myocyte-enriched protein cardiac ISL1-interacting protein (CIP, also known as MLIP) is reduced in patients with dilated cardiomyopathy. As CIP is highly conserved between human and mouse, we evaluated the effects of CIP deficiency on cardiac remodeling in mice. Deletion of the CIP-encoding gene accelerated progress from hypertrophy to heart failure in several cardiomyopathy models. Conversely, transgenic and AAV-mediated CIP overexpression prevented pathologic remodeling and preserved cardiac function. CIP deficiency combined with lamin A/C deletion resulted in severe dilated cardiomyopathy and cardiac dysfunction in the absence of stress. Transcriptome analyses of CIP-deficient hearts revealed that the p53- and FOXO1-mediated gene networks related to homeostasis are disturbed upon pressure overload stress. Moreover, FOXO1 overexpression suppressed stress-induced cardiomyocyte hypertrophy in CIP-deficient cardiomyocytes. Our studies identify CIP as a key regulator of cardiomyopathy that has potential as a therapeutic target to attenuate heart failure progression.

Cardiomyocyte-enriched protein CIP protects against pathophysiological stresses and regulates cardiac homeostasis

PubMed Central

Huang, Zhan-Peng; Kataoka, Masaharu; Chen, Jinghai; Wu, Gengze; Ding, Jian; Nie, Mao; Lin, Zhiqiang; Liu, Jianming; Hu, Xiaoyun; Ma, Lixin; Zhou, Bin; Wakimoto, Hiroko; Zeng, Chunyu; Kyselovic, Jan; Deng, Zhong-Liang; Seidman, Christine E.; Seidman, J.G.; Pu, William T.; Wang, Da-Zhi

2015-01-01

Cardiomyopathy is a common human disorder that is characterized by contractile dysfunction and cardiac remodeling. Genetic mutations and altered expression of genes encoding many signaling molecules and contractile proteins are associated with cardiomyopathy; however, how cardiomyocytes sense pathophysiological stresses in order to then modulate cardiac remodeling remains poorly understood. Here, we have described a regulator in the heart that harmonizes the progression of cardiac hypertrophy and dilation. We determined that expression of the myocyte-enriched protein cardiac ISL1-interacting protein (CIP, also known as MLIP) is reduced in patients with dilated cardiomyopathy. As CIP is highly conserved between human and mouse, we evaluated the effects of CIP deficiency on cardiac remodeling in mice. Deletion of the CIP-encoding gene accelerated progress from hypertrophy to heart failure in several cardiomyopathy models. Conversely, transgenic and AAV-mediated CIP overexpression prevented pathologic remodeling and preserved cardiac function. CIP deficiency combined with lamin A/C deletion resulted in severe dilated cardiomyopathy and cardiac dysfunction in the absence of stress. Transcriptome analyses of CIP-deficient hearts revealed that the p53- and FOXO1-mediated gene networks related to homeostasis are disturbed upon pressure overload stress. Moreover, FOXO1 overexpression suppressed stress-induced cardiomyocyte hypertrophy in CIP-deficient cardiomyocytes. Our studies identify CIP as a key regulator of cardiomyopathy that has potential as a therapeutic target to attenuate heart failure progression. PMID:26436652

Role of Dicer1 in thyroid cell proliferation and differentiation.

PubMed

Penha, Ricardo Cortez Cardoso; Sepe, Romina; De Martino, Marco; Esposito, Francesco; Pellecchia, Simona; Raia, Maddalena; Del Vecchio, Luigi; Decaussin-Petrucci, Myriam; De Vita, Gabriella; Pinto, Luis Felipe Ribeiro; Fusco, Alfredo

2017-01-01

DICER1 plays a central role in the biogenesis of microRNAs and it is important for normal development. Altered microRNA expression and DICER1 dysregulation have been described in several types of tumors, including thyroid carcinomas. Recently, our group identified a new somatic mutation (c.5438A>G; E1813G) within DICER1 gene of an unknown function. Herein, we show that DICER1 is overexpressed, at mRNA level, in a significant-relative number of papillary (70%) and anaplastic (42%) thyroid carcinoma samples, whereas is drastically downregulated in all the analyzed human thyroid carcinoma cell lines (TPC-1, BCPAP, FRO and 8505c) in comparison with normal thyroid tissue samples. Conversely, DICER1 is downregulated, at protein level, in PTC in comparison with normal thyroid tissues. Our data also reveals that DICER1 overexpression positively regulates thyroid cell proliferation, whereas its silencing impairs thyroid cell differentiation. The expression of DICER1 gene mutation (c.5438A>G; E1813G) negatively affects the microRNA machinery and cell proliferation as well as upregulates DICER1 protein levels of thyroid cells but has no impact on thyroid differentiation. In conclusion, DICER1 protein is downregulated in papillary thyroid carcinomas and affects thyroid proliferation and differentiation, while DICER1 gene mutation (c.5438A>G; E1813G) compromises the DICER1 wild-type-mediated microRNA processing and cell proliferation.

Arabidopsis WRKY45 transcription factor activates PHOSPHATE TRANSPORTER1;1 expression in response to phosphate starvation.

PubMed

Wang, Hui; Xu, Qian; Kong, You-Han; Chen, Yun; Duan, Jun-Ye; Wu, Wei-Hua; Chen, Yi-Fang

2014-04-01

The WRKY transcription factor family has more than 70 members in the Arabidopsis (Arabidopsis thaliana) genome, and some of them are involved in plant responses to biotic and abiotic stresses. This study evaluated the role of WRKY45 in regulating phosphate (Pi) uptake in Arabidopsis. WRKY45 was localized in the nucleus and mainly expressed in roots. During Pi starvation, WRKY45 expression was markedly induced, typically in roots. WRKY45 overexpression in Arabidopsis increased Pi content and uptake, while RNA interference suppression of WRKY45 decreased Pi content and uptake. Furthermore, the WRKY45-overexpressing lines were more sensitive to arsenate, the analog of Pi, compared with wild-type seedlings. These results indicate that WRKY45 positively regulates Arabidopsis Pi uptake. Quantitative real-time polymerase chain reaction and β-glucuronidase staining assays showed that PHOSPHATE TRANSPORTER1;1 (PHT1;1) expression was enhanced in the WRKY45-overexpressing lines and slightly repressed in the WRKY45 RNA interference line. Chromatin immunoprecipitation and electrophoretic mobility shift assay results indicated that WRKY45 can bind to two W-boxes within the PHT1;1 promoter, confirming the role of WRKY45 in directly up-regulating PHT1;1 expression. The pht1;1 mutant showed decreased Pi content and uptake, and overexpression of PHT1;1 resulted in enhanced Pi content and uptake. Furthermore, the PHT1;1-overexpressing line was much more sensitive to arsenate than WRKY45-overexpressing and wild-type seedlings, indicating that PHT1;1 overexpression can enhance Arabidopsis Pi uptake. Moreover, the enhanced Pi uptake and the increased arsenate sensitivity of the WRKY45-overexpressing line was impaired by pht1;1 (35S:WRKY45-18::pht1;1), demonstrating an epistatic genetic regulation between WRKY45 and PHT1;1. Together, our results demonstrate that WRKY45 is involved in Arabidopsis response to Pi starvation by direct up-regulation of PHT1;1 expression.

G protein-coupled receptor 84 controls osteoclastogenesis through inhibition of NF-κB and MAPK signaling pathways.

PubMed

Park, Ji-Wan; Yoon, Hye-Jin; Kang, Woo Youl; Cho, Seungil; Seong, Sook Jin; Lee, Hae Won; Yoon, Young-Ran; Kim, Hyun-Ju

2018-02-01

GPR84, a member of the G protein-coupled receptor family, is found predominantly in immune cells, such as macrophages, and functions as a pivotal modulator of inflammatory responses. In this study, we investigated the role of GPR84 in receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation. Our microarray data showed that GPR84 was significantly downregulated in osteoclasts compared to in their precursors, macrophages. The overexpression of GPR84 in bone marrow-derived macrophages suppressed the formation of multinucleated osteoclasts without affecting precursor proliferation. In addition, GPR84 overexpression attenuated the induction of c-Fos and nuclear factor of activated T cells, cytoplasmic 1 (NFATc1), which are transcription factors that are critical for osteoclastogenesis. Furthermore, knockdown of GPR84 using a small hairpin RNA promoted RANKL-mediated osteoclast differentiation and gene expression of osteoclastogenic markers. Mechanistically, GPR84 overexpression blocked RANKL-stimulated phosphorylation of IκBα and three MAPKs, JNK, ERK, and p38. GPR84 also suppressed NF-κB transcriptional activity mediated by RANKL. Conversely, GPR84 knockdown enhanced RANKL-induced activation of IκBα and the three MAPKs. Collectively, our results revealed that GPR84 functions as a negative regulator of osteoclastogenesis, suggesting that it may be a potential therapeutic target for osteoclast-mediated bone-destructive diseases. © 2017 Wiley Periodicals, Inc.

Expression of klotho mRNA and protein in rat brain parenchyma from early postnatal development into adulthood

PubMed Central

Clinton, Sarah M.; Glover, Matthew E.; Maltare, Astha; Laszczyk, Ann M.; Mehi, Stephen J.; Simmons, Rebecca K.; King, Gwendalyn D.

2013-01-01

Without the age-regulating protein klotho, mouse lifespan is shortened and the rapid onset of age-related disorders occurs. Conversely, overexpression of klotho extends mouse lifespan. Klotho is most abundant in kidney and expressed in a limited number of other organs, including the brain, where klotho levels are highest in choroid plexus. Reports vary on where klotho is expressed within the brain parenchyma, and no data is available as to whether klotho levels change across postnatal development. We used in situ hybridization to map klotho mRNA expression in the developing and adult rat brain and report moderate, widespread expression across grey matter regions. mRNA expression levels in cortex, hippocampus, caudate putamen, and amygdala decreased during the second week of life and then gradually rose to adult levels by postnatal day 21. Immunohistochemistry revealed a protein expression pattern similar to the mRNA results, with klotho protein expressed widely throughout the brain. Klotho protein co-localized with both the neuronal marker NeuN, as well as, oligodendrocyte marker olig2. These results provide the first anatomical localization of klotho mRNA and protein in rat brain parenchyma and demonstrate that klotho levels vary during early postnatal development. PMID:23838326

Prediction of recombinant protein overexpression in Escherichia coli using a machine learning based model (RPOLP).

PubMed

Habibi, Narjeskhatoon; Norouzi, Alireza; Mohd Hashim, Siti Z; Shamsir, Mohd Shahir; Samian, Razip

2015-11-01

Recombinant protein overexpression, an important biotechnological process, is ruled by complex biological rules which are mostly unknown, is in need of an intelligent algorithm so as to avoid resource-intensive lab-based trial and error experiments in order to determine the expression level of the recombinant protein. The purpose of this study is to propose a predictive model to estimate the level of recombinant protein overexpression for the first time in the literature using a machine learning approach based on the sequence, expression vector, and expression host. The expression host was confined to Escherichia coli which is the most popular bacterial host to overexpress recombinant proteins. To provide a handle to the problem, the overexpression level was categorized as low, medium and high. A set of features which were likely to affect the overexpression level was generated based on the known facts (e.g. gene length) and knowledge gathered from related literature. Then, a representative sub-set of features generated in the previous objective was determined using feature selection techniques. Finally a predictive model was developed using random forest classifier which was able to adequately classify the multi-class imbalanced small dataset constructed. The result showed that the predictive model provided a promising accuracy of 80% on average, in estimating the overexpression level of a recombinant protein. Copyright © 2015 Elsevier Ltd. All rights reserved.

HIF-2α mediates hypoxia-induced LIF expression in human colorectal cancer cells

PubMed Central

Zhao, Yuhan; Zhang, Cen; Wang, Jiabei; Yue, Xuetian; Yang, Qifeng; Hu, Wenwei

2015-01-01

Leukemia inhibitory factor (LIF), a multi-functional cytokine, has a complex role in cancer. While LIF induces the differentiation of several myeloid leukemia cells and inhibits their growth, it also promotes tumor progression, metastasis and chemoresistance in many solid tumors. LIF is frequently overexpressed in a variety of human tumors and its overexpression is often associated with poor prognosis of patients. Currently, the mechanism for LIF overexpression in tumor cells is not well-understood. Here, we report that hypoxia, a hallmark of solid tumors, induced LIF mRNA expression in human colorectal cancer cells. Analysis of LIF promoter revealed several hypoxia-responsive elements (HREs) that can specifically interact with and be transactivated by HIF-2α but not HIF-1α. Consistently, ectopic expression of HIF-2α but not HIF-1α transcriptionally induced LIF expression levels in cells. Knockdown of endogenous HIF-2α but not HIF-1α by siRNA largely abolished the induction of LIF by hypoxia in cells. Furthermore, there is a strong association of HIF-2α overexpression with LIF overexpression in human colorectal cancer specimens. In summary, results from this study demonstrate that hypoxia induces LIF expression in human cancer cells mainly through HIF-2α, which could be an important underlying mechanism for LIF overexpression in human cancers. PMID:25726527

Protection against vascular leak in neprilysin transgenic mice with complex overexpression pattern.

PubMed

Wick, Marilee J; Loomis, Zoe L; Harral, Julie W; Le, Mysan; Wehling, Carol A; Miller, York E; Dempsey, Edward C

2016-12-01

Neprilysin (NEP) is a cell surface metallopeptidase found in many tissues. Based mostly on pharmacological manipulations, NEP has been thought to protect blood vessels from plasma extravasation. We have suggested that NEP may protect against pulmonary vascular injury. However, these prior studies did not utilize mice which overexpress NEP. The aims of the present investigation were to develop and characterize doubly transgenic (DT) mice that overexpress NEP universally and conditionally, and to investigate the protective effect that overexpressed NEP may have against plasma extravasation in the vasculature. The duodenum, which is often used to assess vascular permeability, and in which the NEP protein was overexpressed in our DT mice two-fold, was selected as our experimental preparation. We found that substance P-induced plasma extravasation was decreased substantially (3.5-fold) in the duodenums of our doxycycline-treated DT mice, giving independent evidence of NEP's protective effects against plasma extravasation. Transgenic lung NEP protein was not stably expressed in the DT mice, so we were not able to test the effect of NEP overexpression in the lung. Although initially overexpressed nearly nine-fold at that site, pulmonary NEP protein overexpression eventually dissipated. Surprisingly, at a time when there was no lung transgenic NEP protein overexpression, lung NEP mRNA expression was still increased 23-fold, indicating that the expression defect probably is not transcriptional. These studies help to characterize our complex transgenic model of NEP overexpression and further demonstrate NEP's protective effects against plasma extravasation.

Overexpression of GA20-OXIDASE1 impacts plant height, biomass allocation and saccharification efficiency in maize.

PubMed

Voorend, Wannes; Nelissen, Hilde; Vanholme, Ruben; De Vliegher, Alex; Van Breusegem, Frank; Boerjan, Wout; Roldán-Ruiz, Isabel; Muylle, Hilde; Inzé, Dirk

2016-03-01

Increased biomass yield and quality are of great importance for the improvement of feedstock for the biorefinery. For the production of bioethanol, both stem biomass yield and the conversion efficiency of the polysaccharides in the cell wall to fermentable sugars are of relevance. Increasing the endogenous levels of gibberellic acid (GA) by ectopic expression of GA20-OXIDASE1 (GA20-OX1), the rate-limiting step in GA biosynthesis, is known to affect cell division and cell expansion, resulting in larger plants and organs in several plant species. In this study, we examined biomass yield and quality traits of maize plants overexpressing GA20-OX1 (GA20-OX1). GA20-OX1 plants accumulated more vegetative biomass than control plants in greenhouse experiments, but not consistently over two years of field trials. The stems of these plants were longer but also more slender. Investigation of GA20-OX1 biomass quality using biochemical analyses showed the presence of more cellulose, lignin and cell wall residue. Cell wall analysis as well as expression analysis of lignin biosynthetic genes in developing stems revealed that cellulose and lignin were deposited earlier in development. Pretreatment of GA20-OX1 biomass with NaOH resulted in a higher saccharification efficiency per unit of dry weight, in agreement with the higher cellulose content. On the other hand, the cellulose-to-glucose conversion was slower upon HCl or hot-water pretreatment, presumably due to the higher lignin content. This study showed that biomass yield and quality traits can be interconnected, which is important for the development of future breeding strategies to improve lignocellulosic feedstock for bioethanol production. © 2015 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Examination of thromboxane synthase as a prognostic factor and therapeutic target in non-small cell lung cancer.

PubMed

Cathcart, Mary-Clare; Gately, Kathy; Cummins, Robert; Kay, Elaine; O'Byrne, Kenneth J; Pidgeon, Graham P

2011-03-09

Thromboxane synthase (TXS) metabolises prostaglandin H2 into thromboxanes, which are biologically active on cancer cells. TXS over-expression has been reported in a range of cancers, and associated with a poor prognosis. TXS inhibition induces cell death in-vitro, providing a rationale for therapeutic intervention. We aimed to determine the expression profile of TXS in NSCLC and if it is prognostic and/or a survival factor in the disease. TXS expression was examined in human NSCLC and matched controls by western analysis and IHC. TXS metabolite (TXB2) levels were measured by EIA. A 204-patient NSCLC TMA was stained for COX-2 and downstream TXS expression. TXS tissue expression was correlated with clinical parameters, including overall survival. Cell proliferation/survival and invasion was examined in NSCLC cells following both selective TXS inhibition and stable TXS over-expression. TXS was over-expressed in human NSCLC samples, relative to matched normal controls. TXS and TXB2 levels were increased in protein (p < 0.05) and plasma (p < 0.01) NSCLC samples respectively. TXS tissue expression was higher in adenocarcinoma (p < 0.001) and female patients (p < 0.05). No significant correlation with patient survival was observed. Selective TXS inhibition significantly reduced tumour cell growth and increased apoptosis, while TXS over-expression stimulated cell proliferation and invasiveness, and was protective against apoptosis. TXS is over-expressed in NSCLC, particularly in the adenocarcinoma subtype. Inhibition of this enzyme inhibits proliferation and induces apoptosis. Targeting thromboxane synthase alone, or in combination with conventional chemotherapy is a potential therapeutic strategy for NSCLC.

Cardiac Fibroblast-Specific Activating Transcription Factor 3 Protects Against Heart Failure by Suppressing MAP2K3-p38 Signaling.

PubMed

Li, Yulin; Li, Zhenya; Zhang, Congcong; Li, Ping; Wu, Yina; Wang, Chunxiao; Bond Lau, Wayne; Ma, Xin-Liang; Du, Jie

2017-05-23

Hypertensive ventricular remodeling is a common cause of heart failure. However, the molecular mechanisms regulating ventricular remodeling remain poorly understood. We used a discovery-driven/nonbiased approach to identify increased activating transcription factor 3 (ATF3) expression in hypertensive heart. We used loss/gain of function approaches to understand the role of ATF3 in heart failure. We also examined the mechanisms through transcriptome, chromatin immunoprecipitation sequencing analysis, and in vivo and in vitro experiments. ATF3 expression increased in murine hypertensive heart and human hypertrophic heart. Cardiac fibroblast cells are the primary cell type expressing high ATF3 levels in response to hypertensive stimuli. ATF3 knockout (ATF3KO) markedly exaggerated hypertensive ventricular remodeling, a state rescued by lentivirus-mediated/miRNA-aided cardiac fibroblast-selective ATF3 overexpression. Conversely, conditional cardiac fibroblast cell-specific ATF3 transgenic overexpression significantly ameliorated ventricular remodeling and heart failure. We identified Map2K3 as a novel ATF3 target. ATF3 binds with the Map2K3 promoter, recruiting HDAC1, resulting in Map2K3 gene-associated histone deacetylation, thereby inhibiting Map2K3 expression. Genetic Map2K3 knockdown rescued the profibrotic/hypertrophic phenotype in ATF3KO cells. Last, we demonstrated that p38 is the downstream molecule of Map2K3 mediating the profibrotic/hypertrophic effects in ATF3KO animals. Inhibition of p38 signaling reduced transforming growth factor-β signaling-related profibrotic and hypertrophic gene expression, and blocked exaggerated cardiac remodeling in ATF3KO cells. Our study provides the first evidence that ATF3 upregulation in cardiac fibroblasts in response to hypertensive stimuli protects the heart by suppressing Map2K3 expression and subsequent p38-transforming growth factor-β signaling. These results suggest that positive modulation of cardiac fibroblast ATF3 may represent a novel therapeutic approach against hypertensive cardiac remodeling. © 2017 American Heart Association, Inc.

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

Gopalan, Vinod; Islam, Farhadul; Pillai, Suja

Purpose: This study aims to examine the expression profiles miR-1288 in oesophageal squamous cell carcinoma (ESCC). The cellular implications and target interactions of ESCC cells following miR-1288 overexpression was also examined. Methods: In total, 120 oesophageal tissues (90 primary ESCCs and 30 non-neoplastic tissues) were recruited for miR-1288 expression analysis using qRT-PCR. An exogenous miR-1288 mimic and its inhibitor were used to explore the in-vitro effects of miR-1288 on ESCC cells by performing cell proliferation, colony formation, cell invasion and migration assays. Localisation and modulatory changes of various miR-1288 regulated proteins such as FOXO1, p53, TAB3, BCL2 and kRAS wasmore » examined using immunofluorescence and western blot. Results: Overexpression of miR-1288 was more often noted in ESCC tissues when compared to non-neoplastic oesophageal tissues. High expression was often noted in high grade carcinomas and with metastases. Patients with high levels of miR-1288 expression showed a slightly better survival compared to patients with low miR-1288 levels. Furthermore, overexpression of miR-1288 showed increased cell proliferation and colony formation, improved cell migration and enhanced cell invasion properties in ESCC cells. In addition, miR-1288 overexpression in ESCC cells showed repression of cytoplasmic tumour suppressor FOXO1 protein expression. Inversely, inhibition of miR-1288 expression exhibited remarkable upregulation of FOXO1 protein, while expressions of other tested proteins remain unchanged. Conclusions: Up regulation of miR-1288 expression in ESCC tissues and miR-1288 induced oncogenic features of ESCC cells in-vitro indicates the oncogenic roles of miR-1288 in ESCCs. Overexpression of miR-1288 play a key role in the pathogenesis of ESCCs and its modulation may have potential therapeutic value in patients with ESCC. - Highlights: • miR-1288 was more often noted in neoplastic than non-neoplastic tissue. • miR-1288 overexpression increased proliferative/invasive activities of ESCC. • miR-1288 overexpression showed repression of FOXO1 protein expression. • miR-1288 functions as an oncogenic miRNA in ESCCs.« less

Inhibition of Reticulon-1A-Mediated Endoplasmic Reticulum Stress in Early AKI Attenuates Renal Fibrosis Development.

PubMed

Fan, Ying; Xiao, Wenzhen; Lee, Kyung; Salem, Fadi; Wen, Jiejun; He, Li; Zhang, Jing; Fei, Yang; Cheng, Dongsheng; Bao, Hongda; Liu, Yumei; Lin, Fujun; Jiang, Gengru; Guo, Zhiyong; Wang, Niansong; He, John Cijiang

2017-07-01

Several animal studies have shown an important role for endoplasmic reticulum (ER) stress in AKI, whereas human studies are lacking. We recently reported that Reticulon-1A (RTN1A) is a key mediator of ER stress and kidney cell injury. Here, we investigated whether modulation of RTN1A expression during AKI contributes to the progression to CKD. In a retrospective study of 51 patients with AKI, increased expression of RTN1A and other ER stress markers were associated with the severity of kidney injury and with progression to CKD. In an inducible tubular cell-specific RTN1A-knockdown mouse model subjected to folic acid nephropathy (FAN) or aristolochic acid nephropathy, reduction of RTN1A expression during the initial stage of AKI attenuated ER stress and kidney cell injury in early stages and renal fibrosis development in later stages. Treatment of wild-type mice with tauroursodeoxycholic acid, an inhibitor of ER stress, after the induction of kidney injury with FA facilitated renoprotection similar to that observed in RTN1A-knockdown mice. Conversely, in transgenic mice with inducible tubular cell-specific overexpression of RTN1A subjected to FAN, induction of RTN1A overexpression aggravated ER stress and renal injury at the early stage and renal fibrosis at the late stage of FAN. Together, our human and mouse data suggest that the RTN1A-mediated ER stress response may be an important determinant in the severity of AKI and maladaptive repair that may promote progression to CKD. Copyright © 2017 by the American Society of Nephrology.

A mutation in MYD88 (L265P) supports the survival of lymphoplasmacytic cells by activation of Bruton tyrosine kinase in Waldenström macroglobulinemia.

PubMed

Yang, Guang; Zhou, Yangsheng; Liu, Xia; Xu, Lian; Cao, Yang; Manning, Robert J; Patterson, Christopher J; Buhrlage, Sara J; Gray, Nathanael; Tai, Yu-Tzu; Anderson, Kenneth C; Hunter, Zachary R; Treon, Steven P

2013-08-15

Myeloid differentiation factor 88 (MYD88) L265P somatic mutation is highly prevalent in Waldenström macroglobulinemia (WM) and supports malignant growth through nuclear factor κB (NF-κB). The signaling cascade(s) by which MYD88 L265P promotes NF-κB activation in WM remain unclear. By lentiviral knockdown or use of a MYD88 inhibitor, decreased phosphorylation of the NF-κB gatekeeper IκBα and survival occurred in MYD88 L265P-expressing WM cells. Conversely, WM cells engineered to overexpress MYD88 L265P showed enhanced survival. Coimmunoprecipitation studies identified Bruton tyrosine kinase (BTK) complexed to MYD88 in L265P-expressing WM cells, with preferential binding of MYD88 to phosphorylated BTK (pBTK). Increased pBTK was also observed in WM cells transduced to overexpress L265P vs wild-type MYD88. Importantly, MYD88 binding to BTK was abrogated following treatment of MYD88 L265P-expressing cells with a BTK kinase inhibitor. Inhibition of BTK or interleukin-1 receptor-associated kinase 1 and 4 (IRAK-1 and -4) kinase activity induced apoptosis of WM cells, and their combination resulted in more robust inhibition of NF-κB signaling and synergistic WM cell killing. The results establish BTK as a downstream target of MYD88 L265P signaling, and provide a framework for the study of BTK inhibitors alone, and in combination with IRAK inhibitors for the treatment of WM.

Four and a Half LIM Domains 1b (Fhl1b) Is Essential for Regulating the Liver versus Pancreas Fate Decision and for β-Cell Regeneration

PubMed Central

Xu, Jin; Cui, Jiaxi; Del Campo, Aranzazu; Shin, Chong Hyun

2016-01-01

The liver and pancreas originate from overlapping embryonic regions, and single-cell lineage tracing in zebrafish has shown that Bone morphogenetic protein 2b (Bmp2b) signaling is essential for determining the fate of bipotential hepatopancreatic progenitors towards the liver or pancreas. Despite its pivotal role, the gene regulatory networks functioning downstream of Bmp2b signaling in this process are poorly understood. We have identified four and a half LIM domains 1b (fhl1b), which is primarily expressed in the prospective liver anlage, as a novel target of Bmp2b signaling. fhl1b depletion compromised liver specification and enhanced induction of pancreatic cells from endodermal progenitors. Conversely, overexpression of fhl1b favored liver specification and inhibited induction of pancreatic cells. By single-cell lineage tracing, we showed that fhl1b depletion led lateral endodermal cells, destined to become liver cells, to become pancreatic cells. Reversely, when fhl1b was overexpressed, medially located endodermal cells, fated to differentiate into pancreatic and intestinal cells, contributed to the liver by directly or indirectly modulating the discrete levels of pdx1 expression in endodermal progenitors. Moreover, loss of fhl1b increased the regenerative capacity of β-cells by increasing pdx1 and neurod expression in the hepatopancreatic ductal system. Altogether, these data reveal novel and critical functions of Fhl1b in the hepatic versus pancreatic fate decision and in β-cell regeneration. PMID:26845333

Wnt5 and Drl/Ryk Gradients Pattern the Drosophila Olfactory Dendritic Map

PubMed Central

Wu, Yuping; Helt, Jay-Christian; Wexler, Emily; Petrova, Iveta M.; Noordermeer, Jasprina N.; Fradkin, Lee G.

2014-01-01

During development, dendrites migrate to their correct locations in response to environmental cues. The mechanisms of dendritic guidance are poorly understood. Recent work has shown that the Drosophila olfactory map is initially formed by the spatial segregation of the projection neuron (PN) dendrites in the developing antennal lobe (AL). We report here that between 16 and 30 h after puparium formation, the PN dendrites undergo dramatic rotational reordering to achieve their final glomerular positions. During this period, a novel set of AL-extrinsic neurons express high levels of the Wnt5 protein and are tightly associated with the dorsolateral edge of the AL. Wnt5 forms a dorsolateral-high to ventromedial-low pattern in the antennal lobe neuropil. Loss of Wnt5 prevents the ventral targeting of the dendrites, whereas Wnt5 overexpression disrupts dendritic patterning. We find that Drl/Ryk, a known Wnt5 receptor, is expressed in a dorsolateral-to-ventromedial (DL > VM) gradient by the PN dendrites. Loss of Drl in the PNs results in the aberrant ventromedial targeting of the dendrites, a defect that is suppressed by reduction in Wnt5 gene dosage. Conversely, overexpression of Drl in the PNs results in the dorsolateral targeting of their dendrites, an effect that requires Drl's cytoplasmic domain. We propose that Wnt5 acts as a repulsive guidance cue for the PN dendrites, whereas Drl signaling in the dendrites inhibits Wnt5 signaling. In this way, the precise expression patterns of Wnt5 and Drl orient the PN dendrites allowing them to target their final glomerular positions. PMID:25378162

Protein arginine methyltransferase 7 promotes breast cancer cell invasion through the induction of MMP9 expression

PubMed Central

Baldwin, R. Mitchell; Haghandish, Nasim; Daneshmand, Manijeh; Amin, Shahrier; Paris, Geneviève; Falls, Theresa J.; Bell, John C.; Islam, Shahidul; Côté, Jocelyn

2015-01-01

Recent evidence points to the protein arginine methyltransferase (PRMT) family of enzymes playing critical roles in cancer. PRMT7 has been identified in several gene expression studies to be associated with increased metastasis and decreased survival in breast cancer patients. However, this has not been extensively studied. Here we report that PRMT7 expression is significantly upregulated in both primary breast tumour tissues and in breast cancer lymph node metastases. We have demonstrated that reducing PRMT7 levels in invasive breast cancer cells using RNA interference significantly decreased cell invasion in vitro and metastasis in vivo. Conversely, overexpression of PRMT7 in non-aggressive MCF7 cells enhanced their invasiveness. Furthermore, we show that PRMT7 induces the expression of matrix metalloproteinase 9 (MMP9), a well-known mediator of breast cancer metastasis. Importantly, we significantly rescued invasion of aggressive breast cancer cells depleted of PRMT7 by the exogenous expression of MMP9. Our results demonstrate that upregulation of PRMT7 in breast cancer may have a significant role in promoting cell invasion through the regulation of MMP9. This identifies PRMT7 as a novel and potentially significant biomarker and therapeutic target for breast cancer. PMID:25605249

Protein arginine methyltransferase 7 promotes breast cancer cell invasion through the induction of MMP9 expression.

PubMed

Baldwin, R Mitchell; Haghandish, Nasim; Daneshmand, Manijeh; Amin, Shahrier; Paris, Geneviève; Falls, Theresa J; Bell, John C; Islam, Shahidul; Côté, Jocelyn

2015-02-20

Recent evidence points to the protein arginine methyltransferase (PRMT) family of enzymes playing critical roles in cancer. PRMT7 has been identified in several gene expression studies to be associated with increased metastasis and decreased survival in breast cancer patients. However, this has not been extensively studied. Here we report that PRMT7 expression is significantly upregulated in both primary breast tumour tissues and in breast cancer lymph node metastases. We have demonstrated that reducing PRMT7 levels in invasive breast cancer cells using RNA interference significantly decreased cell invasion in vitro and metastasis in vivo. Conversely, overexpression of PRMT7 in non-aggressive MCF7 cells enhanced their invasiveness. Furthermore, we show that PRMT7 induces the expression of matrix metalloproteinase 9 (MMP9), a well-known mediator of breast cancer metastasis. Importantly, we significantly rescued invasion of aggressive breast cancer cells depleted of PRMT7 by the exogenous expression of MMP9. Our results demonstrate that upregulation of PRMT7 in breast cancer may have a significant role in promoting cell invasion through the regulation of MMP9. This identifies PRMT7 as a novel and potentially significant biomarker and therapeutic target for breast cancer.

Expression of insulin-like growth factor-2 receptors on EL4 lymphoma cells overexpressing growth hormone.

PubMed

Farmer, John T; Weigent, Douglas A

2007-01-01

In the present study, we report the upregulation of functional IGF-2Rs in cells overexpressing growth hormone (GH). EL4 lymphoma cells stably transfected with an rGH cDNA overexpression vector (GHo) exhibited an increase in the binding of (125)I-IGF-2 with no change in the binding affinity compared to vector alone controls. An increase in the expression of the insulin-like growth factor-2 receptor (IGF-2R) in cells overexpressing GH was confirmed by Western blot analysis and IGF-2R promoter luciferase assays. EL4 cells produce insulin-like growth factor-2 (IGF-2) as detected by the reverse transcription-polymerase chain reaction (RT-PCR); however, no IGF-2 protein was detected by Western analysis. The increase in the expression of the IGF-2R resulted in greater levels of IGF-2 uptake in GHo cells compared to vector alone controls. The data suggest that one of the consequences of the overexpression of GH is an increase in the expression of the IGF-2R.

Over-expression of phage HK022 Nun protein is toxic for Escherichia coli

PubMed Central

Uc-Mass, Augusto; Khodursky, Arkady; Brown, Lewis; Gottesman, Max E.

2008-01-01

The Nun protein of coliphage HK022 excludes superinfecting λ phage. Nun recognizes and binds to the N utilization (nut) sites on phage λ nascent RNA and induces transcription termination. Over-expression of Nun from a high-copy plasmid is toxic for E.coli, despite the fact that nut sites are not encoded in the E.coli genome. Cells expressing Nun cannot exit stationary phase. Toxicity is related to transcription termination, since host and nun mutations that block termination also suppress cell killing. Nun inhibits expression of wild-type lacZ, but not lacZ expressed from the Crp/cAMP–independent lacUV5 promoter. Microarray and proteomics analyses show Nun down-regulates crp and tnaA. Crp over-expression and high indole concentrations partially reverse Nun-mediated toxicity and restore lacZ expression. PMID:18571198

FK506-Binding Protein 12.6/1b, a Negative Regulator of [Ca2+], Rescues Memory and Restores Genomic Regulation in the Hippocampus of Aging Rats

PubMed Central

Gant, John C.; Blalock, Eric M.; Chen, Kuey-Chu; Kadish, Inga; Thibault, Olivier; Porter, Nada M.

2018-01-01

Hippocampal overexpression of FK506-binding protein 12.6/1b (FKBP1b), a negative regulator of ryanodine receptor Ca2+ release, reverses aging-induced memory impairment and neuronal Ca2+ dysregulation. Here, we tested the hypothesis that FKBP1b also can protect downstream transcriptional networks from aging-induced dysregulation. We gave hippocampal microinjections of FKBP1b-expressing viral vector to male rats at either 13 months of age (long-term, LT) or 19 months of age (short-term, ST) and tested memory performance in the Morris water maze at 21 months of age. Aged rats treated ST or LT with FKBP1b substantially outperformed age-matched vector controls and performed similarly to each other and young controls (YCs). Transcriptional profiling in the same animals identified 2342 genes with hippocampal expression that was upregulated/downregulated in aged controls (ACs) compared with YCs (the aging effect). Of these aging-dependent genes, 876 (37%) also showed altered expression in aged FKBP1b-treated rats compared with ACs, with FKBP1b restoring expression of essentially all such genes (872/876, 99.5%) in the direction opposite the aging effect and closer to levels in YCs. This inverse relationship between the aging and FKBP1b effects suggests that the aging effects arise from FKBP1b deficiency. Functional category analysis revealed that genes downregulated with aging and restored by FKBP1b were associated predominantly with diverse brain structure categories, including cytoskeleton, membrane channels, and extracellular region. Conversely, genes upregulated with aging but not restored by FKBP1b associated primarily with glial–neuroinflammatory, ribosomal, and lysosomal categories. Immunohistochemistry confirmed aging-induced rarefaction and FKBP1b-mediated restoration of neuronal microtubular structure. Therefore, a previously unrecognized genomic network modulating diverse brain structural processes is dysregulated by aging and restored by FKBP1b overexpression. SIGNIFICANCE STATEMENT Previously, we found that hippocampal overexpression of FK506-binding protein 12.6/1b (FKBP1b), a negative regulator of intracellular Ca2+ responses, reverses both aging-related Ca2+ dysregulation and cognitive impairment. Here, we tested whether hippocampal FKBP1b overexpression also counteracts aging changes in gene transcriptional networks. In addition to reducing memory deficits in aged rats, FKBP1b selectively counteracted aging-induced expression changes in 37% of aging-dependent genes, with cytoskeletal and extracellular structure categories highly associated with the FKBP1b-rescued genes. Our results indicate that, in parallel with cognitive processes, a novel transcriptional network coordinating brain structural organization is dysregulated with aging and restored by FKBP1b. PMID:29255009

Expression of Hormone Receptors and HER-2 in Benign and Malignant Salivary Gland Tumors.

PubMed

Can, Nhu Thuy; Lingen, Mark W; Mashek, Heather; McElherne, James; Briese, Renee; Fitzpatrick, Carrie; van Zante, Annemieke; Cipriani, Nicole A

2018-03-01

With the advent of targeted therapies, expression of sex hormone receptors and HER-2 in salivary gland tumors (SGTs) is of clinical interest. Previous reports of estrogen (ER) and progesterone (PR) receptor expression have varied. Androgen receptor (AR) and HER-2 overexpression are frequently reported in salivary duct carcinoma (SDC), but have not been studied systematically in other SGTs. This study examines ER, PR, AR, and HER-2 expression in SGTs. Immunohistochemistry for ER, PR, AR, and HER-2 was performed on 254 SGTs (134 malignant). ER, PR, and AR expression was scored using Allred system. HER-2 expression was scored using Dako HercepTest guidelines. FISH for HER-2 amplification was performed on select cases with HER-2 overexpression (2-3+). No SGT demonstrated strong expression of ER or PR. Combined strong AR and HER-2 expression was seen in 22 carcinomas: 14/25 SDC, 3/16 poorly differentiated, two oncocytic, and one each carcinoma ex pleomorphic adenoma, squamous cell, and intraductal carcinoma. Eighteen additional high grade carcinomas had HER-2 overexpression with absent, weak, or moderate AR expression; eight high grade carcinomas had isolated strong AR expression with 0-1+ HER-2 staining. Of 15 tested cases, six demonstrated HER-2 amplification by FISH, all of which had 3+ immunoreactivity. Neither benign nor malignant SGTs had strong expression of ER or PR. None of the benign SGTs overexpressed AR or HER-2. Coexpression of AR and HER-2 should not define SDC, but immunostaining should be considered in high grade salivary carcinomas, as some show overexpression and may benefit from targeted therapy.

Over-Expression of the Mycobacterial Trehalose-Phosphate Phosphatase OtsB2 Results in a Defect in Macrophage Phagocytosis Associated with Increased Mycobacterial-Macrophage Adhesion

PubMed Central

Li, Hao; Wu, Mei; Shi, Yan; Javid, Babak

2016-01-01

Trehalose-6-phosphate phosphatase (OtsB2) is involved in the OtsAB trehalose synthesis pathway to produce free trehalose and is strictly essential for mycobacterial growth. We wished to determine the effects of OtsB2 expression on mycobacterial phenotypes such as growth, phagocytosis and survival in macrophages. Mycobacterium bovis-bacillus calmette-guerin (BCG) over-expressing OtsB2 were able to better survive in stationary phase. Over-expression of OtsB2 led to a decrease in phagocytosis but not survival in THP-1 macrophage-like cells, and this was not due to a decrease in general macrophage phagocytic activity. Surprisingly, when we investigated macrophage–mycobacterial interactions by flow cytometry and atomic force microscopy, we discovered that BCG over-expressing OtsB2 have stronger binding to THP-1 cells than wild-type BCG. These results suggest that altering OtsB2 expression has implications for mycobacterial host–pathogen interactions. Macrophage–mycobacteria phagocytic interactions are complex and merit further study. PMID:27867377

New markers of pancreatic cancer identified through differential gene expression analyses: claudin 18 and annexin A8.

PubMed

Karanjawala, Zarir E; Illei, Peter B; Ashfaq, Raheela; Infante, Jeffrey R; Murphy, Kathleen; Pandey, Akhilesh; Schulick, Richard; Winter, Jordan; Sharma, Rajni; Maitra, Anirban; Goggins, Michael; Hruban, Ralph H

2008-02-01

New markers to distinguish benign reactive glands from infiltrating ductal adenocarcinoma of the pancreas are needed. The gene expression patterns of 24 surgically resected primary infiltrating ductal adenocarcinomas of the pancreas were compared with 18 non-neoplastic samples using the Affymetrix U133 Plus 2.0 Arrays and the Gene Logic GeneExpress Software System. Gene fragments from 4 genes (annexin A8, claudin 18, CXCL5, and S100 A2) were selected from the fragments found to be highly expressed in infiltrating adenocarcinomas when compared with normal tissues. The protein expression of these genes was examined using immunohistochemical labeling of tissue microarrays. Claudin 18 labeled infiltrating carcinomas in a membranous pattern. When compared with normal and reactive ducts, claudin 18 was overexpressed, at least focally, in 159 of 166 evaluable carcinomas (96%). Strong and diffuse claudin 18 overexpression was most often seen in well-differentiated carcinomas (P=0.02). Claudin 18 was overexpressed in 51 of 52 cases (98%) of pancreatic intraepithelial neoplasia. Annexin A8 was at least focally overexpressed in 149 of 154 evaluable infiltrating carcinomas (97%). S100 A2 was at least focally overexpressed in 118 of 154 evaluable infiltrating carcinomas (77%). Non-neoplastic glands also frequently expressed S100 A2 diminishing its potential diagnostic utility. Immunolabeling with antibodies directed against CXCL5 did not reveal any significant differences in protein expression between infiltrating adenocarcinomas and normal pancreatic ducts. Claudin 18 and annexin A8 are frequently highly overexpressed in infiltrating ductal adenocarcinomas when compared with normal reactive ducts, suggesting a role for these molecules in pancreatic ductal adenocarcinomas. Furthermore, these may serve as diagnostic markers, as screening tests and as therapeutic targets.

Krüppel-like factor 4 regulates the expression of inducible nitric oxide synthase induced by TNF-α in human fibroblast-like synoviocyte MH7A cells.

PubMed

Mo, Xuanrong; Chen, Jie; Wang, Xinjuan; Pan, Zhenyu; Ke, Yuping; Zhou, Zhidong; Xie, Jiangwen; Lv, Guoju; Luo, Xinjing

2018-01-01

Krüppel-like factor 4 (KLF4), a zinc finger transcription factor, has been implicated in the inflammation mediated by macrophages and endothelial cells by regulating the expression of inflammatory mediators. Here, we investigated whether KLF4 affects the expression of inducible nitric oxide synthase (iNOS), an important inflammatory mediator, in the human RA fibroblast-like synovial cell line MH7A. A pcDNA3.1-KLF4 plasmid or short interfering RNA KLF4 was transfected into MH7A cells, and the iNOS expression and nitric oxide (NO) production were analyzed by quantitative PCR, immunoblotting, and nitrite measurement. The iNOS promoter activity was determined by luciferase assay. The results showed overexpression of KLF4 increased iNOS expression and NO production in the presence or absence of TNF-α. Conversely, KLF4 knockdown markedly reduced iNOS expression and NO production induced by TNF-α. KLF4 activated the transcription activity of iNOS promoter in MH7A cells stimulated by TNF-α. This study indicates that KLF4 is important for regulating the expression of iNOS by TNF-α in human synoviocytes.

Over-expression of a putative oxidoreductase (UcpA) for increasing furfural or 5-hydroxymethylfurfural tolerance

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

Wang, Xuan; Miller, Elliot N.; Yomano, Lorraine P.

The subject invention pertains to overexpression of a putative oxidoreductase (ucpA) for increasing furfural tolerance in genetically modified microorganisms. Genetically modified microorganisms capable of overexpressing UcpA are also provided. Increased expression of ucpA was shown to increase furfural tolerance by 50%, and to permit the fermentation of sugars to products in the presence of 15 mM furfural.

XRCC5 cooperates with p300 to promote cyclooxygenase-2 expression and tumor growth in colon cancers

PubMed Central

Hao, Jiajiao; Chen, Miao; Yu, Wendan; Guo, Wei; Chen, Yiming; Huang, Wenlin; Deng, Wuguo

2017-01-01

Cyclooxygenase (COX) is the rate-limiting enzyme in prostaglandins (PGs) biosynthesis. Previous studies indicate that COX-2, one of the isoforms of COX, is highly expressed in colon cancers and plays a key role in colon cancer carcinogenesis. Thus, searching for novel transcription factors regulating COX-2 expression will facilitate drug development for colon cancer. In this study, we identified XRCC5 as a binding protein of the COX-2 gene promoter in colon cancer cells with streptavidin-agarose pulldown assay and mass spectrometry analysis, and found that XRCC5 promoted colon cancer growth through modulation of COX-2 signaling. Knockdown of XRCC5 by siRNAs inhibited the growth of colon cancer cells in vitro and of tumor xenografts in a mouse model in vivo by suppressing COX-2 promoter activity and COX-2 protein expression. Conversely, overexpression of XRCC5 promoted the growth of colon cancer cells by activating COX-2 promoter and increasing COX-2 protein expression. Moreover, the role of p300 (a transcription co-activator) in acetylating XRCC5 to co-regulate COX-2 expression was also evaluated. Immunofluorescence assay and confocal microscopy showed that XRCC5 and p300 proteins were co-located in the nucleus of colon cancer cells. Co-immunoprecipitation assay also proved the interaction between XRCC5 and p300 in nuclear proteins of colon cancer cells. Cell viability assay indicated that the overexpression of wild-type p300, but not its histone acetyltransferase (HAT) domain deletion mutant, increased XRCC5 acetylation, thereby up-regulated COX-2 expression and promoted the growth of colon cancer cells. In contrast, suppression of p300 by a p300 HAT-specific inhibitor (C646) inhibited colon cancer cell growth by suppressing COX-2 expression. Taken together, our results demonstrated that XRCC5 promoted colon cancer growth by cooperating with p300 to regulate COX-2 expression, and suggested that the XRCC5/p300/COX-2 signaling pathway was a potential target in the treatment of colon cancers. PMID:29049411

miR-219-1-3p is a negative regulator of the mucin MUC4 expression and is a tumor suppressor in pancreatic cancer.

PubMed

Lahdaoui, F; Delpu, Y; Vincent, A; Renaud, F; Messager, M; Duchêne, B; Leteurtre, E; Mariette, C; Torrisani, J; Jonckheere, N; Van Seuningen, I

2015-02-05

Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal cancers in the world with one of the worst outcome. The oncogenic mucin MUC4 has been identified as an actor of pancreatic carcinogenesis as it is involved in many processes regulating pancreatic cancer cell biology. MUC4 is not expressed in healthy pancreas whereas it is expressed very early in pancreatic carcinogenesis. Targeting MUC4 in these early steps may thus appear as a promising strategy to slow-down pancreatic tumorigenesis. miRNA negative regulation of MUC4 could be one mechanism to efficiently downregulate MUC4 gene expression in early pancreatic neoplastic lesions. Using in silico studies, we found two putative binding sites for miR-219-1-3p in the 3'-UTR of MUC4 and showed that miR-219-1-3p expression is downregulated both in PDAC-derived cell lines and human PDAC tissues compared with their normal counterparts. We then showed that miR-219-1-3p negatively regulates MUC4 mucin expression via its direct binding to MUC4 3'-UTR. MiR-219-1-3p overexpression (transient and stable) in pancreatic cancer cell lines induced a decrease of cell proliferation associated with a decrease of cyclin D1 and a decrease of Akt and Erk pathway activation. MiR-219-1-3p overexpression also decreased cell migration. Furthermore, miR-219-1-3p expression was found to be conversely correlated with Muc4 expression in early pancreatic intraepithelial neoplasia lesions of Pdx1-Cre;LSL-Kras(G12D) mice. Most interestingly, in vivo studies showed that miR-219-1-3p injection in xenografted pancreatic tumors in mice decreased both tumor growth and MUC4 mucin expression. Altogether, these results identify miR-219-1-3p as a new negative regulator of MUC4 oncomucin that possesses tumor-suppressor activity in PDAC.

[Expression of EP-CAM, beta-catenin in the carcinogenesis of squamous cell carcinoma of uterine cervix].

PubMed

Yang, Jian-zhu; Zhang, Xiang-hong; Wu, Wen-xin; Yan, Xia; Liu, Yan-li; Wang, Jun-ling; Wang, Feng-rong

2003-07-01

To study the expression of EP-CAM, beta-catenin in the carcinogenesis of squamous cell carcinoma of uterine cervix. The expressions of EP-CAM and beta-catenin were detected with immunohistochemical stain in 14 cases of normal cervical squamous epithelium, 32 cases of cervical intraepithelial neoplasia (CIN) and 38 cases of cervical invasive squamous cell carcinoma. The over-expression rates of EP-CAM were 0, 7.1%, 20.0%, 62.5% and 55.3% for normal cervical epithelium, CINI, CINII, CINIII and carcinoma groups. The EP-CAM over-expression rates in CINIII and cervical carcinoma groups were significantly higher than those in normal epithelium and CINI groups (P < 0.001). No aberrant expression of beta-catenin was shown in normal cervical epithelium, while the aberrant expression rates of beta-catenin in CINI, CINII, CINIII and cervical carcinoma group were 28.6%, 40.0%, 62.5% and 84.2%. The aberrant expression rate of beta-catenin increased with the increase in degree of CIN and development of cervical carcinoma. The over-expression rate of EP-CAM was reversely related to the differentiation of cervical squamous cell carcinoma (P < 0.001). EP-CAM and beta-catenin may be involved in the carcinogenesis of squamous cell carcinoma of uterine cervix. The over-expression of EP-CAM and aberrant expression of beta-catenin may serve as markers of squamous carcinogenesis of uterine cervix.

Effects of CASP5 gene overexpression on angiogenesis of HMEC-1 cells.

PubMed

Li, Haiyan; Li, Yuzhen; Cai, Limin; Bai, Bingxue; Wang, Yanhua

2015-01-01

The efficacy of gene overexpression of CASP5, a caspase family member, in angiogenesis in vitro and its mechanisms were clarified. Human full-length CASP5 gene was delivered into human microvascular endothelial HMEC-1 cells by recombinant lentivirus. The infection was estimated by green fluorescent protein. MTT method was used to analyze the efficacy of gene overexpression in cell proliferation ability, and Matrigel was used to estimate its effects in angiogenesis ability of cells. Meanwhile, Western blot was used to analyze the effects of CASP5 gene overexpression on the expression levels of angpt-1, angpt-2, Tie2 and VEGF-1 in the cells, which were signaling pathway factors related to angiogenesis. Recombinant lentivirus containing human full-length CASP5 gene was packed and purified successfully, with virus titer of 1×10(8) TU/ml. The recombinant lentivirus was used to infect HMEC-1 cells with MOI of 1, leading to a cell infection rate of 100%. There were no significant effects of CASP5 gene overexpression on both cell proliferation ability and the expression level of angpt-1. Meanwhile, expressions of angpt-2 and VEGF-1 were both enhanced, while Tie2 expression was inhibited. Results indicated that CASP5 gene overexpression promoted angiogenesis of HMEC-1 cells. CASP5 gene overexpression significantly promoted angiogenesis ability of HMEC-1 cells, which was probably achieved by inhibiting angpt-1/Tie2 and promoting VEGF-1 signal pathway.

Traffic safety for the cell: influence of cyclin-dependent kinase activity on genomic stability.

PubMed

Enders, Greg H; Maude, Shannon L

2006-04-12

Genomic instability has long been considered a key factor in tumorigenesis. Recent evidence suggests that DNA damage may be widespread in early pre-neoplastic states, with deregulation of cyclin-dependent kinase (Cdk) activity a driving force. Increased Cdk activity may critically reduce licensing of origins of DNA replication, drive re-replication, or mediate overexpression of checkpoint proteins, inducing deleterious cell cycle delay. Conversely, inhibition of Cdk activity may compromise replication efficiency, expression of checkpoint proteins, or activation of DNA repair proteins. These vital functions point to the impact of Cdk activity on the stability of the genome. Insight into these pathways may improve our understanding of tumorigenesis and lead to more rational cancer therapies.

