Project description:Genome-wide methylation analysis was performed by methylated DNA immunoprecipitation (MeDIP)-CpG island (CGI) microarray analysis to identify candidate CGIs specifically methylated in mouse colon tumors associated with colitis. We sucessfully identified 23 candidate CGIs methylated in tumors.
Project description:Promoter hypermethylation divides colon cancers into subtypes with and without a CpG island methylator phenotype (CIMP). Here, we performed genome-wide DNA methylation profiling of colonic normal and tumor tissues to dissect development of CpG hypermethylation in colon carcinogenesis. This identified age-environment related versus genetically driven CpG hypermethylation, the latter being associated with CIMP cancers. We found a strong association between BRAFV600E mutation and downregulation of the DNA demethylases TET1 and TET2. Expression of BRAFV600E in CIMP cancer cells suppressed TET1 transcription, which was sufficient to establish hypermethylation at CIMP genes promoters, including that of TET2. This phenotype was reverted by the BRAFV600E inhibitor vemurafenib. Thus, BRAFV600E, via impairment of cytosine de-methylation, is a genetic driver of CIMP in colon tumorigenesis.
Project description:Promoter hypermethylation divides colon cancers into subtypes with and without a CpG island methylator phenotype (CIMP). Here, we performed genome-wide DNA methylation profiling of colonic normal and tumor tissues to dissect development of CpG hypermethylation in colon carcinogenesis. This identified age-environment related versus genetically driven CpG hypermethylation, the latter being associated with CIMP cancers. We found a strong association between BRAFV600E mutation and downregulation of the DNA demethylases TET1 and TET2. Expression of BRAFV600E in CIMP cancer cells suppressed TET1 transcription, which was sufficient to establish hypermethylation at CIMP genes promoters, including that of TET2. This phenotype was reverted by the BRAFV600E inhibitor vemurafenib. Thus, BRAFV600E, via impairment of cytosine de-methylation, is a genetic driver of CIMP in colon tumorigenesis.
Project description:Promoter hypermethylation divides colon cancers into subtypes with and without a CpG island methylator phenotype (CIMP). Here, we performed genome-wide DNA methylation profiling of colonic normal and tumor tissues to dissect development of CpG hypermethylation in colon carcinogenesis. This identified age-environment related versus genetically driven CpG hypermethylation, the latter being associated with CIMP cancers. We found a strong association between BRAFV600E mutation and downregulation of the DNA demethylases TET1 and TET2. Expression of BRAFV600E in CIMP cancer cells suppressed TET1 transcription, which was sufficient to establish hypermethylation at CIMP genes promoters, including that of TET2. This phenotype was reverted by the BRAFV600E inhibitor vemurafenib. Thus, BRAFV600E, via impairment of cytosine de-methylation, is a genetic driver of CIMP in colon tumorigenesis.
Project description:Promoter hypermethylation divides colon cancers into subtypes with and without a CpG island methylator phenotype (CIMP). Here, we performed genome-wide DNA methylation profiling of colonic normal and tumor tissues to dissect development of CpG hypermethylation in colon carcinogenesis. This identified age-environment related versus genetically driven CpG hypermethylation, the latter being associated with CIMP cancers. We found a strong association between BRAFV600E mutation and downregulation of the DNA demethylases TET1 and TET2. Expression of BRAFV600E in CIMP cancer cells suppressed TET1 transcription, which was sufficient to establish hypermethylation at CIMP genes promoters, including that of TET2. This phenotype was reverted by the BRAFV600E inhibitor vemurafenib. Thus, BRAFV600E, via impairment of cytosine de-methylation, is a genetic driver of CIMP in colon tumorigenesis.
Project description:Promoter hypermethylation divides colon cancers into subtypes with and without a CpG island methylator phenotype (CIMP). Here, we performed genome-wide DNA methylation profiling of colonic normal and tumor tissues to dissect development of CpG hypermethylation in colon carcinogenesis. This identified age-environment related versus genetically driven CpG hypermethylation, the latter being associated with CIMP cancers. We found a strong association between BRAFV600E mutation and downregulation of the DNA demethylases TET1 and TET2. Expression of BRAFV600E in CIMP cancer cells suppressed TET1 transcription, which was sufficient to establish hypermethylation at CIMP genes promoters, including that of TET2. This phenotype was reverted by the BRAFV600E inhibitor vemurafenib. Thus, BRAFV600E, via impairment of cytosine de-methylation, is a genetic driver of CIMP in colon tumorigenesis. Genome-wide DNA methylation profiling of adjacent non-tumor colon tissue and colon adenocarcinoma samples. The Illumina Infinium 27k Human DNA methylation Beadchip v1.2 was used to obtain DNA methylation profiles across approximately 27,000 CpGs. Samples included 8 colon cancer tissues and their associated healthy mucosa (CAM).
Project description:We compare the methylation status of CpG island clones by MeDIP in SW48 colon cancer cells relative to normal colon mucosa and WI38 primary fibroblasts. Keywords: ordered
Project description:The methylation status of colon epithelial cells was profiled in wild type mice and mice expressing a Dnmt3b transgene. Genome-scale methylation profiles were generated using reduced representation bisulfite sequencing (RRBS), with CpG methylation scored by promoter and also summarized by gene. Dnmt3b expression is associated with a strong increase in de novo methylation of a discrete subset of "methylation sensitive" genes which show a strong concordance with genes methylated in human colon cancer. These results, together with further analysis, indicate that colon epithelial cell methylation in the Dnmt3b mouse model predicts DNA methylation of human colon cancer with high confidence.
Project description:Integration of synthetic CpG Free DNA induces de novo DNAme in the flanking CpG island. Cellular differentiation requires global changes to DNA methylation (DNAme), where it functions to regulate transcription factor and chromatin remodeling activity, and genome interpretation. Here, we describe a simple DNAme engineering approach in pluripotent stem cells (PSCs), extending across large stretches of CpG dense “islands (CGIs).” Integration of synthetic CpG free single-stranded DNA (ssDNA) induces a target CpG Island Methylation Response (CIMR) in multiple PSC lines, Nt2d1 embryonal carcinoma cells, and mouse PSCs, but not in highly methylated CpG Island Methylator Phenotype (CIMP) positive cancer lines. CIMR DNAme at MLH1 spans the CGI, is robustly maintained throughout cellular differentiation, suppresses target gene activity, and sensitizes derived cardiomyocytes and thymic epithelial cells to the chemotherapy cisplatin. Additional CIMR DNAme is reported on at TP53 and ONECUT1 CGIs. Collectively, this new resource enables total CpG Island DNAme engineering in pluripotency and the genesis of novel epigenetic models of development and disease