Interleukin-13 Promoter Genotypes and Taiwanese Breast Cancer Susceptibility

Abstract

Background/Aim: The current study aimed at evaluating the contribution of IL-13 promoter rs1881457 and rs1800925 genotypes to the risk of breast cancer in Taiwan. Materials and Methods: A total of 1,232 breast cancer cases and 1,232 age-matched controls were genotyped by typical polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology. Results: As for IL-13 rs1881457, the rates of AA, AC and CC genotypes were 54.8, 37.9 and 7.3% among the cases, and 53.8, 38.7 and 7.5% among the healthy controls, respectively; there were no statistically significant differences between the two groups (p for trend=0.8889). Also, regarding IL-13 rs1800925, there were no statistically significant differences between the two groups either (p for trend=0.6803). Furthermore, the allelic frequencies for IL-13 rs1881457 and rs1800925 were not differentially distributed between the case and control groups (p=0.6515 and 0.8753, respectively). Conclusion: The rs1881457 and rs1800925 IL-13 promoter polymorphisms may not serve as breast cancer susceptibility determinants for Taiwanese.Breast cancer is the leading female malignant disease worldwide. In both genders combined in 2018, lung cancer was the most commonly diagnosed cancer (11.6% of the total cancer cases) and the leading cause of cancer-related death (18.4% of the total cancer deaths) followed by female breast cancer (11.6%) (1). Epidemiological studies indicate that breast cancer is caused by several environmental factors, including imbalanced diet, excessive alcohol drinking and cigarette smoking, and insufficient physical exercise (2, 3). In addition, genetic factors are also involved in breast cancer susceptibility, progression and prognosis (4-7).The gene of the immune-regulatory cytokine interleukin-13 (IL-13), cloned in 1993, is located on chromosome 5q31 and has a length of approximately 1.4 kb (8). The 13 kDa protein IL-13 is secreted predominantly by Th2 lymphocytes and natural killer T cells (9, 10). The role of IL-13 in tumor progression is complex, and it seems to function like a double-sided blade. Regarding tumor promotion, it has been previously reported that the decrease in IL-13 levels in CD1deficient mice lacking natural killer T cells may inhibit tumor recurrence (11-15). In addition, there is evidence that IL-13 may directly block apoptosis and promote proliferation of tumor cells in B chronic lymphocytic leukemia and Hodgkin disease (16)(17)(18)(19). Furthermore, a study has also indicated that CD4-positive T cell-derived IL-13 can 6743 *These Authors contributed equally to this study.

Contribution of Interleukin-12A Genotypes to Breast Cancer Risk

“…The same number of healthy controls was recruited from the Health Examination Cohort. The detail procedure has been published previously (30,31). All participants contributed their peripheral blood samples for the genotyping after providing informed consent.…”