MicroRNA-98 is a prognostic factor for asbestos-induced mesothelioma

Malignant pleural mesothelioma (MPM) is a type of cancer characterized by a short survival time and poor prognosis. Malignant pleural mesothelioma is most frequently associated with exposure to asbestos and other elongated mineral fibers. The aim of this study was to examine molecular differences between asbestos-exposed and non-exposed MPM patients and assess prognostic significances of molecular factors. Clinical and genetic data were downloaded from Cancer Genome Atlas. To identify the molecular differences, Significant Analysis of Microarray method was used. Prognostic significances of differentially expressed genes were confirmed by using Kaplan–Meier curve with the Log-Rank test. Although mRNAs did not exhibit any significant differences between the two patient groups, nine miRNAs were found to be down-regulated in the asbestos-exposed group. The top five pathways most relevant to the selected miRNAs were extracted through pathway enrichment analysis. Survival analysis revealed that high expression of only hsa-miR-98 was significantly associated with poor prognosis in patients with asbestos-exposed MPM. Evidence suggests that management of the aggressiveness and progression of asbestos-induced MPM may require high levels of hsa-miR-98 due to its tumor-suppressive role. This study might be helpful in enhancing our understanding of the biological mechanisms underlying asbestos-induced MPM and for acquiring greater insights into targeted therapy. <b>Abbreviations</b>: FDR: false discovery rate; MM: malignant mesothelioma; MPM: malignant pleural mesothelioma; mRNA: messenger RNA; miRNA: microRNA; SAM: significance analysis of microarrays; TCGA: the cancer genome atlas