2Eskisehir Osmangazi University, Faculty of Medicine
3University of Health Sciences, Gulhane Faculty of Medicine
AIM: To determine case-control differences in tissue miRNA expression and to quantify their ability to distinguish meningioma from nontumor dura. MATERIAL and METHODS: Tissue samples from 45 intracranial meningioma cases (WHO grade I, n = 22; grade II, n = 23) and 26 dura controls were analyzed. miRNA expression levels were measured by quantitative real-time PCR (qRT-PCR), normalized to U6, and relative expression levels were calculated using the 2−ΔΔCt method. Group and grade comparisons were performed using appropriate parametric or nonparametric tests. Diagnostic performance was evaluated using receiver operating characteristic (ROC) and area under the curve (AUC) values, with optimal cut-off points determined by the Youden index. Sensitivity and specificity were reported. RESULTS: Compared with controls, meningioma tissues showed significant downregulation of miR-221, miR-143, and miR-22 (all p < 0.001), whereas miR-145 showed borderline significance (p = 0.052). Diagnostic discrimination was highest for miR-221 (AUC, 0.912; cut-off, ≤0.19; sensitivity, 91.11%; specificity, 88.46%), followed by miR-143 (AUC, 0.810; cut-off, ≤0.24; sensitivity, 71.11%; specificity, 92.31%) and miR-22 (AUC, 0.771; cut-off, ≤0.36; sensitivity, 82.22%; specificity, 65.38%). No significant differences in expression were observed between grade I and grade II tumors for any miRNA. CONCLUSION: Tissue miR-221, miR-143, and miR-22 are consistently downregulated in intracranial meningioma and demonstrate clinically meaningful diagnostic performance, with miR-221 showing the highest discriminatory accuracy. These findings support the potential integration of miRNA assays into tissue-based diagnostics and warrant multicenter validation to refine cut-off values and evaluate prognostic utility.