title: Estrogen receptor-beta messenger RNA expression in human breast tumor biopsies: relationship to steroid receptor status and regulation by progestins.
abstract: When the level of estrogen receptor (ER)-beta mRNA in tumors, determined by reverse transcription-PCR, was assessed according to either ER status or PR status alone, determined by ligand binding assays, the level of ER-beta mRNA was significantly lower in PR+ tumors compared with PR- tumors (P = 0.036), and no association with ER status was found. Subgroup analysis showed that ER-beta mRNA expression in ER+/PR+ breast tumors was significantly less than in ER+/PR- (P = 0.009), ER-/PR+ (P = 0.029), and ER-/PR- (P = 0.023) groups. Interestingly, the ER-beta mRNA expression was specifically decreased by progestin in T47D breast cancer cells. The data suggest the possibility that expression of ER-beta in human breast tumors is a marker of endocrine therapy responsiveness.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Dotzlaw
authors.forename: E
authors.initials: E
authors.lastname: Leygue
authors.forename: P H
authors.initials: PH
authors.lastname: Watson
authors.forename: L C
authors.initials: LC
authors.lastname: Murphy
mesh_terms: D001706:Biopsy; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology* / Q000648:ultrastructure; D047629:Estrogen Receptor beta; D005260:Female; D006801:Humans; D011372:Progestins / Q000502:physiology*; D020033:Protein Isoforms; D012333:RNA, Messenger / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000096:biosynthesis* / Q000378:metabolism; D011980:Receptors, Progesterone / Q000096:biosynthesis / Q000378:metabolism / Q000502:physiology*; D014407:Tumor Cells, Cultured