Why do elephants have a low cancer rate?
"Zombie gene" is the key
Guide
Elephants have the same life expectancy as humans, about 70 years. In general, the larger the volume, the greater the number of cancer cells in the body. It is estimated that up to 17% of people worldwide die from cancer, and the probability that an elephant with 100 times more cancer cells will die from cancer is only 5%! What is the reason? Recently, the University of Chicago team found that a "zombie" gene in elephants is the key to their freedom from cancer.
Humans, like all other animals, have a major tumor suppressor gene, P53. This gene enables humans and elephants to recognize unrepaired DNA damage (which is a precursor to cancer) and then remove these damaged cells.
Three years ago, a research team from the University of Chicago began researching this. The most surprising finding during the period was that there were only 20 copies of P53 in the elephant compared to the only copy of P53 in most animals. ! This makes their cells more sensitive to damaged DNA and can clean damaged cells more quickly.
In the August 14 issue of Cell Reports, the team described the second element of elephant resistance to cancer: they discovered an anti-cancer gene, LIF6, that has recovered from the death gene.
Dr. Vincent Lynch, assistant professor of human genetics at the University of Chicago and senior author of the study, said: "Genes are constantly replicating themselves, but sometimes replication errors occur, producing non-functional pseudogenes. We often call these dead genes (dead Genes)."
However, it is not. When studying the elephant P53 gene, Lynch and colleagues found that this dead gene, called leukemia inhibitor 6 (LIF6), somehow evolved a new switch. And the LIF6 that escaped into the body turned into a valuable work gene!
When P53 is activated, the LIF6 gene produces a protein that quickly enters the cell's main energy plant, the mitochondria, and digs holes in the mitochondria, which in turn kills the corresponding cancer cells. Further research found that elephants have eight LIF genes, but it is known that only LIF 6 is functional and seems to have been functioning for a long time.
Image source: Cell Reports
"This dead gene is revived like a zombie. When it is reactivated by damaged DNA, it quickly kills the corresponding cancer cells. Lynch said, "This is beneficial because it responds to genetic errors and prevents it." Related cancers. ”
Not only that, but this remedy for cancer suppression may also be a key factor in making elephants so versatile. The researchers explained that the fossil record shows that the elephant's predecessor was the size of a small marmot between 25 and 30 million years ago. With more cells, the body will gradually become larger and eventually lead to the emergence of modern elephants.
However, larger animals have more cells, and they tend to live longer, which means higher chances of accumulating carcinogenic mutations. Large long-lived animals must evolve powerful mechanisms to suppress or eliminate cancer cells in order to live longer and reach adult size. Researchers believe that LIF6 may be an important reason for maintaining the balance between large animal size and cancer.
Finally, the mechanism by which LIF6 induces apoptosis is still unclear. The author points out that this will be the focus of future research.
Article reprinted from：https://news.pharmacodia.com/news/html/info/info-detail.html?id=28971
