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Once Thought Immune to Cancer, Naked Mole Rats Found with Tumors

ByTim De ChantNOVA NextNOVA Next

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Until a few weeks ago, naked mole rats were hailed as a medical miracle, of sorts—no one had ever found cancer in the big-toothed, small-bodied rodents. It was hoped that if we could figure out why, we might have a better chance at fighting it in humans.

And while the rodents are still a marvel, their mystique has been shattered, if slightly: Two naked mole rats kept in zoos have been found with cancer.

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Naked Mole-rat
A naked mole rat kept at the Smithsonian National Zoo

One naked mole rat housed at the Brookfield Zoo in suburban Chicago was diagnosed after it had been euthanized. (It had a nasty facial rash that wouldn’t go away and was losing weight despite the veterinary staff’s best efforts). Pathologists investigating its death found a slow-growing stomach cancer in tissues samples collected after it died.

The other patient, kept at the Smithsonian National Zoo in Washington, D.C., gives reason for hope, though. After having a malignant tumor removed from a gland in its armpit, three months later the 22-year-old naked mole rat was found cancer-free later

Here’s Nicholas St. Fleur, reporting for the New York Times:

“Now that we have two naked mole rats with cancer,” [lead author Martha Delaney] said in an email, “we can study the colonies from which they came to elucidate why they are cancer prone, compared to other zoo and research colonies.”

Dr. Delaney and her colleagues have been studying naked mole rats for years, searching for clues as to why the little pink rodents could live so long, relatively speaking. While most of their evolutionary kin die after a few years, naked mole rats can live up to three decades or more.

This latest discovery may seem like a setback, but it could provide clues as to why naked mole rats are so successful at warding off cancer, even if some eventually succumb to it.

Photo credit: Smithsonian National Zoo