Epigenetic and genetic change through cell cycling under selumetinib treatment

Here we apply single cell bisulfite sequencing to detect epigenetic and genetic changes that occur in BRAF V600E cells that escape G1 arrest and return to the cell cycle during treatment with the MEK inhibitor selumetinib. We detect no major changes in DNA methylation, but find that cells in G2 are enriched in large amplifications and deletions that we ascribe to abnormal mitotic chromosome segregation. COLO205 cells were treated with 1uM selumetinib for 48 hours then fixed with glyoxal and stained for cyclin B1. 48 cyclin B1 negative and 48 positive cells were sorted into individual wells and subjected to a standard single cell bisulfite sequencing protocol.