Matrix composition and glucose availability cooperatively determine cancer spheroid bioenergetics in 3D hydrogels

The interplay between extracellular matrix (ECM) biophysical properties and nutrient availability is crucial in cancer metabolism, but the specific influence of different ECM components remains unclear. This study investigates how collagen and fibrin 3D hydrogels, with varying stiffness, alongside different glucose concentrations, differentially regulate the metabolic phenotype of A549 lung and Panc1 pancreatic cancer spheroids. We observed that while glucose availability predominantly dictates metabolic profiles in collagen-based matrices, particularly influencing A549 cell behavior, metabolic adaptation in fibrin hydrogels was co-regulated by matrix properties and glucose levels. Notably, lung cancer cells shifted towards glycolysis under high glucose in collagen, whereas pancreatic cancer cells, inherently more glycolytic, exhibited metabolic rigidity, especially under low glucose, irrespective of collagen stiffness. Conversely, fibrin matrices generally induced a less noticeable, more quiescent metabolic state in both cancer cells, particularly under glucose deprivation. Specifically, higher collagen concentrations tended to support anaerobic metabolism, especially under glucose scarcity. The findings of this study reveal a hierarchical interplay where ECM composition tunes the sensitivity of cancer cells to nutrient availability, underscoring the necessity of integrating both matrix-specific mechanical cues and nutrient gradients in advanced 3D tumor models for identifying context-dependent metabolic vulnerabilities. This could have potential implications for designing future effective therapeutic strategies targeting the tumor microenvironment.