Experimental study on reversal of drug-resistance of human breast cancer cell line MCF-7 by Hua-ier fungi extract in vitro

Abstract

Objective To investigate the effect and primary mechanism of Huaier fungi extract on reversal of tamoxifen-resistance of human breast cancer cell line MCF-7 in vitro. Methods Tamoxifen resistant cell line MCF-7/R cells were treated with the combination of Huaier fungi extract and Tamoxifen or separately, then the cell proliferation inhibition rates were determined by methyl thiazol tetrazolium (MTT)assay. The ratios of cells apoptosis and the change of cell cycle were also observed by flow cytometry. Protein expression of Phospho-P44/42MAPK(ERK1/2) and P44/42MAPK(ERK1/2) in each group were detected using Western blotting. Results It was demonstrated by MTT assay that the growth of MCF-7/R cells was inhibited in the combined group ( % ) (45.99 ± 6. 06) and single groups (40. 20 ± 5.54) % compared with control group (P ＜ 0. 05 ). It was revealed by flow cytometry that the MCF-7/R cell apoptosis rate were higher in the combined group (20. 03% ) and single groups ( 11.06% ) compared with control group (2. 15% ), and the combined group was the highest. Western blotting revealed that protein levels of Phospho-P44/42MAPK(ERK1/2) in combined group (0. 3153 ± 0. 0179) and single group (0. 5362 ±0. 0030) were inhibited significantly compared with control group (0. 9752 ± 0. 0034) at the 12-hour time point, and the difference is of significance in statistics science (P ＜ 0.05 ). Moreover, the difference between combined group and single group is of significance in statistics science ( P ＜ 0. 05 ). Conclusion Huaier fungi extract could reverse the tamoxifen-resistance of human breast cancer cell line MCF-7/R in vitro, and the reversal mechanism may related to the down-regulation of Phospho-P44/42 MAPK ( ERK1/2 )in MAPK pathway. It implied that Huaier fungi extract could be a significant reversal agent for clinic. Key words: Drug-resistant reversal; Tamoxifen; Huaier fungi extract