Steroid conversion with CYP106A2 – production of pharmaceutically interesting DHEA metabolites

PubMed Central

2014-01-01

Background Steroids are lipophilic compounds with a gonane skeleton and play an important role in higher organisms. Due to different functionalizations - mainly hydroxylations - at the steroid molecule, they vary highly in their mode of action. The pharmaceutical industry is, therefore, interested in hydroxysteroids as therapeutic agents. The insertion of hydroxyl groups into a steroid core, however, is hardly accomplishable by classical chemical means; that is because microbial steroid hydroxylations are investigated and applied since decades. CYP106A2 is a cytochrome P450 monooxygenase from Bacillus megaterium ATCC 13368, which was first described in the late 1970s and which is capable to hydroxylate a variety of 3-oxo-delta4 steroids at position 15beta. CYP106A2 is a soluble protein, easy to express and to purify in high amounts, which makes this enzyme an interesting target for biotechnological purposes. Results In this work a focused steroid library was screened in vitro for new CYP106A2 substrates using a reconstituted enzyme assay. Five new substrates were identified, including dehydroepiandrosterone and pregnenolone. NMR-spectroscopy revealed that both steroids are mainly hydroxylated at position 7beta. In order to establish a biotechnological system for the preparative scale production of 7beta-hydroxylated dehydroepiandrosterone, whole-cell conversions with growing and resting cells of B. megaterium ATCC1336 the native host of CYP1062 and also with resting cells of a recombinant B. megaterium MS941 strain overexpressing CYP106A2 have been conducted and conversion rates of 400 muM/h (115 mg/l/h) were obtained. Using the B. megaterium MS941 overexpression strain, the selectivity of the reaction was improved from 0.7 to 0.9 for 7beta-OH-DHEA. Conclusions In this work we describe CYP106A2 for the first time as a regio-selective hydroxylase for 3-hydroxy-delta5 steroids. DHEA was shown to be converted to 7beta-OH-DHEA which is a highly interesting human metabolite, supposed to act as neuroprotective, anti-inflammatory and immune-modulatory agent. Optimization of the whole-cell system using different B. megaterium strains lead to a conversion of DHEA with B. megaterium showing high selectivity and conversion rates and displaying a volumetric yield of 103 mg/l/h 7beta-OH-DHEA. PMID:24903845

Steroid conversion with CYP106A2 - production of pharmaceutically interesting DHEA metabolites.

PubMed

Schmitz, Daniela; Zapp, Josef; Bernhardt, Rita

2014-06-05

Steroids are lipophilic compounds with a gonane skeleton and play an important role in higher organisms. Due to different functionalizations - mainly hydroxylations - at the steroid molecule, they vary highly in their mode of action. The pharmaceutical industry is, therefore, interested in hydroxysteroids as therapeutic agents. The insertion of hydroxyl groups into a steroid core, however, is hardly accomplishable by classical chemical means; that is because microbial steroid hydroxylations are investigated and applied since decades. CYP106A2 is a cytochrome P450 monooxygenase from Bacillus megaterium ATCC 13368, which was first described in the late 1970s and which is capable to hydroxylate a variety of 3-oxo-delta4 steroids at position 15beta. CYP106A2 is a soluble protein, easy to express and to purify in high amounts, which makes this enzyme an interesting target for biotechnological purposes. In this work a focused steroid library was screened in vitro for new CYP106A2 substrates using a reconstituted enzyme assay. Five new substrates were identified, including dehydroepiandrosterone and pregnenolone. NMR-spectroscopy revealed that both steroids are mainly hydroxylated at position 7beta. In order to establish a biotechnological system for the preparative scale production of 7beta-hydroxylated dehydroepiandrosterone, whole-cell conversions with growing and resting cells of B. megaterium ATCC1336 the native host of CYP1062 and also with resting cells of a recombinant B. megaterium MS941 strain overexpressing CYP106A2 have been conducted and conversion rates of 400 muM/h (115 mg/l/h) were obtained. Using the B. megaterium MS941 overexpression strain, the selectivity of the reaction was improved from 0.7 to 0.9 for 7beta-OH-DHEA. In this work we describe CYP106A2 for the first time as a regio-selective hydroxylase for 3-hydroxy-delta5 steroids. DHEA was shown to be converted to 7beta-OH-DHEA which is a highly interesting human metabolite, supposed to act as neuroprotective, anti-inflammatory and immune-modulatory agent. Optimization of the whole-cell system using different B. megaterium strains lead to a conversion of DHEA with B. megaterium showing high selectivity and conversion rates and displaying a volumetric yield of 103 mg/l/h 7beta-OH-DHEA.

[Overexpression of LaeA enhances mevastatin production and reduces sporulation of Penicillium citrinum].

PubMed

Zheng, Yueliang; Cao, Shuang; Huang, Yuqi; Liao, Guojian; Hu, Changhua

2014-12-04

To study the regulation of laeA overexpression on mevastatin production and sporulation in Penicillium citrinum. We cloned the laeA gene from Penicillium citrinum and constructed the vector pGiHTGi-laeA. The plasmid pGiHTGi-laeA was transformed in Penicillium citrinum by agrobacterium tumefaciens-mediated transformation. Positive transformants were detected by cloning the hygromycin gene. The mevastatin production of the wild type and OE:: laeA was compared by HPLC. The conidia number was counted by blood counting chamber. The biosynthetic gene cluster expression quantity of mevastatin in the wild type and OE: :laeA were analyzed by qRT-PCR. We constructed the plasmid pGiHTGi-laeA, and screened the positive transformants that overexpress the laeA in Penicillium citrinum. With the overexpression of laeA, the mevastatin production was increased from (0.69 ± 0.12) mg/g to (4.02 ± 0.50) mg/g dry cell weight. Compared to the wild type strain, the laeA expression quantity in the OE :: laeA strain increased 29%, and the mlcB expression increased 72%, the mlcR expression increased 153%. Moreover, the overexpression of laeA would decrease the conidia number. Overexpression of LaeA enhances mevastatin production and reduces sporulation of Penicillium citrinum, with increases expression of pathway-regulator mlcR, and biosynthetic gene MlcR. These results could guide global regulatory mechanism of mevastatin biosynthesis and the exploitation of high-production strain.

Overexpression of an Arabidopsis heterogeneous nuclear ribonucleoprotein gene, AtRNP1, affects plant growth and reduces plant tolerance to drought and salt stresses

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

Wang, Zhenyu, E-mail: wzy72609@163.com; Zhao, Xiuyang, E-mail: xiuzh@psb.vib-ugent.be; Wang, Bing, E-mail: wangbing@ibcas.ac.cn

Heterogeneous nuclear ribonucleoproteins (hnRNPs) participate in diverse regulations of plant growth and environmental stress responses. In this work, an Arabidopsis hnRNP of unknown function, AtRNP1, was investigated. We found that AtRNP1 gene is highly expressed in rosette and cauline leaves, and slightly induced under drought, salt, osmotic and ABA stresses. AtRNP1 protein is localized to both the nucleus and cytoplasm. We performed homologous overexpression of AtRNP1 and found that the transgenic plants showed shortened root length and plant height, and accelerated flowering. In addition, the transgenic plants also showed reduced tolerance to drought, salt, osmotic and ABA stresses. Further studiesmore » revealed that under both normal and stress conditions, the proline contents in the transgenic plants are markedly decreased, associated with reduced expression levels of a proline synthase gene and several stress-responsive genes. These results suggested that the overexpression of AtRNP1 negatively affects plant growth and abiotic stress tolerance. - Highlights: • AtRNP1 is a widely expressed gene and its expression is slightly induced under abiotic stresses. • AtRNP1 protein is localized to both the nucleus and cytoplasm. • Overexpression of AtRNP1 affects plant growth. • Overexpression of AtRNP1 reduces plant tolerance to drought and salt stresses. • AtRNP1 overexpression plants show decreased proline accumulation and stress-responsive gene expressions.« less

CCNG2 Overexpression Mediated by AKT Inhibits Tumor Cell Proliferation in Human Astrocytoma Cells.

PubMed

Zhang, Danfeng; Wang, Chunhui; Li, Zhenxing; Li, Yiming; Dai, Dawei; Han, Kaiwei; Lv, Liquan; Lu, Yicheng; Hou, Lijun; Wang, Junyu

2018-01-01

The cyclin family protein CCNG2 has an important inhibitory role in cancer initiation and progression, but the exact mechanism is still unknown. In this study, we examined the relationship between CCNG2 and the malignancy of astrocytomas and whether the AKT pathway, which is upregulated in astrocytomas, may inhibit CCNG2 expression. CCNG2 expression was found to be negatively associated with the pathological grade and proliferative activity of astrocytomas, as the highest expression was found in control brain tissue ( N  = 31), whereas the lowest expression was in high-grade glioma tissue ( N  = 31). Additionally, CCNG2 overexpression in glioma cell lines, T98G and U251 inhibited proliferation and arrested cells in the G0/G1 phase. Moreover, CCNG2 overexpression could increase glioma cells apoptosis. In contrast, AKT activity increased in glioma cells that had low CCNG2 expression. Expression of CCNG2 was higher in cells treated with the AKT kinase inhibitor MK-2206 indicating that the presence of phosphorylated AKT may inhibit the expression of CCNG2. Inhibition of AKT also led to decreased colony formation in T98G and U251 cells and knocked down of CCNG2 reversed the result. Finally, overexpression of CCNG2 in glioma cells reduced tumor volume in a murine model. To conclude, low expression of CCNG2 correlated with the severity astrocytoma and CCNG2 overexpression could induce apoptosis and inhibit proliferation. Inhibition of AKT activity increased the expression of CCNG2. The present study highlights the regulatory consequences of CCNG2 expression and AKT activity in astrocytoma tumorigenesis and the potential use of CCNG2 in anticancer treatment.

A missing link between RON expression and oncological outcomes in resected left-sided pancreatic cancer.

PubMed

Han, Dai Hoon; Kang, Chang Moo; Lee, Sung Whan; Hwang, Ho Kyoung; Lee, Woo Jung

2017-10-01

Alteration and activation of recepteur d'origine nantais (RON) expression is known to be associated with cancer progression and decreased survival in various types of human cancer, including pancreatic cancer. Therefore, in the present study, RON expression levels were determined in resected left-sided pancreatic cancer to evaluate the potential oncological role of RON in the clinical setting of distal pancreatic cancer. From January 2005 to December 2011, a total of 57 patients underwent radical distal pancreatectomy for left-sided pancreatic cancer. Ductal adenocarcinoma was confirmed in all patients. Among these patients, 17 patients who received preoperative neoadjuvant treatment and 7 patients without available paraffin-embedded tissue blocks were excluded from the present study. RON expression in a the pancreatic cancer cell lines ASPC-1, BxPC-3, MiaPaCa-3 and Panc-1, as well as in resected left-sided pancreatic cancer specimens was determined by Western blot analysis. RON and vascular endothelial growth factor (VEGF) overexpression in resected left-sided pancreatic cancer was also evaluated by immunohistochemistry using pre-diluted anti-RON and anti-VEGF antibodies. An association was identified between the oncological outcome and RON overexpression. Increased levels of RON expression were observed in two pancreatic cancer cell lines, AsPC-1 and BxPC-3. RON overexpression was detected in specimens from 15/33 patients (45.5%) using immunohistochemistry. No significant association was identified between RON overexpression and VEGF overexpression (25.5 vs. 87.9%; P=0.667). No significant differences in disease-free survival or disease-specific survival associated with RON overexpression were identified. Although the results of previous studies have suggested that RON is a potential target for the treatment of pancreatic cancer, in the present study no association between RON overexpression and any adverse oncological effect was identified.

Hepatitis C virus core protein induces hepatic steatosis via Sirt1-dependent pathway.

PubMed

Zhang, Chuanhai; Wang, Jingjing; Zhang, Hanlin; Liu, Shunai; Lee, Hyuek Jong; Jin, Wanzhu; Cheng, Jun

2018-05-01

Hepatic steatosis is a common feature of patients with chronic hepatitis C. Previous reports have shown that the overexpression of hepatitis C virus core-encoding sequences (hepatitis C virus genotypes 3a and 1b) significantly induces intracellular triglyceride accumulation. However, the underlying mechanism has not yet been revealed. To investigate whether Sirt1 is involved in hepatitis C virus-mediated hepatic steatosis, the overexpression of hepatitis C virus core 1b protein and Sirt1 and the knockdown of Sirt1 in HepG2 cells were performed. To confirm the results of the cellular experiment liver-specific Sirt1 KO mice with lentivirus-mediated hepatitis C virus core 1b overexpression were studied. Our results show that hepatitis C virus core 1b protein overexpression led to the accumulation of triglycerides in HepG2 cells. Notably the expression of PPARγ2 was dramatically increased at both the mRNA and protein levels by hepatitis C virus core 1b overexpression. The protein expression of Sirt1 is an upstream regulator of PPARγ2 and was also significantly increased after core 1b overexpression. In addition, the overexpression or knockdown of Sirt1 expression alone was sufficient to modulate p300-mediated PPARγ2 deacetylation. In vivo studies showed that hepatitis C virus core protein 1b-induced hepatic steatosis was attenuated in liver-specific Sirt1 KO mice by downregulation of PPARγ2 expression. Sirt1 mediates hepatitis C virus core protein 1b-induced hepatic steatosis by regulation of PPARγ2 expression. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Tetracycline-inducible system for regulation of skeletal muscle-specific gene expression in transgenic mice

NASA Technical Reports Server (NTRS)

Grill, Mischala A.; Bales, Mark A.; Fought, Amber N.; Rosburg, Kristopher C.; Munger, Stephanie J.; Antin, Parker B.

2003-01-01

Tightly regulated control of over-expression is often necessary to study one aspect or time point of gene function and, in transgenesis, may help to avoid lethal effects and complications caused by ubiquitous over-expression. We have utilized the benefits of an optimized tet-on system and a modified muscle creatine kinase (MCK) promoter to generate a skeletal muscle-specific, doxycycline (Dox) controlled over-expression system in transgenic mice. A DNA construct was generated in which the codon optimized reverse tetracycline transactivator (rtTA) was placed under control of a skeletal muscle-specific version of the mouse MCK promoter. Transgenic mice containing this construct expressed rtTA almost exclusively in skeletal muscles. These mice were crossed to a second transgenic line containing a bi-directional promoter centered on a tet responder element driving both a luciferase reporter gene and a tagged gene of interest; in this case the calpain inhibitor calpastatin. Compound hemizygous mice showed high level, Dox dependent muscle-specific luciferase activity often exceeding 10,000-fold over non-muscle tissues of the same mouse. Western and immunocytochemical analysis demonstrated similar Dox dependent muscle-specific induction of the tagged calpastatin protein. These findings demonstrate the effectiveness and flexibility of the tet-on system to provide a tightly regulated over-expression system in adult skeletal muscle. The MCKrtTA transgenic lines can be combined with other transgenic responder lines for skeletal muscle-specific over-expression of any target gene of interest.

Epigallocatechin-3-gallate suppressed the over-expression of HSP 70 and MDR1 induced by heat shock in SGC 7901.

PubMed

Tang, Xiao-Yan; Zhu, You-Qing

2008-06-01

This study investigated the effects of epigallocatechin-3-gallate (EGCG) on the expression of HSP 70 and MDR 1. SGC-7901 cells were cultured with RPMI 1640 medium. The single or combined effects of EGCG (0.1, 1, 10, 20, and 40 micromol/L) and heat shock were examined by MTT assay. The expression of HSP 70 and MDR 1 was semi-quantified by the reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry method (SP staining). EGCG suppressed cell proliferation at a time- and dose-dependent manner. The effects of combined treatment with EGCG and heat shock on the growth of SGC-7901 cells were stronger than single effects of EGCG. After using EGCG for 24 h, 48 h and 72 h, the IC50s were 112.5 micromol/l, 21.41 micromol/l and 5.24 micromol/l, respectively. Heat shock stimulated the over-expression of HSP 70, especially after heat shock for 8 h, as well as MDR1 after heat shock for 24 h. But EGCG suppressed the over-expression induced by heat shock. The authors conclude that EGCG inhibited the proliferation of SGC-7901, and EGCG combined with heat shock strengthened the effects. Heat shock weakened the over-expression of HSP 70 and MDR1; however, EGCG suppressed the over-expression of HSP 70 and MDR1 induced by heat shock. EGCG combined with heat shock may enhance the sensitivity of drugs to tumors.

Distance between RBS and AUG plays an important role in overexpression of recombinant proteins.

PubMed

Berwal, Sunil K; Sreejith, R K; Pal, Jayanta K

2010-10-15

The spacing between ribosome binding site (RBS) and AUG is crucial for efficient overexpression of genes when cloned in prokaryotic expression vectors. We undertook a brief study on the overexpression of genes cloned in Escherichia coli expression vectors, wherein the spacing between the RBS and the start codon was varied. SDS-PAGE and Western blot analysis indicated a high level of protein expression only in constructs where the spacing between RBS and AUG was approximately 40 nucleotides or more, despite the synthesis of the transcripts in the representative cases investigated. Copyright 2010 Elsevier Inc. All rights reserved.

Over-expression in Escherichia coli and characterization of two recombinant isoforms of human FAD synthetase

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

Brizio, Carmen; Galluccio, Michele; Wait, Robin

2006-06-09

FAD synthetase (FADS) (EC 2.7.7.2) is a key enzyme in the metabolic pathway that converts riboflavin into the redox cofactor FAD. Two hypothetical human FADSs, which are the products of FLAD1 gene, were over-expressed in Escherichia coli and identified by ESI-MS/MS. Isoform 1 was over-expressed as a T7-tagged protein which had a molecular mass of 63 kDa on SDS-PAGE. Isoform 2 was over-expressed as a 6-His-tagged fusion protein, carrying an extra 84 amino acids at the N-terminal with an apparent molecular mass of 60 kDa on SDS-PAGE. It was purified near to homogeneity from the soluble cell fraction by one-stepmore » affinity chromatography. Both isoforms possessed FADS activity and had a strict requirement for MgCl{sub 2}, as demonstrated using both spectrophotometric and chromatographic methods. The purified recombinant isoform 2 showed a specific activity of 6.8 {+-} 1.3 nmol of FAD synthesized/min/mg protein and exhibited a K {sub M} value for FMN of 1.5 {+-} 0.3 {mu}M. This is First report on characterization of human FADS, and First cloning and over-expression of FADS from an organism higher than yeast.« less

The Clinical Impact of c-MET Over-Expression in Advanced Biliary Tract Cancer (BTC).

PubMed

Heo, Mi Hwa; Kim, Hee Kyung; Lee, Hansang; Kim, Kyoung-Mee; Lee, Jeeyun; Park, Se Hoon; Park, Joon Oh; Lim, Ho Yeong; Kang, Won Ki; Park, Young Suk; Kim, Seung Tae

2017-01-01

Background : c-MET is a proto-oncogene that encodes the tyrosine kinase receptor for hepatocyte growth factor (HGF). Activation of HGF-c-MET signaling involves cell invasiveness and evokes metastasis through direct involvement of tumor angiogenesis. However, the value of c-MET overexpression is still unknown in metastatic biliary tract cancer (BTC). Methods : We analyzed the incidence and clinicopathologic characteristics of c-MET overexpression in advanced BTC. Moreover, we investigated the value of c-MET overexpression in predicting response to gemicitabine plus cisplatin (GC), a first line standard regimen, and as a prognostic marker in metastatic BTC. Results : The BTC subtype distribution (N=44) was as follows: intrahepatic cholangiocarcinoma (IHCC, n=7), extrahepatic cholangiocarcinoma (EHCC, n=25) and gallbladder cancer (GBC, n=12). Liver (52.3%) was the predominant metastatic site, followed by lymph nodes (36.4%) and bone (15.9%). Among the 44 patients analyzed for c-MET expression, 15 (34.1%) exhibited c-MET overexpression in tumor tissues. There was no significant difference in the prevalence of c-MET overexpression among primary sites in EHCC (7/25, 28.0%), IHCC (3/7, 42.9%), and GBC (5/12, 41.7%). There was also no significant correlation between specific clinicopathologic variables and c-MET expression. Comparing the tumor-response to GC according to c-MET expression (overexpression vs. non-overexpression), there was no significant difference in either RR or DCR (p=0.394 and p >0.999, respectively). The median PFS for all 44 patients was 9.00 months (95% CI, 7.5-10.5 months) and there was no significant difference for PFS between patients with c-MET overexpression and those without (p=0.917). The median OS was 14.4 months (95% CI, 11.9-16.9 months). There was no significant difference in OS between patients with c-MET overexpression compared to those without (13.7 vs. 14.4 months, respectively; p=0.708). Conclusions : c-MET overexpression was detected in 34.1% of advanced BTC patients irrespective of tumor location. c-MET overexpression did not predict response to GC or survival. Further studies are needed to fully elucidate the value of c-MET overexpression as a novel biomarker in these patients.

Overexpression of the cholesterol-binding protein MLN64 induces liver damage in the mouse

PubMed Central

Tichauer, Juan Enrique; Morales, María Gabriela; Amigo, Ludwig; Galdames, Leopoldo; Klein, Andrés; Quiñones, Verónica; Ferrada, Carla; R, Alejandra Alvarez; Rio, Marie-Christine; Miquel, Juan Francisco; Rigotti, Attilio; Zanlungo, Silvana

2007-01-01

AIM: To examine the in vivo phenotype associated with hepatic metastatic lymph node 64 (MLN64) over-expression. METHODS: Recombinant-adenovirus-mediated MLN64 gene transfer was used to overexpress MLN64 in the livers of C57BL/6 mice. We measured the effects of MLN64 overexpression on hepatic cholesterol content, bile flow, biliary lipid secretion and apoptosis markers. For in vitro studies cultured CHO cells with transient MLN64 overexpression were utilized and apoptosis by TUNEL assay was measured. RESULTS: Livers from Ad.MLN64-infected mice exhibited early onset of liver damage and apoptosis. This response correlated with increases in liver cholesterol content and biliary bile acid concentration, and impaired bile flow. We investigated whether liver MLN64 expression could be modulated in a murine model of hepatic injury. We found increased hepatic MLN64 mRNA and protein levels in mice with chenodeoxycholic acid-induced liver damage. In addition, cultured CHO cells with transient MLN64 overexpression showed increased apoptosis. CONCLUSION: In summary, hepatic MLN64 over-expression induced damage and apoptosis in murine livers and altered cholesterol metabolism. Further studies are required to elucidate the relevance of these findings under physiologic and disease conditions. PMID:17589922

Pleiotrophin over-expression provides trophic support to dopaminergic neurons in parkinsonian rats.

PubMed

Taravini, Irene Re; Chertoff, Mariela; Cafferata, Eduardo G; Courty, José; Murer, Mario G; Pitossi, Fernando J; Gershanik, Oscar S

2011-06-07

Pleiotrophin is known to promote the survival and differentiation of dopaminergic neurons in vitro and is up-regulated in the substantia nigra of Parkinson's disease patients. To establish whether pleiotrophin has a trophic effect on nigrostriatal dopaminergic neurons in vivo, we injected a recombinant adenovirus expressing pleiotrophin in the substantia nigra of 6-hydroxydopamine lesioned rats. The viral vector induced pleiotrophin over-expression by astrocytes in the substantia nigra pars compacta, without modifying endogenous neuronal expression. The percentage of tyrosine hydroxylase-immunoreactive cells as well as the area of their projections in the lesioned striatum was higher in pleiotrophin-treated animals than in controls. These results indicate that pleiotrophin over-expression partially rescues tyrosine hydroxylase-immunoreactive cell bodies and terminals of dopaminergic neurons undergoing 6-hydroxydopamine-induced degeneration.

MUC4 stabilizes HER2 expression and maintains the cancer stem cell population in ovarian cancer cells.

PubMed

Ponnusamy, Moorthy P; Seshacharyulu, Parthasarathy; Vaz, Arokiapriyanka; Dey, Parama; Batra, Surinder K

2011-04-26

Recent evidence has suggested that the capability of cancer to grow, propagate and relapse after therapy is dependent on a small subset of the cell population within the tumor, called cancer stem cells. Therefore, this subpopulation of cells needs to be targeted with different approaches by identification of unique stem-cell specific target antigens. One of the well known tumor antigens is the epithelial cell mucin MUC4, which is aberrantly expressed in ovarian cancer as compared to the normal ovary and plays a pivotal role in the aggressiveness and metastasis of ovarian cancer cells. In the present study, we aimed to analyze the cancer stem cell population in MUC4 overexpressed ovarian cancer cells. MUC4 was ectopically overexpressed in SKOV3 ovarian cancer cells. Western blot analysis was performed for MUC4, HER2, CD133, ALDH1 and Shh expression in MUC4 overexpressed cells. Confocal analysis of MUC4, HER2 and CD133 was also done in the MUC4 overexpressed cells. CD133 and Hoechst33342 dye staining was used to analyze the cancer stem cell population via FACS method in SKOV3-MUC4 cells. MUC4 overexpressed SKOV3 cells showed an increased expression of HER2 compared to control cells. MUC4 overexpression leads to increased (0.1%) side population (SP) and CD133-positive cancer stem cells compared to the control cells. Interestingly, the tumor sphere type circular colony formation was observed only in the MUC4 overexpressed ovarian cancer cells. Furthermore, the cancer stem cell marker CD133 was expressed along with MUC4 in the isolated circular colonies as analyzed by both confocal and western blot analysis. HER2 and cancer stem cell specific marker ALDH1 along with Shh, a self-renewal marker, showed increased expression in the isolated circular colonies compared to MUC4-transfected cells. These studies demonstrate that MUC4 overexpression leads to an enriched ovarian cancer stem cell population either directly or indirectly through HER2. In future, this study would be helpful for MUC4-directed therapy for the ovarian cancer stem cell population.

MUC4 stabilizes HER2 expression and maintains the cancer stem cell population in ovarian cancer cells

PubMed Central

2011-01-01

Background Recent evidence has suggested that the capability of cancer to grow, propagate and relapse after therapy is dependent on a small subset of the cell population within the tumor, called cancer stem cells. Therefore, this subpopulation of cells needs to be targeted with different approaches by identification of unique stem-cell specific target antigens. One of the well known tumor antigens is the epithelial cell mucin MUC4, which is aberrantly expressed in ovarian cancer as compared to the normal ovary and plays a pivotal role in the aggressiveness and metastasis of ovarian cancer cells. In the present study, we aimed to analyze the cancer stem cell population in MUC4 overexpressed ovarian cancer cells. Methods MUC4 was ectopically overexpressed in SKOV3 ovarian cancer cells. Western blot analysis was performed for MUC4, HER2, CD133, ALDH1 and Shh expression in MUC4 overexpressed cells. Confocal analysis of MUC4, HER2 and CD133 was also done in the MUC4 overexpressed cells. CD133 and Hoechst33342 dye staining was used to analyze the cancer stem cell population via FACS method in SKOV3-MUC4 cells. Results MUC4 overexpressed SKOV3 cells showed an increased expression of HER2 compared to control cells. MUC4 overexpression leads to increased (0.1%) side population (SP) and CD133-positive cancer stem cells compared to the control cells. Interestingly, the tumor sphere type circular colony formation was observed only in the MUC4 overexpressed ovarian cancer cells. Furthermore, the cancer stem cell marker CD133 was expressed along with MUC4 in the isolated circular colonies as analyzed by both confocal and western blot analysis. HER2 and cancer stem cell specific marker ALDH1 along with Shh, a self-renewal marker, showed increased expression in the isolated circular colonies compared to MUC4-transfected cells. Conclusion These studies demonstrate that MUC4 overexpression leads to an enriched ovarian cancer stem cell population either directly or indirectly through HER2. In future, this study would be helpful for MUC4-directed therapy for the ovarian cancer stem cell population. PMID:21521521

Calreticulin Regulates VEGF-A in Neuroblastoma Cells.

PubMed

Weng, Wen-Chin; Lin, Kuan-Hung; Wu, Pei-Yi; Lu, Yi-Chien; Weng, Yi-Cheng; Wang, Bo-Jeng; Liao, Yung-Feng; Hsu, Wen-Ming; Lee, Wang-Tso; Lee, Hsinyu

2015-08-01

Calreticulin (CRT) has been previously correlated with the differentiation of neuroblastoma (NB), implying a favorable prognostic factor. Vascular endothelial growth factor (VEGF) has been reported to participate in the behavior of NB. This study investigated the association of CRT and VEGF-A in NB cells. The expressions of VEGF-A and HIF-1α, with overexpression or knockdown of CRT, were measured in three NB cells (SH-SY5Y, SK-N-DZ, and stNB-V1). An inducible CRT NB cell line and knockdown CRT stable cell lines were also established. The impacts of CRT overexpression on NB cell apoptosis, proliferation, and differentiation were also evaluated. We further examined the role of VEGF-A in the NB cell differentiation via VEGF receptor blockade. Constitutive overexpression of CRT led to NB cell differentiation without proliferation. Thus, an inducible CRT stNB-V1 cell line was generated by a tetracycline-regulated gene system. CRT overexpression increased VEGF-A and HIF-1α messenger RNA (mRNA) expressions in SH-SY5Y, SK-N-DZ, and stNB-V1 cells. CRT overexpression also enhanced VEGF-A protein expression and secretion level in conditioned media in different NB cell lines. Knockdown of CRT decreased VEGF-A and HIF-1α mRNA expressions and lowered VEGF-A protein expression and secretion level in conditioned media in different NB cell lines. We further demonstrated that NB cell apoptosis was not affected by CRT overexpression in stNB-V1 cells. Nevertheless, overexpression of CRT suppressed cell proliferation and enhanced cell differentiation in stNB-V1 cells, whereas blockage of VEGFR-1 markedly suppressed the expression of neuron-specific markers including GAP43, NSE2, and NFH, as well as TrkA, a molecular marker indicative of NB cell differentiation. Our findings suggest that VEGF-A is involved in CRT-related neuronal differentiation in NB. Our work may provide important information for developing a new therapeutic strategy to improve the outcome of NB patients.

H3K9ac and HDAC2 Activity Are Involved in the Expression of Monocarboxylate Transporter 1 in Oligodendrocyte

PubMed Central

Lai, Qingwei; Du, Wantong; Wu, Jian; Wang, Xiao; Li, Xinyu; Qu, Xuebin; Wu, Xiuxiang; Dong, Fuxing; Yao, Ruiqin; Fan, Hongbin

2017-01-01

Recently, it is reported that monocarboxylate transporter 1 (MCT1) plays crucial role in oligodendrocyte differentiation and myelination. We found that MCT1 is strongly expressed in oligodendrocyte but weakly expressed in oligodendrocyte precursors (OPCs), and the underlying mechanisms remain elusive. Histone deacetylases (HDACs) activity is required for induction of oligodendrocyte differentiation and maturation. We asked whether HDACs are involved in the regulation of MCT1 expression. This work revealed that the acetylation level of histone H3K9 (H3K9ac) was much higher in mct1 gene (Slc16a1) promoter in OPCs than that in oligodendrocyte. H3K9ac regulates MCT1 expression was confirmed by HDAC acetyltransferase inhibitors trichostatin A and curcumin. Of note, there was a negative correlation between H3K9ac and MCT1 expression in oligodendrocyte. Further, we found that the levels of HDAC1, 2, and 3 protein in oligodendrocyte were obviously higher than those in OPCs. However, specific knockdown of HDAC2 but not HDAC1 and HDAC3 significantly decreased the expression of MCT1 in oligodendrocyte. Conversely, overexpression of HDAC2 remarkably enhanced the expression of MCT1. The results imply that HDAC2 is involved in H3K9ac modification which regulates the expression of MCT1 during the development of oligodendrocyte. PMID:29184483

Transcriptional regulation of an insulin-sensitizing adipokine adipolin/CTRP12 in adipocytes by Krüppel-like factor 15.

PubMed

Enomoto, Takashi; Ohashi, Koji; Shibata, Rei; Kambara, Takahiro; Uemura, Yusuke; Yuasa, Daisuke; Kataoka, Yoshiyuki; Miyabe, Megumi; Matsuo, Kazuhiro; Joki, Yusuke; Hayakawa, Satoko; Hiramatsu-Ito, Mizuho; Ito, Masanori; Murohara, Toyoaki; Ouchi, Noriyuki

2013-01-01

Obese states characterized by chronic inflammation are closely linked to the development of metabolic dysfunction. We identified adipolin/CTRP12 as an insulin-sensitizing and anti-inflammatory adipokine. Although obese conditions down-regulate adipolin expression, its molecular mechanism is largely unknown. Here we show that the transcriptional regulator Krüppel-like factor (KLF) 15 is involved in the regulation of adipolin expression in adipocytes. White adipose tissue from diet-induced obese (DIO) mice showed decreased expression of KLF9 and KLF15 among several KLFs, which was accompanied by reduced expression of adipolin. In cultured 3T3L1 adipocytes, treatment with TNFα significantly reduced the mRNA levels of KLF9, KLF15 and adipolin. Adenovirus-mediated overexpression of KLF15 but not KLF9 reversed TNFα-induced reduction of adipolin expression in adipocytes. Conversely, gene targeting ablation of KLF15 attenuated adipolin expression in adipocytes. Expression of KLF15 but not KLF9 enhanced the promoter activity of adipolin in HEK293 cells. Pretreatment of 3T3L1 adipocytes with the JNK inhibitor SP600125, but not p38 MAPK inhibitor SB203580 blocked the inhibitory effects of TNFα on adipolin and KLF15 expression. These data suggest that adipose inflammation under conditions of obesity suppresses adipolin expression via JNK-dependent down-regulation of KLF15 in adipocytes.

Transcriptional Regulation of an Insulin-Sensitizing Adipokine Adipolin/CTRP12 in Adipocytes by Krüppel-Like Factor 15

PubMed Central

Enomoto, Takashi; Ohashi, Koji; Shibata, Rei; Kambara, Takahiro; Uemura, Yusuke; Yuasa, Daisuke; Kataoka, Yoshiyuki; Miyabe, Megumi; Matsuo, Kazuhiro; Joki, Yusuke; Hayakawa, Satoko; Hiramatsu-Ito, Mizuho; Ito, Masanori; Murohara, Toyoaki; Ouchi, Noriyuki

2013-01-01

Obese states characterized by chronic inflammation are closely linked to the development of metabolic dysfunction. We identified adipolin/CTRP12 as an insulin-sensitizing and anti-inflammatory adipokine. Although obese conditions down-regulate adipolin expression, its molecular mechanism is largely unknown. Here we show that the transcriptional regulator Krüppel-like factor (KLF) 15 is involved in the regulation of adipolin expression in adipocytes. White adipose tissue from diet-induced obese (DIO) mice showed decreased expression of KLF9 and KLF15 among several KLFs, which was accompanied by reduced expression of adipolin. In cultured 3T3L1 adipocytes, treatment with TNFα significantly reduced the mRNA levels of KLF9, KLF15 and adipolin. Adenovirus-mediated overexpression of KLF15 but not KLF9 reversed TNFα-induced reduction of adipolin expression in adipocytes. Conversely, gene targeting ablation of KLF15 attenuated adipolin expression in adipocytes. Expression of KLF15 but not KLF9 enhanced the promoter activity of adipolin in HEK293 cells. Pretreatment of 3T3L1 adipocytes with the JNK inhibitor SP600125, but not p38 MAPK inhibitor SB203580 blocked the inhibitory effects of TNFα on adipolin and KLF15 expression. These data suggest that adipose inflammation under conditions of obesity suppresses adipolin expression via JNK-dependent down-regulation of KLF15 in adipocytes. PMID:24358263

Clinically relevant HIF-1α-dependent metabolic reprogramming in oropharyngeal squamous cell carcinomas includes coordinated activation of CAIX and the miR-210/ISCU signaling axis, but not MCT1 and MCT4 upregulation

PubMed Central

Sáenz-de-Santa-María, Inés; Bernardo-Castiñeira, Cristóbal; Secades, Pablo; Bernaldo-de-Quirós, Sandra; Rodrigo, Juan Pablo; Astudillo, Aurora; Chiara, María-Dolores

2017-01-01

Metabolic reprogramming is a very heterogeneous phenomenon in cancer. It mostly consists on increased glycolysis, lactic acid formation and extracellular acidification. These events have been associated to increased activity of the hypoxia inducible factor, HIF-1α. This study aimed at defining the metabolic program activated by HIF-1α in oropharyngeal squamous cell carcinomas (SCC) and assessing its clinical impact. Global gene/miRNA expression was analyzed in SCC-derived cells exposed to hypoxia. Expression of HIF-1α, the carbonic anhydrase CAIX, and the lactate/H+ transporters MCT1 and MCT4 were analyzed by immunohistochemistry in 246 SCCs. Cell-based analysis revealed that HIF-1α-driven metabolic program includes over-expression of glycolytic enzymes and the microRNA miR-210 coupled to down-regulation of its target, the iron-sulfur cluster assembly protein, ISCU. pH-regulator program entailed over-expression of CAIX, but not MCT1 or MCT4. Accordingly, significant overlapping exists between over-expression of HIF-1α and CAIX, but not HIF-1α and MCT1 or MCT4, in tumor cells. Increased miR-210 and concomitant decreased ISCU RNA levels were found in ~40% of tumors and this was significantly associated with HIF-1α and CAIX, but not MCT1 or MCT4, over-expression. HIF-1α and/or CAIX over-expression was associated with high recurrence rate and low overall survival of surgically treated patients. By contrast, clinically significant correlations were not found in tumors with MCT1 or MCT4 over-expression. This is the first study that provides in vivo evidences of coordinated activation of HIF-1α, CAIX, miR-210 and ISCU in carcinoma and association with poor prognosis, a finding with important implications for the development of metabolic-targeting therapies against hypoxia. PMID:28099149

Clinically relevant HIF-1α-dependent metabolic reprogramming in oropharyngeal squamous cell carcinomas includes coordinated activation of CAIX and the miR-210/ISCU signaling axis, but not MCT1 and MCT4 upregulation.

PubMed

Sáenz-de-Santa-María, Inés; Bernardo-Castiñeira, Cristóbal; Secades, Pablo; Bernaldo-de-Quirós, Sandra; Rodrigo, Juan Pablo; Astudillo, Aurora; Chiara, María-Dolores

2017-02-21

Metabolic reprogramming is a very heterogeneous phenomenon in cancer. It mostly consists on increased glycolysis, lactic acid formation and extracellular acidification. These events have been associated to increased activity of the hypoxia inducible factor, HIF-1α. This study aimed at defining the metabolic program activated by HIF-1α in oropharyngeal squamous cell carcinomas (SCC) and assessing its clinical impact. Global gene/miRNA expression was analyzed in SCC-derived cells exposed to hypoxia. Expression of HIF-1α, the carbonic anhydrase CAIX, and the lactate/H+ transporters MCT1 and MCT4 were analyzed by immunohistochemistry in 246 SCCs. Cell-based analysis revealed that HIF-1α-driven metabolic program includes over-expression of glycolytic enzymes and the microRNA miR-210 coupled to down-regulation of its target, the iron-sulfur cluster assembly protein, ISCU. pH-regulator program entailed over-expression of CAIX, but not MCT1 or MCT4. Accordingly, significant overlapping exists between over-expression of HIF-1α and CAIX, but not HIF-1α and MCT1 or MCT4, in tumor cells. Increased miR-210 and concomitant decreased ISCU RNA levels were found in ~40% of tumors and this was significantly associated with HIF-1α and CAIX, but not MCT1 or MCT4, over-expression. HIF-1α and/or CAIX over-expression was associated with high recurrence rate and low overall survival of surgically treated patients. By contrast, clinically significant correlations were not found in tumors with MCT1 or MCT4 over-expression. This is the first study that provides in vivo evidences of coordinated activation of HIF-1α, CAIX, miR-210 and ISCU in carcinoma and association with poor prognosis, a finding with important implications for the development of metabolic-targeting therapies against hypoxia.

Hand1 overexpression inhibits medulloblastoma metastasis

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

Asuthkar, Swapna; Guda, Maheedhara R.; Martin, Sarah E.

2016-08-19

Medulloblastoma (MB) is the most frequent malignant pediatric brain tumor. Current treatment includes surgery, radiation and chemotherapy. However, ongoing treatment in patients is further classified according to the presence or absence of metastasis. Since metastatic medulloblastoma are refractory to current treatments, there is need to identify novel biomarkers that could be used to reduce metastatic potential, and more importantly be targeted therapeutically. Previously, we showed that ionizing radiation-induced uPAR overexpression is associated with increased accumulation of β-catenin in the nucleus. We further demonstrated that uPAR protein act as cytoplasmic sequestration factor for a novel basic helix-loop-helix transcription factor, Hand1. Amongmore » the histological subtypes classical and desmoplastic subtypes account for the majority while large cell/anaplastic variant is most commonly associated with metastatic disease. In this present study using immunohistochemical approach and patient data mining for the first time, we demonstrated that Hand1 expression is observed to be downregulated in all the subtypes of medulloblastoma. Previously we showed that Hand1 overexpression regulated medulloblastoma angiogenesis and here we investigated the role of Hand1 in the context of Epithelial-Mesenchymal Transition (EMT). Moreover, UW228 and D283 cells overexpressing Hand1 demonstrated decreased-expression of mesenchymal markers (N-cadherin, β-catenin and SOX2); metastatic marker (SMA); and increased expression of epithelial marker (E-cadherin). Strikingly, human pluripotent stem cell antibody array showed that Hand1 overexpression resulted in substantial decrease in pluripotency markers (Nanog, Oct3/4, Otx2, Flk1) suggesting that Hand1 expression may be essential to attenuate the EMT and our findings underscore a novel role for Hand1 in medulloblastoma metastasis. - Highlights: • Hand1 expression is downregulated in Medulloblastoma. • Hand1 over expression reduce the expression of signaling from WNT, SHH and Group 3 medulloblastoma subgroups. • Hand1 overexpression reduced metastatic abilities by reducing the expression of β-catenin and N-cadherin.« less

Overexpression of microRNA-1288 in oesophageal squamous cell carcinoma.

PubMed

Gopalan, Vinod; Islam, Farhadul; Pillai, Suja; Tang, Johnny Cheuk-On; Tong, Daniel King-Hung; Law, Simon; Chan, Kwok-Wah; Lam, Alfred King-Yin

2016-11-01

This study aims to examine the expression profiles miR-1288 in oesophageal squamous cell carcinoma (ESCC). The cellular implications and target interactions of ESCC cells following miR-1288 overexpression was also examined. In total, 120 oesophageal tissues (90 primary ESCCs and 30 non-neoplastic tissues) were recruited for miR-1288 expression analysis using qRT-PCR. An exogenous miR-1288 mimic and its inhibitor were used to explore the in-vitro effects of miR-1288 on ESCC cells by performing cell proliferation, colony formation, cell invasion and migration assays. Localisation and modulatory changes of various miR-1288 regulated proteins such as FOXO1, p53, TAB3, BCL2 and kRAS was examined using immunofluorescence and western blot. Overexpression of miR-1288 was more often noted in ESCC tissues when compared to non-neoplastic oesophageal tissues. High expression was often noted in high grade carcinomas and with metastases. Patients with high levels of miR-1288 expression showed a slightly better survival compared to patients with low miR-1288 levels. Furthermore, overexpression of miR-1288 showed increased cell proliferation and colony formation, improved cell migration and enhanced cell invasion properties in ESCC cells. In addition, miR-1288 overexpression in ESCC cells showed repression of cytoplasmic tumour suppressor FOXO1 protein expression. Inversely, inhibition of miR-1288 expression exhibited remarkable upregulation of FOXO1 protein, while expressions of other tested proteins remain unchanged. Up regulation of miR-1288 expression in ESCC tissues and miR-1288 induced oncogenic features of ESCC cells in-vitro indicates the oncogenic roles of miR-1288 in ESCCs. Overexpression of miR-1288 play a key role in the pathogenesis of ESCCs and its modulation may have potential therapeutic value in patients with ESCC. Copyright © 2016 Elsevier Inc. All rights reserved.

Huntingtin-interacting protein 1 is overexpressed in prostate and colon cancer and is critical for cellular survival.

PubMed

Rao, Dinesh S; Hyun, Teresa S; Kumar, Priti D; Mizukami, Ikuko F; Rubin, Mark A; Lucas, Peter C; Sanda, Martin G; Ross, Theodora S

2002-08-01

Huntingtin-interacting protein 1 (HIP1) is a cofactor in clathrin-mediated vesicle trafficking. It was first implicated in cancer biology as part of a chromosomal translocation in leukemia. Here we report that HIP1 is expressed in prostate and colon tumor cells, but not in corresponding benign epithelia. The relationship between HIP1 expression in primary prostate cancer and clinical outcomes was evaluated with tissue microarrays. HIP1 expression was significantly associated with prostate cancer progression and metastasis. Conversely, primary prostate cancers lacking HIP1 expression consistently showed no progression after radical prostatectomy. In addition, the expression of HIP1 was elevated in prostate tumors from the transgenic mouse model of prostate cancer (TRAMP). At the molecular level, expression of a dominant negative mutant of HIP1 led to caspase-9-dependent apoptosis, suggesting that HIP1 is a cellular survival factor. Thus, HIP1 may play a role in tumorigenesis by allowing the survival of precancerous or cancerous cells. HIP1 might accomplish this via regulation of clathrin-mediated trafficking, a fundamental cellular pathway that has not previously been associated with tumorigenesis. HIP1 represents a putative prognostic factor for prostate cancer and a potential therapy target in prostate as well as colon cancers.

Huntingtin-interacting protein 1 is overexpressed in prostate and colon cancer and is critical for cellular survival

PubMed Central

Rao, Dinesh S.; Hyun, Teresa S.; Kumar, Priti D.; Mizukami, Ikuko F.; Rubin, Mark A.; Lucas, Peter C.; Sanda, Martin G.; Ross, Theodora S.

2002-01-01

Huntingtin-interacting protein 1 (HIP1) is a cofactor in clathrin-mediated vesicle trafficking. It was first implicated in cancer biology as part of a chromosomal translocation in leukemia. Here we report that HIP1 is expressed in prostate and colon tumor cells, but not in corresponding benign epithelia. The relationship between HIP1 expression in primary prostate cancer and clinical outcomes was evaluated with tissue microarrays. HIP1 expression was significantly associated with prostate cancer progression and metastasis. Conversely, primary prostate cancers lacking HIP1 expression consistently showed no progression after radical prostatectomy. In addition, the expression of HIP1 was elevated in prostate tumors from the transgenic mouse model of prostate cancer (TRAMP). At the molecular level, expression of a dominant negative mutant of HIP1 led to caspase-9–dependent apoptosis, suggesting that HIP1 is a cellular survival factor. Thus, HIP1 may play a role in tumorigenesis by allowing the survival of precancerous or cancerous cells. HIP1 might accomplish this via regulation of clathrin-mediated trafficking, a fundamental cellular pathway that has not previously been associated with tumorigenesis. HIP1 represents a putative prognostic factor for prostate cancer and a potential therapy target in prostate as well as colon cancers. PMID:12163454

Gene expression in mdx mouse muscle in relation to age and exercise: aberrant mechanical-metabolic coupling and implications for pre-clinical studies in Duchenne muscular dystrophy.

PubMed

Camerino, Giulia Maria; Cannone, Maria; Giustino, Arcangela; Massari, Ada Maria; Capogrosso, Roberta Francesca; Cozzoli, Anna; De Luca, Annamaria

2014-11-01

Weakness and fatigability are typical features of Duchenne muscular dystrophy patients and are aggravated in dystrophic mdx mice by chronic treadmill exercise. Mechanical activity modulates gene expression and muscle plasticity. Here, we investigated the outcome of 4 (T4, 8 weeks of age) and 12 (T12, 16 weeks of age) weeks of either exercise or cage-based activity on a large set of genes in the gastrocnemius muscle of mdx and wild-type (WT) mice using quantitative real-time PCR. Basal expression of the exercise-sensitive genes peroxisome-proliferator receptor γ coactivator 1α (Pgc-1α) and Sirtuin1 (Sirt1) was higher in mdx versus WT mice at both ages. Exercise increased Pgc-1α expression in WT mice; Pgc-1α was downregulated by T12 exercise in mdx muscles, along with Sirt1, Pparγ and the autophagy marker Bnip3. Sixteen weeks old mdx mice showed a basal overexpression of the slow Mhc1 isoform and Serca2; T12 exercise fully contrasted this basal adaptation as well as the high expression of follistatin and myogenin. Conversely, T12 exercise was ineffective in WT mice. Damage-related genes such as gp91-phox (NADPH-oxidase2), Tgfβ, Tnfα and c-Src tyrosine kinase were overexpressed in mdx muscles and not affected by exercise. Likewise, the anti-inflammatory adiponectin was lower in T12-exercised mdx muscles. Chronic exercise with minor adaptive effects in WT muscles leads to maladaptation in mdx muscles with a disequilibrium between protective and damaging signals. Increased understanding of the pathways involved in the altered mechanical-metabolic coupling may help guide appropriate physical therapies while better addressing pharmacological interventions in translational research. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Magnaporthe oryzae Induces the Expression of a MicroRNA to Suppress the Immune Response in Rice.

PubMed

Zhang, Xin; Bao, Yalin; Shan, Deqi; Wang, Zhihui; Song, Xiaoning; Wang, Zhaoyun; Wang, Jiansheng; He, Liqiang; Wu, Liang; Zhang, Zhengguang; Niu, Dongdong; Jin, Hailing; Zhao, Hongwei

2018-05-01

MicroRNAs play crucial roles in plant responses to pathogen infections. The rice blast disease, caused by the fungus Magnaporthe oryzae , is the most important disease of rice ( Oryza sativa ). To explore the microRNA species that participate in rice immunity against the rice blast disease, we compared the expression of small RNAs between mock- and M. oryzae -treated rice. We found that infection by M. oryzae strain Guy11 specifically induced the expression of rice miR319 and, consequently, suppressed its target gene TEOSINTE BRANCHED/CYCLOIDEA/PROLIFERATING CELL FACTOR1 ( OsTCP21 ), which encodes a transcription factor. Using transgenic rice that overexpresses miR319b (OE) or expresses OsTCP21 -Res (which is resistant to miR319-mediated silencing), we found that OsTCP21 is a positive regulator of the rice defense response against the blast disease. When wild-type and miR319b-OE rice were infected by Guy11, multiple jasmonic acid (JA) synthetic and signaling components were suppressed, indicating that Guy11 suppresses JA signaling through inducing miR319. In particular, we found that LIPOXYGENASE2 ( LOX2 ) and LOX5 were specifically suppressed by miR319 overexpression or by Guy11 infection. LOXs are the key enzymes of JA synthesis, which catalyze the conversion of α-linoleic acid to hydroperoxy-octadecadienoic acid. The application of α-linoleic acid rescued disease symptoms on the OsTCP21 -Res rice but not wild-type rice, supporting our hypothesis that OsLOX2 and OsLOX5 are the key JA synthesis genes hijacked by Guy11 to subvert host immunity and facilitate pathogenicity. We propose that induced expression of OsLOX2/5 may improve resistance to the rice blast disease. © 2018 American Society of Plant Biologists. All Rights Reserved.

Magnaporthe oryzae Induces the Expression of a MicroRNA to Suppress the Immune Response in Rice1[OPEN

PubMed Central

Zhang, Xin; Bao, Yalin; Shan, Deqi; Wang, Zhihui; Song, Xiaoning; Wang, Zhaoyun; Wang, Jiansheng; He, Liqiang; Wu, Liang; Zhang, Zhengguang; Niu, Dongdong

2018-01-01

MicroRNAs play crucial roles in plant responses to pathogen infections. The rice blast disease, caused by the fungus Magnaporthe oryzae, is the most important disease of rice (Oryza sativa). To explore the microRNA species that participate in rice immunity against the rice blast disease, we compared the expression of small RNAs between mock- and M. oryzae-treated rice. We found that infection by M. oryzae strain Guy11 specifically induced the expression of rice miR319 and, consequently, suppressed its target gene TEOSINTE BRANCHED/CYCLOIDEA/PROLIFERATING CELL FACTOR1 (OsTCP21), which encodes a transcription factor. Using transgenic rice that overexpresses miR319b (OE) or expresses OsTCP21-Res (which is resistant to miR319-mediated silencing), we found that OsTCP21 is a positive regulator of the rice defense response against the blast disease. When wild-type and miR319b-OE rice were infected by Guy11, multiple jasmonic acid (JA) synthetic and signaling components were suppressed, indicating that Guy11 suppresses JA signaling through inducing miR319. In particular, we found that LIPOXYGENASE2 (LOX2) and LOX5 were specifically suppressed by miR319 overexpression or by Guy11 infection. LOXs are the key enzymes of JA synthesis, which catalyze the conversion of α-linoleic acid to hydroperoxy-octadecadienoic acid. The application of α-linoleic acid rescued disease symptoms on the OsTCP21-Res rice but not wild-type rice, supporting our hypothesis that OsLOX2 and OsLOX5 are the key JA synthesis genes hijacked by Guy11 to subvert host immunity and facilitate pathogenicity. We propose that induced expression of OsLOX2/5 may improve resistance to the rice blast disease. PMID:29549093

The use of a viral 2A sequence for the simultaneous over-expression of both the vgf gene and enhanced green fluorescent protein (eGFP) in vitro and in vivo

PubMed Central

Lewis, Jo E.; Brameld, John M.; Hill, Phil; Barrett, Perry; Ebling, Francis J.P.; Jethwa, Preeti H.

