Beyond the proteolytic activity: Examining the functional relevance of the ancillary domains using tri-dimensional (3D) spheroid invasion assay

Abstract

In this chapter, we describe a straightforward protocol to generate multicellular tumor spheroids (MTSs) and evaluate the role of specific genes in regulating cell invasiveness in real-time and tridimensional (3D) matrices. This approach provides advantages over other conventional invasion assays by offering intimate cell–cell and cell–ECM contacts and by mimicking the pathophysiological characteristics observed in tumor microenvironments (e.g., microregional gradients in glucose and O2 concentrations and metabolic and proliferative tumor heterogeneity). We also provide an original and semiautomated approach to quantify MTS invasion using the freely available ImageJ software and plugins.