Basement membrane invasion assays: native basement membrane and chemoinvasion assay.
To escape the primary tumor and infiltrate stromal compartments, invasive cancer cells must traverse the basement membrane (BM). To break this dense matrix, cells develop finger-like protrusions, called invadopodia, at their ventral surface. Invadopodia secrete proteases to degrade the BM, and then elongate which allows the cell to invade the subjacent tissue. Here, we describe two complementary invasion assays. The native BM invasion assay, based on BM isolated from rat or mouse mesentery, is a physiologically significant approach for studying the stages of BM crossing at the cellular level. The Matrigel-based chemoinvasion assay is a powerful technique for studying invadopodia's molecular composition and organization at the subcellular level.