ANALYSIS OF MICRORNA EXPRESSION IN MALIGNANT PLEURAL MESOTHELIOMA, ASBESTOSIS AND BENIGN PULMONARY DISEASE: A PRELIMINARY STUDY

Objectives: To evaluate the diagnostic potential of a panel of microRNAs in plasma samples of patients with malignant pleural mesothelioma (MPM). Methods: A group of patients with pathological diagnosis of MPM were randomly selected from a prospective mesothelioma database. Similarly, a group of patients with asbestosis and one with benign pulmonary disease werechosen for comparison. A panel of miRNA including miR-16, miR-17, miR-21, miR-126 and miR-486 were evaluated. Analysis of covariance (ANCOVA) followed by Bonferroni post-hoc test was used for multiple comparisons. A Pvalue <0.05 was considered significant. Results: Fourteen patients with malignant pleural mesothelioma, 14 patients with asbestosis and 21 patients with benign pulmonary disease were studied. The expression of miR-16 (P < 0.0001), miR-17 (P < 0.0001), miR-21 (P = 0.004), miR-126 (P = 0.0016) and miR-486 (P = 0.003) was significantly lower in patients with asbestosis compared with subjects with benign pulmonary disease. The expression of miR-16 (P = 0.018), miR-17 (P = 0.024) and miR-126 (P = 0.019) was significantly lower in patients with MPM compared with patients with benign pulmonary disease. Only miR-486 was able to discriminate patients with MPM in respect to patients with asbestosis (P = 0.004). Amongstpatients with MPM, expression levels of miR-17 (P = 0.023) and miR- 486 (P = 0.015) were significantly higher in patients with epithelioid type compared to patients with sarcomatoid and biphasic type. Conclusions: the expression of miR-16, miR-17 and miR-126 was able to distinguish patients with MPM from subjects with benign pulmonary diseases. Levels of miR-17 and miR-486 were significantly higher in patients with mesothelioma epithelioid type. The available data clearly support the role of miRNAs in the aetiology of MPM, suggesting their possible use as diagnostic markers of the disease. Further large-scale studies are required to validate their usefulness in routine clinical settings.