Alterations to cancer drug allow it past the blood-brain barrier


Researchers at Johns Hopkins have changed the structure of a new cancer drug to allow it to more easily pass the blood-brain barrier, giving it access to target brain cancers in more effective doses.

An experimental cancer drug, 6 diazo-5-oxo L norleucine, also known as DON, was cultivated from bacteria found in soil in Peru 70 years ago, according to a release. The drug blocks protein-building mechanisms in charge of glutamine, but it is massively toxic and causes damage to the gastrointestinal system.

By enabling it to cross into the brain, scientists have limited the exposure of the drug to the rest of the body. To do this, they made DON more lipid soluble, giving it better access to the brain. In animal tests, the scientists used DON and the lipid-soluble derivative called 5c. After 30 minutes, the monkey with only DON had lost seven times that concentration in its blood than the one that received 5c. In the monkey that received 5c, it had 10 times the concentration in its cerebrospinal fluid, indicating the compound had crossed the blood-brain barrier.

“We showed that we can modify these drugs to have further specificity to target the brain and limit toxicity to the rest of the body,” lead researcher Barbara Slusher said. “This strategy can potentially be used to develop tailored drugs for different cancers.”