Sialic acid binding receptors—impressive targets for tumor treatment

Glycosylation abnormalities are common in all stages of tumor development, and sialic acid (SA) modified polysaccharides have been found highly expressed on many different types of tumor cells. These highly sialylated tumor cells promote the formation of tumor immunosuppressive environment and help tumor cells gain metastatic potential by interacting with SA binding receptors Siglecs/selectins expressed on peripheral immune cells or endothelial cells. Related theoretical studies have promoted the development of tumor therapeutic strategies by targeting SA-binding receptors, mainly including specific antibodies trastuzumab (Mylotarg) or polysaccharides that block the interaction between Siglecs/selectins and its ligands, as well as nano-based drug delivery systems modified with SA and its derivatives. This article reviews the specific mechanisms of how SA-binding receptor Siglecs/selectins-mediated interactions contribute to tumor development and metastasis, and tumor therapeutic strategies by targeting SA-binding receptors, as well as makes a rational evaluation and reflection on these therapeutic strategies.