J Zheng1, Z Yao. 1. Department of General Surgery, Clinical College, Chongqing University of Medical Sciences, Chongqing 400016, China.
Abstract
OBJECTIVE: To study the effect of estradiol (E2) and tamoxifen (TAM) on the apoptosis regulatory genes (bax, bcl-2) and mdr-1 in MCF-7 cells. METHODS: Immunohistochemistry, in situ hybridization were used to observe the changes in bax, bcl-2 and mdr-1 genes after treatment with E2 and TAM. RESULTS: E2 had ability to increase the expression of bcl-2 and mdr-1 but TAM decrease the expression of both. Synthetic bax oligodeoxynucleotide (ODN) was used as probe to perform in situ hybridization. It was shown that bax mRNA in MCF-7 cells was down-regulated by E2 and up-regulated by TAM. Significant correlation between bcl-2 and mdr-1 was observed after TAM treatment of MCF-7 cells (P < 0.05). CONCLUSION: TAM regulates cell apoptosis and inhibits development of drug-resistance of MCF-7 breast cancer.
OBJECTIVE: To study the effect of estradiol (E2) and tamoxifen (TAM) on the apoptosis regulatory genes (bax, bcl-2) and mdr-1 in MCF-7 cells. METHODS: Immunohistochemistry, in situ hybridization were used to observe the changes in bax, bcl-2 and mdr-1 genes after treatment with E2 and TAM. RESULTS: E2 had ability to increase the expression of bcl-2 and mdr-1 but TAM decrease the expression of both. Synthetic bax oligodeoxynucleotide (ODN) was used as probe to perform in situ hybridization. It was shown that bax mRNA in MCF-7 cells was down-regulated by E2 and up-regulated by TAM. Significant correlation between bcl-2 and mdr-1 was observed after TAM treatment of MCF-7 cells (P < 0.05). CONCLUSION:TAM regulates cell apoptosis and inhibits development of drug-resistance of MCF-7 breast cancer.