N-glycan profiles as tools in diagnosis of hepatocellular carcinoma and prediction of healthy human ageing.

Protein glycosylation, the most common form of co-translational modification of proteins, is the enzymatic addition of sugars or oligosaccharides (glycans) to proteins. Protein glycosylation increases the diversity of the functions of proteins encoded in the genome. The result is that different glycomes of the same protein may have different functional, kinetic or physical properties. The glycosylation pathway is largely regulated by the condition of the cells, which means that the sugar chains can be altered by the physiological or pathophysiological condition of the cell. Thus, the type of glycans produced by cells, tissues, or organism could reflect their current physiological state. We determined the N-glycan profiles of serum proteins by using DNA sequencer-based carbohydrate analytical profiling technology. We show that two N-glycan structures (NGA2F and NA2F) present in human blood glycoproteins change with ageing, and that one triantennary glycan (NA3Fb) is correlated with tumor stage in HCC patients. Therefore, examining alterations in serum glycan fingerprint by using our platform could be a suitable tool for monitoring the healthiness of ageing and for the follow-up of pathophysiological conditions such as liver cancer.