Homo sapiens
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PROVIDER: PRJNA301997 | ENA |
REPOSITORIES: ENA
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Project description:Long noncoding RNAs (lncRNAs) have emerged as key components in multiple cellular processes, although their physiological and pathological functions are not fully understood. To identify cancer-related lncRNAs, we screened for those that are epigenetically silenced in colorectal cancer (CRC). Through a genome-wide analysis of histone modifications in CRC cells, we found that the transcription start sites (TSSs) of 1,027 lncRNA genes acquired trimethylation of histone H3 lysine 4 (H3K4me3) after DNA demethylation. Integrative analysis of chromatin signatures and the DNA methylome revealed that the promoter CpG islands (CGIs) of 66 lncRNA genes contained cancer-specific methylation. By validating the expression and methylation of lncRNA genes in CRC cells, we ultimately identified 20 lncRNAs, including ZNF582-AS1, as targets of epigenetic silencing in CRC. ZNF582-AS1 is frequently methylated in CRC cell lines (87.5%), primary CRCs (77.2%), colorectal adenomas (44.7%) and advanced adenomas (87.8%), suggesting that this methylation is an early event during colorectal tumorigenesis. Methylation of ZNF582-AS1 is associated with poor survival of CRC patients, and ectopic expression of ZNF582-AS1 suppressed colony formation by CRC cells. Our findings offer insight into the association between epigenetic alterations and lncRNA dysregulation in cancer and suggest that ZNF582-AS1 may be a novel tumor-suppressive lncRNA.
2015-11-13 | GSE74945 | GEO
Project description:Methylation-silenced genes in colorectal cancer cell lines
| PRJNA99441 | ENA
Project description:Using an oligonucleotide array, we undertook a genome-wide search for genes upregulated following treatment with a demethylating agent in two CRC cell lines. Promoter methylation status was determined in 12 CRC cell lines and 11 CRC tissues. After the treatment, 350 genes were upregulated 1.5 fold or more. Six genes (PAGE-5, VCX, MAEL, GAGED2, UCHL1, and GAGE7), which contained putative 5'CpG islands in their promoter regions, were confirmed to be silenced in CRC cell lines. The median level of UCHL1 gene expression in cell lines with methylation was significantly lower than that in cell lines without methylation (P = 0.032). The level of methylation of UCHL1 was significantly higher in tumors than in corresponding normal mucosae (P = 0.005). Chemical genomic screening led to the identification of a specific promoter subject to hypermethylation in CRC. These results suggest that aberrant promoter methylation is the primary mechanism of transcriptional silencing of the UCHL1 gene and that methylation of the UCHL1 gene promoter increases during the development and progression of CRC Keywords: Methylation Analysis This study explored methylation-silenced genes in colorectal cancer (CRC) cell lines. Using an oligonucleotide array, a genome-wide search for genes upregulated following treatment with a demethylating agent, 5-aza-2â??-deoxycitidine, in two CRC cell lines, DLD-1 and HT-29, was performed. Promoter methylation status of candidate genes silenced and upregulated following the treatment was determined in 12 CRC cell linesby methylation-specific PCR.
2010-06-11 | E-GEOD-7687 | biostudies-arrayexpress
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:UHRF1 is a major regulator of epigenetic mechanism and is overexpressed in various human malignancies. In this study, we examined the involvement of UHRF1 in aberrant DNA methylation in colorectal cancer (CRC). In CRC cells, transient UHRF1 knockdown rapidly induced DNA demethylation across entire genomic regions, including CpG islands, gene bodies and repetitive elements. Nonetheless, UHRF1 depletion only minimally reversed CpG island hypermethylation-associated gene silencing. However, the combination of UHRF1 depletion and histone deacetylase (HDAC) inhibition synergistically reactivated the silenced genes and strongly suppressed CRC cell proliferation. Our results suggest that (i) maintenance of DNA methylation in CRC cells is highly dependent on UHRF1; (ii) UHRF1 depletion rapidly induces DNA demethylation, though it is insufficient to fully reactivate the silenced genes; and (iii) dual targeting of UHRF1 and HDAC may be an effective new therapeutic strategy.
