LIMK Inhibition and Metformin Block Mitochondrial Transfer Overcoming Macrophage Driven Therapy Resistance in Acute Myeloid Leukaemia

Nwarunma, E.; Miari, K. E.; Papadopoulou, A.; Corradini, S.; Watt, G.; Hurwitz, S.; Fourfouris, T.; Lee, K. J.; Bubnova, X.; Briggs, R.; Goodyear, C. S.; Simakou, T.; Doohan, M.; MacDonald, L.; Kurowska-Stolarska, M.; Humpton, T. J.; Williams, M. T.; Campbell, V. L.; Forrester, L. M.; Mills, K.; Lappin, K.; Ferro, V. A.; Kim, Y.-m.; Wheadon, H.

doi:10.64898/2026.02.03.702377

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bioRxiv · 10.64898/2026.02.03.702377

LIMK Inhibition and Metformin Block Mitochondrial Transfer Overcoming Macrophage Driven Therapy Resistance in Acute Myeloid Leukaemia

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Abstract

Chemoresistance is a major contributor to poor clinical outcomes in AML patients and can arise from interactions between AML cells and the bone marrow microenvironment (BME). How immune cells, particularly macrophages (M{varphi}s), facilitate this process requires better clarification. This study shows that M2-like M{varphi}s protect AML cells from apoptosis induced by daunorubicin (DNR) and cytarabine (Ara-C). This protection occurs via co-culture and is linked to enhanced mitochondrial transfer from M{varphi}s to AML cells. M{varphi}s interacted with AML cells via tunneling nanotube (TNT)-like structures. Furthermore, inhibition of mitochondrial transfer using cytochalasin B reduced the protective effect, indicating that mitochondria mediate this process. M{varphi}s transferred functional mitochondria to AML cells as evidenced by enhanced metabolic capacity and reduced reactive oxygen species levels in AML cells under chemotherapy stress. TH-257 (LIMK inhibitor) and metformin blocked mitochondrial transfer and M{varphi}-driven chemoprotection. Moreover, increased transcript expression levels of RhoC and cofilin correlate with inferior overall survival in AML patients. These findings suggest that M2-like M{varphi}s contribute to chemoresistance through TNT-mediated mitochondrial transfer and the LIMK-Cofilin pathway, identifying potential therapeutic targets to circumvent chemoresistance in AML.

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Nwarunma, E., Miari, K. E., Papadopoulou, A., Corradini, S., Watt, G., Hurwitz, S., Fourfouris, T., Lee, K. J., Bubnova, X., Briggs, R., Goodyear, C. S., Simakou, T., Doohan, M., MacDonald, L., Kurowska-Stolarska, M., Humpton, T. J., Williams, M. T., Campbell, V. L., Forrester, L. M., Mills, K., Lappin, K., Ferro, V. A., Kim, Y.-m., Wheadon, H.. 2026-02-05. LIMK Inhibition and Metformin Block Mitochondrial Transfer Overcoming Macrophage Driven Therapy Resistance in Acute Myeloid Leukaemia. https://doi.org/10.64898/2026.02.03.702377

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