Regulation of estrogen receptor-α expression in MCF-7 cells by taxol

Results presented in this study demonstrate that treatment of MCF-7 cells with taxol resulted in induction of estrogen receptor-alpha (ERalpha) gene transcription with a subsequent increase in ERalpha mRNA; this effect was promoter specific since taxol did not affect total transcription in MCF-7 cells and lacked an effect on transcription of the human acidic ribosomal phosphoprotein protein PO, progesterone receptor, and pS2 genes. In contrast to the increase in transcription of the ERalpha gene, taxol inhibited translation of the ERalpha mRNA. This effect is also transcript specific taxol did not alter total protein synthesis and did not affect the concentration of progesterone receptor protein in the cell. The overall result of taxol treatment was to decrease the concentration of ERalpha protein in the MCF-7 cells. Evidence is presented that the effects of taxol on ERalpha gene transcription may be mediated through the induction of p53.