Genistein-induced apoptosis in MCF-7 cells involves changes in Bak and Bcl-x without evidence of anti-oestrogenic effects
- 1 November 2002
- journal article
- Published by Cambridge University Press (CUP) in British Journal of Nutrition
- Vol. 88 (5), 463-469
- https://doi.org/10.1079/bjn2002693
Abstract
South-east Asian women have a lower rate of breast cancer compared with their counterparts in western countries and the difference in soyabean consumption has been claimed to be a major contributing factor. Genistein is the most studied phytochemical in the soyabean. An anti-oestrogenic effect is believed to play a crucial part in its chemopreventive mechanism. In the present study, we expressed oestrogen receptor (OR) in an OR-negative cell line, HepG2, to investigate the pro- and anti-oestrogenic effect of genistein on the OR transcriptional activity. Genistein by itself had an estimated concentration that induced 50 % of the maximum response (EC50) of 2·5 μM FOR THE BINDING TO OR-α. IN THESE EXPERIMENTS, GENISTEIN CONCENTRATION AS HIGH AS 50 μM could not reduce the oestrogen response element-driven luciferase activities initiated by oestradiol. Instead, genistein potentiated the OR transactivational activity while cell death was detected. On the other hand, an increased Bak and a reduced Bcl-x(L) was observed at 50 μm-genistein by Western analysis. The combined effect of these two proteins could be important in the apoptotic process. Since plasma genistein >50 μm has never been documented following consuming of soyabean or soyabean products, the present study does not support the notion that dietary soyabean exerts its chemopreventive effect through antagonizing OR.Keywords
This publication has 36 references indexed in Scilit:
- 17β-Estradiol Inhibits Apoptosis in MCF-7 Cells, Inducing bcl-2 Expression via Two Estrogen-Responsive Elements Present in the Coding SequenceMolecular and Cellular Biology, 2000
- Differential Ligand Activation of Estrogen Receptors ERα and ERβ at AP1 SitesScience, 1997
- Functional Interactions between the Estrogen Receptor and the Transcription Activator Sp1 Regulate the Estrogen-dependent Transcriptional Activity of the Vitellogenin A1 ioPromoterPublished by Elsevier ,1997
- Phytoestrogen concentration determines effects on DNA synthesis in human breast cancer cellsNutrition and Cancer, 1997
- Dietary Flavonoid and Cancer Prevention: Evidence and Potential MechanismCritical Reviews™ in Oncogenesis, 1997
- Identification of an Estrogen Response Element Activated by Metabolites of 17β-Estradiol and RaloxifeneScience, 1996
- Phytoestrogens Are Partial Estrogen Agonists in the Adult Male MouseEnvironmental Health Perspectives, 1995
- Migration Patterns and Breast Cancer Risk in Asian-American WomenJNCI Journal of the National Cancer Institute, 1993
- Genistein inhibition of the growth of human breast cancer cells: Independence from estrogen receptors and the multi-drug resistance geneBiochemical and Biophysical Research Communications, 1991
- Commentary on human mammary preneoplasia. The estrogen receptor-promotion hypothesisJournal of Steroid Biochemistry, 1988