Circular RNA circVAPA Promotes Cell Proliferation in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common malignancy in liver and is one of the leading causes of cancer-induced deaths all over the world. Circular RNAs (circRNAs) have been proven to be related to cancer initiation and progression in mounting reports. However, research on the role of circRNAs in human cancers, including HCC, is still in its infancy. circVAPA has been unmasked as oncogenic in colorectal cancer. Yet the function of circVAPA in HCC has never been elucidated. circVAPA, miR-377-3p, and prosaposin (PSAP) mRNA expression levels were detected by real-time quantitative PCR. PSAP protein levels were measured by Western blot. Cell proliferation was evaluated by CCK-8, colony formation, and EdU assays. Binding capacity was assessed by dual-luciferase reporter assay. circVAPA was upregulated in HCC cell lines and circVAPA depletion was associated with decreased HCC cell proliferation. circVAPA promotes PSAP expression through sequestering miR-377-3p. The suppression of HCC cell proliferation caused by circVAPA silence was revived by PSAP overexpression. This study revealed that circVAPA contributes to HCC cell proliferation through sponging miR-377-3p and thereby disinhibiting PSAP, shedding light on a new insight into HCC initiation and progression.