A study found that cancer rates in elephants are far lower than in humans. Elephants are far larger animals and have more cells, therefore this fact always surprised scientists. The research was published in the Journal of the American Medical Association.
A team of researchers think that they have found an explanation, and that one day it may help us find new ways to protect humans from cancer as well. Humans only have one copy of an important gene that suppresses cancer, whereas elephants got 20 copies of them. The statement was confirmed by two different scientific reports. This specific gene, called p53, helps damaged cells self-destruct when they are being exposed to cancerous substances.
The p53 gene makes elephants far more resistant to cancer than any other mammals, and if more studies will confirm this, researchers could develop a p53-based drug that would help humans prevent or even fight cancer.
One of the studies was initiated when Dr. Joshua Schiffman, a cancer expert at the University of Utah, first heard a lecture about Peto’s paradox. Peto’s paradox refers to the fact that the largest animals on Earth, have lower cancer rates than smaller animals, even though they have more cells than them. Cancer rates in whales and elephants are much smaller than in other mammals.
Schiffman gathered blood samples from 8 elephants and compared them to blood samples of children who suffer of a condition called Li-Fraumeni syndrome. These children are very sensible to cancer infections due to their incomplete or lack of p53 genes.
By that time, a second team of scientists also arrived to the same results: elephants have 20 copies of the p53 gene, whereas humans and other mammals only have one copy.
Schiffman’s team compared how elephant and human cells react to radiation and substances that induce cancer. The researchers also compared the cells of healthy humans to those of Li-Fraumeni syndrome sufferers.
The experiment showed that elephant cells have a much faster self-destruction rate when it is exposed to radiations or carcinogens. The rate is twice as fast in elephants than in healthy humans, and up to five times the rate of Li-Fraumeni syndrome sufferers. Cells that do not self-destruct in time when they are exposed to carcinogens allow the cancer to develop faster in the body.
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