Aurora kinase A drives non-canonical YAP1/TAZ crosstalk to sustain primary resistance to anti-EGFR therapies in colorectal cancer

Abstract

Anti-epidermal growth factor receptor (EGFR) therapies are the most recommended first-line treatment for RAS/RAF wild-type unresectable metastatic colorectal cancer (CRC) according to the European Society for Medical Oncology guidelines. However, primary resistance renders this treatment ineffective for almost 40% of patients. Our previous work identified Aurora kinase A (AURKA) as a key resistance driver through non-canonical, Hippo-independent Yes-associated protein 1 (YAP1) activation. However, the role of the other main Hippo coactivator, transcriptional coactivator with PDZ-binding motif (TAZ), in this resistance mechanism remains unexplored. By integrating preclinical in vitro and in vivo models, including cell lines and patient-derived xenografts, with RNA sequencing, we investigated the impact of TAZ overexpression in cetuximab resistance driven by the AURKA/YAP1 axis. Our findings reveal that TAZ overexpression sustains YAP1-mediated resistance and stemness. Even under YAP1 suppression, TAZ-overexpressing cells remain unresponsive to anti-EGFR therapies, whereas dual YAP1/TAZ silencing restores sensitivity. Treatment with alisertib, a phase III AURKA inhibitor, simultaneously destabilizes YAP1 and TAZ, restoring anti-EGFR efficacy by suppressing stemness. Transcriptomic analyses further show that AURKA inhibition and dual YAP1/TAZ suppression disrupt stem-like traits and reveal transcriptional deregulations affecting nucleotide metabolism. These findings demonstrate that AURKA orchestrates YAP1/TAZ crosstalk, which is crucial for driving stemness and resistance to anti-EGFR therapies, highlighting AURKA inhibitors as a promising strategy to enhance anti-EGFR therapies in metastatic CRC.