Abstract 4842: Stress-induced Mitochondrial Adaptations in the Polyaneuploid Cancer Cell State

Metastatic cancer is responsible for 90% of cancer deaths and is incurable due to resistance to all systemic anticancer therapies. While the classic model of therapy resistance is described by the presence of pre-existing resistant clones from tumor cell heterogeneity, our lab proposes the polyaneuploid cancer cell (PACC) state as a survival mechanism that cancer cells access when exposed to environmental stress such as hypoxia and chemotherapy. Our preliminary data has shown that cells that enter the PACC state exhibit repeated whole genome doubling, an increase in cell size, and proliferative arrest. In addition, we observed that a subpopulation of PACCs can give rise to non-polyploid, proliferative progeny after release from chemotherapy, modeling cancer recurrence. We hypothesize that the PACC state drives therapeutic resistance and elimination of this adaptive state is key in tackling the incurability of cancer. Mitochondria are essential organelles that have multifaceted roles in the cellular stress response and drug resistance. They integrate metabolic pathways for ATP generation and macromolecule biosynthesis, regulate apoptotic cell death, and activate stress response mechanisms in presence of drug treatment. We found that cells in the PACC state increase mitochondrial biogenesis and live cell imaging with MitoTraker dyes indicate that they also have higher activity per mitochondria when compared to parental cells. Cells that accessed the PACC state also had higher levels of TCA cycle metabolites including citrate, isocitrate, alpha-ketoglutarate, succinate, fumarate, and malate, suggesting increased mitochondrial function. Future work includes analysis of mitochondrial morphology via live cell confocal microscopy and of mitochondrial function via metabolic flux analysis on glucose and glutamine metabolism of cells in the PACC state. Our eventual goal is to characterize how cells in the PACC state alter their mitochondrial structure and function to survive therapy. Identifying vulnerabilities of the PACC phenotype will enable new therapeutic approaches to overcome therapy resistance in cancer. Citation Format: Melvin Li, Laurie G. Kostecka, Sarah R. Amend, Kenneth J. Pienta. Stress-induced mitochondrial adaptations in the polyaneuploid cancer cell state. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4842.