Selective COX-2 Inhibitor Combined With EGFR-tyrosine Kinase Inhibitor Study On The Growth And Apoptosis Of Non-small Cell Lung Cancer And Its Mechanisms

Objective To explore the effects of COX-2(cyclooxygenase-2)inhibitor Celecoxib combined with EGFR-TKI(epidermal growth factor receptor tyrosine kinase inhibitor)Icotinib on NSCLC(non-small cell lung cancer)in vivo Study on the influence and mechanism of proliferation and apoptosis.Methods The effects of Celecoxib combined with Icotinib on the growth of transplanted tumors in nude mice with A549 cells were first explored in vivo.1.NSCLC that will be purchased into A549 cell transplanted tumor nude mice were randomly divided into four groups and continuously administrated for 28 days:(1)control group: transgastric perfused with 0.9% normal saline solution,(2)Celecoxib group: transgastric perfused with Celecoxib drug solution,(3)Icotinib group:transgastric perfused with Icotinib drug solution,and(4)combination group(Celecoxib + Icotinib): transgastric perfused with Celecoxib drug solution and Icotinib drug solution.2.Observe the general condition of transplanted tumor bearing nude mice during administration,draw the transplanted tumor growth curve of each group.3.The nude mice were sacrificed after the end of administration,and the weight and volume tumor inhibition rates were calculated.4.Calculate the CDI(coefficacy of drug interaction,two drug interaction index)between Celecoxib and Icotinib,with CDI < l,= 1,or > l representing the effect of the two drugs being synergistic,additive,or antagonistic,respectively.Next,we investigated the mechanism of Celecoxib combined with Icotinib on proliferation and apoptosis of transplanted tumor in nude mice bearing A549 cells.5.The apoptosis rate of each group was detected by TUNEL assay.6.Protein expression of PCNA(proliferating cell nuclear antigen),Bcl-2(B-cell lymphoma-2,),COX-2,and EGFR(epidermal growth factor receptor)was determined by immunohistochemistry,and correlations were calculated by Pearson’s method.Results 1.Celecoxib combined with Icotinib could exert inhibitory effects on the growth of transplanted tumors in nude mice with A549 cells,and this effect was synergistic.(1)The growth of transplanted tumors in nude mice in the combination group was slower than that in the Celecoxib,Icotinib,and control groups,and the tumor suppressive rate of tumor volume in the combination group(66.412%)was significantly higher than that in the Icotinib(34.762%)and Celecoxib(29.343%)groups,and the tumor suppressive rate in the combination group(43.986%)was significantly higher than that in the Icotinib(22.251%)and Celecoxib(17.920%)groups,respectively Statistical significance(P <0.05).(2)The CDI value for Celecoxib versus Icotinib was 0.8679.2.Celecoxib combined with Icotinib could promote A549 cell apoptosis.The apoptosis rates measured by TUNEL assay in the combination,Icotinib,Celecoxib and control groups were(52.49± 14.37)%,(40.10 ± 6.97)%,(39.93 ± 7.42)%,(30.76 ± 5.77)%,respectively.The combination group had a higher apoptotic rate than the Icotinib and Celecoxib groups as well as the control group,and both single agent groups had a higher apoptotic rate than the control group,with statistically significant differences(P < 0.05).3.Celecoxib combined with Icotinib down regulated the protein expression of PCNA,Bcl-2,COX-2and EGFR in xenograft tumor cells of A549 cells in nude mice,and there was a correlation between PCNA,Bcl-2,COX-2 and EGFR.(1)The positive expression of PCNA in the combination group(0.164 ± 0.065)was lower than that in the Celecoxib(0.877 ± 0.740),Icotinib(0.783 ± 0.247)and control groups(1.284 ± 0.864);the positive expression of Bcl-2 in the combination group(0.284 ± 0.119)was lower than that in the Celecoxib(0.758 ± 0.356),Icotinib(0.945 ± 0.250)and control groups(1.422 ± 0.794);the positive expression of COX-2 in the combination group The expression of EGFR in the combination group(0.620 ± 0.332)was lower than that in the Celecoxib(0.942 ±0.312),Icotinib(0.953 ± 0.325)and control groups(1.477 ± 0.323),and the positive expression of EGFR in the combination group(0.292 ± 0.172)was lower than that in the Celecoxib(1.438 ± 0.654),Icotinib(1.173 ± 0.547)and control groups(1.923 ±0.893).The differences were all statistically significant(P < 0.05).(2)The R values of the correlation coefficients between COX-2 and PCNA and Bcl-2 were 0.441,0.385,those between EGFR and PCNA and Bcl-2 were 0.344,0.494,and those between COX-2 and EGFR were 0.429,respectively.The correlations were all statistically significant(P <0.05).Conclusions 1.The selective COX-2 Inhibitor Celecoxib combined with the EGFR-TKI Icotinib exhibited synergistic growth inhibition,proliferation as well as apoptosis promotion effects on NSCLC.2.The mechanism of NSCLC growth,proliferation and apoptosis inhibition by the selective COX-2 Inhibitor Celecoxib in combination with the EGFR-TKI Icotinib may be related to the down-regulation of PCNA,Bcl-2,COX-2 and EGFR.3.The selective COX-2 Inhibitor Celecoxib combined with the EGFR-TKI Icotinib may provide a new idea for the treatment of NSCLC patients.