The 15-kDa selenoprotein (Sep15) is a selenocysteine-containing oxidoreductase in the endoplasmic reticulum that participates in disulfide-bond formation and protein folding control. The 3'-untranslated region (3'-UTR) contains two exclusively linked, polymorphic sites at positions 811 (C/T) and 1125 (G/A), which result in two functional haplotypes: 811C/1125G or 811T/1125A. The 811T/1125A variant occurs significantly more often in African-Americans as compared to Caucasians and has been linked to increased breast cancer risk in black women. We studied the 811C/T (rs5845) Sep15 gene polymorphism in 182 Caucasian women-83 breast cancer cases and 99 healthy controls-by pyrosequencing and polymerase chain reaction. Associations between allelic variants and clinico-pathological variables (e.g., age, stage of disease, tumor type, grading, and receptor status) were investigated. The genotype distribution in breast cancer patients (CC 63.9 %, CT 33.7 %, TT 2.4 %) and controls (69.7 %, CT 28.3 %, TT 2 %) showed no significant difference (OR 0.77, 95 % CI 0.41-1.42, p = 0.4). The overall low prevalence of the T allele was in accordance with that reported for Caucasians in previous studies. There was no significant association between 811C/T Sep15 polymorphism and any of clinico-pathological parameters. In conclusion, we are the first to report on 811C/T SEP 15 polymorphism in white breast cancer patients. Genotype variation within the 3'-UTR of the SEP 15 gene showed no association with breast cancer risk or clinico-pathological parameters in Caucasian women.
Keywords: Breast cancer; Polymorphism; Selenoprotein 15; Selenoproteins; Sep15.