Effects Of Photodynamic Therapy Combined With Cisplatin On The Proliferation Inhibition And Chemotherapy Sensitization Of Human Lung Adenocarcinoma A549 Cells

Objective:To investigate the proliferation inhibitory effect of hematoporphyrin derivative-photodynamic therapy(HPD-PDT)combined with cisplatin(DDP)on human lung adenocarcinoma A549 cell and the sensitizing effect of HPD-PDT on DDP chemotherapy.Methods:The A549 cells were subcultured in vitro,and when they grew to about 80%confluence,they were divided into HPD-PDT group,DDP group,combined group(DDP first and then HPD-PDT group,first HPD-PDT and then DDP group)and control group.Follow-up experiments were carried out after 24-48 hours of treatment.The proliferation inhibition rate of cells was detected by CCK-8 method,and the apoptosis of cells was detected by Hoechst33342 staining and flow cytometry(annexin V-FITC/PI double staining method),the expressions of apoptotic proteins Caspase-9,Bax,cleaved-PARP and Bcl-2 were tested using western blot.The expression levels of Caspase-9,Bax,PARP and Bcl-2 m RNA were detected by reverse transcription PCR.Results:All drug groups had inhibitory effect on the proliferation of A549 cells,especially the combined group of first HPD-PDT and then DDP group.The results of CCK8 showed that the survival rate of A549 cells in the control group,DDP group,HPD-PDT group,DDP first and then HPD-PDT group,and HPD-PDT followed by DDP group were 100%,(88.56 ± 3.57)%,(84.61 ± 3.18)%,(74.34 ± 3.54)%,(65.25 ± 3.14)% respectively.All drug groups inhibited the proliferation of A549 cell line,especially the cell survival rate in the HPD-PDT first and then DDP group was the lowest.The comparison between the groups(except the HPD-PDT group and the DDP group)was statistically significant(P<0.05).Hoechst33342 staining showed that HPD-PDT group,DDP group,DDP first and then HPD-PDT group,and HPD-PDT first and then DDP group had obvious apoptotic cells.The results of flow cytometry showed that the cell apoptosis rates of the control group,DDP group,HPD-PDT group,DDP first and then HPD-PDT group,and HPD-PDT first and then DDP group were(6.38 ± 0.36)%、(13.68 ± 0.67)%、(15.72 ±0.56)%、(22.94 ± 0.55)%、(27.42 ± 1.89)% respectively.The apoptosis rate between each medication group with the control group or the combination medication group with the single medication group was increased,and the difference(except HPD-PDT group and DDP group)were statistically significant(P<0.05),and the number of apoptotic cells in the DDP group after HPD-PDT was the largest;Western Blot results showed that the DDP group,HPD-PDTgroup and combination groups(DDP first and then HPD-PDT group,and HPD-PDT first and then DDP group)had higher protein levels of Bax and cleaved-PARP than the control group.The expressions of Bcl-2 and Caspase-9 protein were low(P<0.05);The comparison between groups(except HPD-PDT group and DDP group)was statistically significant(P<0.05).RT-PCR showed that HPD-PDT and DDP can up-regulate the expression of Bax,PARP m RNA and down-regulate the level of caspase-9 and Bcl-2 m RNA after acting on cells.The comparison between groups(except HPD-PDT group and DDP group)was statistically significant(P<0.05).Conclusion:Hematoporphyrin derivative-mediated photodynamic therapy might enhance the sensitivity of A549 cells to cisplatin chemotherapy,and the killing effect of photodynamic therapy first and then chemotherapy on lung adenocarcinoma A549 cells is the most obvious.