Abnormal expression of Wnt3a and inhibiting role of its molecular-targeted intervening in hepatocellular carcinoma

Abstract

Objective: To investigate the Wnt3a expression in tissues of HCC and its gene knockout on effects of HepG2 cell proliferation or xenograft tumor growth. Methods: Hepatic Wnt3a expressions in 87 HCC and their matched surrounding tissues were observed by tissue microarray and immunohistochemistry for analyzing its clinicopathological characteristics; Wnt3a-knockout HepG2 cell lines were established by Crispr/cas9-sgRNA system and genomic cleavage efficiency was verified at gene level by surveyor assay. The relative proteins were confirmed by Western blotting; Cell Counting Kit-8 assay was used to examine cell proliferation after knocking-out Wnt3a successfully, and the nude mice HepG2 cell xenograft tumors delete that the relationship between Wnt3a and HCC growth. Results: The positive Wnt3a with brown staining particles was mainly distributed in cytosol and membrane of hepatocytes. The incidence of hepatic Wnt3a expression in cancerous tissues (95.4%) was significantly higher (χ (2) = 47.754, P < 0.001) than that in their surrounding tissues (49.4%). The high Wnt3a expression was 70.1% in the HCC and only 14.9% in the surrounding tissues. High Wnt3a expression was associated with poorly-differentiated grade, liver cirrhosis, HBV infection, portal vein invasion, TNM stage and 5-year survival rate. After knocked-out by Crispr/cas9-sgRNA system successfully, Wnt3a expression was down-regulated significantly at gene or protein level. Key molecule β-catenin in cytoplasma was obviously inhibited. HepG2 cell lines proliferation was suppressed in time-dependent manner. The nude mice HepG2 cell xenograft tumors confirmed that the knock-out of Wnt3a could significantly supressed HCC growth with slower speed (t = 6.418, P < 0.001), smaller volume(869.4 ± 222.5 mm(3) vs 355.0 ± 99.9 mm(3), t = 5.168, P < 0.001), and lighter weight (0.88 ± 0.20 g vs 0.35 ± 0.11 g, t = 5.628, P < 0.001)compared with the control group. Conclusion: Abnormal expression of Wnt3a could be expected as a promising target for HCC gene therapy.