2015-01-01

Introduction The viral 2A sequence has become an attractive alternative to the traditional internal ribosomal entry site (IRES) for simultaneous over-expression of two genes and in combination with recombinant adeno-associated viruses (rAAV) has been used to manipulate gene expression in vitro. New method To develop a rAAV construct in combination with the viral 2A sequence to allow long-term over-expression of the vgf gene and fluorescent marker gene for tracking of the transfected neurones in vivo. Results Transient transfection of the AAV plasmid containing the vgf gene, viral 2A sequence and eGFP into SH-SY5Y cells resulted in eGFP fluorescence comparable to a commercially available reporter construct. This increase in fluorescent cells was accompanied by an increase in VGF mRNA expression. Infusion of the rAAV vector containing the vgf gene, viral 2A sequence and eGFP resulted in eGFP fluorescence in the hypothalamus of both mice and Siberian hamsters, 32 weeks post infusion. In situ hybridisation confirmed that the location of VGF mRNA expression in the hypothalamus corresponded to the eGFP pattern of fluorescence. Comparison with old method The viral 2A sequence is much smaller than the traditional IRES and therefore allowed over-expression of the vgf gene with fluorescent tracking without compromising viral capacity. Conclusion The use of the viral 2A sequence in the AAV plasmid allowed the simultaneous expression of both genes in vitro. When used in combination with rAAV it resulted in long-term over-expression of both genes at equivalent locations in the hypothalamus of both Siberian hamsters and mice, without any adverse effects. PMID:26300182

PGC-1 Coactivators Regulate MITF and the Tanning Response

PubMed Central

Shoag, Jonathan; Haq, Rizwan; Zhang, Mingfeng; Liu, Laura; Rowe, Glenn C.; Jiang, Aihua; Koulisis, Nicole; Farrel, Caitlin; Amos, Christopher I.; Wei, Qingyi; Lee, Jeffrey E.; Zhang, Jiangwen; Kupper, Thomas S.; Qureshi, Abrar A.; Cui, Rutao; Han, Jiali; Fisher, David E.; Arany, Zoltan

2013-01-01

SUMMARY The production of pigment by melanocytes tans the skin and protects against skin cancers. UV-exposed keratinocytes secrete α-MSH, which then activates melanin formation in melanocytes by inducing the microphthalmia-associated transcription factor (MITF). We show that PPAR-γ coactivator (PGC)-1α and PGC-1β are critical components of this melanogenic system in melanocytes. α-MSH signaling strongly induces PGC-1α expression and stabilizes both PGC-1α and PGC-1β proteins. The PGC-1s in turn activate the MITF promoter, and their expression correlates strongly with that of MITF in human melanoma cell lines and biopsy specimens. Inhibition of PGC-1α and PGC-1β blocks the α-MSH-mediated induction of MITF and melanogenic genes. Conversely, overexpression of PGC-1α induces pigment formation in cell culture and transgenic animals. Finally, polymorphism studies reveal expression quantitative trait loci in the PGC-1β gene that correlate with tanning ability and protection from melanoma in humans. These data identify PGC-1 coactivators as regulators of human tanning. PMID:23201126

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

Yoon, Sarah; Jung, Jaesung; Kim, Taeyeung

In this study, HepG2-hepatitis B virus (HBV)-stable cells that did not overexpress HBx and HBx-deficient mutant-transfected cells were analyzed for their expression of HBV-induced, upregulated adipogenic and lipogenic genes. The mRNAs of CCAAT enhancer binding protein {alpha} (C/EBP{alpha}), peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}), adiponectin, liver X receptor {alpha} (LXR{alpha}), sterol regulatory element binding protein 1c (SREBP1c), and fatty acid synthase (FAS) were expressed at higher levels in HepG2-HBV and lamivudine-treated stable cells and HBx-deficient mutant-transfected cells than in the HepG2 cells. Lamivudine treatment reduced the mRNA levels of PPAR{gamma} and C/EBP{alpha}. Conversely, HBV replication was upregulated by adiponectin and PPAR{gamma}more » agonist rosiglitazone treatments and was downregulated by adiponectin siRNAs. Collectively, our results demonstrate that HBV replication and/or protein expression, even in the absence of HBx, upregulated adipogenic or lipogenic genes, and that the control of adiponectin might prove useful as a therapeutic modality for the treatment of chronic hepatitis B.« less

Monoacylglycerol lipase promotes metastases in nasopharyngeal carcinoma.

PubMed

Hu, Wen-Rong; Lian, Yi-Fan; Peng, Li-Xia; Lei, Jin-Ju; Deng, Cheng-Cheng; Xu, Miao; Feng, Qi-Sheng; Chen, Li-Zhen; Bei, Jin-Xin; Zeng, Yi-Xin

2014-01-01

Monoacylglycerol lipase (MAGL) is a serine hydrolase that hydrolyzes monoacylglycerides into free fatty acids and glycerol. It has recently been found to be involved in cancer progression through the free fatty acid or endocannabinoid network after studies on its function in the endocannabinoid system. Here, we determined a role for MAGL in nasopharyngeal carcinoma (NPC), which is known for its high metastatic potential. Among the different NPC cells we tested, MAGL was highly expressed in high metastatic NPC cells, whereas low metastatic potential NPC cells exhibited lower expression of MAGL. Overexpression of MAGL in low metastatic NPC cells enhanced their motile behavior and metastatic capacity in vivo. Conversely, knockdown of MAGL reduced the motility of highly metastatic cells, reducing their metastatic capacity in vivo. Growth rate was not influenced by MAGL in either high or low metastatic cells. MAGL expression was associated with the epithelial-mesenchymal transition (EMT) proteins, such as E-cadherin, vimentin and Snail. It was also related to the sidepopulation (SP) of NPC cells. Our findings establish that MAGL promotes metastases in NPC through EMT, and it may serve as a target for the prevention of NPC metastases.

Fgf9 from dermal γδ T cells induces hair follicle neogenesis after wounding

PubMed Central

Gay, Denise; Kwon, Ohsang; Zhang, Zhikun; Spata, Michelle; Plikus, Maksim V; Holler, Phillip D; Ito, Mayumi; Yang, Zaixin; Treffeisen, Elsa; Kim, Chang D; Nace, Arben; Zhang, Xiaohong; Baratono, Sheena; Wang, Fen; Ornitz, David M; Millar, Sarah E; Cotsarelis, George

2014-01-01

Understanding molecular mechanisms for regeneration of hair follicles provides new opportunities for developing treatments for hair loss and other skin disorders. Here we show that fibroblast growth factor 9 (Fgf9), initially secreted by γδ T cells, modulates hair follicle regeneration after wounding the skin of adult mice. Reducing Fgf9 expression decreases this wound-induced hair neogenesis (WIHN). Conversely, overexpression of Fgf9 results in a two- to threefold increase in the number of neogenic hair follicles. We found that Fgf9 from γδ T cells triggers Wnt expression and subsequent Wnt activation in wound fibroblasts. Through a unique feedback mechanism, activated fibroblasts then express Fgf9, thus amplifying Wnt activity throughout the wound dermis during a crucial phase of skin regeneration. Notably, humans lack a robust population of resident dermal γδ T cells, potentially explaining their inability to regenerate hair after wounding. These findings highlight the essential relationship between the immune system and tissue regeneration. The importance of Fgf9 in hair follicle regeneration suggests that it could be used therapeutically in humans. PMID:23727932

COX-2 Elevates Oncogenic miR-526b in Breast Cancer by EP4 Activation.

PubMed

Majumder, Mousumi; Landman, Erin; Liu, Ling; Hess, David; Lala, Peeyush K

2015-06-01

MicroRNAs (miRs) are small regulatory molecules emerging as potential biomarkers in cancer. Previously, it was shown that COX-2 expression promotes breast cancer progression via multiple mechanisms, including induction of stem-like cells (SLC), owing to activation of the prostaglandin E2 receptor EP4 (PTGER4). COX-2 overexpression also upregulated microRNA-526b (miR-526b), in association with aggressive phenotype. Here, the functional roles of miR-526b in breast cancer and the mechanistic role of EP4 signaling in miR-526b upregulation were examined. A positive correlation was noted between miR-526b and COX-2 mRNA expression in COX-2 disparate breast cancer cell lines. Stable overexpression of miR-526b in poorly metastatic MCF7 and SKBR3 cell lines resulted in increased cellular migration, invasion, EMT phenotype and enhanced tumorsphere formation in vitro, and lung colony formation in vivo in immunodeficient mice. Conversely, knockdown of miR-526b in aggressive MCF7-COX-2 and SKBR3-COX-2 cells reduced oncogenic functions and reversed the EMT phenotype, in vitro. Furthermore, it was determined that miR-526b expression is dependent on EP4 receptor activity and downstream PI3K-AKT and cyclic AMP (cAMP) signaling pathways. PI3K-AKT inhibitors blocked EP4 agonist-mediated miR-526b upregulation and tumorsphere formation in MCF7 and SKBR3 cells. NF-κB inhibitor abrogates EP agonist-stimulated miRNA expression in MCF7 and T47D cells, indicating that the NF-κB pathway is also involved in miR-526b regulation. In addition, inhibition of COX-2, EP4, PI3K, and PKA in COX-2-overexpressing cells downregulated miR-526b and its functions in vitro. Finally, miR-526b expression was significantly higher in cancerous than in noncancerous breast tissues and associated with reduced patient survival. In conclusion, miR-526b promotes breast cancer progression, SLC-phenotype through EP4-mediated signaling, and correlates with breast cancer patient survival. This study presents novel findings that miRNA 526b is a COX-2 upregulated, oncogenic miRNA promoting SLCs, the expression of which follows EP4 receptor-mediated signaling, and is a promising biomarker for monitoring and personalizing breast cancer therapy. ©2015 American Association for Cancer Research.

TC-1 Overexpression Promotes Cell Proliferation in Human Non-Small Cell Lung Cancer that Can Be Inhibited by PD173074

PubMed Central

Zhang, Na; Bai, Guangzhen; Zhong, Daixing; Su, Kai; Liu, Boya; Li, Xiaofei; Wang, Yunjie; Wang, Xiaoping

2014-01-01

Thyroid cancer-1 (TC-1), a natively disordered protein, is widely expressed in vertebrates and overexpressed in many kinds of tumors. However, its exact role and regulation mechanism in human non-small cell lung cancer (NSCLC) are still unclear. In the present study, we found that TC-1 is highly expressed in NSCLC and that its aberrant expression is strongly associated with NSCLC cell proliferation. Exogenous TC-1 overexpression promotes cell proliferation, accelerates the cell G1-to-S-phase transition, and reduces apoptosis in NSCLC. The knockdown of TC-1, however, inhibits NSCLC cell proliferation, cycle transition, and apoptosis resistance. Furthermore, we also demonstrated that PD173074, which functions as an inhibitor of the TC-1 in NSCLC, decreases the expression of TC-1 and inhibits TC-1 overexpression mediated cell proliferation in vitro and in vivo. Nevertheless, the inhibition function of PD173074 on NSCLC cell proliferation was eliminated in cells with TC-1 knockdown. These results suggest that PD173074 plays a significant role in TC-1 overexpression mediated NSCLC cell proliferation and may be a potential intervention target for the prevention of cell proliferation in NSCLC. PMID:24941347

Overexpression of GRß in colonic mucosal cell line partly reflects altered gene expression in colonic mucosa of patients with inflammatory bowel disease.

PubMed

Nagy, Zsolt; Acs, Bence; Butz, Henriett; Feldman, Karolina; Marta, Alexa; Szabo, Peter M; Baghy, Kornelia; Pazmany, Tamas; Racz, Karoly; Liko, Istvan; Patocs, Attila

2016-01-01

The glucocorticoid receptor (GR) plays a crucial role in inflammatory responses. GR has several isoforms, of which the most deeply studied are the GRα and GRß. Recently it has been suggested that in addition to its negative dominant effect on GRα, the GRß may have a GRα-independent transcriptional activity. The GRß isoform was found to be frequently overexpressed in various autoimmune diseases, including inflammatory bowel disease (IBD). In this study, we wished to test whether the gene expression profile found in a GRß overexpressing intestinal cell line (Caco-2GRß) might mimic the gene expression alterations found in patients with IBD. Whole genome microarray analysis was performed in both normal and GRß overexpressing Caco-2 cell lines with and without dexamethasone treatment. IBD-related genes were identified from a meta-analysis of 245 microarrays available in online microarray deposits performed on intestinal mucosa samples from patients with IBD and healthy individuals. The differentially expressed genes were further studied using in silico pathway analysis. Overexpression of GRß altered a large proportion of genes that were not regulated by dexamethasone suggesting that GRß may have a GRα-independent role in the regulation of gene expression. About 10% of genes differentially expressed in colonic mucosa samples from IBD patients compared to normal subjects were also detected in Caco-2 GRß intestinal cell line. Common genes are involved in cell adhesion and cell proliferation. Overexpression of GRß in intestinal cells may affect appropriate mucosal repair and intact barrier function. The proposed novel role of GRß in intestinal epithelium warrants further studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Enhancement of Chlorogenic Acid Production in Hairy Roots of Platycodon grandiflorum by Over-Expression of An Arabidopsis thaliana Transcription Factor AtPAP1

PubMed Central

Tuan, Pham Anh; Kwon, Do Yeon; Lee, Sanghyun; Arasu, Mariadhas Valan; Al-Dhabi, Naif Abdullah; Park, Nam Il; Park, Sang Un

2014-01-01

To improve the production of chlorogenic acid (CGA) in hairy roots of Platycodon grandiflorum, we induced over-expression of Arabidopsis thaliana transcription factor production of anthocyanin pigment (AtPAP1) using an Agrobacterium rhizogenes-mediated transformation system. Twelve hairy root lines showing over-expression of AtPAP1 were generated. In order to investigate the regulation of AtPAP1 on the activities of CGA biosynthetic genes, the expression levels of seven P. grandiflorum CGA biosynthetic genes were analyzed in the hairy root line that had the greatest accumulation of AtPAP1 transcript, OxPAP1-1. The introduction of AtPAP1 increased the mRNA levels of all examined CGA biosynthetic genes and resulted in a 900% up-regulation of CGA accumulation in OxPAP1-1 hairy roots relative to controls. This suggests that P. grandiflorum hairy roots that over-express the AtPAP1 gene are a potential alternative source of roots for the production of CGA. PMID:25153629

Distinct Protein Expression Profiles of Solid-Pseudopapillary Neoplasms of the Pancreas.

PubMed

Park, Minhee; Lim, Jong-Sun; Lee, Hyoung-Joo; Na, Keun; Lee, Min Jung; Kang, Chang Moo; Paik, Young-Ki; Kim, Hoguen

2015-08-07

Solid-pseudopapillary neoplasm (SPN) is an uncommon pancreatic tumor with mutation in CTNNB1 and distinct clinical and pathological features. We compared the proteomic profiles of SPN to mRNA expression. Pooled SPNs and pooled non-neoplastic pancreatic tissues were examined with high-resolution mass spectrometry. We identified 329 (150 up-regulated and 179 down-regulated) differentially expressed proteins in SPN. We identified 191 proteins (58.1% of the 329 dysregulated proteins) with the same expression tendencies in SPN based on mRNA data. Many overexpressed proteins were related to signaling pathways known to be activated in SPNs. We found that several proteins involved in Wnt signaling, including DKK4 and β-catenin, and proteins that bind β-catenin, such as FUS and NONO, were up-regulated in SPNs. Molecules involved in glycolysis, including PKM2, ENO2, and HK1, were overexpressed in accordance to their mRNA levels. In summary, SPN showed (1) distinct protein expression changes that correlated with mRNA expression, (2) overexpression of Wnt signaling proteins and proteins that bind directly to β-catenin, and (3) overexpression of proteins involved in metabolism. These findings may help develop early diagnostic biomarkers and molecular targets.

Overexpression of p53 mRNA in colorectal cancer and its relationship to p53 gene mutation.

PubMed Central

el-Mahdani, N.; Vaillant, J. C.; Guiguet, M.; Prévot, S.; Bertrand, V.; Bernard, C.; Parc, R.; Béréziat, G.; Hermelin, B.

1997-01-01

We analysed the frequency of p53 mRNA overexpression in a series of 109 primary colorectal carcinomas and its association with p53 gene mutation, which has been correlated with short survival. Sixty-nine of the 109 cases (63%) demonstrated p53 mRNA overexpression, without any correlation with stage or site of disease. Comparison with p53 gene mutation indicated that, besides cases in which p53 gene mutation and p53 mRNA overexpression were either both present (40 cases) or both absent (36 cases), there were also cases in which p53 mRNA was overexpressed in the absence of any mutation (29 cases) and those with a mutant gene in which the mRNA was not overexpressed (four cases). Moreover, the mutant p53 tumours exhibited an increase of p53 mRNA expression, which was significantly higher in tumours expressing the mutated allele alone than in tumours expressing both wild- and mutated-type alleles. These data (1) show that p53 mRNA overexpression is a frequent event in colorectal tumours and is not predictive of the status of the gene, i.e. whether or not a mutation is present; (2) provide further evidence that p53 protein overexpression does not only result from an increase in the half-life of mutated p53 and suggest that inactivation of the p53 function in colorectal cancers involves at least two distinct mechanisms, including p53 overexpression and/or mutation; and (3) suggest that p53 mRNA overexpression is an early event, since it is not correlated with Dukes stage. PMID:9052405

Over-expression of mammaglobin-B in canine mammary tumors.

PubMed

Pandey, Mamta; Sunil Kumar, B V; Gupta, Kuldip; Sethi, Ram Saran; Kumar, Ashwani; Verma, Ramneek

2018-06-15

Mammaglobin, a member of secretoglobin family has been recognized as a breast cancer associated protein. Though the exact function of the protein is not fully known, its expression has been reported to be upregulated in human breast cancer.We focused on studying the expression of mammaglobin-B gene and protein in canine mammary tumor (CMT) tissue. Expression of mammaglobin-B mRNA and protein were assessed by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC), respectively. High levels of mammaglobin-B mRNA expression (6.663 ± 0.841times) was observed in CMT as compared to age and breed matched healthy controls. Further, expression of mammaglobin-B protein was detected in paraffin-embedded mammary tumor tissues from the same subjects by IHC. Mammaglobin-B protein was overexpressed only in 6.67% of healthy mammary glands while, a high level of its expression was scored in 76.7% of the CMT subjects. Moreover, no significant differences in terms of IHC score and qRT-PCR score with respect to CMT histotypes or tumor grades were observed, indicating that mammaglobin-B over-expression occurred irrespective of CMT types or grades. Overall, significantly increased expression of mammaglobin-B protein was found in CMTs with respect to healthy mammary glands, which positively correlates to its transcript. These findings suggest that overexpression of mammaglobin-B is associated with tumors of canine mammary glands.

Osteopontin-a splice variant is overexpressed in papillary thyroid carcinoma and modulates invasive behavior

PubMed Central

Ferreira, Luciana Bueno; Tavares, Catarina; Pestana, Ana; Pereira, Catarina Leite; Eloy, Catarina; Pinto, Marta Teixeira; Castro, Patricia; Batista, Rui; Rios, Elisabete; Sobrinho-Simões, Manuel; Pereira Gimba, Etel Rodrigues; Soares, Paula

2016-01-01

Osteopontin (OPN) is a matricellular protein overexpressed in cancer cells and modulates tumorigenesis and metastasis, including in thyroid cancer (TC). The contribution of each OPN splice variant (OPN-SV), named OPNa, OPNb and OPNc, in TC is currently unknown. This study evaluates the expression of total OPN (tOPN) and OPN-SV in TC tissues and cell lines, their correlation with clinicopathological, molecular features and their functional roles. We showed that tOPN and OPNa are overexpressed in classic papillary thyroid carcinoma (cPTC) in relation to adjacent thyroid, adenoma and follicular variant of papillary thyroid carcinoma (fvPTC) tissues. In cPTC, OPNa overexpression is associated with larger tumor size, vascular invasion, extrathyroid extension and BRAFV600E mutation. We found that TC cell lines overexpressing OPNa exhibited increased proliferation, migration, motility and in vivo invasion. Conditioned medium secreted from cells overexpressing OPNa induce MMP2 and MMP9 metalloproteinases activity. In summary, we described the expression pattern of OPN-SV in cPTC samples and the key role of OPNa expression on activating TC tumor progression features. Our findings highlight OPNa variant as TC biomarker, besides being a putative target for cPTC therapeutic approaches. PMID:27409830

Osteopontin-a splice variant is overexpressed in papillary thyroid carcinoma and modulates invasive behavior.

PubMed

Ferreira, Luciana Bueno; Tavares, Catarina; Pestana, Ana; Pereira, Catarina Leite; Eloy, Catarina; Pinto, Marta Teixeira; Castro, Patricia; Batista, Rui; Rios, Elisabete; Sobrinho-Simões, Manuel; Gimba, Etel Rodrigues Pereira; Soares, Paula

2016-08-09

Osteopontin (OPN) is a matricellular protein overexpressed in cancer cells and modulates tumorigenesis and metastasis, including in thyroid cancer (TC). The contribution of each OPN splice variant (OPN-SV), named OPNa, OPNb and OPNc, in TC is currently unknown. This study evaluates the expression of total OPN (tOPN) and OPN-SV in TC tissues and cell lines, their correlation with clinicopathological, molecular features and their functional roles. We showed that tOPN and OPNa are overexpressed in classic papillary thyroid carcinoma (cPTC) in relation to adjacent thyroid, adenoma and follicular variant of papillary thyroid carcinoma (fvPTC) tissues. In cPTC, OPNa overexpression is associated with larger tumor size, vascular invasion, extrathyroid extension and BRAFV600E mutation. We found that TC cell lines overexpressing OPNa exhibited increased proliferation, migration, motility and in vivo invasion. Conditioned medium secreted from cells overexpressing OPNa induce MMP2 and MMP9 metalloproteinases activity. In summary, we described the expression pattern of OPN-SV in cPTC samples and the key role of OPNa expression on activating TC tumor progression features. Our findings highlight OPNa variant as TC biomarker, besides being a putative target for cPTC therapeutic approaches.

Prognostic impact of MYC protein expression in central nervous system diffuse large B-cell lymphoma: comparison with MYC rearrangement and MYC mRNA expression.

PubMed

Son, Seung-Myoung; Ha, Sang-Yun; Yoo, Hae-Yong; Oh, Dongryul; Kim, Seok-Jin; Kim, Won-Seog; Ko, Young-Hyeh

2017-01-01

The prognostic role of MYC has been well documented in non-central nervous system diffuse large B-cell lymphoma; however, it remains controversial in central nervous system diffuse large B-cell lymphoma. To investigate the prognostic value of MYC, we analyzed the MYC protein expression by immunohistochemistry, mRNA expression by RNA in situ hybridization, and gene status by fluorescence in situ hybridization in 74 cases of central nervous system diffuse large B-cell lymphoma. Moreover, we examined the correlation between MYC translocation, mRNA expression, and protein expression. The mean percentage of MYC immunopositive cells was 49%. Using a 44% cutoff value, 49 (66%) cases showed MYC protein overexpression. The result of mRNA in situ hybridization using the RNA scope technology was obtained using the H-scoring system; the median value was 34.2. Using the cutoff value of 63.5, 16 (22%) cases showed MYC mRNA overexpression. MYC gene rearrangement was detected in five out of 68 (7%) cases. MYC translocation showed no statistically significant correlation with mRNA expression; however, all MYC translocation-positive cases showed MYC protein overexpression, with a higher mean percentage of MYC protein expression than that of translocation-negative cases (78 vs 48%, P=0.001). The level of MYC mRNA expression was moderately correlated with the level of MYC protein expression (P<0.001). The mean percentage of MYC protein expression in the high MYC mRNA group was higher than that in the low MYC mRNA group (70 vs 47%, P<0.001). A univariate analysis showed that age over 60 years, Eastern Cooperative Oncology Group (ECOG) performance status ≥2 and MYC protein overexpression were significantly associated with an increased risk of death. MYC translocation and MYC mRNA expression had no prognostic significance. On multivariate analysis, MYC protein overexpression and ECOG score retained prognostic significance.

The metastasis suppressor gene KISS-1 regulates osteosarcoma apoptosis and autophagy processes.

PubMed

Yin, Yiran; Tang, Lian; Shi, Lei

2017-03-01

The expression of the metastasis suppressor gene KISS-1 in osteosarcoma cells during apoptosis and autophagy was evaluated. MG-63 osteosarcoma cells were transfected with either KISS-1 overexpression or KISS-1 knockdown expression vector in vitro, and compared with cell lines transfected with empty vector. After 12, 24, 48 and 72 h of cell culture, the cell proliferation was examined. The MTT method was used to detect apoptosis by flow cytometry, and the mRNA levels of apoptosis and autophagy markers caspase-3, Bcl-2, Bax, LC3 and Beclin1 were assessed by RT-PCR. Our results showed that cells in the control and low expression group kept proliferating during the cell culture period of 72 h, while the cells in the overexpression group progressively decreased in number. Also, the proliferation rate of the low expression group was significantly higher than that of the control group. The relative mRNA expression levels of caspase-3 and Bax mRNA in the control and low expression group showed no change (the expression was lowest in the low expression group). Moreover, the mRNA level of Bcl-2 increased in both cell groups. The mRNA expression levels of caspase-3 and Bax in the overexpression group were increased, and the level of Bcl-2 was reduced significantly. At the same time, the relative expression level of LC3 and Beclin1 mRNA in the control and low expression groups remained the same, and that of the overexpression group increased. The mRNA levels of LC3 and Beclin1 in the overexpression group were the highest, and that of the low expression group the lowest. The differences were statistically significant (P<0.05). Based on these results, we showed that KISS-1 inhibited the proliferation of osteosarcoma in vitro, probably by accelerating the processes of apoptosis and autophagy in the cells.

Nurr1 overexpression exerts neuroprotective and anti-inflammatory roles via down-regulating CCL2 expression in both in vivo and in vitro Parkinson's disease models

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

Liu, Wei; Gao, Yang; Chang, Na

The abnormality of nuclear receptor-related protein 1 (Nurr1) in expression and function can contribute to neurodegeneration of dopaminergic neurons and occurrence of Parkinson's disease (PD). However, its related mechanism in PD is still unknown. In this study, we found that Nurr1 was down-regulated and CCL2 was up-regulated in PD patients and PD mice. CCL2 promoted apoptosis and secretion of TNF-α and IL-1β in SH-SY5Y cells and inhibited cell viability while knockdown of CCL2 exerted the opposite effects. Nurr1 overexpression inhibited apoptosis, the release of TNF-α and IL-1β and promoted viability in α-Syn-treated SH-SY5Y cells, which was markedly promoted by CCL2more » antibody and dramatically reversed by CCL2. Nurr1 overexpression negatively regulated CCL2 expression in vivo and in vitro. Furthermore, Nurr1 overexpression remarkably relieved MPTP-induced movement disorder and spatial memory deficits and played neuroprotective and anti-inflammatory roles in MPTP-induced PD mice by down-regulating CCL2 in vivo. In conclusion, Nurr1 overexpression exerts neuroprotective and anti-inflammatory roles via down-regulating CCL2 in both in vivo and in vitro PD models, contributing to developing mechanism-based and neuroprotective strategies against PD. - Highlights: • Nurr1 was down-regulated and CCL2 was up-regulated in PD patients and PD mice. • Nurr1 overexpression inhibited apoptosis, release of TNF-α and IL-1β and promoted viability in α-Syn-treated SH-SY5Y cells. • CCL2 reversed the effect of Nurr1 overexpression on apoptosis, inflammatory cytokines secretion and viability. • Nurr1 overexpression negatively regulated CCL2 expression in vivo and in vitro. • Nurr1 overexpression remarkably relieved MPTP-induced movement disorder and spatial memory deficits.« less

FoxM1 Promotes Glioma Cells Progression by Up-Regulating Anxa1 Expression

PubMed Central

Cheng, Shi-Xiang; Tu, Yue; Zhang, Sai

2013-01-01

Forkhead box M1 (FoxM1) is a member of the forkhead transcription factor family and is overexpression in malignant gliomas. However, the molecular mechanisms by which FoxM1lead to glioma carcinogenesis and progression are still not well known. In the present study, we show that Anxa1 was overexpression in gliomas and predicted the poor outcome. Furthermore, Anxa1 closely related to the FoxM1 expression and was a direct transcriptional target of FoxM1. Overexpression of FoxM1 up-regulated Anxa1 expression, whereas suppression of FoxM1 expression down-regulated Anxa1 expression in glioma cells. Finally, FoxM1 enhanced the proliferation, migration, and angiogenesis in Anxa1-dependent manner both in vitro and in vivo. Our findings provide both clinical and mechanistic evidences that FoxM1 contributes to glioma development by directly up-regulating Anxa1 expression. PMID:23991102

Over-expression of Flt3 induces NF-kappaB pathway and increases the expression of IL-6.

PubMed

Takahashi, Shinichiro; Harigae, Hideo; Ishii, Keiko Kumura; Inomata, Mitsue; Fujiwara, Tohru; Yokoyama, Hisayuki; Ishizawa, Kenichi; Kameoka, Junichi; Licht, Jonathan D; Sasaki, Takeshi; Kaku, Mitsuo

2005-08-01

Activating mutations or over-expression of the Flt3 is prevalent in acute myeloblastic leukemia (AML), associated with activation of Ras/MAP kinase and other signaling pathways. In this study, we addressed the role of Flt3 in the activation of nuclear factor-kappa B (NF-kappaB), which is a target molecule of these kinase pathways. In BaF3 cells stably expressing Flt3, a NF-kappaB-responsive reporter was upregulated and its target gene, IL-6, was increased by the involvement of Flt3-ERK/MAPK-NF-kappaB pathway. Furthermore, we found a modest positive correlation (r=0.35, p=0.096) between Flt3 and IL-6 mRNA expression in 24 AML specimens. These results suggest a role of Flt3 over-expression in NF-kappaB pathway.

Transcriptional Regulation of Type 11 17β-Hydroxysteroid Dehydrogenase Expression in Prostate Cancer Cells

PubMed Central

Rotinen, Mirja; Villar, Joaquín; Celay, Jon; Serrano, Irantzu; Notario, Vicente; Encío, Ignacio

2011-01-01

Type 11 Hydroxysteroid (17-beta) dehydrogenase (HSD17B11) catalyzes the conversion of 5α-androstan-3α,17β-diol into androsterone suggesting that it may play an important role in androgen metabolism. We previously described that overexpression of C/EBPα or C/EBPβ induced HSD17B11 expression in HepG2 cells but this process was not mediated by the CCAAT boxes located within its proximal promoter region. Here, we study HSD17B11 transcriptional regulation in prostate cancer (PC) cells. Transfection experiments showed that the region −107/+18 is sufficient for promoter activity in PC cells. Mutagenesis analysis indicated that Sp1 and C/EBP binding sites found in this region are essential for promoter activity. Additional experiments demonstrated that ectopic expression of Sp1 and C/EBPα upregulated HSD17B11 expression only in PC cell lines. Through DAPA and ChIP assays, specific recruitment of Sp1 and C/EBPα to the HSD17B11 promoter was detected. These results show that HSD17B11 transcription in PC cells is regulated by Sp1 and C/EBPα. PMID:21549806

Overexpression of long intergenic noncoding RNA LINC00312 inhibits the invasion and migration of thyroid cancer cells by down-regulating microRNA-197-3p.

PubMed

Liu, Kai; Huang, Wen; Yan, Dan-Qing; Luo, Qing; Min, Xiang

2017-08-31

The study evaluated the ability of long intergenic noncoding RNA LINC00312 (LINC00312) to influence the proliferation, invasion, and migration of thyroid cancer (TC) cells by regulating miRNA-197-3p. TC tissues and adjacent normal tissues were collected from 211 TC patients. K1 (papillary TC), SW579 (squamous TC), and 8505C (anaplastic TC) cell lines were assigned into a blank, negative control (NC), LINC00312 overexpression, miR-197-3p inhibitors, and LINC00312 overexpression + miR-197-3p mimics group. The expression of LINC00312, miR-197-3p , and p120 were measured using quantitative real-time PCR (qRT-PCR) and Western blotting. Cell proliferation was assessed via CCK8 assay, cell invasion through the scratch test, and cell migration via Transwell assay. In comparison with adjacent normal tissues, the expression of LINC00312 is down-regulated and the expression of miR-197-3p is up-regulated in TC tissues. The dual luciferase reporter gene assay confirmed that P120 is a target of miR-197-3p The expression of LINC00312 and p120 was higher in the LINC00312 overexpression group than in the blank and NV groups. However, the expression of miR-197-3p was lower in the LINC00312 overexpression group than in the blank and NC groups. The miR-197-3p inhibitors group had a higher expression of miR-197-3p , but a lower expression of p120 than the blank and NC groups. The LINC00312 overexpression and miR-197-3p inhibitor groups had reduced cell proliferation, invasion and migration than the blank and NC groups. These results indicate that a LINC00312 overexpression inhibits the proliferation, invasion, and migration of TC cells and that this can be achieved by down-regulating miR-197-3p . © 2017 The Author(s).

Overexpression of Transcription Factor Sp1 Leads to Gene Expression Perturbations and Cell Cycle Inhibition

PubMed Central

Deniaud, Emmanuelle; Baguet, Joël; Chalard, Roxane; Blanquier, Bariza; Brinza, Lilia; Meunier, Julien; Michallet, Marie-Cécile; Laugraud, Aurélie; Ah-Soon, Claudette; Wierinckx, Anne; Castellazzi, Marc; Lachuer, Joël; Gautier, Christian

2009-01-01

Background The ubiquitous transcription factor Sp1 regulates the expression of a vast number of genes involved in many cellular functions ranging from differentiation to proliferation and apoptosis. Sp1 expression levels show a dramatic increase during transformation and this could play a critical role for tumour development or maintenance. Although Sp1 deregulation might be beneficial for tumour cells, its overexpression induces apoptosis of untransformed cells. Here we further characterised the functional and transcriptional responses of untransformed cells following Sp1 overexpression. Methodology and Principal Findings We made use of wild-type and DNA-binding-deficient Sp1 to demonstrate that the induction of apoptosis by Sp1 is dependent on its capacity to bind DNA. Genome-wide expression profiling identified genes involved in cancer, cell death and cell cycle as being enriched among differentially expressed genes following Sp1 overexpression. In silico search to determine the presence of Sp1 binding sites in the promoter region of modulated genes was conducted. Genes that contained Sp1 binding sites in their promoters were enriched among down-regulated genes. The endogenous sp1 gene is one of the most down-regulated suggesting a negative feedback loop induced by overexpressed Sp1. In contrast, genes containing Sp1 binding sites in their promoters were not enriched among up-regulated genes. These results suggest that the transcriptional response involves both direct Sp1-driven transcription and indirect mechanisms. Finally, we show that Sp1 overexpression led to a modified expression of G1/S transition regulatory genes such as the down-regulation of cyclin D2 and the up-regulation of cyclin G2 and cdkn2c/p18 expression. The biological significance of these modifications was confirmed by showing that the cells accumulated in the G1 phase of the cell cycle before the onset of apoptosis. Conclusion This study shows that the binding to DNA of overexpressed Sp1 induces an inhibition of cell cycle progression that precedes apoptosis and a transcriptional response targeting genes containing Sp1 binding sites in their promoter or not suggesting both direct Sp1-driven transcription and indirect mechanisms. PMID:19753117

Overexpressed long noncoding RNA CRNDE with distinct alternatively spliced isoforms in multiple cancers.

PubMed

Ma, Xuefei; Zhang, Wei; Zhang, Rong; Li, Jingming; Li, Shufen; Ma, Yunlin; Jin, Wen; Wang, Kankan

2018-05-26

Alternative splicing is a tightly regulated process that contributes to cancer development. CRNDE is a long noncoding RNA with alternative splicing and is implicated in the pathogenesis of several cancers. However, whether deregulated expression of CRNDE is common and which isoforms are mainly involved in cancers remain unclear. In this study, we report that CRNDE is aberrantly expressed in the majority of solid and hematopoietic malignancies. The investigation of CRNDE expression in normal samples revealed that CRNDE was expressed in a tissue- and cell-specific manner. Further comparison of CRNDE expression in 2938 patient samples from 15 solid and hematopoietic tumors showed that CRNDE was significantly overexpressed in 11 malignancies, including 3 reported and 8 unreported, and also implicated that the overexpressed isoforms differed in various cancer types. Furthermore, anti-cancer drugs could efficiently repress CRNDE overexpression in cancer cell lines and primary samples, and even had different impacts on the expression of CRNDE isoforms. Finally, experimental profiles of 12 alternatively spliced isoforms demonstrated that the spliced variant CRNDE-g was the most highly expressed isoform in multiple cancer types. Collectively, our results emphasize the cancer-associated feature of CRNDE and its spliced isoforms, and may provide promising targets for cancer diagnosis and therapy.

Prolyl isomerase Pin1 acts downstream of miR-200 to promote cancer stem-like cell traits in breast cancer

PubMed Central

Luo, Man-Li; Gong, Chang; Chen, Chun-Hau; Lee, Daniel Y.; Hu, Hai; Huang, Pengyu; Yao, Yandan; Guo, Wenjun; Reinhardt, Ferenc; Wulf, Gerburg; Lieberman, Judy; Zhou, Xiao Zhen; Song, Erwei; Lu, Kun Ping

2014-01-01

Breast cancer stem-like cells (BCSC) have been implicated in tumor growth, metastasis, drug resistance and relapse but druggable targets in appropriate subsets of this cell population have yet to be identified. Here we identify a fundamental role for the prolyl isomerase Pin1 in driving BCSC expansion, invasiveness and tumorigenicity, defining it as a key target of miR-200c which is known to be a critical regluator in BSCS. Pin1 overexpression expanded the growth and tumorigenicity of BCSC and triggered epithelial-mesenchymal transition (EMT). Conversely, genetic or pharmaacological inhibition of Pin1 reduced the abundance and self-renewal activity of BCSC. Moreover, moderate overexpression of miR-200c-resistant Pin1 rescued the BCSC defect in miR-200c-expressing cells. Genetic deletion of Pin1 also decreased the abundance and repopulating capability of normal mouse mammary stem cells. In human cells freshly isolated from reduction mammoplasty tissues, Pin1 overexpression endowed BCSC traits to normal breast epithelial cells, expanding both luminal and basal/myoepithelial lineages in these cells. In contrast, Pin1 silencing in primary breast cancer cells isolated from clinical samples inhibited the expansion, self-renewal activity and tumorigenesis of BCSC in vitro and in vivo. Overall, our work demonstrated that Pin1 is a pivotal regulator acting downstream of miR-200c to drive BCSC and breast tumorigenicity, highlighting a new therapeutic target to eradicate BCSC. PMID:24786790

A Txnrd1-dependent metabolic switch alters hepatic lipogenesis, glycogen storage, and detoxification

PubMed Central

Iverson, Sonya V.; Eriksson, Sofi; Xu, Jianqiang; Prigge, Justin R.; Talago, Emily A.; Meade, Tesia A.; Meade, Erin S.; Capecchi, Mario R.; Arnér, Elias S.J.; Schmidt, Edward E.

2013-01-01

Besides helping to maintain a reducing intracellular environment, the thioredoxin (Trx) system impacts bioenergetics and drug-metabolism. We show that hepatocyte-specific disruption of Txnrd1, encoding Trx reductase-1 (TrxR1), causes a metabolic switch in which lipogenic genes are repressed and periportal hepatocytes become engorged with glycogen. These livers also overexpress machinery for biosynthesis of glutathione and conversion of glycogen into UDP-glucuronate; they stockpile glutathione-S-transferases and UDP-glucuronyl-transferases; and they overexpress xenobiotic exporters. This realigned metabolic profile suggested that the mutant hepatocytes might be preconditioned to more effectively detoxify certain xenobiotic challenges. Hepatocytes convert the pro-toxin acetaminophen (APAP, paracetamol) into cytotoxic N-acetyl-p-benzoquinone imine (NAPQI). APAP defenses include glucuronidation of APAP or glutathionylation of NAPQI, allowing removal by xenobiotic exporters. We found that NAPQI directly inactivates TrxR1, yet Txnrd1-null livers were resistant to APAP-induced hepatotoxicity. Txnrd1-null livers did not have more effective gene expression responses to APAP challenge; however their constitutive metabolic state supported more robust GSH biosynthesis-, glutathionylation-, and glucuronidation-systems. Following APAP challenge, this effectively sustained the GSH system and attenuated damage. PMID:23743293

Genetic analysis of geraniol metabolism during fermentation.

PubMed

Steyer, Damien; Erny, Claude; Claudel, Patricia; Riveill, Geneviève; Karst, Francis; Legras, Jean-Luc

2013-04-01

Geraniol produced by grape is the main precursor of terpenols which play a key role in the floral aroma of white wines. We investigated the fate of geraniol during wine fermentation by Saccharomyces cerevisiae. The volatile compounds produced during fermentation of a medium enriched with geraniol were extracted by Stir-bar sorptive extraction and analysed by GC-MS. We were able to detect and quantify geranyl acetate but also citronellyl- and neryl-acetate. The presence of these compounds partly explains the disparition of geraniol. The amounts of terpenyl esters are strain dependant. We demonstrated both by gene overexpression and gene-deletion the involvement of ATF1 enzyme but not ATF2 in the acetylation of terpenols. The affinity of ATF1 enzyme for several terpenols and for isoamyl alcohol was compared. We also demonstrated that OYE2 is the enzyme involved in geraniol to citronellol reduction. Fermenting strain deleted from OYE2 gene produces far less citronellol than wild type strain. Moreover lab strain over-expressing OYE2 allows 87% geraniol to citronellol reduction in bioconversion experiment compared to about 50% conversion with control strain. Copyright © 2012 Elsevier Ltd. All rights reserved.

CHIP promotes thyroid cancer proliferation via activation of the MAPK and AKT pathways

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

Zhang, Li; Liu, Lianyong; Department of Endocrinology, Shanghai Punan Hospital, Shanghai 200125

The carboxyl terminus of Hsp70-interacting protein (CHIP) is a U box-type ubiquitin ligase that plays crucial roles in various biological processes, including tumor progression. To date, the functional mechanism of CHIP in thyroid cancer remains unknown. Here, we obtained evidence of upregulation of CHIP in thyroid cancer tissues and cell lines. CHIP overexpression markedly enhanced thyroid cancer cell viability and colony formation in vitro and accelerated tumor growth in vivo. Conversely, CHIP knockdown impaired cell proliferation and tumor growth. Notably, CHIP promoted cell growth through activation of MAPK and AKT pathways, subsequently decreasing p27 and increasing cyclin D1 and p-FOXO3a expression. Ourmore » findings collectively indicate that CHIP functions as an oncogene in thyroid cancer, and is therefore a potential therapeutic target for this disease. - Highlights: • CHIP is significantly upregulated in thyroid cancer cells. • Overexpression of CHIP facilitates proliferation and tumorigenesis of thyroid cancer cells. • Silencing of CHIP inhibits the proliferation and tumorigenesis of thyroid cancer cells. • CHIP promotes thyroid cancer cell proliferation via activating the MAPK and AKT pathways.« less

Nuclear orphan receptor TLX affects gene expression, proliferation and cell apoptosis in beta cells

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

Shi, Xiaoli; Xiong, Xiaokan; Dai, Zhe

2015-12-04

Nuclear orphan receptor TLX is an essential regulator of the growth of neural stem cells. However, its exact function in pancreatic islet cells is still unknown. In the present study, gene expression profiling analysis revealed that overexpression of TLX in beta cell line MIN6 causes suppression of 176 genes and upregulation of 49 genes, including a cadre of cell cycle, cell proliferation and cell death control genes, such as Btg2, Ddit3 and Gadd45a. We next examined the effects of TLX overexpression on proliferation, apoptosis and insulin secretion in MIN6 cells. Proliferation analysis using EdU assay showed that overexpression of TLXmore » increased percentage of EdU-positive cells. Cell cycle and apoptosis analysis revealed that overexpression of TLX in MIN6 cells resulted in higher percentage of cells exiting G1 into S-phase, and a 58.8% decrease of cell apoptosis induced by 0.5 mM palmitate. Moreover, TLX overexpression did not cause impairment of insulin secretion. Together, we conclude that TLX is among factors capable of controlling beta cell proliferation and survival, which may serve as a target for the development of novel therapies for diabetes. - Highlights: • TLX overexpression in MIN6 cell causes significant expression changes of 225 genes. • TLX overexpression promotes MIN6 cell proliferation and decreases cell apoptosis. • TLX overexpression does not cause impairment of insulin secretion.« less

c-erbB-2 in astrocytomas: infrequent overexpression by immunohistochemistry and absence of gene amplification by fluorescence in situ hybridization.

PubMed Central

Haapasalo, H.; Hyytinen, E.; Sallinen, P.; Helin, H.; Kallioniemi, O. P.; Isola, J.

1996-01-01

Recent studies suggest that aberrations of c-erbB-2 may be involved in astrocytic brain tumours. We screened immunohistochemically c-erbB2 protein (p185) expression in 94 astrocytic grade 1-4 neoplasms of the brain. The amplification of the c-erbB-2 oncogene was investigated in protein overexpression cases by dual colour fluorescence in situ hybridisation (FISH). p185 overexpression was correlated with p53 and epidermal growth factor receptor (EGFR) expression, as well as with clinicopathological features. Only two anaplastic (grade 3) astrocytomas and one glioblastoma (grade 4) showed overexpression of p185 protein by immunohistochemistry (monoclonal MAb1 antibody TA250), whereas none of the grade 1-2 astrocytomas was positive. Interestingly, the expression of p185 was confined solely to the cytoplasm of neoplastic astrocytic cells and not to the cell membranes as found in malignancies with amplification of the c-erbB-2 oncogene. Two of the three overexpression cases were also positive by EGFR. No amplification of the c-erbB-2 gene was observed by FISH in the three tumours with immunohistochemical p185 overexpression or seven weakly positive/negative tumours. In conclusion, our results suggest that p185 overexpression is infrequent in astrocytomas, that it is of no important diagnostic or prognostic value and that c-erbB-2 oncogene amplification is not seen in the few cases in which there is overexpression. Images Figure 1 Figure 2 PMID:8605096

Glypican-3 mRNA expression level in Wilms tumor: correlation with histological type, stage, and outcome.

PubMed

Wari, Md Nahidul; Vallonthaiel, Archana George; Ahmed, Aijaz; Saxena, Deepali; Iyer, Venkateswaran K; Mathur, Sandeep R; Agarwala, Sandeep; Bakhshi, Sameer; Srinivas, V; Chattopadhyaya, P; Sharma, Arundhati; Gupta, S Datta; Dinda, Amit

2017-06-01

To correlate expression of Glypican-3 in Wilms tumor with histopathology, stage, and outcome. Glypican-3 mRNA expression by real-time PCR on tumor and normal germline samples from 75 fresh nephrectomies for Wilms tumor with fold change after normalization against GAPDH was compared. Survival analysis for event-free and overall survival (EFS, OS) with 2-year follow-up for Glypican-3 overexpression (>1.5 times) and clinicopathological parameters was performed. Glypican-3 was overexpressed in 37/75 (49.3%). It was overexpressed in 77% (10/13) cases with blastema predominance or anaplastic histology, as compared to 44% of other histologies (27/62) (p = 0.03). OS was 73 and 93%, respectively (p = 0.016), for those with and without GPC-3 overexpression. EFS was not significantly different with Glypican-3 overexpression (p = 0.11). All 5 deaths among blastema predominant tumors and 4/5 deaths among triphasic tumors had overexpressed Glypican-3. Most deaths in Stage IV, Stage III, and Stage I + II (5/7, 3/3, 1/1) had GPC-3 overexpression. On multivariate analysis, only histology and stage were found to have independent prognostic value. Glypican-3 overexpression in Wilms tumor correlates with poor OS on univariate analysis. However, only histology and stage have independent prognostic value. Glypican-3 levels may help to stratify intermediate outcome histology (triphasic) and Stage III Wilms tumors.

Sarcospan Regulates Cardiac Isoproterenol Response and Prevents Duchenne Muscular Dystrophy-Associated Cardiomyopathy.

PubMed

Parvatiyar, Michelle S; Marshall, Jamie L; Nguyen, Reginald T; Jordan, Maria C; Richardson, Vanitra A; Roos, Kenneth P; Crosbie-Watson, Rachelle H

2015-12-23

Duchenne muscular dystrophy is a fatal cardiac and skeletal muscle disease resulting from mutations in the dystrophin gene. We have previously demonstrated that a dystrophin-associated protein, sarcospan (SSPN), ameliorated Duchenne muscular dystrophy skeletal muscle degeneration by activating compensatory pathways that regulate muscle cell adhesion (laminin-binding) to the extracellular matrix. Conversely, loss of SSPN destabilized skeletal muscle adhesion, hampered muscle regeneration, and reduced force properties. Given the importance of SSPN to skeletal muscle, we investigated the consequences of SSPN ablation in cardiac muscle and determined whether overexpression of SSPN into mdx mice ameliorates cardiac disease symptoms associated with Duchenne muscular dystrophy cardiomyopathy. SSPN-null mice exhibited cardiac enlargement, exacerbated cardiomyocyte hypertrophy, and increased fibrosis in response to β-adrenergic challenge (isoproterenol; 0.8 mg/day per 2 weeks). Biochemical analysis of SSPN-null cardiac muscle revealed reduced sarcolemma localization of many proteins with a known role in cardiomyopathy pathogenesis: dystrophin, the sarcoglycans (α-, δ-, and γ-subunits), and β1D integrin. Transgenic overexpression of SSPN in Duchenne muscular dystrophy mice (mdx(TG)) improved cardiomyofiber cell adhesion, sarcolemma integrity, cardiac functional parameters, as well as increased expression of compensatory transmembrane proteins that mediate attachment to the extracellular matrix. SSPN regulates sarcolemmal expression of laminin-binding complexes that are critical to cardiac muscle function and protects against transient and chronic injury, including inherited cardiomyopathy. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Pleiotrophin over-expression provides trophic support to dopaminergic neurons in parkinsonian rats

PubMed Central

2011-01-01

Background Pleiotrophin is known to promote the survival and differentiation of dopaminergic neurons in vitro and is up-regulated in the substantia nigra of Parkinson's disease patients. To establish whether pleiotrophin has a trophic effect on nigrostriatal dopaminergic neurons in vivo, we injected a recombinant adenovirus expressing pleiotrophin in the substantia nigra of 6-hydroxydopamine lesioned rats. Results The viral vector induced pleiotrophin over-expression by astrocytes in the substantia nigra pars compacta, without modifying endogenous neuronal expression. The percentage of tyrosine hydroxylase-immunoreactive cells as well as the area of their projections in the lesioned striatum was higher in pleiotrophin-treated animals than in controls. Conclusions These results indicate that pleiotrophin over-expression partially rescues tyrosine hydroxylase-immunoreactive cell bodies and terminals of dopaminergic neurons undergoing 6-hydroxydopamine-induced degeneration. PMID:21649894

Thromboxane synthase expression and correlation with VEGF and angiogenesis in non-small cell lung cancer.

PubMed

Cathcart, Mary Clare; Gately, Kathy; Cummins, Robert; Drakeford, Clive; Kay, Elaine W; O'Byrne, Kenneth J; Pidgeon, Graham P

2014-05-01

Thromboxane synthase (TXS) metabolizes prostaglandin H2 into thromboxanes, which are biologically active on cancer cells. TXS over-expression has been reported in a range of cancers, and associated with angiogenesis and poor outcome. TXS has been identified as a potential therapeutic target in NSCLC. This study examines a link between TXS expression, angiogenesis, and survival in NSCLC. TXS and VEGF metabolite levels were measured in NSCLC serum samples (n=46) by EIA. TXB2 levels were correlated with VEGF. A 204-patient TMA was stained for TXS, VEGF, and CD-31 expression. Expression was correlated with a range of clinical parameters, including overall survival. TXS expression was correlated with VEGF and CD-31. Stable TXS clones were generated and the effect of overexpression on tumor growth and angiogenesis markers was examined in-vitro and in-vivo (xenograft mouse model). Serum TXB2 levels were correlated with VEGF (p<0.05). TXS and VEGF were expressed to a varying degree in NSCLC tissue. TXS was associated with VEGF (p<0.0001) and microvessel density (CD-31; p<0.05). TXS and VEGF expression levels were higher in adenocarcinoma (p<0.0001) and female patients (p<0.05). Stable overexpression of TXS increased VEGF secretion in-vitro. While no significant association with patient survival was observed for either TXS or VEGF in our patient cohort, TXS overexpression significantly (p<0.05) increased tumor growth in-vivo. TXS overexpression was also associated with higher levels of VEGF, microvessel density, and reduced apoptosis in xenograft tumors. TXS promotes tumor growth in-vivo in NSCLC, an effect which is at least partly mediated through increased tumor angiogenesis. Copyright © 2014 Elsevier B.V. All rights reserved.

Functional characterisation of HvCO1, the barley (Hordeum vulgare) flowering time ortholog of CONSTANS.

PubMed

Campoli, Chiara; Drosse, Benedikt; Searle, Iain; Coupland, George; von Korff, Maria

2012-03-01

Variation in photoperiod response is a major factor determining plant development and the agronomic performance of crops. The genetic control of photoperiodic flowering has been elucidated in the model plant Arabidopsis, and many of the identified genes are structurally conserved in the grasses. In this study, HvCO1, the closest barley ortholog of the key photoperiod response gene CONSTANS in Arabidopsis, was over-expressed in the spring barley Golden Promise. Over-expression of HvCO1 accelerated time to flowering in long- and short-day conditions and caused up-regulation of HvFT1 mRNA under long-day conditions. However, the transgenic plants retained a response to photoperiod, suggesting the presence of photoperiod response factors acting downstream of HvCO1 transcription. Analysis of a population segregating for HvCO1 over-expression and natural genetic variation at Ppd-H1 demonstrated that Ppd-H1 acts downstream of HvCO1 transcription on HvFT1 expression and flowering. Furthermore, variation at Ppd-H1 did not affect diurnal expression of HvCO1 or HvCO2. Over-expression of HvCO1 increased transcription of the spring allele of Vrn-H1 in long- and short-day conditions, while genetic variation at Ppd-H1 did not affect Vrn-H1 expression. Over-expression of HvCO1 and natural genetic variation at Ppd-H1 accelerated inflorescence development and stem elongation. Thus, HvCO1 probably induces flowering by activating HvFT1 whilst Ppd-H1 regulates HvFT1 independently of HvCO1 mRNA, and all three genes also appear to have a strong effect in promoting inflorescence development. © 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd.

