title: Immunohistochemical localization of p53, PCNA, and TGF-alpha proteins in formaldehyde-induced rat nasal squamous cell carcinomas.
abstract: Mutation of the p53 tumor suppressor gene is a common event in many human cancers and has been specifically associated with invasive squamous cell carcinoma of the human skin and respiratory tract. Alterations in the p53 gene have also been identified in certain rodent tumors, including formaldehyde-induced nasal squamous cell carcinomas. Overexpression of transforming growth factor-alpha (TGF-alpha) is associated with carcinomas of the head and neck and respiratory tract in human patients and formaldehyde-induced rat nasal squamous cell carcinomas. Sections of rat noses containing tumors and other formaldehyde-induced lesions from rats exposed to 15 ppm formaldehyde vapor were examined using immunohistochemical techniques to detect and identify potential relationships between the presence and distribution of p53, proliferating cell nuclear antigen (PCNA), and TGF-alpha proteins. The five tumors that had p53 mutations were for mutant p53 protein by immunohistochemistry and three of six tumors with no detected p53 mutations were also immunoreactive for p53 protein. The presence, pattern, and distribution of p53 staining in tissue sections depended on the morphology of the lesion. PCNA immunoreactivity was strikingly similar in pattern and distribution to p53 immunoreactivity. The pattern and distribution of immunoreactivity for TGF-alpha did not directly correlate with the other markers. Mutation of the p53 tumor suppressor gene may be an important step in the progression of formaldehyde-induced nasal carcinogenesis in the rat. This study demonstrated that immunohistochemistry is a useful tool for the identification of sites within tumors that might have p53 mutations.
authors.affiliation: Chemical Industry Institute of Toxicology (CIIT), Research Triangle Park, North Carolina 27709, USA.
authors.forename: D C
authors.initials: DC
authors.lastname: Wolf
authors.forename: E A
authors.initials: EA
authors.lastname: Gross
authors.forename: O
authors.initials: O
authors.lastname: Lyght
authors.forename: E
authors.initials: E
authors.lastname: Bermudez
authors.forename: L
authors.initials: L
authors.lastname: Recio
authors.forename: K T
authors.initials: KT
authors.lastname: Morgan
mesh_terms: D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced / Q000737:chemistry* / Q000473:pathology; D005557:Formaldehyde; D007124:Immunoenzyme Techniques; D008297:Male; D009669:Nose Neoplasms / Q000139:chemically induced / Q000737:chemistry* / Q000473:pathology; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis*; D051381:Rats; D011916:Rats, Inbred F344; D016211:Transforming Growth Factor alpha / Q000032:analysis*; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000032:analysis*
chemical_list: D018809:Proliferating Cell Nuclear Antigen; D016211:Transforming Growth Factor alpha; D016159:Tumor Suppressor Protein p53; D005557:Formaldehyde