Methylation Of ER? Promoter Region In 132 Breast Cancer And Peritumoral Tissues

Objective To detect methylation status of estrogen receptor P (ER p) gene in tumor and adjacent benign tissuses and evaluate the association between tumori-genesis and methylation of gene among132incidence breast cancer cases.Methods DNA samples were isolated from tumor and adjacent benign tissues of132breast cancer patients in Anyang district, China and were analyzed for me-thylation status of ER ? gene using methylight method, the Real-time method was used to detect the expression of ER? mRNA.Results1.the expression of ER ?mRNA in tumor tissue was higher than that in adjacent benign tissue(0.18vs6.92, p=0.0000), The frequencies of methylation in tumor tissue were higher than that in adjacent benign tissue as well(31.8%vs15.4%, p=0.001) and there were higher frequencies of hypermethylation in tumor tissue (20.8%vs12.5%, p=0.058),while the correlation between ER? mRNA and methylation only be found in adjacent benign tissue.2. The methylation ratio had a positive correlation with menstrual cycle(r=0.279,p=0.005).3. The methylation of ER? gene had no correlation with age,menarche age, Menopause, profession, pregnancy, procreation, family history of cancer, Pathology type, lymph metasta-sis,TNM stage,ER,PR,C-erb-2,P53,Ki67, but patients tumor diameter?3cm had a higher frequency of ER? methylaiton(p=0.025), the higher frequency methylation was also found in left breast adjacent benign tissue (p=0.01)Conclusion Methylation of ER ? gene may be involved in tumorigenesis and de-velopment of breast cancer.older or longer menstrual cycle may be risk factors in tumorigenesis of breast cancer and menstrual cycle may affect tumor develop-ment by ERP methylation.