Protein phosphatase magnesium-dependent 1δ is a novel tumor marker and target in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a lethal liver malignancy worldwide. In this study, we reported that protein phosphatase magnesium-dependent 1δ (PPM1D) was highly expressed in the majority of HCC cases (approximately 59%) and significantly associated with high serum α-fetoprotein (AFP) level ( P = 0.044). Kaplan- Meier and Cox regression data indicated that PPM1D overexpression was an independent predictor of HCCspecific overall survival (HR, 2.799; 95% CI, 1.346–5.818, P = 0.006). Overexpressing PPM1D promoted cell viability and invasion, whereas RNA interference-mediated knockdown of PPM1D inhibited proliferation, invasion, and migration of cultured HCC cells. In addition, PPM1D suppression by small interfering RNA decreased the tumorigenicity of HCC cells in vivo . Overall, results suggest that PPM1D is a potential prognostic marker and therapeutic target for HCC.