BRAF-V600E Protein Expression in Canine Malignant Cutaneous Melanoma, in Accordance with the Introduction of Biomarkers in Comparative Oncology Studies

Abstract

Background: Melanoma is the cause of death of 1.3% of all cancer patients in humans. The key role of BRAF protein in the progression of human melanoma has been confirmed and its prognostic significance has been revealed. Because canine cancer resembles human cancer in biological behavior and molecular abnormalities, BRAF protein may be expressed in canine melanoma, the same as human melanoma. despite the investigation of BRAF mutation in canine melanoma, the status of BRAF at the protein level in canine skin melanoma has not yet been examined. Methods: Thirty-two formalin-fixed, paraffin-embedded tissue samples of canine malignant cutaneous melanoma were randomly selected. After cutting into 3-μm-thick sections, the samples were evaluated for BRAF protein expression by immunohistochemistry and using the anti-BRAF V600E (VE1) mouse monoclonal antibody. Results: The BRAF status was assessed using the Allred scoring system. Among the 32 samples examined, 21 samples were negative and 11 cases showed high BRAF protein expression. Conclusion: The detection of positive BRAF expression in 34.3% of canine cutaneous melanoma samples could be a step forward to improve treatment options, use the dog as an animal model in human melanoma clinical trials, and possibly identify a new prognostic biomarker in canine melanoma.

Keywords

• immunohistochemistry
• BRAF
• canine cutaneous melanoma
• protein expression