circVAPA promotes the proliferation, migration and invasion of oral cancer cells through the miR-132/HOXA7 axis

Objective To study the relationship between the circular RNA vesicle-associated membrane protein-associated protein A (circVAPA) and the pathogenesis of oral squamous cell carcinoma. Methods The expression of circVAPA was detected by RT-qPCR. In vitro loss-of-function experiments were performed in Cal-27 cells. The malignant phenotype of cells was evaluated by cell counting kit-8, clone formation and transwell assays. Luciferase reporter assays were used to assess the circVAPA/miR-132/homeobox A (HOXA) regulatory axis. Results circVAPA expression was significantly increased in oral cancer tissues and cells. The overall survival and progression-free survival of patients with oral cancer who exhibited high circVAPA expression were significantly shorter compared with those with low expression. circVAPA expression was closely related to tumor size, TNM stage and distant metastasis. circVAPA knockdown reduced the proliferation, invasion and migration of Cal-27 cells. MiR-132 was identified as a target of circVAPA in Cal-27 cells. Cotransfection with si-circVAPA and miR-132 inhibitor reversed the inhibitory effect of circVAPA knockdown on cell malignant phenotypes. HOXA7 was further identified as a downstream target of miR-132. Conclusion circVAPA is highly expressed in oral cancer, and its abnormal expression might affect the proliferation, invasion and migration of oral cancer cells by modulating the miR-132/HOXA7 signaling axis.