ABSTRACT
Purpose:To study if tamoxifen (TAM) can induce growth arrest and apoptosis of ER negative MA782 mouse breast cancer cell line and to explore the molecular mechanisims. Methods:MA782 cells were cultured in RPMI 1640 medium with TAM.The proliferative activity of cells was detected by MTT methods, and cells apoptosis by flowcytometric methods. The expression of cyclin D1, CDK4 and TGF ?1 proteins was detected by immunohistochemical methods, the semi quantification of protein expression was analyzed by pathological image analysis software.Results:TAM can induce growth arrest and apoptosis of cells. ICC results showed that MA782 cells were ER negative. There was no change of cell cycle regulators in cells with 2 ?mol/L TAM. After 48、72h with 6 ?mol/L or 10 ?mol/L TAM, the level of cyclin D1 proteins decreased from 132.5?0.02 to 129.67?0.03、126.18?0.03(6 ?mol/L) and 109.1?0.01、73.56?0.02(10 ?mol/L),CDK4 proteins decreased from 107.2?0.01 to 91.23?0.02、76.21?0.03(6 ?mol/L)and 83.52?0.02、72.03?0.01(10 ?mol/L), while TGF ?1 proteins increased from 59.72?0.02 to 83.2?0.04、121.75?0.03(6 ?mol/L)and 96.83?0.02、139.01?0.05(10 ?mol/L),The difference was significant( P