title: The aryl hydrocarbon receptor as a target for estrogen receptor-negative breast cancer chemotherapy.
abstract: 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and the relatively non-toxic selective aryl hydrocarbon receptor (AhR) modulator 6-methyl-1,3,8-trichlorodibenzo-furan (MCDF) induced CYP1A1-dependent ethoxyresorufin O-deethylase activity and inhibited proliferation of seven estrogen receptor (ER) negative breast cancer cell lines. MCDF, TCDD and structurally related 2,3,7,8-tetrachlorodibenzofuran, 1,2,3,7,8-pentachlorodibenzo-p-dioxin, 2,3,4,7,8-pentachlorodibenzofuran, and 3,3',4,4',5-pentachlorobiphenyl induced CYP1A1 and inhibited proliferation of BT-474 and MDA-MB-468 cells. In BT474 and MDA-MB-468 cells transfected with a small inhibitory RNA for the AhR, the antiproliferative activity of the chlorinated aromatic compounds was reversed, whereas for MCDF, only partial reversal was observed, suggesting that this compound acts through both AhR-dependent and AhR-independent pathways in these two cell lines. MCDF also inhibited tumor growth in athymic nude mice in which MDA-MB-468 cells were injected directly into the mammary fat pad. These results suggest that the AhR is a potential drug target for treatment of ER-negative breast cancer.
authors.affiliation: Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 Holcombe Boulevard, Houston, Texas 77030, USA.
authors.forename: Shu
authors.initials: S
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Lei
authors.forename: Xinyi
authors.initials: X
authors.lastname: Liu
authors.forename: Xiangrong
authors.initials: X
authors.lastname: Li
authors.forename: Kelcey
authors.initials: K
authors.lastname: Walker
authors.forename: Leela
authors.initials: L
authors.lastname: Kotha
authors.forename: Craig
authors.initials: C
authors.lastname: Rowlands
authors.forename: Stephen
authors.initials: S
authors.lastname: Safe
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001572:Benzofurans / Q000494:pharmacology; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D016503:Drug Delivery Systems / Q000379:methods; D005260:Female; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000494:pharmacology / Q000627:therapeutic use; D018336:Receptors, Aryl Hydrocarbon / Q000037:antagonists & inhibitors* / Q000502:physiology; D011960:Receptors, Estrogen / Q000235:genetics* / Q000378:metabolism; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D001572:Benzofurans; D002352:Carrier Proteins; D000072317:Polychlorinated Dibenzodioxins; D034741:RNA, Small Interfering; D018336:Receptors, Aryl Hydrocarbon; D011960:Receptors, Estrogen; C010140:estrophilin; C054923:6-methyl-1,3,8-trichlorodibenzofuran