title: Quercetin inhibits heat shock protein induction but not heat shock factor DNA-binding in human breast carcinoma cells.
abstract: The flavonoid quercetin inhibits the heat-induced synthesis of heat shock proteins (hsps) in a variety of cell lines. To determine whether quercetin could inhibit hsp expression in breast cancer cells, we used the human breast cancer cell line, MDA-MB-231. Treatment of these cells with quercetin decreased the heat-induced synthesis of hsp27 and hsp70. However, inhibition of hsp expression did not correspond with the reduced ability of heat shock transcription factors (HSFs) to bind DNA. Furthermore, while quercetin treatment inhibited HSF2 expression, it only slightly affected HSF1 expression in breast cancer cells. In contrast, quercetin inhibited both HSF DNA-binding activity and HSF expression in HeLa cells. Our studies suggest that quercetin's action is cell-type specific, and in breast cancer cells may involve regulation of HSF transcriptional activity, rather than regulation of its DNA-binding activity.
authors.affiliation: Department of Medicine/Division of Oncology, University of Texas Health Science Center, San Antonio 78284-7884, USA.
authors.forename: R K
authors.initials: RK
authors.lastname: Hansen
authors.forename: S
authors.initials: S
authors.lastname: Oesterreich
authors.forename: P
authors.initials: P
authors.lastname: Lemieux
authors.forename: K D
authors.initials: KD
authors.lastname: Sarge
authors.forename: S A
authors.initials: SA
authors.lastname: Fuqua
mesh_terms: D001665:Binding Sites / Q000235:genetics; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism*; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis / Q000187:drug effects; D006367:HeLa Cells; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D011794:Quercetin / Q000494:pharmacology*; D014157:Transcription Factors / Q000096:biosynthesis; D014407:Tumor Cells, Cultured
chemical_list: D004268:DNA-Binding Proteins; C000619706:HSF1 protein, human; D018840:HSP70 Heat-Shock Proteins; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins; D014157:Transcription Factors; C070389:HSF2 protein, human; D011794:Quercetin