Objective To establish the nude mice model of non-small cell lung cancer(NSCLC)H460 cell to investigate the combined effects of radiotherapy and celecoxib.

Methods Athymic mice bearing H460 were randomly divided into 4 groups:control, radiotherapy, celecoxib and radiotherapy plus celecoxib group. The administration dose of celecoxib was 16 mg·kg^-1·d^-1. The mice were treated with radiotherapy 2 hours after administration and the fractionated dose was 5 Gy, 2 fractions per week. Mice were killed to detect tumor weight 4 weeks after treatment. The expression levels of ataxia telangiectasis mutated(ATM)and epidermal growth factor receptor(EGFR)in tumor tissues were detected by immune-histochmical method.

Results The tumor weight in control, radiotherapy, celecoxib and radiotherapy plus celecoxib group were(133.62±12.37), (130.37±12.59), (81.17±8.29) and (35.51±4.23)mg respectively. There was significant difference between the radiotherapy plus celecoxib group and the radiotherapy group(t=5.41, P < 0.01). The expression levels of ATM and EGFR in the radiotherapy plus celecoxib group were significantly lower than that in radiotherapy group(t=4.23 and 3.17, both P < 0.01).

Conclusions Celecoxib promotes radiotherapeutic sensitivity of H460 by down-regulating the expression levels of ATM and EGFR. Celecoxib may presents potency in curing human lung cancer.