High Expression of Proline-Rich Tyrosine Kinase2 is Associated with Poor Survival of Hepatocellular Carcinoma via Regulating Phosphatidylinositol 3-Kinase/AKT Pathway

Background The peritumoral environment has been implicated to be important in the process of metastasis and recurrence in hepatocellular carcinoma (HCC). Our aims were to assess the prognostic value of proline-rich tyrosine kinase 2 (Pyk2) in HCC and investigate related molecular mechanism. Methods Expression of Pyk2 was tested by immunohistochemistry in tissue microarrays containing 141 paired HCC samples. Correlation between Pyk2 and vascular endothelial growth factor (VEGF) expression in clinical samples was analyzed by Spearman rank correlation. Matrigel invasion, anchorage-independent growth assay and immunoblotting were performed to study the effect of Pyk2 on the invasion and progression of HCC cells and phosphoinositide 3-kinase (PI3K)/AKT pathway activation. Results Higher Pyk2 density in both tumor and peritumor was associated with lower overall survival ( P = 0.044; P = 0.041, respectively), serum AFP levels > 1,000 ng/ml ( P = 0.013; P = 0.032, respectively) and postoperative distant metastasis (both P