Project description:RNA-seq was performed on parental HCT116 colon cancer cell line and on HCT116 DKO (double knock-out) cell line, which contains genetic knockouts of both DNA methyltransferases DNMT1 (-/-) and DNMT3b (-/-).
Project description:This study aimed to investigate the link between DNA methylation and protein expression on a genome wide level, using a combination of MBD-sequencing and shotgun and positional proteomics on two human colon cancer cell lines: a wild type HCT116 cell line and a double knock out HCT116 cell line (DNMT1 -/- and DNMT3b -/-). The protein content of the HCT116 WT and DKO cell lines was not only analyzed using a standard shotgun proteomics approach, but also with the N-terminal COFRADIC technique (Staes et al., 2011), in order to determine the (alternative) translation start site of the expressed proteins.
Project description:Recent studies have shown that circular RNAs (circRNAs) are abundant, widely expressed in mammals, and can display cell-type specific expression. However, how production of circRNAs is regulated and their precise biological function remains largely unknown. To study how circRNAs might be regulated during colorectal cancer progression, we used three isogenic colon cancer cell lines that differ only in KRAS mutation status. Cellular RNAs from the parental DLD-1 cells that contain both wild-type and G13D mutant KRAS alleles and isogenically-matched derivative cell lines, DKO-1 (mutant KRAS allele only) and DKs-8 (wild-type KRAS allele only) were analyzed using RNA-Seq. We developed a bioinformatics pipeline to identify and evaluate circRNA candidates from RNA-Seq data. Hundreds of high-quality circRNA candidates were identified in each cell line. Remarkably, circRNAs were significantly down-regulated at a global level in DLD-1 and DKO-1 cells compared to DKs-8 cells, indicating a widespread effect of mutant KRAS on circRNA abundance. This finding was confirmed in two independent colon cancer cell lines HCT116 (KRAS mutant) and HKe3 (KRAS WT). In all three cell lines, circRNAs were also found in secreted extracellular-vesicles, and circRNAs were more abundant in exosomes than cells. Our results suggest that circRNAs may serve as promising cancer biomarkers.
Project description:Chromatogram library generated of pooled sample. Coculture spheroids formed from fibroblast and colon cancer cell lines, and monoculture spheroids formed from the colon cancer cell line HCT116.
Project description:Genome-wide view of the interplay between methylation and RNA expression in this colorectal cancer model was obtained. RNA-sequencing of HCT116 cell line, the DNMT1 and DNMT3B double knock-out HCT116 cell line (DKO), and 7 additional colorectal cell lines.
Project description:In our study we applied a genome-wide DNA methylation analysis approach, MethylCap-seq, to map the differentially methylated regions in 24 tumor and matched normal colon samples. In total, 2687 frequently hypermethylated and 468 frequently hypomethylated regions were identified, which include potential biomarkers for CRC diagnosis. Hypermethylation in the tumor samples was enriched at CpG islands and gene promoters, while hypomethylation was distributed throughout the genome. Using epigenetic data from human embryonic stem cells, we show that frequent differentially methylated regions (DMRs) coincide with bivalent loci in human embryonic stem cells. DNA methylation is commonly thought to lead to cancer gene related silencing, however integration of publically available expression analysis shows that 75% of the frequently hypermethylation genes were most likely already lowly or not expressed in normal tissue. Collectively, our study provides genome-wide DNA methylation maps of colon cancer, comprehensive lists of DMRs, and gives further clues on the role of aberrant DNA methylation in CRC formation. To investigate DNA methylation in CRC in a genome-wide unbiased fashion, we applied MethylCap-seq. This method involves capture of methylated DNA using the MBD domain of MeCP2, and subsequent next-generation Illumina sequencing of eluted DNA. In addition, we compared MethylCap with RNA-seq and ChIP-seq profiles of H3K4me3 and H3K27me3 for the colon cancer tumor cell line HCT116 (HCT116 WT) and the cell line of HCT116 with DNMT1 and DNMT3b knockout (HCT116 DKO).
