Circular RNA circ_0026134 regulates non-small cell lung cancer cell proliferation and invasion via sponging miR-1256 and miR-1287

Non-small cell lung cancer (NSCLC) is the major type of lung malignancy with increasing incidence worldwide. Despite progression in diagnosis and management of NSCLC, the patients' survival rate is still unfavorable. Accumulating data have shown that circular RNAs (circRNAs) act as key roles in oncogenesis. In this project, circ_0026134 expression in NSCLC tissue specimens and cells was measured by RT-qPCR. The functional roles (cell growth, apoptosis, migration, and invasion) of circ_0026134 were investigated by gain and loss-of-function assays. In addition, luciferase reporter assay was used to uncover the mechanisms of circ_0026134. Circ_0026134 was frequently upregulated in NSCLC samples and cell lines. Furthermore, we observed that downregulation of circ_0026134 attenuated NSCLC cell proliferation and metastatic properties and induced cell apoptosis. The overexpression of circ_0026134 in NSCLC cells caused the opposite effect. For the part of mechanism exploration, miR-1256 and miR-1287 were proved to be sponged by circ_0026134. Rescue experiments further indicated that the oncogenic role of circ_0026134 was dependent on its regulation of miR-1256 and miR-1287. Taken together, this study may provide a new insight and treatment target for NSCLC.