Overexpression of heterogeneous nuclear ribonucleoprotein F stimulates renal Ace-2 gene expression and prevents TGF-β1-induced kidney injury in a mouse model of diabetes.

PubMed

Lo, Chao-Sheng; Shi, Yixuan; Chang, Shiao-Ying; Abdo, Shaaban; Chenier, Isabelle; Filep, Janos G; Ingelfinger, Julie R; Zhang, Shao-Ling; Chan, John S D

2015-10-01

We investigated whether heterogeneous nuclear ribonucleoprotein F (hnRNP F) stimulates renal ACE-2 expression and prevents TGF-β1 signalling, TGF-β1 inhibition of Ace-2 gene expression and induction of tubulo-fibrosis in an Akita mouse model of type 1 diabetes. Adult male Akita transgenic (Tg) mice overexpressing specifically hnRNP F in their renal proximal tubular cells (RPTCs) were studied. Non-Akita littermates and Akita mice served as controls. Immortalised rat RPTCs stably transfected with plasmid containing either rat Hnrnpf cDNA or rat Ace-2 gene promoter were also studied. Overexpression of hnRNP F attenuated systemic hypertension, glomerular filtration rate, albumin/creatinine ratio, urinary angiotensinogen (AGT) and angiotensin (Ang) II levels, renal fibrosis and profibrotic gene (Agt, Tgf-β1, TGF-β receptor II [Tgf-βrII]) expression, stimulated anti-profibrotic gene (Ace-2 and Ang 1-7 receptor [MasR]) expression, and normalised urinary Ang 1-7 level in Akita Hnrnpf-Tg mice as compared with Akita mice. In vitro, hnRNP F overexpression stimulated Ace-2 gene promoter activity, mRNA and protein expression, and attenuated Agt, Tgf-β1 and Tgf-βrII gene expression. Furthermore, hnRNP F overexpression prevented TGF-β1 signalling and TGF-β1 inhibition of Ace-2 gene expression. These data demonstrate that hnRNP F stimulates Ace-2 gene transcription, prevents TGF-β1 inhibition of Ace-2 gene transcription and induction of kidney injury in diabetes. HnRNP F may be a potential target for treating hypertension and renal fibrosis in diabetes.

Overexpression of centrosomal protein Nlp confers breast carcinoma resistance to paclitaxel.

PubMed

Zhao, Weihong; Song, Yongmei; Xu, Binghe; Zhan, Qimin

2012-02-01

Nlp (ninein-like protein), an important molecule involved in centrosome maturation and spindle formation, plays an important role in tumorigenesis and its abnormal expression was recently observed in human breast and lung cancers. In this study, the correlation between overexpression of Nlp and paclitaxel chemosensitivity was investigated to explore the mechanisms of resistance to paclitaxel and to understand the effect of Nlp upon apoptosis induced by chemotherapeutic agents. Nlp expression vector was stably transfected into breast cancer MCF-7 cells. With Nlp overexpression, the survival rates, cell cycle distributions and apoptosis were analyzed in transfected MCF-7 cells by MTT test and FCM approach. The immunofluorescent assay was employed to detect the changes of microtubule after paclitaxel treatment. Immunoblotting analysis was used to examine expression of centrosomal proteins and apoptosis associated proteins. Subsequently, Nlp expression was retrospectively examined with 55 breast cancer samples derived from paclitaxel treated patients. Interestingly, the survival rates of MCF-7 cells with Nlp overexpressing were higher than that of control after paclitaxel treatment. Nlp overexpression promoted G2-M arrest and attenuated apoptosis induced by paclitaxel, which was coupled with elevated Bcl-2 protein. Nlp expression significantly lessened the microtubule polymerization and bundling elicited by paclitaxel attributing to alteration on the structure or dynamics of β-tubulin but not on its expression. The breast cancer patients with high expression of Nlp were likely resistant to the treatment of paclitaxel, as the response rate in Nlp negative patients was 62.5%, whereas was 58.3 and 15.8% in Nlp (+) and Nlp (++) patients respectively (p = 0.015). Nlp expression was positive correlated with those of Plk1 and PCNA. These findings provide insights into more rational chemotherapeutic regimens in clinical practice, and more effective approaches might be developed through targeting Nlp to increase chemotherapeutic sensitivity.

Botulinum toxin decreases hyperalgesia and inhibits P2X3 receptor over-expression in sensory neurons induced by ventral root transection in rats.

PubMed

Xiao, Lizu; Cheng, Jianguo; Dai, Juanli; Zhang, Deren

2011-09-01

We aim to determine the effects of Botulinum toxin type A (BTX-A) on neuropathic pain behavior and the expression of P2X(3) receptor in dorsal root ganglion (DRG) in rats with neuropathic pain induced by L5 ventral root transection (L5 VRT). Neuropathic pain was induced by L5 VRT in male Sprague-Dawley rats. Either saline or BTX-A was administered to the plantar surface. Behavioral tests were conducted preoperatively and at predefined postoperative days. The expression of P2X(3) receptors in DRG neurons was detected by immunoreactivity at postoperative days 3, 7, 14, and 21. The number of positive P2X(3) neurons in the ipsilateral L5 DRG increased significantly after L5 VRT (P<0.001). This increase persisted for at least 3 weeks after the operation. No significant changes in P2X(3) expression were detected in the contralateral L5, or in the L4 DRGs bilaterally. Subcutaneous administration of BTX-A, performed on the left hindpaw at days 4, 8, or 16 post VRT surgery, significantly reduced mechanical allodynia bilaterally and inhibited P2X(3) over-expression induced by L5 VRT. L5 VRT led to over-expression of P2X(3) receptors in the L5 DRG and bilateral mechanical allodynia in rats. Subcutaneous injection of BTX-A significantly reversed the neuropathic pain behavior and the over-expression of P2X(3) receptor in nociceptive neurons. These data not only show over-expression of purinergic receptors in the VRT model of neuropathic pain but also reveal a novel mechanism of botulinum toxin action on nociceptive neurons. Wiley Periodicals, Inc.

Reducing acetate excretion from E. coli K-12 by over-expressing the small RNA sgrS

PubMed Central

Negrete, Alejandro; Majdalani, Nadim; Phue, Je Nie; Shiloach, Joseph

2011-01-01

When exposed to the non-metabolized glucose derivative alpha methyl glucoside, both E. coli K-12 (JM109 and MG1655) and E. coli B (BL21) respond by reducing the concentration of the mRNA of the ptsG gene which is responsible for the biosynthesis of the glucose transporter EIICBglu. This occurs through the over-expression of the non-coding small RNA SgrS, which interacts specifically with the mRNA of the ptsG gene and prevents its translation. However, when these bacteria are exposed to a glucose concentration of 40 g/L, over-expression of SgrS is observed only in E. coli B (BL21). Unlike E. coli K-12 (JM109 and MG1655), which are affected by high glucose concentration and produce higher levels of acetate, E. coli B (BL21) is not affected. Based on this information, it was assumed that over-expression of SgrS enables E. coli B (BL21) to reduce its acetate excretion by controlling the glucose transport. When SgrS was over-expressed in both E. coli K-12 strains from a multicopy plasmid, it was possible to reduce their acetate excretion levels to those seen in E. coli B. This observation opens a new approach towards controlling bacterial metabolism through the use of non-coding RNA. PMID:22107968

Reducing acetate excretion from E. coli K-12 by over-expressing the small RNA SgrS.

PubMed

Negrete, Alejandro; Majdalani, Nadim; Phue, Je-Nie; Shiloach, Joseph

2013-01-25

When exposed to the nonmetabolized glucose derivative alpha methyl glucoside (αMG), both Escherichia coli K-12 (JM109 and MG1655) and E. coli B (BL21) respond by reducing the concentration of the mRNA of the ptsG gene which is responsible for the biosynthesis of the glucose transporter EIICB(glu). This occurs through the over-expression of the noncoding small RNA SgrS, which interacts specifically with the mRNA of the ptsG gene and prevents its translation. However, when these bacteria are exposed to a glucose concentration of 40 g/L, over-expression of SgrS is observed only in E. coli B (BL21). Unlike E. coli K-12 (JM109 and MG1655), which are affected by high glucose concentration and produce higher levels of acetate, E. coli B (BL21) is not affected. Based on this information, it was assumed that over-expression of SgrS enables E. coli B (BL21) to reduce its acetate excretion by controlling the glucose transport. When SgrS was over-expressed in both E. coli K-12 strains from a multicopy plasmid, it was possible to reduce their acetate excretion levels to those seen in E. coli B. This observation opens a new approach towards controlling bacterial metabolism through the use of noncoding RNA. Published by Elsevier B.V.

Over-expression of mammalian sialidase NEU3 reduces Newcastle disease virus entry and propagation in COS7 cells.

PubMed

Anastasia, Luigi; Holguera, Javier; Bianchi, Anna; D'Avila, Francesca; Papini, Nadia; Tringali, Cristina; Monti, Eugenio; Villar, Enrique; Venerando, Bruno; Muñoz-Barroso, Isabel; Tettamanti, Guido

2008-03-01

The paramyxovirus Newcastle Disease Virus (NDV) binds to sialic acid-containing glycoconjugates, sialoglycoproteins and sialoglycolipids (gangliosides) of host cell plasma membrane through its hemagglutinin-neuraminidase (sialidase) HN glycoprotein. We hypothesized that the modifications of the cell surface ganglioside pattern determined by over-expression of the mammalian plasma-membrane associated, ganglioside specific, sialidase NEU3 would affect the virus-host cell interactions. Using COS7 cells as a model system, we observed that over-expression of the murine MmNEU3 did not affect NDV binding but caused a marked reduction in NDV infection and virus propagation through cell-cell fusion. Moreover, since GD1a was greatly reduced in COS7 cells following NEU3-over-expression, we added [(3)H]-labelled GD1a to COS7 cells under conditions that block intralysosomal metabolic processing, and we observed a marked increase of GD1a cleavage to GM1 during NDV infection, indicating a direct involvement of the virus sialidase and host cell GD1a in NDV infectivity. Therefore, the decrease of GD1a in COS7 cell membrane upon MmNEU3 over-expression is likely to be instrumental to NDV reduced infection. Evidence was also provided for the preferential association of NDV-HN at 4 degrees C to detergent resistant microdomains (DRMs) of COS7 cells plasma membranes.

Over-expression of FoxM1 leads to epithelial-mesenchymal transition and cancer stem cell phenotype in pancreatic cancer cells

PubMed Central

Bao, Bin; Wang, Zhiwei; Ali, Shadan; Kong, Dejuan; Banerjee, Sanjeev; Ahmad, Aamir; Li, Yiwei; Azmi, Asfar S.; Miele, Lucio; Sarkar, Fazlul H.

2011-01-01

FoxM1 is known to play important role in the development and progression of many malignancies including pancreatic cancer. Studies have shown that the acquisition of Epithelial-to-mesenchymal transition (EMT) phenotype and induction of cancer stem cell (CSC) or cancer stem-like cell phenotypes are highly inter-related, and contributes to drug resistance, tumor recurrence and metastasis. The molecular mechanism(s) by which FoxM1 contributes to the acquisition of EMT phenotype and induction of CSC self-renewal capacity is poorly understood. Therefore, we established FoxM1 over-expressing pancreatic cancer (AsPC-1) cells, which showed increased cell growth, clonogenicity and cell migration. Moreover, over-expression of FoxM1 led to the acquisition of EMT phenotype by activation of mesenchymal cell markers, ZEB1, ZEB2, Snail2, E-cadherin, and vimentin, which is consistent with increased sphere-forming (pancreatospheres) capacity and expression of CSC surface markers (CD44 and EpCAM). We also found that over-expression of FoxM1 led to decreased expression of miRNAs (let-7a, let-7b, let-7c, miR-200b and miR-200c); however, re-expression of miR-200b inhibited the expression of ZEB1, ZEB2, vimentin as well as FoxM1, and induced the expression of E-cadherin, leading to the reversal of EMT phenotype. Finally, we found that genistein, a natural chemo-preventive agent, inhibited cell growth, clonogenicity, cell migration and invasion, EMT phenotype, and formation of pancreatospheres consistent with reduced expression of CD44 and EpCAM. These results suggest, for the first time, that FoxM1 over-expression is responsible for the acquisition of EMT and CSC phenotype, which is in part mediated through the regulation of miR-200b and these processes, could be easily attenuated by genistein. PMID:21503965

Overexpression of Populus×canescens isoprene synthase gene in Camelina sativa leads to alterations in its growth and metabolism.

PubMed

Rossi, Lorenzo; Borghi, Monica; Yang, Jinfen; Xie, De-Yu

2017-08-01

Isoprene (2-methyl-1,3-butadiene) is a hemiterpene molecule. It has been estimated that the plant kingdom emits 500-750 million tons of isoprene in the environment, half of which results from tropical broadleaf trees and the remainder from shrubs. Camelina (Camelina sativa (L.) Crantz) is an emerging bioenergy plant for biodiesel. In this study, we characterized isoprene formation following a diurnal/nocturnal cycle in wild-type Camelina plants. To understand the potential effects of isoprene emission on this herbaceous plant, a gray poplar Populus×canescens isoprene synthase gene (PcISPS) was overexpressed in Camelina. Transgenic plants showed increased isoprene production, and the emissions were characterized by a diurnal/nocturnal cycle. Measurements of the expression of six genes of the plastidial 2-C-methyl-d-erythriol-4-phosphate (MEP) pathway revealed that the expression patterns of three key genes were associated with isoprene formation dynamics in the three genotypic plants. Conversely, dissimilar gene expression levels existed in different genotypes, indicating that dynamics and variations occurred among plants. Moreover, transgenic plants grew shorter and developed smaller leaves than the wild-type and empty vector control transgenic plants. Photosynthetic analysis showed that the CO 2 assimilation rate, intracellular CO 2 concentration, mesophyll conductance and contents of chlorophylls a and b were similar among PcISPS transgenic, empty-vector control transgenic, and wild-type plants, indicating that the transgene did not negatively affect photosynthesis. Based on these results, we suggest that the reduced biomass was likely a trade-off consequence of the increased isoprene emission. Copyright © 2017 Elsevier GmbH. All rights reserved.

TIMP3 Overexpression Improves the Sensitivity of Osteosarcoma to Cisplatin by Reducing IL-6 Production

PubMed Central

Han, Xiu-guo; Mo, Hui-min; Liu, Xu-qiang; Li, Yan; Du, Lin; Qiao, Han; Fan, Qi-ming; Zhao, Jie; Zhang, Shu-hong; Tang, Ting-ting

2018-01-01

Osteosarcoma is the most common bone cancer in children and adolescents. Tissue inhibitors of metalloproteinases (TIMPs)-3 inhibit matrix metalloproteinases to limit extracellular matrix degradation. Cisplatin is a widely used chemotherapeutic drug used to cure osteosarcoma. Interleukin (IL)-6 and TIMP3 play important roles in the drug resistance of osteosarcoma; however, their relationship in this process remains unclear. This study aimed to explore the role of TIMP3 in the cisplatin sensitivity of osteosarcoma and its underlying molecular mechanisms in vitro and in vivo. We compared TIMP3 expression levels between patients with cisplatin-sensitive and -insensitive osteosarcoma. TIMP3 was overexpressed or knocked down in the Saos2-lung cell line, which is a Saos2 subtype isolated from pulmonary metastases that has higher cisplatin chemoresistance than Saos2 cells. IL-6 expression, cell proliferation, sensitivity to cisplatin, migration, and invasion after TIMP3 overexpression or knockdown were determined. The same experiments were performed using MG63 and U2OS cells. Subsequently, luciferase-labeled Saos2-lung cells overexpressing TIMP3 were injected into the tibiae of nude mice treated with cisplatin. The results showed that IL-6 inhibited TIMP3 expression in Saos2 and Saos2-lung cells via signal transducer and activator of transcription 3 (STAT3) activation. STAT3 knockdown reversed the effect of IL-6. The expression of TIMP3 was higher in patients with cisplatin-sensitive osteosarcoma than in those with insensitive osteosarcoma. IL-6 expression was downregulated upon TIMP3 overexpression, and upregulated by TIMP3 knockdown. TIMP3 overexpression suppressed cell proliferation and enhanced cisplatin sensitivity by activating apoptosis-related signal pathways and inhibiting IL-6 expression in vitro and in vivo. In conclusion, cisplatin sensitivity correlated positively with TIMP3 expression, which is regulated by the IL-6/TIMP3/caspase pathway. The TIMP3 pathway could represent a target for new therapies to treat osteosarcoma. PMID:29731768

FGF-mediated mesoderm induction involves the Src-family kinase Laloo.

PubMed

Weinstein, D C; Marden, J; Carnevali, F; Hemmati-Brivanlou, A

1998-08-27

During embryogenesis, inductive interactions underlie the development of much of the body plan. In Xenopus laevis, factors secreted from the vegetal pole induce mesoderm in the adjacent marginal zone; members of both the transforming growth factor-beta (TGF-beta) and fibroblast growth factor (FGF) ligand families seem to have critical roles in this process. Here we report the identification and characterization of laloo, a novel participant in the signal transduction cascade linking extracellular, mesoderm-inducing signals to the nucleus, where alteration of cell fate is driven by changes in gene expression. Overexpression of laloo, a member of the Src-related gene family, in Xenopus embryos gives rise to ectopic posterior structures that frequently contain axial tissue. Laloo induces mesoderm in Xenopus ectodermal explants; this induction is blocked by reagents that disrupt the FGF signalling pathway. Conversely, expression of a dominant-inhibitory Laloo mutant blocks mesoderm induction by FGF and causes severe posterior truncations in vivo. This work provides the first evidence that a Src-related kinase is involved in vertebrate mesoderm induction.

CBX7 gene expression plays a negative role in adipocyte cell growth and differentiation

PubMed Central

Forzati, Floriana; Federico, Antonella; Pallante, Pierlorenzo; Colamaio, Marianna; Esposito, Francesco; Sepe, Romina; Gargiulo, Sara; Luciano, Antonio; Arra, Claudio; Palma, Giuseppe; Bon, Giulia; Bucher, Stefania; Falcioni, Rita; Brunetti, Arturo; Battista, Sabrina; Fedele, Monica; Fusco, Alfredo

2014-01-01

ABSTRACT We have recently generated knockout mice for the Cbx7 gene, coding for a polycomb group protein that is downregulated in human malignant neoplasias. These mice develop liver and lung adenomas and carcinomas, which confirms a tumour suppressor role for CBX7. The CBX7 ability to downregulate CCNE1 expression likely accounts for the phenotype of the Cbx7-null mice. Unexpectedly, Cbx7-knockout mice had a higher fat tissue mass than wild-type, suggesting a role of CBX7 in adipogenesis. Consistently, we demonstrate that Cbx7-null mouse embryonic fibroblasts go towards adipocyte differentiation more efficiently than their wild-type counterparts, and this effect is Cbx7 dose-dependent. Similar results were obtained when Cbx7-null embryonic stem cells were induced to differentiate into adipocytes. Conversely, mouse embryonic fibroblasts and human adipose-derived stem cells overexpressing CBX7 show an opposite behaviour. These findings support a negative role of CBX7 in the control of adipocyte cell growth and differentiation. PMID:25190058

The relation between Ring Box-1 protein overexpression and tumor grade and stage in bladder urothelial cell carcinoma.

PubMed

Celik, Zeliha Esin; Kaynar, Mehmet; Karabagli, Pinar; Gergerlioglu, Nursadan; Goktas, Serdar

2017-12-06

Ring Box Protein-1 (RBX-1), a component of SCF E3 ubiquitin ligases, has a crucial role in bladder urothelial cell carcinoma (UCC) carcinogenesis and progression. In the present study, it is aimed to determine the expression of RBX-1 protein in bladder UCC and the association between tumor grade, stage and RBX-1 expression. Ninety UCC samples and 20 samples containing foci of normal bladder urothelium were recruited and analyzed immunohistochemically in terms of RBX-1 expression. Immuno-reactivity scoring system (IRS) was used to determine RBX-1 expression levels. RBX-1 overexpression was associated with high tumor grade (p= 0.001) and advanced stage (p= 0.001). pT1 tumors showed higher RBX-1 expression than pTa tumors. pT2 tumors showed not only higher expression than pTa tumors but also higher expression than the total of pTa and pT1 groups combined. There was no statistically significant relation between RBX-1 expression and patient gender (p= 0.116) or age (p= 0.191). In bladder UCC, RBX-1 overexpression is associated with high tumor grade and advanced stage and represents biological potential of invasiveness and aggressive disease. Results of the present study have to be supported with further studies to reveal clinical and therapeutic implications of RBX-1 overexpression in bladder UCC.

DNMT3B modulates the expression of cancer-related genes and downregulates the expression of the gene VAV3 via methylation

PubMed Central

Peralta-Arrieta, Irlanda; Hernández-Sotelo, Daniel; Castro-Coronel, Yaneth; Leyva-Vázquez, Marco Antonio; Illades-Aguiar, Berenice

2017-01-01

Altered promoter DNA methylation is one of the most important epigenetic abnormalities in human cancer. DNMT3B, de novo methyltransferase, is clearly related to abnormal methylation of tumour suppressor genes, DNA repair genes and its overexpression contributes to oncogenic processes and tumorigenesis in vivo. The purpose of this study was to assess the effect of the overexpression of DNMT3B in HaCaT cells on global gene expression and on the methylation of selected genes to the identification of genes that can be target of DNMT3B. We found that the overexpression of DNMT3B in HaCaT cells, modulate the expression of genes related to cancer, downregulated the expression of 151 genes with CpG islands and downregulated the expression of the VAV3 gene via methylation of its promoter. These results highlight the importance of DNMT3B in gene expression and human cancer. PMID:28123849

DNMT3B modulates the expression of cancer-related genes and downregulates the expression of the gene VAV3 via methylation.

PubMed

Peralta-Arrieta, Irlanda; Hernández-Sotelo, Daniel; Castro-Coronel, Yaneth; Leyva-Vázquez, Marco Antonio; Illades-Aguiar, Berenice

2017-01-01

Altered promoter DNA methylation is one of the most important epigenetic abnormalities in human cancer. DNMT3B, de novo methyltransferase, is clearly related to abnormal methylation of tumour suppressor genes, DNA repair genes and its overexpression contributes to oncogenic processes and tumorigenesis in vivo . The purpose of this study was to assess the effect of the overexpression of DNMT3B in HaCaT cells on global gene expression and on the methylation of selected genes to the identification of genes that can be target of DNMT3B. We found that the overexpression of DNMT3B in HaCaT cells, modulate the expression of genes related to cancer, downregulated the expression of 151 genes with CpG islands and downregulated the expression of the VAV3 gene via methylation of its promoter. These results highlight the importance of DNMT3B in gene expression and human cancer.

miR-203a is involved in HBx-induced inflammation by targeting Rap1a

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

Wu, AiRong; Chen, Huo; Xu, ChunFang

Hepatitis B virus (HBV) causes acute and chronic hepatitis, and is one of the major causes of cirrhosis and hepatocellular carcinoma. Accumulating evidence suggests that inflammation is the key factor for liver cirrhosis and hepatocellular carcinoma. MicroRNAs play important roles in many biological processes. Here, we aim to explore the function of microRNAs in the HBX-induced inflammation. First, microarray experiment showed that HBV{sup +} liver samples expressed higher level of miR-203a compared to HBV{sup -} liver samples. To verify these alterations, HBx-coding plasmid was transfected into HepG2 cells to overexpress HBx protein. The real-time PCR results suggested that over-expression ofmore » HBx could induce up-regulation of miR-203a. To define how up-regulation of miR-203a can induce liver cells inflammation, we over-expressed miR-203a in HepG2 cells. Annexin V staining and BrdU staining suggested that overexpression of miR-203a significantly increased the cell apoptosis and proliferation, meanwhile, over-expression of miR-203a could lead to a decrease in G0/G1 phase cells and an increase in G2/M phase cells. Some cytokines production including IL-6 and IL-8 were significantly increased, but TGFβ and IFNγ were decreased in miR-203a over-expressed HepG2 cells. Luciferase reporter assay experiments, protein mass-spectrum assay and real-time PCR all together demonstrated that Rap1a was the target gene of miR-203a. Further experiments showed that these alterations were modulated through PI3K/ERK/p38/NFκB pathways. These data suggested that HBV-infection could up-regulate the expression of miR-203a, thus down regulated the expression of Rap1a and affected the PI3K/ERK/p38/NFκB pathways, finally induced the hepatitis inflammation. - Highlights: • HBX induces the over-expression of miR-203a in HepG2 cells. • miR-203a targets Rap1a to induce the inflammation in HepG2 cells. • miR-203a regulates the apoptosis and cell cycles of HepG2 cells. • miR-203a alters the MAPK signaling pathway by down-regulating the Rap1a.« less

Expression of the pituitary stem/progenitor marker GFRα2 in human pituitary adenomas and normal pituitary

PubMed Central

Mathioudakis, Nestoras; Sundaresh, Ram; Larsen, Alexandra; Ruff, William; Schiller, Jennifer; Cázares, Hugo Guerrero; Burger, Peter; Salvatori, Roberto; Quiñones-Hinojosa, Alfredo

2014-01-01

Purpose Recent studies suggest that adult pituitary stem cells may play a role in pituitary tumorigenesis. We sought to explore whether the Glial cell-line derived neurotrophic factor receptor alpha 2 (GFRα2), a recently described pituitary stem/progenitor marker, might be differentially expressed in pituitary adenomas versus normal pituitary. Methods The expression of GFRα2 and other members of the GFR receptor family (GFRα1, α3, α4) were analyzed using RT-PCR, western blot, and immunohistochemistry in 39 pituitary adenomas, 14 normal pituitary glands obtained at autopsy, and cDNA from 3 normal pituitaries obtained commercially. Results GFRα2 mRNA was ~2.6 fold under-expressed in functioning adenomas (P <0.01) and ~3.5 fold over-expressed in non-functioning adenomas (NFAs) (P <0.05) compared to normal pituitary. Among NFAs, GFRα2 was significantly over-expressed (~5-fold) in the gonadotropinoma subtype only (P<0.05). GFRα2 protein expression appeared to be higher in most NFAs, although there was heterogeneity in protein expression in this group. GFRα2 protein expression appeared consistently lower in functioning adenomas by IHC and western blot. In normal pituitary, GFRα2 was localized in Rathke’s remnant, the putative pituitary stem cell niche, and in corticotropes. Conclusion Our results suggest that the pituitary stem cell marker GFRα2 is under-expressed in functioning adenomas and over-expressed in NFAs, specifically gonadotropinomas. Further studies are required to elucidate whether over-expression of GFRα2 in gonadotropinomas might play a role in pituitary tumorigenesis. PMID:24402129

Functional Characteristics of Tumor-Associated Protein Spot14 and Interacting Proteins in Mouse Mammary Epithelial and Breast Cancer Cell Lines

DTIC Science & Technology

2009-09-01

merely qualitative, so in order to quantify the functional effect of S14 overexpression, NMR based metabolomics was used. The literature reports that...overexpression in DIP medium, even though fatty acids were significantly increased. Due to limitations of NMR based metabolomics, the chain length of the...S14 affects glucose carbon conversion directly into fatty acids. Interestingly, glucose consumption and lactate excretion was identical in either

A receptor tyrosine kinase, UFO/Axl, and other genes isolated by a modified differential display PCR are overexpressed in metastatic prostatic carcinoma cell line DU145.

PubMed

Jacob, A N; Kalapurakal, J; Davidson, W R; Kandpal, G; Dunson, N; Prashar, Y; Kandpal, R P

1999-01-01

We have used a modified differential display PCR protocol for isolating 3' restriction fragments of cDNAs specifically expressed or overexpressed in metastatic prostate carcinoma cell line DU145. Several cDNA fragments were identified that matched to milk fat globule protein, UFO/Axl, a receptor tyrosine kinase, human homologue of a Xenopus maternal transcript, laminin and laminin receptor, human carcinoma-associated antigen, and some expressed sequence tags. The transcript for milk fat globule protein, a marker protein shown to be overexpressed in breast tumors, was elevated in DU145 cells. The expression of UFO/Axl, a receptor tyrosine kinase, was considerably higher in DU145 cells as compared to normal prostate cells and prostatic carcinoma cell line PC-3. The overexpression of UFO oncogene in DU145 cells is discussed in the context of prostate cancer metastasis.

The bHLH transcription factor BIS1 controls the iridoid branch of the monoterpenoid indole alkaloid pathway in Catharanthus roseus

PubMed Central

Van Moerkercke, Alex; Steensma, Priscille; Schweizer, Fabian; Pollier, Jacob; Gariboldi, Ivo; Payne, Richard; Vanden Bossche, Robin; Miettinen, Karel; Espoz, Javiera; Purnama, Purin Candra; Kellner, Franziska; Seppänen-Laakso, Tuulikki; O’Connor, Sarah E.; Rischer, Heiko; Memelink, Johan; Goossens, Alain

2015-01-01

Plants make specialized bioactive metabolites to defend themselves against attackers. The conserved control mechanisms are based on transcriptional activation of the respective plant species-specific biosynthetic pathways by the phytohormone jasmonate. Knowledge of the transcription factors involved, particularly in terpenoid biosynthesis, remains fragmentary. By transcriptome analysis and functional screens in the medicinal plant Catharanthus roseus (Madagascar periwinkle), the unique source of the monoterpenoid indole alkaloid (MIA)-type anticancer drugs vincristine and vinblastine, we identified a jasmonate-regulated basic helix–loop–helix (bHLH) transcription factor from clade IVa inducing the monoterpenoid branch of the MIA pathway. The bHLH iridoid synthesis 1 (BIS1) transcription factor transactivated the expression of all of the genes encoding the enzymes that catalyze the sequential conversion of the ubiquitous terpenoid precursor geranyl diphosphate to the iridoid loganic acid. BIS1 acted in a complementary manner to the previously characterized ethylene response factor Octadecanoid derivative-Responsive Catharanthus APETALA2-domain 3 (ORCA3) that transactivates the expression of several genes encoding the enzymes catalyzing the conversion of loganic acid to the downstream MIAs. In contrast to ORCA3, overexpression of BIS1 was sufficient to boost production of high-value iridoids and MIAs in C. roseus suspension cell cultures. Hence, BIS1 might be a metabolic engineering tool to produce sustainably high-value MIAs in C. roseus plants or cultures. PMID:26080427

The Mechanism of Starch Over-Accumulation in Chlamydomonas reinhardtii High-Starch Mutants Identified by Comparative Transcriptome Analysis

PubMed Central

Koo, Kwang M.; Jung, Sera; Lee, Beom S.; Kim, Jin-Baek; Jo, Yeong D.; Choi, Hong-Il; Kang, Si-Yong; Chung, Gook-H.; Jeong, Won-Joong; Ahn, Joon-Woo

2017-01-01

The focus of this study was the mechanism of starch accumulation in Chlamydomonas reinhardtii high-starch mutants. Three C. reinhardtii mutants showing high-starch content were generated using gamma irradiation. When grown under nitrogen-deficient conditions, these mutants had more than twice as much starch than a wild-type control. The mechanism of starch over-accumulation in these mutants was studied with comparative transcriptome analysis. In all mutants, induction of phosphoglucomutase 1 (PGM1) expression was detected; PGM1 catalyzes the inter-conversion of glucose 1-phosphate and glucose 6-phosphate in both starch biosynthetic and glycolytic pathway. Interestingly, transcript levels of phosphoglucose isomerase 1 (PGI1), fructose 1,6-bisphosphate aldolase 1 and 2 (FBA1 and FBA2) were down-regulated in all mutants; PGI1, FBA1, and FBA2 act on downstream of glucose 6-phosphate conversion in glycolytic pathway. Therefore, down-regulations of PGI1, FBA1, and FBA2 may lead to accumulation of upstream metabolites, notably glucose 6-phosphate, resulting in induction of PGM1 expression through feed-forward regulation and that PGM1 overexpression caused starch over-accumulation in mutants. These results suggest that PGI1, FBA1, FBA2, and PGM1 correlate with each other in terms of coordinated transcriptional regulation and play central roles for starch over-accumulation in C. reinhardtii. PMID:28588557

Arabidopsis thaliana RALF1 opposes brassinosteroid effects on root cell elongation and lateral root formation

PubMed Central

Moura, Daniel S.

2014-01-01

Rapid alkalinization factor (RALF) is a peptide signal that plays a basic role in cell biology and most likely regulates cell expansion. In this study, transgenic Arabidopsis thaliana lines with high and low levels of AtRALF1 transcripts were used to investigate this peptide’s mechanism of action. Overexpression of the root-specific isoform AtRALF1 resulted in reduced cell size. Conversely, AtRALF1 silencing increased root length by increasing the size of root cells. AtRALF1-silenced plants also showed an increase in the number of lateral roots, whereas AtRALF1 overexpression produced the opposite effect. In addition, four AtRALF1-inducible genes were identified: two genes encoding proline-rich proteins (AtPRP1 and AtPRP3), one encoding a hydroxyproline-rich glycoprotein (AtHRPG2), and one encoding a xyloglucan endotransglucosylase (TCH4). These genes were expressed in roots and involved in cell-wall rearrangement, and their induction was concentration dependent. Furthermore, AtRALF1-overexpressing plants were less sensitive to exogenous brassinolide (BL); upon BL treatment, the plants showed no increase in root length and a compromised increase in hypocotyl elongation. In addition, the treatment had no effect on the number of emerged lateral roots. AtRALF1 also induces two brassinosteroid (BR)-downregulated genes involved in the BR biosynthetic pathway: the cytochrome P450 monooxygenases CONSTITUTIVE PHOTOMORPHISM AND DWARFISM (CPD) and DWARF4 (DWF4). Simultaneous treatment with both AtRALF1 and BL caused a reduction in AtRALF1-inducible gene expression levels, suggesting that these signals may compete for components shared by both pathways. Taken together, these results indicate an opposing effect of AtRALF1 and BL, and suggest that RALF’s mechanism of action could be to interfere with the BR signalling pathway. PMID:24620000

Homeobox B9 is overexpressed in hepatocellular carcinomas and promotes tumor cell proliferation both in vitro and in vivo

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

Li, Fangyi; Dong, Lei, E-mail: dlleidong@126.com; Xing, Rong

2014-02-07

Highlights: • HOXB9 is overexpressed in human HCC samples. • HOXB9 over expression had shorter survival time than down expression. • HOXB9 stimulated the proliferation of HCC cells. • Activation of TGF-β1 contributes to HOXB9-induced proliferation in HCC cells. - Abstract: HomeoboxB9 (HOXB9), a nontransforming transcription factor that is overexpressed in multiple tumor types, alters tumor cell fate and promotes tumor progression. However, the role of HOXB9 in hepatocellular carcinoma (HCC) development has not been well studied. In this paper, we found that HOXB9 is overexpressed in human HCC samples. We investigated HOXB9 expression and its prognostic value for HCC.more » HCC surgical tissue samples were taken from 89 HCC patients. HOXB9 overexpression was observed in 65.2% of the cases, and the survival analysis showed that the HOXB9 overexpression group had significantly shorter overall survival time than the HOXB9 downexpression group. The ectopic expression of HOXB9 stimulated the proliferation of HCC cells; whereas the knockdown of HOXB9 produced an opposite effect. HOXB9 also modulated the tumorigenicity of HCC cells in vivo. Moreover, we found that the activation of TGF-β1 contributes to HOXB9-induced proliferation activities. The results provide the first evidence that HOXB9 is a critical regulator of tumor growth factor in HCC.« less

Mel-18 negatively regulates stem cell-like properties through downregulation of miR-21 in gastric cancer

PubMed Central

Hua, Rui-Xi; Du, Yi-Qun; Huang, Ming-Zhu; Liu, Yong; Cheng, Yu Fang; Guo, Wei-Jian

2016-01-01

Mel-18, a polycomb group protein, has been reported to act as a tumor suppressor and be down-regulated in several human cancers including gastric cancer. It was also found that Mel-18 negatively regulates self-renewal of hematopoietic stem cells and breast cancer stem cells (CSCs). This study aimed to clarify its role in gastric CSCs and explore the mechanisms. We found that low-expression of Mel-18 was correlated with poor prognosis and negatively correlated with overexpression of stem cell markers Oct4, Sox2, and Gli1 in 101 gastric cancer tissues. Mel-18 was down-regulated in cultured spheroid cells, which possess CSCs, and overexpression of Mel-18 inhibits cells sphere-forming ability and tumor growth in vivo. Besides, Mel-18 was lower-expressed in ovary metastatic lesions compared with that in primary lesions of gastric cancer, and Mel-18 overexpression inhibited the migration ability of gastric cancer cells. Interestingly, overexpression of Mel-18 resulted in down-regulation of miR-21 in gastric cancer cells and the expression of Mel-18 was negatively correlated with the expression of miR-21 in gastric cancer tissues. Furthermore, miR-21 overexpression partially restored sphere-forming ability, migration potential and chemo-resistance in Mel-18 overexpressing gastric cancer cells. These results suggests Mel-18 negatively regulates stem cell-like properties through downregulation of miR-21 in gastric cancer cells. PMID:27542229

Overexpression of Buffy enhances the loss of parkin and suppresses the loss of Pink1 phenotypes in Drosophila.

PubMed

M'Angale, P Githure; Staveley, Brian E

2017-03-01

Mutations in parkin (PARK2) and Pink1 (PARK6) are responsible for autosomal recessive forms of early onset Parkinson's disease (PD). Attributed to the failure of neurons to clear dysfunctional mitochondria, loss of gene expression leads to loss of nigrostriatal neurons. The Pink1/parkin pathway plays a role in the quality control mechanism aimed at eliminating defective mitochondria, and the failure of this mechanism results in a reduced lifespan and impaired locomotor ability, among other phenotypes. Inhibition of parkin or Pink1 through the induction of stable RNAi transgene in the Ddc-Gal4-expressing neurons results in such phenotypes to model PD. To further evaluate the effects of the overexpression of the Bcl-2 homologue Buffy, we analysed lifespan and climbing ability in both parkin-RNAi- and Pink1-RNAi-expressing flies. In addition, the effect of Buffy overexpression upon parkin-induced developmental eye defects was examined through GMR-Gal4-dependent expression. Curiously, Buffy overexpression produced very different effects: the parkin-induced phenotypes were enhanced, whereas the Pink1-enhanced phenotypes were suppressed. Interestingly, the overexpression of Buffy along with the inhibition of parkin in the neuron-rich eye results in the suppression of the developmental eye defects.

Forced expression of Hnf4a induces hepatic gene activation through directed differentiation.

PubMed

Yahoo, Neda; Pournasr, Behshad; Rostamzadeh, Jalal; Fathi, Fardin

2016-08-05

Embryonic stem (ES) cells are capable of unlimited self-renewal and have a diverse differentiation potential. These unique features make ES cells as an attractive source for developmental biology studies. Having the mature hepatocyte in the lab with functional activities is valuable in drug discovery studies. Overexpression of hepatocyte lineage-specific transcription factors (TFs) becomes a promising approach in pluripotent cell differentiation toward liver cells. Many studies generate transgenic ES cell lines to examine the effects of specific TFs overexpression in cell differentiation. In the present report, we have addressed whether a suspension or adherent model of differentiation is an appropriate way to study the role of Hnf4a overexpression. We generated ES cells that carried a doxycycline (Dox)-inducible Hnf4a using lentiviral vectors. The transduced cells were subjected to induced Hnf4a overexpression through both spontaneous and directed differentiation methods. Gene expression analysis showed substantially increased expression of hepatic gene markers, particularly Ttr and endogenous Hnf4a, in transduced cells differentiated by the directed approach. These results demonstrated that forced expression of TFs during directed differentiation would be an appropriate way to study relevant gene activation and the effects of overexpression in the context of hepatic differentiation. Copyright © 2016 Elsevier Inc. All rights reserved.

Stromal-Cell-Derived Factor (SDF) 1-Alpha Overexpression Promotes Bone Regeneration by Osteogenesis and Angiogenesis in Osteonecrosis of the Femoral Head.

PubMed

Yang, Fan; Xue, Feng; Guan, Junjie; Zhang, Zeng; Yin, Jimin; Kang, Qingling

2018-05-07

Osteonecrosis of the femoral head (ONFH) is a devastating orthopedic disease. Previous studies suggested that stromal-cell-derived factor (SDF)-1 was involved in osteogenesis and angiogenesis. However, whether SDF-1 potentiates the angiogenesis and osteogenesis of bone marrow-derived stromal stem cells (BMSCs) in ONFH is not clear. BMSCs were transfected with green fluorescent protein (GFP) or the fusion gene encoding GFP and SDF-1α, and transgenic efficacy was monitored by immunofluorescence. The expression of SDF-1α, runt-related transcription factor 2 (Runx2, osteocalcin (OCN), and alkaline phosphatase (ALP) at the mRNA level was measured by real-time polymerase chain reactions (RT-PCR). The expression of SDF-1α, Runx2, OCN, and p-Smad1/5 were measured at the protein level by Western blot. Transwell migration assay and tube formation assay were utilized to detect the angiogenesis in vitro, whereas the in vivo angiogenesis was monitored by angiography. Immunohistological staining and micro-CT scanning were conducted to assess the histological changes in morphology. In vitro, SDF-1α overexpression in BMSCs promoted osteogenic differentiation and upregulated the expression of osteogenic-related proteins, such as ALP, Runx2, OCN, and p-Smadl/5. In the methylprednisolone induced ONFH rat model used in our investigation, the overexpression of SDF-1α in BMSCs promoted significantly more bone regeneration and the expression of OCN and Runx2 as compared with the effect of vehicle overexpression. Moreover, the morphology of ONFH was ameliorated after the transplantation of BMSCs with SDF-1α overexpression. Furthermore, SDF-1α overexpression in BMSCs significantly increased osteoblastic angiogenesis as indicated by the increased tube formation ability, CD31 expression, and vessel volume. SDF-1α overexpression in BMSCs promotes bone generation as indicated by osteogenesis and angiogenesis, suggesting SDF-1α may serve as a therapeutic drug target for ONFH treatment. © 2018 The Author(s). Published by S. Karger AG, Basel.

MicroRNA-142-5p Overexpression Inhibits Cell Growth and Induces Apoptosis by Regulating FOXO in Hepatocellular Carcinoma Cells.

PubMed

Lou, Kexin; Chen, Ning; Li, Zhihong; Zhang, Bei; Wang, Xiuli; Chen, Ye; Xu, Haining; Wang, Dongwei; Wang, Hao

2017-01-02

Abnormal expression of microRNA (miR)-142-5p has been reported in hepatocellular carcinoma (HCC). However, little information is available regarding the functional role of miR-142-5p in HCC. We aimed to explore the effects of miR-142-5p aberrant expression on HCC cell growth and cell apoptosis, as well as the underlying mechanism. Human HCC cell lines HepG2 and SMMC-7721 cells were transfected with miR-142-5p mimic, inhibitor, or a corresponding negative control. Cell viability, cell cycle distribution, and cell apoptosis were then analyzed. In addition, protein expression of Forkhead box, class O (FOXO) 1 and 3, a Bcl-2-interacting mediator of cell death (Bim), procaspase 3, and activated caspase 3 was measured. After transfection with miR-142-5p inhibitor, FOXO1 and FOXO3 were overexpressed, and then the cell viability and cell apoptosis were determined again. The relative cell viability in both HepG2 and SMMC-7721 cells was significantly reduced by miR-142-5p overexpression (p < 0.05). miR-142-5p overexpression displayed a significant blockage at the G1/S transition and significantly increased the percentages of G0/G1 phase. Moreover, the results showed that miR-142-5p overexpression significantly induced cell apoptosis and statistically elevated the protein expression levels of FOXO1, FOXO3, Bim, procaspase 3, and activated caspase 3. However, the cells transfected with miR-142-5p inhibitor showed contrary results. Additionally, the effects of miR-142-5p inhibitor on cell viability and apoptosis were reversed by overexpression of FOXO. In conclusion, our results suggest that miR-142-5p overexpression shows an important protective role in HCC by inhibiting cell growth and inducing apoptosis. These effects might be by regulating FOXO expression in HCC cells.

Elevated Expression of IRS-1 Associates with p-Akt Expression and Predicts Poor Prognosis of Breast Invasive Ductal Carcinoma.

PubMed

Luo, Jiadi; Feng, Juan; Wen, Qiuyuan; Qoyawayma, Christopher; Wang, Weiyuan; Chen, Lingjiao; Lu, Junmi; Zhan, Yuting; Xu, Lina; Zang, Hongjing; Fan, Songqing; Chu, Shuzhou

2018-03-15

Overexpression of Insulin Receptor Substrate 1 (IRS-1) has been reported to promote cell growth, atypical hyperplasia, and carcinogenesis. And phosphorylated Akt (p-Akt) is certified to be involved in many types of cancers such as breast invasive ductal carcinoma (BIDC). However, the relationship between IRS-1 and Akt, as well as the role of expression of IRS-1 in BIDC, has never been reported. The purpose of this research is to investigate the association between expression of IRS-1 and p-Akt proteins and clinicopathological features of BIDC by immunohistochemistry, as well as the survival status. The results showed that the percentage of either elevated expression of IRS-1 or positive p-Akt expression in BIDC is significantly higher than that in control breast tissue from non-cancer patients (P<.001, P=.001, respectively). Overexpression of IRS-1 was evidently associated with positive expression of p-Akt (r=.337, P<.001). Also, positive percentage of p-Akt expression was statistically different among different molecular subtypes of BIDC (highest in luminal B BIDC, P=.009). Furthermore, significantly worse overall survival was in BIDC patients with high expression of IRS-1 and p-Akt than patients with low expression (P=.006, P=.004, respectively). The multivariate Cox proportional hazard regression analysis showed that high expression of IRS-1 and positive expression of p-Akt protein were independent poor prognostic factors for patients with BIDC (P=.022, P=.046, respectively). In conclusion, we report for the first time that overexpression of IRS-1 protein associates with expression of p-Akt, and overexpression of IRS-1 and positive expression of p-Akt might be independent biomarkers for poor prognosis in BIDC. Copyright © 2018. Published by Elsevier Inc.

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

PubMed

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

2016-10-01

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

Adenoviral overexpression of Lhx2 attenuates cell viability but does not preserve the stem cell like phenotype of hepatic stellate cells

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

Genz, Berit; Thomas, Maria; Pützer, Brigitte M.

2014-11-01

Hepatic stellate cells (HSC) are well known initiators of hepatic fibrosis. After liver cell damage, HSC transdifferentiate into proliferative myofibroblasts, representing the major source of extracellular matrix in the fibrotic organ. Recent studies also demonstrate a role of HSC as progenitor or stem cell like cells in liver regeneration. Lhx2 is described as stem cell maintaining factor in different organs and as an inhibitory transcription factor in HSC activation. Here we examined whether a continuous expression of Lhx2 in HSC could attenuate their activation and whether Lhx2 could serve as a potential target for antifibrotic gene therapy. Therefore, we evaluatedmore » an adenoviral mediated overexpression of Lhx2 in primary HSC and investigated mRNA expression patterns by qRT-PCR as well as the activation status by different in vitro assays. HSC revealed a marked increase in activation markers like smooth muscle actin alpha (αSMA) and collagen 1α independent from adenoviral transduction. Lhx2 overexpression resulted in attenuated cell viability as shown by a slightly hampered migratory and contractile phenotype of HSC. Expression of stem cell factors or signaling components was also unaffected by Lhx2. Summarizing these results, we found no antifibrotic or stem cell maintaining effect of Lhx2 overexpression in primary HSC. - Highlights: • We performed adenoviral overexpression of Lhx2 in primary hepatic stellate cells. • Hepatic stellate cells expressed stem cell markers during cultivation. • Cell migration and contractility was slightly hampered upon Lhx2 overexpression. • Lhx2 overexpression did not affect stem cell character of hepatic stellate cells.« less

Characterization of the ABA Receptor VlPYL1 That Regulates Anthocyanin Accumulation in Grape Berry Skin

PubMed Central

Gao, Zhen; Li, Qin; Li, Jing; Chen, Yujin; Luo, Meng; Li, Hui; Wang, Jiyuan; Wu, Yusen; Duan, Shuyan; Wang, Lei; Song, Shiren; Xu, Wenping; Zhang, Caixi; Wang, Shiping; Ma, Chao

2018-01-01

ABA plays a crucial role in controlling several ripening-associated processes in grape berries. The soluble proteins named as PYR (pyrabactin resistant)/PYL (PYR-like)/RCAR (regulatory component of ABA receptor) family have been characterized as ABA receptors. Here, the function of a grape PYL1 encoding gene involved in the response to ABA was verified through heterologous expression. The expression level of VlPYL1 was highest in grape leaf and fruit tissues of the cultivar Kyoho, and the expression of VlPYL1 was increased during fruit development and showed a reduction in ripe berries. Over-expression of VlPYL1 enhances ABA sensitivity in Arabidopsis. Using the transient overexpression technique, the VlPYL1 gene was over-expressed in grape berries. Up-regulation of the VlPYL1 gene not only promoted anthocyanin accumulation but also induced a set of ABA-responsive gene transcripts, including ABF2 and BG3. Although tobacco rattle virus (TRV)-induced gene silencing (VIGS) was not successfully applied in the “Kyoho” grape, the application of the transient overexpression technique in grape fruit could be used as a novel tool for studying grape fruit development. PMID:29868057

MiR-300 suppresses laryngeal squamous cell carcinoma proliferation and metastasis by targeting ROS1.

PubMed

Ge, Wensheng; Han, Chaodong; Wang, Jing; Zhang, Yunping

2016-01-01

Laryngeal squamous cell carcinoma (LSCC) is a common aggressive head and neck cancer with high mortality and incidence. MicroRNAs (miRNAs) are short, non-coding and endogenous RNAs that posttranscriptionally inhibit gene expression. In this study, we showed that miR-300 expression was downregulated in LSCC tissues compared with adjacent no-tumor tissues. MiR-300 overexpression inhibited Hep-2 cell proliferation, as well as the expression of ki-67 and PCNA. Moreover, overexpression of miR-300 repressed the cell invasion in Hep-2 cells. We identified c-ros oncogene 1 receptor tyrosine kinase (ROS1) as a direct target gene of miR-300 in Hep-2 cell. Furthermore, ROS1 expression was upregulated in LSCC tissues compared with adjacent no-tumor tissues. Interesting, there were an inverse correlation between ROS1 and miR-300 expression in the LSCC tissues. Overexpression of ROS1 increased the Hep-2 cells proliferation and invasion. Overexpression of ROS1 abrogated miR-300 induced cell growth and invasion inhibition. Therefore, our data suggested that miR-300 acted as a tumor suppressive gene in LSCC.

MiR-300 suppresses laryngeal squamous cell carcinoma proliferation and metastasis by targeting ROS1

PubMed Central

Ge, Wensheng; Han, Chaodong; Wang, Jing; Zhang, Yunping

2016-01-01

Laryngeal squamous cell carcinoma (LSCC) is a common aggressive head and neck cancer with high mortality and incidence. MicroRNAs (miRNAs) are short, non-coding and endogenous RNAs that posttranscriptionally inhibit gene expression. In this study, we showed that miR-300 expression was downregulated in LSCC tissues compared with adjacent no-tumor tissues. MiR-300 overexpression inhibited Hep-2 cell proliferation, as well as the expression of ki-67 and PCNA. Moreover, overexpression of miR-300 repressed the cell invasion in Hep-2 cells. We identified c-ros oncogene 1 receptor tyrosine kinase (ROS1) as a direct target gene of miR-300 in Hep-2 cell. Furthermore, ROS1 expression was upregulated in LSCC tissues compared with adjacent no-tumor tissues. Interesting, there were an inverse correlation between ROS1 and miR-300 expression in the LSCC tissues. Overexpression of ROS1 increased the Hep-2 cells proliferation and invasion. Overexpression of ROS1 abrogated miR-300 induced cell growth and invasion inhibition. Therefore, our data suggested that miR-300 acted as a tumor suppressive gene in LSCC. PMID:27725869

MicroRNA-29c overexpression inhibits proliferation and promotes apoptosis and differentiation in P19 embryonal carcinoma cells.

PubMed

Liu, Ming; Chen, Yumei; Song, Guixian; Chen, Bin; Wang, Lihua; Li, Xing; Kong, Xiangqing; Shen, Yahui; Qian, Lingmei

2016-01-15

Compared to healthy controls, microRNA-29c (miR-29c) is highly expressed in the heart during progression towards ventricular septal defect. However, studies on miR-29c function in heart development are scarce. We investigated the role of miR-29c in P19 cell proliferation, apoptosis, and differentiation and the underlying mechanisms. We evaluated proliferation and cell cycle progression, detected morphological changes; apoptosis rate; BAX, BCL2, GATA binding protein 4 (GATA4), cardiac troponin T (cTnT), and myocyte enhancer factor 2C (MEF2C) expression; and caspase-3, -8, and -9 activity in miR-29c-overexpressing P19 cells, and investigated whether WNT4 was a miR-29c target. MiR-29c-overexpressing cells had decreased proliferation, increased G1 cells, and significantly higher apoptotic rate than the controls. Expression of the apoptosis-related BAX and BCL2 genes and caspase-3, -8, and -9 activity were significantly increased in miR-29c-overexpressing cells. Expression of the cardiac-specific markers GATA4, cTnT, and MEF2C revealed promoted differentiation in miR-29c-overexpressing cells compared to the controls. Luciferase assay confirmed that WNT4 is a miR-29c target. Wnt4 and β-catenin expression was decreased in miR-29c-overexpressing cells. MiR-29c inhibits P19 cell proliferation and promotes apoptosis and differentiation, possibly by suppressing Wnt4 signaling, whose deregulation contributes to congenital heart disease development. Copyright © 2015 Elsevier B.V. All rights reserved.

