Tumor cells thriving in a solid microenvironment are surrounded by stromal cells, some of which secrete components such as collagen and glycoproteins that constitute the extracellular matrix (ECM). This scaffolding provides more than just structural support to tumor cells. Indeed, the stromal compartment has been targeted for drug therapy given its reciprocal interplay with tumor cells. A predominant component of the stroma that plays a vital role in tumor progression is a group of mesenchymal cells called fibroblasts. Recent studies have revealed that fibroblasts found in a tumor microenvironment display different markers compared to naïve fibroblasts residing in normal tissues, thus the name cancer-associated fibroblasts (CAFs) to reflect their activation. In the current studies, we aim to evaluate the functional significance of CAFs in the vicinity of tumor cells. How do “tumor-educated” fibroblasts modulate the migratory behavior of tumor cells and vice versa? CAFs enhance tumor progression by also releasing angiogenic factors to trigger migration of endothelial cells into the tumor site and formation of new blood vessels, which results in tumor migration to distant organs. However, these angiogenic factors such as vascular endothelial growth factor (VEGF) can be sequestered by the ECM and require presence of metalloproteases (MMPs) that act as molecular scissors degrading the ECM components, thus liberating these angiogenic factors. Therefore, we will also evaluate whether activated CAFs secrete MMPs and mediate recruitment of endothelial cells. We will be employing different techniques, such as a comparative analysis of cells grown in conventional 2D cultures versus 3D spheroids, where the latter approach mimics a growing tumor in vivo. We will also use Boyden chambers migration assays to evaluate whether factors secreted by “tumor-educated” fibroblasts mediate the migration of tumor cells and vice versa.
