Circular RNA circ_0010235 sponges miR-338-3p to play oncogenic role in proliferation, migration and invasion of non-small-cell lung cancer cells through modulating KIF2A

BACKGROUND: Circular RNA microarray analysis showed hsa_circ_0010235 (circ_0010235) was highly upregulated in non-small-cell lung cancer (NSCLC) patients; however, its role in carcinogenesis and development of NSCLC cells was unrevealed. Here, we intended to investigate role and mechanism of circ_0010235 in NSCLC proliferation, migration and invasion. METHODS AND RESULTS: Expression of circ_0010235, microRNA (miR)-338-3p and kinesin family member 2A (KIF2A) was detected by quantitative real-time PCR, western blotting and immunohistochemistry (IHC). Cell progression was measured by cell-counting kit-8 assay, 5-ethynyl-2-deoxyuridine (EdU) assay, flow cytometry, transwell assay, western blotting, IHC and xenograft experiment. The relationship among circ_0010235, miR-338-3p and KIF2A was determined by dual-luciferase reporter assay, RNA immunoprecipitation and Pearson’s correlation analysis. Expression of circ_0010235 was increased in human NSCLC tissues and cells, accompanied with miR-338-3p downregulation and KIF2A upregulation. Essentially, circ_0010235 could sponge miR-338-3p via target binding, and miR-338-3p downstream targeted KIF2A. Functionally, exhaustion of circ_0010235 induced apoptosis rate of NSCLC cells and curbed cell viability, EdU incorporation, migration rate and invasion rate, accompanied with higher E-cadherin and lower N-cadherin expression. Additionally, re-expression of miR-338-3p prompted above similar effects in NSCLC cells in vitro. Contrarily, miR-338-3p blockage partially counteract the effects of circ_0010235 exhaustion; plus, restoration of KIF2A could attenuate miR-338-3p role, as well. Notably, interfering circ_0010235 delayed tumour growth of NSCLC cells by promoting miR-338-3p and E-cadherin expression, and depressing KIF2A, ki-67 and N-cadherin expression. CONCLUSIONS: circ_0010235 could be a novel identified oncogenic circRNA in NSCLC, and targeting miR-338-3p/KIF2A axis was one regulatory mechanism underlying circ_0010235. KEY MESSAGE: Circ_0010235 was an upregulated circRNA in NSCLC patients and cells. Interfering circ_0010235 restrained NSCLC cell proliferation and metastasis in vitro and in vivo. miR-338-3p per se suppressed NSCLC in vitro and its downregulation diminished the tumour-suppressive role of circ_0010235 blockage in NSCLC cells. miR-338-3p could downstream target KIF2A and be sponged by circ_0010235.