The Asian elephant has an average lifespan of 60 years; the African subspecies, 60 to 70 years. An animal roughly double the height of a human and thousands of pounds heavier lives to comparable ages, but scientists have found their cancer mortality rates are far lower than man’s — 4.8 percent in elephants versus up to 25 percent in humans. Researchers have discovered how the creatures are capable of such health, which could lead to improved cancer treatments for people.
A research paper published online in the Journal of the American Medical Association on Oct. 8 shows that conventional wisdom isn’t very wise. While most would reason that an animal’s cancer rate increases as its body size increases (more mass equals more cells equals more cells that can grow abnormally) or as its lifespan increases, longevity and size don’t necessarily elevate an animal’s risk. Elephants are the largest land mammals on Earth, and one of its longest-living, yet their cancer rates are suprising low.
The average cancer mortality for elephants is 4.81 percent, ranging from 3.14 to 6.49 percent. Humans on the other hand, with a cell count 100 times less than an elephant, have a cancer rate between 11 and 25 percent. That’s because elephants don’t try to suppress their cancerous cells; instead, they just destroy the cancer cells and go on. The secret to their relative health is the TP53 gene; elephants have 20 pairs of in their genome. According to Live Science, the gene, nicknamed “the guardian of the genome,” encodes a protein that suppresses tumors.
Humans have the gene as well, but only one pair. That pair is often mutated, leading to cancer’s reproduction and spread. The elephants’ redundancy of genes allows it to better protect itself from cancer.
What this means for science remains to be seen. Researchers and commentators on the discovery have already expressed their doubts as to whether “new” cancers like lung cancer from smoking or diet-related cancers can be cured. Their relatively recent introduction into man’s genome means the cancer cells may not respond as well to cancer suppression from TP53. Other cancers may be treated via gene therapy. Only time will tell, but the find is a step in the right direction.
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