New findings by Vazquez and colleagues (2018) suggest that one of the genes found in elephants actually serves to protect the elephant from cancer. Supposedly, elephants should have a greater risk of cancer due to their size and long life span – however this is not the case. This holds with Peto’s paradox, i.e. there is no correlation between body size (number of cells) and cancer risk across species. In the case of elephants, this may be the result of evolving cancer protection mechanisms to accommodate their body size.
One of these mechanisms may be the LIF-6 gene expression in response to DNA damage. The LIF-6 gene induces apoptosis which kills off the damaged cells before they can multiply and lead to cancer. The TP53 protein is known to induce the production of the LIF-6 gene when cellular damage occurs. While the LIF-6 gene is found only in elephants and their evolutionary relatives, the TP53 protein is found across animal species. Elephants have 20 copies of theTP53 protein where humans have only one. Further exploration of the TP53 protein and LIF-6 gene is needed to understand exactly how elephants fight cancer. Perhaps this research could be applicable to the development of the TP53 protein research in humans.
The study recently published in Cell Reports can be accessed here: https://doi.org/10.1016/j.celrep.2018.07.042