cfDNA Methylation Profiles and T-Cell Differentiation in Women with Endometrial Polyps

DNA methylation is a part of the regulatory mechanisms of gene expression, including chromatin remodeling and the activity of microRNAs, which are involved in the regulation of T-cell differentiation and function. However, the role of cfDNA methylation in T-cell differentiation is entirely unknown. In patients with endometrial polyps (EPs), we have found an imbalance of T-cell differentiation and an aberrant cfDNA methylation profile, respectively. In this study, we investigated the relationship between cfDNA methylation profiles and T-cell differentiation in 14 people with EPs and 27 healthy controls. We found that several differentially methylated genes (DMGs) were associated with T-cell differentiation in people with EPs (ITGA2-Naïve CD4, r = −0.560, p = 0.037; CST9-EMRA CD4, r = −0.626, p = 0.017; and ZIM2-CM CD8, r = 0.576, p = 0.031), but not in healthy controls (all p > 0.05). When we combined the patients’ characteristics, we found a significant association between ITGA2 methylation and polyp diameter (r = 0.562, p = 0.036), but this effect was lost when adjusting the level of Naïve CD4 T-cells (r = 0.038, p = 0.903). Moreover, the circulating sex hormone levels were associated with T-cell differentiation (estradiol-Naïve CD4, r = −0.589, p = 0.027), and the cfDNA methylation profile (testosterone-ZIM2, r = −0.656, p = 0.011). In conclusion, this study has established a link between cfDNA methylation profiles and T-cell differentiation among people with EPs, which may contribute to the etiology of EPs. Further functional studies are warranted.