Protein kinase N1 promotes proliferation and invasion of liver cancer

Protein kinase (PK) N1, also called PKC-related protein 1, participates in the proliferation, invasion and metastasis of various malignant tumors. However, the role of PKN1 in liver cancer remains to be elucidated. The present study investigated the expression of PKN1 using immunohistochemistry in surgical specimens from 36 patients and analyzed the correlation with VEGF, microvascular density (MVD), cell proliferation index (Ki67) and clinicopathological parameters. PKN1 was highly expressed in hepatocellular carcinoma (HCC) and was positively correlated with histological grading of HCC, Ki67 expression and MVD. PKN1 expression in moderately and poorly differentiated HCC was significantly higher compared with highly differentiated HCC. Expression of PKN1 was positively correlated with Ki67 and MVD, and Ki67 expression was positively correlated with MVD. The effects of PKN1 on proliferation, invasion and apoptosis of liver cancer cells were detected in vitro. Cell viability, migration and invasion were reduced and the apoptosis rate was significantly improved when PKN1 expression was silenced in liver cancer cells. Thus, PKN1 serves an important role in the development and progression of liver cancer. Inhibition of PKN1 activity may provide a promising therapeutic target for liver cancer.