BRCA1 Gene Methylation And Folate Metabolism Gene MTHFR, MS, And Breast Cancer

Objective This study investigated the mRNA expression and the promoter methylation status of BRCA1 gene in breast cancer and the effects of mRNA expression of MS and MTHFR gene on BRCA1 methylation and their association with breast cancer morbidity.Methods RT-PCR was used to detect the mRNA expressions of BRCA1 gene,MS gene and MTHFR gene and sensitive methylation-specific-PCR (MSP) was used to detect the promoter methylation status of BRCA1 gene, in 31 samples of breast cancer and tumor adjacent tissues and 9 cases of benign breast disease.Results Significant differences of the BRCA1 mRNA expression were observed among three tissues. Methylation of BRCA1 gene in breast cancer increased significantly compared with tumor adjacent tissues and benign breast disease tissues (χ2=7.631, P<0.05). The BRCA1 methylated tumors were closely correlated with histologic grades and estrogen receptor (ER) negativity (P<0.05). The mRNA expression of MS in breast cancer tissues was significantly lower than both benign breast disease tissues and tumor adjacent tissues (P<0.05). There was a correlation between methylation of BRCA1 and expression of MS in breast cancer tissues (r=0.419, P<0.05). The mRNA expression of MTHFR in breast cancer tissues was significantly lower than both benign breast disease tissues and tumor adjacent tissues (P<0.05).Conclusion Methylation of BRCA1 could contribute to the risk of breast cancer. MS gene and MTHFR gene may be able to regulate the expression of tumor-related genes by affecting the methylation status.