Characterization of epigenetically silenced microRNAs in liver cancer cells
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA508302 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Numerous studies have described the critical role played by microRNAs (miRNAs) in cancer progression and the potential of these small non-coding RNAs for diagnostic or therapeutic applications. However, the mechanisms responsible for the altered expression of miRNAs in malignant cells remain poorly understood. Herein, via epigenetic unmasking, we identified a group of miRNAs located in the imprinted delta like non-canonical Notch ligand 1 (DLK1)-maternally expressed 3 (MEG3) locus that were repressed in hepatic tumor cells. Notably, miR-493-5p epigenetic silencing was correlated with hypermethylation of the MEG3-differentially regulated region (DMR) in liver cancer cell lines and tumor tissues from patients. Experimental rescue of miR-493-5p promoted an anti-cancer response by hindering hepatocellular carcinoma (HCC) cell growth in vitro and tumor progression in vivo. We found that miR-493-5p mediated part of its tumor-suppressor activity by abrogating overexpression of insulin-like growth factor 2 (IGF2) and the IGF2-derived intronic oncomir miR-483-3p in HCC cells characterized by IGF2 loss of imprinting (LOI). In summary, this study describes an unknown miRNA-dependent regulatory mechanism between two distinct imprinted loci and a possible therapeutic window for liver cancer patients exhibiting IGF2-miR-483 LOI and amplification.
2018-12-05 | GSE123314 | GEO
Project description:Cyclin-Dependent Kinase 9 (CDK9) as part of the PTEFb complex promotes transcriptional elongation by promoting RNAPII pause release. We now report that, paradoxically, CDK9 is also essential for maintaining gene silencing at heterochromatic loci. Through a live cell screen, we discovered that CDK9 inhibition reactivates epigenetically silenced genes in cancer, leading to restored tumor suppressor gene expression and cell differentiation, along with activation of endogenous retrovirus (ERV) genes. CDK9 inhibition dephosphorylates the SWI/SNF protein SMARCA4 and represses HP1α expression, both of which contribute to gene reactivation. Based on gene activation, we developed the highly selective and potent CDK9 inhibitor MC180295 (IC50 =5.1nM) that has broad anti-cancer activity in-vitro and is effective in in-vivo cancer models. Additionally, CDK9 inhibition sensitizes with the immune checkpoint inhibitor α-PD-1 in vivo, making it an excellent target for epigenetic therapy of cancer.
2020-05-26 | PXD007925 | Pride
Project description:Of the seven in absentia homologue (SIAH) family, three members have been identified in the human genome. In contrast to the E3 ubiquitin ligase encoding SIAH1 and SIAH2, little is known on the regulation and function of SIAH3 in tumorigenesis. In this study, we reveal that SIAH3 is frequently epigenetically silenced in different cancer entities, including cutaneous melanoma, lung adenocarcinoma and head and neck cancer. Low SIAH3 levels correlate with an impaired survival of cancer patients. Additionally, induced expression of SIAH3 reduces cell proliferation. Functionally, SIAH3 negatively affects cellular metabolism by shifting cells form aerobic oxidative phosphorylation to glycolysis. SIAH3 is localized in the mitochondrion and interacts with proteins involved in mitochondrial ribosome biogenesis and translation. We also report that SIAH3 interacts with ubiquitin ligases, including SIAH1 or SIAH2, and is degraded by them. These results suggest that SIAH3 acts as an epigenetically controlled tumor suppressor by regulating cellular metabolism through the inhibition of oxidative phosphorylation.
2024-01-12 | MSV000093850 | MassIVE
Project description:Abnormal miRNA expression has been linked to the development and progression of human cancers, and such dysregulation can result from aberrant DNA methylation. We combined the analysis of miRNA expression data deposited with empirical DNA methylation data in HCT116 and DKO colon cancer cells (SRA accession# SRP001414) to identify novel DNA methylation regulated miRNAs. ABSTRACT: Abnormal microRNA (miRNA) expression has been linked to the development and progression of several human cancers, and such dysregulation can result from aberrant DNA methylation. While a small number of miRNAs is known to be regulated by DNA methylation, we postulated that such epigenetic regulation is more prevalent. By combining MBD-isolated Genome Sequencing (MiGS) to evaluate genome-wide DNA methylation patterns and microarray analysis to determine miRNA expression levels, we systematically searched for candidate miRNAs regulated by DNA methylation in colorectal cancer cell lines. We found 64 miRNAs to be robustly methylated in HCT116 cells and/or DNMT-1 and 3B doubleknock cells (DKO); eighteen of them were located in imprinting regions or already reported to be regulated by DNA methylation. In the remaining 46 miRNAs, expression levels of 18 were consistent with their DNA methylation status. Finally, 10 miRNAs were up-regulated by 5-aza-2'-deoxycytidine treatment and identified to be novel miRNAs regulated by DNA methylation. Moreover, we demonstrated the functional relevance of these epigenetically silenced miRNAs by ectopically expressing select candidates, which resulted in inhibition of growth and migration of cancer cells. Our study also provides a reliable strategy to identify DNA methylation-regulated miRNAs by combining DNA methylation profiles and expression data. [miRNA expression]: Total RNA was extracted from 3 biological replicate sets of HCT116 and DMNT-1 and 3B double knock out HCT116 (DKO) colorectal cancer cells.
