Cells that protect nerves are the origin of transmissible cancers devastating wild Tasmanian devils.
Scientists find the gene expression fingerprint of the Devil Facial Tumour Disease (DFTD) that has caused such widespread devastation in Tasmanian Devil populations and could lead to their extinction. Gene expression fingerprints identify all the genes switched ‘on’ in a cell – effectively a picture of all the activity in a cell at one time.
An international research effort led by Australian scientists and involving our bioinformatics researchers pinpoints tumours originated in Schwann cells, which insulate and protect peripheral nerve fibres. It also leads to the first even diagnostic test for the disease, using a genetic marker of the disease. The team includes Dr Tony Papenfuss from the Walter and Eliza Hall Institute, Dr Liz Murchison from the Australian National University and Associate Professor Greg Woods from the University of Tasmania's Menzies Research Institute.
A devastating disease
Devil Facial Tumour Disease is a transmissible cancer that affects only Tasmanian devils and was first reported in 1996. It is spread by biting and quickly kills the animals. The disease is characterised by large tumours, mostly on the face and mouth, and is always fatal. The team took biopsies from devil tumours and extracted their RNA to investigate gene expression markers for the disease. Papenfuss, a bioinformatics researcher, says the team determined which genes were switched on in the facial tumours and identified their gene expression signature.
"When we compared the signature of the tumours to other normal tissues we found the tumours were most like Schwann cells," Papenfuss says. The team also determines that the disease began in ‘patient zero’ in Tasmania – a single devil that developed a tumour in Schwann cells. “Our study also showed that devil tumours were more similar to each other than to their hosts. We were able to identify this by using the largest dataset of genetic markers to date.
“This proved that the tumours were clonal, and derived from a single devil.”
In the long-term, the researchers hope that, with continued support, they may be able to use this information to prevent or treat Devil Facial Tumour Disease. The research was conducted as part of the Save the Tasmanian Devil Program's efforts to further explore DFTD.