Midnolin Regulates Liver Cancer Cell Growth In Vitro and In Vivo

Hepatocellular carcinoma (HCC) ranks worldwide as one of the most lethal cancers. In spite of the vast existing knowledge about HCC, the pathogenesis of HCC is not completely understood. Discovery of novel genes which contribute to HCC pathogenesis will provide new insights for better understanding and treating HCC. The relatively obscure gene midnolin has been studied for over two decades; however, its biological roles are largely unknown. Our study is the first to demonstrate the functional significance of midnolin in HCC/cancer: Midnolin expression correlates with poor prognosis in HCC patients, and suppression of midnolin severely inhibits tumorigenicity of HCC cells in vitro and in mice and disrupts retinoic acid/lipid metabolism in these cells. Overall design: In order to investigate the role of midnolin in HCC, we generated midnolin knockdown (KD) Hepa1-6 stable cell line by transduction of lentivirus containing shRNA targeting midnolin, and then we evaluated the effect of midnolin KD on cell proliferation, colony formation, and tumor formation.