Association of DNMT1 Gene Polymorphisms in Exons With Sporadic Infiltrating Ductal Breast Carcinoma Among Chinese Han Women in the Heilongjiang Province

Background: Infiltrating ductal carcinoma (IDC) is the most common malignant breast cancer in women, and genetic factors appear to play a significant role in the susceptibility to IDC. Alteration of DNA methylation is an epigenetic change in human cancers, including breast cancer. DNA-methyltransferase 1 (DNMT1) is a major enzyme that determines genomic methylation patterns. In order to clarify the association of DNMT1 polymorphisms with IDC, a case-control study was conducted in women from the Heilongjiang Province, in the northeast of China. Patients and Methods: We scrutinized the 2 genetic polymorphisms in exons of DNMT1 that may influence the activity of DNMT1. Our research subjects consisted of 305 patients with IDC and 314 age-matched healthy controls. Genotypes were determined by polymerase chain reaction restriction fragment length polymorphism. Data were analyzed using the chi(2) test by SPSS, version 13.0, and Haploview, version 4.1. The association between DNMT1 polymorphisms and the clinical features of IDC was analyzed. Results: In rs16999593, the frequency of CT genotype and C allele were lower in patients than in controls (P = .028 and P = .017, respectively). Also, rs2228611 AG genotype was higher in patients than in controls (P = .015). The frequency of haplotype CA was lower in patients than in controls (P = .034). Significant association was shown between the 2 single nucleotide polymorphisms of the DNMT1 gene and progesterone receptor (PgR) and p53 status. No association was found between DNMT1 gene polymorphisms and tumor size or estrogen receptor status. Conclusion: Our results was a previous study, which suggested that DNMT1 gene polymorphisms in exons may provide valuable information for predicting the sporadic IDC risk and may be associated with prognosis factors such as PgR and p53 status in Chinese Han women in the Heilongjiang Province.