Abstract

MacroH2A is an histone variant implicated in transcriptional repression. During development and differentiation, macroH2A1 and macroH2A2 isoforms become enriched in the chromatin fraction creating an epigenetic barrier to somatic cell reprogramming towards pluripotency. I therefore hypothesize that macroH2A may act as global repressor that is evicted from chromatin not only in the reprogramming process, but also during breast cancer progression. Currently, we are investigating macroH2A, H3K27me3, and H3K27ac genomic occupancy by ChIP-seq in both normal and tumorigenic cell lines to dissect the chromatin-mediated mechanisms by which loss of macroH2A renders cells more tumorigenic.