Tasmanian Devils are threatened by a fatal Cancer and Science has just discovered the reason why
Scientists have found some amazing facts involving a common disease that attacks Tasmanian devils. devils facial tumor or DFT repeatedly attacks Tasmanian devils and is virtually incurable. However research has now found that tumor cells in the DFT possess the ability to disguise them and hide from the animals immune systems. The tumor uses a kind of molecular deception found in human cancers to build a force shield around it disallowing the immune system to recognize and attack it.
Research published recently observed how DFT cells hide from the Tasmanian devils immune system by not expressing molecules that can be recognized by the immune system. The discovery of the molecular shield provides scientist valuable data in understanding the disease so that effective medication can now be formulated to cure or prevent it.
1 Modern day immunotherapy is now the first line defense against cancer
Modern day cancer therapy besides chemotherapy and surgery also uses the process of stimulation of immune cells to target the tumor cells. 2013 saw a major breakthrough in successful immunotherapy. The procedures of stimulating Immune checkpoint molecules have advanced rapidly in regulating and improving the immune system. The therapy has now emerged as the first line of defense in cancer treatment. The benefit of checkpoint molecules is the control over the procedure that can be stopped whenever desired.The need for regulation and control is the harsh fact that the immune system is so powerful that in killing cancer cell it can also end up damaging healthy organ tissue as well.
2 Programmed death, what does it mean
Checkpoint molecules named PD-1 or programmed death-1 and PD-L1 or programmed death ligand -1 are now the most critical regulatory agents of immunotherapy against cancer. But though they are used for keeping the onslaught of the immune system in check, they are also used by cancer as a molecular shield against any attack by the immune system. This is one common factor found in the disease. PDl-1 is the main agent that works as a regulatory barrier against the cancer killer PD-1 or T-cells.Tasmanian devil facial tumor that uses this kind of molecular deception to spread.
The PD-1 molecule is common to several immune cells but is more specific to anti cancer responses that are initiated by T-cells or Lymphocytes. Each time a cancer killing T-cell interacts with PD-L1 which acts as the regulator, the action of the T-cell is stopped. The T-cell then undergoes what is known as programmed death or it could just remain idle bereft of any role. In the worst case scenario, The T-cell may also prevent other immune cells to do their job of targeting the cancer. This is what is happening in the devil facial tumor resulting in the subsequent deaths of Tasmanian Devils.
3 Tasmanian devils are affected by other disease other than Devils facial Tumor
Research teams studying Tasmanian devil immunology found such checkpoint molecules present in the devil’s immune system and were the main cause of devil facial tumor. There is a possibility of many other factors contributing to DFT that hide the disease from the immune system. Research to locate all of these is currently underway. However in a positive sign for researchers, not all cancer cells were able to hide and spontaneous tumor regression was observed in various stages of the disease.
In 2014 a second transmissible cancer was named DFT 2 was found in wild Tasmanian devils native to Southern Tasmania. This has shocked scientists as only a few transmissible cancer tumors are known to exist.
4 Protecting the Tasmanian Devil
In order to protect Tasmanian devil’s falling prey to devils facial disease 1 and 2, effective immunotherapy and research to that effect would have to be initiated so that new transmissible cancers don’t arise. For this, research is going on to find out which are the true switches that can turn on or off the immune system of Tasmanian devils to create a correct anti cancer response.
The biggest challenge is the evolution of the devils facial tumor disease that can adapt to ecological conditions and immunological pressure. The only positive aspect of such an occurrence is the reduce fatality of the disease which causes the disease not to kill the host it infects. Hopefully this will also be true in the case of the Tasmanian devil.