Why don't elephants get cancer?

It has long been known that elephants develop cancer much less frequently, and the reason has been a matter of curiosity. Recent research has shown that elephants possess an advanced cancer-protective mechanism.

It was once accepted that cancer risk increased with increasing body size in animals. However, research published by a scientist named Peto 40 years ago found that there is no relationship between body size and cancer risk . This finding is also known as Peto's Paradox . Elephants form the basis of the research.

Elephants have 100 times more cells than humans. In this context, the increased number of cells should cause an increased cancer risk. However, the cancer incidence rate is 5 percent in elephants, compared with 25 percent in humans. A study published in October explained the underlying reasons for the very low occurrence of cancer in elephants.

According to the research results, elephants have extra genes in their genetic makeup, and these genes play an important role in stopping tumor growth . The gene the researchers focused on is TP53. Humans have two copies of the TP53 gene, one from the mother and one from the father. Elephants were discovered to have 40 copies of this gene. TP53 (Tumor Protein 53, also known as p53) is a tumor suppressor gene of critical importance in cancer. Because of this importance, scientific authorities have named it the molecule of the century and the guardian of the genome .

The primary function of the p53 gene is to prevent tumor growth. When damage occurs in a cell's genetic information, it stops cell division to prevent uncontrolled division and initiates mechanisms to repair the damage. If the damage is beyond repair, it eliminates the cell through programmed cell death called apoptosis. In more than 50 percent of human cancers, the p53 gene has been found to be mutated. For p53 to perform its function, both copies inherited from the mother and father must be intact. If one of the two copies is damaged by a mutation, p53 cannot perform its function. This syndrome is called Li Fraumeni Syndrome . These individuals have a very high risk of developing cancer.

Researchers exposed blood samples from healthy people, people with Li Fraumeni Syndrome and elephants to radiation to determine cell death rates. Because p53 is active in healthy cells, damaged cells exposed to radiation are expected to die. The lowest cell death is expected in patients with Li Fraumeni syndrome, in whom the p53 gene is inactive. As expected, the research results showed the highest cell death in elephant blood cells, at 14.6 percent. Cell death occurred in 7.2 percent of cells from healthy humans and 2.7 percent of cells from people with Li Fraumeni Syndrome. These results showed that elephants eliminate their damaged cells before they lead to cancer, and do so using their extra p53 genes.

So what new possibilities might all these findings offer for cancer treatment?

Until now, cancer research has focused on humans. However, studying different living organisms may pave the way for p53-focused cancer therapies. Nature may already have discovered mechanisms that prevent cancer development!