Microfluidic Mapping of Cancer Cell–Protein Binding Interaction

The interaction between tumor cells and microenvironment during metastasis is mediated by the binding of cell surface receptors, such as integrins and selectins, with protein ligands. Delineation of their binding interaction and identification of key receptors may be particularly important both in understanding extracellular matrix (ECM) remodeling and in developing potential therapeutic targets. Here we present a microfluidic chip that allows qualitative and quantitative mapping of a large population cell-protein interactions. It was found that β1 integrin showed stronger binding interaction with collagen than with other ECM proteins. The upregulated β1 integrin in invasive cancer cells enhanced cell-ECM interaction and may promote ECM remodeling. Cancer cells also showed strong interaction with plasma fibrinogen, the elevated level of which may help cancer cells arrest on blood vessels. We also verified that the chip may provide a platform for drug discovery by targeting integrins and cytoskeletons.