Anti-lung Cancer Effect And Mechanisms Of Combination Of HCPT And Crizotinib

In the past 50 years,it has been reported that the incidence and mortality of lung cancer have increased significantly and rapidly,which poses the greatest threat to human health.Following the progress of lung cancer treatment,molecular targeted drug therapy has become a hot spot,and more and more targeted drugs have been approved by FDA for the treatment of advanced lung cancer patients.However,the emergence of drug resistance greatly limits its application.Drug combination can overcome drug resistance and become the trend of cancer treatment.In our study,we have studied the effect and mechanism of 10-hydroxycamptothecin(HCPT)combined with target drug Crizotinib on lung cancer cells.HCPT is an indole alkaloid extracted from Camptotheca acuminata.It has the strongest anti-tumor effect in the same kind of anti-tumor monomers.As an inhibitor of topoisomerase I,HCPT can block cell cycle and initiate apoptosis on cancer cells.Crizotinib is an oral multi-target inhibitor of ALK,c-MET and ROS1.It is mainly used to treat advanced NSCLC patients with anaplastic lymphoma kinase(ALK)positive.Cell viability test,DAPI staining,colony formation test,Annexin V/PI double staining,reactive oxygen species(ROS)detection,mitochondrial membrane potential staining and Western blotting were used to evaluate the effects of HCPT combined with Crizotinib on lung cancer,including H460,H1975 and HCC827 cells.MTT results showed that HCPT combined with Crizotinib could significantly enhance the proliferation inhibition of H460,H1975 and HCC827 cells,and had less toxic and side effects on normal cells,which could also be demonstrated by DAPI staining and cell colony formation test.Annexin V/PI double staining showed that HCPT combined with Crizotinib enhanced the apoptosis of lung cancer cells.The combined enhancement of apoptotic induction leads to the decrease of mitochondrial membrane potential and the mitochondrial apoptotic pathway by increasing the production of ROS.The results showed that HCPT combined with Crizotinib could promote the release of Cytochrome C and down-regulate the effects of Bcl-2 and Bcl-XL in lung cancer cells,thus mediating mitochondrial pathway and inducing apoptosis.HCPT combined with Crizotinib could significantly down-regulate the expression of p-Akt,p-JNK and p-ERK,and down-regulate the expression of p-EGFR,p-AKT,p-JNK and p-ERK in H1975 cells with EGFR mutation,the expression of pEGFR,p-AKT,p-ERK and p-P38 were significantly down-regulated in HCFR mutant HC827 cells.In summary,the combined effects of HCPT and Crizotinib on lung cancer cells resulted in apoptosis through multiple pathways.From the data,we conclude that HCPT combined with Crizotinib can play a positive regulatory role in inhibiting the growth of cancer cells through multiple signal transduction pathways,and the effect is better than that of single drug.Because this combination therapy may have potential therapeutic effects on lung cancer,we need further pre-clinical investigation.