Effects of estrogen on apoptotic pathways in human breast cancer cell line MCF-7.
We utilized a reverse transcription-PCR method to examine the effect of estrogen on the expression of mRNA for Bcl-2 and Bax, two modulatory proteins in the apoptotic pathway, in human breast cancer cell line MCF-7. We found that the bcl-2 mRNA levels in the cells exposed to 17 beta-estradiol were higher than those of control cells. Although the relative bax mRNA levels remained unchanged, the changes in bcl-2 mRNA level occurred in a time- and concentration-dependent fashion. In addition, pretreatment with 17 beta-estradiol protected MCF-7 cells from apoptosis. Our study provides evidence that responses of breast epithelial cells toward a steroid sex hormone involve regulation of the apoptotic pathway.
Wang
T T
TT
Laboratory of Nutritional and Molecular Regulation, National Cancer Institute-Frederick Cancer Research and Development Center, NIH, Maryland 21702-1201, USA.
Phang
J M
JM
D017209:Apoptosis / Q000187:drug effects*; D001483:Base Sequence; D001943:Breast Neoplasms; D002460:Cell Line; D017931:DNA Primers; D004958:Estradiol / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011505:Protein-Tyrosine Kinases / Q000096:biosynthesis; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D019253:Proto-Oncogene Proteins c-bcl-2; D011519:Proto-Oncogenes / Q000187:drug effects; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D013629:Tamoxifen / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D051028:bcl-2-Associated X Protein
C494826:BAX protein, human; D017931:DNA Primers; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D051028:bcl-2-Associated X Protein; D013629:Tamoxifen; D004958:Estradiol; D011505:Protein-Tyrosine Kinases