Carbohydrate Aids Mabs in Killing Cancer Cells

A natural carbohydrate recruits immune cells to assist monoclonal antibodies (Mabs) in killing cancer cells, according to research reported in the July 15, 2004, issue of The Journal of Immunology.

There are two other mechanisms by which Mabs can destroy tumors. One is to attract natural killer T cells to attack a tumor, and the other is to activate the complement system, a series of blood proteins that work together to puncture tumor cells. The new, third mechanism was discovered by researchers at the University of Louisville (KY, USA), working at the James Graham Brown Cancer Center.

This third mechanism relies on an orally administered yeast beta glucan called WGP Beta Glucan. This natural carbohydrate binds to specific receptors on neutrophils, which enable them to "see” the cancer as foreign. The antibodies and complement attract the primed neutrophils to the site of the cancer, where they join in the attack.

In the current study, 100% of mice with liver cancer treated with WGP Beta Glucan three days before the start of Mab therapy survived 100 days, compared to only 35 days for mice treated only with Mabs. The researchers also observed significant increases in tumor regression in mice treated with WGP Glucan in combination with Herceptin, a Mab developed to treat metastatic breast cancer.

"Our research over the past decade has firmly established the efficacy of beta glucan as an immune system enhancer and, more recently, as a highly promising complementary cancer immunotherapy,” noted Gordon Ross, Ph.D., lead researcher and director of the tumor immunobiology program at the cancer center. "The next steps will be to study the benefits of WGP Beta Glucan in combination with Mabs and cancer vaccines in humans.”

WGP Glucan is a patented compound of Biopolymer Engineering, Inc. (Eagan, MN, USA), which intends to develop the compound for pharmaceutical use. The compound is currently available as a dietary supplement. Although the researchers also studied the efficacy of other sources of beta glucan, such as barley-based beta glucan, they found that the yeast WGP Beta Glucan from Biopolymer Engineering produced significantly better results.

Although both oral beta glucan and intravenous beta glucan were shown to be effective, oral beta glucan requires the presence of complement on the surface of cancer cells. In tests where the tumors lacked complement, or the granulocytes lacked specific receptors (CR3) on the granulocytes, the beta glucan therapy failed.



Related Links:
Univ. of Louisville
Biopolymer Engineering