Longevity in its most absolute form, immortality, is a recurring theme in science fiction. In reality, human life expectancy is constantly increasing. The eradication of a deadly disease such as cancer could only further extend that longevity.
The end of cancer: science or fiction?
Our bodies are made up of approximately 50 trillion cells. Whatever their specialization—whether blood, lung, or skin cells—they are all destined for the same fate: to be born, to reproduce, and to die. However, there is one type of cell that does not die: the diseased cell, the cancer cell. Although abnormal compared to healthy cells, these cells continue to reproduce, creating more diseased cells that eventually form a tumor.
If we consider a cancer cell as an accident of cellular reproduction (a healthy cell giving rise to a diseased one), we might assume that the more cells an organism has, and the more those cells have divided, the greater the likelihood of errors occurring. In that case, large animals—especially those that live long lives—should be more affected by this “numbers game.”
But this is not what is observed at all. Humans are no more prone to cancer than mice, and even more strikingly, elephants—whose bodies contain far more cells and who live much longer—are up to five times less susceptible to cancer. In this regard, they hold a remarkable record. How is this possible?
Scientists have discovered that elephants possess a powerful ally known as TP53.
TP53 is a gene that monitors the DNA of cells. DNA is the molecule that carries genetic information, passed from cell to cell across generations. When TP53 detects a cell with damaged DNA, it takes action and, depending on the situation:
- repairs the damage
- halts the cell lineage by blocking cell division
- triggers self-destruction
This is how TP53 earned its status as a tumor suppressor gene.
While humans have one TP53 gene, elephants far surpass us, possessing around 20 copies. This may explain the difference in cancer susceptibility between our species.
“Nature has already figured out how to prevent cancer. Now it’s up to us to learn how different animals solve this problem so we can adapt these strategies to prevent cancer in humans,” concludes Dr. Schiffman, one of the researchers who studied TP53.
Source:
Les Dossiers Sciences et Univers – Issue 5, February–April 2016 – “Defeating Cancer Thanks to Elephants,” p. 83
Additional sources:
The incredible defense of elephants against cancer explained
https://www.sciencesetavenir.fr/animaux/grands-mammiferes/l-incroyable-defense-des-elephants-contre-le-cancer-elucidee_102072
