New devil cancer fears

TASMANIAN devil facial tumour disease 2 is becoming invisible to the animal’s immune system, a study released last week has found — meaning the cancer could spread more rapidly.

Since its discovery in 2014, DFT2 has been confined to devils in southern Tasmania but its prevalence is rising.

Study lead researcher, Hannah Siddle from the University of Southampton, said the protein MHC class 1 found on all devil cells acts as a barcode for the immune system.

The immune system scans it to find out whether the cell is healthy or infected, she said.

She said DFT1, which is believed to have emerged in the state’s North East more than 20 years ago, caused the loss of these protein cells, meaning the tumour was invisible to the devil immune system.

Her study shows this is starting to occur in the second facial cancer as well.

“Losing these genetic molecules would really take the constraints off this tumour,” Ms Siddle said.

Former government wildlife biologist Nick Mooney said he hoped the DFT2 research could give greater insight into the cancer.

Ms Siddle, who grew up in Sydney and lived in Hobart as a child, said her research was limited by the number of samples tested. The study analysed eight cancers from six devils.

She said samples from three devils had strong MHC class 1 expression, two had a weaker prevalence, and in one the protein could not be found at all.

“What we really need to do now is a bigger study,” she said. “To find out whether this is something that is becoming widespread.”

Ms Siddle said DFT1 had already diminished devil populations, and if a second tumour spread it could have an even more devastating effect. She said being prepared could help stop widespread transmission.

Ms Siddle, who completed a PhD in evolutionary genomics and genetics at the University of Sydney in 2009, said funding for her research was from British and European sources.

University of Tasmania Menzies Institute researcher Cesar Tovar Lopez said they contributed in a minor capacity to the paper and hoped to play a role in future studies.

It is believed both tumours are spread by biting.