Abstract 1295: SJP1901, a small molecule inhibitor targeting hippo pathway by directly inhibiting TEAD palmitoylation in hippo pathway-dependent cancer
Authors: Um Jihyun , Lee Janghyun , Hwang Kwangwoo , Park Sujin , Hyun Jooyoung , Lee Dohyeong , Lee Jeongmin , Kim Li-Kyung , Back Moon Jung , Park Seong Jun , Lim Hwan Jung , Shin You-Keun , Jeung Hei-Cheul , Lee Jaewoong , Kim Hyun Tae , Park Yongbin , Kwon Hoseok , Ki Min-Hyo 
Published: July 2021

Abstract
The hippo pathway is a critical transcriptional regulator of cell growth, proliferation, and migration in cancer, furthermore,YAP-TEAD complexes act as a major role in the pathway. S-palmitoylation of cysteine residues in TEAD proteins is required for their stability and function in hippo pathway signaling. Recently, it has become manifested that the dysregulation of hippo pathway effectors (MST1/2 and LATS1/2) is involved in oncogenesis. These effectors inactivate translocation of YAP and TAZ into the nucleus. The translocation of YAP/TAZ is responsible for acting as transcriptional coactivators by binding to the transcription factor, TEADs resulting in the transcription of cancer-related genes that drive tumor growth. Since YAP/TAZ are considered to be natively unfolded and can be difficult to handle as a drug target, TEAD is regarded as an excellent therapeutic target for intervention of the hippo pathway. SJP1901 is a small molecule of TEAD inhibitor with potential as drug candidates in malignant mesothelioma and other types of cancer. Based on the results of structure-based drug design, hit compounds were synthesized and their efficacy was evaluated.The compounds effectively inhibited palmitoylation of TEAD proteins and showed remarkable efficacy in reporter gene assay using TEAD responsive element (TRE)-integrated MCF7 with nano molar IC50 concentrations. The excellent anti-tumor effect of SJP1901 was revealed via cell proliferation inhibition assay (nano molar IC50 concentrations) andanalysis of inhibited transcription activity for target genes (CTGF and CYR61) usingmalignant mesothelia cell lines (NCI-H226, NCI-H2052 and MSTO-211H) known to display hippo pathway-dependent cell growth. In addition, these compounds showed lower toxicities in normal cells such as Fa2N4, CCD-18co and WI38 (IC50&gt;10 μM). In conclusion, we obtained potent small molecules which inactivate TEAD proteins by directly inhibiting their palmitoylation. SJP1901 showed outstanding anti-cancer effects through regulating hippo pathway-mediated target genes and lower toxicitiy in normal cells. In vivo efficacy study and research to expand the indications are currently ongoing.
Citation Format: Jihyun Um, Janghyun Lee, Kwangwoo Hwang, Sujin Park, Jooyoung Hyun, Dohyeong Lee, Jeongmin Lee, Li-Kyung Kim, Moon Jung Back, Seong Jun Park, Hwan Jung Lim, You-Keun Shin, Hei-Cheul Jeung, Jaewoong Lee, Hyun Tae Kim, Yongbin Park, Hoseok Kwon, Min-Hyo Ki. SJP1901, a small molecule inhibitor targeting hippo pathway by directly inhibiting TEAD palmitoylation in hippo pathway-dependent cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1295.