The histone variant H2A.X is a regulator of EpithelialâMesenchymal Transition
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: E-GEOD-75444 | BioStudies |
REPOSITORIES: biostudies
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Project description:The epithelial-mesenchymal transition (EMT), considered essential for metastatic cancer, has been a focus of much research, but important questions remain. Here, we show that silencing or removing H2A.X, a histone H2A variant involved in cellular DNA repair and robust growth, induces mesenchymal-like characteristics including activation of EMT transcription factors, Slug and ZEB1, in HCT116 human colon cancer cells. Ectopic H2A.X re-expression partially reverses these changes, as does silencing Slug and ZEB1. In an experimental metastasis model, the HCT116 parental and H2A.X-null cells exhibit a similar metastatic behaviour, but the cells with re-expressed H2A.X are substantially more metastatic. We surmise that H2A.X re-expression leads to partial EMT reversal and increases robustness in the HCT116 cells, permitting them to both form tumours and to metastasize. In a human adenocarcinoma panel, H2A.X levels correlate inversely with Slug and ZEB1 levels. Together, these results point to H2A.X as a regulator of EMT.
| S-EPMC4756313 | BioStudies
Project description:The epithelial-mesenchymal transition (EMT), considered essential for metastatic cancer, has been a focus of much research, but important questions remain. Here, we show that silencing or removing H2A.X, a histone H2A variant involved in cellular DNA repair and robust growth, induced mesenchymal-like characteristics including activation of EMT transcription factors, Slug and ZEB1, in HCT116 human colon cancer cells. Ectopic H2A.X re-expression partially reversed these changes; as did silencing Slug and ZEB1. In an experimental metastasis model, the HCT116 parental and H2A.X-null cells exhibited similar metastases levels, but the cells with re-expressed H2A.X exhibited substantially elevated levels. We surmise that H2A.X re-expression led to partial EMT reversal and increased robustness in the HCT116 cells, permitting them to both form tumors and to metastasize. In a human adenocarcinoma panel, H2A.X levels correlated inversely with Slug and ZEB1 levels. Together, these results point to H2A.X as a novel regulator of EMT. Overall design: 9 samples in total including 4 replicates of control shRNA and 5 replicates of shH2A.X.
| GSE75444 | GEO
Project description:The epithelial-mesenchymal transition (EMT), considered essential for metastatic cancer, has been a focus of much research, but important questions remain. Here, we show that silencing or removing H2A.X, a histone H2A variant involved in cellular DNA repair and robust growth, induced mesenchymal-like characteristics including activation of EMT transcription factors, Slug and ZEB1, in HCT116 human colon cancer cells. Ectopic H2A.X re-expression partially reversed these changes; as did silencing Slug and ZEB1. In an experimental metastasis model, the HCT116 parental and H2A.X-null cells exhibited similar metastases levels, but the cells with re-expressed H2A.X exhibited substantially elevated levels. We surmise that H2A.X re-expression led to partial EMT reversal and increased robustness in the HCT116 cells, permitting them to both form tumors and to metastasize. In a human adenocarcinoma panel, H2A.X levels correlated inversely with Slug and ZEB1 levels. Together, these results point to H2A.X as a novel regulator of EMT. 9 samples in total including 4 replicates of control shRNA and 5 replicates of shH2A.X.
2016-02-10 | E-GEOD-75444 | ArrayExpress
Project description:The epithelial-mesenchymal transition (EMT) is thought to be essential for cancer metastasis. While chromatin remodeling is involved in EMT, histone variants contribution in EMT remains poorly investigated. Recently, we showed that silencing or removal of the histone variant H2A.X induced mesenchymal-like characteristics, including activation of the EMT transcription factors, Slug and ZEB1, in human colon cancer cells. Here, we provide the evidence that H2A.X loss in human non-tumorigenic breast cell line MCF10A results in a robust EMT activation, as substantiated by a genome-wide expression analysis. Cells deficient for H2A.X exhibit enhanced migration and invasion, along with an activation of a set of mesenchymal genes and a concomitant repression of epithelial genes. In the breast model, the EMT-related transcription factor Twist1 cooperates with Slug to regulate EMT upon H2A.X loss. Of interest, H2A.X expression level tightly correlates with Twist1, and to a lesser extent with Slug in the panel of human breast cancer cell lines of the NCI-60 datasets. These new findings indicate that H2A.X is involved in the EMT processes in cells of different origins but pairing with transcription factors for EMT may be tissue specific. Overall design: 10 samples in total including 5 replicates of parental MCF10A cells and 5 replicates of H2A.X knockout cells.
