title: Induction of c-fos and c-jun protooncogenes expression by formaldehyde-releasing and epoxy resin-based root-canal sealers in human osteoblastic cells.
abstract: An important requirement for a root-canal sealer is biologic compatibility; most evaluations have focused on general toxicological and local tissue irritating properties. There is only scant information about mutagenicity or carcinogenicity testing for root-canal sealer. It has been shown that c-fos and c-jun are induced rapidly by a variety of chemical and physical stimuli. Numerous works have extensively investigated the induction mechanisms of c-fos and c-jun protooncogenes by these agents; however, little is known about the induction of cellular signaling events and specific gene expression after cell exposure to root-canal sealers. Therefore, we used osteoblastic cell line U2-OS to examine the effect of zinc-oxide eugenol-based (N2 and Endomethasome), epoxy resin-based (AH Plus), and calcium hydroxide-based (Sealapex) root-canal sealers on the expression of c-fos and c-jun protooncogenes to understand in more detail the molecular mechanisms of root-canal sealer-induced genotoxicity. The cytotoxicity decreased in an order of N2 > Endomethasome > AH Plus > Sealapex. In addition, N2, Endomethasome, and AH Plus rapidly induced c-jun and c-fos mRNA levels in cells. However, Sealapex did not induce c-jun and c-fos mRNA expression at detectable levels all time points. Taken together, persistent induction of c-jun and c-fos protooncogenes by formaldehyde-releasing and epoxy resin-based root-canal sealers may be distributed systemically via apex to cause some unexpected adverse effects on human beings. These data should be taken into consideration when choosing a root-canal sealer.
authors.affiliation: Department of Dentistry, Chung Shan Medical and Dental College Hospital, Taichung, Taiwan.
authors.forename: Fu-Mei
authors.initials: FM
authors.lastname: Huang
authors.forename: Yih-Shou
authors.initials: YS
authors.lastname: Hsieh
authors.forename: Kuo-Wei
authors.initials: KW
authors.lastname: Tai
authors.forename: Ming-Yung
authors.initials: MY
authors.lastname: Chou
authors.forename: Yu-Chao
authors.initials: YC
authors.lastname: Chang
mesh_terms: D001672:Biocompatible Materials / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D004853:Epoxy Resins; D005557:Formaldehyde; D005786:Gene Expression Regulation / Q000187:drug effects*; D016762:Genes, fos / Q000187:drug effects* / Q000235:genetics; D016758:Genes, jun / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D010006:Osteoblasts / Q000187:drug effects*; D012333:RNA, Messenger / Q000187:drug effects; D012387:Root Canal Filling Materials / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D001672:Biocompatible Materials; D004853:Epoxy Resins; D012333:RNA, Messenger; D012387:Root Canal Filling Materials; D005557:Formaldehyde