Cooperation between the Hippo and MAPK pathway activation drives acquired resistance to TEAD inhibition [CUT&RUN]. Cooperation between the Hippo and MAPK pathway activation drives acquired resistance to TEAD inhibition [CUT&RUN]

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. We then performed gene expression profiling using data obtained from TEAD inhibitor sensitive cells incubated with DMSO or TEAD inhibitor GNE-7883 and TEAD inhibitor resistant cells incubated with DMSO or TEAD inhibitor GNE-7883.

TEAD转录因子（TEAD transcription factors，TEAD1-4）是多种癌症中Hippo信号通路（Hippo signaling pathway）的核心效应蛋白。靶向破坏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，此类靶向治疗会诱导耐药性产生，成为实现完全临床治愈的关键障碍。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（AP-1 transcription factors）的上调以及YAP/TEAD活性的恢复，会驱动细胞对GNE-7883——一种泛TEAD变构抑制剂——产生耐药性。急性GNE-7883处理会消除YAP与染色质的结合并减弱FOSL1的转录活性，但此时由MAPK信号通路（MAPK pathway）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和TEAD的染色质结合，并获得额外的FOSL1结合位点，进而提升AP-1基序处的染色质开放性。耐药细胞会发生转录重编程，获得间充质样细胞表型并维持持续的MAPK信号通路活性。

本研究进一步揭示了TEAD抑制剂耐药细胞对MAPK信号通路的依赖性，凸显了MAPK通路抑制剂（如Cobimetinib和Belvarafenib）在缓解Hippo通路依赖型癌症中TEAD抑制剂耐药机制方面的核心作用。本研究阐明了癌症中Hippo与MAPK信号通路之间具有临床相关性的交互调控关系，并为临床中解决TEAD抑制剂耐药问题提供了极具前景的干预策略。

实验设计：为探究TEAD获得性耐药的潜在分子机制，我们构建了TEAD抑制剂耐药细胞系。随后，我们对四类样本进行基因表达谱分析：经二甲基亚砜（dimethyl sulfoxide, DMSO）或TEAD抑制剂GNE-7883处理的TEAD抑制剂敏感细胞，以及经DMSO或GNE-7883处理的TEAD抑制剂耐药细胞。