Metastatic Tumor Cells Exploit Their Adhesion Repertoire to Counteract Shear Forces during Intravascular Arrest

Abstract

Summary: Cancer metastasis is a process whereby a primary tumor spreads to distant organs. We have demonstrated previously that blood flow controls the intravascular arrest of circulating tumor cells (CTCs) through stable adhesion to endothelial cells. We now aim to define the contribution of cell adhesion potential and identify adhesion receptors at play. Early arrest is mediated by the formation of weak adhesion, depending on CD44 and integrin αvβ3. Stabilization of this arrest uses integrin α5β1-dependent adhesions with higher adhesion strength, which allows CTCs to stop in vascular regions with lower shear forces. Moreover, blood flow favors luminal deposition of fibronectin on endothelial cells, an integrin α5β1 ligand. Finally, we show that only receptors involved in stable adhesion are required for subsequent extravasation and metastasis. In conclusion, we identified the molecular partners that are sequentially exploited by CTCs to arrest and extravasate in vascular regions with permissive flow regimes. : Osmani et al. demonstrate that CTC metastatic potential scales with adhesion ability. CTC intravascular arrest is controlled by a tug of war between flow forces and adhesion receptor binding energies. Low-binding-energy receptors mediate initial transient arrest, whereas high-energy receptors stabilize bonds and facilitate extravasation and colonization. Keywords: circulating tumor cell, arrest, adhesion, metastasis, biomechanics, zebrafish, integrins