Proto-oncogene HER-2 in normal, dysplastic and tumorous feline mammary glands: an immunohistochemical and chromogenic in situ hybridization study

• Published in: BMC cancer Vol. 7; no. 1; p. 179
• Main Authors: Ordás, Javier, Millán, Yolanda, Dios, Rafaela, Reymundo, Carlos, de Las Mulas, Juana Martín
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 20.09.2007; BioMed Central; BMC
• Subjects: Animals; Breast cancer; Cats; Diseases; Evaluation; Female; Fluorescent Dyes; Genetic aspects; Health aspects; Humans; Immunohistochemistry; In Situ Hybridization; Mammary Glands, Animal - chemistry; Mammary Glands, Animal - metabolism; Mammary Glands, Animal - pathology; Mammary Neoplasms, Animal - enzymology; Mammary Neoplasms, Animal - genetics; Mammary Neoplasms, Animal - pathology; Oncogenes; Receptor, ErbB-2 - analysis; Spain
• ISSN: 1471-2407; 1471-2407
• DOI: 10.1186/1471-2407-7-179

Feline mammary carcinoma has been proposed as a natural model of highly aggressive, hormone-independent human breast cancer. To further explore the utility of the model by adding new similarities between the two diseases, we have analyzed the oncogene HER-2 status at both the protein and the gene levels. Formalin-fixed, paraffin-embedded tissue samples from 30 invasive carcinomas, 7 benign lesions and two normal mammary glands were analyzed. Tumour features with prognostic value were recorded. The expression of protein HER-2 was analyzed by immunohistochemistry and the number of gene copies by means of DNA chromogenic in situ hybridization. Immunohistochemical HER-2 protein overexpression was found in 40% of feline mammary carcinomas, a percentage higher to that observed in human breast carcinoma. As in women, feline tumours with HER-2 protein overexpression had pathological features of high malignancy. However, amplification of HER-2 was detected in 16% of carcinomas with protein overexpression, a percentage much lower than that observed in their human counterpart. Feline mammary carcinoma would be a suitable natural model of that subset of human breast carcinomas with HER-2 protein overexpression without gene amplification.