EMT emerges as a common gynecologic disease with complicated pathogenesis, which mainly impacts women of reproductive age . miRNAs are implicated in the nosogenesis of EMT and can be proposed as potential markers in EMT . This study evaluated the diagnostic efficacy of miR-17-5p and miR-424-5p for EMT.
Aberrant levels of miRNAs are implicated in the occurrence and progression of EMT  and proposed as biomarkers for early diagnosis and prediction of EMT . First, the RT-qPCR revealed decreased expressions of miR-17-5p and miR-424-5p in women with EMT. Consistently, increasing reports unveil that miR-17-5p is weakly expressed in EMT patients, indicating its potential utility in clinical diagnosis of EMT [26, 27]. miR-424-5p is involved in the development of EMT and is lowered in EMT lesions [14, 28]. Thus, weak expressions of miR-17-5p and miR-424-5p in EMT patients may be potential biomarkers.
Next, we further investigated the diagnostic value of miR-17-5p and miR-424-5p for EMT. For the diagnosis of EMT, the AUC of miR-17-5p was 0.865 and the cutoff value was 0.890 (91.3% sensitivity and 85% specificity). The AUC of miR-424-5p was 0.737 and the cutoff value was 0.915 (98.8% sensitivity and 61.2% specificity). AUC was 0.939 and the cutoff value was 2.205 (93.8% sensitivity and 88.7% specificity) for combined diagnosis of miR-17-5p and miR-424-5p. Previous studies also elicit that the combination of several different miRNAs, with improved sensitivity and specificity, has elevated diagnostic accuracy relative to individual miRNA [15, 29]. Altogether, miR-17-5p and miR-424-5p both could be considered as biomarkers for EMT, and their combination had amplified this diagnostic efficacy.
Infertility, chronic pelvic pain, and dysmenorrhea are primary symptoms of EMT . Initially, the analysis of general data and clinic characteristics of EMT patients and healthy women unraveled the elevated proportions of dysmenorrhea, infertility, and pelvic pain in EMT patients. EMT individuals usually have a prolonged history of dysmenorrhea , and 30–50% of women with EMT also suffer from pelvic pain and infertility . These clinical parameters could assist the diagnosis of EMT. Moreover, Pearson correlation analysis demonstrated a remarkable inverse correlation between miR-17-5p and miR-424-5p expressions with dysmenorrhea, infertility, pelvic pain, and rASRM stage in women with EMT. miR-17-5p is related to tubal factor infertility . miR-424 is involved in the human estrogen receptor and progesterone receptor pathways . There are limited studies about the relationship of miR-17-5p and miR-424-5p levels with clinical indicators in EMT patients. Our results initially identified the strong association of miR-17-5p and miR-424-5p with EMT.
EMT is also defined as a chronic inflammatory disorder, and EMT-related pain often results from inflammation . The abnormal expression of inflammatory factor IL-4 occurs in EMT patients . IL-6 is a potential indicator for EMT and is positively related to the disease stage . Angiogenesis is of great importance for the engraftment and development of endometriotic lesions . VEGFA is an effective angiogenic factor and is regarded as a leading element in uterine angiogenesis . Hence, we investigated the relationship of miR-17-5 and miR-424-5p with VEGFA, IL-4, and IL-6. Firstly, the ELISA unveiled the increased expressions of VEGFA, IL-4, and IL-6 in the serum of EMT patients. Similarly, VEGFA is also enhanced in the peritoneal fluid of EMT patients . The previous studies have illustrated the increased concentration of IL-4 and IL-6, and the levels will increase as the disease progression [41–43]. Later, Pearson analysis revealed that miR-17-5p and miR-424-5p were negatively related with VEGFA, IL-4, and IL-6 respectively in EMT. Furthermore, the binding relationship of miR-17-5p and miR-424-5p with VEGFA was identified. miR-17-5p is an inflammation-associated miRNA and its overexpression can suppress the lipopolysaccharide-induced inflammatory response, including IL-6 level . Consistently, there is a negative correlation between miR-17 level with IL-4 and IL-6 in EMT . VEGFA is a target of miR-17-5p and miR-17-5p can repress cell migration, proliferation, and invasion in EMT by directly inhibiting VEGFA expression . miR-424-5p upregulation leads to the reduced IL-6 level . miR-424 is inversely linked with the levels of serum Il-4 and IL-6 . miR-424-5p can bind to the VEGFA mRNA and miR-424-5p overexpression significantly reduces the expression of VEGFA protein in primary cells cultured from EMT patients ; PMID: 24608518). Briefly, miR-17-5p and miR-424-5p could regulate EMT by targeting VEGFA.
In conclusion, this study first determined the expression of miR-424-5p in the serum of EMT patients and explored the diagnostic efficacy of miR-17-5p combined with miR-424-5p expressions for EMT using the ROC curve. Moreover, we analyzed the correlation of miR-17-5p and miR-424-5p levels with clinical indicators in EMT patients by Pearson correlation to provide a new entry point for clinical judgment. However, this study only investigated these two miRNAs. In addition, our study included a small number of cases and events. Addressing these deficiencies requires us to carry out the study of multiple miRNAs with significant expression differences, and expand the sample size to enhance the reliability of results. Furthermore, prognostic studies can be continued to further clarify the diagnostic value of miR-17-5p and miR-424-5p. The regulatory mechanism of miR-17-5p and miR-424-5p to target VEGFA in EMT is also worth exploring.