Abstract 5557: Deciphering the interplay of β-catenin/YAP signaling and alveolar lineage plasticity during targeted therapy in non-small cell lung cancer

Abstract Molecularly targeted therapies have significantly improved clinical outcomes by directly addressing oncogenic driver mutations in genes such as EGFR. However, despite their initial success, long-term patient survival remains limited due to the emergence of drug tolerance and resistance. This study investigates the molecular mechanisms underlying drug tolerance in response to targeted therapies in non-small cell lung cancer (NSCLC). Using single-cell RNA sequencing of oncogene-driven human NSCLCs at the residual disease (RD) state during active targeted therapy, we observed an enrichment of an alveolar type I/II (AT1/2) mixed lineage program in surviving cancer cells, resembling an alveolar cell-like state. This transition is characterized by increased expression of WNT3A/4 ligands, FZD2 receptors, β-catenin signaling, and AT1/2 signatures in RD cells. Consistent with these clinical observations, preclinical models of drug-tolerant persister (DTP) cells exhibited elevated AT1/2-like transcriptional signatures and target gene expression associated with β-catenin and YAP signaling. Further analysis revealed the formation of a stable nuclear protein complex between β-catenin and YAP in DTP cells, which appears to play a critical role in sustaining drug tolerance. Disrupting the expression and stability of the β-catenin/YAP complex, either through knockdown of these genes or by using Tankyrase inhibitors (e.g. XAV-939 or IWR1) to regulate the β-catenin destruction complex, re-sensitized DTP cells to the EGFR inhibitor Osimertinib. In xenograft mouse models, the combination of Osimertinib with a Tankyrase inhibitor significantly improved tumor growth inhibition compared to Osimertinib alone. This therapeutic strategy also led to a notable reduction in AT1/2 gene signatures, a decrease in nuclear β-catenin and YAP protein expression, reduced stability of these proteins, and suppression of their interaction, further supporting its potential in overcoming drug tolerance. Additionally, we identified specific domains within both β-catenin and YAP proteins that are essential for their interaction. This interdependence underscores the critical roles of β-catenin and YAP in maintaining DTP cell survival and driving alveolar cell-like lineage plasticity. Our findings shed light on the interplay between β-catenin/YAP signaling and alveolar cell-like lineage signatures in residual cancer states. By targeting this axis, we propose a novel therapeutic approach to overcome drug tolerance and improve clinical outcomes for patients with NSCLC undergoing targeted therapy. Citation Format: Yu-Ting Chou, Wei Wu, D. Lucas Kerr, Victor Olivas, Macey Slota, Trever G. Bivona. Deciphering the interplay of β-catenin/YAP signaling and alveolar lineage plasticity during targeted therapy in non-small cell lung cancer [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 5557.