Little squirt fights cancer

The seasquirt Diazona angulata anchors itself to rocks in the Philippines and manufactures a toxin called diazonamide A to ward off predators. That toxin just happens to kill cancer cells. Now, researchers at the University of Texas Southwestern Medical Center have modeled a new drug on this toxin that also kills cancer cells. Unlike its natural counterpart it does not harm healthy cells, which could make it a more useful drug. Team leader Patrick Harran says this molecule has a unique mode of action and is "teaching us more than we imagined". The structure of diazonamide A was first reported in 1991, but in 2001, Harran's team showed the initial assignment to be wrong and published the correct structure. He and his colleagues found that the toxin interacts with the cellular metabolic enzyme OAT, which was known to be involved in cellular metabolism but had no previously known role in cell division. However, it does not simply inhibit this enzyme but instead revealed that the enzyme has a second role, in cell division; hence the anticancer activity.