MiR-143 enhances the antitumor activity of shikonin by targeting BAG3 expression in human glioblastoma stem cells.

PubMed

Liu, Jing; Qu, Cheng-Bin; Xue, Yi-Xue; Li, Zhen; Wang, Ping; Liu, Yun-hui

Therapeutic applications of microRNAs (miRNAs) in chemotherapy were confirmed to be valuable, but there is rare to identify their specific roles and functions in shikonin treatment toward tumors. Here, for the first time, we reported that miR-143 played a critical role in the antitumor activity of shikonin in glioblastoma stem cells (GSCs). The results showed that the expression of miR-143 was downregulated in shikonin treated GSCs within 24 h. MiR-143 overexpression significantly enhanced the inhibitory effect of shikonin toward GSCs on cell viability. Besides, miR-143 overexpression caused a significant increase in the apoptotic fraction and made apoptosis occur earlier. Further investigation identified that BAG3, an apoptotic regulator, was a functional target of miR-143 in shikonin treated GSCs. The expression of BAG3 was upregulated in shikonin treated GSCs within 24 h. MiR-143 overexpression significantly reversed the high expression of BAG3 in shikonin treated GSCs. Moreover, it was confirmed that the enhanced cytotoxicity of shikonin by miR-143 overexpression was reversed by BAG3 overexpression both in vitro and in vivo, suggesting that the enhanced tumor suppressive effects by miR-143 overexpression was at least partly through the regulation of BAG3. Taken together, for the first time, our results demonstrate that miR-143 could enhance the antitumor activity of shikonin toward GSCs through reducing BAG3 expression, which may provide a novel therapeutic strategy for enhancing the treatment efficacy of shikonin toward GSCs. Copyright © 2015 Elsevier Inc. All rights reserved.

ERAP1 overexpression in HPV-induced malignancies: A possible novel immune evasion mechanism.

PubMed

Steinbach, Alina; Winter, Jan; Reuschenbach, Miriam; Blatnik, Renata; Klevenz, Alexandra; Bertrand, Miriam; Hoppe, Stephanie; von Knebel Doeberitz, Magnus; Grabowska, Agnieszka K; Riemer, Angelika B

2017-01-01

Immune evasion of tumors poses a major challenge for immunotherapy. For human papillomavirus (HPV)-induced malignancies, multiple immune evasion mechanisms have been described, including altered expression of antigen processing machinery (APM) components. These changes can directly influence epitope presentation and thus T-cell responses against tumor cells. To date, the APM had not been studied systematically in a large array of HPV + tumor samples. Therefore in this study, systematic expression analysis of the APM was performed on the mRNA and protein level in a comprehensive collection of HPV16 + cell lines. Subsequently, HPV + cervical tissue samples were examined by immunohistochemistry. ERAP1 (endoplasmic reticulum aminopeptidase 1) was the only APM component consistently altered - namely overexpressed - in HPV16 + tumor cell lines. ERAP1 was also found to be overexpressed in cervical intraepithelial neoplasia and cervical cancer samples; expression levels were increasing with disease stage. On the functional level, the influence of ERAP1 expression levels on HPV16 E7-derived epitope presentation was investigated by mass spectrometry and in cytotoxicity assays with HPV16-specific T-cell lines. ERAP1 overexpression did not cause a complete destruction of any of the HPV epitopes analyzed, however, an influence of ERAP1 overexpression on the presentation levels of certain HPV epitopes could be demonstrated by HPV16-specific CD8 + T-cells. These showed enhanced killing toward HPV16 + CaSki cells whose ERAP1 expression had been attenuated to normal levels. ERAP1 overexpression may thus represent a novel immune evasion mechanism in HPV-induced malignancies, in cases when presentation of clinically relevant epitopes is reduced by overactivity of this peptidase.

Functional analysis of rice HOMEOBOX4 (Oshox4) gene reveals a negative function in gibberellin responses.

PubMed

Dai, Mingqiu; Hu, Yongfeng; Ma, Qian; Zhao, Yu; Zhou, Dao-Xiu

2008-02-01

The homeodomain-leucine zipper (HD-Zip) putative transcription factor genes are divided into 4 families. In this work, we studied the function of a rice HD-Zip I gene, H OME O BO X4 (Oshox4). Oshox4 transcripts were detected in leaf and floral organ primordia but excluded from the shoot apical meristem and the protein was nuclear localized. Over-expression of Oshox4 in rice induced a semi-dwarf phenotype that could not be complemented by applied GA3. The over-expression plants accumulated elevated levels of bioactive GA, while the GA catabolic gene GA2ox3 was upregulated in the transgenic plants. In addition, over-expression of Oshox4 blocked GA-dependent alpha-amylase production. However, down-regulation of Oshox4 in RNAi transgenic plants induced no phenotypic alteration. Interestingly, the expression of YAB1 that is involved in the negative feedback regulation of the GA biosynthesis was upregulated in the Oshox4 over-expressing plants. One-hybrid assays showed that Oshox4 could interact with YAB1 promoter in yeast. In addition, Oshox4 expression was upregulated by GA. These data together suggest that Oshox4 may be involved in the negative regulation of GA signalling and may play a role to fine tune GA responses in rice.

A novel ethylene responsive factor CitERF13 plays a role in photosynthesis regulation.

PubMed

Xie, Xiu-Lan; Xia, Xiao-Jian; Kuang, Sheng; Zhang, Xi-Li; Yin, Xue-Ren; Yu, Jing-Quan; Chen, Kun-Song

2017-03-01

Ethylene responsive factors (ERFs) act as critical downstream components of the ethylene signalling pathway in regulating plant development and stress responses. However little is known about its role in regulation of photosynthesis. Here, we identified an ethylene-inducible ERF gene in citrus, CitERF13. Transient over-expression of CitERF13 in N. tabacum leaves, resulted in a significant decrease in net photosynthetic rate. Closer examination of photosynthetic activity of PSII and PSI indicated that CitERF13 overexpression led to declines of F v /F m , Y(II) and Y(I). However, change in NPQ was less pronounced. CitERF13 overexpression also significantly reduced V c,max , J max and AQY, indicating inhibition of the Calvin cycle. The expression of photosynthesis-related genes was suppressed to a variable extent in leaf blades transiently over-expressing CitERF13. CitERF13 transient overexpression in tobacco or citrus both resulted in a decline of Chlorophyll content and CitERF13 overexpressing tobacco leaf disc was more susceptible to chlorosis in response to MV-mediated oxidative stress. The results suggest that CitERF13 is potentially involved in suppressing photosynthesis through multiple pathways, for instance, inhibiting photochemical activity of photosynthesis, CO 2 carboxylation capacity and chlorophyll metabolism. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

AmyR Is a Novel Negative Regulator of Amylovoran Production in Erwinia amylovora

PubMed Central

Wang, Dongping; Korban, Schuyler S.; Pusey, P. Lawrence; Zhao, Youfu

2012-01-01

In this study, we attempted to understand the role of an orphan gene amyR in Erwinia amylovora, a functionally conserved ortholog of ybjN in Escherichia coli, which has recently been characterized. Amylovoran, a high molecular weight acidic heteropolymer exopolysaccharide, is a virulent factor of E. amylovora. As reported earlier, amylovoran production in an amyR knockout mutant was about eight-fold higher than that in the wild type (WT) strain of E. amylovora. When a multicopy plasmid containing the amyR gene was introduced into the amyR mutant or WT strains, amylovoran production was strongly inhibited. Furthermore, amylovoran production was also suppressed in various amylovoran-over-producing mutants, such as grrSA containing multicopies of the amyR gene. Consistent with amylovoran production, an inverse correlation was observed between in vitro expression of amyR and that of amylovoran biosynthetic genes. However, both the amyR knockout mutant and over-expression strains showed reduced levan production, another exopolysaccharide produced by E. amylovora. Virulence assays demonstrated that while the amyR mutant was capable of inducing slightly greater disease severity than that of the WT strain, strains over-expressing the amyR gene did not incite disease on apple shoots or leaves, and only caused reduced disease on immature pear fruits. Microarray studies revealed that amylovoran biosynthesis and related membrane protein-encoding genes were highly expressed in the amyR mutant, but down-regulated in the amyR over-expression strains in vitro. Down-regulation of amylovoran biosynthesis genes in the amyR over-expression strain partially explained why over-expression of amyR led to non-pathogenic or reduced virulence in vivo. These results suggest that AmyR plays an important role in regulating exopolysaccharide production, and thus virulence in E. amylovora. PMID:23028751

AmyR is a novel negative regulator of amylovoran production in Erwinia amylovora.

PubMed

Wang, Dongping; Korban, Schuyler S; Pusey, P Lawrence; Zhao, Youfu

2012-01-01

In this study, we attempted to understand the role of an orphan gene amyR in Erwinia amylovora, a functionally conserved ortholog of ybjN in Escherichia coli, which has recently been characterized. Amylovoran, a high molecular weight acidic heteropolymer exopolysaccharide, is a virulent factor of E. amylovora. As reported earlier, amylovoran production in an amyR knockout mutant was about eight-fold higher than that in the wild type (WT) strain of E. amylovora. When a multicopy plasmid containing the amyR gene was introduced into the amyR mutant or WT strains, amylovoran production was strongly inhibited. Furthermore, amylovoran production was also suppressed in various amylovoran-over-producing mutants, such as grrSA containing multicopies of the amyR gene. Consistent with amylovoran production, an inverse correlation was observed between in vitro expression of amyR and that of amylovoran biosynthetic genes. However, both the amyR knockout mutant and over-expression strains showed reduced levan production, another exopolysaccharide produced by E. amylovora. Virulence assays demonstrated that while the amyR mutant was capable of inducing slightly greater disease severity than that of the WT strain, strains over-expressing the amyR gene did not incite disease on apple shoots or leaves, and only caused reduced disease on immature pear fruits. Microarray studies revealed that amylovoran biosynthesis and related membrane protein-encoding genes were highly expressed in the amyR mutant, but down-regulated in the amyR over-expression strains in vitro. Down-regulation of amylovoran biosynthesis genes in the amyR over-expression strain partially explained why over-expression of amyR led to non-pathogenic or reduced virulence in vivo. These results suggest that AmyR plays an important role in regulating exopolysaccharide production, and thus virulence in E. amylovora.

Over-expression in Escherichia coli, purification and reconstitution in liposomes of the third member of the OCTN sub-family: The mouse carnitine transporter OCTN3

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

Scalise, Mariafrancesca; Galluccio, Michele; Pochini, Lorena

2012-05-25

Highlights: Black-Right-Pointing-Pointer mOCTN3 transport protein has been cloned in pET-21a(+) and over-expressed in Escherichia coli. Black-Right-Pointing-Pointer The expressed mOCTN3 has been purified to homogeneity by Ni-chelating chromatography. Black-Right-Pointing-Pointer The protein solubilised in Triton X-100 has been reconstituted in liposomes. Black-Right-Pointing-Pointer Recombinant mOCTN3 catalyses transport of carnitine by a uniport mode. -- Abstract: pET-21a(+)-mOCTN3-6His was constructed and used for over-expression in Escherichia coli Rosetta(DE3)pLysS. After IPTG induction a protein with apparent molecular mass of 53 kDa was collected in the insoluble fraction of the cell lysate and purified by Ni{sup 2+}-chelating chromatography with a yield of 2 mg/l of cell culture.more » The over-expressed protein was identified with mOCTN3 by anti-His antibody and reconstitution in liposomes. mOCTN3 required peculiar conditions for optimal expression and reconstitution in liposomes. The protein catalyzed a time dependent [{sup 3}H]carnitine uptake which was stimulated by intraliposomal ATP and nearly independent of the pH. The K{sub m} for carnitine was 36 {mu}M. [{sup 3}H]carnitine transport was inhibited by carnitine analogues and some Cys and NH{sub 2} reagents. This paper represents the first outcome in over-expressing, in active form, the third member of the OCTN sub-family, mOCTN3, in E. coli.« less

Coexistence of the loss of heterozygosity at the PTEN locus and HER2 overexpression enhances the Akt activity thus leading to a negative progesterone receptor expression in breast carcinoma.

PubMed

Tokunaga, Eriko; Oki, Eiji; Kimura, Yasue; Yamanaka, Takeharu; Egashira, Akinori; Nishida, Kojiro; Koga, Tadashi; Morita, Masaru; Kakeji, Yoshihiro; Maehara, Yoshihiko

2007-03-01

Serine/threonine kinase Akt/PKB is known to regulate divergent cellular processes, including apoptosis, proliferation, differentiation, and metabolism. Akt is activated by a variety of stimuli, through such growth factor receptors as HER2, in phosphoinositide-3-OH kinase (PI3K)-dependent manner. A loss of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) function also activates Akt. It has recently been shown that Akt activation is associated with a worse outcome among endocrine treated breast cancer patients and that it also inhibits the progesterone receptor (PR) expression via the PI3K/Akt pathway in breast cancer cells. Therefore, the PI3K/Akt signaling pathway has recently attracted considerable attention as a new target for effective therapeutic strategies. In the present study, we investigated the relationship between Akt activation and either HER2 overexpression or PTEN gene alteration, as well as the PR expression. We analyzed the incidence of LOH at the PTEN locus in 138 breast cancer patients, using our new system for microsatellite analysis, called high-resolution fluorescent microsatellite analysis (HRFMA). We showed Akt activation to significantly correlate with HER2 overexpression or LOH at the PTEN gene locus while inversely correlating with the PR expression. In addition, when LOH at the PTEN gene locus and HER2 overexpression occurred simultaneously, the incidence of Akt activation and reduced PR expression was significant. The association between Akt activation and PR negative expression was observed even in the ER-positive cases. Our results suggest that simultaneous PTEN LOH and HER2 overexpression enhances Akt activation and may thus lead to a negative PR expression.

Macrophage migration inhibitory factor induces epithelial to mesenchymal transition, enhances tumor aggressiveness and predicts clinical outcome in resected pancreatic ductal adenocarcinoma.

PubMed

Funamizu, Naotake; Hu, Chaoxin; Lacy, Curtis; Schetter, Aaron; Zhang, Geng; He, Peijun; Gaedcke, Jochen; Ghadimi, Michael B; Ried, Thomas; Yfantis, Harris G; Lee, Dong H; Subleski, Jeffrey; Chan, Tim; Weiss, Jonathan M; Back, Timothy C; Yanaga, Katsuhiko; Hanna, Nader; Alexander, H Richard; Maitra, Anirban; Hussain, S Perwez

2013-02-15

MIF is a proinflammatory cytokine and is implicated in cancer. A higher MIF level is found in many human cancer and cancer-prone inflammatory diseases, including chronic pancreatitis and pancreatic cancer. We tested the hypothesis that MIF contributes to pancreatic cancer aggressiveness and predicts disease outcome in resected cases. Consistent with our hypothesis we found that an elevated MIF mRNA expression in tumors was significantly associated with poor outcome in resected cases. Multivariate Cox-regression analysis further showed that MIF is independently associated with patients' survival (HR = 2.26, 95% CI = 1.17-4.37, p = 0.015). Mechanistic analyses revealed that MIF overexpression decreased E-cadherin and increased vimentin mRNA and protein levels in pancreatic cancer cell lines, consistent with the features of epithelial-to-mesenchymal transition (EMT). Furthermore, MIF-overexpression significantly increased ZEB1/2 and decreased miR-200b expression, while shRNA-mediated inhibition of MIF increased E-cadherin and miR-200b expression, and reduced the expression of ZEB1/2 in Panc1 cells. Re-expression of miR-200b in MIF overexpressing cells restored the epithelial characteristics, as indicated by an increase in E-cadherin and decrease in ZEB1/2 and vimentin expression. A reduced sensitivity to the chemotherapeutic drug, gemcitabine, occurred in MIF-overexpressing cells. Indicative of an increased malignant potential, MIF over-expressing cells showed significant increase in their invasion ability in vitro, and tumor growth and metastasis in an orthotopic xenograft mouse model. These results support a role of MIF in disease aggressiveness, indicating its potential usefulness as a candidate target for designing improved treatment in pancreatic cancer. Copyright © 2012 UICC.

Roles of Soybean Plasma Membrane Intrinsic Protein GmPIP2;9 in Drought Tolerance and Seed Development.

PubMed

Lu, Linghong; Dong, Changhe; Liu, Ruifang; Zhou, Bin; Wang, Chuang; Shou, Huixia

2018-01-01

Aquaporins play an essential role in water uptake and transport in vascular plants. The soybean genome contains a total of 22 plasma membrane intrinsic protein (PIP) genes. To identify candidate PIPs important for soybean yield and stress tolerance, we studied the transcript levels of all 22 soybean PIPs. We found that a GmPIP2 subfamily member, GmPIP2;9, was predominately expressed in roots and developing seeds. Here, we show that GmPIP2;9 localized to the plasma membrane and had high water channel activity when expressed in Xenopus oocytes. Using transgenic soybean plants expressing a native GmPIP2;9 promoter driving a GUS-reporter gene, it was found high GUS expression in the roots, in particular, in the endoderm, pericycle, and vascular tissues of the roots of transgenic plants. In addition, GmPIP2;9 was also highly expressed in developing pods. GmPIP2;9 expression significantly increased in short term of polyethylene glycol (PEG)-mediated drought stress treatment. GmPIP2;9 overexpression increased tolerance to drought stress in both solution cultures and soil plots. Drought stress in combination with GmPIP2;9 overexpression increased net CO 2 assimilation of photosynthesis, stomata conductance, and transpiration rate, suggesting that GmPIP2;9- overexpressing transgenic plants were less stressed than wild-type (WT) plants. Furthermore, field experiments showed that GmPIP2;9 -overexpressing plants had significantly more pod numbers and larger seed sizes than WT plants. In summary, the study demonstrated that GmPIP2;9 has water transport activity. Its relative high expression levels in roots and developing pods are in agreement with the phenotypes of GmPIP2;9 -overexpressing plants in drought stress tolerance and seed development.

Roles of Soybean Plasma Membrane Intrinsic Protein GmPIP2;9 in Drought Tolerance and Seed Development

PubMed Central

Lu, Linghong; Dong, Changhe; Liu, Ruifang; Zhou, Bin; Wang, Chuang; Shou, Huixia

2018-01-01

Aquaporins play an essential role in water uptake and transport in vascular plants. The soybean genome contains a total of 22 plasma membrane intrinsic protein (PIP) genes. To identify candidate PIPs important for soybean yield and stress tolerance, we studied the transcript levels of all 22 soybean PIPs. We found that a GmPIP2 subfamily member, GmPIP2;9, was predominately expressed in roots and developing seeds. Here, we show that GmPIP2;9 localized to the plasma membrane and had high water channel activity when expressed in Xenopus oocytes. Using transgenic soybean plants expressing a native GmPIP2;9 promoter driving a GUS-reporter gene, it was found high GUS expression in the roots, in particular, in the endoderm, pericycle, and vascular tissues of the roots of transgenic plants. In addition, GmPIP2;9 was also highly expressed in developing pods. GmPIP2;9 expression significantly increased in short term of polyethylene glycol (PEG)-mediated drought stress treatment. GmPIP2;9 overexpression increased tolerance to drought stress in both solution cultures and soil plots. Drought stress in combination with GmPIP2;9 overexpression increased net CO2 assimilation of photosynthesis, stomata conductance, and transpiration rate, suggesting that GmPIP2;9-overexpressing transgenic plants were less stressed than wild-type (WT) plants. Furthermore, field experiments showed that GmPIP2;9-overexpressing plants had significantly more pod numbers and larger seed sizes than WT plants. In summary, the study demonstrated that GmPIP2;9 has water transport activity. Its relative high expression levels in roots and developing pods are in agreement with the phenotypes of GmPIP2;9-overexpressing plants in drought stress tolerance and seed development. PMID:29755491

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.

SOX15 regulates proliferation and migration of endometrial cancer cells.

PubMed

Rui, Xiaohui; Xu, Yun; Jiang, Xiping; Guo, Caixia; Jiang, Jingting

2017-10-31

The study aimed to investigate the effects of Sry-like high mobility group box 15 ( SOX15 ) on proliferation and migration of endometrial cancer (EC) cells. Immunohistochemistry (IHC) was applied to determine the expression of SOX15 in EC tissues and adjacent tissues. We used cell transfection method to construct the HEC-1-A and Ishikawa cell lines with stable overexpression and low expression SOX15 Reverse-transcription quantitative real-time PCR (RT-qPCR) and Western blot were performed to examine expression of SOX15 mRNA and SOX15 protein, respectively. By conducting a series of cell proliferation assay and migration assay, we analyzed the influence of SOX15 overexpression or low expression on EC cell proliferation and migration. The expression of SOX15 mRNA and protein in EC tissues was significantly lower than that in adjacent tissues. After lentivirus-transfecting SOX15 , the expression level of SOX15 mRNA and protein was significantly increased in cells of SOX15 group, and decreased in sh- SOX15 group. Overexpression of SOX15 could suppress cell proliferation, while down-regulation of SOX15 increased cell proliferation. Flow cytometry results indicated that overexpression of SOX15 induced the ratio of cell-cycle arrest in G 1 stage. In addition, Transwell migration assay results showed that SOX15 overexpression significantly inhibited cell migration, and also down-regulation of SOX15 promoted the migration. As a whole, SOX15 could regulate the proliferation and migration of EC cells and up- regulation of SOX15 could be valuable for EC treatment. © 2017 The Author(s).

Influenza A Virus Dysregulates Host Histone Deacetylase 1 That Inhibits Viral Infection in Lung Epithelial Cells

PubMed Central

Nagesh, Prashanth Thevkar

2016-01-01

ABSTRACT Viruses dysregulate the host factors that inhibit virus infection. Here, we demonstrate that human enzyme, histone deacetylase 1 (HDAC1) is a new class of host factor that inhibits influenza A virus (IAV) infection, and IAV dysregulates HDAC1 to efficiently replicate in epithelial cells. A time-dependent decrease in HDAC1 polypeptide level was observed in IAV-infected cells, reducing to <50% by 24 h of infection. A further depletion (97%) of HDAC1 expression by RNA interference increased the IAV growth kinetics, increasing it by >3-fold by 24 h and by >6-fold by 48 h of infection. Conversely, overexpression of HDAC1 decreased the IAV infection by >2-fold. Likewise, a time-dependent decrease in HDAC1 activity, albeit with slightly different kinetics to HDAC1 polypeptide reduction, was observed in infected cells. Nevertheless, a further inhibition of deacetylase activity increased IAV infection in a dose-dependent manner. HDAC1 is an important host deacetylase and, in addition to its role as a transcription repressor, HDAC1 has been lately described as a coactivator of type I interferon response. Consistent with this property, we found that inhibition of deacetylase activity either decreased or abolished the phosphorylation of signal transducer and activator of transcription I (STAT1) and expression of interferon-stimulated genes, IFITM3, ISG15, and viperin in IAV-infected cells. Furthermore, the knockdown of HDAC1 expression in infected cells decreased viperin expression by 58% and, conversely, the overexpression of HDAC1 increased it by 55%, indicating that HDAC1 is a component of IAV-induced host type I interferon antiviral response. IMPORTANCE Influenza A virus (IAV) continues to significantly impact global public health by causing regular seasonal epidemics, occasional pandemics, and zoonotic outbreaks. IAV is among the successful human viral pathogens that has evolved various strategies to evade host defenses, prevent the development of a universal vaccine, and acquire antiviral drug resistance. A comprehensive knowledge of IAV-host interactions is needed to develop a novel and alternative anti-IAV strategy. Host produces a variety of factors that are able to fight IAV infection by employing various mechanisms. However, the full repertoire of anti-IAV host factors and their antiviral mechanisms has yet to be identified. We have identified here a new host factor, histone deacetylase 1 (HDAC1) that inhibits IAV infection. We demonstrate that HDAC1 is a component of host innate antiviral response against IAV, and IAV undermines HDAC1 to limit its role in antiviral response. PMID:26912629

MiR-29-mediated elastin down-regulation contributes to inorganic phosphorus-induced osteoblastic differentiation in vascular smooth muscle cells.

PubMed

Sudo, Ryo; Sato, Fumiaki; Azechi, Takuya; Wachi, Hiroshi

2015-12-01

Vascular calcification increases the risk of cardiovascular mortality. We previously reported that expression of elastin decreases with progression of inorganic phosphorus (Pi)-induced vascular smooth muscle cell (VSMC) calcification. However, the regulatory mechanisms of elastin mRNA expression during vascular calcification remain unclear. MicroRNA-29 family members (miR-29a, b and c) are reported to mediate elastin mRNA expression. Therefore, we aimed to determine the effect of miR-29 on elastin expression and Pi-induced vascular calcification. Calcification of human VSMCs was induced by Pi and evaluated measuring calcium deposition. Pi stimulation promoted Ca deposition and suppressed elastin expression in VSMCs. Knockdown of elastin expression by shRNA also promoted Pi-induced VSMC calcification. Elastin pre-mRNA measurements indicated that Pi stimulation suppressed elastin expression without changing transcriptional activity. Conversely, Pi stimulation increased miR-29a and miR-29b expression. Inhibition of miR-29 recovered elastin expression and suppressed calcification in Pi-treated VSMCs. Furthermore, over-expression of miR-29b promoted Pi-induced VSMC calcification. RT-qPCR analysis showed knockdown of elastin expression in VSMCs induced expression of osteoblast-related genes, similar to Pi stimulation, and recovery of elastin expression by miR-29 inhibition reduced their expression. Our study shows that miR-29-mediated suppression of elastin expression in VSMCs plays a pivotal role in osteoblastic differentiation leading to vascular calcification. © 2015 The Molecular Biology Society of Japan and Wiley Publishing Asia Pty Ltd.

Sialylation of EGFR by the ST6Gal-I sialyltransferase promotes EGFR activation and resistance to gefitinib-mediated cell death.

PubMed

Britain, Colleen M; Holdbrooks, Andrew T; Anderson, Joshua C; Willey, Christopher D; Bellis, Susan L

2018-02-05

The ST6Gal-I sialyltransferase is upregulated in numerous cancers, and high expression of this enzyme correlates with poor patient prognosis in various malignancies, including ovarian cancer. Through its sialylation of a select cohort of cell surface receptors, ST6Gal-I modulates cell signaling to promote tumor cell survival. The goal of the present study was to investigate the influence of ST6Gal-I on another important receptor that controls cancer cell behavior, EGFR. Additionally, the effect of ST6Gal-I on cancer cells treated with the common EGFR inhibitor, gefitinib, was evaluated. Using the OV4 ovarian cancer cell line, which lacks endogenous ST6Gal-I expression, a kinomics assay revealed that cells with forced overexpression of ST6Gal-I exhibited increased global tyrosine kinase activity, a finding confirmed by immunoblotting whole cell lysates with an anti-phosphotyrosine antibody. Interestingly, the kinomics assay suggested that one of the most highly activated tyrosine kinases in ST6Gal-I-overexpressing OV4 cells was EGFR. Based on these findings, additional analyses were performed to investigate the effect of ST6Gal-I on EGFR activation. To this end, we utilized, in addition to OV4 cells, the SKOV3 ovarian cancer cell line, engineered with both ST6Gal-I overexpression and knockdown, as well as the BxPC3 pancreatic cancer cell line with knockdown of ST6Gal-I. In all three cell lines, we determined that EGFR is a substrate of ST6Gal-I, and that the sialylation status of EGFR directly correlates with ST6Gal-I expression. Cells with differential ST6Gal-I expression were subsequently evaluated for EGFR tyrosine phosphorylation. Cells with high ST6Gal-I expression were found to have elevated levels of basal and EGF-induced EGFR activation. Conversely, knockdown of ST6Gal-I greatly attenuated EGFR activation, both basally and post EGF treatment. Finally, to illustrate the functional importance of ST6Gal-I in regulating EGFR-dependent survival, cells were treated with gefitinib, an EGFR inhibitor widely used for cancer therapy. These studies showed that ST6Gal-I promotes resistance to gefitinib-mediated apoptosis, as measured by caspase activity assays. Results herein indicate that ST6Gal-I promotes EGFR activation and protects against gefitinib-mediated cell death. Establishing the tumor-associated ST6Gal-I sialyltransferase as a regulator of EGFR provides novel insight into the role of glycosylation in growth factor signaling and chemoresistance.

Overexpression of adenylate cyclase-associated protein 2 is a novel prognostic marker in malignant melanoma.

PubMed

Masugi, Yohei; Tanese, Keiji; Emoto, Katsura; Yamazaki, Ken; Effendi, Kathryn; Funakoshi, Takeru; Mori, Mariko; Sakamoto, Michiie

2015-12-01

Malignant melanoma is one of the lethal malignant tumors worldwide. Previously we reported that adenylate cyclase-associated protein 2 (CAP2), which is a well-conserved actin regulator, was overexpressed in hepatocellular carcinoma; however, CAP2 expression in other clinical cancers remains unclear. The aim of the current study was to clarify the clinicopathological significance of CAP2 overexpression in malignant melanoma. Immunohistochemical analyses revealed that many melanoma cells exhibited diffuse cytoplasmic expression of CAP2, whereas no normal melanocytes showed detectable immunostaining for CAP2. A high level of CAP2 expression was seen in 14 of 50 melanomas and was significantly correlated with greater tumor thickness and nodular melanoma subtypes. In addition, a high level of CAP2 expression was associated with poor overall survival in univariate and multivariate analyses. For 13 patients, samples of primary and metastatic melanoma tissue were available: four patients exhibited higher levels of CAP2 expression in metastatic tumor compared to the primary site, whereas no patient showed lower levels of CAP2 expression in metastatic melanomas. Our findings show that CAP2 overexpression is a novel prognostic marker in malignant melanoma and that CAP2 expression seems to increase stepwise during tumor progression, suggesting the involvement of CAP2 in the aggressive behavior of malignant melanoma. © 2015 Japanese Society of Pathology and Wiley Publishing Asia Pty Ltd.

GPX2 overexpression indicates poor prognosis in patients with hepatocellular carcinoma.

PubMed

Liu, Ting; Kan, Xue-Feng; Ma, Charlie; Chen, Li-Li; Cheng, Tian-Tian; Zou, Zhen-Wei; Li, Yong; Cao, Feng-Jun; Zhang, Wen-Jie; Yao, Jing; Li, Pin-Dong

2017-06-01

Glutathione peroxidase 2 has important role of tumor progression in lots of carcinomas, yet little is known about the prognosis of glutathione peroxidase 2 in hepatocellular carcinoma. Glutathione peroxidase 2 expression was assessed by immunohistochemistry in hepatocellular carcinoma tissues. The association between glutathione peroxidase 2 expression with clinicopathological/prognostic value was examined. Glutathione peroxidase 2 overexpression was correlated with alpha-fetoprotein level, larger tumor, BCLC stage, and tumor recurrence. Kaplan-Meier analysis showed that glutathione peroxidase 2 was an independent predictor for overall survival and time to recurrence. glutathione peroxidase 2 overexpression was correlated with poor prognosis in patient subgroups stratified by tumor size, differentiation, tumor-node-metastasis, and BCLC stage. Moreover, stratified analysis showed that tumor-node-metastasis stage-I patients with high glutathione peroxidase 2 expression had poor prognosis than those with low glutathione peroxidase 2 expression. Additionally, combination of glutathione peroxidase 2 and serum alpha-fetoprotein was correlated with prognosis in hepatocellular carcinoma. In conclusion, glutathione peroxidase 2 overexpression contributes to poor prognosis of hepatocellular carcinoma patients and helps to identify the high-risk hepatocellular carcinoma patients.

PAQR3 Inhibits the Proliferation and Tumorigenesis in Esophageal Cancer Cells.

PubMed

Zhou, Fang; Wang, Shunchang; Wang, Jianjun

2017-05-24

Progestin and adipoQ receptor family member III (PAQR3), a member of the PAQR family, is frequently downregulated in different types of human cancer. However, its expression and functions in esophageal cancer are still unknown. This study aimed to explore the expression of PAQR3 in esophageal cancer cell lines and to investigate the role of PAQR3 in the development of esophageal cancer. Our data showed that PAQR3 is expressed in low amounts in human esophageal cancer cell lines. Overexpression of PAQR3 significantly suppressed the proliferation, migration, and invasion of esophageal cancer cells. In addition, overexpression of PAQR3 downregulated the protein expression levels of RAF1, p-MEK1, and p-ERK1/2 in esophageal cancer cells. Furthermore, overexpression of PAQR3 attenuated the tumor growth in a tumor xenograft model. In conclusion, we demonstrated that overexpression of PAQR3 suppresses cell proliferation, migration, and invasion in esophageal cancer in vitro and in vivo. Therefore, PAQR3 may act as a therapeutic target for human esophageal cancer.

Overexpression of the cucumber LEAFY homolog CFL and hormone treatments alter flower development in gloxinia (Sinningia speciosa).

PubMed

Zhang, Ming-Zhe; Ye, Dan; Wang, Li-Lin; Pang, Ji-Liang; Zhang, Yu-Hong; Zheng, Ke; Bian, Hong-Wu; Han, Ning; Pan, Jian-Wei; Wang, Jun-Hui; Zhu, Mu-Yuan

2008-07-01

Leafy (LFY) and LFY-like genes control the initiation of floral meristems and regulate MADS-box genes in higher plants. The Cucumber-FLO-LFY (CFL) gene, a LFY homolog in Cucumis sativus L. is expressed in the primordia, floral primordia, and each whirl of floral organs during the early stage of flower development. In this study, functions of CFL in flower development were investigated by overexpressing the CFL gene in gloxinia (Sinningia speciosa). Our results show that constitutive CFL overexpression significantly promote early flowering without gibberellin (GA(3)) supplement, suggesting that CFL can serve functionally as a LFY homolog in gloxinia. Moreover, GA(3) and abscisic acid (ABA) treatments could modulate the expression of MADS-box genes in opposite directions. GA(3) resembles the overexpression of CFL in the expression of MADS-box genes and the regeneration of floral buds, but ABA inhibits the expression of MADS-box genes and flower development. These results suggest that CFL and downstream MADS-box genes involved in flower development are regulated by GA(3) and ABA.

A Novel Role of Proline Oxidase in HIV-1 Envelope Glycoprotein-induced Neuronal Autophagy*

PubMed Central

Pandhare, Jui; Dash, Sabyasachi; Jones, Bobby; Villalta, Fernando; Dash, Chandravanu

2015-01-01

Proline oxidase (POX) catalytically converts proline to pyrroline-5-carboxylate. This catabolic conversion generates reactive oxygen species (ROS) that triggers cellular signaling cascades including autophagy and apoptosis. This study for the first time demonstrates a role of POX in HIV-1 envelope glycoprotein (gp120)-induced neuronal autophagy. HIV-1 gp120 is a neurotoxic factor and is involved in HIV-1-associated neurological disorders. However, the mechanism of gp120-mediated neurotoxicity remains unclear. Using SH-SY5Y neuroblastoma cells as a model, this study demonstrates that gp120 treatment induced POX expression and catalytic activity. Concurrently, gp120 also increased intracellular ROS levels. However, increased ROS had a minimal effect on neuronal apoptosis. Further investigation indicated that the immediate cellular response to increased ROS paralleled with induction of autophagy markers, beclin-1 and LC3-II. These data lead to the hypothesis that neuronal autophagy is activated as a cellular protective response to the toxic effects of gp120. A direct and functional role of POX in gp120-mediated neuronal autophagy was examined by inhibition and overexpression studies. Inhibition of POX activity by a competitive inhibitor “dehydroproline” decreased ROS levels concomitant with reduced neuronal autophagy. Conversely, overexpression of POX in neuronal cells increased ROS levels and activated ROS-dependent autophagy. Mechanistic studies suggest that gp120 induces POX by targeting p53. Luciferase reporter assays confirm that p53 drives POX transcription. Furthermore, data demonstrate that gp120 induces p53 via binding to the CXCR4 co-receptor. Collectively, these results demonstrate a novel role of POX as a stress response metabolic regulator in HIV-1 gp120-associated neuronal autophagy. PMID:26330555

The use of a viral 2A sequence for the simultaneous over-expression of both the vgf gene and enhanced green fluorescent protein (eGFP) in vitro and in vivo.

PubMed

Lewis, Jo E; Brameld, John M; Hill, Phil; Barrett, Perry; Ebling, Francis J P; Jethwa, Preeti H

2015-12-30

The viral 2A sequence has become an attractive alternative to the traditional internal ribosomal entry site (IRES) for simultaneous over-expression of two genes and in combination with recombinant adeno-associated viruses (rAAV) has been used to manipulate gene expression in vitro. To develop a rAAV construct in combination with the viral 2A sequence to allow long-term over-expression of the vgf gene and fluorescent marker gene for tracking of the transfected neurones in vivo. Transient transfection of the AAV plasmid containing the vgf gene, viral 2A sequence and eGFP into SH-SY5Y cells resulted in eGFP fluorescence comparable to a commercially available reporter construct. This increase in fluorescent cells was accompanied by an increase in VGF mRNA expression. Infusion of the rAAV vector containing the vgf gene, viral 2A sequence and eGFP resulted in eGFP fluorescence in the hypothalamus of both mice and Siberian hamsters, 32 weeks post infusion. In situ hybridisation confirmed that the location of VGF mRNA expression in the hypothalamus corresponded to the eGFP pattern of fluorescence. The viral 2A sequence is much smaller than the traditional IRES and therefore allowed over-expression of the vgf gene with fluorescent tracking without compromising viral capacity. The use of the viral 2A sequence in the AAV plasmid allowed the simultaneous expression of both genes in vitro. When used in combination with rAAV it resulted in long-term over-expression of both genes at equivalent locations in the hypothalamus of both Siberian hamsters and mice, without any adverse effects. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

High-Level Production of the Low-Calorie Sugar Sorbitol by Lactobacillus plantarum through Metabolic Engineering▿

PubMed Central

Ladero, Victor; Ramos, Ana; Wiersma, Anne; Goffin, Philippe; Schanck, André; Kleerebezem, Michiel; Hugenholtz, Jeroen; Smid, Eddy J.; Hols, Pascal

2007-01-01

Sorbitol is a low-calorie sugar alcohol that is largely used as an ingredient in the food industry, based on its sweetness and its high solubility. Here, we investigated the capacity of Lactobacillus plantarum, a lactic acid bacterium found in many fermented food products and in the gastrointestinal tract of mammals, to produce sorbitol from fructose-6-phosphate by reverting the sorbitol catabolic pathway in a mutant strain deficient for both l- and d-lactate dehydrogenase activities. The two sorbitol-6-phosphate dehydrogenase (Stl6PDH) genes (srlD1 and srlD2) identified in the genome sequence were constitutively expressed at a high level in this mutant strain. Both Stl6PDH enzymes were shown to be active, and high specific activity could be detected in the overexpressing strains. Using resting cells under pH control with glucose as a substrate, both Stl6PDHs were capable of rerouting the glycolytic flux from fructose-6-phosphate toward sorbitol production with a remarkably high efficiency (61 to 65% glucose conversion), which is close to the maximal theoretical value of 67%. Mannitol production was also detected, albeit at a lower level than the control strain (9 to 13% glucose conversion), indicating competition for fructose-6-phosphate rerouting by natively expressed mannitol-1-phosphate dehydrogenase. By analogy, low levels of this enzyme were detected in both the wild-type and the lactate dehydrogenase-deficient strain backgrounds. After optimization, 25% of sugar conversion into sorbitol was achieved with cells grown under pH control. The role of intracellular NADH pools in the determination of the maximal sorbitol production is discussed. PMID:17261519

RHOMBOID DOMAIN CONTAINING 2 (RHBDD2)

PubMed Central

Abba, MC; Lacunza, E; Nunez, MI; Colussi, A; Isla-Larrain, M; Segal-Eiras, A; Croce, MV; Aldaz, CM

2009-01-01

In the course of breast cancer global gene expression studies, we identified an uncharacterized gene known as RHBDD2 (Rhomboid domain containing 2) to be markedly over-expressed in primary tumors from patients with recurrent disease. In this study, we identified RHBDD2 mRNA and protein expression significantly elevated in breast carcinomas compared with normal breast samples as analyzed by SAGE (n=46) and immunohistochemistry (n=213). Interestingly, specimens displaying RHBDD2 over-expression were predominantly advanced stage III breast carcinomas (p=0.001). Western-blot, RT-PCR and cDNA sequencing analyses allowed us to identify two RHBDD2 alternatively spliced mRNA isoforms expressed in breast cancer cell lines. We further investigated the occurrence and frequency of gene amplification and over-expression affecting RHBDD2 in 131 breast samples. RHBDD2 gene amplification was detected in 21% of 98 invasive breast carcinomas analyzed. However, no RHBDD2 amplification was detected in normal breast tissues (n=17) or breast benign lesions (n=16) (p=0.014). Interestingly, siRNA mediated silencing of RHBDD2 expression results in a decrease of MCF7 breast cancer cells proliferation compared with the corresponding controls (p=0.001). In addition, analysis of publicly available gene expression data showed a strong association between high RHBDD2 expression and decreased overall survival (p=0.0023), relapse-free survival (p= 0.0013), and metastasis-free interval (p=0.006) in patients with primary ER-negative breast carcinomas. In conclusion, our findings suggest that RHBDD2 over-expression behaves as an indicator of poor prognosis and may play a role facilitating breast cancer progression. PMID:19616622

Escitalopram alters gene expression and HPA axis reactivity in rats following chronic overexpression of corticotropin-releasing factor from the central amygdala

PubMed Central

Flandreau, Elizabeth I.; Bourke, Chase H.; Ressler, Kerry J.; Vale, Wylie W.; Nemeroff, Charles B.; Owens, Michael J.

2013-01-01

Summary We have previously demonstrated that viral-mediated overexpression of corticotropin-releasing factor (CRF) within the central nucleus of the amygdala (CeA) reproduces many of the behavioral and endocrine consequences of chronic stress. The present experiment sought to determine whether administration of the selective serotonin reuptake inhibitor (SSRI) escitalopram reverses the adverse effects of CeA CRF overexpression. In a 2 × 2 design, adult male rats received bilateral infusions of a control lentivirus or a lentivirus in which a portion of the CRF promoter is used to drive increased expression of CRF peptide. Four weeks later, rats were then implanted with an Alzet minipump to deliver vehicle or 10 mg/kg/day escitalopram for a 4-week period of time. The defensive withdrawal (DW) test of anxiety and the sucrose-preference test (SPT) of anhedonia were performed both before and after pump implantation. Additional post-implant behavioral tests included the elevated plus maze (EPM) and social interaction (SI) test. Following completion of behavioral testing, the dexamethasone/CRF test was performed to assess HPA axis reactivity. Brains were collected and expression of HPA axis-relevant transcripts were measured using in situ hybridization. Amygdalar CRF overexpression increased anxiety-like behavior in the DW test at week eight, which was only partially prevented by escitalopram. In both CRF-overexpressing and control groups, escitalopram decreased hippocampal CRF expression while increasing hypothalamic and hippocampal expression of the glucocorticoid receptor (GR). These gene expression changes were associated with a significant decrease in HPA axis reactivity in rats treated with escitalopram. Interestingly, escitalopram increased the rate of weight gain only in rats overexpressing CRF. Overall these data support our hypothesis that amygdalar CRF is critical in anxiety-like behavior; because the antidepressant was unable to reverse behavioral manifestations of CeA CRF-OE. This may be a potential animal model to study treatment-resistant psychopathologies. PMID:23267723

First somatic mutation of E2F1 in a critical DNA binding residue discovered in well-differentiated papillary mesothelioma of the peritoneum

PubMed Central

2011-01-01

Background Well differentiated papillary mesothelioma of the peritoneum (WDPMP) is a rare variant of epithelial mesothelioma of low malignancy potential, usually found in women with no history of asbestos exposure. In this study, we perform the first exome sequencing of WDPMP. Results WDPMP exome sequencing reveals the first somatic mutation of E2F1, R166H, to be identified in human cancer. The location is in the evolutionarily conserved DNA binding domain and computationally predicted to be mutated in the critical contact point between E2F1 and its DNA target. We show that the R166H mutation abrogates E2F1's DNA binding ability and is associated with reduced activation of E2F1 downstream target genes. Mutant E2F1 proteins are also observed in higher quantities when compared with wild-type E2F1 protein levels and the mutant protein's resistance to degradation was found to be the cause of its accumulation within mutant over-expressing cells. Cells over-expressing wild-type E2F1 show decreased proliferation compared to mutant over-expressing cells, but cell proliferation rates of mutant over-expressing cells were comparable to cells over-expressing the empty vector. Conclusions The R166H mutation in E2F1 is shown to have a deleterious effect on its DNA binding ability as well as increasing its stability and subsequent accumulation in R166H mutant cells. Based on the results, two compatible theories can be formed: R166H mutation appears to allow for protein over-expression while minimizing the apoptotic consequence and the R166H mutation may behave similarly to SV40 large T antigen, inhibiting tumor suppressive functions of retinoblastoma protein 1. PMID:21955916

Periostin in Mature Stage Localized Scleroderma.

PubMed

Kim, Min-Woo; Park, Jung Tae; Kim, Jung Ho; Koh, Seong-Joon; Yoon, Hyun-Sun; Cho, Soyun; Park, Hyun-Sun

2017-06-01

Periostin is a novel matricellular protein expressed in many tissues, including bone, periodontal ligament, and skin. Although its expression is prominent in various fibrotic conditions, studies of periostin in localized scleroderma are rare. To investigate the expression of periostin and other molecules in localized scleroderma. A retrospective study of 14 patients with confirmed mature stage localized scleroderma was undertaken. Fourteen age-matched and biopsy site-matched subjects with normal skin were included as controls. Collagen fiber deposition, periostin, procollagen, transforming growth factor-β, and matrix metalloproteinase (MMP)-1 expression were assessed and compared between the two groups. Co-localization of α-smooth muscle actin and periostin was evaluated using confocal microscopy. Periostin was predominantly expressed along the dermo-epidermal junction in the controls. Conversely, patients with localized scleroderma demonstrated increased collagen fiber deposition and periostin expression that was more widely distributed along the entire dermis. MMP-1 staining showed increased expression in the epidermis and dermis of patients compared to scanty expression in the controls. A semi-quantitative evaluation showed a higher proportion of excessive collagen bundle deposition (57.1% vs. 7.1%, p =0.013), diffuse periostin positivity (42.9% vs. 0%, p =0.016), and moderate MMP-1 positivity (71.4% vs. 7.1%, p =0.001) in patients than in the controls. Compared to the controls, patients with localized scleroderma had enhanced periostin expression corresponding to increased collagen fiber deposition and unexpected overexpression of MMP-1. The results of this human in vivo study may implicate the pathogenesis of localized scleroderma.

Overexpression of SLC34A2 is an independent prognostic indicator in bladder cancer and its depletion suppresses tumor growth via decreasing c-Myc expression and transcriptional activity

PubMed Central

Ye, Wen; Chen, Cui; Gao, Ying; Zheng, Zou-Shan; Xu, Yi; Yun, Miao; Weng, Hui-Wen; Xie, Dan; Ye, Sheng; Zhang, Jia-Xing

2017-01-01

Solute carrier family 34 member 2 (SLC34A2), a pH-sensitive sodium-dependent phosphate transporter, is associated with several human cancers. In this study, we investigate the clinical significance of SLC34A2 and its function in human bladder cancer (BC). The expression dynamics of SLC34A2 were examined in two independent cohorts of BC samples by quantitative PCR, western blotting and immunohistochemical staining. In the training cohort (156 cases), we applied the X-tile program software to assess the optimal cutoff points for biomarkers in order to accurately classify patients according to clinical outcome. In the validation cohort (130 cases), the cutoff score derived from X-title analysis was investigated to determine the association of SLC34A2 expression with survival outcome. A series of in vitro and in vivo assays were then performed to elucidate the function of SLC34A2 in BC and its underlying mechanisms. Results showed that SLC34A2 was significantly upregulated in BC cell lines and clinical samples. In both two cohorts of BC samples, high expression of SLC34A2 was associated with large tumor size, advanced T status and poor patients' survival. The depletion of SLC34A2 in BC suppressed cellular viability, colony formation and anchorage-independent growth in vitro, and inhibited xenograft tumor growth in vivo, whereas overexpression of SLC34A2 had the converse effect. Simultaneously, downregulation of SLC34A2 decreased the transcriptional activity and protein expression level of c-Myc in BC cells, whereas restoration of c-Myc expression could compromise the anti-proliferation effect of SLC34A2 depletion. Furthermore, miR-214 was proved as a negative regulator of SLC34A2. Our present study illustrated that SLC34A2 has an important role in promoting proliferation and tumorigenicity of BC, and may represent a novel therapeutic target for this disease. PMID:28151475

The long non-coding RNA PTTG3P promotes cell growth and metastasis via up-regulating PTTG1 and activating PI3K/AKT signaling in hepatocellular carcinoma.

PubMed

Huang, Jin-Lan; Cao, Shun-Wang; Ou, Qi-Shui; Yang, Bin; Zheng, Shi-Hao; Tang, Jing; Chen, Jing; Hu, Yan-Wei; Zheng, Lei; Wang, Qian

2018-05-26

Dysfunctions of long non-coding RNA (lncRNAs) have been associated with the initiation and progression of hepatocellular carcinoma (HCC), but the clinicopathologic significance and potential role of lncRNA PTTG3P (pituitary tumor-transforming 3, pseudogene) in HCC remains largely unknown. We compared the expression profiles of lncRNAs in 3 HCC tumor tissues and adjacent non-tumor tissues by microarrays. In situ hybridization (ISH) and quantitative real-time polymerase chain reaction (qRT-PCR) were applied to assess the level of PTTG3P and prognostic values of PTTG3P were assayed in two HCC cohorts (n = 46 and 90). Artificial modulation of PTTG3P (down- and over-expression) was performed to explore the role of PTTG3P in tumor growth and metastasis in vitro and in vivo. Involvement of PTTG1 (pituitary tumor-transforming 1), PI3K/AKT signaling and its downstream signals were validated by qRT-PCR and western blot. We found that PTTG3P was frequently up-regulated in HCC and its level was positively correlated to tumor size, TNM stage and poor survival of patients with HCC. Enforced expression of PTTG3P significantly promoted cell proliferation, migration, and invasion in vitro, as well as tumorigenesis and metastasis in vivo. Conversely, PTTG3P knockdown had opposite effects. Mechanistically, over-expression of PTTG3P up-regulated PTTG1, activated PI3K/AKT signaling and its downstream signals including cell cycle progression, cell apoptosis and epithelial-mesenchymal transition (EMT)-associated genes. Our findings suggest that PTTG3P, a valuable marker of HCC prognosis, promotes tumor growth and metastasis via up-regulating PTTG1 and activating PI3K/AKT signaling in HCC and might represent a potential target for gene-based therapy.

CD90/THY1 is over-expressed in prostate cancer-associated fibroblasts and could serve as a cancer biomarker

PubMed Central

True, Lawrence D; Zhang, Hui; Ye, Mingliang; Huang, Chung-Ying; Nelson, Peter S; von Haller, Priska D; Tjoelker, Larry W; Kim, Jong-Seo; Qian, Wei-Jun; Smith, Richard D; Ellis, William J; Liebeskind, Emily S; Liu, Alvin Y

2010-01-01

A by-product in the processing of prostate tissue for cell sorting by collagenase digestion is the media supernatant that remains after the cells are harvested. These supernatants contain proteins made by the cells within the tissue. Quantitative proteomic analysis of N-glycosylated proteins detected an increased amount of CD90/THY1 in cancer supernatants compared to non-cancer supernatants. Immunohistochemistry showed that in all carcinomas, regardless of Gleason grade, a layer of CD90-positive stromal fibroblastic cells, approximately 5-to-10 cells deep, was localized to tumor glands. In contrast, a no more than 1-cell wide girth of CD90-positive stromal cells was found around benign glands. The increased number of CD90-positive stromal cells in cancer correlated with overexpression of CD90 mRNA detected by gene expression analysis of stromal cells obtained by laser-capture microdissection. There is increasing evidence that cancer-associated stroma plays a role in both tumor progression and carcinogenesis. Most experiments to identify cancer biomarkers have focused on the cancer cells. CD90, being a marker for prostate cancer-associated stroma, might be a potential biomarker for this cancer. A non-invasive test could be provided by a urine test. Proteomic analysis of urine from patients with prostate cancer identified CD90; conversely, CD90 was not detected in the urine of post-prostatectomy patients. Furthermore, this urinary CD90 protein was a variant CD90 protein not known to be expressed by such cells as lymphocytes that express CD90. These CD90 results were obtained from ∼90 cases consisting of proteomic analysis of tissue and urine, immunohistochemistry, Western blot analysis of tissue media, flow cytometry of cells from digested tissue, and reverse transcriptase polymerase chain reaction analysis of isolated stromal cells. PMID:20562849

Epigenetic suppression of neprilysin regulates breast cancer invasion

PubMed Central

Stephen, H M; Khoury, R J; Majmudar, P R; Blaylock, T; Hawkins, K; Salama, M S; Scott, M D; Cosminsky, B; Utreja, N K; Britt, J; Conway, R E

2016-01-01

In women, invasive breast cancer is the second most common cancer and the second cause of cancer-related death. Therefore, identifying novel regulators of breast cancer invasion could lead to additional biomarkers and therapeutic targets. Neprilysin, a cell-surface enzyme that cleaves and inactivates a number of substrates including endothelin-1 (ET1), has been implicated in breast cancer, but whether neprilysin promotes or inhibits breast cancer cell progression and metastasis is unclear. Here, we asked whether neprilysin expression predicts and functionally regulates breast cancer cell invasion. RT–PCR and flow cytometry analysis of MDA-MB-231 and MCF-7 breast cancer cell lines revealed decreased neprilysin expression compared with normal epithelial cells. Expression was also suppressed in invasive ductal carcinoma (IDC) compared with normal tissue. In addition, in vtro invasion assays demonstrated that neprilysin overexpression decreased breast cancer cell invasion, whereas neprilysin suppression augmented invasion. Furthermore, inhibiting neprilysin in MCF-7 breast cancer cells increased ET1 levels significantly, whereas overexpressing neprilysin decreased extracellular-signal related kinase (ERK) activation, indicating that neprilysin negatively regulates ET1-induced activation of mitogen-activated protein kinase (MAPK) signaling. To determine whether neprilysin was epigenetically suppressed in breast cancer, we performed bisulfite conversion analysis of breast cancer cells and clinical tumor samples. We found that the neprilysin promoter was hypermethylated in breast cancer; chemical reversal of methylation in MDA-MB-231 cells reactivated neprilysin expression and inhibited cancer cell invasion. Analysis of cancer databases revealed that neprilysin methylation significantly associates with survival in stage I IDC and estrogen receptor-negative breast cancer subtypes. These results demonstrate that neprilysin negatively regulates the ET axis in breast cancer, and epigenetic suppression of neprilysin in invasive breast cancer cells enables invasion. Together, this implicates neprilysin as an important regulator of breast cancer invasion and clarifies its utility as a potential biomarker for invasive breast cancer. PMID:26950599

Epigenetic suppression of neprilysin regulates breast cancer invasion.

