The Synergistic Inhibitory Effect Of Melittin Combined With Icotinib On Different Lung Adenocarcinoma Cell Lines And Reversal Of Drug Resistance

Part one The inhibitory effect of melittin on different non-small cell lung cancer cell linesObjective: To investigate the effects of melittin on proliferation,apoptosis,migration and invasion of different non-small cell lung cancercell lines.Methods: Different concentrations(0.5,1,2,3,4,5?g/m L)of melittinwere used to intervene NSCLC cell lines A549(EGFR wild type),PC-9(EGFR-TKIs sensitive)and NCI-H1975(EGFR-TKIs resistant).The inhibition of migration and invasion of melittin was detected by scratch test and transwell method.The effect of melittin on apoptotic proteins was detected by western blot.SPSS 21.0 statistical software was used for data processing,the measurement data were presented as (?)±s,the comparisonbetween groups was statistically analyzed by one-way anova,and thecomparison between groups was conducted by LSD method in pairs.Thetest level was P=0.05,and P<0.05 was considered statistically significant.Results:Melittin showed significant proliferation inhibition on NSCLC cell lines A549,PC-9 and NCI-H1975 in a dose-dependent manner(P<0.05).Pwise comparison of IC50 values of three tumor cells by LSD showed that,compared with the EGFR-mutated NSCLC cell lines(PC-9 and NCI-H1975),the melittin had a stronger inhibitory effect on EGFR wild-type A549 cells,with a smaller IC50 value.Melittin induced apoptosis of NSCLC cells,and the apoptosis was more obvious with the increase of concentration(P<0.05).The results of scratch test showed that the migration ability of cells decreased significantly after the action of bee venom peptide(P<0.05).Transwell chamber results showed that melittin significantly inhibited the invasion ability of all cell lines,and the difference was statistically significant(P<0.05).Western blot results showed that the expression of Bax and Caspase3 proteins in the melittin treatment group showed an upward trend,while the expression of Bcl-2 proteins showed a downward trend,with statistically significant differences(P<0.05).Summary: Melittin can inhibit the proliferation and induce apoptosis of different NSCLC cell lines.Melittin inhibited the migration and invasion of different types of non-small cell lung cancer cell lines.At the same time,the induction of apoptosis may be related to the increase of Bax and Caspase3 protein expression and the decrease of Bcl-2 protein expression.Part two Study on the synergistic inhibitory effect of Melittin combined with Ictinib on different non-small cell lung cancer cell linesObjective: To observe the effect of Melittin combined with Ictinib on the biological behavior of lung adenocarcinoma cell line and the effect of Melittin to reverse the resistance of lung cancer drug-resistant cell line NCI-H1975 to Ictinib,and to explore the possible mechanism of overcoming the resistance.Methods: The proliferation inhibition of A549(EGFR wild-type),PC-9(EGFR-TKIs sensitive)and NCI-H1975(EGFR-TKIs resistant)cell lines of non-small cell lung cancer was detected by CCK-8 assay.The effects of proapoptotic activity of A549,PC-9 and NCI-H1975 in different non-small cell lung cancer cell lines were detected by flow cytometry Melittin(2?g/m L),Ictinib(1?M)and combined use.The effects of Melittin(2?g/m L),Ictinib(1?M)and its combination on the inhibition of migration and invasion of A549,PC-9 and NCI-H1975 cell lines of non-small cell lung cancer were detected by the scrape experiment and transwell method.Western blot method was used to detect the effects of Melittin(2?g/m L),Ictinib(1?M)and their combination on the expression levels of apoptosis-related proteins Bax,bcl-2 and Caspase3 in A549,PC-9 and NCI-H1975 cell lines of NSCLC.SPSS 21.0 statistical software was used for data processing.Measurement data were expressed as (?)±s.One-way anova was used for statistical analysis.LSD method was used for pairwise comparison among the groups.The test level was 0.05,and P<0.05 was considered to be statistically significant.Results: CCK-8 test results showed that compared with the single drug group and the blank control group,the cell proliferation ability of the combined drug group was significantly weakened;flow cytometry results showed that the cell apoptosis rate of the combined group was significantly increased compared with the single drug group and the blank control group.Suggesting that the combined drug group can induce cell apoptosis more than the single drug group,the results of migration experiments and Transwell invasion experiments show that compared with the single drug group and the blank control group,the cell migration and invasion ability of the combined group is significantly reduced,and the difference is statistically significant Significance(P <0.05),compared with the blank control group,Western blot results showed that the expression levels of Bax and Caspase3 in the different treatment groups increased to varying degrees,and the expression levels of Bcl-2 protein decreased in the combined group and the single drug group.By comparison,the expression levels of Bax and Caspase3 protein were significantly increased,and the expression levels of Bcl-2 were significantly decreased,and the difference was statistically significant(P <0.05).Summary: Melittin combined with Ictinib can obviously inhibit the proliferation,migration and invasion of lung cancer cell lines and promote the apoptosis of tumor cells.In addition,compared with the monotherapy group,the combined group had a more obvious inhibitory effect on NSCLC cell lines.For NCI-H1975 cells that were resistant to Ictinib,the inhibition rate of the combined group was significantly higher than that of the monotherapy group after the combination of melittin(2?g/m L)and Ictinib(1?M).The results indicated that melittin may have a sensitizing and detoxifying effect,and the combination of melittin and Ictinib can restore the sensitivity of Ictinib to drug-resistant cell lines to a certain extent.Conclusion:1.Melittin can significantly inhibit the proliferation and induce apoptosis of different types of non-small cell lung cancer cell lines,and has a stronger inhibitory effect on EGFR wild-type cell A549.Melittin can inhibit the migration and invasion of different types of non-small cell lung cancer cell lines.2.Melittin combined with Ictinib can obviously inhibit the proliferation,migration and invasion of lung cancer cell lines and promote the apoptosis of tumor cells.In addition,compared with the monotherapy group,the combined group had a more obvious inhibitory effect on NSCLCcell lines.For NCI-H1975 cells that were resistant to Ictinib,the inhibition rate of the combined group was significantly higher than that of themonotherapy group after the combination of melittin and Ictinib.The results showed that the combination of melittin and Ictinib could restore the drug sensitivity of drug-resistant cell lines to Ictinib to a certain extent.