Risk-Association of Two SNPs in TOX3/LOC643714 ( RS3803662 and RS12443621 ) With Breast Cancer in IRAN

Breast cancer is recognized as one of the most common malignancies in women worldwide. The TOX3 gene was one of the first breast cancer regions to be identified through studies in populations of European and East Asian origin. Evidence on the role of TOX3 as a breast cancer susceptibility gene has been contradictory. It is a gene located at chromosome 16q12, of uncertain function, and a newly described risk factor for breast cancer. TOX3 contains a putative high-mobility group box motif, suggesting its potential to play the role of transcription factor. It has been implicated in breast cancer metastasis of the bone.Easton et al. observed that SNPs rs3803662 and rs12443621, yielded convincing evidence of association with increased risk of breast cancer.SNP rs3803662 lies 8 kb upstream of TOX3, and SNP rs12443621 is located in an linkage disequilibrium (LD ) block containing the 59 end of TOX3. TOX3 rs3803662 was observed to be associated with an increased risk of breast cancer in both BRCA1 and BRCA2-mutation carriers. SNP rs12443621 was identified to increase breast cancer risk by Easton et al. and was in strong LD with SNP rs3803662 in the TOX3 gene.Studies showed that rs3803662C/T in TOX3 on 16q12 was associated with increased estrogen receptor (ER) positive breast cancer risk, especially in ER positive breast cancer.In this breast cancer case–control study of Persian women, we investigate the associations of two candidate SNPs of TOX3 (rs3803662C/T and rs12443621A/G), and risk of sporadic breast cancer in IRAN.We will genotype two polymorphisms (rs3803662C/T and rs12443621A/G ) of the TOX3 gene using TETRA PRIMER ARMS-PCR to determine whether previously identified breast cancer susceptibility alleles are associated with sporadic breast cancer in the Iranian population.

Keywords:

Breast cancer , TOX3 , 16q12 , SNP