Study on mechanism of Interleukin-2 and Interleukin-12 against lung adenocarcinoma cell

Objective To detect the cytotoxicity of cisplatin(DDP) combined with Interleukin-2(IL-2) and /or Interleukin-12(IL-12) against lung adenocarcinoma A549 cell line(A549)and DDP resistant A549 cell line(A549/DDP),in order to explore the multidrug resistant mechanisms of A549/DDP.Method Cytotoxic testing in vitro was performed by MTT assay,and the expressions of mutant P53,bcl-2 and MDR-1 before and after action of cytokine were detected by immunohistochemical staining.Results The cytotoxicity of DDP alone against the two cell lines(A549 and A549/DDP) was not apparently different from that of DDP combined with IL-2,but was signficantly incereased with the IL-12 combination,and enhanced further by adding IL-2.The expression of mutant P53,Bcl-2 and MDR-1 in A549/DDP cells was higher than that in A549 cells.As compared with untreated A549 and A549/DDP cells,the expression of mutant P53,bcl-2 and MDR-1 reduced significantly in IL-12 treated cells.Conclusion The combination of IL-12 and DDP has synergic inhibition on A549 cells and IL-12 can increase the sensibility of A549/DDP on DDP maybe through changing the expression of mutant P53,bcl-2 and MDR-1,while IL-2 can enhance the above effects further.The overexpression of bcl-2 and mutant P53 in A549/DDP cells may be one of the important mechanisms for multidrug resistance.