Abstract: Objective To study the cell signal mechanism of tetrandrine-induced apoptosis of human breast cancer cell line MCF-7. Methods The effects of tetrandrine-induced apoptosis of MCF-7 (1, 5, 10 μmol·L^-1) was detected by flow cytometry. Western blot was performed to assess expression of Akt, p-Akt ser437 and p-Akt Thr308 in MCF-7. The activity of Akt was detected by Akt activity assay kit (KinaseSTAR). Results Different doses of tetrandrine (Tet) could induce apoptosis of MCF-7 in a dose-dependent manor. Tet could significantly inhibit expression of p-Akt ser437and p-Akt Thr308, but had no effect to expression of total Akt in MCF-7. Tet could down-regulate the activity of Akt of MCF-7. Conclusion Tet can induce apoptosis of MCF-7 cells through suppressing Akt activity.

Key words: tetrandrine, breast cancer, Akt