Elephants have 100 times more cells than a human, and while they live an average of 70 years, those cells have plenty of time to mutate and become cancerous. Less than 5% of elephant deaths are from cancer. What do elephants have that humans don’t?
A study published in JAMA this week explains how scientists discovered that African elephants have 20 copies of gene TP53, a protein that suppresses tumor growth. This condition is called Peto’s paradox. When DNA is damaged, the protein stops the cells from dividing and destroys the cell. Humans have only one copy of this gene, half coming from each parent. If one allele is defective, cancer will develop at some point.
This study was largely funded by Ringling Bros. and Barnum & Bailey Circus with cooperation with the zoo in Salt Lake City. When white blood cells from elephants and humans were exposed to radiation, the elephant cells died much faster than human, as the tumor-suppression strategy of TP53 is to have the damaged cell destroy itself to prevent any mutations.
These findings are exciting due to the possibility of increasing the protection of TP53 in humans and prevent cancerous mutations in our cells. Options could be to develop a drug that acts like TP53 or to insert TP53 genes into precancerous cells.
Netburn, Deborah. “What elephants can teach scientists about fighting cancer in humans.” Science. Los Angeles Times, 8 Oct 2015. Web. 11 Oct 2015.