(595e) Evaluation of Cytosolic and Mitochondrial NADPH Dynamics Reveals Their Relative Contribution to Growth Rates in Cancer Cells

NADPH, a highly compartmentalized electron donor in mammalian cells, plays essential roles in cell metabolism. However, less is known about how cytosolic and mitochondrial NADPH dynamics relate to cancer cell growth in response to nutrient challenges. To address this issue, we present NADPH composite index analysis, which can quantify the relationship between compartmentalized NADPH dynamics and growth rates by using genetically encoded NADPH sensors, an automated image analysis pipeline, and a correlation analysis. We find the distinct compartmentalized NADPH dynamics across cancer cell lines in response to varying nutrient conditions. Specifically, withdrawal of glucose generally lowered compartmentalized NADPH dynamics, with notable effects observed following glutamine and serine deprivation. Next, introducing a fractional contribution parameter (F), we calculated the relative contribution of compartmentalize NADPH dynamics to growth rates across cancer cell lines, and selectively inhibited their growths by perturbing cytosolic or mitochondrial NADPH metabolism. Mechanistically, we identified SLC25A1 as a key mitochondrial transporter required to maintain compartmentalized NADPH dynamics and cell growths. Altogether, our findings elucidate the link between compartmentalized NADPH dynamics and cancer cell growth, highlighting a potential of targeting compartmentalized NADPH metabolism for selective cancer cell growth inhibitions.