WASP activation by BM011 triggers mitochondrial collapse and aldolase-dependent glycolytic vulnerability in lymphoma

Background. BM011 is the first-in-class WASP (Wiskott-Aldrich Syndrome Protein) activator (Spriano et al, 2024). WASP regulates cytoskeletal remodeling, immune synapse formation, vesicle trafficking, and mechano-metabolic coupling. Aberrant actin dynamics and rewiring of the WASP pathway contribute to proliferation, metabolic flexibility, and stress resistance in lymphomas and other cancers. Here, we investigated the mechanism of action of BM011 by combining transcriptomics, proteomics, and a genome-wide CRISPR-Cas9 knockout screen in lymphoma cells treated with the compound. Methods. JEKO1 mantle cell lymphoma cells were treated with BM011 for 8h and analyzed by RNA-Seq and mass spectrometry (MS). A genome-wide CRISPR-Cas9 knockout screen was conducted following 14-day exposure to BM011. Results. Proteomics revealed a strong downregulation of mitochondrial import and respiratory chain proteins in BM011-treated cells, while many RNAs coding for the same molecules were upregulated, consistent with an attempt to compensate for mitochondrial stress. Similarly, ribosomal proteins decreased, while ribosomal transcripts increased, suggesting a proteotoxic stress response and a translational offset. Stress-response genes (e.g., HSPA family), cytoskeleton, and apoptotic pathways were strongly induced, indicating proteotoxic pressure, cytoskeleton remodeling, and apoptosis induction following cytoskeletal forcing. At the genetic screen, the loss of many mitochondrial respiratory chain genes sensitized cells to BM011, confirming their importance in mitigating BM011-induced mitochondrial collapse. In contrast, the knockout of FUNDC2 and TIMM23, not part of the mitochondrial respiratory chain, conferred resistance, likely due to the interruption of mitochondrial quality control and decreased apoptosis upon BM011 treatment. The genetic screen also revealed a divergent vulnerability to glycolysis. Knockout of genes coding for enzymes of the upper glycolytic process (HK2, PFKM, PFKL, GPI, PFKFB3) conferred resistance, while knockout of genes coding for proteins in the lower part of glycolysis (PGK1, ENO1, PKM, PFKFB4) increased sensitivity. This pointed to aldolase and the fructose-1,6-bisphosphate node as a critical metabolic point. Aldolase can indeed bind to F-actin and WASP, inhibiting actin polymerization. Additionally, an excess of fructose-1,6-bisphosphate (F16bP) inhibits aldolase binding to F-actin. We proved that F16bP supplementation or aldolase inhibition increased the sensitivity of BM011 in otherwise resistant lymphoma cells. Conclusion. BM011-driven activation of WASP induces cytoskeletal stress, mitochondrial import failure, and a proteotoxic response, with upper-glycolysis and aldolase acting as a metabolic safety valve. These reveal druggable metabolic-cytoskeletal vulnerabilities in lymphoma.