MiR-381 enhances the sensitivity of non-small cell lung cancer to radiotherapy by targeting ROCK2 to regulate NF-κB signaling pathway

Abstract

BackgroundWe investigated the effect of miR-381 on the sensitivity of non-small cell lung cancer (NSCLC) to radiotherapy, and examined its possible mechanism.MethodsNSCLC A549 cells and miR-381 overexpression and gene silencing cell lines were treated with radiotherapy. The cell proliferation was tested by CCK-8 assay and colony formation. Flow cytometry and TUNEL were used to detect the cell apoptosis. The expression of nuclear factor kappa B (NF-κB) signaling pathway related proteins were detected by western blot. NF-κB signaling pathway activator and inhibitor cell lines were further constructed and the above experiments were repeated. Double luciferase assay was used to verify the target of miR-381. Furthermore, a nude mouse xenograft model was constructed and treated with radiotherapy. The tumor volume and tumor weight were measured. The expression of PCNA protein in tumor tissues was observed by immunohistochemistry. The apoptosis related proteins in tumor tissues were detected by western blot.ResultsThe mRNA expression of miR-381 was increased after radiotherapy treatment. Radiotherapy treatment also can inhibit the proliferation and promote apoptosis of A549 cells. Compared with radiotherapy group, cell proliferation was significantly decreased and apoptosis was significantly increased in miR-381 overexpression group (p < 0.05). Moreover, ROCK2 is a target of miR-381, and overexpression of miR-381 can down-regulate the expression of ROCK2 protein. In nude mice, miR-381 mimic interference can reduce cell tumorigenicity and proliferation, and increase the apoptosis. However, the indicators above were contrary in miR-381 silencing group. Verification experiments further verify that NF-κB signaling pathway activator can reverse the role of miR-381.ConclusionMiR-381 overexpression could enhance the sensitivity of NSCLC to radiotherapy by targeting ROCK2 to inhibit NF-κB signaling pathway.