Immunohistochemical Evaluation of P16 in Canine Mammary Carcinomas

• Grant number: 25/15654-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2025
• End date: September 30, 2026
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Pathology
• Principal Investigator: Ricardo de Francisco Strefezzi
• Grantee: Bianca Godoy Bossi
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil

Abstract

Canine mammary tumors (CMTs) represent the most common neoplasms in female dogs, characterized by considerable histological heterogeneity, varying degrees of malignancy, and prognostic potential. They are composed by a tumor microenvironment (TME) that plays a critical role in tumor development, progression, and invasion. Among the cellular components of the TME, senescent cells stand out due to their Senescence-Associated Secretory Phenotype (SASP), which can exert dual effects, either suppressing neoplastic growth or promoting tumor proliferation, immune evasion, and metastasis. It is believed that these cells may remodel the microenvironment, creating favorable conditions for tumor progression. This research project aims to investigate the occurrence of cellular senescence in canine mammary carcinomas by analyzing the expression of P16, a well-established senescence-associated marker. P16 expression will be evaluated using immunohistochemistry to assess both staining intensity and the percentage of positive cells. The findings will be compared with clinical stage, histological subtype, tumor grade, and post-surgical survival, in order to determine its potential as a prognostic indicator. Our hypothesis is that P16 expression is associated with tumor aggressiveness in canine mammary carcinomas and may serve as a valuable prognostic biomarker in veterinary oncology. (AU)