2016-06-21 | GSE80180 | GEO
Project description:The epithelial-mesenchymal transition (EMT) is thought to be essential for cancer metastasis. While chromatin remodeling is involved in EMT, which processes contribute to this remodeling remain poorly investigated. Recently, we showed that silencing or removal of the histone variant H2A.X induced mesenchymal-like characteristics, including activation of the EMT transcription factors, Slug and Zeb1 in human colon cancer cells. Here, we provide the evidence that H2A.X loss in human non-tumorigenic breast cell line MCF10A results in a robust EMT activation, as substantiated by a genome-wide expression analysis. Cells deficient for H2A.X exhibit enhanced migration and invasion, along with an activation of a set of mesenchymal genes and a concomitant repression of epithelial genes. In the breast model, the EMT-related transcription factor Twist1 cooperates with Slug to regulate EMT upon H2A.X Loss. Of interest, H2A.X expression level tightly correlates with Twist1, and to a lesser extent with Slug in the panel of human breast cancer cell lines of the NCI-60 datasets. These new findings indicate that H2A.X is involved in the EMT processes in cells of different origins but pairing with transcription factors for EMT may be tissue specific.
| S-EPMC5026799 | BioStudies
Project description:The E-box-binding zinc finger transcription factors Slug and ZEB1 are important repressors of E-cadherin, contributing to epithelial-mesenchymal transition (EMT) in primary epithelial cancers. Activator or repressor status of EMT transcription factors defines consequences for tumorigenesis. We show that changes in expression levels of Slug in melanoma cell lines lead to concomitant alterations of ZEB1 expression. Electrophoretic mobility shift, luciferase reporter, and chromatin immunoprecipitation assays identified Slug as a direct transcriptional activator at E-boxes of the ZEB1 promoter. Transcriptional activation of ZEB1 was demonstrated to be specific for Slug, as EMT regulators Snail and Twist failed to influence ZEB1 expression. Slug and ZEB1 cooperatively repressed E-cadherin expression resulting in decreased adhesion to human keratinocytes, but promoted migration of melanoma cells. Our results show that the transcriptional activity of ZEB1 is increased by Slug, suggesting a hierarchical organized expression of EMT transcription factors through directed activation, triggering an EMT-like process in melanoma.
| S-EPMC3182526 | BioStudies
Project description:It has widely accepted that 5-methylcytosine is the only form of DNA methylation in mammalian genomes, whereas the other forms, such as N6-methyladenine, primarily exist in prokaryotes and only a few eukaryotes. Herein, we demonstrated the surprising presence of N6-methyladenine in mammalian genomes, especially, mouse embryonic stem cells. This modification is enriched at histone variant H2A.X-deposited genomic regions in wild type embryonic stem cells. Our work also showed that a previously unknown DNA demethylase, Alkbh1, is the major demethylase for N6-methyladenine in embryonic stem cells. Increase of N6-methyladenine levels in Alkbh1 deficient cells leads to silencing of genes that regulate embryonic development. Surprisingly, genes located on the X-chromosome, but not the Y-chromosome or autosomes are preferentially silenced by N6-methyladenine. Strikingly, N6-methyladenine in Alkbh1 deficient cells are specifically deposition at young, full-length subfamilies of LINE1 transposons that are strongly enriched on the X chromosome. Furthermore, N6-methyladenine deposition on LINE1s pattern is inversely correlated with their evolutionary age. The deposition of N6-methyladenine results in epigenetic silencing of such L1s, which are otherwise actively transcribed in wild type embryonic stem cells, and the neighboring enhancers and genes. Furthermore, N6-methyladenine induced-silencing resists gene activation signals during embryonic stem cell differentiation. Thus, N6-methyladenine adopts a new function in epigenetic silencing in evolution, distinct from its role in gene activation in other organisms. In summary, our results demonstrate that N6-methyladenine unexpectedly constitutes a crucial component of the epigenetic regulation repertoire in mammalian genomes. First, we used a native-ChIP approach to enrich for DNA molecules residing in H2A.X-deposition regions in mouse ESCs as previously described. Then, co-purified DNA molecules from WT or KO ESCs were subject to SMRT sequencing and data analysis for DNA modifications (Pacific Biosciences). H2A.X Native ChIP coupling with SMRT sequencing (separate the short "S" and long "L" part to sequencing)
| E-GEOD-71940 | BioStudies
Project description:Epithelial-mesenchymal transition (EMT) plays a fundamental role in cancer metastasis. The ubiquitin ligase FBXW7, a general tumor suppressor in human cancer, has been implicated in diverse cellular processes, however, its role in cholangiocarcinoma (CCA) metastasis has not been identified. Here, we report a crucial role of FBXW7 in CCA metastasis by regulating EMT. Loss of FBXW7 expression was detected in CCA cells and clinical specimens. Clinicopathological analysis revealed a close correlation between FBXW7 deficiency and metastasis, TNM stage and differentiation in intrahepatic CCA and perihilar CCA. Moreover, FBXW7 silencing in CCA cells dramatically promoted EMT, stem-like capacity and metastasis both in vitro and in vivo. Conversely, FBXW7 overexpression attenuated these processes. Mechanistically, treatment with rapamycin, a mTOR inhibitor, inhibited EMT, stem-like capacity and metastasis induced by FBXW7 silencing both in vitro and in vivo. Furthermore, the expression of EMT regulating transcription factors, snail, slug and ZEB1, were also decreased markedly with rapamycin treatment. In addition, silencing ZEB1 inhibited EMT and metastasis of both CCA cells and FBXW7 deficient CCA cells, which implicated the potential role of ZEB1 in FBXW7/mTOR signaling pathway related CCA metastasis. In conclusion, our findings defined a pivotal function of FBXW7 in CCA metastasis by regulating EMT.
