High-Throughput Sequencing Approach Uncovers the miRNome of Peritoneal Endometriotic Lesions and Adjacent Healthy Tissues

Accumulating data have shown the involvement of microRNAs (miRNAs) in endometriosis pathogenesis. In this study, we used a novel approach to determine the endometriotic lesion-specific miRNAs by high-throughput small RNA sequencing of paired samples of peritoneal endometriotic lesions and matched healthy surrounding tissues together with eutopic endometria of the same patients. We found five miRNAs specific to epithelial cells – miR-34c, miR-449a, miR-200a, miR-200b and miR-141 showing significantly higher expression in peritoneal endometriotic lesions compared to healthy peritoneal tissues. We also determined the expression levels of miR-200 family target genes E-cadherin, ZEB1 and ZEB2 and found that the expression level of E-cadherin was significantly higher in endometriotic lesions compared to healthy tissues. Further evaluation verified that studied miRNAs could be used as diagnostic markers for confirming the presence of endometrial cells in endometriotic lesion biopsy samples. Furthermore, we demonstrated that the miRNA profile of peritoneal endometriotic lesion biopsies is largely masked by the surrounding peritoneal tissue, challenging the discovery of an accurate lesion-specific miRNA profile. Taken together, our findings indicate that only particular miRNAs with a significantly higher expression in endometriotic cells can be detected from lesion biopsies, and can serve as diagnostic markers for endometriosis.越来越多的研究数据表明，微小RNA（microRNAs, miRNAs）参与了子宫内膜异位症的发病机制。本研究采用全新的实验策略，通过对配对的腹膜子宫内膜异位病灶样本、匹配的健康周围组织，以及同一患者的在位子宫内膜进行高通量小RNA测序，以鉴定子宫内膜异位病灶特异性miRNAs。本研究发现5种上皮细胞特异性miRNAs——miR-34c、miR-449a、miR-200a、miR-200b及miR-141，在腹膜子宫内膜异位病灶中的表达水平显著高于健康腹膜组织。我们还检测了miR-200家族靶基因E-钙粘蛋白（E-cadherin）、ZEB1及ZEB2的表达水平，结果显示子宫内膜异位病灶中E-钙粘蛋白的表达水平显著高于健康组织。进一步评估证实，所研究的miRNAs可作为诊断标志物，用于确认子宫内膜异位病灶活检样本中子宫内膜细胞的存在。此外，我们发现腹膜子宫内膜异位病灶活检的miRNA谱在很大程度上被周围腹膜组织所掩盖，这给精准获取病灶特异性miRNA谱带来了挑战。综上，本研究结果表明，仅可从病灶活检样本中检测到在子宫内膜异位细胞中呈显著高表达的特定miRNAs，此类分子可作为子宫内膜异位症的诊断标志物。