Purpose: The nuclear hormone receptor estrogen receptor α (ERα) is pivotal for numerous processes in the cell. As a transcription factor, it regulates eukaryotic gene expression and affects cellular proliferation and differentiation in target tissues. Moreover, ERα is known for its influence on various gynecological diseases and carcinogenesis. Since its expression is often altered in diseased tissues and this alteration was found to be caused by hypermethylation of the ESR1 promotor region in cancer, including breast and colorectal cancer, the aim of this study is to elucidate if the expression of ERα is also regulated epigenetically in endometriosis and endometrial cancer.
Methods: Using real-time methylation-specific PCR (rt-MSP), we examined endometrial and endometriotic tissues as well as five endometrial cancer cell lines and compared the methylation status with the actual expression of ERα.
Results: The results of our study indicate that, though its expression is altered in endometrial and endometriotic tissue, ERα is not regulated by methylation of the promotor region in endometriosis. In contrast, three of the five endometrial cancer cell lines are methylated in the promotor region of ESR1.
Conclusions: Thus, further investigation of the connection between ERα and endometrial cancer will be the next step.
Keywords: ESR1 promotor; Endometriosis; Endometrium; Estrogen receptor α (ERα); Real-time methylation-specific PCR (rt-MSP).