In Vitro Study of Cancer Cell Extravasation in Microfluidic Platform

Cancer metastases arise from the cancer cells that disseminate from the primary tumor, intravasate into the vascular system and eventually transmigrate across the endothelium into to a secondary site through a process of extravasation. Microfluidic systems have a major advantage in studying cancer extravasation since they can mimic aspects of the 3D in vivo situation in a controlled environment while simultaneously providing in situ imaging capabilities for visualization, thereby enabling quantification of cell-cell and cell-matrix interactions. Moreover, microfluidics enable parametric study of multiple factors in controlled and repeatable conditions. This thesis describes novel 3D microfluidic models to mimic the tumor microenvironment and vasculature during cancer cell extravasation in order to investigate the critical steps of extravasation. First, a general non-organ-specific cancer cell extravasation model is developed in which the endothelial cells that cover the walls of the microfluidic channel represent the vessel endothelium, and the entire extravasation process including tumor cell adhesion to the endothelium and subsequent transmigration can be observed. A second model is then introduced to mimic organspecific extravasation and investigate the preference of certain types of cancer to target specific organs for metastass. The improved model was used to study the specificity of human breast cancer metastases to bone, by recreating a vascularized bone-mimicking microenvironment. The tri-culture system allowed us to study the transendothelial migration of highly metastatic breast cancer cells