Overexpression of p53 tumor suppressor protein in spontaneously arising neoplasms of dogs.
OBJECTIVE
To determine prevalence of p53 tumor suppressor protein overexpression in spontaneously arising tumors of dogs, using the CM-1 polyclonal antibody and immunohistochemical methods. DESIGN AND SAMPLE POPULATION: Retrospective analysis was performed on archived, paraffin-embedded tumor tissue from dogs. A total of 226 tumors were evaluated, including tumors of epithelial, mesenchymal, and round cell origins.


METHODS
Overexpression of p53 was detected by indirect immunohistochemical methods, using the CM-1 rabbit anti-human p53 polyclonal primary antibody. Protein overexpression was determined by use of a grading system based on percentage of stained tumor nuclei.


RESULTS
Nuclear overexpression of p53 was detected in most squamous cell carcinomas, nasal adenocarcinomas, and perianal gland adenocarcinomas. Hemangiopericytomas, transitional cell carcinomas, mammary adenocarcinomas, apocrine gland adenocarcinomas, intestinal adenocarcinomas, mast cell tumors, and cutaneous histiocytomas had low numbers of nuclei overexpressing p53. Remaining tumor types had intermediate p53 nuclear overexpression. Cytoplasmic staining was observed in some carcinomas, particularly intestinal adenocarcinomas.


CONCLUSIONS
Overexpression of p53 is common in spontaneously arising neoplasms of dogs.


CONCLUSIONS
Prospective determination of p53 status in some tumor types may be as clinically useful in determining prognosis and predicting survival times for dogs with cancer as it is for human beings with cancer.
Gamblin
R M
RM
Department of Veterinary Clinical Sciences, Ohio State University, Columbus 43210, USA.
Sagartz
J E
JE
Couto
C G
CG
D000818:Animals; D000906:Antibodies; D002277:Carcinoma / Q000473:pathology / Q000662:veterinary; D004283:Dog Diseases; D004285:Dogs; D018219:Histiocytoma, Benign Fibrous / Q000473:pathology / Q000662:veterinary; D007150:Immunohistochemistry; D008223:Lymphoma / Q000473:pathology / Q000662:veterinary; D012515:Mast-Cell Sarcoma / Q000473:pathology / Q000662:veterinary; D009369:Neoplasms / Q000473:pathology / Q000662:veterinary*; D011817:Rabbits; D012189:Retrospective Studies; D012509:Sarcoma / Q000473:pathology / Q000662:veterinary; D016159:Tumor Suppressor Protein p53 / Q000032:analysis / Q000096:biosynthesis*
D000906:Antibodies; D016159:Tumor Suppressor Protein p53