LIVERPOOL, England — In the oncology and, more broadly, the biology world, the naked mole rat is exceptionally fascinating. Native to East Africa, these wrinkly, hairless — some might say unsightly — creatures have long lifespans for small rodents, and they’ve been found to be remarkably resistant to cancer. Now a new study may have uncovered the reason why, pointing to cellular processes that boost their unparalleled resistance.
Typically, the cancer rate in animals is the same as or higher than that of humans. But, after several decades of being studied by scientists, very few naked mole rats were found to develop cancerous tumors. What’s more, naked mole rats live up to about 32 years, as much as 10 times longer than other rodents.
To help understand why, an international group of researchers studied the naked mole rat to see if it possessed the anti-cancer mechanism known as cellular senescence. This process helps protect against the spread of the disease by stopping cell division when cells divide too quickly and become out of control, which leads to the development of cancerous tumors. In other animals, such as mice, senescence actually hastens the aging process, leading to shorter life spans, because cell division is halted.
“In humans, as in mice, aging and cancer have competing interests,” explains co-author Vera Gorbunova, a biology professor at the University of Rochester, in a news release. “In order to prevent cancer, you need to stop cells from dividing. However, to prevent aging, you want to keep cells dividing in order to replenish tissues.”
Prior research showed that older mice were far stronger when researchers tested what would happen when senescent cells were removed. This led scientists to wonder how naked mole rats’ cells might be different compared to other rodents because of their long, generally cancer-free lives. Perhaps, they thought, these animals evolved to not have senescent cells at all.
The authors found that the naked mole rats did in fact have these unique cells and that the senescence process is also the same as in mice. However, they noticed distinct features exclusive to the mole rats’ senescent cells themselves that they they think contribute to their long lives and cancer resistance.
“In naked mole rats, senescent cells are better behaved,” says Gorbunova. “When you compare the signals from the mouse versus from the naked mole rat, all the genes in the mouse are a mess. In the naked mole rat, everything is more organized. The naked mole rat didn’t get rid of the senescence, but maybe it made it a bit more structured.”
Adds Dr. Joao Pedro De Magalhaes, a co-author of the University of Liverpool’s Institute of Ageing and Chronic Disease: “In addition, naked mole rat cells are more resistant to DNA damage. Therefore, one hypothesis is that the way naked mole rats are better able to cope with damage to their genome is essential for their longevity and cancer resistance.”
So as scientists across the globe work feverishly to develop various cancer-fighting solutions, it may be that the secret to immunity lies in a tiny, hairless rodent.
The full study was published in the journal Proceedings of the National Academy of Sciences.