| S-EPMC4467439 | BioStudies
Project description:microRNA-374a (miR-374a) exhibits oncogenic functions in various tumor types. Here we report that miR-374a suppresses proliferation, invasion, migration and intrahepatic metastasis in colon adenocarcinoma cell lines HCT116 and SW620. Notably, we detected that PI3K/AKT signaling and its downstream cell cycle factors including c-Myc, cyclin D1 (CCND1), CDK4 and epithelial-mesenchymal transition (EMT)-related genes including ZEB1, N-cadherin, Vimentin, Slug, and Snail were all significantly downregulated after miR-374a overexpression. Conversely, cell cycle inhibitors p21 and p27 were upregulated. Expression of E-cadherin was only decreased in HCT116, without any obvious differences observed in SW620 cells. Furthermore, luciferase reporter assays confirmed that miR-374a could directly reduce CCND1. Interestingly, when CCND1 was silenced or overexpressed, levels of pPI3K, pAkt as well as cell cycle and EMT genes were respectively downregulated or upregulated. We examined miR-374a levels by in situ hybridization and its correlation with CCND1 expression in CRC tumor tissues. High miR-374a expression with low level of CCND1 was protective factor in CRC. Together these findings indicate that miR-374a inactivates the PI3K/AKT axis by inhibiting CCND1, suppressing of colon cancer progression.
| S-EPMC5173061 | BioStudies
Project description:Background: Oxaliplatin (OXA) chemotherapy is widely used in the clinical treatment of colon cancer. However, chemo-resistance is still a barrier to effective chemotherapy in cases of colon cancer. Accumulated evidence suggests that the epithelial mesenchymal transition (EMT) may be a critical factor in chemo-sensitivity. The present study investigated the effects of Zinc finger E-box binding homeobox 1 (ZEB1) on OXA-sensitivity in colon cancer cells. Method: ZEB1expression and its correlation with clinicopathological characteristics were analyzed using tumor tissue from an independent cohort consisting of 118 colon cancer (CC) patients who receiving OXA-based chemotherapy. ZEB1 modulation of OXA-sensitivity in colon cancer cells was investigated in a OXA-resistant subline of HCT116/OXA cells and the parental colon cancer cell line: HCT116. A CCK8 assay was carried out to determine OXA-sensitivity. qRT-PCR, Western blot, Scratch wound healing and transwell assays were used to determine EMT phenotype of colon cells. ZEB1 knockdown using small interfering RNA (siRNA) was used to determine the ZEB1 contribution to OXA-sensitivity in vitro and in vivo (in a nude mice xenograft model). Result: ZEB1 expression was significantly increased in colon tumor tissue, and was correlated with lymph node metastasis and the depth of invasion. Compared with the parental colon cancer cells (HCT116), HCT116/OXA cells exhibited an EMT phenotype characterized by up-regulated expression of ZEB1, Vimentin, MMP2 and MMP9, but down-regulated expression of E-cadherin. Transfection of Si-ZEB1 into HCT116/OXA cells significantly reversed the EMT phenotype and enhanced OXA-sensitivity in vitro and in vivo. Conclusion: HCT116/OXA cells acquired an EMT phenotype. ZEB1 knockdown effectively restored OXA-sensitivity by reversing EMT. ZEB1 is a potential therapeutic target for the prevention of OXA-resistance in colon cancer.
| S-EPMC5687171 | BioStudies