Glycosylation is a ubiquitous cellular or microenvironment-specific post-translational modification that occurs on the surface of normal cells and tumor cells. Tumor cell-associated glycosylation is involved in hematogenous metastasis. A wide variety of tumors undergo aberrant glycosylation to interact with platelets. As platelets have many opportunities to engage circulating tumor cells, they represent an important avenue into understanding the role glycosylation plays in tumor metastasis. Platelet involvement in tumor metastasis is evidenced by observations that platelets protect tumor cells from damaging shear forces and immune system attack, aid metastasis through the endothelium at specific sites, and facilitate tumor survival and colonization. During platelet-tumor-cell interactions, many opportunities for glycan-ligand binding emerge. This review integrates the latest information about glycans, their ligands, and how they mediate platelet-tumor interactions. We also discuss adaptive changes that tumors undergo upon glycan-lectin binding and the impact glycans have on targeted therapeutic strategies for treating tumors in clinical settings.
Keywords: Cancer metastasis; glycoconjugations; glycosylation; lectin; platelets.
Tumor hematogenous metastasis is a serious threat to the survival and prognosis of patients, and a variety of factors help this process to occur, and platelets are also involved. During tumor cell metastasis, platelets can adhere to each other and tumor cells, a phenomenon that leads to the immunity of tumor cells from various threats in metastasis, including immune attacks, shearing forces, etc. Scientists have shown that the adhesion effect between platelets and tumor cells is often dependent on various types of sugars, which are not the sugars we ingest. These sugars often appear as glycosylation modifications on the proteins of the cells, including normal glycosylation modifications and some abnormal structures that only appear on tumor cells, and their ligands, lectins, are also present on the surface of the tumor cells or platelets. Their combination results in the better adaptation of tumor cells to the metastatic process, where proteins such as P-selectin, CLEC-2, and Galectins have been more studied. Focusing on Glycan-Lectin interactions between platelets and tumor cells, related studies help us to further understand tumor metastasis, and intervene in this binding and develop related drugs with great potential.