Abstract: The effect of tamoxifen(TAM) and interleukin-6(IL-6) on apoptosis in estrogen receptorpositive human breast cancer cell line(MCF-7) was studied. The sample cells stained by propidium iodide(PI) were detected, analyzed and fitted by FCM. The result showed that TAM and IL-6 could induce apoptosis of MCF-7 cells, the difference of apoptotic ratio between the control group and the treatment group was significant respectively. The cell apoptosis was enhanced when combining treatment with TAMand IL-6 was performed. The increase rate is much higher than that of either TAM or IL-6 alone, the differences were significant. The data indicated that the effect of TAM combined IL-6 is not an additive interraction, but possibly a synergistic interraction.

Key words: TAM, IL-6, apoptosis, FCM, preast cncer