Nek7 is overexpressed in hepatocellular carcinoma and promotes hepatocellular carcinoma cell proliferation in vitro and in vivo

NIMA-related kinase-7 (Nek7) is a serine/threonine kinase involved in cell-cycle progression via mitotic spindle formation and cytokinesis. In this study, we investigated whether Nek7 involves in hepatocellular carcinoma (HCC). Interestingly, we found that Nek7 was significantly overexpressed in HCC than in liver tissues. In HCC patients, high Nek7 expression was significantly correlated with tumor numbers, tumor diameter, adjacent organs invasion, tumor grade and TNM stage. Furthermore, Nek7 expression pattern showed close relationship with that of Ki-67, a well-stablished cell proliferation marker. More importantly, patients with higher expression levels of Nek7 had significantly lower 5-years survival rate. Likewise, Nek7 expression was significantly higher in HCC cell lines than normal hepatic cell line. By Nek7 silencing using lentivirus-mediated Nek7 interference approach, the growth of HCC cell lines was inhibited and the tumor growth in xenograft mouse model was also suppressed. Mechanistic studies showed that silencing of Nek7 resulted in decreasing cyclinB1 level both in vitro and in vivo. In conclusion, this study highlights for the first time the possible role of Nek7 in HCC progression. Nek7 would be a useful biomarker that early predicts HCC patients at higher risk of poor prognosis. Also, Nek7 could be a novel HCC therapeutic target.