Interplay between Matrix Viscoelasticity and Integrin Engagement Modulates Cancer‐Associated Fibroblast States

With the recent advent of single-cell transcriptomics, it is increasingly evident that cancer-associated fibroblasts (CAFs) are heterogeneous and exist as different subsets. These distinct CAF subsets likely harbor unique functions, most of which have not been fully elucidated. Efforts to understand CAF subset function and develop therapeutic strategies are currently hampered by the lack of robust preclinical models that controllably recapitulate CAF heterogeneity in vitro. Previous studies have suggested that CAF plasticity can be controlled through modulation of culture matrix parameters. In this study, it is hypothesized that hydrogel viscoelasticity and integrin engagement would influence the plasticity of encapsulated CAFs, specifically skewing CAFs to adopt either the myofibroblastic CAF (myCAF) or inflammatory CAF (iCAF) state. Using alginate hydrogels, it is found that patient-derived CAFs exhibit different morphologies and transcriptomic profiles reminiscent of the myCAF or iCAF subsets, depending on hydrogel viscoelasticity and cell adhesion. Furthermore, it is shown that the JAK/STAT signaling pathway is important for iCAF maintenance and could be leveraged to alter CAF states. Taken together, how matrix viscoelasticity coupled with integrin engagement modulates CAF states in vitro is demonstrated for the first time. The developed CAF models may be highly useful for understanding CAF function and to develop CAF-targeted therapies.