Scientists doing groundbreaking research in the UK have suggested tadpoles may hold the key to developing new drugs to treat skin cancer.

There is a study about it in the latest issue of the Cell Press journal Chemistry & Biology published on 30 January. It describes the work of lead investigator Dr Grant Wheeler of the University of East Anglia's School of Biological Sciences, and colleagues.

The project was started with funds from the UK Medical Research Council, and is a joint effort between the UEA and two partners: John Innes Centre (JIC) and Pfizer.

The frog species Xenopus Laevis (the South African clawed frog) is a distant cousin of humans. Although our ancestors diverged some 360 million years ago, this was not so long ago in evolutionary terms, so we still share very similar physiologies.

One example of how useful this similarity is was used right up to the 1960s, when the human pregnancy test relied on injecting a woman's urine sample into a live frog. If the frog laid eggs as a result, it meant the woman's urine contained the hormone hCG (human chrionic gonadotropin), indicating she was pregnant.

Another area of physiology that we share with the frogs is the development of cancer, including skin cancer.

Uncontrolled movement and proliferation of pigment cells or melanophores leads to a particularly dangerous skin cancer in both humans and Xenopus Laevis tadpoles. The pigment cells give the tadpoles their distinctive markings and help the skin develop the familiar green-brown colour of the adult frog.

The movement is regulated by a group of molecules called matrix metalloproteinases (MMPs).

In this study, Wheeler and colleagues tested a man-made MMP inhibitor, which they know as NSC 84093, and found it was effective at blocking the movement of pigment cells in the skin of the tadpoles.

Wheeler said that their discovery was:

"An exciting advance with implications in the fight against cancer."

"The next step is to test the compound in other species and, in the longer term, embark on the development of new drugs to fight skin cancer in humans," he explained.

"A Chemical Genomic Approach Identifies Matrix Metalloproteinases as Playing an Essential and Specific Role in Xenopus Melanophore Migration."
Matthew L. Tomlinson, Pingping Guan, Richard J. Morris, Mark D. Fidock, Martin Rejzek, Carla Garcia-Morales, Robert A. Field, Grant N. Wheeler.
Chemistry & Biology 30 January 2009 (Vol. 16, Issue 1, pp. 93-104).
Click here for the Article.

Sources: Journal Abstract, University of East Anglia.

: Catharine Paddock, PhD