Abstract A012: Extracellular glucose level regulates cell mechanics and invasion of triple-negative breast cancer cells

Abstract Cell mechanics, defined by deformability and contractility, play critical roles in cancer metastasis, yet the soluble cues and molecular pathways linking the tumor microenvironment to these mechanotypes remain poorly understood. Glucose availability varies widely between circulation, normal tissue, and tumor tissue, and cancer cells adapt through metabolic reprogramming that impacts growth, invasion, and epithelial–mesenchymal transition. Here, we investigate how glucose levels and glucose transport influence breast cancer cell mechanics and metastatic behavior, with a focus on triple-negative breast cancer (TNBC). Using high-throughput mechanotyping assays, we demonstrate that elevated extracellular glucose (>5 mM) decreases deformability and increases contractility of breast cancer cells in a concentration-dependent manner through F-actin rearrangement and non-muscle myosin II (NMII) activation. Mechanistically, this is driven by the cAMP–RhoA–ROCK–NMII signaling axis, while calcium and MLCK are dispensable. In TNBC, we further identify glucose transporter 3 (GLUT3) as a key mediator of this response: GLUT3 inhibition by the selective inhibitor G3iA reduces glucose uptake, glycolysis, and ATP production, leading to AMPK activation, suppressed myosin activity, and impaired invasion. GLUT3 inhibition also activates the cAMP–PKA–VASP pathway, reducing F-actin levels and stiffness as measured by Atomic Force Microscopy, and increases YAP phosphorylation with reduced transcriptional activity. These mechanical alterations diminish motility in vitro and lung metastasis in vivo. Together, our findings establish a mechanistic link between glucose metabolism, cellular mechanotypes, and metastatic progression in breast cancer, highlighting the potential of integrating glucose control and mechanotype-targeting strategies into therapeutic approaches, particularly for TNBC. Citation Format: Aadil Qadir Bhat, Seeun Oh, Jun-Yong Choe, Tae-Hyung Kim. Extracellular glucose level regulates cell mechanics and invasion of triple-negative breast cancer cells [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Cancer Evolution: The Dynamics of Progression and Persistence; 2025 Dec 4-6; Albuquerque, NM. Philadelphia (PA): AACR; Cancer Res 2025;85(23_Suppl):Abstract nr A012.