Sequence analysis of RAS and RAF mutation hot spots in canine carcinoma

Area of Science:

• Veterinary Oncology
• Molecular Biology
• Cancer Genetics

Background:

• The BRAF V595E mutation is newly discovered in canine cancers, presenting a potential therapeutic target.
• RAS mutations' impact on BRAF inhibitor response in canine cancers is unknown.
• Investigating RAS mutations alongside BRAF V595E is crucial for understanding canine cancer treatment.

Purpose of the Study:

• To determine the mutational status of HRAS, KRAS, and NRAS genes in canine carcinomas.
• To analyze these RAS mutations in relation to the BRAF V595E mutation.
• To assess the potential for BRAF-targeted therapies in different canine cancer types.

Main Methods:

• DNA sequencing was used to identify mutations in HRAS, KRAS, and NRAS genes.
• BRAF V595E mutation status was determined in canine carcinoma samples.
• Four types of canine carcinoma were analyzed for both BRAF and RAS mutations.

Main Results:

• Novel HRAS mutations were found in 18% of oral squamous cell carcinomas.
• KRAS or NRAS mutations were identified in 17% of pulmonary carcinomas.
• RAS mutations and BRAF V595E were mutually exclusive, suggesting parallel MAPK pathway activation; RAS mutations were absent in urothelial and prostatic carcinomas.

Conclusions:

• BRAF V595E and RAS mutations are mutually exclusive in canine cancers studied.
• The absence of RAS mutations in urothelial and prostatic carcinomas supports BRAF-targeted therapy.
• This study provides a rationale for developing BRAF-targeted treatments for specific canine cancers.