Mapping putative regulatory regions using Histone H3 Lysine 4 monomethylation marks in breast cancer cell lines.

Breast cancer is the most frequently diagnosed cancer in women. In cancer, tumour cells accumulate changes over time that allow them to replicate indefinitely. These changes can be mutations to DNA and also epigenetic modifications. This study looks at a histone modification, H3K4me1, in multiple breast cancer cell lines. It has been found that the regions between flanking H3K4me1 peaks, referred to as "valleys", are enriched for bound transcription factors. Multiple cell lines were used to form functional groups (luminal vs. basal cell lines and tumourigenic vs. a non-tumourigenic match control) in which to look for concordance of valleys. In addition, overexpressed genes in a functional group, as determined by RNA-seq, were correlated with associated uniquely marked valleys. A motif analysis was done on the valley sequences using MEME and STAMP to yield putative transcription factor binding sites. This analysis yielded some known and putative tumour suppressors and oncogenic factors.