Analysis of DNA-dependent protein kinase (DNA-PKcs) expression in canine cutaneous mast cell tumors

• Grant number: 25/11895-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2025
• End date: August 31, 2026
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Pathology
• Principal Investigator: Ricardo de Francisco Strefezzi
• Grantee: Maria Eduarda Capiotto e Silva
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil

Abstract

Mast cell tumours (MCTs) are neoplasms with variable behaviour and high incidence in dogs, representing the most common malignant cutaneous tumour in this species. For this reason, they have been the focus of research aimed at identifying new prognostic markers and developing more effective therapies. DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is a protein involved in repairing double-strand DNA breaks through the non-homologous end joining (NHEJ) pathway. When dysregulated, it has demonstrated important roles in human tumorigenesis, such as telomere maintenance and immune signalling, thus representing a promising area for veterinary medicine. The objective of the present study is to characterize and quantify DNA-PKcs expression in canine MCTs, aiming to evaluate its potential as a prognostic indicator for the disease. Immunohistochemistry will be used to identify and characterize DNA-PKcs expression in canine MCTs. DNA-PKcs-positive and -negative mast cells, as well as staining intensity, will be quantified within an area of 2.37 mm² per sample. The results will be compared with the histological grading of the tumours, disease-related mortality, and post-surgical survival. Our hypothesis is that DNA-PKcs is highly expressed in high-grade MCTs and those with a poorer prognosis. (AU)