Targeting the ZMYM2-ANXA9 Axis with FLT3 Inhibitor G749 Overcomes Oxaliplatin Resistance in Colorectal Cancer

<b>Background:</b> Chemoresistance and tumor recurrence remain major obstacles in colorectal cancer (CRC) therapy. Elucidating the molecular mechanisms underlying treatment resistance is critical for improving therapeutic outcomes. <b>Methods</b>: We analyzed transcriptomic profiles from public datasets (TCGA and GSE39582) to identify differentially expressed genes associated with a poor response to neoadjuvant chemotherapy in CRC patients. Among 298 candidate genes, <i>ANXA9</i> emerged as significantly overexpressed in chemoresistant tumors and associated with a poor prognosis. These findings were further validated in an independent cohort of 146 Stage III CRC patients using immunohistochemistry and survival analysis. The expression of <i>ANXA9</i> was evaluated in oxaliplatin acquired-resistant CRC cell lines via qPCR and Western blot. Functional studies, including RNA interference, colony formation, apoptosis assays, and drug sensitivity testing, were performed in vitro and in vivo to assess the role of <i>ANXA9</i>. A high-throughput drug screen identified G749, a <i>FLT3</i> inhibitor, as a potential therapeutic agent. <b>Results:</b><i>ANXA9</i> expression was significantly elevated in non-responders to chemotherapy and oxaliplatin-resistant CRC cell lines. The knockdown of <i>ANXA9</i> reduced proliferation and enhanced oxaliplatin sensitivity. G749 was found to suppress <i>ANXA9</i> expression in a dose-dependent manner and inhibit CRC cell growth in vitro and in patient-derived organoids. In a CRC xenograft mouse model, G749 reduced the tumor burden without observable toxicity. Mechanistically, we identified <i>ZMYM2</i> as a transcriptional regulator of <i>ANXA9</i>. ChIP-qPCR confirmed <i>ZMYM2</i> binding to the <i>ANXA9</i> promoter, especially in resistant cells. Silencing <i>ZMYM2</i> suppressed tumor cell growth and restored chemosensitivity. <b>Conclusions:</b> The <i>ZMYM2-ANXA9</i> signaling axis drives chemoresistance and tumor progression in CRC. <i>FLT3</i> inhibition by G749 effectively downregulates <i>ANXA9</i> and sensitizes tumors to chemotherapy, highlighting a novel therapeutic approach for chemoresistant CRC.