While about 17 percent of humans all over the world die from cancer there is less than five percent of caged elephants who are 100 percent times more prone to developing cancer cells. These tuskers who have an average life span of 70 years are bound to die from the disease. According to the New York Times, researchers have recently discovered a ‘”zombie gene” en-rooted in the elephant that is actually protecting it from falling victim to cancer.
The research teams over at the University of Chicago with evolutionary biologist Vincent J. Lynch and Dr. Joshua D. Schiffman of the University of Utah, conducting separate studies, discovered that there is a unique gene in elephants that combat cells with damaged DNA. Dr. Lynch and his team call the “zombie gene” LIF6 or leukemia inhibitory factor 6.
The discovery came about during the study of the master suppressor gene p53 in elephants. All humans and animals have one copy of the p53 gene. The gene allows humans and elephants to identify a cancer harbinger which is unrepaired DNA damage. Once recognized, those cells will officially die. Researchers have found that elephants actually carry 20 copies of the LIF gene, making them sensitive to damaged DNA. The difference between elephants and humans is that only elephants can develop LIF6, not humans. This is simply because of the animal’s gigantic size and ability to develop cancerous cells.
The multiple copies are seen to be “sloppy” mutations of the ancestors of elephants and manatees from over 80 million years ago. So, this is why LIF6 is considered to be the gene from the dead or “zombie gene.” Researchers found that the function of LIF6 is to fight damaged DNA by killing the cell. The cell goes on to make a protein that quickly goes into the mitochondria, triggering the death of the cell.
“Hence, zombie,” said Dr. Lynch via Science Daily. “This dead gene came back to life. When it gets turned on by damaged DNA, it kills that cell, quickly. This is beneficial, because it acts in response to genetic mistakes, errors made when the DNA is being repaired. Getting rid of that cell can prevent a subsequent cancer.”
Unlike LIF6, p53 can not make its own protein making it the only gene functional in elephants. Yet, p53 activates LIF6 primary function. Dr. Lynch predicts elephants are plausible to have developed new genes that recognize unrepaired DNA damage and suspects the tusker has found other ways to fight cancer without p53.