Objective: The aim of this study was to investigate the expression characteristics of circ_0000064 in hepatocellular carcinoma, and to further explore the underlying mechanism.
Patients and methods: Real time quantitative-Polymerase Chain Reaction (qPCR) was used to detect the expression of circ_0000064 in 42 hepatocellular carcinoma tissues and adjacent normal tissues. Meanwhile, the relationship between circ_0000064 expression and clinical indicators, as well as the prognosis of patients with hepatocellular carcinoma, were detected. QPCR was applied to measure circ_0000064 level in hepatocellular carcinoma cell lines as well. Subsequently, the circ_0000064 knockdown model was successfully constructed using lentivirus in hepatocellular carcinoma cell lines. Cell counting kit-8 (CCK-8), colony formation assay, and flow apoptosis were performed to analyze the influence of circ_0000064 on the biological functions of hepatocellular carcinoma cells. The potential mechanism was explored using cell recovery experiments. In addition, the relationship between circ_0000064 and microRNA-143 was finally explored.
Results: QPCR results showed that the expression level of circ_0000064 in hepatocellular carcinoma tissues was remarkably higher than that of adjacent normal tissues, and the difference was statistically significant. Compared with patients with lower expression of circ_0000064, patients with higher expression of circ_0000064 exhibited remarkably higher pathological stage and lower overall survival rate. In vitro experiments demonstrated that the proliferation ability of the cells was remarkably reduced after the transfection of si-circ_0000064, while cell apoptosis ability significantly increased when compared with the NC group. Meanwhile, qPCR results indicated that microRNA-143 expression was negatively correlated with circ_0000064 expression in hepatocellular carcinoma. Luciferase reporter gene assay indicated that circ_0000064 could be targeted by microRNA-143 through their binding site. In addition, the cell recovery experiment confirmed that circ_0000064 and microRNA-143 could be mutually regulated, which affected the malignant progression of hepatocellular carcinoma together.
Conclusions: Circ_0000064 level was remarkably upregulated in hepatocellular carcinoma and was associated with high pathological stage and poor prognosis of patients. In addition, circ_0000064 significantly promoted proliferation and inhibited apoptosis of hepatocellular carcinoma cells via modulating microRNA-143.