Chronology of DNA methylation changes through transformation stage leading to senescence by-pass in Syrian hamster fetal primary cells exposed to benzo[a]pyrene

Purpose: To use reduced representaion bisulfite sequencing to measure differential genome methylation among: 1. cells treated with benzo[a]pyrene (B[a]P) versus vehicle alone (DMSO) using the Syrian Hamster Cell Transformation Assay method; 2. cells originating from normal (Nc) versus morphologically transformed (MTc) colonies; 3. cells in senescence (SEN) versus those that have bypassed senescence (SENbp). Overall design: Reduced representation bisulfite sequencing was performed to measure cytosine methylation within genomic DNA. Four biological replicates were sampled to study B[a]P versus untreated colonies (DMSO) and MT versus N colonies. Four technical replicates were sampled to study senescence versus senescence-bypass. All cells were confirmed male using a rapid XY qPCR assay.