Abstract: BACKGROUND AND AIM: To study the role of ERK1/2 MAPK signaling transduction pathway in the inhibition of MCF-7 breast cancer cells by Aspisol. MATERIALS AND METHODS: The expression of COX-2 in MCF-7 breast cancer cells was detected by immunohistochemistry.The inhibitive effects of Aspisol on MCF-7 cells were assessed with MTT assay. Apoptosis was evaluated by flow cytometry. The ERK1/2,p-ERK1/2, Bcl-2 and Bax protein expressions were measured by using Western blot method. RESULTS: The expression of COX-2 in MCF-7 cells was not found.Aspisol inhibited the proliferation of MCF-7 cells in a time- and dose-dependent manner. Aspisol also induced the apoptosis of MCF-7 cells.The protein expression of p- ERK1/2、Bcl-2 decreased and Bax increased with the dose of Aspisol but not affect total ERK1/2 expression. CONCLUSION: Aspisol could affect the ERK1/2 MAPK signaling transduction pathway and induce the expressions of apoptosis-related proteins to inhibit the proliferation of MCF-7 breast cancer cells.

Key words: Aspisol, ERK1/2, apoptosis, signaling transduction, breast cancer cells