In the fight with cancer, we need any piece of help we can get. With this in mind, a group of researchers set out to investigate the animals that don’t get cancer (or rarely do) – especially elephants and naked mole rats.
At a first glance, it seems strange that elephants don’t get cancer. After all, cancer is basically a mutation of a group of cells, and elephants have way more cells than humans, but on average, only 1 in 20 elephants get cancer, compared to 1 in 5 for humans. In fact, there doesn’t seem to be a correlation between cancer occurrence and the number of cells, otherwise bigger animals would get cancer more often, and this doesn’t happen. So why are elephants special?
A team of researchers in the US looked closer and found an abundance of a gene called TP53 which they believe is important for cancer. The gene has been documented and is known for its ability to repair damaged DNA and thus halt the spread of cancer. Humans also have it, but elephants have it 20 times more; it’s an interesting correlation, although likely to be only one piece of the puzzle.
“These findings, if replicated, could represent an evolutionary-based approach for understanding mechanisms related to cancer suppression,” says the report, published in the Journal of the American Medical Association.
Naked mole rats are even more surprising: they never develop cancer, even when researchers try to induce it in a lab. Their natural mechanisms are just good at fighting cancer, at least according to a recent study. These natural mechanisms include a polymer called hyaluronan; the thickness of this polymer controls a number of cell parameters, including cell growth and mechanical strength. Researchers had a hunch this polymer was preventing the spread of cancer, so they eliminated it – and then the cancer spread as it does in other organisms – which seems to indicate that hyaluronan is crucial for fighting cancer.
“We speculate that naked mole rats have evolved a higher concentration of hyaluronan in the skin to provide skin elasticity needed for life in underground tunnels,” reads the separate report, published in Nature. “This trait may have then been co-opted to provide cancer resistance and longevity to this species.”
It’s a long shot, and it’s not yet known if this can work in humans, but studying animals that do well against cancer definitely seems like a good idea. It’s a big biological jump, but it’s definitely worth the effort.