PubMed

Stephen, H M; Khoury, R J; Majmudar, P R; Blaylock, T; Hawkins, K; Salama, M S; Scott, M D; Cosminsky, B; Utreja, N K; Britt, J; Conway, R E

2016-03-07

In women, invasive breast cancer is the second most common cancer and the second cause of cancer-related death. Therefore, identifying novel regulators of breast cancer invasion could lead to additional biomarkers and therapeutic targets. Neprilysin, a cell-surface enzyme that cleaves and inactivates a number of substrates including endothelin-1 (ET1), has been implicated in breast cancer, but whether neprilysin promotes or inhibits breast cancer cell progression and metastasis is unclear. Here, we asked whether neprilysin expression predicts and functionally regulates breast cancer cell invasion. RT-PCR and flow cytometry analysis of MDA-MB-231 and MCF-7 breast cancer cell lines revealed decreased neprilysin expression compared with normal epithelial cells. Expression was also suppressed in invasive ductal carcinoma (IDC) compared with normal tissue. In addition, in vtro invasion assays demonstrated that neprilysin overexpression decreased breast cancer cell invasion, whereas neprilysin suppression augmented invasion. Furthermore, inhibiting neprilysin in MCF-7 breast cancer cells increased ET1 levels significantly, whereas overexpressing neprilysin decreased extracellular-signal related kinase (ERK) activation, indicating that neprilysin negatively regulates ET1-induced activation of mitogen-activated protein kinase (MAPK) signaling. To determine whether neprilysin was epigenetically suppressed in breast cancer, we performed bisulfite conversion analysis of breast cancer cells and clinical tumor samples. We found that the neprilysin promoter was hypermethylated in breast cancer; chemical reversal of methylation in MDA-MB-231 cells reactivated neprilysin expression and inhibited cancer cell invasion. Analysis of cancer databases revealed that neprilysin methylation significantly associates with survival in stage I IDC and estrogen receptor-negative breast cancer subtypes. These results demonstrate that neprilysin negatively regulates the ET axis in breast cancer, and epigenetic suppression of neprilysin in invasive breast cancer cells enables invasion. Together, this implicates neprilysin as an important regulator of breast cancer invasion and clarifies its utility as a potential biomarker for invasive breast cancer.

Aurora-A overexpression and aneuploidy predict poor outcome in serous ovarian carcinoma.

PubMed

Lassus, Heini; Staff, Synnöve; Leminen, Arto; Isola, Jorma; Butzow, Ralf

2011-01-01

Aurora-A is a potential oncogene and therapeutic target in ovarian carcinoma. It is involved in mitotic events and overexpression leads to centrosome amplification and chromosomal instability. The objective of this study was to evaluate the clinical significance of Aurora-A and DNA ploidy in serous ovarian carcinoma. Serous ovarian carcinomas were analysed for Aurora-A protein by immunohistochemistry (n=592), Aurora-A copy number by CISH (n=169), Aurora-A mRNA by real-time PCR (n=158) and DNA ploidy by flowcytometry (n=440). Overexpression of Aurora-A was found in 27% of the tumors, cytoplasmic overexpression in 11% and nuclear in 17%. The cytoplasmic and nuclear overexpression were nearly mutually exclusive. Both cytoplasmic and nuclear overexpression were associated with shorter survival, high grade, high proliferation index and aberrant p53. Interestingly, only cytoplasmic expression was associated with aneuploidy and expression of phosphorylated Aurora-A. DNA ploidy was associated with poor patient outcome as well as aggressive clinicopathological parameters. In multivariate analysis, Aurora-A overexpression appeared as an independent prognostic factor for disease-free survival, together with grade, stage and ploidy. Aurora-A protein expression is strongly linked with poor patient outcome and aggressive disease characteristics, which makes Aurora-A a promising biomarker and a potential therapeutic target in ovarian carcinoma. Cytoplasmic and nuclear Aurora-A protein may have different functions. DNA aneuploidy is a strong predictor of poor prognosis in serous ovarian carcinoma. Copyright © 2010 Elsevier Inc. All rights reserved.

Over-expression of Trxo1 increases the viability of tobacco BY-2 cells under H2O2 treatment

PubMed Central

Ortiz-Espín, Ana; Locato, Vittoria; Camejo, Daymi; Schiermeyer, Andreas; De Gara, Laura; Sevilla, Francisca; Jiménez, Ana

2015-01-01

Background and Aims Reactive oxygen species (ROS), especially hydrogen peroxide, play a critical role in the regulation of plant development and in the induction of plant defence responses during stress adaptation, as well as in plant cell death. The antioxidant system is responsible for controlling ROS levels in these processes but redox homeostasis is also a key factor in plant cell metabolism under normal and stress situations. Thioredoxins (Trxs) are ubiquitous small proteins found in different cell compartments, including mitochondria and nuclei (Trxo1), and are involved in the regulation of target proteins through reduction of disulphide bonds, although their role under oxidative stress has been less well studied. This study describes over-expression of a Trxo1 for the first time, using a cell-culture model subjected to an oxidative treatment provoked by H2O2. Methods Control and over-expressing PsTrxo1 tobacco (Nicotiana tabacum) BY-2 cells were treated with 35 mm H2O2 and the effects were analysed by studying the growth dynamics of the cultures together with oxidative stress parameters, as well as several components of the antioxidant systems involved in the metabolism of H2O2. Analysis of different hallmarks of programmed cell death was also carried out. Key Results Over-expression of PsTrxo1 caused significant differences in the response of TBY-2 cells to high concentrations of H2O2, namely higher and maintained viability in over-expressing cells, whilst the control line presented a severe decrease in viability and marked indications of oxidative stress, with generalized cell death after 3 d of treatment. In over-expressing cells, an increase in catalase activity, decreases in H2O2 and nitric oxide contents and maintenance of the glutathione redox state were observed. Conclusions A decreased content of endogenous H2O2 may be responsible in part for the delayed cell death found in over-expressing cells, in which changes in oxidative parameters and antioxidants were less extended after the oxidative treatment. It is concluded that PsTrxo1 transformation protects TBY-2 cells from exogenous H2O2, thus increasing their viability via a process in which not only antioxidants but also Trxo1 seem to be involved. PMID:26041732

Overexpression of HSPA1A enhances the osteogenic differentiation of bone marrow mesenchymal stem cells via activation of the Wnt/β-catenin signaling pathway

PubMed Central

Zhang, Wei; Xue, Deting; Yin, Houfa; Wang, Shengdong; Li, Chao; Chen, Erman; Hu, Dongcai; Tao, Yiqing; Yu, Jiawei; Zheng, Qiang; Gao, Xiang; Pan, Zhijun

2016-01-01

HSPA1A, which encodes cognate heat shock protein 70, plays important roles in various cellular metabolic pathways. To investigate its effects on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), its expression level was compared between undifferentiated and differentiated BMSCs. Rat HSPA1A overexpression in BMSCs increased osteoblast-specific gene expression, alkaline phosphatase activity, and mineral deposition in vitro. Moreover, it upregulated β-catenin and downregulated DKK1 and SOST. The enhanced osteogenesis due to HSPA1A overexpression was partly rescued by a Wnt/β-catenin inhibitor. Additionally, using a rat tibial fracture model, a sheet of HSPA1A-overexpressing BMSCs improved bone fracture healing, as determined by imaging and histological analysis. Taken together, these findings suggest that HSPA1A overexpression enhances osteogenic differentiation of BMSCs, partly through Wnt/β-catenin. PMID:27279016

MTA1 regulation of ERβ pathway in salivary gland carcinoma cells

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

Ohshiro, Kazufumi, E-mail: bcmkxo@gwu.edu; Kumar, Rakesh

Abstracts: Although Metastatic-tumor antigen 1 (MTA1) is differentially expressed in metastatic cancer and coregulates the status and activity of nuclear receptors, its role upon estrogen receptor β (ERβ) – a potent tumor suppressor, remains poorly understood. Here we investigated whether MTA1 regulates the expression and functions of ERβ, an ER isoform predominantly expressed in salivary gland cancer cells. We found that the depletion of the endogenous MTA1 in the HSG and HSY salivary duct carcinoma cell lines enhances the expression of ERβ while MTA1 overexpression augmented the expression of ERβ in salivary duct carcinoma cells. Furthermore, MTA1 knockdown inhibited themore » proliferations and invasion of HSG and HSY cells. The noted ERβ downregulation by MTA1 overexpression involves the process of proteasomal degradation, as a proteasome inhibitor could block it. In addition, both MTA1 knockdown and ERβ overexpression attenuated the cell migration and inhibited the ERK1/2 signaling in the both cell lines. These findings imply that MTA1 dysregulation in a subset of salivary gland cancer might promote aggressive phenotypes by compromising the tumor suppressor activity of ERβ, and hence, MTA1-ERβ axis might serve a new therapeutic target for the salivary gland cancer. - Highlights: • MTA1 silencing upregulates ERβ expression in salivary gland carcinoma cells. • MTA1 overexpression downregulates ERβ expression via proteasomal degradation. • Upregulation of ERβ expression inhibits cell migration and ERK signaling. • MTA1 knockdown inhibits cell proliferation and invasion.« less

Overexpression of Indian hedgehog partially rescues short stature homeobox 2-overexpression-associated congenital dysplasia of the temporomandibular joint in mice

PubMed Central

LI, XIHAI; LIANG, WENNA; YE, HONGZHI; WENG, XIAPING; LIU, FAYUAN; LIN, PINGDONG; LIU, XIANXIANG

2015-01-01

The role of short stature homeobox 2 (shox2) in the development and homeostasis of the temporomandibular joint (TMJ) has been well documented. Shox2 is known to be expressed in the progenitor cells and perichondrium of the developing condyle. A previous study by our group reported that overexpression of shox2 leads to congenital dysplasia of the TMJ via downregulation of the Indian hedgehog (Ihh) signaling pathway, which is essential for embryonic disc primordium formation and mandibular condylar growth. To determine whether overexpression of Ihh may rescue the overexpression of shox2 leading to congenital dysplasia of the TMJ, a mouse model in which Ihh and shox2 were overexpressed (Wnt1-Cre; pMes-stop shox2; pMes-stop Ihh mice) was utilized to assess the consequences of this overexpression on TMJ development during post-natal life. The results showed that the developmental process and expression levels of runt-related transcription factor 2 and sex determining region Y-box 9 in the TMJ of the Wnt1-Cre; pMes-stop shox2; pMes-stop Ihh mice were similar to those in wild-type mice. Overexpression of Ihh rescued shox2 overexpression-associated reduction of extracellular matrix components. However, overexpression of Ihh did not inhibit the shox2 overexpression-associated increase of matrix metalloproteinases (MMPs) MMP9, MMP13 and apoptosis in the TMJ. These combinatory cellular and molecular defects appeared to account for the observed congenital dysplasia of TMJ, suggesting that overexpression of Ihh partially rescued shox2 overexpression-associated congenital dysplasia of the TMJ in mice. PMID:26096903

Breast cancer stem cells in HER2-negative breast cancer cells contribute to HER2-mediated radioresistance and molecular subtype conversion: clinical implications for serum HER2 in recurrent HER2-negative breast cancer.

PubMed

Kim, Yun Gyoung; Yoon, Yi Na; Choi, Hyang Suk; Kim, Ji-Hyun; Seol, Hyesil; Lee, Jin Kyung; Seong, Min-Ki; Park, In Chul; Kim, Kwang Il; Kim, Hyun-Ah; Kim, Jae-Sung; Noh, Woo Chul

2018-01-19

Although it has been proposed that the beneficial effect of HER2-targeted therapy in HER2-negative breast cancer is associated with the molecular subtype conversion, the underlying mechanism and the clinical biomarkers are unclear. Our study showed that breast cancer stem cells (BCSCs) mediated HER2 subtype conversion and radioresistance in HER2-negative breast cancer cells and evaluated serum HER2 as a clinical biomarker for HER2 subtype conversion. We found that the CD44 + /CD24 -/low BCSCs from HER2-negative breast cancer MCF7 cells overexpressed HER2 and EGFR and showed the radioresistant phenotype. In addition, we showed that trastuzumab treatment sensitized the radioresistant phenotype of the CD44 + /CD24 -/low cells with decreased levels of HER2 and EGFR, which suggested that HER2-targeted therapy in HER2-negative breast cancer could be useful for targeting BCSCs that overexpress HER2/EGFR. Importantly, our clinical data showed that serial serum HER2 measurement synchronously reflected the disease relapse and the change in tumor burden in some patients who were initially diagnosed as HER2-negative breast cancer, which indicated that serum HER2 could be a clinical biomarker for the evaluation of HER2 subtype conversion in patients with recurrent HER2-negative breast cancer. Therefore, our data have provided in vitro and in vivo evidence for the molecular subtype conversion of HER2-negative breast cancer.

Prader-Willi Syndrome: Intellectual Abilities and Behavioural Features by Genetic Subtype

ERIC Educational Resources Information Center

Milner, Katja M.; Craig, Ellen E.; Thompson, Russell J.; Veltman, Marijcke W. M.; Simon Thomas, N.; Roberts, Sian; Bellamy, Margaret; Curran, Sarah R.; Sporikou, Caroline M. J.; Bolton, Patrick F.

2005-01-01

Background: Studies of chromosome 15 abnormality have implicated over-expression of paternally imprinted genes in the 15q11-13 region in the aetiology of autism. To test this hypothesis we compared individuals with Prader-Willi syndrome (PWS) due to uniparental disomy (UPD--where paternally imprinted genes are over-expressed) to individuals with…

Six1 overexpression at early stages of HPV16-mediated transformation of human keratinocytes promotes differentiation resistance and EMT

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

Xu, Hanwen; Pirisi, Lucia; Creek, Kim E., E-mail: creekk@sccp.sc.edu

Previous studies in our laboratory discovered that SIX1 mRNA expression increased during in vitro progression of HPV16-immortalized human keratinocytes (HKc/HPV16) toward a differentiation-resistant (HKc/DR) phenotype. In this study, we explored the role of Six1 at early stages of HPV16-mediated transformation by overexpressing Six1 in HKc/HPV16. We found that Six1 overexpression in HKc/HPV16 increased cell proliferation and promoted cell migration and invasion by inducing epithelial–mesenchymal transition (EMT). Moreover, the overexpression of Six1 in HKc/HPV16 resulted in resistance to serum and calcium-induced differentiation, which is the hallmark of the HKc/DR phenotype. Activation of MAPK in HKc/HPV16 overexpressing Six1 is linked to resistancemore » to calcium-induced differentiation. In conclusion, this study determined that Six1 overexpression resulted in differentiation resistance and promoted EMT at early stages of HPV16-mediated transformation of human keratinocytes. - Highlights: • Six1 expression increases during HPV16-mediated transformation. • Six1 overexpression causes differentiation resistance in HPV16-immortalized cells. • Six1 overexpression in HPV16-immortalized keratinocytes activates MAPK. • Activation of MAPK promotes EMT and differentiation resistance. • Six1 overexpression reduces Smad-dependent TGF-β signaling.« less

Gastrin-releasing peptide-induced down-regulation of tumor suppressor protein PTEN (phosphatase and tensin homolog deleted on chromosome ten) in neuroblastomas.

PubMed

Qiao, Jingbo; Kang, Junghee; Cree, Jeremy; Evers, B Mark; Chung, Dai H

2005-05-01

To evaluate whether aggressive, undifferentiated neuroblastomas express tumor suppressor protein PTEN (phosphatase and tensin homolog deleted on chromosome ten) and to examine the effects of gastrin-releasing peptide (GRP) on PTEN gene and protein expression. We have previously shown that neuroblastomas secrete GRP, which binds to its cell surface receptor (GRP-R) to stimulate cell growth in an autocrine fashion. However, the effects of GRP on expression of the tumor suppressor gene PTEN have not been elucidated in neuroblastomas. Paraffin-embedded sections from human neuroblastomas were analyzed for PTEN and phospho-Akt protein expression by immunohistochemistry. Human neuroblastoma cell lines (SK-N-SH and SH-SY5Y) were stably transfected with the plasmid pEGFP-GRP-R to establish GRP-R overexpression cell lines, and the effects of GRP on PTEN gene and protein expression were determined. A decrease in the ratio of PTEN to phospho-Akt protein expression was identified in poorly differentiated neuroblastomas. An increase in GRP binding capacity was confirmed in GRP-R overexpressing cells, which demonstrated an accelerated constitutive cell growth rate. PTEN gene and protein expression was significantly decreased in GRP-R overexpressing cells when compared with controls. Our findings demonstrate decreased expression of the tumor suppressor protein PTEN in more aggressive undifferentiated neuroblastomas. An increase in GRP binding capacity, as a result of GRP-R overexpression, down-regulates PTEN expression. These findings suggest that an inhibition of the tumor suppressor gene PTEN may be an important regulatory mechanism involved in GRP-induced cell proliferation in neuroblastomas.

Accumulated Expression Level of Cytosolic Glutamine Synthetase 1 Gene (OsGS1;1 or OsGS1;2) Alter Plant Development and the Carbon-Nitrogen Metabolic Status in Rice

PubMed Central

Bao, Aili; Zhao, Zhuqing; Ding, Guangda; Shi, Lei; Xu, Fangsen; Cai, Hongmei

2014-01-01

Maintaining an appropriate balance of carbon to nitrogen metabolism is essential for rice growth and yield. Glutamine synthetase is a key enzyme for ammonium assimilation. In this study, we systematically analyzed the growth phenotype, carbon-nitrogen metabolic status and gene expression profiles in GS1;1-, GS1;2-overexpressing rice and wildtype plants. Our results revealed that the GS1;1-, GS1;2-overexpressing plants exhibited a poor plant growth phenotype and yield and decreased carbon/nitrogen ratio in the stem caused by the accumulation of nitrogen in the stem. In addition, the leaf SPAD value and photosynthetic parameters, soluble proteins and carbohydrates varied greatly in the GS1;1-, GS1;2-overexpressing plants. Furthermore, metabolite profile and gene expression analysis demonstrated significant changes in individual sugars, organic acids and free amino acids, and gene expression patterns in GS1;1-, GS1;2-overexpressing plants, which also indicated the distinct roles that these two GS1 genes played in rice nitrogen metabolism, particularly when sufficient nitrogen was applied in the environment. Thus, the unbalanced carbon-nitrogen metabolic status and poor ability of nitrogen transportation from stem to leaf in GS1;1-, GS1;2-overexpressing plants may explain the poor growth and yield. PMID:24743556

The relation between xyr1 overexpression in Trichoderma harzianum and sugarcane bagasse saccharification performance.

PubMed

da Silva Delabona, Priscila; Rodrigues, Gisele Nunes; Zubieta, Mariane Paludetti; Ramoni, Jonas; Codima, Carla Aloia; Lima, Deise Juliana; Farinas, Cristiane Sanchez; da Cruz Pradella, José Geraldo; Seiboth, Bernhard

2017-03-20

This work investigates the influence of the positive regulator XYR1 of Trichoderma harzianum on the production of cellulolytic enzymes, using sugarcane bagasse as carbon source. Constitutive expression of xyr1 was achieved under the control of the strong Trichoderma reesei pki1 promoter. Five clones with xyr1 overexpression achieved higher xyr1 expression and greater enzymatic productivity when cultivated under submerged fermentation, hence validating the genetic construction for T. harzianum. Clone 5 presented a relative expression of xyr1 26-fold higher than the parent strain and exhibited 66, 37, and 36% higher values for filter paper activity, xylanase activity, and β-glucosidase activity, respectively, during cultivation in a stirred-tank bioreactor. The overexpression of xyr1 in T. harzianum resulted in an enzymatic complex with significantly improved performance in sugarcane bagasse saccharification, with an enhancement of 25% in the first 24h. Our results also show that constitutive overexpression of xyr1 leads to the induction of several important players in biomass degradation at early (24h) and also late (48h) timepoints of inoculation. However, we also observed that the carbon catabolite repressor CRE1 was upregulated in xyr1 overexpression mutants. These findings demonstrate the feasibility of improving cellulase production by modifying regulator expression and suggest an attractive approach for increasing total cellulase productivity in T. harzianum. Copyright © 2017 Elsevier B.V. All rights reserved.

Increased expression of Nlp, a potential oncogene in ovarian cancer, and its implication in carcinogenesis.

PubMed

Qu, Danni; Qu, Hongyan; Fu, Ming; Zhao, Xuelian; Liu, Rong; Sui, Lihua; Zhan, Qimin

2008-08-01

Nlp (Ninein-like protein), a novel centrosome protein involved in microtubule nucleation, has been studied extensively in our laboratory, and its overexpression has been found in some human tumors. To understand the role of Nlp in human ovarian cancer development, we studied the correlation of Nlp expression with clinicopathological parameters and survival in epithelial ovarian cancer, and the impact of Nlp overexpression on ovarian cancer cells. Nlp expression in normal, borderline, benign and malignant epithelial ovarian tissues was examined by immunohistochemistry. The correlation between Nlp expression and tumor grade, FIGO stage and histological type was also evaluated. Survival was calculated using Kaplan-Meier estimates. Cell proliferation and apoptosis were assayed after stable transfection of pEGFP-C3-Nlp or empty vector in human ovarian cancer cell line SKOV3. Nlp was positive in 1 of 10 (10%) normal ovarian tissues, 5 of 34 (14.7%) benign tumors, 9 of 26 (34.6%) borderline tumors and 73 of 131 (56.0%) ovarian tumors. Nlp immunoreactivity intensity significantly correlated with tumor grade, but not with FIGO stage or histological type. Kaplan-Meier curves showed that Nlp overexpression was marginally associated with decreased overall survival. Overexpression of Nlp enhanced proliferation and inhibited apoptosis induced by paclitaxel in the SKOV3 cell line. Overexpression of Nlp in ovarian tumors raises the possibility that Nlp may play a role in ovarian carcinogenesis.

Changes in the transcriptional profile in response to overexpression of the osteopontin-c splice isoform in ovarian (OvCar-3) and prostate (PC-3) cancer cell lines

PubMed Central

2014-01-01

Background Especially in human tumor cells, the osteopontin (OPN) primary transcript is subject to alternative splicing, generating three isoforms termed OPNa, OPNb and OPNc. We previously demonstrated that the OPNc splice variant activates several aspects of the progression of ovarian and prostate cancers. The goal of the present study was to develop cell line models to determine the impact of OPNc overexpression on main cancer signaling pathways and thus obtain insights into the mechanisms of OPNc pro-tumorigenic roles. Methods Human ovarian and prostate cancer cell lines, OvCar-3 and PC-3 cells, respectively, were stably transfected to overexpress OPNc. Transcriptomic profiling was performed on these cells and compared to controls, to identify OPNc overexpression-dependent changes in gene expression levels and pathways by qRT-PCR analyses. Results Among 84 genes tested by using a multiplex real-time PCR Cancer Pathway Array approach, 34 and 16, respectively, were differentially expressed between OvCar-3 and PC-3 OPNc-overexpressing cells in relation to control clones. Differentially expressed genes are included in all main hallmarks of cancer, and several interacting proteins have been identified using an interactome network analysis. Based on marked up-regulation of Vegfa transcript in response to OPNc overexpression, we partially validated the array data by demonstrating that conditioned medium (CM) secreted from OvCar-3 and PC-3 OPNc-overexpressing cells significantly induced endothelial cell adhesion, proliferation and migration, compared to CM secreted from control cells. Conclusions Overall, the present study elucidated transcriptional changes of OvCar-3 and PC-3 cancer cell lines in response to OPNc overexpression, which provides an assessment for predicting the molecular mechanisms by which this splice variant promotes tumor progression features. PMID:24928374

Overexpression of angiotensin II type 2 receptor promotes apoptosis and impairs insulin secretion in rat insulinoma cells.

PubMed

Liu, Min; Jing, Danqing; Wang, Yan; Liu, Yu; Yin, Shinan

2015-02-01

Angiotensin II (Ang II), the major effector hormone of renin-angiotensin system, acts as a promoter of insulin resistance and diabetes mellitus type 2 pathogenesis. Activation of Ang II type 2 receptor (AT2R) has been examined as a potential therapeutic strategy. However, there are conflicting findings regarding the role of AT2R. In the current study, we evaluated the effects of overexpressing AT2R by viral vector transduction on the apoptosis and function of pancreatic β-islet cells. The rat insulinoma cell line, INS-1, was transduced with a recombinant adenoviral vector expressing AT2R (Ad-G-AT2R-EGFP). AT2R overexpression resulted in significantly reduced cell viability and subsequently impaired glucose-stimulated insulin secretion (GSIS) function in INS-1 cells. Down-regulated expressions of GSIS pathway components, insulin, glucose transporter 2, and glucokinase were associated with AT2R overexpression. Further analysis determined that overexpression of AT2R induced G1-phase cell cycle arrest and Ang II-independent apoptotic cell death as indicated by increased Annexin V staining. To understand the apoptosis signaling triggered by AT2R overexpression, levels of caspase proteins were measured. Overexpression of AT2R significantly induced caspase-8, caspase-9, and caspase-3 cleavage, and decreased Bcl-2, pAkt, and pERK expression levels. AT2R-induced cell apoptosis was successfully blocked by the caspase inhibitor Z-VAD-FMK. Our findings suggested that AT2R overexpression triggers the apoptosis of INS-1 cells and dysfunction in insulin secretion. In conclusion, more careful design and consideration are required when applying AT2R-related therapies in treating diabetes.

Over-expression of XIST, the Master Gene for X Chromosome Inactivation, in Females With Major Affective Disorders

PubMed Central

Ji, Baohu; Higa, Kerin K.; Kelsoe, John R.; Zhou, Xianjin

2015-01-01

Background Psychiatric disorders are common mental disorders without a pathological biomarker. Classic genetic studies found that an extra X chromosome frequently causes psychiatric symptoms in patients with either Klinefelter syndrome (XXY) or Triple X syndrome (XXX). Over-dosage of some X-linked escapee genes was suggested to cause psychiatric disorders. However, relevance of these rare genetic diseases to the pathogenesis of psychiatric disorders in the general population of psychiatric patients is unknown. Methods XIST and several X-linked genes were studied in 36 lymphoblastoid cell lines from healthy females and 60 lymphoblastoid cell lines from female patients with either bipolar disorder or recurrent major depression. XIST and KDM5C expression was also quantified in 48 RNA samples from postmortem human brains of healthy female controls and female psychiatric patients. Findings We found that the XIST gene, a master in control of X chromosome inactivation (XCI), is significantly over-expressed (p = 1 × 10− 7, corrected after multiple comparisons) in the lymphoblastoid cells of female patients with either bipolar disorder or major depression. The X-linked escapee gene KDM5C also displays significant up-regulation (p = 5.3 × 10− 7, corrected after multiple comparisons) in the patients' cells. Expression of XIST and KDM5C is highly correlated (Pearson's coefficient, r = 0.78, p = 1.3 × 10− 13). Studies on human postmortem brains supported over-expression of the XIST gene in female psychiatric patients. Interpretations We propose that over-expression of XIST may cause or result from subtle alteration of XCI, which up-regulates the expression of some X-linked escapee genes including KDM5C. Over-expression of X-linked genes could be a common mechanism for the development of psychiatric disorders between patients with those rare genetic diseases and the general population of female psychiatric patients with XIST over-expression. Our studies suggest that XIST and KDM5C expression could be used as a biological marker for diagnosis of psychiatric disorders in a significantly large subset of female patients. Research in context Due to lack of biological markers, diagnosis and treatment of psychiatric disorders are subjective. There is utmost urgency to identify biomarkers for clinics, research, and drug development. We found that XIST and KDM5C gene expression may be used as a biological marker for diagnosis of major affective disorders in a significantly large subset of female patients from the general population. Our studies show that over-expression of XIST and some X-linked escapee genes may be a common mechanism for development of psychiatric disorders between the patients with rare genetic diseases (XXY or XXX) and the general population of female psychiatric patients. PMID:26425698

Let-7 microRNA and HMGA2 levels of expression are not inversely linked in adipocytic tumors: analysis of 56 lipomas and liposarcomas with molecular cytogenetic data.

PubMed

Bianchini, Laurence; Saâda, Esma; Gjernes, Elisabet; Marty, Marion; Haudebourg, Juliette; Birtwisle-Peyrottes, Isabelle; Keslair, Frédérique; Chignon-Sicard, Bérangère; Chamorey, Emmanuel; Pedeutour, Florence

2011-06-01

The aim of our study was first to assess the role of HMGA2 expression in the pathogenesis of adipocytic tumors (AT) and, second, to seek a potential correlation between overexpression of HMGA2 and let-7 expression inhibition by analyzing a series of 56 benign and malignant AT with molecular cytogenetic data. We measured the levels of expression of HMGA2 mRNA and of eight members of the let-7 microRNA family using quantitative RT-PCR and expression of HMGA2 protein using immunohistochemistry. HMGA2 was highly overexpressed in 100% of well-differentiated/dedifferentiated liposarcomas (WDLPS/DDLPS), all with HMGA2 amplification, and 100% of lipomas with HMGA2 rearrangement. Overexpression of HMGA2 mRNA was detected in 76% of lipomas without HMGA2 rearrangement. HMGA2 protein expression was detected in 100% of lipomas with HMGA2 rearrangement and 48% of lipomas without HMGA2 rearrangement. We detected decreased expression levels of some let-7 members in a significant proportion of AT. Notably, let-7b and let-7g were inhibited in 61% of WDLPS/DDLPS. In lipomas, each type of let-7 was inhibited in approximately one-third of the cases. Although overexpression of both HMGA2 mRNA and protein in a majority of ordinary lipomas without HMGA2 structural rearrangement may have suggested a potential role for let-7 microRNAs, we did not observe a significant link with let-7 inhibition in such cases. Our results indicate that inhibition of let-7 microRNA expression may participate in the deregulation of HMGA2 in AT but that this inhibition is neither a prominent stimulator for HMGA2 overexpression nor a surrogate to genomic HMGA2 rearrangements. Copyright © 2011 Wiley-Liss, Inc.

TAZ Expression as a Prognostic Indicator in Colorectal Cancer

PubMed Central

Tham, Jill M.; Zhang, Xiaoqian; Zeng, Qi; Zhang, Shu-Dong; Hong, WanJin

2013-01-01

The Hippo pathway restricts the activity of transcriptional coactivators TAZ (WWTR1) and YAP. TAZ and YAP are reported to be overexpressed in various cancers, however, their prognostic significance in colorectal cancers remains unstudied. The expression levels of TAZ and YAP, and their downstream transcriptional targets, AXL and CTGF, were extracted from two independent colon cancer patient datasets available in the Gene Expression Omnibus database, totaling 522 patients. We found that mRNA expressions of both TAZ and YAP were positively correlated with those of AXL and CTGF (p<0.05). High level mRNA expression of TAZ, AXL or CTGF significantly correlated with shorter survival. Importantly, patients co-overexpressing all 3 genes had a significantly shorter survival time, and combinatorial expression of these 3 genes was an independent predictor for survival. The downstream target genes for TAZ-AXL-CTGF overexpression were identified by Java application MyStats. Interestingly, genes that are associated with colon cancer progression (ANTXR1, EFEMP2, SULF1, TAGLN, VCAN, ZEB1 and ZEB2) were upregulated in patients co-overexpressing TAZ-AXL-CTGF. This TAZ-AXL-CTGF gene expression signature (GES) was then applied to Connectivity Map to identify small molecules that could potentially be utilized to reverse this GES. Of the top 20 small molecules identified by connectivity map, amiloride (a potassium sparing diuretic,) and tretinoin (all-trans retinoic acid) have shown therapeutic promise in inhibition of colon cancer cell growth. Using MyStats, we found that low level expression of either ANO1 or SQLE were associated with a better prognosis in patients who co-overexpressed TAZ-AXL-CTGF, and that ANO1 was an independent predictor of survival together with TAZ-AXL-CTGF. Finally, we confirmed that TAZ regulates Axl, and plays an important role in clonogenicity and non-adherent growth in vitro and tumor formation in vivo. These data suggest that TAZ could be a therapeutic target for the treatment of colon cancer. PMID:23372686

Protein kinase C delta overexpressing transgenic mice are resistant to chemically but not to UV radiation-induced development of squamous cell carcinomas: a possible link to specific cytokines and cyclooxygenase-2.

PubMed

Aziz, Moammir H; Wheeler, Deric L; Bhamb, Bhushan; Verma, Ajit K

2006-01-15

Protein kinase C delta (PKCdelta), a Ca(2+)-independent, phospholipid-dependent serine/threonine kinase, is among the novel PKCs (delta, epsilon, and eta) expressed in mouse epidermis. We reported that FVB/N transgenic mice that overexpress ( approximately 8-fold) PKCdelta protein in basal epidermal cells and cells of the hair follicle are resistant to the development of both skin papillomas and squamous cell carcinoma (SCC) elicited by 7,12-dimethylbenz(a)anthracene initiation and 12-O-tetradecanoylphorbol-13-acetate (TPA) promotion protocol. We now present that PKCdelta overexpression in transgenic mice failed to suppress the induction of SCC developed by repeated exposures to UV radiation (UVR), the environmental carcinogen linked to the development of human SCC. Both TPA and UVR treatment of wild-type mice (a) increased the expression of proliferating cell nuclear antigen (PCNA) and apoptosis; (b) stimulated the expression of cytokines tumor necrosis factor-alpha (TNF-alpha), granulocyte macrophage colony-stimulating factor (GM-CSF), and granulocyte CSF (G-CSF); and (c) increased cyclooxygenase-2 (COX-2) expression and expression of phosphorylated Akt (p-Akt), p38, extracellular signal-regulated kinase-1 (ERK1), and ERK2. PKCdelta overexpression in transgenic mice enhanced TPA-induced but not UVR-induced apoptosis and suppressed TPA-stimulated but not UVR-stimulated levels of cell PCNA, cytokines (TNF-alpha, G-CSF, and GM-CSF), and the expression of COX-2, p-Akt, and p38. The results indicate that UVR-mediated signal transduction pathway to the induction of SCC does not seem to be sensitive to PKCdelta overexpression. The proapoptotic activity of PKCdelta coupled with its ability to suppress TPA-induced expression of proinflammatory cytokines, COX-2 expression, and the phosphorylation of Akt and p38 may play roles in the suppression of TPA-promoted development of SCC.

Overexpression of a novel cell cycle regulator ecdysoneless in breast cancer: a marker of poor prognosis in HER2/neu-overexpressing breast cancer patients.

PubMed

Zhao, Xiangshan; Mirza, Sameer; Alshareeda, Alaa; Zhang, Ying; Gurumurthy, Channabasavaiah Basavaraju; Bele, Aditya; Kim, Jun Hyun; Mohibi, Shakur; Goswami, Monica; Lele, Subodh M; West, William; Qiu, Fang; Ellis, Ian O; Rakha, Emad A; Green, Andrew R; Band, Hamid; Band, Vimla

2012-07-01

Uncontrolled proliferation is one of the hallmarks of breast cancer. We have previously identified the human Ecd protein (human ortholog of Drosophila Ecdysoneless, hereafter called Ecd) as a novel promoter of mammalian cell cycle progression, a function related to its ability to remove the repressive effects of Rb-family tumor suppressors on E2F transcription factors. Given the frequent dysregulation of cell cycle regulatory components in human cancer, we used immunohistochemistry of paraffin-embedded tissues to examine Ecd expression in normal breast tissue versus tissues representing increasing breast cancer progression. Initial studies of a smaller cohort without outcomes information showed that Ecd expression was barely detectable in normal breast tissue and in hyperplasia of breast, but high levels of Ecd were detected in benign breast hyperplasia, ductal carcinoma in situ (DCIS) and infiltrating ductal carcinoma (IDCs) of the breast. In this cohort of 104 IDC patients, Ecd expression levels showed a positive correlation with higher grade (P=0.04). Further analyses of Ecd expression using a larger, independent cohort (954) confirmed these results, with a strong positive correlation of elevated Ecd expression with higher histological grade (P=0.013), mitotic index (P=0.032), and Nottingham Prognostic Index score (P=0.014). Ecd expression was positively associated with HER2/neu (P=0.002) overexpression, a known marker of poor prognosis in breast cancer. Significantly, increased Ecd expression showed a strong positive association with shorter breast cancer specific survival (BCSS) (P=0.008) and disease-free survival (DFS) (P=0.003) in HER2/neu overexpressing patients. Taken together, our results reveal Ecd as a novel marker for breast cancer progression and show that levels of Ecd expression predict poorer survival in Her2/neu overexpressing breast cancer patients.

Sirtuin 6 protects the heart from hypoxic damage

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

Maksin-Matveev, Anna; Kanfi, Yariv; Hochhauser, Edith

2015-01-01

Sirtuin 6 (SIRT6) is a protein associated with prolonged life expectancy. We investigated whether life extension is associated with cardioprotection against hypoxia. The proposed study is to develop approaches to reduce hypoxic damage through the use of the sirtuin pathway and to elucidate the mechanism involved. For that purpose we subjected cardiomyocytes from transgenic mice (TG) with over-expression of SIRT6, to hypoxic stress in cell cultures. We hypothesized that cardiomyocytes from transgenic mice subjected to prolonged hypoxia may release survival factors or fewer damage markers to protect them from hypoxic stress compared with wild type (WT) mice. Lactate dehydrogenase (LDH)more » and creatine kinase (CK) released to the medium and propidium iodide (PI) binding, were markedly decreased following hypoxia in TG cardiomyocytes. The protective mechanism of SIRT6 over-expression includes the activation of pAMPKα pathway, the increased protein level of B-cell lymphoma 2 (Bcl2), the inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), the decrease of reactive oxygen species (ROS) and the reduction in the protein level of phospho-protein kinase B (pAkt) during hypoxia. Together, all these processes impede the necrosis/apoptosis pathways leading to the improved survival of cardiomyocytes following hypoxia, which might explain life extension. - Highlights: • Sirtuin 6 is a protein associated with prolonged life expectancy. • Over-expression of sirtuin 6 protects cardiocytes from hypoxia and oxidative stress. • Over-expression of sirtuin 6 activates the pAMPKα pathway and the Bcl2 expression. • Over-expression of sirtuin 6 decreases ROS formation and pAkt level during hypoxia. • These pathways protect cardiocytes from hypoxia and might explain lifespan extension.« less

MicroRNA-630 Suppresses Epithelial-to-Mesenchymal Transition by Regulating FoxM1 in Gastric Cancer Cells.

PubMed

Feng, Jing; Wang, Xiaojuan; Zhu, Weihua; Chen, Si; Feng, Changwei

2017-06-01

In the present study, we investigated the functional role of microRNA (miR)-630 in epithelial-to-mesenchymal transition (EMT) of gastric cancer (GC) cells, as well as the regulatory mechanism. Cells of human GC cell line SGC 7901 were transfected with miR-630 mimic or miR-630 inhibitor. The transfection efficiency was confirmed by qRT-PCR. Cell migration and invasion were determined by Transwell assay. Protein expression of E-cadherin, vimentin, and Forkhead box protein M1 (FoxM1) was tested by Western blot. Moreover, the expression of FoxM1 was elevated or suppressed, and then the effects of miR-630 abnormal expression on EMT and properties of migration and invasion were examined again, as well as protein expression of Ras/phosphoinositide 3-kinase (PI3K)/AKT related factors. The results showed that (i) the EMT and properties of migration and invasion were statistically decreased by overexpression of miR-630 compared to the control group but markedly increased by suppression of miR-630. However, (ii) abnormal expression of FoxM1 reversed these effects in GC cells. Moreover, (iii) expression of GTP-Rac1, p-PI3K, and p-AKT was decreased by miR-630 overexpression but increased by FoxM1 overexpression. (iv) The decreased levels of GTP-Rac1, p-PI3K, and p-AKT induced by miR-630 overexpression were dramatically elevated by simultaneous overexpression of FoxM1. In conclusion, our results suggest that miR-630 might be a tumor suppressor in GC cells. MiR-630 suppresses EMT by regulating FoxM1 in GC cells, supposedly via inactivation of the Ras/PI3K/AKT pathway.

c-myb stimulates cell growth by regulation of insulin-like growth factor (IGF) and IGF-binding protein-3 in K562 leukemia cells

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

Kim, Min-Sun; Kim, Sun-Young; Arunachalam, Sankarganesh

2009-07-17

c-myb plays an important role in the regulation of cell growth and differentiation, and is highly expressed in immature hematopoietic cells. The human chronic myelogenous leukemia cell K562, highly expresses IGF-I, IGF-II, IGF-IR, and IGF-induced cellular proliferation is mediated by IGF-IR. To characterize the impact of c-myb on the IGF-IGFBP-3 axis in leukemia cells, we overexpressed c-myb using an adenovirus gene transfer system in K562 cells. The overexpression of c-myb induced cell proliferation, compared to control, and c-myb induced cell growth was inhibited by anti-IGF-IR antibodies. c-myb overexpression resulted in a significant increase in the expression of IGF-I, IGF-II, andmore » IGF-IR, and a decrease in IGFBP-3 expression. By contrast, disruption of c-myb function by DN-myb overexpression resulted in significant reduction of IGF-I, IGF-II, IGF-IR, and elevation of IGFBP-3 expression. In addition, exogenous IGFBP-3 inhibited the proliferation of K562 cells, and c-myb induced cell growth was blocked by IGFBP-3 overexpression in a dose-dependent manner. The growth-promoting effects of c-myb were mediated through two major intracellular signaling pathways, Akt and Erk. Activation of Akt and Erk by c-myb was completely blocked by IGF-IR and IGFBP-3 antibodies. These findings suggest that c-myb stimulates cell growth, in part, by regulating expression of the components of IGF-IGFBP axis in K562 cells. In addition, disruption of c-myb function by DN-myb may provide a useful strategy for treatment of leukemia.« less

COX-2 overexpression in resected pancreatic head adenocarcinomas correlates with favourable prognosis

PubMed Central

2014-01-01

Background Overexpression of cyclooxygenase-2 (COX-2) has been implicated in oncogenesis and progression of adenocarcinomas of the pancreatic head. The data on the prognostic importance of COX expression in these tumours is inconsistent and conflicting. We evaluated how COX-2 overexpression affected overall postoperative survival in pancreatic head adenocarcinomas. Methods The study included 230 consecutive pancreatoduodenectomies for pancreatic cancer (PC, n = 92), ampullary cancer (AC, n = 62) and distal bile duct cancer (DBC, n = 76). COX-2 expression was assessed by immunohistochemistry. Associations between COX-2 expression and histopathologic variables including degree of differentiation, histopathologic type of differentiation (pancreatobiliary vs. intestinal) and lymph node ratio (LNR) were evaluated. Unadjusted and adjusted survival analysis was performed. Results COX-2 staining was positive in 71% of PC, 77% in AC and 72% in DBC. Irrespective of tumour origin, overall patient survival was more favourable in patients with COX-2 positive tumours than COX-2 negative (p = 0.043 in PC, p = 0.011 in AC, p = 0.06 in DBC). In tumours of pancreatobiliary type of histopathological differentiation, COX-2 expression did not significantly affect overall patient survival. In AC with intestinal differentiation COX-2 expression significantly predicted favourable survival (p = 0.003). In PC, COX-2 expression was significantly associated with high degree of differentiation (p = 0.002). COX-2 and LNR independently predicted good prognosis in a multivariate model. Conclusions COX-2 is overexpressed in pancreatic cancer, ampullary cancer and distal bile duct cancer and confers a survival benefit in all three cancer types. In pancreatic cancer, COX-2 overexpression is significantly associated with the degree of differentiation and independently predicts a favourable prognosis. PMID:24950702

Comparative Profiling of Primary Colorectal Carcinomas and Liver Metastases Identifies LEF1 as a Prognostic Biomarker

PubMed Central

Lin, Albert Y.; Chua, Mei-Sze; Choi, Yoon-La; Yeh, William; Kim, Young H.; Azzi, Raymond; Adams, Gregg A.; Sainani, Kristin; van de Rijn, Matt; So, Samuel K.; Pollack, Jonathan R.

2011-01-01

Purpose We sought to identify genes of clinical significance to predict survival and the risk for colorectal liver metastasis (CLM), the most common site of metastasis from colorectal cancer (CRC). Patients and Methods We profiled gene expression in 31 specimens from primary CRC and 32 unmatched specimens of CLM, and performed Significance Analysis of Microarrays (SAM) to identify genes differentially expressed between these two groups. To characterize the clinical relevance of two highly-ranked differentially-expressed genes, we analyzed the expression of secreted phosphoprotein 1 (SPP1 or osteopontin) and lymphoid enhancer factor-1 (LEF1) by immunohistochemistry using a tissue microarray (TMA) representing an independent set of 154 patients with primary CRC. Results Supervised analysis using SAM identified 963 genes with significantly higher expression in CLM compared to primary CRC, with a false discovery rate of <0.5%. TMA analysis showed SPP1 and LEF1 protein overexpression in 60% and 44% of CRC cases, respectively. Subsequent occurrence of CLM was significantly correlated with the overexpression of LEF1 (chi-square p = 0.042), but not SPP1 (p = 0.14). Kaplan Meier analysis revealed significantly worse survival in patients with overexpression of LEF1 (p<0.01), but not SPP1 (p = 0.11). Both univariate and multivariate analyses identified stage (p<0.0001) and LEF1 overexpression (p<0.05) as important prognostic markers, but not tumor grade or SPP1. Conclusion Among genes differentially expressed between CLM and primary CRC, we demonstrate overexpression of LEF1 in primary CRC to be a prognostic factor for poor survival and increased risk for liver metastasis. PMID:21383983

Several genes encoding ribosomal proteins are over-expressed in prostate-cancer cell lines: confirmation of L7a and L37 over-expression in prostate-cancer tissue samples.

PubMed

Vaarala, M H; Porvari, K S; Kyllönen, A P; Mustonen, M V; Lukkarinen, O; Vihko, P T

1998-09-25

A cDNA library specific for mRNA over-expressed in prostate cancer was generated by subtractive hybridization of transcripts originating from prostatic hyperplasia and cancer tissues. cDNA encoding ribosomal proteins L4, L5, L7a, L23a, L30, L37, S14 and S18 was found to be present among 100 analyzed clones. Levels of ribosomal mRNA were significantly higher at least in one of the prostate-cancer cell lines, LNCaP, DU-145 and PC-3, than in hyperplastic tissue, as determined by slot-blot hybridization. Furthermore, L23a- and S14-transcript levels were significantly elevated in PC-3 cells as compared with those in the normal prostate epithelial cell line PrEC. Generally, dramatic changes in the mRNA content of the ribosomal proteins were not detected, the most evident over-expression being that of L37 mRNA, which was 3.4 times more abundant in LNCaP cells than in hyperplastic prostate tissue. The over-expression of L7a and L37 mRNA was confirmed in prostate-cancer tissue samples by in situ hybridization. Elevated cancer-related expression of L4 and L30 has not been reported, but levels of the other ribosomal proteins are known to be increased in several types of cancers. These results therefore suggest that prostate cancer is comparable with other types of cancers, in that a larger pool of some ribosomal proteins is gained during the transformation process, by an unknown mechanism.

Heterogeneous Nuclear Ribonucleoprotein F Suppresses Angiotensinogen Gene Expression and Attenuates Hypertension and Kidney Injury in Diabetic Mice

PubMed Central

Lo, Chao-Sheng; Chang, Shiao-Ying; Chenier, Isabelle; Filep, Janos G.; Ingelfinger, Julie R.; Zhang, Shao Ling; Chan, John S.D.

2012-01-01

We investigated the impact of heterogeneous nuclear ribonucleoprotein F (hnRNP F) overexpression on angiotensinogen (Agt) gene expression, hypertension, and renal proximal tubular cell (RPTC) injury in high-glucose milieu both in vivo and in vitro. Diabetic Akita transgenic (Tg) mice specifically overexpressing hnRNP F in their RPTCs were created, and the effects on systemic hypertension, Agt gene expression, renal hypertrophy, and interstitial fibrosis were studied. We also examined immortalized rat RPTCs stably transfected with control plasmid or plasmid containing hnRNP F cDNA in vitro. The results showed that hnRNP F overexpression attenuated systemic hypertension, suppressed Agt and transforming growth factor-β1 (TGF-β1) gene expression, and reduced urinary Agt and angiotensin II levels, renal hypertrophy, and glomerulotubular fibrosis in Akita hnRNP F-Tg mice. In vitro, hnRNP F overexpression prevented the high-glucose stimulation of Agt and TGF-β1 mRNA expression and cellular hypertrophy in RPTCs. These data suggest that hnRNP F plays a modulatory role and can ameliorate hypertension, renal hypertrophy, and interstitial fibrosis in diabetes. The underlying mechanism is mediated, at least in part, via the suppression of intrarenal Agt gene expression in vivo. hnRNP F may be a potential target in the treatment of hypertension and kidney injury in diabetes. PMID:22664958

Hybrid proline-rich proteins: novel players in plant cell elongation?

PubMed Central

Dvořáková, Lenka; Srba, Miroslav; Opatrny, Zdenek; Fischer, Lukas

2012-01-01

Background and Aims Hybrid proline-rich proteins (HyPRPs) represent a large family of putative cell-wall proteins characterized by the presence of a variable N-terminal domain and a conserved C-terminal domain that is related to non-specific lipid transfer proteins. The function of HyPRPs remains unclear, but their widespread occurrence and abundant expression patterns indicate that they may be involved in a basic cellular process. Methods To elucidate the cellular function of HyPRPs, we modulated the expression of three HyPRP genes in tobacco (Nicotiana tabacum) BY-2 cell lines and in potato (Solanum tuberosum) plants. Key Results In BY-2 lines, over-expression of the three HyPRP genes with different types of N-terminal domains resulted in similar phenotypic changes, namely increased cell elongation, both in suspension culture and on solid media where the over-expression resulted in enhanced calli size. The over-expressing cells showed increased plasmolysis in a hypertonic mannitol solution and accelerated rate of protoplast release, suggesting loosening of the cell walls. In contrast to BY-2 lines, no phenotypic changes were observed in potato plants over-expressing the same or analogous HyPRP genes, presumably due to more complex compensatory mechanisms in planta. Conclusions Based on the results from BY-2 lines, we propose that HyPRPs, more specifically their C-terminal domains, represent a novel group of proteins involved in cell expansion. PMID:22028464

c-Ski overexpression promotes tumor growth and angiogenesis through inhibition of transforming growth factor-beta signaling in diffuse-type gastric carcinoma.

PubMed

Kiyono, Kunihiko; Suzuki, Hiroshi I; Morishita, Yasuyuki; Komuro, Akiyoshi; Iwata, Caname; Yashiro, Masakazu; Hirakawa, Kosei; Kano, Mitsunobu R; Miyazono, Kohei

2009-10-01

c-Ski, originally identified as a proto-oncogene product, is an important negative regulator of transforming growth factor (TGF)-beta family signaling through interaction with Smad2, Smad3, and Smad4. High expression of c-Ski has been found in some cancers, including gastric cancer. We previously showed that disruption of TGF-beta signaling by dominant-negative TGF-beta type II receptor in a diffuse-type gastric carcinoma model accelerated tumor growth through induction of tumor angiogenesis by decreased expression of the anti-angiogenic factor thrombospondin (TSP)-1. Here, we examined the function of c-Ski in human diffuse-type gastric carcinoma OCUM-2MLN cells. Overexpression of c-Ski inhibited TGF-beta signaling in OCUM-2MLN cells. Interestingly, c-Ski overexpression resulted in extensive acceleration of the growth of subcutaneous xenografts in BALB/c nu/nu female mice (6 weeks of age). Similar to tumors expressing dominant-negative TGF-beta type II receptor, histochemical studies revealed less fibrosis and increased angiogenesis in xenografted tumors expressing c-Ski compared to control tumors. Induction of TSP-1 mRNA by TGF-beta was attenuated by c-Ski in vitro, and expression of TSP-1 mRNA was decreased in tumors expressing c-Ski in vivo. These findings suggest that c-Ski overexpression promotes the growth of diffuse-type gastric carcinoma through induction of angiogenesis.

