Study Reveals Cancer-Drug Resistance

U.S. researchers say they have discovered a mechanism by which cancer cells become resistant to a specific class of drugs.

Using the worm Caenorhabditis elegans, researchers at the University of Texas Southwestern Medical Center found a mutation in a single protein in the worm renders a potential new cancer drug ineffective.

The drug is a derivative of a compound called hemiasterlin. Because hemiasterlin compounds are being tested as a way to fight multi-drug resistance, the newly discovered resistance effect is problematic, the researchers said.

A major problem for cancer therapy is that if cancer cells can survive long enough, they have a chance to undergo mutations that make them resistant to anticancer drugs, said Dr. Michael Roth, professor of biochemistry and senior author of the study.

One way that cancer cells resist multiple drugs is through the action of the multi-drug resistance protein, which pumps most drugs out of the cell before they can have any effect. However, hemiasterlin bypasses that pump and kills cancer cells by preventing them from dividing.

The research is explained in the early online edition of the Proceedings of the National Academy of Sciences.