The effect of rapamycin upon the enhancer landscape in the context of replicative senescence

ChIPs of the histone modifications H3K27ac and H3K4me2, which mark enhancers and promoters, were examined during the course of replicative senescence in BJ fibroblasts that were grown in the presence or absence of rapamycin. Overall design: BJ fibroblasts were cultured in the presence or absence of rapamycin and were collected at young-quiescent, intermediate-quiescent, and senescent stages, at which point chromatin was harvested and prepared for ChIP-seq the histone marks H3K27ac and H3K4me2. The ChIP-seq tag density of various enhancer regions were compared between different cell stages as well as between rapamycin treatment and non-treatment. These fold changes in tag density were compared between marks to determine which enhancers showed consistent changes in activation in both histone modifications