Transcriptome profiling of MDA-MB-231 cells following the MEL-18 phosphorylation at T334

RNA-sequencing analysis of MEL-18 WT- or MEL-18 T334A-overexpressing MDA-MB-231 cell lines. MEL-18, a core component of polycomb-repressive complex (PRC)-1, has been known to be phosphorylated at multiple residues in vitro; however, its functional roles in mammalian cells and human cancer remains largely unknown. Here, we examined the effect of MEL-18 phosphorylation at T334 site on polycomb-mediated epigenetic silencing in human breast cancer. Our results demonstrated that the phosphorylation of MEL-18 at T334 alters its genomic distribution and transcriptional activity that reflects functional change of MEL-18 in modulating breast tumour progression. Overall design: MDA-MB-231 cells stably expressing either MEL-18 wild type (WT) or T334 phosphorylation-deficient mutant form of MEL-18 (MEL-18 T334A) and control cells (CON, empty vector) were cultured in DMEM supplemented with 10% FBS for 48h. Total RNA was isolated from the cultures using Trizol reagent. For each of the 3 conditions, 3 biological replicates were included. In total, 9 RNA-sequencing samples were analyzed; 3 controls, 3 MEL-18 WT, and 3 MEL-18 T334A overexpressing cells.