Abstract: Abstract:Objective To explore the effect of IL-24 gene on proliferation and apoptosis of human breast cancer cell line MDA-MB-231. Methods The recombinant shuttle vector pDC316-hIL-24-EGFP was transiently transfected into human breast cancer cell line MDA-MB-231 with lipofectamine. Both IL-24 mRNA and protein were detected by RT-PCR and Western blot respectively.The inhibition of cell proliferation was evaluated by MTT assay. Changes in cell cycle were detected by flow cytometry(FCM) .The cell apoptosis was studied by Hoechst 33258 staining. Results　IL-24 was proved successfully transcribed and expressed in MDA-MB-231 cells. IL-24 enhanced protein Caspase-3 expression level of MDA-MB-231cells. The IL-24 expression inhibited MDA-MB-231 cells proliferation. In MDA-MB-231cells of IL-24 over-expressed the DNA synthesis was inhibited and arrested in G2/ M phrase according to FCM.Increased apoptosis of MDA-MB-231 cells were observed by Hoechst33258 staining.Conclusion IL-24 gene overexpressed was able to effectively inhibit the proliferation and promote the apoptosis of breast cancer cells,which may be due to enhancing of protein Caspase-3 leve.

Key words: IL-24 gene, Breast cancer, Transfection, Apoptosis