title: 2,3,7,8-Tetrachlorodibenzo-p-dioxin inhibits differentiation of normal diploid rat osteoblasts in vitro.
abstract: The influence of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a potent halogenated aromatic hydrocarbon, on the development of bone tissue-like organization in primary cultures of normal diploid calvarial-derived rat osteoblasts was examined. Initially, when placed in culture, these cells actively proliferate while expressing genes associated with biosynthesis of the bone extracellular matrix. Then, post-proliferatively, genes are expressed that render the osteoblast competent for extracellular matrix mineralization and maintenance of structural as well as functional properties of the mature bone-cell phenotype. Our results indicate that, in the presence of TCDD, proliferation of osteoblasts was not inhibited but post-confluent formation of multicellular nodules that develop bone tissue-like organization was dramatically suppressed. Consistent with TCDD-mediated abrogation of bone nodule formation, expression of alkaline phosphatase and osteocalcin was not upregulated post-proliferatively. These findings are discussed within the context of TCDD effects on estrogens and vitamin D-responsive developmental gene expression during osteoblast differentiation and, from a broader biological perspective, on steroid hormone control of differentiation.
authors.affiliation: Wadsworth Center for Laboratories and Research, New York State Department of Health, Albany 12201-0509.
authors.forename: J F
authors.initials: JF
authors.lastname: Gierthy
authors.forename: J B
authors.initials: JB
authors.lastname: Silkworth
authors.forename: M
authors.initials: M
authors.lastname: Tassinari
authors.forename: G S
authors.initials: GS
authors.lastname: Stein
authors.forename: J B
authors.initials: JB
authors.lastname: Lian
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000737:chemistry; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D004171:Diploidy; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects*; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology*; D051381:Rats; D012016:Reference Values
chemical_list: D015415:Biomarkers; D000072317:Polychlorinated Dibenzodioxins