Platelet-Tumour Cell Interactions

Publisher Summary This chapter describes platelet interactions with tumor cells both in vitro and in vivo . Tumor cells show a selective organ preference to establish metastases. The adhesion of tumor cells to the vessel wall is stimulated by membrane antigens present on activated platelets. Platelets and leucocytes mediate the adhesion of tumor cells to the endothelium and to the extracellular matrix through the activation of specific adhesive receptors and the release of cytokines and chemokines. Platelet activation—with subthreshold doses of thrombin or other agents released by cancer cells—stimulate tumor cell adhesion to the vessel wall, with a mechanism involving activation of selectins, integrins, imunoglobulin G-like molecules, and other adhesive receptors. Similar receptors present on neutrophils, monocytes, and endothelial cells take part to this process, with a concerted action. Growth factors, cytokines, chemokines, and other products released after platelet aggregation and activation stimulate the adhesion of tumor cells to activated endothelium.