The antigen detected for breast cancer in the current paper arises from dietary Neu5Gc incorporation into the cancer marker Sialyl-Tn. It is the first example of a biomarker in the form of human "xeno-autoantibodies" to a dietary molecule. The team discovered that anti-Neu5Gc antibodies could be key to predicting cancer risk, for diagnosing cancer cases early and in high concentration, used as a treatment for suppressing tumor growth. They sampled 385 human blood samples and discovered that patients with carcinomas have elevated levels of antibodies to one specific Neu5Gc-containing sugar chain that incorporates into the cancer marker Sialyl-Tn. The scientists then found that introducing purified human anti-Neu5Gc antibodies may have immunotherapeutic potential: they specifically kill Neu5Gc-expressing mouse or human tumors when applied at higher concentrations.

"Precisely how therapeutic antibodies work in patients remains unclear, even in therapies already approved by the Food and Drug Administration," said Richard Schwab, MD, who co-led the overall research study. "It is likely a combination of signaling immune cells to kill cancer cells and antibodies directly killing cells by recruiting other proteins in the body. Understanding how lower levels of antibodies stimulate cancer growth while strong responses can kill cancer cells will be critical to moving this approach safely into cancer treatment."

The study was done by leading researchers in the field and led by Richard Schwab, MD, Assistant Professor of Medicine, and Ajit Varki, MD, Professor of Medicine and Cellular and Molecular Medicine, with other faculty at the UC San Diego Moores Cancer Center and the UCSD Glycobiology Research and Training Center. Collaborators include researchers from the groups of Xi Chen at UC Davis, Inder Verma at the Salk Institute and scientists from Sialix, Inc. Sialix maintains the exclusive rights to the commercialization of the biomarker and therapeutic applications of the research.

Source: Sialix Inc.