Project description:Instructive mechanisms are present for induction of DNA methylation, as shown by methylation of specific CpG islands (CGIs) by specific inducers and in specific cancers. However, instructive factors involved are poorly understood, except for involvement of low transcription and trimethylation of histone H3 lysine 27 (H3K27me3). Here, we used methylated DNA immunoprecipitation (MeDIP) combined with a CGI oligonucleotide microarray analysis, and identified 5510 and 521 genes with promoter CGIs resistant and susceptible, respectively, to DNA methylation in prostate cancer cell lines. Expression analysis revealed that the susceptible genes had low transcription in a normal prostatic epithelial cell line. Chromatin immunoprecipitation with microarray hybridization (CHiP-chip) analysis of RNA polymerase II (Pol II) and histone modifications showed that, even among the genes with low transcription, the presence of Pol II was associated with marked resistance to DNA methylation (OR = 0.22; 95% CI = 0.12-0.38), and H3K27me3 was associated with increased susceptibility (OR = 11.20; 95% CI = 7.14-17.55). The same was true in normal human mammary epithelial cells for 5430 and 733 genes resistant and susceptible, respectively, to DNA methylation in breast cancer cell lines. These results showed that the presence of Pol II, active or stalled, and H3K27me3 can predict the epigenetic fate of promoter CGIs independently of transcription levels. To analyze DNA methylation status in normal and cancer cells, MeDIP-CGI oligonucleotide microarray analysis was performed. To analyze expression and histone modification status in normal cells, GeneChip analysis and ChIP-oligonucleotide microarray analysis were performed.
Project description:Genome wide DNA methylation profiling of ovarian cancer cell lines and normal cells. The Illumina Infinium 27k Human DNA methylation Beadchip was used to obtain DNA methylation profiles for approximately 27,000 CpGs. Samples included 46 ovarian cancer cell lines, 4 normal counterparts and 8 controls.
Project description:Genome wide DNA methylation profiling of normal gastric epuithelial cells and gastric cancer cell lines. The Illumina Infinium 450k Human DNA methylation Beadchip v1.2 was used to obtain DNA methylation profiles across approximately 450,000 CpGs. Samples included 2 normal gastric epithelial cells and 14 gastric cancer cells.
Project description:Genome-wide DNA-methylation profiles of human lung cancer cell lines and normal lung cells were generated by Infinium bead chip technology DNA methylation patterns of over 480,000 CpG sites were analyzed in normal human bronchial epithelial cells (NHBEC) and three non small cell lung cancer cell lines (NSCLC: A427, A549 and H322) using bisulfite-based Illumina 450K BeadChip arrays
Project description:Instructive mechanisms are present for induction of DNA methylation, as shown by methylation of specific CpG islands (CGIs) by specific inducers and in specific cancers. However, instructive factors involved are poorly understood, except for involvement of low transcription and trimethylation of histone H3 lysine 27 (H3K27me3). Here, we used methylated DNA immunoprecipitation (MeDIP) combined with a CGI oligonucleotide microarray analysis, and identified 5510 and 521 genes with promoter CGIs resistant and susceptible, respectively, to DNA methylation in prostate cancer cell lines. Expression analysis revealed that the susceptible genes had low transcription in a normal prostatic epithelial cell line. Chromatin immunoprecipitation with microarray hybridization (CHiP-chip) analysis of RNA polymerase II (Pol II) and histone modifications showed that, even among the genes with low transcription, the presence of Pol II was associated with marked resistance to DNA methylation (OR = 0.22; 95% CI = 0.12-0.38), and H3K27me3 was associated with increased susceptibility (OR = 11.20; 95% CI = 7.14-17.55). The same was true in normal human mammary epithelial cells for 5430 and 733 genes resistant and susceptible, respectively, to DNA methylation in breast cancer cell lines. These results showed that the presence of Pol II, active or stalled, and H3K27me3 can predict the epigenetic fate of promoter CGIs independently of transcription levels.
Project description:H3K27me3 statuses were analyzed in normal mouse colonic epithelial cells and in those exposed to DSS-induced colitis, and aberrant changes of H3K27me3 by DSS-induced colitis were identified.