Polymorphisms in the antioxidant enzymes have a role in the development of breast cancer. Glutathione peroxidase 1 (GPx1) is one of the antioxidant enzymes that play an effective role in oxidative stress resistance. Pro198Leu (C → T) polymorphism affected GPx1 effectiveness, which might further play a vital role in cancer development. This study aimed to recognize the influence of the GPX1 (rs1050450) gene polymorphism on breast cancer progression and levels of certain biomarkers in patients by using a collection of blood samples from each subject. After extraction of genomic DNA, the SNP Rs1050450 analysis was performed by using polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP), and agarose gel electrophoresis. The results were visualized under UV light and analyzed with SPSS software (version 23). Additionally, this study revealed that the heterozygote CT (93.3%) genotype was higher than TT genotype in the control group, while the CT genotype was higher (55.7%) than CC and TT (38.6% and 5.7%) in patient’s group, respectively. The genotypes TT (OR = 0.0252, 95% CI = 0.0015-0.4305, P = 0.0110) and CT (OR = 0.0327, 95% CI = 0.0.0013-0.7995, P = 0.0360) were less likely to develop breast cancer (BC) sequentially. The frequency of the T allele demonstrated insignificant differences between breast cancer patients and control groups (OR = 0.4422, 95% CI = 0.2387-0.8193, P = 0.0095). The CT genotype caused an increase in glutathione (GSH) concentration and catalase (CAT) activity, while the CC genotype caused an increase in malondialdehyde (MDA) concentration and superoxide dismutase (SOD) activity in patients with BC. However, the CT genotype caused an increase in GSH concentration in the healthy control group. The results found that the genetic variation of GPX1 (rs1050450) was unrelated to BC. The rs1050450 SNP which involved in a reduced risk of BC increased levels of SOD, GSH, CAT, and MDA. The results suggested that it was necessary to monitor oxidative stress and the level of antioxidants for cancer patients.
Keywords: breast cancer; antioxidant polymorphism; RFLP-PCR; GPX1 (rs1050450); glutathione; malondialdehyde; catalase.