Folate receptor {alpha} regulates cell proliferation in mouse gonadotroph {alpha}T3-1 cells

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

Yao, Congjun; Evans, Chheng-Orn; Stevens, Victoria L.

We have previously found that the mRNA and protein levels of the folate receptor alpha (FR{alpha}) are uniquely over-expressed in clinically human nonfunctional (NF) pituitary adenomas, but the mechanistic role of FR{alpha} has not fully been determined. We investigated the effect of FR{alpha} over-expression in the mouse gonadotroph {alpha}T3-1 cell line as a model for NF pituitary adenomas. We found that the expression and function of FR{alpha} were strongly up-regulated, by Western blotting and folic acid binding assay. Furthermore, we found a higher cell growth rate, an enhanced percentage of cells in S-phase by BrdU assay, and a higher PCNAmore » staining. These observations indicate that over-expression of FR{alpha} promotes cell proliferation. These effects were abrogated in the same {alpha}T3-1 cells when transfected with a mutant FR{alpha} cDNA that confers a dominant-negative phenotype by inhibiting folic acid binding. Finally, by real-time quantitative PCR, we found that mRNA expression of NOTCH3 was up-regulated in FR{alpha} over-expressing cells. In summary, our data suggests that FR{alpha} regulates pituitary tumor cell proliferation and mechanistically may involve the NOTCH pathway. Potentially, this finding could be exploited to develop new, innovative molecular targeted treatment for human NF pituitary adenomas.« less

The Guanine Nucleotide Exchange Factor Tiam1 Affects Neuronal Morphology; Opposing Roles for the Small GTPases Rac and Rho

PubMed Central

van Leeuwen, Frank N.; Kain, Hendrie E.T.; van der Kammen, Rob A.; Michiels, Frits; Kranenburg, Onno W.; Collard, John G.

1997-01-01

The invasion-inducing T-lymphoma invasion and metastasis 1 (Tiam1) protein functions as a guanine nucleotide exchange factor (GEF) for the small GTPase Rac1. Differentiation-dependent expression of Tiam1 in the developing brain suggests a role for this GEF and its effector Rac1 in the control of neuronal morphology. Here we show that overexpression of Tiam1 induces cell spreading and affects neurite outgrowth in N1E-115 neuroblastoma cells. These effects are Rac-dependent and strongly promoted by laminin. Overexpression of Tiam1 recruits the α6β1 integrin, a laminin receptor, to specific adhesive contacts at the cell periphery, which are different from focal contacts. Cells overexpressing Tiam1 no longer respond to lysophosphatidic acid– induced neurite retraction and cell rounding, processes mediated by Rho, suggesting that Tiam1-induced activation of Rac antagonizes Rho signaling. This inhibition can be overcome by coexpression of constitutively active RhoA, which may indicate that regulation occurs at the level of Rho or upstream. Conversely, neurite formation induced by Tiam1 or Rac1 is further promoted by inactivating Rho. These results demonstrate that Rac- and Rho-mediated pathways oppose each other during neurite formation and that a balance between these pathways determines neuronal morphology. Furthermore, our data underscore the potential role of Tiam1 as a specific regulator of Rac during neurite formation and illustrate the importance of reciprocal interactions between the cytoskeleton and the extracellular matrix during this process. PMID:9348295

Overexpression of Arabidopsis thaliana brassinosteroid-related acyltransferase 1 gene induces brassinosteroid-deficient phenotypes in creeping bentgrass

PubMed Central

Han, Yun-Jeong; Kim, Young Soon; Hwang, Ok-Jin; Roh, Jeehee; Ganguly, Keya; Kim, Seong-Ki; Hwang, Ildoo

2017-01-01

Brassinosteroids (BRs) are naturally occurring steroidal hormones that play diverse roles in various processes during plant growth and development. Thus, genetic manipulation of endogenous BR levels might offer a way of improving the agronomic traits of crops, including plant architecture and stress tolerance. In this study, we produced transgenic creeping bentgrass (Agrostis stolonifera L.) overexpressing a BR-inactivating enzyme, Arabidopsis thaliana BR-related acyltransferase 1 (AtBAT1), which is known to catalyze the conversion of BR intermediates to inactive acylated conjugates. After putative transgenic plants were selected using herbicide resistance assay, genomic integration of the AtBAT1 gene was confirmed by genomic PCR and Southern blot analysis, and transgene expression was validated by northern blot analysis. The transgenic creeping bentgrass plants exhibited BR-deficient phenotypes, including reduced plant height with shortened internodes (i.e., semi-dwarf), reduced leaf growth rates with short, wide, and thick architecture, high chlorophyll contents, decreased numbers of vascular bundles, and large lamina joint bending angles (i.e., erect leaves). Subsequent analyses showed that the transgenic plants had significantly reduced amounts of endogenous BR intermediates, including typhasterol, 6-deoxocastasterone, and castasterone. Moreover, the AtBAT1 transgenic plants displayed drought tolerance as well as delayed senescence. Therefore, the results of the present study demonstrate that overexpression of an Arabidopsis BR-inactivating enzyme can reduce the endogenous levels of BRs in creeping bentgrass resulting in BR-deficient phenotypes, indicating that the AtBAT1 gene from a dicot plant is also functional in the monocot crop. PMID:29084267

Novel 5-fluorouracil-resistant human esophageal squamous cell carcinoma cells with dihydropyrimidine dehydrogenase overexpression

PubMed Central

Kikuchi, Osamu; Ohashi, Shinya; Nakai, Yukie; Nakagawa, Shunsaku; Matsuoka, Kazuaki; Kobunai, Takashi; Takechi, Teiji; Amanuma, Yusuke; Yoshioka, Masahiro; Ida, Tomomi; Yamamoto, Yoshihiro; Okuno, Yasushi; Miyamoto, Shin’ichi; Nakagawa, Hiroshi; Matsubara, Kazuo; Chiba, Tsutomu; Muto, Manabu

2015-01-01

5-Fluorouracil (5-FU) is a key drug for the treatment of esophageal squamous cell carcinoma (ESCC); however, resistance to it remains a critical limitation to its clinical use. To clarify the mechanisms of 5-FU resistance of ESCC, we originally established 5-FU-resistant ESCC cells, TE-5R, by step-wise treatment with continuously increasing concentrations of 5-FU. The half maximal inhibitory concentration of 5-FU showed that TE-5R cells were 15.6-fold more resistant to 5-FU in comparison with parental TE-5 cells. TE-5R cells showed regional copy number amplification of chromosome 1p including the DPYD gene, as well as high mRNA and protein expressions of dihydropyrimidine dehydrogenase (DPD), an enzyme involved in 5-FU degradation. 5-FU treatment resulted in a significant decrease of the intracellular 5-FU concentration and increase of the concentration of α-fluoro-ureidopropionic acid (FUPA), a metabolite of 5-FU, in TE-5R compared with TE-5 cells in vitro. Conversely, gimeracil, a DPD inhibitor, markedly increased the intracellular 5-FU concentration, decreased the intracellular FUPA concentration, and attenuated 5-FU resistance of TE-5R cells. These results indicate that 5-FU resistance of TE-5R cells is due to the rapid degradation of 5-FU by DPD overexpression. The investigation of 5-FU-resistant ESCC with DPYD gene copy number amplification and consequent DPD overexpression may generate novel biological evidence to explore strategies against ESCC with 5-FU resistance. PMID:26396918

Targeted overexpression of amelotin disrupts the microstructure of dental enamel.

PubMed

Lacruz, Rodrigo S; Nakayama, Yohei; Holcroft, James; Nguyen, Van; Somogyi-Ganss, Eszter; Snead, Malcolm L; White, Shane N; Paine, Michael L; Ganss, Bernhard

2012-01-01

We have previously identified amelotin (AMTN) as a novel protein expressed predominantly during the late stages of dental enamel formation, but its role during amelogenesis remains to be determined. In this study we generated transgenic mice that produce AMTN under the amelogenin (Amel) gene promoter to study the effect of AMTN overexpression on enamel formation in vivo. The specific overexpression of AMTN in secretory stage ameloblasts was confirmed by Western blot and immunohistochemistry. The gross histological appearance of ameloblasts or supporting cellular structures as well as the expression of the enamel proteins amelogenin (AMEL) and ameloblastin (AMBN) was not altered by AMTN overexpression, suggesting that protein production, processing and secretion occurred normally in transgenic mice. The expression of Odontogenic, Ameloblast-Associated (ODAM) was slightly increased in secretory stage ameloblasts of transgenic animals. The enamel in AMTN-overexpressing mice was much thinner and displayed a highly irregular surface structure compared to wild type littermates. Teeth of transgenic animals underwent rapid attrition due to the brittleness of the enamel layer. The microstructure of enamel, normally a highly ordered arrangement of hydroxyapatite crystals, was completely disorganized. Tomes' process, the hallmark of secretory stage ameloblasts, did not form in transgenic mice. Collectively our data demonstrate that the overexpression of amelotin has a profound effect on enamel structure by disrupting the formation of Tomes' process and the orderly growth of enamel prisms.

Targeted Overexpression of Amelotin Disrupts the Microstructure of Dental Enamel

PubMed Central

Lacruz, Rodrigo S.; Nakayama, Yohei; Holcroft, James; Nguyen, Van; Somogyi-Ganss, Eszter; Snead, Malcolm L.; White, Shane N.; Paine, Michael L.; Ganss, Bernhard

2012-01-01

We have previously identified amelotin (AMTN) as a novel protein expressed predominantly during the late stages of dental enamel formation, but its role during amelogenesis remains to be determined. In this study we generated transgenic mice that produce AMTN under the amelogenin (Amel) gene promoter to study the effect of AMTN overexpression on enamel formation in vivo. The specific overexpression of AMTN in secretory stage ameloblasts was confirmed by Western blot and immunohistochemistry. The gross histological appearance of ameloblasts or supporting cellular structures as well as the expression of the enamel proteins amelogenin (AMEL) and ameloblastin (AMBN) was not altered by AMTN overexpression, suggesting that protein production, processing and secretion occurred normally in transgenic mice. The expression of Odontogenic, Ameloblast-Associated (ODAM) was slightly increased in secretory stage ameloblasts of transgenic animals. The enamel in AMTN-overexpressing mice was much thinner and displayed a highly irregular surface structure compared to wild type littermates. Teeth of transgenic animals underwent rapid attrition due to the brittleness of the enamel layer. The microstructure of enamel, normally a highly ordered arrangement of hydroxyapatite crystals, was completely disorganized. Tomes' process, the hallmark of secretory stage ameloblasts, did not form in transgenic mice. Collectively our data demonstrate that the overexpression of amelotin has a profound effect on enamel structure by disrupting the formation of Tomes' process and the orderly growth of enamel prisms. PMID:22539960

Overexpression of Glucocorticoid Receptor β Enhances Myogenesis and Reduces Catabolic Gene Expression.

PubMed

Hinds, Terry D; Peck, Bailey; Shek, Evan; Stroup, Steven; Hinson, Jennifer; Arthur, Susan; Marino, Joseph S

2016-02-11

Unlike the glucocorticoid receptor α (GRα), GR β (GRβ) has a truncated ligand-binding domain that prevents glucocorticoid binding, implicating GRα as the mediator of glucocorticoid-induced skeletal muscle loss. Because GRβ causes glucocorticoid resistance, targeting GRβ may be beneficial in impairing muscle loss as a result of GRα activity. The purpose of this study was to determine how the overexpression of GRβ affects myotube formation and dexamethasone (Dex) responsiveness. We measured GR isoform expression in C₂C12 muscle cells in response to Dex and insulin, and through four days of myotube formation. Next, lentiviral-mediated overexpression of GRβ in C₂C12 was performed, and these cells were characterized for cell fusion and myotube formation, as well as sensitivity to Dex via the expression of ubiquitin ligases. GRβ overexpression increased mRNA levels of muscle regulatory factors and enhanced proliferation in myoblasts. GRβ overexpressing myotubes had an increased fusion index. Myotubes overexpressing GRβ had lower forkhead box O3 (Foxo3a) mRNA levels and a blunted muscle atrophy F-box/Atrogen-1 (MAFbx) and muscle ring finger 1 (MuRF1) response to Dex. We showed that GRβ may serve as a pharmacological target for skeletal muscle growth and protection from glucocorticoid-induced catabolic signaling. Increasing GRβ levels in skeletal muscle may cause a state of glucocorticoid resistance, stabilizing muscle mass during exposure to high doses of glucocorticoids.

Overexpression of SPAG9 in human gastric cancer is correlated with poor prognosis.

PubMed

Miao, Zhi-Feng; Wang, Zhen-Ning; Zhao, Ting-Ting; Xu, Ying-Ying; Wu, Jian-Hua; Liu, Xing-Yu; Xu, Hao; You, Yi; Xu, Hui-Mian

2015-11-01

Sperm associated antigen 9 (SPAG9) protein has been found to play an important role in cancer progression but the involved mechanisms are still obscure. Its clinical significance in human gastric cancers remains unexplored. In the present study, SPAG9 expression was analyzed in 147 gastric cancer specimens. We observed weak staining in normal gastric mucosa and positive staining in 65 out of 147 (44.2 %) cancer samples. Overexpression of SPAG9 correlated with local invasion (p = 0.0101), lymph node metastasis (p = 0.0488), TNM stage (p = 0.0002), and relapse (p = 0.0018). Importantly, SPAG9 overexpression correlated with poor overall survival (p = 0.0008). Furthermore, we performed siRNA knockdown of SPAG9 in HGC-27 cells with high endogenous expression and transfected SPAG9 plasmid in SGC-7901 cell line with low endogenous level. SPAG9 overexpression promoted while its depletion inhibited cell proliferation, cell cycle transition, and invasive cell growth. SPAG9 overxpression also increased chemoresistance to 5--fluorouracil (5-FU) in SGC-7901 cells. Further analysis showed that SPAG9 knockdown downregulated and its overexpression upregulated cyclin D1, MMP9, and p-p38 expression. In conclusion, SPAG9 overexpression in gastric cancer correlates with poor prognosis and contributes to gastric cancer cell proliferation, invasion, and chemoresistance. SPAG9 promotes gastric cancer invasion, possibly through p38-MMP9 signaling pathways.

Overexpression of PAD1 and FDC1 results in significant cinnamic acid decarboxylase activity in Saccharomyces cerevisiae.

PubMed

Richard, Peter; Viljanen, Kaarina; Penttilä, Merja

2015-01-01

The S. cerevisiae PAD1 gene had been suggested to code for a cinnamic acid decarboxylase, converting trans-cinnamic acid to styrene. This was suggested for the reason that the over-expression of PAD1 resulted in increased tolerance toward cinnamic acid, up to 0.6 mM. We show that by over-expression of the PAD1 together with the FDC1 the cinnamic acid decarboxylase activity can be increased significantly. The strain over-expressing PAD1 and FDC1 tolerated cinnamic acid concentrations up to 10 mM. The cooperation of Pad1p and Fdc1p is surprising since the PAD1 has a mitochondrial targeting sequence and the FDC1 codes for a cytosolic protein. The cinnamic acid decarboxylase activity was also seen in the cell free extract. The activity was 0.019 μmol per minute and mg of extracted protein. The overexpression of PAD1 and FDC1 resulted also in increased activity with the hydroxycinnamic acids ferulic acid, p-coumaric acid and caffeinic acid. This activity was not seen when FDC1 was overexpressed alone. An efficient cinnamic acid decarboxylase is valuable for the genetic engineering of yeast strains producing styrene. Styrene can be produced from endogenously produced L-phenylalanine which is converted by a phenylalanine ammonia lyase to cinnamic acid and then by a decarboxylase to styrene.

Absence of hyperplasia in Gasp-1 overexpressing mice is dependent on myostatin up-regulation.

PubMed

Brun, Caroline; Périé, Luce; Baraige, Fabienne; Vernus, Barbara; Bonnieu, Anne; Blanquet, Véronique

2014-01-01

Overexpression of Gasp-1, an inhibitor of myostatin, leads to a hypermuscular phenotype due to hypertrophy rather than hyperplasia in mice. However to date, the cellular and molecular mechanisms underlying this phenotype are not investigated. Skeletal muscles of overexpressing Gasp-1 mice, called Tg(Gasp-1) mice, were analyzed by histological methods. Satellite cell-derived myoblasts from these mice were used to investigate the molecular mechanisms. We demonstrated that hypertrophy in Tg(Gasp-1) mice was related to a myonuclear accretion during the first 3 postnatal weeks and an activation of the pro-hypertrophic Akt/mTORC/p70S6K signaling. In accordance with these results, we showed that overexpressing Gasp-1 primary myoblasts proliferated faster and myonuclei average per myotube was increased during differentiation. Molecular analysis revealed that Gasp-1 overexpression resulted in increased myostatin expression related to its auto-regulation. Despite its inhibition, myostatin led to Pax7 deregulation through its non-canonical Erk1/2 signaling pathway. Consistent with this, inhibition of Erk1/2 signaling pathway as well as neutralization of secreted myostatin rescue the Pax7 expression in overexpressing Gasp-1 myoblasts. Our study shows that myostatin is able to act independently of its canonical pathway to regulate the Pax7 expression. Altogether, our results indicate that myostatin could regulate muscle development despite its protein inhibition. © 2014 S. Karger AG, Basel.

Transfection with CXCR4 potentiates homing of mesenchymal stem cells in vitro and therapy of diabetic retinopathy in vivo.

PubMed

Wang, Jian; Zhang, Wei; He, Guang-Hui; Wu, Bin; Chen, Song

2018-01-01

To investigate the effect of the overexpression of C-X-C chemokine receptor type 4 (CXCR4) on homing of mesenchymal stem cells (MSCs) in vitro and therapeutic effects of diabetic retinopathy (DR) in vivo . MSCs were infected by lentivirus constructed with CXCR4. The expression of CXCR4 was examined by immunofluorescence, Western blot, and quantitative polymerase chain reaction. CXCR4-overexpressing MSCs were cultured in vitro to evaluate their chemotaxis, migration, and apoptotic activities. CXCR4-overexpressing MSCs were intravitreally injected to observe and compare their effects in a mouse model of DR. The histological structure of DR in rats was inspected by hematoxylin and eosin staining. The expression of rhodopsin, neuron-specific enolase (NSE), and inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α was examined by Western blot and immunohistochemical analyses. The transduction of MSCs by lentivirus was effective, and the transduced MSCs had high expression levels of CXCR4 gene and protein. Improved migration activities were observed in CXCR4-overexpressing MSCs. Further, reduced retinal damage, upregulation of rhodopsin and NSE protein, and downregulation of inflammatory cytokines IL-6 and TNF-α were observed in CXCR4-overexpressing MSCs in vivo . The homing of MSCs can be enhanced by upregulating CXCR4 levels, possibly improving histological structures of DR. CXCR4-overexpressing MSCs can be a novel strategy for treating DR.

Arabidopsis DREB2C modulates ABA biosynthesis during germination.

PubMed

Je, Jihyun; Chen, Huan; Song, Chieun; Lim, Chae Oh

2014-09-12

Plant dehydration-responsive element binding factors (DREBs) are transcriptional regulators of the APETELA2/Ethylene Responsive element-binding Factor (AP2/ERF) family that control expression of abiotic stress-related genes. We show here that under conditions of mild heat stress, constitutive overexpression seeds of transgenic DREB2C overexpression Arabidopsis exhibit delayed germination and increased abscisic acid (ABA) content compared to untransformed wild-type (WT). Treatment with fluridone, an inhibitor of the ABA biosynthesis abrogated these effects. Expression of an ABA biosynthesis-related gene, 9-cis-epoxycarotenoid dioxygenase 9 (NCED9) was up-regulated in the DREB2C overexpression lines compared to WT. DREB2C was able to trans-activate expression of NCED9 in Arabidopsis leaf protoplasts in vitro. Direct and specific binding of DREB2C to a complete DRE on the NCED9 promoter was observed in electrophoretic mobility shift assays. Exogenous ABA treatment induced DREB2C expression in germinating seeds of WT. Vegetative growth of transgenic DREB2C overexpression lines was more strongly inhibited by exogenous ABA compared to WT. These results suggest that DREB2C is a stress- and ABA-inducible gene that acts as a positive regulator of ABA biosynthesis in germinating seeds through activating NCED9 expression. Copyright © 2014 Elsevier Inc. All rights reserved.

YB-1 overexpression promotes a TGF-β1-induced epithelial–mesenchymal transition via Akt activation

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

Ha, Bin; Lee, Eun Byul; Cui, Jun

2015-03-06

The Y-box binding protein-1 (YB-1) is a transcription/translation regulatory protein, and the expression thereof is associated with cancer aggressiveness. In the present study, we explored the regulatory effects of YB-1 during the transforming growth factor-β1 (TGF-β1)-induced epithelial-to-mesenchymal transition (EMT) in lung adenocarcinoma cells. Downregulation of YB-1 increased E-cadherin promoter activity, and upregulation of YB-1 decreased promoter activity, suggesting that the YB-1 level may be correlated with the EMT. TGF-β1 induced YB-1 expression, and TGF-β1 translocated cytosolic YB-1 into the nucleus. YB-1 overexpression promoted TGF-β1-induced downregulation of epithelial markers, upregulation of mesenchymal markers, and cell migration. Moreover, YB-1 overexpression enhanced themore » expression of E-cadherin transcriptional repressors via TGF-β1-induced Akt activation. Our findings afford new insights into the role played by YB-1 in the TGF-β1 signaling pathway. - Highlights: • YB-1 regulates E-cadherin expression in A549 cells. • TGF-β1 induces upregulating and nuclear localization of YB-1. • YB-1 overexpression accelerates TGF-β1-induced EMT and cell migration. • YB-1 regulates Snail and Slug expression via Akt activation.« less

Pectin engineering to modify product quality in potato.

PubMed

Ross, Heather A; Morris, Wayne L; Ducreux, Laurence J M; Hancock, Robert D; Verrall, Susan R; Morris, Jenny A; Tucker, Gregory A; Stewart, Derek; Hedley, Pete E; McDougall, Gordon J; Taylor, Mark A

2011-10-01

Although processed potato tuber texture is an important trait that influences consumer preference, a detailed understanding of tuber textural properties at the molecular level is lacking. Previous work has identified tuber pectin methyl esterase (PME) activity as a potential factor impacting on textural properties, and the expression of a gene encoding an isoform of PME (PEST1) was associated with cooked tuber textural properties. In this study, a transgenic approach was undertaken to investigate further the impact of the PEST1 gene. Antisense and over-expressing potato lines were generated. In over-expressing lines, tuber PME activity was enhanced by up to 2.3-fold; whereas in antisense lines, PME activity was decreased by up to 62%. PME isoform analysis indicated that the PEST1 gene encoded one isoform of PME. Analysis of cell walls from tubers from the over-expressing lines indicated that the changes in PME activity resulted in a decrease in pectin methylation. Analysis of processed tuber texture demonstrated that the reduced level of pectin methylation in the over-expressing transgenic lines was associated with a firmer processed texture. Thus, there is a clear link between PME activity, pectin methylation and processed tuber textural properties. © 2011 The Authors. Plant Biotechnology Journal © 2011 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

Over-expression of TaMYB33 encoding a novel wheat MYB transcription factor increases salt and drought tolerance in Arabidopsis.

PubMed

Qin, Yuxiang; Wang, Mengcheng; Tian, Yanchen; He, Wenxing; Han, Lu; Xia, Guangmin

2012-06-01

Salt and drought stresses often adversely affect plant growth and productivity, MYB transcription factors have been shown to participate in the response to these stresses. Here we identified a new R2R3-type MYB transcription factor gene TaMYB33 from wheat (Triticum aestivum). TaMYB33 was induced by NaCl, PEG and ABA treatments, and its promoter sequence contains putative ABRE, MYB and other abiotic stress related cis-elements. Ectopic over-expression of TaMYB33 in Arabidopsis thaliana remarkably enhanced its tolerance to drought and NaCl stresses, but not to LiCl and KCl treatments. The expressions of AtP5CS and AtZAT12 which mirror the activities of proline and ascorbate peroxidase synthesis respectively were induced in TaMYB33 over-expression lines, indicating TaMYB33 promotes the ability for osmotic pressure balance-reconstruction and reactive oxidative species (ROS) scavenging. The up-regulation of AtAAO3 along with down-regulation of AtABF3, AtABI1 in TaMYB33 over-expression lines indicated that ABA synthesis was elevated while its signaling was restricted. These results suggest that TaMYB33 enhances salt and drought tolerance partially through superior ability for osmotic balance reconstruction and ROS detoxification.

Overexpressed homeobox B9 regulates oncogenic activities by transforming growth factor-β1 in gliomas

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

Fang, Liping; Xu, Yinghui; Zou, Lijuan, E-mail: zoulijuantg@126.com

2014-03-28

Highlights: • HOXB9 is overexpressed in gliomas. • HOXB9 over expression had shorter survival time than down expression in gliomas. • HOXB9 stimulated the proliferation, migration and sphere formation of glioma cells. • Activation of TGF-β1 contributed to HOXB9-induced oncogenic activities. - Abstract: Glioma is the leading cause of deaths related to tumors in the central nervous system. The mechanisms of gliomagenesis remain elusive to date. Homeobox B9 (HOXB9) has a crucial function in the regulation of gene expression and cell survival, but its functions in glioma formation and development have yet to be elucidated. This study showed that HOXB9more » expression in glioma tissues was significantly higher than that in nontumor tissues. Higher HOXB9 expression was also significantly associated with advanced clinical stage in glioma patients. HOXB9 overexpression stimulated the proliferation, migration, and sphere formation of glioma cells, whereas HOXB9 knockdown elicited an opposite effect. HOXB9 overexpression also increased the tumorigenicity of glioma cells in vivo. Moreover, the activation of transforming growth factor-β1 contributed to HOXB9-induced oncogenic activities. HOXB9 could be used as a predictable biomarker to be detected in different pathological and histological subtypes in glioma for diagnosis or prognosis.« less

PPARs and the Cardiovascular System

PubMed Central

Hamblin, Milton; Chang, Lin; Fan, Yanbo; Zhang, Jifeng

2009-01-01

Abstract Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear hormone-receptor superfamily. Originally cloned in 1990, PPARs were found to be mediators of pharmacologic agents that induce hepatocyte peroxisome proliferation. PPARs also are expressed in cells of the cardiovascular system. PPARγ appears to be highly expressed during atherosclerotic lesion formation, suggesting that increased PPARγ expression may be a vascular compensatory response. Also, ligand-activated PPARγ decreases the inflammatory response in cardiovascular cells, particularly in endothelial cells. PPARα, similar to PPARγ, also has pleiotropic effects in the cardiovascular system, including antiinflammatory and antiatherosclerotic properties. PPARα activation inhibits vascular smooth muscle proinflammatory responses, attenuating the development of atherosclerosis. However, PPARδ overexpression may lead to elevated macrophage inflammation and atherosclerosis. Conversely, PPARδ ligands are shown to attenuate the pathogenesis of atherosclerosis by improving endothelial cell proliferation and survival while decreasing endothelial cell inflammation and vascular smooth muscle cell proliferation. Furthermore, the administration of PPAR ligands in the form of TZDs and fibrates has been disappointing in terms of markedly reducing cardiovascular events in the clinical setting. Therefore, a better understanding of PPAR-dependent and -independent signaling will provide the foundation for future research on the role of PPARs in human cardiovascular biology. Antioxid. Redox Signal. 11, 1415–1452. PMID:19061437

Increased Signaling via Adenosine A1 Receptors, Sleep Deprivation, Imipramine, and Ketamine Inhibit Depressive-like Behavior via Induction of Homer1a

PubMed Central

Serchov, Tsvetan; Clement, Hans-Willi; Schwarz, Martin K.; Iasevoli, Felice; Tosh, Dilip K.; Idzko, Marco; Jacobson, Kenneth A.; de Bartolomeis, Andrea; Normann, Claus; Biber, Knut; van Calker, Dietrich

2016-01-01

SUMMARY Major depressive disorder is among the most commonly diagnosed disabling mental diseases. Several non-pharmacological treatments of depression upregulate adenosine concentration and/or adenosine A1 receptors (A1R) in the brain. To test whether enhanced A1R signaling mediates antidepressant effects, we generated a transgenic mouse with enhanced doxycycline-regulated A1R expression, specifically in forebrain neurons. Upregulating A1R led to pronounced acute and chronic resilience toward depressive-like behavior in various tests. Conversely, A1R knockout mice displayed an increased depressive-like behavior and were resistant to the antidepressant effects of sleep deprivation (SD). Various antidepressant treatments increase homer1a expression in medial prefrontal cortex (mPFC). Specific siRNA knockdown of homer1a in mPFC enhanced depressive-like behavior and prevented the antidepressant effects of A1R upregulation, SD, imipramine, and ketamine treatment. In contrast, viral overexpression of homer1a in the mPFC had antidepressant effects. Thus, increased expression of homer1a is a final common pathway mediating the antidepressant effects of different antidepressant treatments. PMID:26247862

ADAM15 expression is downregulated in melanoma metastasis compared to primary melanoma

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

Ungerer, Christopher; Doberstein, Kai; Buerger, Claudia

2010-10-22

Research highlights: {yields} Strong ADAM15 expression is found in normal melanocytes. {yields} ADAM15 expression is significantly downregulated in patients with melanoma metastasis. {yields} TGF-{beta} can downregulate ADAM15 expression in melanoma cells. {yields} Overexpression of ADAM15 in melanoma cells inhibits migration, proliferation and invasion of melanoma cells. {yields} Conclusion: ADAM15 represents an tumor suppressor protein in melanoma. -- Abstract: In a mouse melanoma metastasis model it has been recently shown that ADAM15 overexpression in melanoma cells significantly reduced the number of metastatic nodules on the lung. Unfortunately, the expression of ADAM15 in human melanoma tissue has not been determined so far.more » In our study, we characterized the expression of ADAM15 in tissue micro-arrays of patients with primary melanoma with melanoma metastasis. ADAM15 was expressed in melanocytes and endothelial cells of benign nevi and melanoma tissue. Importantly, ADAM15 was significantly downregulated in melanoma metastasis compared to primary melanoma. We further demonstrate that IFN-{gamma} and TGF-{beta} downregulate ADAM15 protein levels in melanoma cells. To investigate the role of ADAM15 in melanoma progression, we overexpressed ADAM15 in melanoma cells. Importantly, overexpression of ADAM15 in melanoma cells reduced the migration, invasion and the anchorage dependent and independent cell growth of melanoma cells. In summary, the downregulation of ADAM15 plays an important role in melanoma progression and ADAM15 act as a tumorsuppressor in melanoma.« less

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

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

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

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

Tian, Zhijie; Jiang, Hequn; Liu, Ying

MicroRNAs (miRNAs) are a class of small non-coding RNAs that function as critical gene regulators by targeting mRNAs for translational repression or degradation. In this study, we showed that the expression level of miR-133b was decreased, while Sirt1 mRNA expression levels were increased in hepatocellular carcinoma (HCC) and cell lines, and we identified Sirt1 as a novel direct target of miR-133b. The over-expression of miR-133b suppressed Sirt1 expression. In addition, miR-133b over-expression resulted in attenuating HCC cell proliferation and invasion together with apoptosis increase in vitro. HepG2 cell transplantation revealed that up-regulation of miR-133b could inhibit HCC tumor genesis inmore » vivo. Forced expression of Sirt1 partly rescued the effect of miR-133b in vitro. Furthermore, our study showed that miR-133b over-expression or Sirt1 down-regulation elevated E-cadherin expression, and repressed glypican-3 (GPC3) and the anti-apoptotic proteins (Bcl-2, Bcl-xL, and Mcl-1) expression. The inhibition of GPC3 expression repressed Bcl-2, Bcl-xL, and Mcl-1 expression, and elevated E-cadherin expression. Moreover, the Sirt1 up-regulation resulted in increases in HCC cell proliferation and invasion together with decreases apoptosis, and increases in the cytosolic accumulation and nuclear translocation of the transcription factor β-catenin in vitro. But the effect of Sirt1 up-regulation was partly reversed by GPC3 down-regulation in vitro. Taken together, these findings provide insight into the role and mechanism of miR-133b in regulating HCC cell proliferation, invasion and apoptosis via the miR-133b/Sirt1/GPC3/Wnt β-catenin axis, and miR-133b may serve as a potential therapeutic target in HCC in the future. - Highlights: • Sirt1 is a direct target of miR-133b in HCC. • miR-133b over-expression suppresses HCC progression in vitro and in vivo. • Sirt1 restoration reverses the effect of miR-133b over-expression on HCC cells. • GPC3 down-regulation reverses the effect of Sirt1 up-regulation on HCC cells. • Sirt1 activates Wnt β-catenin signaling by GPC3 in vitro.« less

Over-expressed maltose transporters in laboratory and lager yeasts: localization and competition with endogenous transporters.

PubMed

Vidgren, Virve; Londesborough, John

2018-05-31

Plain and fluorescently tagged versions of Agt1, Mtt1 and Malx1 maltose transporters were over-expressed in two laboratory yeasts and one lager yeast. The plain and tagged versions of each transporter supported similar transport activities, indicating that they are similarly trafficked and have similar catalytic activities. When they were expressed under the control of the strong constitutive PGK1 promoter only minor proportions of the fluorescent transporters were associated with the plasma membrane, the rest being found in intracellular structures. Transport activity of each tagged transporter in each host was roughly proportional to the plasma membrane-associated fluorescence. All three transporters were subject to glucose-triggered inactivation when the medium glucose concentration was abruptly raised. Results also suggest competition between endogenous and over-expressed transporters for access to the plasma membrane. This article is protected by copyright. All rights reserved.

Biosynthesis of isoprene in Escherichia coli via methylerythritol phosphate (MEP) pathway.

PubMed

Zhao, Yaru; Yang, Jianming; Qin, Bo; Li, Yonghao; Sun, Yuanzhang; Su, Sizheng; Xian, Mo

2011-06-01

Isoprene is an aviation fuel of high quality and an important polymer building block in the synthetic chemistry industry. In light of high oil prices, sustained availability, and environmental concerns, isoprene from renewable materials is contemplated as a substitute for petroleum-based product. Escherichia coli with advantages over other wild microorganisms, is considered as a powerful host for biofuels and chemicals. Here, we constructed a synthetic pathway of isoprene in E. coli by introducing an isoprene synthase (ispS) gene from Populus nigra, which catalyzes the conversion of dimethylallyl diphosphate (DMAPP) to isoprene. To improve the isoprene production, we overexpressed the native 1-deoxy-D: -xylulose-5-phosphate (DXP) synthase gene (dxs) and DXP reductoisomerase gene (dxr) in E. coli, which catalyzed the first step and the second step of MEP pathway, respectively. The fed-batch fermentation results showed that overexpression of DXS is helpful for the improvement of isoprene production. Surprisingly, heterologous expression of dxs and dxr from Bacillus subtilis in the E. coli expressing ispS resulted in a 2.3-fold enhancement of isoprene production (from 94 to 314 mg/L). The promising results showed that dxs and dxr from B. subtilis functioned more efficiently on the enhancement of isoprene production than native ones. This could be caused by the consequence of great difference in protein structures of the two original DXSs. It could be practical to produce isoprene in E. coli via MEP pathway through metabolic engineering. This work provides an alternative way for production of isoprene by engineered E. coli via MEP pathway through metabolic engineering.

CML8, an Arabidopsis Calmodulin-Like Protein, Plays a Role in Pseudomonas syringae Plant Immunity.

PubMed

Zhu, Xiaoyang; Robe, Eugénie; Jomat, Lucile; Aldon, Didier; Mazars, Christian; Galaud, Jean-Philippe

2017-02-01

Calcium is a universal second messenger involved in various cellular processes including plant development and stress responses. Its conversion into biological responses requires the presence of calcium sensor relays such as calmodulin (CaM) and calmodulin-like (CML) proteins. While the role of CaM is well described, the functions CML proteins remain largely uncharacterized. Here, we show that Arabidopsis CML8 expression is strongly and transiently induced by Pseudomonas syringae, and reverse genetic approaches indicated that the overexpression of CML8 confers on plants a better resistance to pathogenic bacteria compared with wild-type, knock-down and knock-out lines, indicating that CML8 participates as a positive regulator in plant immunity. However, this difference disappeared when inoculations were performed using bacteria unable to inject effectors into a plant host cell or deficient for some effectors known to target the salicylic acid (SA) signaling pathway. SA content and PR1 protein accumulation were altered in CML8 transgenic lines, supporting a role for CML8 in SA-dependent processes. Pathogen-associated molecular pattern (PAMP) treatments with flagellin and elf18 peptides have no effects on CML8 gene expression and do not modify root growth of CML8 knock-down and overexpressing lines compared with wild-type plants. Collectively, our results support a role for CML8 in plant immunity against P. syringae. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Cardiac acetylcholine inhibits ventricular remodeling and dysfunction under pathologic conditions.

PubMed

Roy, Ashbeel; Dakroub, Mouhamed; Tezini, Geisa C S V; Liu, Yin; Guatimosim, Silvia; Feng, Qingping; Salgado, Helio C; Prado, Vania F; Prado, Marco A M; Gros, Robert

2016-02-01

Autonomic dysfunction is a characteristic of cardiac disease and decreased vagal activity is observed in heart failure. Rodent cardiomyocytes produce de novo ACh, which is critical in maintaining cardiac homeostasis. We report that this nonneuronal cholinergic system is also found in human cardiomyocytes, which expressed choline acetyltransferase (ChAT) and the vesicular acetylcholine transporter (VAChT). Furthermore, VAChT expression was increased 3- and 1.5-fold at the mRNA and protein level, respectively, in ventricular tissue from patients with heart failure, suggesting increased ACh secretion in disease. We used mice with genetic deletion of cardiomyocyte-specific VAChT or ChAT and mice overexpressing VAChT to test the functional significance of cholinergic signaling. Mice deficient for VAChT displayed an 8% decrease in fractional shortening and 13% decrease in ejection fraction compared with angiotensin II (Ang II)-treated control animals, suggesting enhanced ventricular dysfunction and pathologic remodeling in response to Ang II. Similar results were observed in ChAT-deficient mice. Conversely, no decline in ventricular function was observed in Ang II-treated VAChT overexpressors. Furthermore, the fibrotic area was significantly greater (P < 0.05) in Ang II-treated VAChT-deficient mice (3.61 ± 0.64%) compared with wild-type animals (2.24 ± 0.11%). In contrast, VAChT overexpressing mice did not display an increase in collagen deposition. Our results provide new insight into cholinergic regulation of cardiac function, suggesting that a compensatory increase in cardiomyocyte VAChT levels may help offset cardiac remodeling in heart failure. © FASEB.

A dopamine receptor contributes to paraquat-induced neurotoxicity in Drosophila

PubMed Central

Cassar, Marlène; Issa, Abdul-Raouf; Riemensperger, Thomas; Petitgas, Céline; Rival, Thomas; Coulom, Hélène; Iché-Torres, Magali; Han, Kyung-An; Birman, Serge

2015-01-01

Long-term exposure to environmental oxidative stressors, like the herbicide paraquat (PQ), has been linked to the development of Parkinson's disease (PD), the most frequent neurodegenerative movement disorder. Paraquat is thus frequently used in the fruit fly Drosophila melanogaster and other animal models to study PD and the degeneration of dopaminergic neurons (DNs) that characterizes this disease. Here, we show that a D1-like dopamine (DA) receptor, DAMB, actively contributes to the fast central nervous system (CNS) failure induced by PQ in the fly. First, we found that a long-term increase in neuronal DA synthesis reduced DAMB expression and protected against PQ neurotoxicity. Secondly, a striking age-related decrease in PQ resistance in young adult flies correlated with an augmentation of DAMB expression. This aging-associated increase in oxidative stress vulnerability was not observed in a DAMB-deficient mutant. Thirdly, targeted inactivation of this receptor in glutamatergic neurons (GNs) markedly enhanced the survival of Drosophila exposed to either PQ or neurotoxic levels of DA, whereas, conversely, DAMB overexpression in these cells made the flies more vulnerable to both compounds. Fourthly, a mutation in the Drosophila ryanodine receptor (RyR), which inhibits activity-induced increase in cytosolic Ca2+, also strongly enhanced PQ resistance. Finally, we found that DAMB overexpression in specific neuronal populations arrested development of the fly and that in vivo stimulation of either DNs or GNs increased PQ susceptibility. This suggests a model for DA receptor-mediated potentiation of PQ-induced neurotoxicity. Further studies of DAMB signaling in Drosophila could have implications for better understanding DA-related neurodegenerative disorders in humans. PMID:25158689

CHES1/FOXN3 regulates cell proliferation by repressing PIM2 and protein biosynthesis

PubMed Central

Huot, Geneviève; Vernier, Mathieu; Bourdeau, Véronique; Doucet, Laurent; Saint-Germain, Emmanuelle; Gaumont-Leclerc, Marie-France; Moro, Alejandro; Ferbeyre, Gerardo

2014-01-01

The expression of the forkhead transcription factor checkpoint suppressor 1 (CHES1), also known as FOXN3, is reduced in many types of cancers. We show here that CHES1 decreases protein synthesis and cell proliferation in tumor cell lines but not in normal fibroblasts. Conversely, short hairpin RNA–mediated depletion of CHES1 increases tumor cell proliferation. Growth suppression depends on the CHES1 forkhead DNA-binding domain and correlates with the nuclear localization of CHES1. CHES1 represses the expression of multiple genes, including the kinases PIM2 and DYRK3, which regulate protein biosynthesis, and a number of genes in cilium biogenesis. CHES1 binds directly to the promoter of PIM2, and in cells expressing CHES1 the levels of PIM2 are reduced, as well as the phosphorylation of the PIM2 target 4EBP1. Overexpression of PIM2 or eIF4E partially reverses the antiproliferative effect of CHES1, indicating that PIM2 and protein biosynthesis are important targets of the antiproliferative effect of CHES1. In several human hematopoietic cancers, CHES1 and PIM2 expressions are inversely correlated, suggesting that repression of PIM2 by CHES1 is clinically relevant. PMID:24403608

CHES1/FOXN3 regulates cell proliferation by repressing PIM2 and protein biosynthesis.

PubMed

Huot, Geneviève; Vernier, Mathieu; Bourdeau, Véronique; Doucet, Laurent; Saint-Germain, Emmanuelle; Gaumont-Leclerc, Marie-France; Moro, Alejandro; Ferbeyre, Gerardo

2014-03-01

The expression of the forkhead transcription factor checkpoint suppressor 1 (CHES1), also known as FOXN3, is reduced in many types of cancers. We show here that CHES1 decreases protein synthesis and cell proliferation in tumor cell lines but not in normal fibroblasts. Conversely, short hairpin RNA-mediated depletion of CHES1 increases tumor cell proliferation. Growth suppression depends on the CHES1 forkhead DNA-binding domain and correlates with the nuclear localization of CHES1. CHES1 represses the expression of multiple genes, including the kinases PIM2 and DYRK3, which regulate protein biosynthesis, and a number of genes in cilium biogenesis. CHES1 binds directly to the promoter of PIM2, and in cells expressing CHES1 the levels of PIM2 are reduced, as well as the phosphorylation of the PIM2 target 4EBP1. Overexpression of PIM2 or eIF4E partially reverses the antiproliferative effect of CHES1, indicating that PIM2 and protein biosynthesis are important targets of the antiproliferative effect of CHES1. In several human hematopoietic cancers, CHES1 and PIM2 expressions are inversely correlated, suggesting that repression of PIM2 by CHES1 is clinically relevant.

Thioredoxin-1 promotes colorectal cancer invasion and metastasis through crosstalk with S100P.

PubMed

Lin, Feiyan; Zhang, Peili; Zuo, Zhigui; Wang, Fule; Bi, Ruichun; Shang, Wenjing; Wu, Aihua; Ye, Ju; Li, Shaotang; Sun, Xuecheng; Wu, Jianbo; Jiang, Lei

2017-08-10

Thioredoxin-1 (Trx-1) is a small redox-regulating protein, which plays an important role in several cellular functions. Despite recent advances in understanding the biology of Trx-1, the role of Trx-1 and its underlying signaling mechanism in colorectal cancer (CRC) metastasis have not been extensively studied. In this study, we observed that Trx-1 expression is increased in CRC tissues compared to the paired non-cancerous tissues and is significantly correlated with clinical staging, lymph node metastasis and poor survival. Overexpression of Trx-1 enhanced CRC cell invasion and metastasis in vitro and in vivo. Conversely, suppression of Trx-1 expression decreased cell invasion and metastasis in vitro and in vivo. Moreover, Trx-1 activates S100P gene transcription. S100P, in turn, promotes Trx-1 expression and nuclear localization by upregulating p-ERK1/2 and downregulating TXNIP expression. Our finding provides new insight into the mechanism of Trx-1/S100P axis in the promotion of CRC metastasis, and suggests that the Trx-1/S100P axis and their related signaling pathways could be novel targets for the treatment of metastatic CRC. Copyright © 2017 Elsevier B.V. All rights reserved.

Trefoil factor 3 is required for differentiation of thyroid follicular cells and acts as a context-dependent tumor suppressor.

PubMed

Abols, A; Ducena, K; Andrejeva, D; Sadovska, L; Zandberga, E; Vilmanis, J; Narbuts, Z; Tars, J; Eglitis, J; Pirags, V; Line, A

2015-01-01

Trefoil factor 3 (TFF3) is overexpressed in a variety of solid epithelial cancers, where it has been shown to promote migration, invasion, proliferation, survival and angiogenesis. On the contrary, in the majority of thyroid tumors, it is downregulated, yet its role in the development of thyroid cancer remains unknown. Here we show that TFF3 exhibits strong cytoplasmic staining of normal thyroid follicular cells and colloid and the staining is increased in hyperfunctioning thyroid nodules, while it is decreased in all thyroid cancers of follicular cell origin. By meta-analysis of gene expression datasets, we found that in the thyroid cancer, conversely to the breast cancer, the expression of TFF3 mRNA was downregulated by estrogen signaling and confirmed this by treating thyroid cancer cells with estradiol. Forced expression of TFF3 in anaplastic thyroid cancer cells resulted in decreased cell proliferation, clonal spheroid formation and entry into the S phase. Furthermore, it induced acquisition of epithelial-like cell morphology and expression of the differentiation markers of thyroid follicular cells and transcription factors implicated in the thyroid morphogenesis and function. Taken together, this study provides the first evidence that TFF3 may act as a tumor suppressor or an oncogene depending on the cellular context.

Association of PTP1B with Outcomes of Breast Cancer Patients Who Underwent Neoadjuvant Chemotherapy.

PubMed

Rivera Franco, Monica M; Leon Rodriguez, Eucario; Martinez Benitez, Braulio; Villanueva Rodriguez, Luisa G; de la Luz Sevilla Gonzalez, Maria; Armengol Alonso, Alejandra

2016-01-01

PTP1B is involved in the oncogenesis of breast cancer. In addition, neoadjuvant therapy has been widely used in breast cancer; thus, a measurement to assess survival improvement could be pathological complete response (pCR). Our objective was to associate PTP1B overexpression with outcomes of breast cancer patients who underwent neoadjuvant chemotherapy. Forty-six specimens were included. Diagnostic biopsies were immunostained using anti-PTP1B antibody. Expression was categorized as negative (<5%) and overexpression (≥5%). Patients' responses were graded according to the Miller-Payne system. Sixty-three percent of patients overexpressed PTP1B. There was no significant association between PTP1B overexpression and pCR ( P = 0.2). However, when associated with intrinsic subtypes, overexpression was higher in human epidermal growth factor receptor 2-positive-enriched specimens ( P = 0.02). Ten-year progression-free survival showed no differences. Our preliminary results do not show an association between PTP1B over-expression and pCR; however, given the limited sample and heterogeneous treatment in our cohort, this hypothesis cannot be excluded.

Correlation of HER-2 over-expression with clinico-pathological parameters in Tunisian breast carcinoma.

PubMed

Ayadi, Lobna; Khabir, Abdelmajid; Amouri, Habib; Karray, Sondes; Dammak, Abdallah; Guermazi, Mohamed; Boudawara, Tahya

2008-10-22

Breast carcinoma is a disease with a tremendous heterogeneity in its clinical behavior. Newer prognostic factors and predictors of response to therapy are needed. The aim of this study was to evaluate the expression of HER-2, estrogen receptor (ER) and progesterone receptors (PR) in breast carcinoma and to compare it with other prognostic parameters such as histological type and grade, tumor size, patients' age, and lymph node metastases. This is a retrospective study conducted in the department of pathology at Sfax University Hospital. Confirmed 155 Cases of breast carcinoma were reviewed in the period between January 2000 and December 2004. We used immunohistochemistry to evaluate the expression of HER-2, ER, and PR receptor and Chi-square and Fisher exact test to correlate immunohistochemical findings with prognostic parameters for breast carcinoma such as patients' age, tumor size, histological type, histological grade and lymph node status. The mean age of patients was 51.5 years, ranging from 22 to 89 years. 80 (51.6%) of the patients were below 50 years. The percentage of expression of HER-2, ER and PR was 26, 59.4, and 52.3%, respectively. HER-2 was over-expressed (3+) in 18.1% of the cases, was inversely related to ER expression (p = 0.00) and to PR expression (p = 0.048). This over-expression was also associated with a high tumor grade with marginal significance (p = 0.072). A negative correlation was noted between ER and PR expression and SBR grade (p = 0.000) and ER and age (p = 0.002). HER-2 over-expression was observed in 18.1% of Tunisian breast carcinoma affecting female patients. This group presents apparently an aggressive form of breast carcinoma with high histological grade and negative ER.

Analysis and interpretation of transcriptomic data obtained from extended Warburg effect genes in patients with clear cell renal cell carcinoma

PubMed Central

Sanders, Edward; Diehl, Svenja

2015-01-01

Background Many cancers adopt a metabolism that is characterized by the well-known Warburg effect (aerobic glycolysis). Recently, numerous attempts have been made to treat cancer by targeting one or more gene products involved in this pathway without notable success. This work outlines a transcriptomic approach to identify genes that are highly perturbed in clear cell renal cell carcinoma (CCRCC). Methods We developed a model of the extended Warburg effect and outlined the model using Cytoscape. Following this, gene expression fold changes (FCs) for tumor and adjacent normal tissue from patients with CCRCC (GSE6344) were mapped on to the network. Gene expression values with FCs of greater than two were considered as potential targets for treatment of CCRCC. Results The Cytoscape network includes glycolysis, gluconeogenesis, the pentose phosphate pathway (PPP), the TCA cycle, the serine/glycine pathway, and partial glutaminolysis and fatty acid synthesis pathways. Gene expression FCs for nine of the 10 CCRCC patients in the GSE6344 data set were consistent with a shift to aerobic glycolysis. Genes involved in glycolysis and the synthesis and transport of lactate were over-expressed, as was the gene that codes for the kinase that inhibits the conversion of pyruvate to acetyl-CoA. Interestingly, genes that code for unique proteins involved in gluconeogenesis were strongly under-expressed as was also the case for the serine/glycine pathway. These latter two results suggest that the role attributed to the M2 isoform of pyruvate kinase (PKM2), frequently the principal isoform of PK present in cancer: i.e. causing a buildup of glucose metabolites that are shunted into branch pathways for synthesis of key biomolecules, may not be operative in CCRCC. The fact that there was no increase in the expression FC of any gene in the PPP is consistent with this hypothesis. Literature protein data generally support the transcriptomic findings. Conclusions A number of key genes have been identified that could serve as valid targets for anti-cancer pharmaceutical agents. Genes that are highly over-expressed include ENO2, HK2, PFKP, SLC2A3, PDK1, and SLC16A1. Genes that are highly under-expressed include ALDOB, PKLR, PFKFB2, G6PC, PCK1, FBP1, PC, and SUCLG1. PMID:25859558

Overexpression of proto-oncogene FBI-1 activates membrane type 1-matrix metalloproteinase in association with adverse outcome in ovarian cancers.

PubMed

Jiang, Lili; Siu, Michelle K Y; Wong, Oscar G W; Tam, Kar Fai; Lam, Eric W-F; Ngan, Hextan Y S; Le, Xiao-Feng; Wong, Esther S Y; Chan, Hoi Yan; Cheung, Annie N Y

2010-12-21

FBI-1 (factor that binds to the inducer of short transcripts of human immunodeficiency virus-1) is a member of the POK (POZ and Kruppel) family of transcription factors and play important roles in cellular differentiation and oncogenesis. Recent evidence suggests that FBI-1 is expressed at high levels in a subset of human lymphomas and some epithelial solid tumors. However, the function of FBI-1 in human ovarian cancers remains elusive. In this study, we investigated the role of FBI-1 in human ovarian cancers, in particularly, its function in cancer cell invasion via modulating membrane type 1-matrix metalloproteinase (MT1-MMP). Significantly higher FBI-1 protein and mRNA expression levels were demonstrated in ovarian cancers samples and cell lines compared with borderline tumors and benign cystadenomas. Increased FBI-1 mRNA expression was correlated significantly with gene amplification (P = 0.037). Moreover, higher FBI-1 expression was found in metastatic foci (P = 0.036) and malignant ascites (P = 0.021), and was significantly associated with advanced stage (P = 0.012), shorter overall survival (P = 0.032) and disease-free survival (P = 0.016). In vitro, overexpressed FBI-1 significantly enhanced cell migration and invasion both in OVCA 420 and SKOV-3 ovarian carcinoma cells, irrespective of p53 status, accompanied with elevated expression of MT1-MMP, but not MMP-2 or TIMP-2. Moreover, knockdown of MT1-MMP abolished FBI-1-mediated cell migration and invasion. Conversely, stable knockdown of FBI-1 remarkably reduced the motility of these cells with decreased expression of MT1-MMP. Promoter assay and chromatin immunoprecipitation study indicated that FBI-1 could directly interact with the promoter spanning ~600 bp of the 5'-flanking sequence of MT1-MMP and enhanced its expression in a dose-dependent manner. Furthermore, stable knockdown and ectopic expression of FBI-1 decreased and increased cell proliferation respectively in OVCA 420, but not in the p53 null SKOV-3 cells. Our results suggested an important role of FBI-1 in ovarian cancer cell proliferation, cell mobility, and invasiveness, and that FBI-1 can be a potential target of chemotherapy.

