'Squirting sea doughnut' could lead to new cancer therapies

In collaboration with the Press Association

A chemical found in a tiny doughnut-shaped sea squirt attacks cancer cells in a completely new way, while leaving normal cells unharmed, according to a preliminary US study.

Finding out precisely why the chemical affects only cancer cell division will give researchers deeper insights into this crucial process.

It could also lead to new treatments based on the chemical, known as diazonamide A.

Diazonamide A's ability to attack cancer cells was discovered in 1991, but difficulties reproducing and manufacturing it in the laboratory have hampered research.

But these problems have recently been overcome, and researchers have now discovered that the toxin works by targeting a cell's scaffolding, made out of a protein called tubulin.

The tubulin scaffolding is essential during cell division - a process critical to the growth and spread of cancer.

Several currently used cancer drugs attack the tubulin scaffold directly, but can cause side-effects such as nerve and bone marrow damage.

Rather than attack tubulin directly, diazonamide A prevents division by interfering with a protein known as OAT, which was not previously known to be involved in cell division.

Crucially, it seems that OAT is not involved in cell division in normal cells, only in cancer cells. This makes the protein an ideal target for new drugs.

"This is a truly exciting result," said Dr John Schwab of the US National Institute of Health, which part-funded the study.

"Not only has this team identified a potent anti-cancer drug, but its unique mode of action avoids the kinds of side effects that make cancer chemotherapy so difficult."

The study was conducted by the University of Texas and is published in the Proceedings of the National Academy of Sciences.