Expanding the xenotopic toolbox for compartment-specific manipulation of redox stress in cancer

Metabolic remodeling is a hallmark of cancer cells. Understanding metabolic rewiring in different types of malignant cells can be leveraged therapeutically by targeting these metabolic vulnerabilities. However, the lack of tools to directly assess the impact and temporal aspects of major components of redox metabolism limits our understanding of its role in cancer development and/or progression. Additionally, this dearth of available tools hinders our ability to distinguish whether redox metabolism plays a causal role or is simply a bystander in most cancer cells, representing a key knowledge gap. Moreover, the lack of a methodology to systematically test the efficacy of promoting pro-reductive versus pro-oxidative shifts in metabolism prevents assessing the significance of these shifts in rewiring cancer biology. Targeting upstream, rate-limiting enzymes that regulate the redox state further complicates the interpretation of the significance of redox stress in cancer biology due to the high compartmentalization of redox coenzymes, the moonlighting activities of enzymes, the presence of multiple isoforms that alleviate the effects of single-enzyme perturbations, and, more importantly, the lack of physiological relevance when using cultured cells or xenograft models. One approach that avoids all these caveats is introducing xenotopic tools that directly alter the ratios of key redox coenzymes in a tissue- and organelle-specific manner. We and others have previously developed and validated several xenotopic tools in vivo that target various cancer-related metabolic pathways, including major redox coenzymes. Although some of these tools have been created as flox/flox models in mice, it is not feasible to test all of them in different cellular compartments or in all possible combinations in cancer, stromal, or immune cells in mice. To address this, we have created an efficient solution by developing a Drosophila model that allows us to monitor tumor growth and overall survival in a semi high-throughput manner. This proposal will further advance the creation and validation of organelle-specific versions of our tools and their systematic analysis in a Drosophila cancer model to test the hypothesis that redox stress represents a metabolic vulnerability of cancer cells that can be exploited therapeutically. Our approach constitutes a substantial methodological advancement as it will allow us to screen for multiple combinations of different redox states across various compartments and determine their significance in tumor growth in vivo. The proposed experiments will provide important mechanistic insights into the metabolic rewiring in cancer and a comprehensive inventory of compartmentalized redox pathways. Ultimately, this project will evaluate novel interventions that could target metabolic vulnerabilities in cancer cells and be employed as potential therapeutic strategies for the treatment of various cancers. Project Number: 1R21CA313483-01 | Fiscal Year: 2026 | NIH Institute/Center: National Cancer Institute (NCI) | Principal Investigator: Valentin Cracan (+1 co-PI) | Institution: SCINTILLON INSTITUTE FOR PHOTOBIOLOGY, SAN DIEGO, CA | Award Amount: $480,205 | Activity Code: R21 | Study Section: Special Emphasis Panel[ZRG1 BTC-T (80)] View on NIH RePORTER: https://reporter.nih.gov/project-details/11354493