MicroRNA let-7: A promising non-invasive biomarker for diagnosing and treating external genital endometriosis

OBJECTIVE: To evaluate the possibility of using microrna let-7 and mir-9 as non-invasive biomarkers for the diagnosis and treatment of external genital endometriosis. MATERIALS AND METHODS: We explored the samples of relatively healthy individuals and patients with endometriosis. All patients had undergone laparoscopic surgical treatment after clinical and laboratory examinations. We used RNA-GO to obtain total RNA from endometriosis samples excised by laparoscopic method. Next step involved reverse transcription for microRNA let-7 and mir-9. Correlation-regression analysis was performed using Mann-Whitney-Wilcoxon method. Subsequently, receiver operating characteristic analysis was conducted to determine the possibility of using let-7 microRNA for non-invasive detection of endometriosis. The results of the analysis in all groups were tested considering the normality of statistical distribution. RESULTS: Mann-Whitney analysis showed that the difference in mir-9 mRNA between the groups with and without endometriosis, as well as between the groups with more clinically and histologically severe and mild endometriosis, was statistically insignificant. In addition, a significant difference was noted regarding let-7 microRNA between the groups with and without endometriosis, as well as between the groups with more clinically and histologically severe and mild endometriosis. Comparison with cancer antigen-125 (CA-125) showed that let-7 microRNA was a more specific test than CA-125. CONCLUSION: MicroRNA let-7 had the best parameters (sensitivity, specificity, and predictive value of positive and negative results) among the biomarkers studied. These biomarkers may be used for early and sometimes preclinical diagnosis of endometriosis.