Transcriptome and translatome profiling of MCF7 vector cells after p53 activation

Several genome-wide transcriptome analyses that focused on p53-induced cellular responses in many cellular contexts have continued to expand the already vast p53-regulated transcriptional networks. To investigate post-transcriptional controls as an additional dimension of p53-directed gene expression responses we performed translatome analysis by polysomal profiling on MCF7 cells treated with Doxorubicin and Nutlin-3a. A comparison between the transcriptome and the translatome revealed a large number of uncoupled genes, whose transcription changes did not correlate with translation changes. Overall, we establish p53 as a master regulator of translational control and identify many p53 target genes affecting translation that can contribute to p53-dependent cellular responses. Keywords: p53, transcriptome, translatome, polysomal RNA, subpolysomal RNA, uncoupling, Doxorubicin, Nutlin-3a Total RNA (tot) was extracted from MCF7 vector cells after 16h of treatment with Doxorubicin (1.5uM) and Nutlin-3a (10uM) or DMSO (solvent, as control treatment). Polysomal profiling was performed after the same conditions. We collected all subpolysomal mRNA fractions (sub) and the polysomal ones (pol) after sucrose gradient fractionation of cytoplasmic lysates to analyze separately mRNAs that are not actively translated from those that are considered in active translation, respectively. Experiments were performed in three biological replicates.