CircRNA-PTN Sponges miR-326 to Promote Proliferation in Hepatocellular Carcinoma

BACKGROUND: Mounting evidences reveal that circular RNAs (circRNAs) are critical to regulate biological behavior and process of tumor. Our objective is to explore the role of circRNA-PTN (circPTN) and explain the exact mechanism in hepatocellular carcinoma (HCC). METHODS: Real-time polymerase chain reaction assay was used to detect the level of circPTN and miR-326. The proliferation of cell was measured by CCK-8 assay and EdU assay. Western blot assay was performed to assess ErbB/PI3K expression. Luciferase and RNA pull-down assays were carried out to confirm the interaction between circPTN and miR-326. RESULTS: Our results indicated that circPTN was upregulated in human hepatocellular carcinoma tumor tissues and cell lines, compared with paratumor tissues and immortalized normal liver cell line. circPTN could significantly promote HCC tumor growth according to gain-and loss-of-function assays. Additionally, we determined that circPTN acted as a sponge through interacting with miR-326. Overexpression of miR-326 could rescue the cell proliferation inhibition and ErbB/PI3K downregulation in HCC cells by circPTN. Besides, the effects of miR-326 on HCC were missing when circPTN binding sites were mutated. CONCLUSION: Our study indicates that circPTN acts as an oncogenic factor via sponging miR-326 in HCC.