Effects of IFN-γ and IL-4 on the growth and the estrogen receptor subtypes of breast cancer cell MCF-7

OBJECTIVE:To study the effects of IFN-γ and IL-4 on the growth and the ER subtypes of MCF-7 cell.METHODS:MCF-7 cell was treated with different level of IFN-γ(50,100 and 150 μg/L) or IL-4(5,10 and 25 μg/L) for 24,48,72 and 96 hours.After detecting the cell proliferation by MTT test,MCF-7 was treated with 100 μg/L IFN-γ(M/IFN-γ) or 10 μg/L IL-4(M/IL-4) for 96 hours during the following tests.Western blot assay was used to detect the ER expression and the flow cytometry was applied to analyze cell cycle.RT-PCR test was used to detect the expression of apoptosis suppression gene.RESULTS:Compared with the control group,the cell proliferation was inhibited significantly after treated with IFN-γ for 96 hours(P values were 0.000 and 0.003 relatively for 100 and 150 μg/L group).The percentage of cells in G0-G1 phase was increased but in S phase was decreased(P values were 0.003 and 0.005 relatively).The protein expression of ERβ was increased(P=0.038).On the other hand,after treated with IL-4 for 96 hours,the proliferation of MCF-7 was improved significantly(P value were 0.006 and 0.002 relatively for 10 and 25 μg/L group) and the percentage of cells in S phase was increased(P=0.007),the protein expression of ERβ was decreased(P=0.021) whereas the apoptosis suppression gene expression was increased(P values were 0.002,0.000 and 0.004).CONCLUSIONS:IFN-γ and IL-4 can up-regulate or down-regulate the expression of ERβ,and then inhibit or promote tumor growth.Therefore,the effects of Th1/Th2 bias on the growth of breast cancer cell may be associated with the expression ratio of ER.