2011-05-20 | E-GEOD-26819 | biostudies-arrayexpress
Project description:Of the seven in absentia homologue (SIAH) family, three members have been identified in the human genome. In contrast to the E3 ubiquitin ligase encoding SIAH1 and SIAH2, little is known on the regulation and function of SIAH3 in tumorigenesis. In this study, we reveal that SIAH3 is frequently epigenetically silenced in different cancer entities, including cutaneous melanoma, lung adenocarcinoma and head and neck cancer. Low SIAH3 levels correlate with an impaired survival of cancer patients. Additionally, induced expression of SIAH3 reduces cell proliferation. Functionally, SIAH3 negatively affects cellular metabolism by shifting cells form aerobic oxidative phosphorylation to glycolysis. SIAH3 is localized in the mitochondrion and interacts with proteins involved in mitochondrial ribosome biogenesis and translation. We also report that SIAH3 interacts with ubiquitin ligases, including SIAH1 or SIAH2, and is degraded by them. These results suggest that SIAH3 acts as an epigenetically controlled tumor suppressor by regulating cellular metabolism through the inhibition of oxidative phosphorylation.
2024-01-12 | MSV000093851 | MassIVE
Project description:Abnormal miRNA expression has been linked to the development and progression of human cancers, and such dysregulation can result from aberrant DNA methylation. We combined the analysis of miRNA expression data deposited with empirical DNA methylation data in HCT116 and DKO colon cancer cells (SRA accession# SRP001414) to identify novel DNA methylation regulated miRNAs. ABSTRACT: Abnormal microRNA (miRNA) expression has been linked to the development and progression of several human cancers, and such dysregulation can result from aberrant DNA methylation. While a small number of miRNAs is known to be regulated by DNA methylation, we postulated that such epigenetic regulation is more prevalent. By combining MBD-isolated Genome Sequencing (MiGS) to evaluate genome-wide DNA methylation patterns and microarray analysis to determine miRNA expression levels, we systematically searched for candidate miRNAs regulated by DNA methylation in colorectal cancer cell lines. We found 64 miRNAs to be robustly methylated in HCT116 cells and/or DNMT-1 and 3B doubleknock cells (DKO); eighteen of them were located in imprinting regions or already reported to be regulated by DNA methylation. In the remaining 46 miRNAs, expression levels of 18 were consistent with their DNA methylation status. Finally, 10 miRNAs were up-regulated by 5-aza-2'-deoxycytidine treatment and identified to be novel miRNAs regulated by DNA methylation. Moreover, we demonstrated the functional relevance of these epigenetically silenced miRNAs by ectopically expressing select candidates, which resulted in inhibition of growth and migration of cancer cells. Our study also provides a reliable strategy to identify DNA methylation-regulated miRNAs by combining DNA methylation profiles and expression data.
2011-05-20 | GSE26819 | GEO
Project description:Abnormal microRNA (miRNA) expression has been linked to the development and progression of several human cancers, and such dysregulation can result from aberrant DNA methylation. While a small number of miRNAs is known to be regulated by DNA methylation, we postulated that such epigenetic regulation is more prevalent. By combining MBD-isolated Genome Sequencing (MiGS) to evaluate genome-wide DNA methylation patterns and microarray analysis to determine miRNA expression levels, we systematically searched for candidate miRNAs regulated by DNA methylation in colorectal cancer cell lines. We found 64 miRNAs to be robustly methylated in HCT116 cells; eighteen of them were located in imprinting regions or already reported to be regulated by DNA methylation. For the remaining 46 miRNAs, expression levels of 18 were consistent with their DNA methylation status. Finally, 8 miRNAs were up-regulated by 5-aza-2'-deoxycytidine treatment and identified to be novel miRNAs regulated by DNA methylation. Moreover, we demonstrated the functional relevance of these epigenetically silenced miRNAs by ectopically expressing select candidates, which resulted in inhibition of growth and migration of cancer cells. In addition to reporting these findings, our study also provides a reliable, systematic strategy to identify DNA methylation-regulated miRNAs by combining DNA methylation profiles and expression data.
