Cancerless rodent has genetic defense

ROCHESTER, N.Y., Oct. 28 (UPI) -- U.S. scientists say they've discovered how the naked mole rat -- the only known animal that never develops cancer -- defends itself against tumor development.

The rodent, also known as a sand puppy, has a 30-year lifespan that allows ample time for cells to grow cancerous. But scientists say the animal has never been found with tumors of any kind -- and now University of Rochester biologists think they know why.

In a study led by Associate Professor Vera Gorbunova, researchers found the mole rat's cells express a gene called p16 that stops the proliferation of the rodent's cells when too many of them crowd together, thereby stopping runaway growth before it can start.

The researchers said the effect of p16 is so pronounced that when scientists mutated the cells to induce a tumor, the cells' growth barely changed, whereas regular mouse cells became fully cancerous.

"We think we've found the reason these mole rats don't get cancer, and it's a bit of a surprise," Gorbunova said. "It's very early to speculate about the implications, but if the effect of p16 can be simulated in humans we might have a way to halt cancer before it starts."

The research was reported in the Proceedings of the National Academy of Sciences.