Endothelial calcium firing mediates extravasation of metastatic tumor cells

Metastatic dissemination is driven by genetical, biochemical and biophysical cues that favor the distant colonization of organs and the formation of life-threatening secondary tumors. We have demonstrated that endothelial cells (ECs) actively remodel during extravasation by enwrapping arrested tumor cells (TCs) and extrude them from the vascular lumen while maintaining perfusion. In this work, we dissect the cellular and molecular mechanisms driving endothelial remodeling. Using high-resolution intravital imaging in zebrafish embryos, we demonstrate that the actomyosin network of ECs controls tissue remodeling and subsequent TC extravasation. Furthermore, we uncovered that this cytoskeletal remodeling is driven by altered endothelial-calcium (Ca ²⁺ ) signaling caused by arrested TCs. Accordingly, we demonstrated that inhibition of voltage-dependent calcium L-type channels impairs extravasation. Lastly, we identified P2X4, TRP, and Piezo1 mechano-gated Ca ²⁺ channels as key mediators of the process. These results further highlight the central role of endothelial remodeling during extravasation of TCs and open avenues for successful therapeutic targeting.