Abstract

Significance Tumor growth intrinsically generates pressure onto the surrounding tissues, which conversely compress the tumor. These mechanical forces have been suggested to contribute to tumor growth regulation. We developed a microfluidic technique to produce 3D cell-based assays and to interrogate the interplay between tumor growth and mechanics in vitro. Multicellular spheroids are grown in permeable elastic capsules. Capsule deformation provides a direct measure of the exerted pressure. By simultaneously imaging the spheroid by confocal microscopy, we show that confinement induces a drastic cellular reorganization, including increased motility of peripheral cells. We propose that compressive stress has a beneficial impact on slowing down tumor evolution but may have a detrimental effect by triggering cell invasion and metastasis.