The Study Of Reversal Effects And Mechanism Of CIK Cells Combined With DDP Against Drug-resistant Lung Adenocarcinoma Cell Line A549/DDP

Objective:To study the inhibitory effects of cytokine induced-killer (CIK) cells combined with Cisplatin (DDP) on the expansion of lung adenocarcinoma cell line A549/DDP in vitro. To investigate the CIK cells to reverse A549/DDP cells and reverse the incidence of drug resistance mechanisms.Methods:Peripheral blood mononuclear cells (PBMC) from healthy donors were incubated in vitro to induce CIK cells in the presence of interferon-gamma (IFN-y),IL-2 and anti-CD3 monoclonal antibody.MTT assay was employed to evaluate the cytotoxic activity of DDP,CIK cells and their combination against A549/DDP cells in vitro. Cell apoptosis among DDP group, CIK cells group and CIK cells combined with DDP group affected on A549/DDP respectively could be measure by using flow cytometry. The expression of the drug resistant gene of mRNA could be detected by DDP group, CIK cells with DDP group and CIK cells group affecting on A549/DDP cell by using RT-PCR method.And it could establish A549 cell control group,A549/DDP cell control group.And the expression drug resistant gene of mRNA in the control group could be detected.Detection of drug resistance genes include:mutidrug resistance gene 1,(MDR1), topoisomeraseâ…¡(TOPO-â…¡)and lung resistance protein(LRP).Results:MTT assay showed that CIK cells possessed a higher anti-tumor cytotoxic activity in A549/DDP cells in vitro than that in wild A549 cells.The killing activity of CIK cells combined with below IC50 doses of chemotherapy drugs to MDR tumor cells was significantly higher than that of only using of equally dose of chemotherapy drugs or the same E:T ratio of CIK cells.Increasing the E: T ratio directly correlated with higher mean percent specific lysis.The CIK cells combined with DDP evidently elevated the apoptosis, compared with using of equally dose of DDP only, and the survival rate of A549/DDP cells decreased.PCR test results showed that:The MDR1, TOPO-â…¡gene mRNA expression of A549/DDP cells were higher than of A549 cells, the MDR1, TOPO-II gene mRNA expression of CIK cells combined with DDP has decreased obviously. (P<0.05), significantly. LRP expression exist in cells of every group, and was higher in A549/DDP cells than that in A549 cells. The LRP expression of A549/DDP cells slightly decreased in the CIK cells combined with DDP group, P>0.05.Conclusions:The CIK cells can strongly increase the proliferation inhibitory effect and apoptotic effect of DDP to the drug resistant human lung adenocarcinoma line A549/DDP and CIK cells can partially reverse the MDR of A549/DDP.CIK cells may reverse drug-resistance of A549/DDP cells to DDP through down-regulating MDR1 and TOPO-â…¡.