Circ-PAX2 promotes proliferation and metastasis by absorbing miR-186 in lung cancer cells.

Circ-RNAs are a type of non-coding-protein RNAs which act as an effector role in many physiological processes. However, the novel function of circ-PAX2 in lung carcinomas is still unidentified. The current study is to detect the expression of circ-PAX2 in lung squamous cell carcinoma (LSCC) tissues and the physiological functions of circ-PAX2. Circ-PAX2 was distinguished in LSCC samples and matched non-tumor samples by human circRNA microarray analysis and was validated to be up-regulated in 86 specimens of LSCC tissues and lung cancer cell lines by qRT-PCR. Functional validation experiments showed that knockdown of circ-PAX2 promoted apoptosis of lung carcinoma cells, and then suppressed proliferation and migration of tumor cells. Small interfering RNA (siRNA) to circ-PAX2 inhibited growth in lung tumor cells. Bioinformatics prediction and rescue experiments showed that circ-PAX2 was a target of microRNA-186, confirmed by qRT-PCR and double luciferase reporter assay. On the whole, our findings reveal that circ-PAX2 was up-regulated and may be an oncogene in lung cancer; its function was reducing apoptosis, promoting cell proliferation and migration in lung carcinoma cells, which might be a novel therapeutic targetgene in lung cancer.