British scientists said Thursday that tadpoles could provide the key to developing anti-skin cancer drugs and a compound that blocked the development of the distinctive markings of tadpoles in experiments could help in preventing melanoma.

The researchers at the University of East Anglia (UEA) claim to have found a compound that blocked the movement of potential cancer causing pigment cells in tadpoles and humans that cause melanoma. This is caused by the uncontrolled movement and growth of pigment cells called melanophore, in both tadpoles as well as humans.

Melanoma is a difficult to treat cancer particularly in patients with advanced stages. The treatments that are currently used are limited in there impact. Researchers said that by blocking the migration it was possible to prevent the development and spread of cancerous tumors.

Dr Grant Wheeler, from UEA's School of Biological Sciences, who led the study said, "Once the cells migrate to other parts of the body and form secondary tumours, melanoma is difficult to treat by surgery or chemotherapy and often leads to death."

The study was undertaken by the UEA in partnership with the John Innes Centre (JIC) and Pfizer. The joint study used the South African clawed frog tadpoles also known as Xenopus Laevis, as they have the same organs, molecules, and physiology as humans, which means that the same factors result in cancer forming in both Xenopus tadpoles and humans.

The researchers examined 2,000 compounds listed by the U. S. National Cancer Institute to try to narrow it down to one that might potentially block pigment cell movement. They felt the most likely was a metalloproteinase inhibitor known as NSC 84093 which they dissolved in water and then allowed fertilized frog eggs to grow in it.

As the embryos turned into tadpoles the movement of the pigment cells stopped and this resulted in the tadpoles not developing their characteristic markings. Wheeler said, "This is 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."

The findings are published in the Cell Press journal Chemistry and Biology and give hope that the drug could one day stop the mutant melanocytes that cause skin cancer from spreading in the body. "We hope to get a potential therapy for humans in the future, but this is still early days," Wheeler said.

Ed Yong, health information manager at Cancer Research UK said, "There is still a lot of work to do before these interesting but preliminary results can be used to benefit people affected by cancer. But it just goes to show that studying animals like tadpoles, which may seem unusual, could lead to potential cancer drugs in the future."