Estrogen receptor alpha (ERα) promoter methylation status in tumor and serum DNA in Egyptian breast cancer patients

• Methylation status of ER3, ER4 and ER5 was 65%, 26.7% and 61.7% in tissue.
• Methylation status of ER3, ER4 and ER5 was 57.5%, 21.7% and 55.8% in serum.
• Serum DNA methylation of ERα gene can be used as a marker in breast cancer.

BackgroundStatus of DNA methylation is one of the most common molecular alterations in human neoplasia. Because it is possible to detect these epigenetic alterations in the bloodstream of patients, we investigated the aberrant DNA methylation status of estrogen receptor alpha (ERα) in patient pretherapeutic sera and tissue.Materials and methodsIn this case control study the patient series consisted of 120 sporadic primary breast cancer cases and 100 patients with benign breast lesion. ER3, ER4, and ER5 primers were used for methylation-specific polymerase chain reaction (MSP) to analyze the CpG methylation of promoter region of ERα gene. Correlation between ER3, ER4, and ER5 methylation and clinicopathological characteristics of the patients was investigated.ResultThe methylation status of ER3, ER4 and ER5 was 65%, 26.7% and 61.7% in tissue respectively and 57.5%, 21.7% and 55.8% in serum respectively. The concordance between tumor and serum DNA methylation was 80%, 72% and 92% for ER3, ER4 and ER5 respectively.ConclusionsThis study demonstrated the potential utility of serum DNA methylation of ERα gene promoter as a non-invasive diagnostic and/or prognostic marker in patients with breast cancer.