KRAS signaling in malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) arises from mesothelial cells lining the pleural cavity of asbestos-exposed individuals and rapidly leads to death. MPM harbors loss-of-function mutations in BAP1, NF2, CDKN2A, and TP53, but isolated deletion of these genes alone in mice does not cause MPM and mouse models of the disease are sparse. Here, we show that a proportion of human MPM harbor point mutations, copy number alterations, and overexpression of KRAS with or without TP53 changes. These are likely pathogenic, since ectopic expression of mutant KRAS(G12D) in the pleural mesothelium of conditional mice causes epithelioid MPM and cooperates with TP53 deletion to drive a more aggressive disease form with biphasic features and pleural effusions. Murine MPM cell lines derived from these tumors carry the initiating KRAS(G12D) lesions, secondary Bap1 alterations, and human MPM-like gene expression profiles. Moreover, they are transplantable and actionable by KRAS inhibition. Our results indicate that KRAS alterations alone or in accomplice with TP53 alterations likely play an important and underestimated role in a proportion of patients with MPM, which warrants further exploration.
European Union (EU); Horizon 2020; European Research Council 2010 Starting Independent Investigator; ERC Proof of Concept 2015 (ERC-PoC-2015); German Research Society; ALTERNATIVE; German Ministry for Education and Research; German Center for Lung Research Translational Research Grant; Greek State Scholarship Foundation Program; European Union (EU); European Union Social Fund; Greek National Fund; Reinforcement of Postdoctoral Researchers-1 stand 2nd cycles; General Secretariat for Research and Innovation; Hellenic Foundation for Research and Innovation; REPSIRE European Respiratory Society Fellowship; Institut National de la Sante et de la Recherche Medicale (INSERM); Centre National de la Recherche Scientifique (CNRS); Institut de Recherche en Sante Respiratoire des Pays de la Loire; National Research Agency Programme d' Investissements d' Avenir; Pays de la Loire Region Research Program; Ligue Contrele Cancer; Chancellerie des Universites de Paris; Projekt DEAL