IMB5023: Dual suppression of microtubule assembly and STAT3 signaling overcomes chemoresistance and activates antitumor immunity.

Microtubule-targeting agents constitute a cornerstone of cancer chemotherapy, yet drug resistance remains a major challenge. Signal transducer and activator of transcription-3 (STAT3) inhibition may potentiate chemosensitivity and circumvent resistance mechanisms. During a phenotypic screen of anticancer agents, a small-molecule compound IMB5023 emerged as a promising candidate. In the present work, we report its antitumor efficacy and mechanism of action. IMB5023 exhibited cytotoxicity across multiple cancer cell lines, inducing pyroptosis in gasdermin E-positive cells and apoptosis in gasdermin E-negative cells. Transcriptomic profiling revealed that IMB5023 targeted centrosome-related pathway and impaired mitotic spindle assembly. Immunofluorescence analysis revealed concentration-dependent effects: multipolar spindle formation at a low concentration (1 μM) and microtubule network disruption at a higher concentration (10 μM). Furthermore, IMB5023 suppressed STAT3 pathway in vitro and overcame multidrug resistance by downregulating drug efflux pump ATP-binding cassette sub-family G member 2 (ABCG2) and anti-apoptotic protein B-cell lymphoma-extra large (Bcl-XL). Notably, IMB5023 triggered immunogenic cell death and enhanced dendritic cell phagocytosis. In vivo, IMB5023 inhibited tumor growth by 52%. Tumor histopathology confirmed centrosome declustering and STAT3 pathway inhibition. Collectively, IMB5023 concurrently disrupts microtubules and inhibits STAT3 pathway. This dual mechanisms of action positions IMB5023 as a promising therapeutic candidate, particularly for resistant malignancies.