The Effect of Adriamycin on Cell Apoptosis and the Expression ofDephosphorylated RB Protein in MCF-7/S Cell Line

Objective To detect the changes of apoptosis rate(AR) and dephosphorylated RB protein expression in MCF-7/S cell line treated by adriamycin(ADR),and to investigate its potential mechanism.Methods MCF-7/S cells cultured in vitro were randomly divided into experimental group and control group;Cell growth inhibition rate(IR) were examined by MTT colorimetric assay;The AR were determined by flow cytometry(FCM);And the expression of dephosphorylated RB protein were detected with immunohistochemical method.Results MTT assay revealed that ADR could inhibit the proliferation of MCF-7/S cells in a dose-dependent manner,the 50% inhibition concentration(IC_(50)) value was 0.128 mg/L;The AR of MCF-7/S treated by 0.2525 μg/ml ADR was 0.1710.1840.259 respectively,which was significantly higher than that of control group(=0.045)(P0.01);The expression of dephosphorylated RB protein in 5 μg/ml ADR experimental group was 986.8207.4,and that of control group was 131.731.9(P0.01);In 5 μg/ml ADR experimental group,there was positive correlation between AR and the expression of dephosphorylated RB protein(γ=0.998,P=0.037).Conclusion ADR exhibited growth inhibition effect and induced apoptosis on MCF-7/S cell line in vitro;Apoptosis of MCF-7/S cells induced by ADR may be related with up-regulating dephosphorylated RB protein.