TPX2 Is a Prognostic Marker and Contributes to Growth and Metastasis of Human Hepatocellular Carcinoma

Targeting protein for Xenopus kinesin-like protein 2 (TPX2), a microtubule-associated protein, impacts spindle assembly in human cells. Several studies have demonstrated that TPX2 is overexpressed in different types of human cancers and promotes tumor growth and metastasis. In this study, we found that the expression level of TPX2 was obviously higher in hepatocellular carcinoma (HCC) tissues than in matched nontumor tissues. Elevated expressions of TPX2 mRNA were observed in all HCC cell lines (HepG2, Hep3B, SMMC-7721, Bel-7402 and Huh7) as compared with that in a non-transformed hepatic cell line (LO2). Clinical analysis indicated that the positive expression of TPX2 was significantly correlated with venous infiltration, high Edmondson-Steiner grading and advanced TNM tumor stage in HCC. Furthermore, TPX2 was a novel prognostic marker for predicting 5-year overall survival (OS) and disease-free survival (DFS) of HCC patients. In vitro studies found that TPX2 knockdown significantly inhibited cell proliferation and viability in both Hep3B and HepG2 cells. Moreover, TPX2 knockdown obviously slowed down tumor growth in a nude mouse xenograft model. Otherwise, TPX2 knockdown prominently suppressed HCC cell invasion and migration. In conclusion, these results indicate that TPX2 may serve as a prognostic marker and promotes tumorigenesis and metastasis of HCC.