Among all animals, elephants have frequently delivered a contradiction to biologists. They are much bigger than humans, not to mention that they live for a similar length of time, and yet, they rarely develop chronic illnesses like cancer.
That, a report from The Economist said, "is odd." After all, it specified, cancer is "something of a numbers game." This means that the more cells, the more duplications there are. The more replications, the greater the possibility of DNA damage and a cell that goes rogue, failing detection and eventually beginning the runaway process towards a tumor.
The work led by the Autonomous University of Barcelona's Konstantinos Karakostis, points to an answer, at least for elephants, "to Peto's paradox."
This lack of size-to-cancer correlation is named after British epidemiologist Sir Ricard Peto, who first noted it in the late 1970s.
'Giants' of the Animal Kingdom
A CNN report specified that one would think elephants would be developing cancer left and right. They are considered the "giants of the animal kingdom," not to mention that they have trillions more cells compared to humans. Theoretically, these cells could turn into cancer over their 10-year lifespans.
However, people thinking this way are wrong. It is not that these creatures never develop cancer, although less than five percent of elephants die from it, as against up to 25 percent of humans.
According to Dr. Joshua Schiffman, a pediatric oncologist, a professor of Pediatrics at the University of Utah, and an investigator at Huntsman Cancer Institute'.
Researchers such as Schiffman examine animals that have developed ways to resist cancer naturally despite their large size and longevity, which include bowhead whales and elephants. The former can live up to 200 years.
'Zombie' Gene
By picking apart genes' and molecules' inner workings in the animal kingdom, researchers hope to solve new ways to avoid or even treat human cancer.
This is where the field moves in general, explained Schiffman. He added if they can understand how such genomic changes are contributing to cancer resistance, they'll then be able to begin thinking about the manner this is translated to patients.
A study published in the Cell Reports journal revealed that a possible mechanism could be a so-called "zombie gene" that, when brought to life by DNA impairment, causes the cell to die off. If that particular cell is killing itself, then that damaged DNA never can ultimately give rise to cancer.
This zombie gene emerged from the "pseudogene," an inactive or mutated copy of a normal gene that can gather over eons of evolution.
On-Off Switch
Elephants, and close living relatives like manatees, among others, have numerous replications of a gene called LIF, although such copies do not work like the original.
Nevertheless, in elephants, one copy appears to have reanimated and developed a new on-off switch responding to DNA damage. The study findings are composed of a single piece of a bigger puzzle.
The authors of the study said, perhaps, there are lots of things that can contribute to the augmented resistance to cancer, and they discovered one of them in elephants.
Information about elephants rarely having cancer is shown on Ringing Bros. and Barnum & Bailey's YouTube video below:
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