Overexpression of proto-oncogene FBI-1 activates membrane type 1-matrix metalloproteinase in association with adverse outcome in ovarian cancers

PubMed Central

2010-01-01

Background FBI-1 (factor that binds to the inducer of short transcripts of human immunodeficiency virus-1) is a member of the POK (POZ and Kruppel) family of transcription factors and play important roles in cellular differentiation and oncogenesis. Recent evidence suggests that FBI-1 is expressed at high levels in a subset of human lymphomas and some epithelial solid tumors. However, the function of FBI-1 in human ovarian cancers remains elusive. Results In this study, we investigated the role of FBI-1 in human ovarian cancers, in particularly, its function in cancer cell invasion via modulating membrane type 1-matrix metalloproteinase (MT1-MMP). Significantly higher FBI-1 protein and mRNA expression levels were demonstrated in ovarian cancers samples and cell lines compared with borderline tumors and benign cystadenomas. Increased FBI-1 mRNA expression was correlated significantly with gene amplification (P = 0.037). Moreover, higher FBI-1 expression was found in metastatic foci (P = 0.036) and malignant ascites (P = 0.021), and was significantly associated with advanced stage (P = 0.012), shorter overall survival (P = 0.032) and disease-free survival (P = 0.016). In vitro, overexpressed FBI-1 significantly enhanced cell migration and invasion both in OVCA 420 and SKOV-3 ovarian carcinoma cells, irrespective of p53 status, accompanied with elevated expression of MT1-MMP, but not MMP-2 or TIMP-2. Moreover, knockdown of MT1-MMP abolished FBI-1-mediated cell migration and invasion. Conversely, stable knockdown of FBI-1 remarkably reduced the motility of these cells with decreased expression of MT1-MMP. Promoter assay and chromatin immunoprecipitation study indicated that FBI-1 could directly interact with the promoter spanning ~600bp of the 5'-flanking sequence of MT1-MMP and enhanced its expression in a dose-dependent manner. Furthermore, stable knockdown and ectopic expression of FBI-1 decreased and increased cell proliferation respectively in OVCA 420, but not in the p53 null SKOV-3 cells. Conclusions Our results suggested an important role of FBI-1 in ovarian cancer cell proliferation, cell mobility, and invasiveness, and that FBI-1 can be a potential target of chemotherapy. PMID:21176152

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

Yeung, Y.-S.; Yip, C.-W.; Hon, C.-C.

We have previously demonstrated that over-expression of spike protein (S) of severe acute respiratory syndrome coronavirus (SARS-CoV) or its C-terminal subunit (S2) is sufficient to induce apoptosis in vitro. To further investigate the possible roles of S2 in SARS-CoV-induced apoptosis and pathogenesis of SARS, we characterized the host expression profiles induced upon S2 over-expression in Vero E6 cells by oligonucleotide microarray analysis. Possible activation of mitochondrial apoptotic pathway in S2 expressing cells was suggested, as evidenced by the up-regulation of cytochrome c and down-regulation of the Bcl-2 family anti-apoptotic members. Inhibition of Bcl-2-related anti-apoptotic pathway was further supported by themore » diminution of S2-induced apoptosis in Vero E6 cells over-expressing Bcl-xL. In addition, modulation of CCN E2 and CDKN 1A implied the possible control of cell cycle arrest at G1/S phase. This study is expected to extend our understanding on the pathogenesis of SARS at a molecular level.« less

Bombesin related peptides/receptors and their promising therapeutic roles in cancer imaging, targeting and treatment

PubMed Central

Moreno, Paola; Ramos-Álvarez, Irene; Moody, Terry W.; Jensen, Robert T.

2016-01-01

Introduction Despite remarkable advances in tumor treatment, many patients still die from common tumors (breast, prostate, lung, CNS, colon, and pancreas), and thus, new approaches are needed. Many of these tumors synthesize bombesin (Bn)-related peptides and over-express their receptors (BnRs), hence functioning as autocrine-growth-factors. Recent studies support the conclusion that Bn-peptides/BnRs are well-positioned for numerous novel antitumor treatments, including interrupting autocrine-growth via the use of over-expressed receptors for imaging and targeting cytotoxic-compounds, either by direct-coupling or combined with nanoparticle-technology. Areas covered The unique ability of common neoplasms to synthesize, secrete, and show a growth/proliferative/differentiating response due to BnR over-expression, is reviewed, both in general and with regard to the most frequently investigated neoplasms (breast, prostate, lung, and CNS). Particular attention is paid to advances in the recent years. Also considered are the possible therapeutic approaches to the growth/differentiation effect of Bn-peptides, as well as the therapeutic implication of the frequent BnR over-expression for tumor-imaging and/or targeted-delivery. Expert opinion Given that Bn-related-peptides/BnRs are so frequently ectopically-expressed by common tumors, which are often malignant and become refractory to conventional treatments, therapeutic interventions using novel approaches to Bn-peptides and receptors are being explored. Of particular interest is the potential of reproducing BnRs in common tumors, such as the recent success of utilizing overexpression of somatostatin-receptors by neuroendocrine-tumors to provide the most sensitive imaging methods and targeted delivery of cytotoxic-compounds. PMID:26981612

Overexpression of Catalase in Vascular Smooth Muscle Cells Prevents the Formation of Abdominal Aortic Aneurysms

PubMed Central

Parastatidis, Ioannis; Weiss, Daiana; Joseph, Giji; Taylor, W Robert

2013-01-01

Objective Elevated levels of oxidative stress have been reported in abdominal aortic aneurysms (AAA), but which reactive oxygen species (ROS) promotes the development of AAA remains unclear. Here we investigate the effect of the hydrogen peroxide (H2O2) degrading enzyme catalase on the formation of AAA. Approach and Results AAA were induced with the application of calcium chloride (CaCl2) on mouse infrarenal aortas. The administration of PEG-catalase, but not saline, attenuated the loss of tunica media and protected against AAA formation (0.91±0.1 mm vs. 0.76±0.09 mm). Similarly, in a transgenic mouse model, catalase over-expression in the vascular smooth muscle cells (VSMC) preserved the thickness of tunica media and inhibited aortic dilatation by 50% (0.85±0.14 mm vs. 0.57±0.08 mm). Further studies showed that injury with CaCl2 decreased catalase expression and activity in the aortic wall. Pharmacologic administration or genetic over-expression of catalase restored catalase activity and subsequently decreased matrix metalloproteinase activity. In addition, a profound reduction in inflammatory markers and VSMC apoptosis was evident in aortas of catalase over-expressing mice. Interestingly, as opposed to infusion of PEG-catalase, chronic over-expression of catalase in VSMC did not alter the total aortic H2O2 levels. Conclusions The data suggest that a reduction in aortic wall catalase activity can predispose to AAA formation. Restoration of catalase activity in the vascular wall enhances aortic VSMC survival and prevents AAA formation primarily through modulation of matrix metalloproteinase activity. PMID:23950141

IK channel activation increases tumor growth and induces differential behavioral responses in two breast epithelial cell lines.

PubMed

Thurber, Amy E; Nelson, Michaela; Frost, Crystal L; Levin, Michael; Brackenbury, William J; Kaplan, David L

2017-06-27

Many potassium channel families are over-expressed in cancer, but their mechanistic role in disease progression is poorly understood. Potassium channels modulate membrane potential (Vmem) and thereby influence calcium ion dynamics and other voltage-sensitive signaling mechanisms, potentially acting as transcriptional regulators. This study investigated the differential response to over-expression and activation of a cancer-associated potassium channel, the intermediate conductance calcium-activated potassium channel (IK), on aggressive behaviors in mammary epithelial and breast cancer cell lines. IK was over-expressed in the highly metastatic breast cancer cell line MDA-MB-231 and the spontaneously immortalized breast epithelial cell line MCF-10A, and the effect on cancer-associated behaviors was assessed. IK over-expression increased primary tumor growth and metastasis of MDA-MB-231 in orthotopic xenografts, demonstrating for the first time in any cancer type that increased IK is sufficient to promote cancer aggression. The primary tumors had similar vascularization as determined by CD31 staining and similar histological characteristics. Interestingly, despite the increased in vivo growth and metastasis, neither IK over-expression nor activation with agonist had a significant effect on MDA-MB-231 proliferation, invasion, or migration in vitro. In contrast, IK decreased MCF-10A proliferation and invasion through Matrigel but had no effect on migration in a scratch-wound assay. We conclude that IK activity is sufficient to promote cell aggression in vivo. Our data provide novel evidence supporting IK and downstream signaling networks as potential targets for cancer therapies.

BRCA1/p220 loss triggers BRCA1-IRIS overexpression via mRNA stabilization in breast cancer cells

PubMed Central

Shimizu, Yoshiko; Mullins, Nicole; Blanchard, Zannel; ElShamy, Wael M.

2012-01-01

BRCA1/p220-assocaited and triple negative/basal-like (TN/BL) tumors are aggressive and incurable breast cancer diseases that share among other features the no/low BRCA1/p220 expression. Here we show that BRCA1/p220 silencing in normal human mammary epithelial (HME) cells reduces expression of two RNA-destabilizing proteins, namely AUF1 and pCBP2, both proteins bind and destabilize BRCA1-IRIS mRNA. BRCA1-IRIS overexpression in HME cells triggers expression of several TN/BL markers, e.g., cytokeratins 5 and 17, p-cadherin, EGFR and cyclin E as well as expression and activation of the pro-survival proteins; AKT and survivin. BRCA1-IRIS silencing in the TN/BL cell line, SUM149 or restoration of BRCA1/p220 expression in the mutant cell line, HCC1937 reduced expression of TN/BL markers, AKT, survivin, and induced cell death. Collectively, we propose that BRCA1/p220 loss of expression or function triggers BRCA1-IRIS overexpression through a post-transcriptional mechanism, which in turn promotes formation of aggressive and invasive breast tumors by inducing expression of TN/BL and survival proteins. PMID:22431556

BAD overexpression inhibits cell growth and induces apoptosis via mitochondrial-dependent pathway in non-small cell lung cancer.

PubMed

Jiang, Li; Luo, Man; Liu, Dan; Chen, Bojiang; Zhang, Wen; Mai, Lin; Zeng, Jing; Huang, Na; Huang, Yi; Mo, Xianming; Li, Weimin

2013-06-01

The pro-apoptotic Bcl-2 protein BAD initiated apoptosis in human cells and has been identified as a prognostic marker in non-small cell lung cancer (NSCLC). In this study, we aimed to explore the functions of BAD in NSCLC. Overexpression of BAD was performed by transfecting different NSCLC cell lines with wild-type BAD. Cell proliferation, cell cycle, apoptosis, and invasion were characterized in vitro. Tumorigenicity was analyzed in vivo. Western blot was performed to determine the effects of BAD overexpression on the Bcl-2 family proteins and apoptosis-related proteins. Overexpression of BAD significantly inhibited cell proliferation in H1299, H292, and SPC-A1 but not in SK-MES-1 and H460 cell lines in vitro. BAD overexpression also reduced the tumorigenicity of H1299/SPC-A1 cell in vivo. However, no appreciable effects on cell cycle distribution and invasion were observed in all these cell lines. BAD overexpression also induced apoptosis in all cell types, in which process expression of mitochondrial cytochrom c (cyto-c) and caspase 3 were increased, whereas Bcl-xl, Bcl-2, Bax and caspase 8 expressions did not changed. These findings indicated that a mitochondrial pathway, in which process cyto-c was released from mitochondrial to activate caspase 3, was involved in BAD overexpression-mediated apoptosis. Our data suggested that increased expression of BAD enhance apoptosis and has negative influence on cell proliferation and tumor growth in NSCLC. Bad is a new potential target for tumor interventions.

The Role of a Novel Long Noncoding RNA TUC40- in Cardiomyocyte Induction and Maturation in P19 Cells.

PubMed

Li, Huijuan; Jiang, Li; Yu, Zhangbin; Han, Shuping; Liu, Xuehua; Li, Mengmeng; Zhu, Chun; Qiao, Lixing; Huang, Li

2017-12-01

In previous studies, TUC40-, a new long noncoding RNA, was found to be overexpressed in human ventricular septal defect (VSD) embryonic heart samples. In this article, we carried out experiments on the P19 cell line to elucidate the effects of TUC40- overexpression on cardiomyocyte development relevant to VSD pathogenesis. We established the overexpression cell model by plasmid transfection, and explored the expression profile of Pbx1, the sense gene of TUC40-, and the marker genes of cardiomyocyte linage commitment (Nkx2.5 and GATA4) and maturation (cardiac troponin T). In addition, we combined cell cycle and Cell Counting Kit-8 analysis to detect cell proliferation and used flow cytometry and caspase-3 assays to test apoptosis. At last, bioinformatics analysis was performed to show the possible role of TUC40-. In the control group, Pbx1 elevated steadily during cardiomyocyte induction; whereas in the overexpression group, it showed significantly lower expression at day 6, 8 and 10 of induction. Cells in the overexpression group failed to induce cardiomyocytes indicated by GATA4 and cardiac troponin T. Proliferation was inhibited possibly owing to G2/M cell cycle arrest and the induced apoptosis rate was higher in the overexpression group. TUC40- overexpression reduced Pbx1 expression, cardiomyocyte induction and differentiation, inhibited proliferation and promoted apoptosis. Combining the results and previous studies, we propose TUC40- as a potential pathologic factor for VSD. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

Paralogous Ribosomal Protein L32-1 and L32-2 in Fission Yeast May Function Distinctively in Cellular Proliferation and Quiescence by Changing the Ratio of Rpl32 Paralogs

PubMed Central

Sun, Lei; Yang, Xiaowei; Chen, Feifei; Li, Rongpeng; Li, Xuesong; Liu, Zhenxing; Gu, Yuyu; Gong, Xiaoyan; Liu, Zhonghua; Wei, Hua; Huang, Ying; Yuan, Sheng

2013-01-01

Fission yeast cells express Rpl32-2 highly while Rpl32-1 lowly in log phase; in contrast, expression of Rpl32-1 raises and reaches a peak level while Rpl32-2 is downregulated to a low basic level when cells enter into stationary phase. Overexpression of Rpl32-1 inhibits cell growth while overexpression of Rpl32-2 does not. Deleting rpl32-2 impairs cell growth more severely than deleting rpl32-1 does. Cell growth impaired by deleting either paralog can be rescued completely by reintroducing rpl32-2, but only partly by rpl32-1. Overexpression of Rpl32-1 inhibits cell division, yielding 4c DNA and multiple septa, while overexpressed Rpl32-2 promotes it. Transcriptomics analysis proved that Rpl32 paralogs regulate expression of a subset of genes related with cell division and stress response in a distinctive way. This functional difference of the two paralogs is due to their difference of 95th amino acid residue. The significance of a competitive inhibition between Rpl32 paralogs on their expression is discussed. PMID:23577148

Enhancement in production of recombinant two-chain Insulin Glargine by over-expression of Kex2 protease in Pichia pastoris.

PubMed

Sreenivas, Suma; Krishnaiah, Sateesh M; Govindappa, Nagaraja; Basavaraju, Yogesh; Kanojia, Komal; Mallikarjun, Niveditha; Natarajan, Jayaprakash; Chatterjee, Amarnath; Sastry, Kedarnath N

2015-01-01

Glargine is an analog of Insulin currently being produced by recombinant DNA technology using two different hosts namely Escherichia coli and Pichia pastoris. Production from E. coli involves the steps of extraction of inclusion bodies by cell lysis, refolding, proteolytic cleavage and purification. In P. pastoris, a single-chain precursor with appropriate disulfide bonding is secreted to the medium. Downstream processing currently involves use of trypsin which converts the precursor into two-chain final product. The use of trypsin in the process generates additional impurities due to presence of Lys and Arg residues in the Glargine molecule. In this study, we describe an alternate approach involving over-expression of endogenous Kex2 proprotein convertase, taking advantage of dibasic amino acid sequence (Arg-Arg) at the end of B-chain of Glargine. KEX2 gene over-expression in Pichia was accomplished by using promoters of varying strengths to ensure production of greater levels of fully functional two-chain Glargine product, confirmed by HPLC and mass analysis. In conclusion, this new production process involving Kex2 protease over-expression improves the downstream process efficiency, reduces the levels of impurities generated and decreases the use of raw materials.

miR-152 regulated glioma cell proliferation and apoptosis via Runx2 mediated by DNMT1.

PubMed

Zhang, Peng; Sun, Hongwei; Yang, Bo; Luo, Wenzheng; Liu, Zengjin; Wang, Junkuan; Zuo, Yuchao

2017-08-01

Aberrant DNA methylation is associated with tumor onset and progression. Study has verified that the DNA methylation of miR-152 was mediated in many tumors, but whether it involved in glioblastomas was still unclear. This study enrolled 20 patients with glioma to analyze the expression pattern of miR-152. Real-time PCR and western blot were used to detect the mRNA or protein expression level, respectively. The relationship between miR-152 and runx2 was detected by Luciferase reporter assay. The methylation level of miR-152 was determined by methylation-specific PCR. Cell proliferation and apoptosis were detected by MTT and Annexin-FITC/PI assay. The expression of miR-152 was down-regulated while the expression of DNMT1 was up-regulated in both glioma tissue and cell lines. MiR-152 was hypermethylated and its expression was negatively correlated with DNMT in glioma cell lines. DNMT1 knockdown promoted the expression of miR-152, however, DNMT1 overexpression suppressed the expression of miR-152. MiR-152 overexpression promoted glioma cell apoptosis while miR-152 knockdown promoted cell proliferation. MiR-152 targets Runx2 to regulate its expression, Runx2 overexpression abolished the effects of miR-152 overexpression. MiR-152 regulated cell proliferation and apoptosis of glioma mediated by Runx2, while the mechanism of down regulated miR-152 in glioma tissues and cells was its hypermethylation. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Constitutive expression of a grapevine polygalacturonase-inhibiting protein affects gene expression and cell wall properties in uninfected tobacco

PubMed Central

2011-01-01

Background Polygalacturonase-inhibiting proteins (PGIPs) directly limit the effective ingress of fungal pathogens by inhibiting cell wall-degrading endopolygalacturonases (ePGs). Transgenic tobacco plants over-expressing grapevine (Vitis vinifera) Vvpgip1 have previously been shown to be resistant to Botrytis infection. In this study we characterized two of these PGIP over-expressing lines with known resistance phenotypes by gene expression and hormone profiling in the absence of pathogen infection. Results Global gene expression was performed by a cross-species microarray approach using a potato cDNA microarray. The degree of potential cross-hybridization between probes was modeled by a novel computational workflow designed in-house. Probe annotations were updated by predicting probe-to-transcript hybridizations and combining information derived from other plant species. Comparing uninfected Vvpgip1-overexpressing lines to wild-type (WT), 318 probes showed significant change in expression. Functional groups of genes involved in metabolism and associated to the cell wall were identified and consequent cell wall analysis revealed increased lignin-levels in the transgenic lines, but no major differences in cell wall-derived polysaccharides. GO enrichment analysis also identified genes responsive to auxin, which was supported by elevated indole-acetic acid (IAA) levels in the transgenic lines. Finally, a down-regulation of xyloglucan endotransglycosylase/hydrolases (XTHs), which are important in cell wall remodeling, was linked to a decrease in total XTH activity. Conclusions This evaluation of PGIP over-expressing plants performed under pathogen-free conditions to exclude the classical PGIP-ePG inhibition interaction indicates additional roles for PGIPs beyond the inhibition of ePGs. PMID:22078230

Overexpression of Prox1 Induces the Differentiation of Human Adipose-Derived Stem Cells into Lymphatic Endothelial-Like Cells In Vitro.

PubMed

Deng, Jingcheng; Dai, Tingting; Sun, Yiyu; Zhang, Qi; Jiang, Zhaohua; Li, Shengli; Cao, Weigang

2017-02-01

Constant levels of homeobox transcription factor Prox1 expression are required throughout the life of lymphatic endothelial cells (LECs) to maintain their differentiated identity. Recent studies have demonstrated that using human LECs for cell transplantation therapy may improve secondary lymphedema in a nude rat model. However, the application is currently limited by the low yield of LECs. In this study, Prox1 was overexpressed in human adipose tissue-derived stem cells (hADSCs) by using the transfection of lentiviral vectors to induce the differentiation of hADSCs to LECs. After 14 days of Prox1 overexpression, flow cytometry analysis found that the expression of LEC-specific markers such as Podoplanin and VEGFR3, along with the endothelial cell (EC) marker CD31, on Prox1-overexpressed hADSCs was significantly increased; however, the expression of mesenchymal stem cell markers, such as CD29, CD44, and CD90, was substantially reduced. In addition, the mRNA levels of the LEC-specific markers, such as Prox1, Podoplanin, LYVE1, and VEGFR3, in Prox1-overexpressed hADSCs were significantly increased at day 7 and maintained a continuously increased expression level for 28 observation days, according to real-time reverse transcriptase-polymerase chain reaction results. Western blotting and immunofluorescence staining results further confirmed that overexpression of Prox1 in hADSCs significantly increased the protein levels of Podoplanin, LYVE1, and VEGFR3, as well as those of the EC markers such as VWF and CD144, at day 14. Moreover, these differentiated cells were found to form tube-like structures in matrigel, measured by the tube formation assay. These findings suggested that overexpression of Prox1 in hADSCs successfully induced the differentiation of hADSCs into stable lymphatic endothelial-like cells. This study achieved a long-lasting expression of Prox1 in lymphatic endothelial-like cells, and it provided a potentially useful approach for developing novel therapies for limb lymphedema and lymphatic system-related diseases.

EpCAM overexpression prolongs proliferative capacity of primary human breast epithelial cells and supports hyperplastic growth

PubMed Central

2013-01-01

Introduction The Epithelial Cell Adhesion Molecule (EpCAM) has been shown to be strongly expressed in human breast cancer and cancer stem cells and its overexpression has been supposed to support tumor progression and metastasis. However, effects of EpCAM overexpression on normal breast epithelial cells have never been studied before. Therefore, we analyzed effects of transient adenoviral overexpression of EpCAM on proliferation, migration and differentiation of primary human mammary epithelial cells (HMECs). Methods HMECs were transfected by an adenoviral system for transient overexpression of EpCAM. Thereafter, changes in cell proliferation and migration were studied using a real time measurement system. Target gene expression was evaluated by transcriptome analysis in proliferating and polarized HMEC cultures. A Chicken Chorioallantoic Membrane (CAM) xenograft model was used to study effects on in vivo growth of HMECs. Results EpCAM overexpression in HMECs did not significantly alter gene expression profile of proliferating or growth arrested cells. Proliferating HMECs displayed predominantly glycosylated EpCAM isoforms and were inhibited in cell proliferation and migration by upregulation of p27KIP1 and p53. HMECs with overexpression of EpCAM showed a down regulation of E-cadherin. Moreover, cells were more resistant to TGF-β1 induced growth arrest and maintained longer capacities to proliferate in vitro. EpCAM overexpressing HMECs xenografts in chicken embryos showed hyperplastic growth, lack of lumen formation and increased infiltrates of the chicken leukocytes. Conclusions EpCAM revealed oncogenic features in normal human breast cells by inducing resistance to TGF-β1-mediated growth arrest and supporting a cell phenotype with longer proliferative capacities in vitro. EpCAM overexpression resulted in hyperplastic growth in vivo. Thus, we suggest that EpCAM acts as a prosurvival factor counteracting terminal differentiation processes in normal mammary glands. PMID:23758908

Overexpression of B7-H3 augments anti-apoptosis of colorectal cancer cells by Jak2-STAT3.

PubMed

Zhang, Ting; Jiang, Bo; Zou, Shi-Tao; Liu, Fen; Hua, Dong

2015-02-14

To investigate the role of the overexpression of B7-H3 in apoptosis in colorectal cancer cell lines and the underlying molecular mechanisms. SW620 cells that highly overexpressed B7-H3 (SW620-B7-H3-EGFP) and HCT8 cells stably transfected with B7-H3 shRNA (HCT8-shB7-H3) were previously constructed in our laboratory. Cells transfected with pIRES2-EGFP were used as negative controls (SW620-NC and HCT8-NC). Real-time PCR and western blotting analysis were used to detect the mRNA and protein expressions of the apoptosis regulator proteins Bcl-2, Bcl-xl and Bax. A cell proliferation assay was used to evaluate the survival rate and drug sensitivity of the cells. The effect of drug resistance was detected by a cell cycle assay. Active caspase-3 western blotting was used to reflect the anti-apoptotic ability of cells. Western blotting was also performed to determine the expression of proteins associated with the Jak2-STAT3 signaling pathway and the apoptosis regulator proteins after the treatment with AG490, a Jak2 specific inhibitor, in B7-H3 overexpressing cells. The data were analyzed by GraphPad Prism 6 using a non-paired t-test. Whether by overexpression in SW620 cells or downregulation in HCT8, B7-H3 significantly affected the expression of anti- and pro-apoptotic proteins, at both the transcriptional and translational levels, compared with the negative control (P < 0.05). A cell proliferation assay revealed that B7-H3 overexpression increased the drug resistance of cells and resulted in a higher survival rate (P < 0.05). In addition, the results of cell cycle and active caspase-3 western blotting proved that B7-H3 overexpression inhibited apoptosis in colorectal cancer cell lines (P < 0.05). B7-H3 overexpression improved Jak2 and STAT3 phosphorylation and, in turn, increased the expression of the downstream anti-apoptotic proteins B-cell CLL/lymphoma 2 (Bcl-2) and Bcl-xl, based on western blotting (P < 0.05). After treating B7-H3 overexpressing cells with the Jak2-specific inhibitor AG490, the phosphorylation of Jak2 and STAT3, and the expression of Bcl-2 and Bcl-xl, decreased accordingly (P < 0.05). This finding suggested that the Jak2-STAT3 pathway is involved in the mechanism mediating the anti-apoptotic ability of B7-H3. The overexpression of B7-H3 induces resistance to apoptosis in colorectal cancer cell lines by upregulating the Jak2-STAT3 signaling pathway, potentially providing new approaches to the treatment of colorectal cancer.

Bromodomain proteins GTE9 and GTE11 are essential for specific BT2-mediated sugar and ABA responses in Arabidopsis thaliana.

PubMed

Misra, Anjali; McKnight, Thomas D; Mandadi, Kranthi K

2018-03-01

Global Transcription Factor Group E proteins GTE9 and GTE11 interact with BT2 to mediate ABA and sugar responses in Arabidopsis thaliana. BT2 is a BTB-domain protein that regulates responses to various hormone, stress and metabolic conditions in Arabidopsis thaliana. Loss of BT2 results in plants that are hypersensitive to inhibition of germination by abscisic acid (ABA) and sugars. Conversely, overexpression of BT2 results in resistance to ABA and sugars. Here, we report the roles of BT2-interacting partners GTE9 and GTE11, bromodomain and extraterminal-domain proteins of Global Transcription Factor Group E, in BT2-mediated responses to sugars and hormones. Loss-of-function mutants, gte9-1 and gte11-1, mimicked the bt2-1-null mutant responses; germination of all three mutants was hypersensitive to inhibition by glucose and ABA. Loss of either GTE9 or GTE11 in a BT2 over-expressing line blocked resistance to sugars and ABA, indicating that both GTE9 and GTE11 were required for BT2 function. Co-immunoprecipitation of BT2 and GTE9 suggested that these proteins physically interact in vivo, and presumably function together to mediate responses to ABA and sugar signals.

Effect of trichostatin A on Burkitt's lymphoma cells: Inhibition of EPS8 activity through Phospho-Erk1/2 pathway.

PubMed

Sun, Peipei; Zhou, Xin; He, Yingzhi; Liu, Huimin; Wang, Yuxin; Chen, Yiran; Li, Meifang; He, Yanjie; Li, Guowei; Li, Yuhua

2018-03-18

Histone deacetylase inhibitors (HDACi) manifest great potential for treatment of Burkitt's lymphoma (BL), an aggressive B-cell lymphoma. Epidermal growth factor receptor pathway substrate 8 (EPS8) is confirmed overexpressed and associated with poor prognosis in solid tumors and leukemia. However, EPS8 expression and the relationship between EPS8 and HDACi on BL remains obscure. Here, we hypothesized that trichostatin A (TSA), a pan-HDACi, could inhibit BL cells by downregulating EPS8. We demonstrated that TSA reduced cell viability, induced apoptosis and cell arrest at G0/G1. Mechanismly, TSA attenuated EPS8 and downstream Phospho-Erk1/2 pathway. Knockdown of EPS8 resulted in a significant reduction in cellular proliferation and suppressed Phospho-Erk1/2 pathway activity, particularly when combined with TSA. Conversely, overexpression of EPS8 rescued this phenomenon. Then we showed that the combination of TSA and Epirubicin had a more significant effect when compared with TSA or Epirubicin alone. Finally, knockdown of EPS8 and TSA had a synergistic suppression effect on BALB/c nude mice. In conclusion, this study reveals that TSA affects BL cells by suppressing Phospho-Erk1/2 pathway through downregulating EPS8. Copyright © 2018 Elsevier Inc. All rights reserved.

The role of spartin and its novel ubiquitin binding region in DALIS occurrence

PubMed Central

Karlsson, Amelia B.; Washington, Jacqueline; Dimitrova, Valentina; Hooper, Christopher; Shekhtman, Alexander; Bakowska, Joanna C.

2014-01-01

Troyer syndrome is an autosomal recessive hereditary spastic paraplegia (HSP) caused by frameshift mutations in the SPG20 gene that results in a lack of expression of the truncated protein. Spartin is a multifunctional protein, yet only two conserved domains—a microtubule-interacting and trafficking domain and a plant-related senescence domain involved in cytokinesis and mitochondrial physiology, respectively—have been defined. We have shown that overexpressed spartin binds to the Ile44 hydrophobic pocket of ubiquitin, suggesting spartin might contain a ubiquitin-binding domain. In the present study, we demonstrate that spartin contributes to the formation of dendritic aggresome-like induced structures (DALIS) through a unique ubiquitin-binding region (UBR). Using short hairpin RNA, we knocked down spartin in RAW264.7 cells and found that DALIS frequency decreased; conversely, overexpression of spartin increased the percentage of cells containing DALIS. Using nuclear magnetic resonance spectroscopy, we characterized spartin's UBR and defined the UBR's amino acids that are key for ubiquitin binding. We also found that spartin, via the UBR, binds Lys-63–linked ubiquitin chains but does not bind Lys-48–linked ubiquitin chains. Finally, we demonstrate that spartin's role in DALIS formation depends on key residues within its UBR. PMID:24523286

Positive prognostic value of HER2-HER3 co-expression and p-mTOR in gastric cancer patients.

PubMed

Cao, Guo-Dong; Chen, Ke; Chen, Bo; Xiong, Mao-Ming

2017-12-12

The HER2-HER3 heterodimer significantly decreases survival in breast cancer patients. However, the prognostic value of HER2-HER3 overexpression remains unknown in gastric cancer (GC). The expression levels of HER2, HER3, Akt, p-Akt, mTOR and p-mTOR were examined in specimens from 120 GC patients by immunohistochemistry and quantitative reverse transcription-PCR. The associations of HER proteins, PI3K/Akt/mTOR pathway-related proteins, clinicopathological features of GC, and overall survival (OS) were assessed. To comprehensively evaluate the prognostic values of pathway-related proteins, meta-analyses were conducted with STATA 11.0. HER2 overexpression was significantly associated with HER3 levels (P = 0.02). HER3 was highly expressed in gastric cancer tissues. High HER2 and HER3 levels were associated with elevated p-Akt and p-mTOR amounts (P < 0.05). Furthermore, HER2-HER3 co-expression was associated with high p-Akt and p-mTOR (P < 0.05) levels. Meanwhile, p-mTOR overexpression was tightly associated with differentiation, depth of invasion, lymph node metastasis, TNM stage and OS (P < 0.05). By meta-analyses, Akt, p-Akt, and mTOR levels were unrelated to clinicopathological characters. HER3 overexpression was associated with depth of invasion (OR = 2.39, 95%CI 1.62-3.54, P < 0.001) and lymph node metastasis (OR = 2.35, 95%CI 1.34-4.11, P = 0.003). Further, p-mTOR overexpression was associated with patient age, tumor location, depth of invasion (OR = 1.63, 95%CI 1.08-2.45, P = 0.02) and TNM stage (OR = 1.73, 95%CI 1.29-2.32, P < 0.001). In addition, HER2-HER3 overexpression corresponded to gradually shortened 5-year OS (P < 0.05), and significant relationships were shown among HER3, p-mTOR overexpression, and 1-, 3-, 5-year OS (P < 0.05). HER2-HER3 co-expression may potentially enhance mTOR phosphorylation. HER2-HER3 co-expression and p-mTOR are both related to the prognosis of GC patients.

Elevated levels of p-Mnk1, p-eIF4E and p-p70S6K proteins are associated with tumor recurrence and poor prognosis in astrocytomas.

PubMed

Fan, Weibing; Wang, Weiyuan; Mao, Xinfa; Chu, Shuzhou; Feng, Juan; Xiao, Desheng; Zhou, Jianhua; Fan, Songqing

2017-02-01

Malignant astrocytomas are able to invade neighboring and distant areas of the normal brain. Signaling pathway alterations play important role in the development of astrocytomas. Deregulation of eukaryotic translation initiation factor 4E (eIF4E) by MAP kinase-interacting kinases (Mnk) on Ser-209 directly or PI3K/mTOR/S6K pathway indirectly has a critical effect on promoting cellular proliferation, malignant transformation and metastasis. We examined and analyzed the correlation between expression of p-Mnk1, p-eIF4E and p-p70S6K proteins and clinicopathological features in 103 astrocytomas and 54 non-tumorous brain tissues. The results indicated that positive percentage of overexpression of p-Mnk1 and p-eIF4E proteins in astrocytomas were significantly higher than that of in the non-tumorous brain tissues (P < 0.05). Elevated p-Mnk1 and p-eIF4E and co-overexpressed three proteins were associated with tumor recurrence (P = 0.003, P = 0.006, P = 0.007, respectively). Overexpressed p-eIF4E significantly correlated with the tumor size (P = 0.019). In addition, overexpression of p-eIF4E and three proteins common expression were related to the WHO grade of astrocytomas (P = 0.001, P = 0.044 respectively). Spearman's rank correlation test further showed that the expression of p-Mnk1 was strongly positive correlated with the expression of p-eIF4E in astrocytomas (r = 0.294, P = 0.003). Besides, overexpression of p-eIF4E and co-expression of p-Mnk1, p-eIF4E and p-p70S6K proteins were inversely correlated with overall survival rates of astrocytomas. Multivariate Cox regression analysis further identified that the elevated p-eIF4E expression, three proteins common expression were correlated with unfavorable prognosis of astrocytomas regardless of ages and WHO grades. Taken together, overexpression of p-eIF4E and co-expression of p-Mnk1, p-eIF4E and p-p70S6K proteins could be used as novel independent poor prognostic biomarkers for patients with astrocytomas.

Identification of a regulatory T cell specific cell surface molecule that mediates suppressive signals and induces Foxp3 expression.

PubMed

Wang, Rui; Wan, Qi; Kozhaya, Lina; Fujii, Hodaka; Unutmaz, Derya

2008-07-16

Regulatory T (T(reg)) cells control immune activation and maintain tolerance. How T(regs) mediate their suppressive function is unclear. Here we identified a cell surface molecule, called GARP, (or LRRC32), which within T cells is specifically expressed in T(regs) activated through the T cell receptor (TCR). Ectopic expression of GARP in human naïve T (T(N)) cells inhibited their proliferation and cytokine secretion upon TCR activation. Remarkably, GARP over-expression in T(N) cells induced expression of T(reg) master transcription factor Foxp3 and endowed them with a partial suppressive function. The extracellular but not the cytoplasmic region of GARP, was necessary for these functions. Silencing Foxp3 in human T(reg) cells reduced expression of GARP and attenuated their suppressive function. However, GARP function was not affected when Foxp3 was downregulated in GARP-overexpressing cells, while silencing GARP in Foxp3-overexpressing cells reduced their suppressive activity. These findings reveal a novel cell surface molecule-mediated regulatory mechanism, with implications for modulating aberrant immune responses.

[Design of new anti-tumor agents interrupting deregulated signaling pathways induced by tyrosine kinase proteins. Inhibition of protein-protein interaction involving Grb2].

PubMed

Vidal, Michel; Liu, Wang Qing; Gril, Brunile; Assayag, Franck; Poupon, Marie-France; Garbay, Christiane

2004-01-01

Cellular signaling pathways induced by growth-factor receptors are frequently deregulated in cancer. Anti-tumor agents that inhibit their enzymatic tyrosine kinase activity have been designed and are now used in human chemotherapy. We propose here an alternative way to interrupt over-expressed signaling by inhibiting protein-protein interactions that involve either the over-expressed proteins or proteins located downstream. The adaptor protein Grb2 over-expressed in connection with HER2/ErbB2/neu in Ras signaling pathway was chosen as a target. Peptides with very high affinity for Grb2 were rationally designed from structural data. Their capacity to interrupt the signaling pathway, their anti-proliferative activity as well as their potential anti-tumor properties are described.

Concurrent nuclear ERG and MYC protein overexpression defines a subset of locally advanced prostate cancer: Potential opportunities for synergistic targeted therapeutics.

PubMed

Udager, Aaron M; DeMarzo, Angelo M; Shi, Yang; Hicks, Jessica L; Cao, Xuhong; Siddiqui, Javed; Jiang, Hui; Chinnaiyan, Arul M; Mehra, Rohit

2016-06-01

Recurrent ERG gene fusions, the most common genetic alterations in prostate cancer, drive overexpression of the nuclear transcription factor ERG, and are early clonal events in prostate cancer progression. The nuclear transcription factor MYC is also frequently overexpressed in prostate cancer and may play a role in tumor initiation and/or progression. The relationship between nuclear ERG and MYC protein overexpression in prostate cancer, as well as the clinicopathologic characteristics and prognosis of ERG-positive/MYC high tumors, is not well understood. Immunohistochemistry (IHC) for ERG and MYC was performed on formalin-fixed, paraffin-embedded tissue from prostate cancer tissue microarrays (TMAs), and nuclear staining was scored semi-quantitatively (IHC product score range = 0-300). Correlation between nuclear ERG and MYC protein expression and association with clinicopathologic parameters and biochemical recurrence after radical prostatectomy was assessed. 29.1% of all tumor nodules showed concurrent nuclear ERG and MYC protein overexpression (i.e., ERG-positive/MYC high), including 35.0% of secondary nodules. Overall, there was weak positive correlation between ERG and MYC expression across all tumor nodules (rpb  = 0.149, P = 0.045), although this correlation was strongest in secondary nodules (rpb  = 0.520, P = 0.019). In radical prostatectomy specimens, ERG-positive/MYC high tumors were positively associated with the presence of extraprostatic extension (EPE), relative to all other ERG/MYC expression subgroups, however, there was no significant association between concurrent nuclear ERG and MYC protein overexpression and time to biochemical recurrence. Concurrent nuclear ERG and MYC protein overexpression is common in prostate cancer and defines a subset of locally advanced tumors. Recent data indicates that BET bromodomain proteins regulate ERG gene fusion and MYC gene expression in prostate cancer, suggesting possible synergistic targeted therapeutics in ERG-positive/MYC high tumors. Prostate 76:845-853, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

MiR-328 suppresses the survival of esophageal cancer cells by targeting PLCE1

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

Han, Na; Zhao, Wenchao; Zhang, Zhongmian

2016-01-29

Esophageal cancer (EC) is the sixth leading cause of death worldwide. Recent studies have highlighted the vital role of microRNAs (miRNAs) in EC development and diagnosis. In our study, qPCR analysis showed that miRNA-328 was expressed at significantly low levels in EC109 and EC9706 cells. The results also showed that overexpression of miR-328 by lentivirus-mediated gene transfer markedly inhibited cell proliferation and invasion, and enhanced apoptosis; whereas, inhibition of miR-328 significantly promoted cell proliferation and invasion, and suppressed apoptosis in EC109 and EC9706 cells. Dual-luciferase reporter assay confirmed that miR-328 directly targeted phospholipase C epsilon 1 (PLCE1) by binding to target sequencesmore » in the 3′-UTR. qPCR and Western blot analysis showed that the PLCE1 was overexpressed in EC109 and EC9706 cells. Additionally, we found that miR-328 overexpression decreased PLCE1 mRNA and protein levels, while miR-328 inhibition enhanced the PLCE1 expression. Further analysis showed that PLCE1 overexpression rescued the inhibitory effect of miR-328 on cell proliferation and invasion, and repressed the promotive effect of miR-328 on cell apoptosis. In conclusion, our results suggest that miR-328 suppresses the survival of EC cells by regulating PLCE1 expression, which might be a potential therapeutic method for EC. - Highlights: • PLCE1 was a target gene of miR-328. • MiR-328 overexpression decreased PLCE1 expression. • PLCE1 overexpression rescued the inhibitory effect of miR-328 on the survival of EC cells.« less

Osteoblast proliferation is enhanced upon the insulin receptor substrate 1 overexpression via PI3K signaling leading to down-regulation of NFκB and BAX pathway.

PubMed

Ma, H; Ma, J X; Xue, P; Gao, Y; Li, Y K

2015-02-01

The insulin receptor substrate 1 (IRS1) promotes bone formation via osteoblast proliferation mediated by PI3K/Akt signaling. A reduction in NFκB activity in osteoblasts results in an increase in bone formation. The NFκB signaling pathway leads to increased expression of BAX, which contributes to osteoblast apoptosis. The purpose of this study was to investigate the expression of recombinant plasmid enhanced green fluorescent protein-N1 (pEGFP-N1) that transferred IRS1 gene into osteoblasts in vitro and evaluate the effects of IRS1 overexpression on NFκBp65 and on BAX. Osteoblasts were transfected with pEGFP-N1 or pEGFP-N1 encoding wild-type IRS1 (pEGFP-N1-IRS1). Cell cycle analysis was performed using flow cytometry. The expression levels of NFκBp65 and BAX were measured by Western blotting. Our results revealed that overexpression of IRS1 stimulated osteoblast proliferation, as evidenced by an increase in the number of cells in the S phase compared to controls. IRS1 overexpression in osteoblasts activated the PI3K/Akt pathway, and inhibited expression of NFκBp65 and BAX. When osteoblasts transfected with pEGFP-N1-IRS1 were exposed to a PI3K inhibitor (LY294002), the effects of IRS1 overexpression were reversed. On the basis of our study, it seems that osteoblasts proliferated upon IRS1 overexpression due to inhibition of the NFκB pathway and downregulation of BAX through PI3K/Akt signaling. © Georg Thieme Verlag KG Stuttgart · New York.

MicroRNA-194 promotes osteoblast differentiation via downregulating STAT1

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

Li, Jun; He, Xijing; Wei, Wenzhi

Osteoblast differentiation is a vital process in maintaining bone homeostasis in which various transcriptional factors, signaling molecules, and microRNAs (miRNAs) are involved. Recently, signal transducer and activator of transcription 1 (STAT1) has been found to play an important role in regulating osteoblast differentiation. Here, we identified that STAT1 expression was regulated by miR-194. Using mouse bone mesenchymal stem cells (BMSCs), we found that miR-194 expression was significantly increased following osteoblast differentiation induction. Overexpression of miR-194 by lentivirus-mediated gene transfer markedly increased osteoblast differentiation, whereas inhibition of miR-194 significantly suppressed osteoblast differentiation of BMSCs. Using a dual-luciferase reporter assay, a directmore » interaction between miR-194 and the 3′-untranslated region (UTR) of STAT1 was confirmed. Additionally, miR-194 regulated mRNA and protein expression of STAT1 in BMSCs. Further analysis showed that miR-194 overexpression promoted the nuclear translocation of runt-related transcription factor 2 (Runx2), which is critical for osteoblast differentiation. In contrast, inhibition of miR-194 blocked the nuclear translocation of Runx2. Moreover, overexpression of STAT1 significantly blocked Runx2 nuclear translocation and osteoblast differentiation mediated by miR-194 overexpression. Taken together, our data suggest that miR-194 regulates osteoblast differentiation through modulating STAT1-mediated Runx2 nuclear translocation. - Highlights: • Overexpression of miR-194 significantly increased osteoblast differentiation. • miR-194 directly targeted the 3′- UTR of STAT1. • miR-194 regulated the expression of STAT1. • Overexpression of miR-194 promoted the nuclear translocation of Runx2.« less

S100A4 is frequently overexpressed in lung cancer cells and promotes cell growth and cell motility

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

Chen, Na; Sato, Daisuke; Saiki, Yuriko

2014-05-09

Highlights: • We observed frequent overexpression of S100A4 in lung cancer cell lines. • Knockdown of S100A4 suppressed proliferation in lung cancer cells. • Forced expression of S100A4 accelerated cell motility in lung cancer cells. • PRDM2 was found to be one of the downstream suppressed genes of S100A4. - Abstract: S100A4, a small calcium-binding protein belonging to the S100 protein family, is commonly overexpressed in a variety of tumor types and is widely accepted to associate with metastasis by regulating the motility and invasiveness of cancer cells. However, its biological role in lung carcinogenesis is largely unknown. In thismore » study, we found that S100A4 was frequently overexpressed in lung cancer cells, irrespective of histological subtype. Then we performed knockdown and forced expression of S100A4 in lung cancer cell lines and found that specific knockdown of S100A4 effectively suppressed cell proliferation only in lung cancer cells with S100A4-overexpression; forced expression of S100A4 accelerated cell motility only in S100A4 low-expressing lung cancer cells. PRDM2 and VASH1, identified as novel upregulated genes by microarray after specific knockdown of S100A4 in pancreatic cancer, were also analyzed, and we found that PRDM2 was significantly upregulated after S100A4-knockdown in one of two analyzed S100A4-overexpressing lung cancer cells. Our present results suggest that S100A4 plays an important role in lung carcinogenesis by means of cell proliferation and motility by a pathway similar to that in pancreatic cancer.« less

Enhanced xylose fermentation by engineered yeast expressing NADH oxidase through high cell density inoculums.

PubMed

Zhang, Guo-Chang; Turner, Timothy L; Jin, Yong-Su

2017-03-01

Accumulation of reduced byproducts such as glycerol and xylitol during xylose fermentation by engineered Saccharomyces cerevisiae hampers the economic production of biofuels and chemicals from cellulosic hydrolysates. In particular, engineered S. cerevisiae expressing NADPH-linked xylose reductase (XR) and NAD + -linked xylitol dehydrogenase (XDH) produces substantial amounts of the reduced byproducts under anaerobic conditions due to the cofactor difference of XR and XDH. While the additional expression of a water-forming NADH oxidase (NoxE) from Lactococcus lactis in engineered S. cerevisiae with the XR/XDH pathway led to reduced glycerol and xylitol production and increased ethanol yields from xylose, volumetric ethanol productivities by the engineered yeast decreased because of growth defects from the overexpression of noxE. In this study, we introduced noxE into an engineered yeast strain (SR8) exhibiting near-optimal xylose fermentation capacity. To overcome the growth defect caused by the overexpression of noxE, we used a high cell density inoculum for xylose fermentation by the SR8 expressing noxE. The resulting strain, SR8N, not only showed a higher ethanol yield and lower byproduct yields, but also exhibited a high ethanol productivity during xylose fermentation. As noxE overexpression elicits a negligible growth defect on glucose conditions, the beneficial effects of noxE overexpression were substantial when a mixture of glucose and xylose was used. Consumption of glucose led to rapid cell growth and therefore enhanced the subsequent xylose fermentation. As a result, the SR8N strain produced more ethanol and fewer byproducts from a mixture of glucose and xylose than the parental SR8 strain without noxE overexpression. Our results suggest that the growth defects from noxE overexpression can be overcome in the case of fermenting lignocellulose-derived sugars such as glucose and xylose.

The intratumoral balance between metabolic and immunologic gene expression is associated with anti-PD-1 response in patients with renal cell carcinoma

PubMed Central

Ascierto, Maria Libera; McMiller, Tracee L.; Berger, Alan E.; Danilova, Ludmila; Anders, Robert A.; Netto, George J.; Xu, Haiying; Pritchard, Theresa S.; Fan, Jinshui; Cheadle, Chris; Cope, Leslie; Drake, Charles G.; Pardoll, Drew M.; Taube, Janis M.; Topalian, Suzanne L.

2016-01-01

Pretreatment tumor PD-L1 expression correlates with response to anti-PD-1/PD-L1 therapies. Yet, most patients with PD-L1+ tumors do not respond to treatment. The current study was undertaken to investigate mechanisms underlying the failure of PD-1–targeted therapies in patients with advanced renal cell carcinoma (RCC) whose tumors express PD-L1. Formalin-fixed, paraffin-embedded (FFPE) pretreatment tumor biopsies expressing PD-L1 were derived from 13 RCC patients. RNA was isolated from PD-L1+ regions and subjected to whole genome microarray and multiplex quantitative (q)RT-PCR gene expression analysis. A balance between gene expression profiles reflecting metabolic pathways and immune functions was associated with clinical outcomes following anti-PD-1 therapy. In particular, the expression of genes involved in metabolic and solute transport functions such as UGT1A family members, also found in kidney cancer cell lines, was associated with treatment failure in patients with PD-L1+ RCC. Conversely, tumors from responding patients overexpressed immune markers such as BACH2, a regulator of CD4+ T cell differentiation, and CCL3, involved in leukocyte migration. These findings suggest that tumor cell–intrinsic metabolic factors may contribute to treatment resistance in RCC, thus serving as predictive markers for treatment outcomes and potential new targets for combination therapy regimens with anti-PD-1. PMID:27491898

Kruppel-like factor 2 inhibits hypoxia-inducible factor 1alpha expression and function in the endothelium.

PubMed

Kawanami, Daiji; Mahabeleshwar, Ganapati H; Lin, Zhiyong; Atkins, G Brandon; Hamik, Anne; Haldar, Saptarsi M; Maemura, Koji; Lamanna, Joseph C; Jain, Mukesh K

2009-07-31

Hypoxia-inducible factor 1 (HIF-1) is a central regulator of the hypoxic response in many cell types. In endothelial cells, HIF-1 induces the expression of key proangiogenic factors to promote angiogenesis. Recent studies have identified Kruppel-like factor 2 (KLF2) as a potent inhibitor of angiogenesis. However, the role of KLF2 in regulating HIF-1 expression and function has not been evaluated. KLF2 expression was induced acutely by hypoxia in endothelial cells. Adenoviral overexpression of KLF2 inhibited hypoxia-induced expression of HIF-1alpha and its target genes such as interleukin 8, angiopoietin-2, and vascular endothelial growth factor in endothelial cells. Conversely, knockdown of KLF2 increased expression of HIF-1alpha and its targets. Furthermore, KLF2 inhibited hypoxia-induced endothelial tube formation, whereas endothelial cells from mice with haploinsufficiency of KLF2 showed increased tube formation in response to hypoxia. Consistent with this ex vivo observation, KLF2 heterozygous mice showed increased microvessel density in the brain. Mechanistically, KLF2 promoted HIF-1alpha degradation in a von Hippel-Lindau protein-independent but proteasome-dependent manner. Finally, KLF2 disrupted the interaction between HIF-1alpha and its chaperone Hsp90, suggesting that KLF2 promotes degradation of HIF-1alpha by affecting its folding and maturation. These observations identify KLF2 as a novel inhibitor of HIF-1alpha expression and function. Therefore, KLF2 may be a target for modulating the angiogenic response in disease states.

Gene expression analysis of the SdeAB multidrug efflux pump in antibiotic-resistant clinical isolates of Serratia marcescens.

PubMed

Dalvi, S D; Worobec, E A

2012-01-01

Many isolates of Serratia marcescens, a well-known opportunistic pathogen, can be multidrug resistant. Fluoroquinolones are among the most important groups of antibiotics used for treatment of these organisms. However, fluoroquinolone resistance among S. marcescens isolates is fast increasing. Drug extrusion through efflux pumps like SdeAB/ HasF is one of the major mechanisms of resistance to fluoroquinolones. This study was carried out to analyze, through gene expression analysis of sdeB, the relative contribution of this mechanism toward fluoroquinolone resistance in clinical isolates of Serratia. Total RNA from 45 clinical isolates of S. marcescens was isolated. Quantitative real-time RT PCR was performed on the extracted RNA to study the gene expression of sdeB and was normalized to the sdeB expression in the standard strain of S. marcescens. Of the 45 isolates analyzed, sdeB expression was found to be elevated in 20 isolates (44%). Of these 20 isolates, eight (40%) were fully resistant to at least one of the fluoroquinolones studied. Conversely, of the 20 isolates that over-expressed sdeB, 12 (60%) were fully sensitive to all fluoroquinolones tested. Drug efflux pumps are an important means of fluoroquinolone resistance among clinically important species of Serratia. The expression of these pumps can be up-regulated in the presence of antibiotics and have the potential for changing the phenotype from sensitive to resistant, thus contributing to therapeutic failures.