Knockdown of circular RNA UBAP2 inhibits the malignant behaviours of esophageal squamous cell carcinoma by microRNA-422a/Rab10 axis.

Esophageal squamous cell carcinoma (ESCC) is a major type of esophageal cancer, accounting for about 90% of cases. Circular RNA UBAP2 (circUBAP2) is involved in the progression of several types of cancers. However, the role of circUBAP2 in ESCC remains unclear. In the present study, circUBAP2 expression was found to be upregulated in ESCC tumour tissues. Knockdown of circUBAP2 through infection with lentiviral vector encoding shRNA targeting circUBAP2 (sh-circUBAP2) inhibited the proliferation, migration and invasion of ESCC cells. In addition, circUBAP2 significantly promoted the proliferation, migration and invasion of ESCC cells. In vivo xenograft assay demonstrated that circUBAP2 downregulation suppressed the tumour growth of ESCC. Further mechanism investigations proved that circUBAP2 exerted its role via sponging microRNA (miR)-422a, and miR-422a directly targeted Rab10 in ESCC cells. These findings suggested that circUBAP2 acted as oncogene through regulating the miR-422a/Rab10 axis in ESCC.