BMPR1B Polymorphisms (rs1434536 and rs1970801) are Associated With Breast Cancer Susceptibility in Northwest Chinese Han Females: A Case-Control Study

Background: Bone morphogenetic proteins receptor type 1B (BMPR1B) was a multifunctional signaling molecule and its abnormal expression associated with poorer prognosis. We aimed to explore the relationship between BMPR1B polymorphisms and breast cancer susceptibility among northwest population. Methods: A total of 450 healthy controls and 434 patients with breast cancers were recruited in this study. Two candidate polymorphisms, rs1434536 and rs1970801 were genotyping using Sequenom MassArray technique. Expression quantitative trait loci analysis in the GTEx portal was adopted to determine the correlation between the rs1434536 and rs1970801 polymorphism and level of BMPR1B expression. Results: We found that the T allele of rs1434536 was associated with an increased susceptibility of breast cancer [CT+TT vs. CC: adjusted OR (95% CI) = 1.35(1.02-1.78), P_adjusted = 0.034; CT vs. CC adjusted OR (95% CI) = 1.39(1.03-1.87), P_adjusted = 0.029]. For rs1970801, carrying minor allele T was significantly associated with an increased risk of breast cancer [GT+TT vs. GG: adjusted OR (95% CI) = 1.52(1.14-2.01), P_adjusted = 0.004; GT vs. GG adjusted OR (95% CI) = 1.56(1.15-2.09), P_adjusted = 0.004]. Stratified analyses found statistical significance existing in women under 49 years of age, BMI less than 24 kg/m², and premenopausal women for both rs1434536 and rs1970801. Expression quantitative trait loci analysis in the GTEx portal proved that the minor alleles of rs1434536 T and rs1970801 T was significantly associated with higher expression level of BMPR1B. Conclusion: BMPR1B polymorphisms (rs1434536 and rs1970801) may increase susceptibility to breast cancer in Chinese Han women.