SRP310070 PRJNA712993 GSE168602 Gene expression profiling during treatment of COLO205 cells with selumetinib Here, we investigate gene expression response of the BRAFV600E mutant cell line COLO205 to the MEK inhibitor selumetinib / AZD6244 / ARRY-142886. Although selumetinib causes long term G1 arrest, we observe cells stochastically entering the cell cycle without re-activation of ERK and initiation of a normal proliferative gene expression programme. Genes encoding DNA replication and repair factors are downregulated during G1 arrest, but many of these are transiently induced when cells escaping arrest enter S and G2. Nonetheless, mRNAs encoding key DNA replication factors including the MCM replicative helicase complex, PCNA and TIPIN remain at very low abundance. Overall design: 1) An mRNA-seq timecourse of COLO205 cells across 48 hours selumetinib treatment. 2) COLO205 cells either untreated or treated 24 hours with 1 µM selumetinib were glyoxal fixed and stained for CCNB1 then flow sorted into CCNB1 positive and CCNB1 negative fractions, RNA extracted and mRNA-seq performed. Equivalent cell populations were pulsed for 4 hours with EdU, stained and sorted into EdU negative and positive cohorts that were then used for mRNA-seq. GSE168602 pubmed 36267209 parent_bioproject PRJNA712989