title: Aberrant p53 expression in feline vaccine-associated sarcomas and correlation with prognosis.
abstract: Eighty spontaneously occurring feline vaccine-associated sarcomas (VAS) were evaluated to determine the immunohistochemical expression of the tumor suppressor gene p53. Sixty-five of 80 VAS (81%) exhibited positive immunoreactivity with Mab240, a murine monoclonal antibody that specifically recognizes mutated p53. Only 44 of 81 tumors (55%) were positive with rabbit polyclonal antibody CM-1. CM-1 often yielded nonspecific staining of nonneoplastic tissues. Nonspecific staining was greatly reduced or absent with Mab240. Cytoplasmic staining for p53 was a consistent pattern of VAS, occurring in 44% of tumors evaluated. Cats with tumors that exhibited cytoplasmic p53 had significantly shorter time to tumor recurrence compared to those cats with tumors that exhibited nuclear p53 staining (P = 0.0284), but no significant difference in survival outcome was observed. Immunohistochemical detection of p53 offers a prognostic tool for VAS, and, because abnormal p53 expression appears to be a common feature of feline VAS, molecular targeting of mutant p53, may offer a promising new therapeutic opportunity for this cancer.
authors.affiliation: Department of Medical Sciences, Oregon Cancer Center for Animals, College of Veterinary Medicine, Oregon State University, Magruder Hall, Corvallis, OR 97331, USA.
authors.forename: A E
authors.initials: AE
authors.lastname: Hershey
authors.forename: R R
authors.initials: RR
authors.lastname: Dubielzig
authors.forename: M L
authors.initials: ML
authors.lastname: Padilla
authors.forename: S C
authors.initials: SC
authors.lastname: Helfand
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000209:etiology* / Q000378:metabolism*; D002415:Cats; D007150:Immunohistochemistry / Q000662:veterinary; D012509:Sarcoma / Q000209:etiology / Q000378:metabolism / Q000662:veterinary*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D014611:Vaccination / Q000009:adverse effects / Q000662:veterinary
chemical_list: D016159:Tumor Suppressor Protein p53