Current microphysiological systems (MPS) depend on the notion that cultured human cells cultured in flasks hold the same phenotypic and functional roles as the cells of the native tissue. Many MPS include some type of fibroblast, the cells that make up connective tissue. Fibroblasts are highly functional in constructing and maintaining the homeostasis of the extracellular matrix (ECM). This includes cancer associated fibroblasts (CAF), which interface with cancerous tumors. In vivo, CAF remodel the ECM to influence cell migration, invasion, and growth. However, what is not known is if their functional and phenotypic nature is matched in vitro. In order to create physiologically relevant tumor microenvironments, it is necessary to determine this. Here we aim to validate the profibrotic nature of human lung CAF especially as compared to normal human lung fibroblasts (HLF) in different types of culture including 2D, 3D, and sculpted 3D. MPS modelling tumors are implemented to test chemotherapeutic drugs and learn more about specific cancer-related pathways, and CAF are implemented with the belief that their role in native tissue will be reflected. In addition, we test CAF specific genes to further determine in vitro differences. No matter the complexity of a developed MPS, if the inputs are not physiologically relevant the outcomes will not be either. Results from this study will attempt to provide validation for in vitro models utilizing CAF thus allowing for more realistic MPS. Therefore, the validation of the profibrotic nature of CAF is critical to the nature of cancer research and drug development.
