In an August 14, 2018 study, researchers published a paper in Cell Reports revealing that elephants have evolved to make a non-functioning gene called LIF6 (leukemia inhibitory factor) come back to life which makes them mostly immune to cancer. Scientists say that this discovery could be applied to cancer resistance for human cancer biology.
The study refers to the elephant’s LFI6 as the ‘zombie’ gene, that once switched on, can efficiently kill cells that could become cancerous.
According to a press release from the study, author Vincent Lynch, a geneticist and evolutionary biologist at the University of Chicago, says that elephants get cancer far less than expected considering their size. Lynch notes that their research found that elephants and their relatives have many non-functioning copies of the LIF gene, but that elephants have evolved in a way that turns one of the copies, LIF6, back on.
The study notes that the scientists made this discovery by introducing cancer-causing DNA damage to cells in elephants and its smaller relatives like the manatee and hyrax to see if the elephant cells responded differently to the threat of cancer. By using the smaller species related to the elephant, researchers could isolate elephant-specific genetic variations and focus on which ones could be associated with cancer suppression.
In the paper, Lynch says that the elephant cells died but were also entirely intolerant of DNA damage in a way their relatives’ cells weren’t, and because the elephant cells died as soon as their DNA was damaged, there was no risk of them ever becoming cancerous.
The scientists say that elephants aren’t the only animals that have evolved cancer resistance and cite whales, bats, and naked mole rats that have developed cancer resistance but using a different strategy than the elephants ‘zombie’ gene.
