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Man-Made Molecule May Thwart Brain Cancer
September 24, 2002
By Keith Mulvihill
Scientists are hoping that an engineered molecule that homes in on brain tumor cells could one day be used to treat patients with glioblastoma, a deadly and difficult to treat form of brain cancer that accounts for about 40% of all primary brain tumors.
But before human trials can take place, the team of researchers must conduct further experiments to determine whether the drug has any harmful side effects.
Dr. Walter A. Hall of the University of Minnesota in Minneapolis presented his team´s findings Monday at the 52nd annual meeting of the Congress of Neurological Surgeons in Philadelphia, Pennsylvania.
Hall told attendees that the molecule, nicknamed DTAT, is made up of three parts. One part seeks out and zeros in on glioblastoma cells and "actually sticks itself to the cell." The second, or middle part, of DTAT helps the molecule penetrate the cell, and the third part, the poison, is made up of diphtheria toxin.
Diphtheria is caused by bacteria that primarily attack the larynx, tonsils and throat. The toxin produced by the bug can damage the nerves and heart. When used in DTAT, the protein interferes with the tumor´s ability to form new blood vessels.
In the investigation, Hall and colleagues took human tumor cells, implanted them into the brains of mice and let them grow for 2 weeks. Then they treated the mice with an injection of DTAT directly into the tumor every other day for 6 days.
"All of the treated mice had a greater than 90% reduction in tumor size, and followed over time, 60% had a complete and permanent cure," Hall told attendees.
The next step, Hall explained in an interview with Reuters Health, is for the team to determine whether or not the drug is toxic to humans. To do that, the researchers plan to conduct more studies in mice and monkeys.
If those experiments pan out, Hall says his team will seek permission from the US Food and Drug Administration to test the new drug in glioblastoma patients.
(Reuters Health)