Glycosylation is involved in malignant properties of cancer cells

Cancer cells express unique carbohydrate structures in glycoproteins and glycolipids, and their structures have been considered to be cancer-associated antigens. However, the involvement of their antigens in the malignant properties has not been well understood. The functional studies of glycosyltransferase genes revealed important regulatory roles of glycosylation in the malignant properties of cancer cells. In particular, we have characterized the molecular signaling pathways that are activated or inactivated by gangliosides in various cancer cells. Our results indicated that disialyl gangliosides GD3 and GD2 enhance malignant properties of human melanoma, osteosarcoma, and small cell lung cancer cells. However, monosialyl ganglioside GM1 attenuates these properties in melanoma and lung cancer cells. In addition to glycolipids, glycoproteins are also reported to be involved in regulating malignant properties and maintenance of cancer stem cells