I was always fascinated by the cartoon character of the Tasmanian Devil. It has the classic lines of a naughty, rowdy, energetic devilish sort of look to it.
But then I found out after some reading that these are actually carnivorous marsupials and exist in the real world in Tasmania. They have a stocky and muscular build covered by a black fur, exude a pungent odour, are extremely loud with a annoying screech, a very keen sense of smell, and they feed with an unmatched ferocity. These creatures actually exist but have a shortened life span. Most die by four years of age. In the 1996 it was discovered that the Tasmanian Devils were developing a devil facial tumor disease (DFTD) that restricted their ability to feed and the cause of death was from starvation and organ failure. The facial tumors when studies revealed molecular characteristics of the Schwann nerve cell.
The declining population of the Tasmanian Devil was attributed to the DFTD.
The devils are a promiscuous lot and those dominant keep a tight control on their female counterparts. The mating process leads to a lot of biting among the competitors and the male and females. The biting was noted to be the mode of transmission of the DFTD. SO here was a cancer that was transmitted by contact in a marsupial. Interestingly facing extinction the females that normally became sexually active at 2 years of age now started to become pregnant at age 1 and then soon died after the mating period by age 2 or 3. The population of the devils rapidly decreased raising an alarm and thus rendering the Tasmanian Devil as endangered species in 2004.
What interests us is the mode of transmission. Up until now we humans were peripherally interested in this phenomenon. ”Ah the poor devils, what a terrible fate to suffer from their sexual appetite,” one would say and move on. But then this article appeared about breast cancer cells and suddenly the alarm bells should be going on. The bell has been rung and cannot be un-rung!
It turns out that breast cancer cells based on this study exude exosomes, encapsulated vesicles, with their waste-products of short fragments of their RNAs. These exosomes when transplanted or via endo-phagacytosis find themselves within the interior of a normal cell have the capacity to override the nuclear machinery of that cell and convert it into a cancerous cell. It has been previously known that the exosomes transfer chemotherapy resistance, but this is the first link of transfer tumorogenesis.
This finding has tremendous relevance to our way of thinking. Cancer transmission is more than genetic mutations passed down through generations or acquired sporadically through external influences such as chemicals and viruses and other such products of nature and man. It now appears that cancer cells by virtue of their ability to discard their effete products can do the same! ( http://www.cell.com/cancer-cell/abstract/S1535-6108(14)00368-7 ) and ( http://www.nature.com/news/cancer-cells-can-infect-normal-neighbours-1.16212 )
Maybe it is time to rethink our strategies and include a mechanism to subvert the cancer cell exosome production and extrusion and it's accumulated detritus that would choke off a cancer cell’s survival. Maybe?
Interesting to ponder upon, don’t you think?