Abstract 6377: TEAD-targeting small molecules induce a cofactor switch to regulate the Hippo pathway

Abstract The Hippo signaling pathway is a major regulator of cellular growth and is frequently deregulated in cancer. TEAD proteins are the main transcriptional effectors of the Hippo pathway and a pharmacological target in oncology. Most TEAD-targeting small molecules act by binding to the conserved lipid binding pocket of TEAD and allosterically disrupting interaction between TEAD and the oncogenic transcriptional activators YAP and TAZ. However, the molecular details of how TEAD-binding small molecules function beyond YAP and TAZ is not fully understood. Using unbiased, mass spectrometry-based proteomic profiling we find an alternative mechanism for TEAD lipid pocket-binding molecules whereby certain sulfonamide-containing compounds act as molecular glues to induce the TEAD interaction with the transcriptional repressor VGLL4. The chemically induced VGLL4-TEAD interaction occurs in a variety of cell types and can be biochemically recapitulated in vitro. Additionally, small molecule activation of VGLL4-TEAD complexes counteracts YAP activity at chromatin to repress pro-growth gene networks, including genes involved in cellular proliferation and mechanosignaling. Thus, enhanced interaction between TEAD and VGLL4 stimulates a small molecule-mediated cofactor switch from YAP to VGLL4. Cells that do not express VGLL4 are not sensitive to this class of compounds, but become sensitive upon exogenous overexpression of VGLL4. Additionally, genetic deletion of VGLL4 causes resistance to these molecules in cells and in in vivo tumors. These results demonstrate that VGLL4 is the required factor that mediates an anti-proliferative response to these sulfonamide-containing TEAD lipid pocket-binding compounds. Our data reveal a suite of molecules that act as molecular glues toward the repressive VGLL4-TEAD interaction and open up new understandings for curbing the oncogenic activity of Hippo pathway deregulation. Citation Format: Alissa D. Guarnaccia, Thijs J. Hagenbeek, Wendy Lee, Noelyn Kljavin, Meena Choi, Gözde Ulas, Vasumathi Kameswaran, Daniel Le, Sayantanee Paul, Samir Vaidya, Jason R. Zbieg, James J. Crawford, Bence Daniel, Anwesha Dey, Jennie R. Lill. TEAD-targeting small molecules induce a cofactor switch to regulate the Hippo pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 6377.