May 192014
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No, dear reader, it’s not like you think: JUnQ is not going to blame the devil for all cancer there is, since that alone just would not cure the disease. The title of this little piece is rather derived from the Australian island of Tasmania, where there lives a ~8 kg weighing carnivore called the Tasmanian devil. The devil may have gotten his name from the aggressive fighting behavior that they cultivate among themselves. But it is exactly this aggressive fighting that may drive the little devil into extinction: Excessive biting promotes the spread of a highly contagious tumor across the whole
devil population in Tasmania [1]. In a way the tumor is a kind of transplant, called allograft that originates from another donating devil. Invasion of cells from cells of alien organisms, even if they belong to the same species, should generate an immune response of the recipient, especially if the alien cells form a life threatening tumor. However, the so called devil facial tumor disease (DFTD) originates from Schwann cells, cells that generate the isolating myelin coating of neurons [2], is 100% mortal while generating no immune response at all.

Why the immune system of the devil cannot cope with the tumor and how that may be related to the tumor’s nerve cell origin could recently be addressed by Siddle and coworkers [4]. A normal immune response requires the processing of a biological marker of the pathogen into a minimal signature. This signature, called antigen, is then presented on the cell surface by so-called MHC proteins. Cells of the immune system are able to recognize antigens presented in this way, which subsequently launches an immune response. Siddle and coworkers could show, that the antigen procession pathway, which is prerequisite for any immune response, is down regulated in DFTD tumor cells. Since the immune evasion of the tumor cells is caused by a difference in regulation and not by a mutation, meaning by a loss of the respective genes, it should principally be reversible. The authors could establish administration of recombinant devil interferon ? as one way to trigger the immune response and suggest vaccination of devils with MHC-positive tumor cells as an ultimate measure to assure species survival.

Does this mean there is a cure to the devil’s cancer?

Felix Spenkuch

Further reading:
[1] A. M. Pearse, K. Swift Nature 2006, 439, 549.
[2] Murchison E. P. et al., Science 2010, 327, 5961, 84-87.
[3] Hannah V. Siddle et al., PNAS 2013, 110, 13, 5103-5108.

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