It is accepted by the scientific community that cancer is not caused by a single mutation in DNA, but by an accumulation of a number of mutations that result in the disease. That being said, it has been commented that some mutations are more prevalent than others in their contribution to cancer. For a long time, scientists have been puzzled by the fact that elephants appear to rarely develop cancer. New evidence has unveiled a possible explanation for why humans, as a species, appear positively riddled, whilst elephants appear to exist relatively cancer free.
One of the most prevalent mutations observed in human cancers is in the p53 gene. P53 is responsible for stopping cells from continuing to grow if DNA becomes damaged. Often called the ëguardian of the genomeí, p53 is a vital anti-cancer precaution taken by the cell. If the DNA becomes damaged, p53 stops the cell from growing, attempts to repair the damage ñ if the damage is not repairable, it will also lead the cell to die so that faulty cells are not passed on.
It is easy to see, therefore, how mutations in p53 may lead to cancer, with faulty cells continuing to grow and divide uncontrollably. This is why the gene is referred to as a tumour suppressor.
Scientists have now discovered that in elephants, there are extra, modified copies of this vital gene ñ 38 to be precise. In the case of humans, who have a meagre two copies of the gene, mutations in both copies are required to contribute to cancer. In elephants, with so many extra copies, a more significant buffer is created, protecting the cell from producing mutant p53 proteins. Furthermore, elephant cells appear to have a more robust process for disposing of damaged cells that may have become cancerous.
This is a significant step forward in natural evolutionary prevention of cancer. Co-senior author of the research, Joshua Schiffman M.D. stated: ìNature has already figured out how to prevent cancer. Itís up to us to learn how different animals tackle the problem so we can adapt those strategies to prevent cancer in people.î
Whilst it is clear that this is not a Holy Grail solution to curing human cancers ñ these are elephants after all, it adds to our knowledge of cellular turnover and tumour suppression in cancer. In addition it also sends a strong message about preserving our natural environment. It is clear that this is yet another argument for wider conservation methods and the preservation of biodiversity. Nature can sometimes provide the answers for us for some of the most devastating diseases that plight our existence.