ABSTRACT
One of the hallmark features of cancer is the abnormal level of glycosylations found on the cell surface. Whether abundantly-expressed, reduced or aberrantly-branched compared with those found on their normal counterparts, cancer cell surface glycans often correlate with type or stage of malignant progression. A cancer cell glycophenotype is dictated by its glycomic gene expression profi le consisting of glycosyltransferases, glycosidases, nucleotide-sugar transporters, sulfotransferases and glycan-bearing proteins or lipid. These glycomic factors collaborate in forming cancer-associated glycans and are widelyviewed as causal factors in a cancer cell’s virulent behavior. In this chapter, the novel roles of serine/ threonine (O)-glycan-modifying α2,6 sialyltransferases controlling lectin-binding interactions and related malignant and metastatic behaviors are reviewed. Recent studies showing that O-glycan modifi cations by N-acetylgalactosamine:α2,6 sialyltransferases (ST6GalNAc) impact intrinsic malignant potential in a host galectin (Gal)-1-and Gal-3-dependent manner will be highlighted. Related context on the history of cancer-associated glycan discovery and the prospect of glycomic factors as anti-cancer therapeutic targets will also be discussed to provide perspective for these novel fi ndings. In all, the importance and more recognizable roles of Gal-binding cancer cell O-glycans continue to provide new paradigms for cancer research and development of novel cancer therapies.