2019-05-21 | GSE106438 | GEO
Project description:UHRF1 is a major regulator of epigenetic mechanism and is overexpressed in various human malignancies. In this study, we examined the involvement of UHRF1 in aberrant DNA methylation in colorectal cancer (CRC). In CRC cells, transient UHRF1 knockdown rapidly induced DNA demethylation across entire genomic regions, including CpG islands, gene bodies and repetitive elements. Nonetheless, UHRF1 depletion only minimally reversed CpG island hypermethylation-associated gene silencing. However, the combination of UHRF1 depletion and histone deacetylase (HDAC) inhibition synergistically reactivated the silenced genes and strongly suppressed CRC cell proliferation. Our results suggest that (i) maintenance of DNA methylation in CRC cells is highly dependent on UHRF1; (ii) UHRF1 depletion rapidly induces DNA demethylation, though it is insufficient to fully reactivate the silenced genes; and (iii) dual targeting of UHRF1 and HDAC may be an effective new therapeutic strategy.
2019-05-21 | GSE106437 | GEO
Project description:UHRF1 is a major regulator of epigenetic mechanism and is overexpressed in various human malignancies. In this study, we examined the involvement of UHRF1 in aberrant DNA methylation in colorectal cancer (CRC). In CRC cells, transient UHRF1 knockdown rapidly induced DNA demethylation across entire genomic regions, including CpG islands, gene bodies and repetitive elements. Nonetheless, UHRF1 depletion only minimally reversed CpG island hypermethylation-associated gene silencing. However, the combination of UHRF1 depletion and histone deacetylase (HDAC) inhibition synergistically reactivated the silenced genes and strongly suppressed CRC cell proliferation. Our results suggest that (i) maintenance of DNA methylation in CRC cells is highly dependent on UHRF1; (ii) UHRF1 depletion rapidly induces DNA demethylation, though it is insufficient to fully reactivate the silenced genes; and (iii) dual targeting of UHRF1 and HDAC may be an effective new therapeutic strategy.
2019-05-21 | GSE106402 | GEO
Project description:UHRF1 is a major regulator of epigenetic mechanism and is overexpressed in various human malignancies. In this study, we examined the involvement of UHRF1 in aberrant DNA methylation in colorectal cancer (CRC). In CRC cells, transient UHRF1 knockdown rapidly induced DNA demethylation across entire genomic regions, including CpG islands, gene bodies and repetitive elements. Nonetheless, UHRF1 depletion only minimally reversed CpG island hypermethylation-associated gene silencing. However, the combination of UHRF1 depletion and histone deacetylase (HDAC) inhibition synergistically reactivated the silenced genes and strongly suppressed CRC cell proliferation. Our results suggest that (i) maintenance of DNA methylation in CRC cells is highly dependent on UHRF1; (ii) UHRF1 depletion rapidly induces DNA demethylation, though it is insufficient to fully reactivate the silenced genes; and (iii) dual targeting of UHRF1 and HDAC may be an effective new therapeutic strategy.
2019-05-21 | GSE113664 | GEO
Project description:In mammals, many germline genes are repressed by epigenetic mechanisms to prevent their illegitimate expression in embryonic and somatic cells. To advance our understanding of the complete mechanisms restricting the expression of germline genes in mammals, we analyzed the chromatin signature of germline genes and performed a genome-wide CRISPR-Cas9 knock-out screen for genes involved in germline gene repression using a reporter system in which GFP is under the control of the epigenetically repressed Dazl germline promoter in mouse embryonic stem cells (ESCs). We showed that the repression of germline genes mainly depends on the polycomb complex PRC1.6 and DNA methylation, which function additively in mouse ESCs. Furthermore, we identified and validated several novel genes involved in the repression of germline genes, and characterized three of them: Usp7, Shfm1 (also known as Sem1) and Erh. Inactivation of Usp7, Shfm1 or Erh led to the upregulation of germline genes, as well as retrotransposons for Shfm1, in mouse ESCs. Functionally, Usp7 acts at two levels: firstly it associates with PRC1.6 components and represses germline genes independently of DNA methylation, and secondly it facilitates DNA methylation deposition at germline genes for long term repression. In summary, our study provides a global view of the epigenetic mechanisms and novel factors required for silencing germline genes in embryonic cells.
2023-02-03 | PXD030666 | Pride
Project description:1. Evaluate the diagnostic value of long noncoding RNA (CCAT1) expression by RT-PCR in peripheral blood in colorectal cancer patients versus normal healthy control personal.
2. Evaluate the clinical utility of detecting long noncoding RNA (CCAT1) expression in diagnosis of colorectal cancer patients & its relation to tumor staging.
3. Evaluate the clinical utility of detecting long noncoding RNA (CCAT1) expression in precancerous colorectal diseases.
4. Compare long noncoding RNA (CCAT1) expression with traditional marker; carcinoembryonic antigen (CEA) and Carbohydrate antigen 19-9 (CA19-9) in diagnosis of colorectal cancer.
| 2330122 | ecrin-mdr-crc