The Synergistic Effect Of Celecoxib And Gefitinib In Non–small Cell Lung Cancer Cells

Objective:Gefitinib was combined with celecoxib to investigate the efficacy of inhibition in vitro in two NSCLC cell lines: HCC827(del E746-A750) and A549(wild-type EGFR). The cells were treated with gefitinib or celecoxib alone or with gefitinib plus celecoxib. Cell proliferation and apoptosis were assessed and correlated with expression of COX-2 and phosphorylated(p)-EGFR.Methods: MTT was used to measure the growth inhibitory effects of two cells by Gefitinib and Celecoxib treated with drugs fo r48 hours. The cell apoptosis was studied by flow cytometric analysis. The expression of p-EGFR and COX-2 were determined by western blot. All the data above were expressed byx±S, and were analyzed using analysis of variance, with SPSS17.0 software. The statistic significance were defined as P<0.05.Results:1. Cell vigor detected by methyl thiazolyl tetrazolium(MTT): Celecoxib and gefitinib inhibited cell growth in both cell lines. At sufficiently high concentrations, celecoxib plus gefitinib significantly mutually enhanced their anti-proliferative effects in both cell lines. At low concentrations, the combination had no additional effects on A549 cells.2. The apoptosis rate treated by drugs: Annexin V/PI method showed that: in HCC827 cells the early apoptosis rate in the control group was(0.26±0.10)%, the apoptosis rate of the combined group was(39.22±3.67)%, significantly higher than Gefitinib(10umol/L) or celecoxib(10umol/L) alone, whose apoptotic rate was respectively(9.71±0.94)% and(21.54±1.98)%. However, in A549 cells the apoptosis of the combination had no additional effects at low concentrations. But at high concentration, the apoptosis rate of the combined group was(25.91±4.08)%, significantly higher than Gefitinib(40umol/L) or celecoxib(80umol/L) alone, whose apoptotic rate was respectively(6.30±1.02)% and(18.46±1.92)%.3. The expression of p-EGFR and COX-2 were determined by western blot: There was increased down regulation of COX-2 and p-EGFR when both cell lines were treated with high-concentration celecoxib plus gefitinib compared to either agent alone.Conclusion:1. The efficacy of combined celecoxib and gefitinib is significantly greater in HCC827 cells with EGFR mutations.2. The efficacy of combined celecoxib and gefitinib is significantly greater at high concentrations in A549 cells.3. Blocking EGFR and COX-2 simultaneously synergistically reduce the level of p-EGFR and COX-2.