What is p53?
Also known as a tumor protein or a cellular tumor antigen, p53 (also sometimes called TP53) is a gene that codes for proteins which in essence keep cancerous tumors from forming. Along with another cancer-suppressing gene, CHEK2, p53 acts to “check” the DNA of damaged cells for signs of dangerous mutations and determines whether the cell will be repaired or whether it will self-destruct through apoptosis. Though the procedure is obviously far from perfect- and while it won’t help much to protect people who engage in potentially cancer-causing activities, such as smoking- it is a major component in the body’s processes to protect itself from cancer.
Humans usually inherit two copies of this gene, one from each parent. In very rare cases, however, only one copy of p53 is passed down; individuals who have this genetic anomaly, known as Li-Fraumeni syndrome, are considered to be predisposed to cancer. By studying the patterns of diseases found in people with Li-Fraumeni syndrome, scientists hope to achieve a greater understanding of the p53 gene and, through it, potential new methods to combat cancer. But the most promising recent discovery in this field has little to do with human genetics at all- instead, it’s all about elephants.
What do elephants have to do with p53?
Scientists have long been aware of the interesting relationship between elephants and cancer- that is, that they only very rarely develop it. Considering the mass of these animals, which weigh in as the largest land mammals on Earth, it seems that the opposite should be true; common sense, at the very least, suggests that creatures with more cells to develop cancer in should have a greater instance of actually having cancer. What actually happens turns out to be the opposite; less than one out of every twenty elephants die of cancer, compared to around one out of every four humans. Clearly, something is swaying the odds.
Now, scientists believe they’ve discovered what that something is. Elephants- compared to humans- have extra copies of the p53 gene. While humans, as stated above, typically only have two, elephants have been found to have as many as forty- and researchers believe that this is what’s behind elephants’ near-universal absence of cancer.
Why is this important?
Unfortunately, we can’t simply transplant elephant genes into humans, or tweak every embryo’s genetics to produce extra cancer-fighting copies of p53. At the moment, all studies of p53 are just that- studies. However, in the past, scientists have made incredible steps forward in medical research by studying other organisms. The discovery of elephants’ p53 genes could potentially help lead to development of new methods of cancer resistance in humans.
Additional Information:
- Infographic: P53 Guardian of the Genome – Ricochet Science
- NCBI Information on P53
- Why Elephants Don’t Get Cancer – NBC News
- How Elephants Avoid Cancer – Nature
Photo Credits
- elephant photo : By HRUDANAND CHAUHAN (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons
Kayla Windelspecht is a student at North Carolina State University where she is majoring in life sciences and biochemistry. Kayla is responsible for assisting with background research for many of our articles in genetics, as well as occasionally preparing some short pieces for the site.
