BioProject

Alternative cleavage and polyadenylation (APA) is a form of transcriptional regulation via shifts in how frequently multiple polyadenylation (polyA) sites within genes are used across biological conditions. More...

Alternative cleavage and polyadenylation (APA) is a form of transcriptional regulation via shifts in how frequently multiple polyadenylation (polyA) sites within genes are used across biological conditions. APA can result in transcripts with varying length and information content, and has been linked to gene regulation in both cancer and development. While trans-acting regulatory factors can cause changes in APA, the process of cleavage and polyadenylation is often co-transcriptional. We hypothesized that epigenetic changes, such as DNA methylation, may regulate APA co-transcriptionally. To identify genes where DNA methylation may regulate APA, we performed a genome-wide quantification of polyA site usage using a next generation sequencing technique. By priming the polyA-tails of an RNA library, we mapped cleavage sites and abundances with base-pair resolution across the genomes of two cell lines. The HCT116 cell line is derived from colon cancer, and contains cancer-associated DNA hypermethylation. The DKO cell line is derived from the parental HCT116 line, but has a near-complete depletion of DNA methylation due to mutations in DNA methyltransferase enzymes. Previous studies have used this sytem to detect genes where promoter DNA methylation regulates the gene expression of tumor suppressors. Analogously, detecting APA between HCT116 and DKO reveals candidate genes where DNA methylation may regulate the process of APA. Mechanistic experiments can further interrogate cross-talk between DNA methylation and APA at these loci, and contribute to the understanding of the function of non-promoter differentially methylated regions. Overall design: Biological quadruplicates of both the HCT116 and DKO cell lines were subjected to polyA-site sequencing. Less...