title: Global gene expression profiles induced by phytoestrogens in human breast cancer cells.
abstract: The nutritional intake of phytoestrogens seems to reduce the risk of breast cancer or other neoplastic diseases. However, these epidemiological findings remain controversial because low doses of phytoestrogens, achievable through soy-rich diets, stimulate the proliferation of estrogen-sensitive tumor cells. The question of whether such phytochemicals prevent cancer or rather pose additional health hazards prompted us to examine global gene expression programs induced by a typical soy product. After extraction from soymilk, phytoestrogens were deconjugated and processed through reverse- and normal-phase cartridges. The resulting mixture was used to treat human target cells that represent a common model system for mammary tumorigenesis. Analysis of mRNA on high-density microarrays revealed that soy phytoestrogens induce a genomic fingerprint that is indistinguishable from the transcriptional effects of the endogenous hormone 17beta-estradiol. Highly congruent responses were also observed by comparing the physiologic estradiol with daidzein, coumestrol, enterolactone, or resveratrol, each representing distinct phytoestrogen structures. More diverging transcriptional profiles were generated when an inducible promoter was used to reconstitute the expression of estrogen receptor beta (ERbeta). Therefore, phytoestrogens appear to mitigate estrogenic signaling in the presence of both ER subtypes but, in late-stage cancer cells lacking ERbeta, these phytochemicals contribute to a tumor-promoting transcriptional signature.
authors.affiliation: Institute of Pharmacology and Toxicology, University of Zürich-Vetsuisse, Winterthurerstrasse 260, Zürich, Switzerland.
authors.forename: Ramiro
authors.initials: R
authors.lastname: Dip
authors.forename: Sarah
authors.initials: S
authors.lastname: Lenz
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Antignac
authors.forename: Bruno
authors.initials: B
authors.lastname: Le Bizec
authors.forename: Hans
authors.initials: H
authors.lastname: Gmuender
authors.forename: Hanspeter
authors.initials: H
authors.lastname: Naegeli
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D002417:Cattle; D004958:Estradiol / Q000494:pharmacology; D047629:Estrogen Receptor beta / Q000235:genetics / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D019833:Genistein / Q000494:pharmacology; D006801:Humans; D007529:Isoflavones / Q000494:pharmacology; D017705:Lignans / Q000494:pharmacology; D008892:Milk / Q000737:chemistry; D009363:Neoplasm Proteins / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D048789:Phytoestrogens / Q000494:pharmacology*; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D041942:Soy Milk / Q000737:chemistry; D014407:Tumor Cells, Cultured
chemical_list: D014408:Biomarkers, Tumor; D047629:Estrogen Receptor beta; D007529:Isoflavones; D017705:Lignans; D009363:Neoplasm Proteins; D048789:Phytoestrogens; D012333:RNA, Messenger; D004958:Estradiol; C004742:daidzein; D019833:Genistein; D015107:4-Butyrolactone; C029497:2,3-bis(3'-hydroxybenzyl)butyrolactone