Overexpression of CASC2 Improves Cisplatin Sensitivity in Hepatocellular Carcinoma Through Sponging miR-222

The long noncoding RNA cancer susceptibility candidate 2 (CASC2) has been shown to play a crucial role in cancer cell chemoresistance. However, its function and underlying molecular mechanism in hepatocellular carcinoma (HCC) chemoresistance remain unknown. In this study, we used cisplatin (DDP)-resistant HCC cells to investigate CASC2 function and its underlying mechanism. The results demonstrated that CASC2 expression was significantly reduced in HCC tissues and cells, especially in DDP-resistant HCC tissues and cells. Lower CASC2 expression was strongly correlated with shorter survival times in patients with HCC. Functionally, CASC2 overexpression sensitized DDP-resistant Huh7/DDP and SMMC-7721/DDP cells to DDP. Mechanically, CASC2 improved the sensitivity of HCC cells to DDP through sponging miR-222. Taken together, these findings suggested that overexpression of CASC2 overcame DDP resistance in HCC by regulating miR-222 expression, thereby providing a potential therapeutic strategy for overcoming HCC cell chemoresistance.