miR-126-5p enhances radiosensitivity of lung adenocarcinoma cells by inhibiting EZH2 via the KLF2/BIRC axis

Radiotherapy is a common method for the treatment of lung adenocarcinoma, but it often fails due to the relative non-susceptibility of lung adenocarcinoma cells to radiation. We aimed to discuss the related mechanisms by which miR-126-5p might mediate radiosensitivity of lung adenocarcinoma cells. The binding affinity between miR-126-5p and EZH2 and between KLF2 and BIRC5 was identified using multiple assays. A549 and H1650 cells treated with X-ray were transfected with miR-126-5p mimic/inhibitor, oe-EZH2, or si-KLF2 to detect cell biological functions and radiosensitivity. Finally, lung adenocarcinoma nude mouse models were established. miR-126-5p and KLF2 were poorly expressed, while EZH2 and BIRC5 were upregulated in lung adenocarcinoma tissues and cells. miR-126-5p targeted EZH2 to promote the KLF2 expression so as to inhibit BIRC5 activation. Both in vitro and in vivo experiments verified that elevated miR-126-5p inhibited cell migration and promoted apoptosis to enhance the sensitivity of lung adenocarcinoma cells to radiotherapy via the EZH2/KLF2/BIRC5 axis. Collectively, miR-126-5p downregulated EZH2 to facilitate the sensitivity of lung adenocarcinoma cells to radiotherapy via KLF2/BIRC5.