JSI‐124 inhibits cell proliferation and tumor growth by inducing autophagy and apoptosis in murine malignant mesothelioma

Abstract

AbstractMalignant pleural mesothelioma (MPM), mainly caused by asbestos exposure, has a poor prognosis and lacks effective treatment compared with other cancer types. The intracellular transcription factor signal transducer and activator of transcription 3 (STAT3) is overexpressed and hyperactivated in most human cancers. In this study, the role of STAT3 in murine MPM was examined. Inhibition of the Janus kinase 2 (JAK2)/STAT3 pathway with the selective inhibitor JSI‐124 has an antitumor effect in murine MPM. Specifically, we demonstrated that JSI‐124 inhibits murine MPM cell growth and induces apoptotic and autophagic cell death. Exposure of RN5 and AB12 cells to JSI‐124 resulted in apoptosis via the Bcl‐2 family of proteins. JSI‐124 triggered autophagosome formation, accumulation, and conversion of LC3I to LC3II. Autophagy inhibitors, Chloroquine (CQ) and Bafilomycin A1 (Baf‐A1), inhibited autophagy and sensitized RN5 and AB12 cells to JSI‐124‐induced apoptosis. Our data indicate that JSI‐124 is a promising therapeutic agent for MPM treatment.