Comparative Assessment of miR-185-5p and miR-191-5p Expression: From Normal Endometrium to High-Grade Endometrial Cancer

Endometrial cancer (EC) is a significant cause of cancer-related deaths in women. MicroRNAs (miRs) play a role in cancer development, acting as oncogenes or tumor suppressors. This study evaluated the diagnostic potential of hsa-miR-185-5p and hsa-miR-191-5p in EC and their correlation with clinical and histopathological features. A cross-sectional study analyzed formalin-fixed, paraffin-embedded tissue samples from 59 patients: 18 with EC, 21 with endometrial hyperplasia (EH), 17 with normal endometrium (NE), and 3 with endometrial polyps (EPs). Quantitative reverse transcription-polymerase chain reaction and TaqMan probes were used for miR expression analysis. The Shapiro–Wilk test was used to analyze the normal distribution of the data. Subsequently, parametric or non-parametric tests were used to evaluate the associations between the expression levels of each miR and clinical parameters. Both miRs were underexpressed in some precursor and malignant lesions compared to certain NE subtypes and benign lesions. Specifically, hsa-miR-185-5p showed underexpression in grade 3 EC compared to some NE and EH subtypes (FC: −57.9 to −8.5, <i>p</i> < 0.05), and hsa-miR-191-5p was underexpressed in EH and EC compared to secretory endometrium and EPs (FC: −4.2 to −32.8, <i>p</i> < 0.05). <i>SETD1B</i>, <i>TJP1</i>, and <i>MSI1</i> were common predicted target genes. In conclusion, hsa-miR-185-5p and hsa-miR-191-5p are underexpressed in EC tissues, correlating with histopathological grades, highlighting their potential as diagnostic biomarkers and their role as tumor suppressors in EC.