Relationship between three novel SNPs of BRCA1 and canine mammary tumors.

The BRCA1 gene plays an important role in the development of human breast cancer, and recent research indicated that genetic variations of BRCA1 are also related to canine mammary tumors (CMTs). Here, using rapid amplification of cDNA ends (RACE), we cloned the 5'- and 3'-UTRs of BRCA1. By direct sequencing of the flanking sequences of the 5'- and 3'-UTRs of BRCA1, three previously unreported single-nucleotide polymorphisms (SNPs) were identified, two (-1228T >C, -1173C >T) in the putative promoter regions and one non-synonymous SNP (63449G >A) in exon 23. Compared with 16 normal samples, the sequences from 34 CMTs suggested that SNP (-1173C >T) was associated with the development of CMTs (odds ratio (OR)=2.57, 95% confidence interval (CI): 1.07-6.15).