ABSTRACT
Objective To investigate the effect of Shugan-Yishen formula on Tamoxifen-resistant MCF-7 cell line(LCC9) through HER2-ERK/MAPK-ERα pathway. Methods Four serums were prepared with the method of serum pharmacology:the serum of Shugan-Yishen formula, Shugan-Yishen formula plus Tamoxifen(TAM), blank and TAM alone. After LCC-9 cells were affected in the above-mentioed serums in vitro, the inhibition rate and the level of mRNA as well as the protein expression of HER2, ERα, ERK/MAPK, p-ERK/MAPK were detected. Results MTT showed that TAM alone group、Shugan-Yishen formula group and the Shugan-Yishen formula plus TAM group had higher inhibition rates at 48th hour, the inhibition rates was(6.61±0.129)%, (47.43±2.24)%, (54.19±3.364)%, compared to the blank group, Shugan-Yishen formula group and the Shugan-Yishen formula plus TAM group had a stronger inhibition on LCC9 at 48th hour (P0.05). RT-PCR result showed that compared to the blank group, the expression levels of ESR1 mRNA of group of Shugan Yishen formula plus TAM werehigher by and large at 48th hour (P0.05). Conclusions ①The combination of Shugan-Yishen formula with tamoxifen can inhibit the LCC9 cells. The inhibition effect reaches the peak at 48th hour. ②The mechanism of Shugan-Yishen formula plus TAM combination effects on human breast cancer TAM-resistant cell line LCC9 may improve the sensitivity of ERαby inhibiting the expression of HER2, ERK/MAPK.