Zombie genes may sound like a terrifying prospect, but it actually helps elephants survive cancer at a much higher rate than humans.
This impressive quality of elephants has always been intriguing to scientists, especially since anything that helps the majestic animals survive may be key in discovering a cure for the deadly disease.
According to the University of Chicago, about 17 percent of humans die from cancer, while less than 5 percent of captive elephants die from the disease. The huge disparity in survival rates baffled scientists since the massive creatures are much larger and have a lot more potentially cancerous cells than humans.
The reason for this, scientists found, is two-fold.
Findings Of A Previous Research
Three years ago, two separate teams discovered that humans and animals possess the master tumor suppressor gene p53, which allows the body to detect unrepaired DNA damage — a known precursor to cancer — and kills the damaged cells.
Elephants have 20 copies of p53, making them extra sensitive to the damaged DNA and helping them avoid the disease.
New Study Shows How A 'Zombie' Helps Elephants Stay Alive
The study, published in the journal Cell Reports, reveals another significant factor in the animal's success against cancer: a so-called zombie gene that works alongside the p53 to kill damaged cells.
When genes reproduce, they sometimes make "mistakes" or non-functional versions that scientists have dubbed as pseudogenes or dead genes. One such pseudogene found in elephants is the leukemia inhibitory factor 6.
The LIF6 is a psedogene that has somehow found a second "life" as a working gene. When activated by the P53, this zombie gene releases a protein that targets the mitochondria, poking holes into it until the cell dies.
"When it gets turned on by damaged DNA, it kills that cell, quickly," Vincent Lynch, senior author and assistant professor of human genetics at the University of Chicago, explains in a statement from the university. "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."
The researchers found that elephants actually have eight LIF genes, but only LIF6 has shown to be functional.
Scientists believe that the zombie gene developed when the smaller precursors of modern elephants began to grow larger. It helped them combat the dangers of having more cells and more opportunities of mutations that come with a bigger body.
Implications On Human Cancer
The findings on elephants and how they fight cancer can play a significant role in the search for a cure in humans as well. The new study and further research on p53 and LIF6 can pave the way to developing drugs that mimic the functions of these two genes naturally found in elephants.
However, any new treatment arising from these findings will likely take a while to develop and hit the market, according to Lynch.
"Developing new drug treatments is a very complex process and it takes decades," Lynch explains to ABC News. "We always hear the news that there is some discovery and that a new treatment based on that discovery is five to 10 years away but it's never five to 10 years. So this is going to be a very very long process."