Knockdown of RNF2 enhances radiosensitivity of lung squamous cell carcinoma cells

A previous study has reported that RING finger protein 2 (RNF2) knockdown increases radiosensitivity of esophageal cancer cells both in vitro and in vivo. However, the effect of RNF2 knockdown on radiosensitivity in squamous cell carcinoma (SqCC) remains unknown. NCI-H226 and SK-MES-1 cells were exposed to X-ray irradiation and then RNF2 levels were determined. RNF2 was knocked down and stable transfectants were selected. Radiosensitivity, cell proliferation, apoptosis, cell cycle and γ-H2AX foci formation were evaluated. Interaction among ataxia telangiectasia mutated protein (ATM), mediator of DNA damage checkpoint 1 (MDC1) and H2AX was examined. Xenograft models were used to explore the effect of RNF2 knockdown on radiosensitivity in vivo. The results showed that RNF2 expression was significantly increased by X-ray irradiation. RNF2 knockdown combined with X-ray irradiation markedly inhibited cell proliferation, caused cell cycle arrest at G1 phase and induced cell apoptosis. In addition, RNF2 knockdow...