Despite the critters' 30-year lifespans, naked mole rats have never been found with tumors, and are the only known mammals that don't get cancer. Researchers at the University of Rochester in New York added cancerous cells to naked mole rat cells in order to observe the mechanism that inhibits cancerous growth. The growth of cancer cells in humans is inhibited by a gene known as p27, a gene that the naked mole rat also employs to inhibit cancer growth. But the gene primarily responsible for inhibiting cancer cell growth in naked mole rats is p16-ink4a, a gene humans also possess, but which plays no role in inhibiting cell growth in humans.

And the benefits for naked mole rats go beyond avoiding cancer. Unlike humans, naked mole rats have an active mechanism for cell division, called telomerase. Developing human cells divide using the same mechanism, but the mechanism is switched off in mature cells, likely to avoid cancer. Vera Gorbunova, who led the study, believes that because naked mole rats can inhibit cancerous cell division, the mechanism doesn't need to be switched off in mole rat cells as it does in human cells. This may grant a longer lifespan to naked mole rat stem cells, aiding in the repair and upkeep of their tissues.

We're still a long ways away from harnessing the naked mole rat's powers for human health, but Gorbunova believes that further study of unusual mammals, like the naked mole rat, will open up more doors than confining our medical studies to rats and mice.

The Life Span of a Rodent May Aid Human Health [NY Times]

According to a release on Lightfoot's work:

"Can you be born a couch potato? In exercise physiology, we didn't used to think so, but now I would say most definitely you can," said Lightfoot.

Of course, loungers don't get off the hook entirely — Lightfoot's study showed that only half the difference between highly active mice and lazier mice could be attributed to their genetics. So an animal's environment — in people's case, whether they live in a 4-story walk up, or dig ditches for a living — is going to have a big impact on how active they are. But Lightfoot says the evidence is piling up that there's more to being lazy than we thought.

Subsequent studies have led the team to suspect that genetic differences are having a profound affect on mouse activity levels by causing significant differences in their brains.

"More and more what we are seeing is differences in brain chemistry. We are really convinced now that the difference is in the brain," Lightfoot said. "There is a drive to be more active."

I love science.

Source: EurekAlert