Effect of MITF depletion on gene expression in U2OS cells

Summary (abstract): The transcriptional factor MITF is a central regulator of melanocytes and plays an important role in melanoma. In melanocytes MITF regulates the transcription of large number of genes with approximately 500 genes as validated targets. Functionally, MITF target genes are quite diverse including genes involved in pigmentation, DNA damage response, mitotic regulation, and DNA replication. Considering the transcriptional regulation of genes involved in non-melanocyte specific processes and the fact that MITF is expressed across tissue types, raises the question of whether the role of MITF outside the melanocyte lineage might be underestimated. Our data shows that in the osteosarcoma cell line, significant number of genes involved in DNA replication, DNA repair and mitotic regulation are downregulated upon MITF depletion, suggesting that the protein might be vital to maintain genome stability in the cell line. Overall design: All samples underwent RNAi treatmend, where control replicates were treated with a negative control (SiControl) and experimental replicates were were treated with an siRNA which targeted the MITF gene (SiMITF). Each sample except the ones marked UT (untreated) were also treated with 50ng/ml NCS (Neocarzinostatin)to induce Double stranded breaks.