A Devil of a Problem
Tasmanian Devils aren’t only a creature of cartoons. They’re an endangered marsupial found in the wild only in Tasmania (of course they are). And they’re disappearing really fast because of cancers that they are spreading to one another.
Their name is about right. Their disposition isn’t exactly laid back and calm. They sometimes bite each other, and ask questions later. In that process, they spread disease – deadly cancers which create facial tumors.
Cambridge University scientists found drugs targeting receptors in people with cancers could stop cancer in devils under laboratory conditions.
Two transmissible strains of the disease, which cause disfiguring facial tumors, have spread among the marsupials and led to a significant decline in population.
One strain, which was first noted in one animal in 1996, has spread throughout the “Tassie devil” population, while a second strain – first documented in 2014, appears to be confined to Devils living on the south east side of the island.
However, while both cancer strains are biologically different, visibly they are similar and are thought to be passed between Devils when they bite each other. Scientists have asked the Devils to “play nice” but that strategy hasn’t worked. When Tasmanian Devils fight, they bite one another, especially in the face.
The researchers, led by Dr Elizabeth Murchison, from the Department of Veterinary Medicine at Cambridge University found molecules known as receptor tyrosine kinases (RTKs) played an important role in sustaining the growth and survival of both the cancers.
However, drugs targeting RTKs – developed for human cancer – were found to efficiently stop the growth of devil cancer cells in a lab setting.
According to the study published in the journal Cancer Cell, “The two cancers have similar patterns of mutation show no evidence of exposure to exogenous mutagens or viruses. Genes encoding PDGF receptors have copy number gains and are present on extrachromosomal double minutes. Drug screening indicates causative roles for receptor tyrosine kinases and sensitivity to inhibitors of DNA repair. Y chromosome loss from a male clone infecting a female host suggests immunoediting. These results imply that Tasmanian devils may have inherent susceptibility to transmissible cancers and present a suite of therapeutic compounds for use in conservation.”
In other words drugs use to fight cancer in people may help. Now, the question is how to get to the animals before they become too ill. Meanwhile their genetic viability is narrowing as they become more endangered.