A high-fiber diet has long been considered beneficial in staving off colon cancer. Now, researchers at Medical College of Georgia have found that roughage keeps the disease at bay by activating a receptor with cancer killing potential.
The GPR109A receptor is activated by butyrate, a metabolite produced by fiber-eating bacteria in the colon.
The receptor puts a double-whammy on cancer by sending signals that trigger cell death, or apoptosis, and shutting down a protein that causes inflammation, a precursor to cancer.
"We know the receptor is silenced in cancer but it's not like the gene goes away," said Dr. Vadivel Ganapathy, co-author and chair of the Department of Biochemistry and Molecular Biology in the MCG School of Medicine.
Cancer shuts down the receptor by chemically modifying its gene through a process called DNA methylation.
It's a typical for cancer to turn genes off to suit its purpose, which is why DNA methylation inhibitors already are under study for a variety of cancers.
However, cancer patients likely also need something to ensure the receptor gets activated by butyrate, such as eating more roughage or, more likely, getting mega doses of butyrate or a compound with similar properties, Dr. Ganapathy said.
One of those activators, niacin, a B-complex vitamin, led to his discovery of the relationship between butyrate and GPR109A.
The study has been reported in the April issue of Cancer Research.