Abstract: AIM: To observe the effect of IFN-γ on the A549 cell proliferation and the expression of P21 protein. METHODS: A549 cells were cultured and incubated with IFN-γ.MTT colorimetric method was used to observe the effect of IFN-γ on the A549 cell proliferation, and the change of P21 protein expression was observed by the immunocytochemistry.RESULTS: Compared with those of control group, the results of MTT showed that IFN-γ could reduce the A549 cell proliferation.From the experiment of immunocytochemistry, the expression of P21 protein increased significantly after treatment with IFN-γ.CONCLUSION: IFN-γ can induce the expression of P21 protein and inhibit the A549 cell proliferation and maybe provide the new idea for the therapy of lung cancer.

Key words: IFN-γ, A549 cells, apoptosis, lung cancer, immunotherapy