The team noted that over half of all cases of uncontrolled division of abnormal cells in humans are missing functional p53, another important clue to its importance in suppressing the disease. They should also have 100 times the chance of developing cancer. Lynch thinks that the extra copies evolved as the lineage that led to elephants expanded in size. It was like cell death or cell suicide. Moreover, elephants can survive for more than 60 years in the wild, providing plenty of time for tumors to arise.
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A recent study conducted by researchers from the Huntsman Cancer Institute (HCI) at the University of Utah, found information of why elephants are resistant to cancer. “But they don’t or they’d go extinct”.
Previous research has suggested that specific molecular mechanisms in elephants protect them against cancer, though Dr. Schiffman and colleagues note that such mechanisms are poorly understood. Nearly all other species-including humans-have only one. “Organisms with long lifespans have more time to accumulate cancer-causing mutations than organisms with shorter lifespans and therefore should be at an increased risk of developing cancer”.
Joshua Schiffman, co-author of the study, said that TP53 is crucial in cancer prevention because it scans cells for genetic errors and destroys those that are unable to be repaired. But now, new research might shed light on our big-eared friends’ super cancer-fighting abilities.
In the first part of the study, the researchers looked at 14 years worth of necropsy data from the San Diego Zoo.
And yet, the analysis of a large database of elephant deaths showed that less than 5 per cent of elephants die of cancer, compared to 11 to 25 per cent in people.
One of these alarms is called TP53, and while humans have one TP53 gene, elephants have 20. Compared with human cells, elephant cells demonstrated increased [cell suicide] response following DNA damage.
The fascinating results are now published in JAMA, the prestigious, peer-reviewed Journal of the American Medical Association.
Maley, an evolutionary biologist at Arizona State University, discovered that African elephants have 20 copies of a genome called TP53, a gene that appears to be involved in tumor suppression.
Elephants, the researchers found, receive 20 copies of the TP53 gene from each parent.
Schiffman specializes in treating children missing one of their TP53 gene’s two alleles, which leads them to develop cancer.
“We’re trying to be pioneers, to use these discoveries to do precision medicine”, says Schiffman. But the animals’ cells weren’t any better than human cells at fixing broken DNA.
To test this, the researchers did a side-by-side comparison with cells isolated from elephants (n=8), healthy humans (n=10), and from patients with Li-Fraumeni Syndrome (n=10).
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A good example of this theory is the disparity in cancer incidence between humans and elephants; despite elephants being significantly larger than humans, their risk for cancer is much lower. However, if future study confirms it, scientists could work on drugs for people who would mimic the effect. There, they found 40 genes that contained p53.
