Genetics and Epigenetics of Mesothelioma

The definition of the mesothelioma genome is expected to have a great impact toward the development of new drugs and therapeutic approaches with a view to precision medicine. A few studies reported that the malignant pleural mesothelioma (MPM) genomic landscape is characterized by a much greater number of genomic losses than point mutations. Inactivating gene fusions, copy losses, and protein-truncating variants (PTVs) mostly affect tumor suppressor genes, above all BAP1, NF2, CDKN2A, and SETD2. Some of them may be exploited to design novel therapeutic strategies. Germline mutations in some of these genes represent MPM-predisposing risk factors. These mutations require a second hit, i.e., asbestos exposure, to induce carcinogenesis. The most studied of these genes is BAP1. Germline mutations in other tumor suppressor genes, mostly involved in DNA repair, have also been identified in about 10% of MPM patients. These patients are more sensitive to asbestos exposure than those who do not carry such mutations and may benefit of specific treatments. Additionally, epigenetic mechanisms, such as methylation or miRNA alterations, may modify gene expression and drive carcinogenesis. The same abnormalities may be used as disease biomarkers or therapeutic targets.