Resistance to Cancer in Elephants

The paper I chose to summarize involves a study done on elephants to determine why they rarely get cancer. For decades elephants have been known to be super resistant to cancer and until recently no one knew why. Researchers from University of Utah and Arizona State University in collaboration with Ringling Bros. Center for Elephant Conservation believe they have found the answer. The secret seems to lie in the DNA code of elephants. The DNA of the largest land animal on Earth contains 38 copies of a certain gene that codes for p53, which is a tumor suppressor. Thirty-eight that is, compared with just two copies in humans. Furthermore, the researchers believe that elephants may have a more aggressive way to target and destroy pre-cancerous cells. Joshua Schiffman, a co-senior author, says, “Nature has already figured out how to prevent cancer. It’s up to us to learn how different animals tackle the problem”. For many years elephant health has been a real mystery. Because elephants have about 100 times more cells overall compared to humans, they should be 100 times more susceptible to a cell malfunctioning and becoming cancerous. This study also confirmed, by looking at a large database of elephant deaths, that elephants die of cancer between two and five times less often than humans. That is, elephants have a 5% cancer mortality rate compared to between 11% and 25% in humans. The researchers analyzed the genome of the African elephant and discovered at least 40 variations of the cancer suppressing gene p53, 38 of which are retrogenes meaning they are variations of the same basic gene. The researchers also drew blood from many of the elephants and performed some interesting experiments. One experiment they did was subjecting the DNA of the elephants to damage which can be a facilitator of cancer. The elephant cells reacted by committing apoptosis. The researchers mentioned that because elephants are so massive and have so many cells they should be extinct by now due to the increase in risk of cancer. They believe that the elevated levels of the p53 gene is natures way (through evolution) of preventing cancer. Humans with Li-Fraumeni disease contain only one active p53 gene (as apposed to the normal two), and the researchers compared the blood tests from the elephants with humans who suffer from the disease. They found that after subjecting the DNA of both groups to damage the elephant cells committed programmed death five times more often than human cells from people with Li-Fraumeni disease. The researchers concluded that more p53 expression may lead to a much stronger resistance to cancer. As usual more research is needed to fully understand exactly how this gene could be used or studied to help better resist cancer in humans I just hope elephant blood doesn’t become as valued as their ivory.

ARTICLE REFERENCED:

http://jama.jamanetwork.com/article.aspx?articleid=2456041

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About ben james

"The stars keep me up at night" -some song I heard one time Human. Studying the intersection of Neuroscience and Computation. Wanna be (astro) physicist.
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