| S-EPMC3116843 | biostudies-literature
Project description:Epigenetic deregulation plays a critical role in the pathogenesis of Acute Myeloid Leukemia. But changes in histone modification patterns at the epigenome level still remain largely unknown. Here, we analyzed alterations of histone H3 acetylation patterns in a large number of patients with AML compared to CD34+ progenitor cells. Using ChIP-Chip assays, we demonstrate that AML blasts exhibit significant changes in Histone H3 acetylation levels at more than 1000 genomic loci. Importantly, at core promoter regions losses of H3 acetlyation levels prevailed which suggested that a large number of genes is epigenetically silenced in AML. The validation of identified genes led to the discovery of Peroxiredoxin 2 (PRDX2) as a potential tumor suppressor gene in AML. Peroxiredoxin-2 (PRDX2) was silenced in most AML patients by decreased Histone H3 acetylation and in almost 20% by promoter DNA hypermethylation. Low protein expression of the antioxidant PRDX2 gene was clinically associated with a poor prognosis in AML patients. Functionally, PRDX2 acted as an inhibitor of myeloid cell growth by reducing levels of reactive oxygen species generated in response to cytokines. A high level of PRDX2 expression inhibited myc-induced murine leukemogenesis whereas loss of PRDX2 increased myeloid cell proliferation and accelerated myc-induced leukemogenesis. Taken together, we identify widespread loss of Histone H3 acetylation at core promoter regions as a signature of AML blasts. Epigenome wide analyses of histone H3 acetylation led to the identification of PRDX2 as an epigenetically silenced growth suppressor that contributed to the malignant phenotype in AML. Blasts from patients with AML (n=72) were obtained at the time of diagnosis (in a few cases at first relapse). CD34+ progenitor cells (n=17) and white blood cells (n=16) were used as control samples. Immunoprecipitations were performed for anti-acetylated Histone H3. Chromatin-IPs were amplified using ligation mediated PCR and labeled using Cy3 coupled to incorporated amino-allyl-UTP. Common reference DNA consisting of a mixture of genomic DNA from AML patients was prepared, amplified and labeled in a similar way with Cy5.
2011-12-16 | E-GEOD-27863 | biostudies-arrayexpress
Project description:UHRF1 depletion and HDAC inhibition synergistically reactivate epigenetically silenced genes in colorectal cancer cells
| PRJNA416872 | ENA
Project description:Epigenetic deregulation plays a critical role in the pathogenesis of Acute Myeloid Leukemia. But changes in histone modification patterns at the epigenome level still remain largely unknown. Here, we analyzed alterations of histone H3 acetylation patterns in a large number of patients with AML compared to CD34+ progenitor cells. Using ChIP-Chip assays, we demonstrate that AML blasts exhibit significant changes in Histone H3 acetylation levels at more than 1000 genomic loci. Importantly, at core promoter regions losses of H3 acetlyation levels prevailed which suggested that a large number of genes is epigenetically silenced in AML. The validation of identified genes led to the discovery of Peroxiredoxin 2 (PRDX2) as a potential tumor suppressor gene in AML. Peroxiredoxin-2 (PRDX2) was silenced in most AML patients by decreased Histone H3 acetylation and in almost 20% by promoter DNA hypermethylation. Low protein expression of the antioxidant PRDX2 gene was clinically associated with a poor prognosis in AML patients. Functionally, PRDX2 acted as an inhibitor of myeloid cell growth by reducing levels of reactive oxygen species generated in response to cytokines. A high level of PRDX2 expression inhibited myc-induced murine leukemogenesis whereas loss of PRDX2 increased myeloid cell proliferation and accelerated myc-induced leukemogenesis. Taken together, we identify widespread loss of Histone H3 acetylation at core promoter regions as a signature of AML blasts. Epigenome wide analyses of histone H3 acetylation led to the identification of PRDX2 as an epigenetically silenced growth suppressor that contributed to the malignant phenotype in AML.
2011-12-16 | GSE27863 | GEO