Serum Reponse Factor (SRF) is a transcriptional activator of Mouse Double Minute 4 (MDM4) in hepatocellular carcinoma

The Mouse Double Minute 4 (MDM4) represents a p53-binding protein acting as a transcriptional repressor. We have previously demonstrated that both MDM4 mRNA and protein levels are upregulated in about 50% of human hepatocellular carcinomas (HCC). Although we identified 1q32 gains as a mechanism leading to MDM4 overexpression in human HCC, many liver tumors show a balanced MDM4 gene locus, but high MDM4 mRNA levels. Thus, we hypothesized that dysregulated transcription may account for the high MDM4 expression observed in human liver tumors. Here, we show that overexpression of the Serum Reponse Factor (SRF) is in…