title: Osteopontin: a rapid and sensitive response to dioxin exposure in the osteoblastic cell line UMR-106.
abstract: 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is an endocrine disrupting environmental pollutant that, among other effects, affects bone tissue. TCDD modulates the transcription of various genes, e.g., CYP1A1, and the present study is a part of a project aiming at developing an in vitro model system for identifying biomarkers specific for dioxin-induced effects in osteoblasts. Osteopontin (OPN) is an adhesion protein, suggested to be important in bone remodeling and our results indicate that TCDD down-regulates the transcription of OPN in the osteoblastic cell line, UMR-106. The present study shows that UMR-106 expresses the AhR and that the expression of CYP1A1 is induced after exposure to TCDD, while down-regulation of OPN is an even more rapid response and a sensitive biomarker to TCDD exposure in this osteoblastic cell line. In conclusion, this osteoblastic cell line may be used as an in vitro model-system for studying dioxin-induced effects on osteoblasts.
authors.affiliation: Division of Biochemical Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden. Carolina.Wejheden@ki.se
authors.forename: Carolina
authors.initials: C
authors.lastname: Wejheden
authors.forename: Sara
authors.initials: S
authors.lastname: Brunnberg
authors.forename: Annika
authors.initials: A
authors.lastname: Hanberg
authors.forename: P Monica
authors.initials: PM
authors.lastname: Lind
mesh_terms: D000818:Animals; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism*; D004147:Dioxins / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure / Q000009:adverse effects*; D007700:Kinetics; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology*; D053495:Osteopontin; D051381:Rats; D017207:Rats, Sprague-Dawley; D012795:Sialoglycoproteins / Q000378:metabolism*
chemical_list: D004147:Dioxins; D012795:Sialoglycoproteins; C506897:Spp1 protein, rat; D053495:Osteopontin; D019363:Cytochrome P-450 CYP1A1