Garrow believes BHMT inhibitors may work best in concert with other drugs. "In today's medicine, there's rarely one magic-bullet drug. We know that when you decrease the availability of methionine to cancer cells, another cancer drug called cisplatin works better. So a drug that inhibits BHMT, which decreases methionine availability, may well enhance the efficacy of another cancer treatment drug," he said.
Elevated levels of homocysteine could be a negative side effect of such therapy, but Garrow said the benefits of the drug would likely outweigh the risk. "A cancer patient would probably take the BMHT inhibitor for a limited time, while vascular disease--associated with high homocysteine levels--progresses over the course of a lifetime."
Garrow believes another therapeutic application for BHMT inhibitors could involve betaine, one of the enzyme's substrates.
"When you inhibit BHMT, you also block the utilization of betaine. Betaine not only donates a methyl group to homocysteine to form methionine, it also functions as an osmolyte, helping to regulate water content in the cells. We think the BHMT inhibitor could also be medically useful when there is unwanted diuresis or unwanted loss of water," he said.
Garrow's work with BHMT in mice was published in the June issue of the Journal of Nutrition. Co-authors include Michaela Collinsova, Jana Strakova, and Jiri Jiracek of the Academy of Sciences of the Czech Republic.