The ‘Zombie’ Gene in Elephants: How a Resurrected Pseudogene Fights Cancer
Elephants are amazing animals…not only because of their size and intelligence, but also on the basis of their incredible resistance towards cancer. They have gigantic bodies and long life spans, but cancer is uncommon in them, and scientists have long been puzzled by this phenomenon.
The answer is not where one would think. It’s in a “zombie” gene that rose from the dead to protect them. If you play Dragon Slots on the weekends with all your friends, you too can revive your passionate ambition to be the very best at betting!
Why Don’t Elephants Get Cancer?
Having 100 times as many cells as humans, these creatures should be loaded with cancer, but fewer than 5 per cent of them succumb to the disease.
This was termed as Peto’s Paradox (named after British epidemiologist Richard Peto) when he noted that bigger animals did not always exhibit more cancer mutations. How, then, do elephants evade it? The secret is in their genes, specifically, a resurrected “zombie” gene called LIF6.
The Role of the TP53 Gene
Before we discuss these genes, we have to learn what TP53 is. It is a very important tumour suppressor. While human beings possess a single copy of it, elephants possess 20 copies. It monitors the damage to the DNA and either arrests the cell cycle to repair it or initiates the cell death process lest the wounds become too severe.
With so many TP53 genes, elephants have a supercharged defence system, but TP53 doesn’t work alone, as it needs help from a once-dead gene: LIF6.
The Rise of the Zombie Gene
A LIF6 is a pseudogene, a type of gene that has lost its functionality. The majority of pseudogenes are actually evolutionary leftovers, genetic fossils, although in elephants, LIF6 has been reanimated, thus its label as a zombie.
When flaws in DNA are apparent, TP53 activates LIF6, which is the creation of a functional protein. It makes holes in the mitochondria, which are the energy factories within the cell. The objective is that the impaired cell self-destructs prior to becoming cancerous.
Consider it as an emergency kill switch, and TP53 raises the alarm, whereas LIF6 provides the death strike. In the absence of this zombie gene, cancer resistance in elephants would not be as excellent as it is.
Could This Help Humans Fight Cancer?
Understanding LIF6 opens exciting possibilities for human medicine. While we can’t give people 20 copies of TP53 or resurrect their pseudogenes, scientists are exploring ways to mimic this defence system.
Potential Treatments
Researchers are studying:
- Drugs that activate TP53 in human cells.
- Gene therapies to introduce cancer-killing mechanisms like LIF6.
- Synthetic biology to create artificial tumour suppressors.
How Scientists Discovered It
The discovery of LIF6’s role in cancer resistance was a breakthrough in genetic research. To investigate, they analyzed elephant DNA to see if they had a lower rate of mutation than other large animals. They found many copies of TP53, which sparked further study.
They then examined how this gene functioned in the animal’s cells and noticed that when DNA damage occurred, a specific pseudogene (LIF6) was activated. This was surprising because pseudogenes are usually inactive. Further tests proved that this produced a functional protein that destroyed damaged cells.
The term zombie gene was used because LIF6 was apparently dead (non-functional) in the vast majority of mammals, yet reawakened in elephants via evolution. In 2018, the publication of the discovery in Cell Reports established new possibilities.
Other species have also helped scientists uncover different ways nature prevents tumours, like Naked Mole Rats. These rodents live up to 30 years (far longer than similar-sized animals) and almost never get cancer. They produce a special sugar (hyaluronan) that prevents cells from dividing uncontrollably.
