Naked Mole Rat Genome Map May Aid in Cancer, Aging Research

The naked mole rat, a hairless African rodent with a long life-span and resistance to tumors, may hold clues to countering cancer and age-related ailments in people, said scientists who have mapped the creature’s genome.

A first analysis of the naked mole rat’s genome has already revealed insights into its longevity, and that it split from its mice and rat cousins about 73 million years ago, according to the research published today in the journal Nature.

The naked mole rat lives 10 times longer than mice, or more than 30 years. While 95 percent of mice die from cancer, the naked mole rat is impervious to the disease, said Andrei Seluanov, a researcher at the University of Rochester. These traits offer scientists new opportunities to understand certain biological processes, the researchers wrote.

“It’s an unusual animal with several very interesting features: a long lifespan, resistance to cancer, and its social structure,” said study author Vadim Gladyshev, a Harvard Medical School professor and the director of redox medicine at Brigham & Women’s Hospital in Boston. “We want to compare the naked mole rat with other mammals to find more general themes and traits that may be consistent with a long lifespan.”

Because 93 percent of mouse genes are similar to naked mole rat genes, the sequenced genome may enable scientists to transfer naked mole rat genes into mice, to see where the cancer benefits are, said Seluanov, who wasn’t affiliated with the study, in a telephone interview.

Alzheimer’s Clue

When the scientists sequenced brain samples from a newborn, a 4-year-old and a 20-year-old naked mole rat, they found few variations in activation based on age. That’s unusual in mammals; humans underexpress 33 genes and overexpress 21 when they age.

One gene that’s muted in the human brain and amplified in the naked mole rat’s brain influenced the clumping of beta amyloid, the characteristic protein in Alzheimer’s disease. Another made it difficult for cells to proliferate, limiting cancer risk in the rodents. The different activation patterns may explain the animal’s unusual longevity, the scientists wrote.

The journal also published a paper on the genetic sequencing and comparative analysis of 29 other mammalian genomes, including humans, chimpanzees, mice and dogs. About 4 percent of the human genome consists of sequences preserved throughout these animals.