Abstract
The Hippo signaling pathway regulates cell fate and organ development. In the Hippo pathway, transcriptional enhanced associate domain (TEAD) which is a transcription factor is activated by forming a complex with yes-associated protein 1 (YAP1) or transcriptional coactivator with PDZ-binding motif (TAZ, also called WWTR1). Hyper-activation of YAP1/TAZ, leading to the activation of TEAD, has been reported in many cancers, including malignant pleural mesothelioma (MPM). Therefore, the YAP1/TAZ-TEAD complex is considered a novel therapeutic target for cancer treatment. However, few reports have described YAP1/TAZ-TEAD inhibitors, and their efficacy and selectivity are poor. In this study, we performed a high-throughput screening of a neurofibromin 2 (NF2)-deficient MPM cell line and a large tumor suppressor kinase 1/2 (LATS1/2)-deficient non-small-cell lung cancer cell line using a transcriptional reporter assay. After screening and optimization, K-975 was successfully identified as a potent inhibitor of YAP1/TAZ-TEAD signaling. X-ray crystallography revealed that K-975 was covalently bound to an internal cysteine residue located in the palmitate-binding pocket of TEAD. K-975 had a strong inhibitory effect against protein-protein interactions between YAP1/TAZ and TEAD in cell-free and cell-based assays. Furthermore, K-975 potently inhibited the proliferation of NF2-non-expressing MPM cell lines compared with NF2-expressing MPM cell lines. K-975 also suppressed tumor growth and provided significant survival benefit in MPM xenograft models. These findings indicate that K-975 is a strong and selective TEAD inhibitor with the potential to become an effective drug candidate for MPM therapy.