Abstract P4-09-14: Evaluation of the relationship between antioxidant gene polymorphisms and breast cancer

Background: Myeloperoxidase (MPO) is a lysosomal enzyme found in monocytes, macrophages and primary granules of neutrophils. MPO participates in the biotransformation reaction of specific carcinogens by catalyzing the formation of hypochloric acid. The destruction of malignant and non-malignant cells is achieved via MPO enzyme. An important mechanism in oxidative stress regulation is the function of uncoupling proteins (UCP), which are among the mitochondrial membrane proteins. They control free radical formation. Theaim of thisstudywastodeterminetherelationshipbetweenpolymorphisms of myeloperoxidase (MPO), uncoupling protein 2 (UCP-2)genesanddevelopment of breastcancer. Methods: Thedistributions of genotypeandallelefrequencywascomparedamongthe groups.Thirty-seven caseswithbreastcancerandseventyhealthycontrolswereenrolled in thepresentstudy. Thestudyfocused on threefunctionalvariants; a variant in a variable number of 27 bp tandem repeatsin a variant in thepromoter region (G463A) of MPO gene and a variant in thepromoterregion(-866G/A) of UCP-2 gene. Wegenotypedthesevariantsusingthepolymerasechainreaction (PCR) and/or PCR- restrictionfragmentlengthpolymorphism (RFLP) method. Thedistribution of alleleand genotype in MPO and UCP-2 geneswerecomparedbetweencaseswithbreastcancer andhealthycontrolsusingchi-square test. Results: Significantlydecreasedbreastcancerriskswerefoundfor UCP-2 AA, and AG polymorphisms(For UCP-2 AA polymorphism OR=8.167; 95%CI:2.785-23.951; p=0.001, for UCP2 AG polymorphism OR=4.341; 95%CI:1.679-11.222; p=0.002).Significantly increasedbreastcancer risk wasfoundfor UCP-2 GG polymorphism (OR:5.0; 95%CI:2.207-11.327; p=0.001).Therewerenostatisticallysignificantdifference in any genotype of MPO whencaseswithbreastcancerandhealthycontrolswerecompared. Conclusion: In the current study, UCP-2 AA, AG and GG genotypes were found to be associated with breast cancer. In contrast, MPO GG, GA genotypes were not associated with breast cancer. Further studies are needed to determine whether these gene polymorphisms have a place in diagnosis or determining the risk of disease. Citation Format: Turkan Ozturk Topcu, Nilgun isiksacan, Zisan Asal Kilic, Sacide Pehlivan, Meral Gunaldi. Evaluation of the relationship between antioxidant gene polymorphisms and breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-09-14.