Metabolic Gatekeeping of Dormancy in Disseminated NSCLC Subpopulations

Numerous studies show that it is not individual cells but rather collective packs of invasive cells that metastasize. These collective invasion packs are observed histologically in patient tumors, mouse models, and 3D cultures. In many cases, a hierarchical group of leader and follower cells is observed, where the invasive leader cell at the tip of the invading pack guides the followers forward. Despite their prevalence, research generally focuses on how individual cells invade or studies treat cells as a homogenous group, thereby lacking the resolution to investigate subpopulations. Using an image-guided genomics approach we developed, we published that collective invading non-small cell lung cancer (NSCLC) subpopulations have differential genetic mutations and epigenetic profiles that support distinct metabolisms. Our preliminary data show that, while leader cells alone metastasize, these disseminated leaders primarily form non-proliferative micrometastatic lesions positive for markers of endoplasmic reticulum (ER) stress and cell cycle inhibition, suggestive of a dormancy phenotype. However, the mixing of leaders and followers within the primary tumor results in actively proliferating macrometastatic lesions. This raises the possibility that cell:cell cooperation between disseminated subpopulations is required to transition from micro- to macrometastatic disease. Our in vitro studies suggest a mechanistic link between oxygen tension, glycolysis, ER stress and ER-associated protein degradation (ERAD) in regulating this leader cell quiescence. We found that the glycolytic enzyme glucose 6-phosphate isomerase (GPI), which catalyzes the interconversion of glucose 6-phosphate and fructose 6-phosphate, is secreted in an oxygen (O2)-dependent manner, lowly expressed in highly invasive leader cells, and can rescue low oxygen induced stress in leaders. Based upon these data, we will test the overarching hypothesis that a GPI cargo exchange gatekeeps metabolic flexibility and ERAD-dependent disseminated leader cell dormancy to perpetuate tumor cell growth and promote tumor progression. We propose to define how a metastatic, dormant subpopulation of invasive cells relies on inter-subpopulation cooperation to activate and proliferate at the metastatic site, probe a model that positions GPI centrally within a metastatic dormancy axis, and deconstruct a new O2-dependent glycolytic secretory pathway that modulates ER-associated stress. These studies will have significant impact on resolving the fundamental mechanisms at the intersection of metabolic heterogeneity and cell:cell communication in collective invasion and metastasis. Project Number: 1R01CA299279-01A1 | Fiscal Year: 2026 | NIH Institute/Center: National Cancer Institute (NCI) | Principal Investigator: Adam Marcus (+1 co-PI) | Institution: EMORY UNIVERSITY, ATLANTA, GA | Award Amount: $572,378 | Activity Code: R01 | Study Section: Tumor Evolution, Heterogeneity and Metastasis Study Section[TEHM] View on NIH RePORTER: https://reporter.nih.gov/project-details/11292168