Search

Sialic acid (SA), as the ultimate epitope of polysaccharides, can act as a cap at the end of polysaccharide chains to prevent their overextension. Sialylation is the enzymatic process of transferring SA residues onto polysaccharides and is catalyzed by a group of enzymes known as sialyltransferases (SiaTs). It is noteworthy that the sialylation level of glycoproteins is significantly altered when digestive cancer occurs. And this alteration exhibits a close correlation with the progression of these cancers. In this review, from the perspective of altered SiaTs expression levels and changed glycoprotein sialylation patterns, we summarize the pathogenesis of gastric cancer (GC), colorectal cancer (CRC), pancreatic ductal adenocarcinoma (PDAC), and hepatocellular carcinoma (HCC). Furthermore, we propose potential early diagnostic biomarkers and prognostic indicators for different digestive cancers. Finally, we summarize the therapeutic value of sialylation in digestive system cancers. [Display omitted] • Sialylation level significantly altered during the oncogenesis of digestive cancers. • Structures of sialylated glycoproteins and interactions between SiaTs are complex. • Altered sialylation levels can be detected in sera, paving the way for diagnosis. • Reducing the burden of SAs weakens the function of sialylation in tumor cells. • The diagnostic and therapeutic value of sialylation need clinical trials to verify. [ABSTRACT FROM AUTHOR]