Cooperation between the Hippo and MAPK pathway activation drives acquired resistance to TEAD inhibition II. Cooperation between the Hippo and MAPK pathway activation drives acquired resistance to TEAD inhibition II

TEAD transcription factors (TEAD1-4) serve as the primary effectors of the Hippo signaling pathway in various cancers. There has been significant progress in the development of therapeutic strategies aimed at disrupting the interaction of TEAD with its coactivators YAP/TAZ. However, targeted therapy leads to the emergence of resistance which poses a barrier to achieving complete cures. Currently, the underlying mechanism of resistance to TEAD inhibition in cancers remains unexplored. We uncover that upregulation of the AP-1 transcription factors, along with restored YAP/TEAD activity, drives resistance to GNE-7883, a pan-TEAD and allosteric TEAD inhibitor. Acute GNE-7883 treatment abrogates YAP binding and attenuates FOSL1 activity but compensation by increased MAPK pathway activity remains insufficient for cell survival. In contrast, TEAD inhibitor resistant cells are able to restore YAP and TEAD occupancy and acquire additional FOSL1 binding sites, leading to increased chromatin accessibility at AP-1 motifs. Resistant cells undergo transcriptional reprogramming to acquire a mesenchymal-like cell state and sustained MAPK activity. We uncover a dependence on the MAPK pathway in the TEAD inhibitor resistant cells, further highlighting the key role of MAPK pathway inhibitors, such as Cobimetinib and Belvarafenib to mitigate resistance mechanisms to TEAD inhibition in Hippo pathway dependent cancers. This study describes a clinically relevant interplay between the Hippo and MAPK pathway in cancers and offers a promising avenue to address TEAD inhibitor resistance in the clinic. Overall design: To investigate the mechanism involved in TEAD acquired resistance, we developed TEADi resistant cell lines. In order to map interaction between YAP1, TEAD1 and FOSL1 and their DNA binding sites, we performed chromatin profiling (CUT&RUN) from TEAD inhibitor sensitive cells incubated with DMSO or TEAD inhibitor GNE-7883 and TEAD inhibitor resistant cells incubated with TEAD inhibitor GNE-7883.

TEAD转录因子（TEAD1-4）是多种癌症中Hippo信号通路的核心效应分子。针对破坏TEAD与其共激活因子YAP/TAZ相互作用的治疗策略研发已取得显著进展。然而，靶向治疗会诱导耐药性产生，成为实现癌症完全治愈的关键障碍。目前，癌症中TEAD抑制剂耐药的潜在分子机制仍未被阐明。
本研究发现，AP-1转录因子的上调伴随YAP/TEAD活性的恢复，可促使癌细胞对泛TEAD变构TEAD抑制剂GNE-7883产生耐药性。短期GNE-7883处理可消除YAP的染色质结合并减弱FOSL1的活性，但MAPK通路活性增强所带来的代偿不足以维持细胞存活。与之相反，TEAD抑制剂耐药细胞能够恢复YAP与TEAD的染色质结合水平，并获得额外的FOSL1结合位点，进而增强AP-1基序区域的染色质开放程度。耐药细胞会发生转录重编程，获得间质样细胞表型并维持MAPK通路的持续激活。
本研究进一步证实，TEAD抑制剂耐药细胞依赖MAPK通路，凸显了MAPK通路抑制剂（如考比替尼（Cobimetinib）和贝勒伐非尼（Belvarafenib））在缓解Hippo通路依赖型癌症中TEAD抑制剂耐药机制方面的关键作用。本研究揭示了癌症中Hippo与MAPK通路之间具有临床相关性的相互调控关系，为临床解决TEAD抑制剂耐药问题提供了极具潜力的干预方向。
实验设计：为探究TEAD抑制剂获得性耐药的分子机制，本研究构建了TEADi耐药细胞系。为绘制YAP1、TEAD1与FOSL1及其DNA结合位点的相互作用图谱，本研究对样本进行染色质谱分析（CUT&RUN）：实验组包括经DMSO或TEAD抑制剂GNE-7883孵育处理的TEAD抑制剂敏感细胞，以及经TEAD抑制剂GNE-7883孵育处理的TEAD抑制剂耐药细胞。