miR-570 Inhibits Proliferation,Angiogenesis,and Immune Escape of Hepatocellular Carcinoma

Abstract

Hepatocellular carcinoma (HCC) is one common malignancy. The authors previously demonstrated that miR-570 regulates the development of HCC. This study detected the effect of miR-570 on cell apoptosis, angiogenesis, T cell activation, and proliferation in a tumorigenicity assay in nude mice. miR-570 mimics and negative control (NC) were transfected into SMMC7721 cells, and then, the cells were subcutaneously injected in the right flank in nude mice. Six weeks later, the dissected tumors and peripheral blood were collected. Tumor weight and volume were measured, and expression of miR-570 and apoptosis-related gene Bax/Bcl-2 was detected by quantitative real-time polymerase chain reaction. Hematoxylin and eosin, immunohistochemistry of CD31 and vascular endothelial growth factor (VEGF), TUNEL assay, and flow cytometry detection of CD4 and CD8 in peripheral blood were performed. miR-570 mimics suppressed tumor growth compared with the NC, with decreases in tumor weight and tumor volume. Very few CD31 and VEGF were found in tumor sections in miR-570 mimics group. Bax level was significantly increased, while Bcl-2 level was significantly downregulated. Significant lower ratio of CD3⁺CD4⁺ T cells and higher ratio of CD8⁺IFN-γ⁺ T cells were found in peripheral blood and tumor tissues in miR-570 mimics than NC. Collectively, miR-570 plays an important role in the proliferation, angiogenesis, and immune escape of HCC, which might be potential diagnostic and predictive biomarkers.