Dannenberg, A. J. | bioRxiv Science

bioRxiv2026

Evexomostat (SDX-7320), a Methionine Aminopeptidase Type 2 (METAP2) Inhibitor, Stimulates Weight Loss and Inhibits Obesity-Accelerated Tumor Growth

Obesity and diabetes are associated with worse prognosis for numerous malignancies. Both insulin resistance and altered levels of adipokines may explain the link between obesity and tumor progression. In preclinical models, METAP2 inhibitors induce weight loss and possess anti-tumor activity, but their effects on obesity-accelerated tumor growth are unknown. Here, we investigated the effects of SDX-7320, a novel polymer-conjugated METAP2 inhibitor, on obesity and obesity-accelerated tumor growth. The anti-obesity and metabolic effects of SDX-7320 were evaluated in diet-induced obese (DIO) mice. Pharmacokinetic-pharmacodynamic relationships for SDX-7320 and the active moiety SDX-7539, a fumagillin class METAP2 inhibitor, were assessed in DIO rats. Anti-tumor efficacy of SDX-7320 was assessed in syngeneic models of obesity-accelerated tumor growth. The anti-tumor efficacy of SDX-7320 and tirzepatide, a weight loss agent, were compared in DIO mice with MC38 tumors. Treatment with SDX-7320 stimulated weight loss in obese mice, increased insulin sensitivity, decreased plasma leptin, and increased plasma adiponectin. Pharmacokinetic-pharmacodynamic analysis showed greater anti-obesity efficacy in response to SDX-7320 than SDX-7539. SDX-7320 significantly attenuated obesity-accelerated tumor growth in three different models (B16F10, EO771, MC38). RNA-Seq analysis of MC38 tumors indicated that SDX-7320 suppressed expression of cell cycle genes (decreased G2M checkpoint and E2F target pathways) and increased expression of host immune response genes (elevated interferon alpha- and gamma-response pathways). In obese mice, SDX-7320 led to significantly greater MC38 tumor growth inhibition than tirzepatide, but caused less weight loss. Plasma metabolomics revealed non-overlapping effects of SDX-7320 and tirzepatide, consistent with different mechanisms of action. Taken together, we have shown for the first time that a METAP2 inhibitor attenuates obesity-accelerated tumor growth. Mechanistically, SDX-7320-mediated tumor growth inhibition likely results from both direct anti-tumor effects (given the observed intratumoral changes in the expression of cell cycle and immune response genes), and indirect effects on the host including weight loss, decreased adipose mass, improved insulin sensitivity and normalization of plasma leptin and adiponectin levels. The fact that SDX-7320 caused greater tumor growth inhibition than tirzepatide, yet caused less weight loss, suggests that direct anti-tumor effects significantly contribute to the anti-tumor activity of SDX-7320.

cancer biology↗

bioRxiv2023

Submitochondrial Protein Translocation Upon Stress Inhibits Thermogenic Energy Expenditure

Mitochondria-rich brown adipocytes dissipate cellular energy as heat. Excessive nutrition or prolonged cold exposure suppress thermogenesis, but the mechanisms remain incompletely understood. Here we report that excessive cold or metabolic stress-induced proton leak into the matrix interface of mitochondrial innermembrane (IM) mobilizes 73 proteins from IM into matrix, which in turn alter mitochondrial bioenergetics. Interactome analysis indicates that key subunits of the electron transport chain and the mitochondrial calcium uniporter provide histidine-rich IM docking sites for 40 translocating proteins via pH-dependent protein-protein interactions. We further determine that 34% of translocating proteins correlate with obesity in human subcutaneous adipose tissue among which the top factor, acyl-CoA thioesterase 9 (ACOT9), enzymatically deactivates and prevents the utilization of acetyl-CoA in thermogenesis and promotes obesity. Overall, this study introduces stress-induced submitochondrial protein translocation as a new mitochondrial mechanism. One-Sentence SummaryMitochondrial stress regulates energy utilization by forcing translocation of IM-bound proteins into the matrix.

molecular biology↗

bioRxiv2020

Anti-tumor effects of an Id antagonist with no acquired resistance

Id proteins are helix-loop-helix (HLH) transcriptional regulators frequently overexpressed in cancer. Id proteins inhibit basic HLH transcription factors through protein-protein interactions, often inhibiting differentiation and sustaining proliferation. We recently identified a small-molecule, AGX51, which targets Id proteins for degradation and impairs ocular neovascularization in mouse models. Here we show that AGX51 treatment of cancer cell lines impaired cell growth and viability that results from a dramatic increase in ROS production upon Id degradation. In mouse models, AGX51 treatment suppressed breast cancer colonization in the lung, regressed the growth of paclitaxel-resistant breast tumors when combined with paclitaxel and reduced tumor burden in a model of sporadic colorectal neoplasia. Furthermore, in cells and mice, we failed to observe acquired resistance to AGX51 likely the result of the immutability of the binding pocket and efficient degradation of the Id proteins. Thus, AGX51 is a first-in-class compound that antagonizes Id proteins, shows strong anti-tumor effects and may be further developed for the management of multiple cancers.

cancer biology↗