N-glycolylneuraminic acid as a carbohydrate cancer biomarker

One of the forms of aberrant glycosylation in human tumors is the expression of N-glycolylneuraminic acid (Neu5Gc). The only known enzyme to biosynthesize Neu5Gc in mammals, cytidine-5 '-monophosphate-N-acetylneuraminic acid (CMAH), appears to be genetically inactivated in humans. Regardless, low levels of Neu5Gc have been detected in healthy humans. Therefore, it is proposed that the presence of Neu5Gc in humans is from dietary acquisition, such as red meat. Notably, detection of elevated Neu5Gc levels has been repeatedly found in cancer tissues, cells and serum samples, thereby Neu5Gc-containing antigens may be exploited as a class of cancer biomarkers. Here we review the findings to date on using Neu5Gc-containing tumor glycoconjugates as a class of cancer biomarkers for cancer detection, surveillance, prognosis and therapeutic targets. We review the evidence that supports an emerging hypothesis of de novo Neu5Gc biosynthesis in human cancer cells as a source of Neu5Gc in human tumors, generated under certain metabolic conditions.

Automated summary

One form of abnormal glycosylation in human tumors is the expression of Neu5Gc, a type of acid. The enzyme responsible for producing Neu5Gc in mammals is believed to be inactive in humans. However, low levels of Neu5Gc have been found in healthy humans, indicating its acquisition from diet, such as red meat. Elevated levels of Neu5Gc have been consistently detected in cancer tissues, cells, and serum samples, suggesting its potential as a biomarker for cancer. This review examines the use of Neu5Gc-containing tumor glycoconjugates as cancer biomarkers for detection, monitoring, prognosis, and therapeutic targets.