Two creates with very low cancer rates have scientists asking why.
Elephants, for instance, have 100 times the number of cells of a human, but experience cancer 1/4 as much. Assuming that it is an issue with the cells, themselves, what have elephants got that makes their cells less likely to go into overgrowth mode?
The answer could be a specific gene called TP53, found in abundance in elephants. 20 times more prevalant in elephants than in humans, this gene is responsible for repairing damaged DNA, which can lead to a cell becoming less likely to disrupt and become cancerous. It is believed that elephants have evolved more of these genes to protect calves born to older mothers.
"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.
Even more intriguing than the elephant, though, is the naked mole-rat. Naked mole rats never get cancer. Even when scientists try to induce it in a laboratory setting, their cells stay healthy. This, seemingly, bizarre feat of nature has been traced to one chemical called hyaluronan, which makes their cell walls stronger but also regulates their growth. When scientists have eradicated the chemical from the mole-rat's system, they have been able to produce cancer, so it is believed that hyaluronan plays an integral role in cancer prevention.
"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."
Though it is a jump, from humans to elephants to mole-rats, watching these chemicals in action and applying them through gene therapy may give us a better basis of cancer prevention in the future.