The ageless rat touted as a cure for cancer It's no secret that wrinkled, almost hairless rats with teeth sticking out of their mouths, ...

The ageless rat touted as a cure for cancer

It's no secret that wrinkled, almost hairless rats with teeth sticking out of their mouths, naked rats are not the most attractive animals on Earth.

But what these creatures lack in beauty, they make up for in a combination of incredible features that fascinate zoologists and medical researchers around the world.

Despite their small size—ranging from 3 to 13 inches—these mice live an average of 30 years, are resistant to chronic diseases, including diabetes, and have impressive reproductive systems.

Animals also provide environmental benefits by acting as "ecosystem engineers" and enhancing biodiversity on land when they dig holes to make nests.

Now, research shows that they may be the solution in understanding various human problems, including cancer and aging.

Special Benefits

Although we have studied mice to understand the mysteries of human biology, scientists believe that naked mice have special advantages for medical research.

Heterocephalus glaber, the scientific name of the species, which basically means "bald thing with a different head," is native to the tropics of northeastern Africa.

In the wild, they live in large underground areas that can reach up to 300, with a density of tunnels and chambers the length of several football fields.

The harsh and low-oxygen conditions in which the naked mouse lives may be a clue to some of the unusual behaviors of this species.

Most aerobic organisms have a hard time surviving in such a low oxygen environment, however the naked mouse is the longest living mouse.

A mouse of the same size can live for two years, compared to 30 years or more for a naked mouse. If we scale that ratio down to our size, say, it would be as if humans had a shriveled cousin who could live 450 years.

Found in the wild in Kenya, Ethiopia, and Somalia, naked rats live in colonies of about 70 to 80 members, with some harboring up to 300 animals.

These colonies are ruled by queens and follow strict leadership. Members manage various tasks, such as collecting underground parts of plants, such as bulbs, roots, , which they eat along with excrement.

The biology of this species is very unique. Naked rats are considered "extreme animals" because they can thrive in extreme subterranean environments, says Ewan St John Smith, a neuroscientist at the University of Cambridge in England.

One of their unique characteristics is that it is difficult to tell exactly the age of naked mice, as they show few signs of physical deterioration.

While humans may continue to wrinkle, go gray, or become more susceptible to chronic diseases, "the normal signs of aging that you'd expect to see in most mammals don't seem to occur," says Smith.

Why do they avoid cancer?

Why naked mice avoid cancer is still a mystery. Many hypotheses have been put forward over the years, and scientists are struggling to provide a solid explanation.

According to one theory, nude mice have a well-designed cancer-fighting mechanism called cellular senescence, an evolutionary adaptation that prevents damaged cells from dividing uncontrollably and turning into cancer.

Another theory suggests that naked mice make "super sugar" that prevents cells from clumping together and forming tumors.

The latest research focuses on a unique condition in their bodies that prevents cancer cells from multiplying.

Experts from the University of Cambridge suggest that the interaction with the microenvironment of naked mice, a complex system of cells and molecules surrounding the cells, including the immune system, prevents disease, rather than the natural anti-cancer mechanism.

Perhaps the most amazing thing about the naked mouse is that it cannot tolerate pain. "Maybe this is the result of evolution to adapt to [their] carbon dioxide environment," explains Smith.

Gisela Helfer, a professor of physiology and metabolism at the University of Bradford in England, says the naked mouse is also a "perfect model" for studying human puberty.

Along with the wild mouse of Damaraland, the naked mouse is one of two examples of mammals that live in groups of alternating generations where only one female is responsible for reproduction and the others work together to care for the young.

The Reigning Queen

Like bees, the queen of high rank rules a colony of naked mice, breeding with one to three males at a time.

Others have different roles, such as workers who dig holes in the colony with their feather-like teeth and search for food, providing the queen with roots and bulbs to eat.

Typically, there is only one fertile pair per herd, and some animals never reach puberty, Helfer explains. However, if a naked rat is removed from its colony, it will quickly begin releasing sex hormones and the animal will reach puberty.

"Humans have a long pre-puberty period of about eight to 12 years," he notes. "When a boy enters puberty, hormones are activated in the brain, causing the production of sex hormones and allowing the reproductive tract to mature."

This reflects the development of puberty among naked mice when subordinate females are separated from the queen (dominant female) in the herd.

In contrast, mice go through puberty very quickly, within two weeks of birth, making them poor models for studying sex hormones.

Rats also have unique ways of communicating with each other, deciding who is friend or foe through different dialects, just like humans.

They usually convey information unique to an animal's group, and one study suggests that it is learned culturally, rather than genetically.

The noises are often related to the queen, with the hatchlings taking up the height of the colony that raised them, which can change if the queen is replaced.

One study records 18 different calls including alarm calls, food gathering sounds, mating sounds, toileting sounds.

When predators are nearby, several different alarm sounds are used to defend the colony.

Another way in which naked rats cooperate as a colony is through sustainable agriculture.

Meals include bringing large roots such as sweet potatoes into the holes, each meal weighing 50 kg, to be chewed by other members of the group.

Naked mice shed the outer layers of the poisonous plant, eat its food, and then cover the areas they ate with dirt, allowing the roots to regenerate and become another food in the future.

Although they are biologically amazing, naked rats are not the easiest species to care for and work with, which means that only a few research groups around the world study this amazing species.

"Although its extreme biology is very interesting and provides great insights, it is not easy for everyone to start their own research center for this species," says Smith.

For this reason, Smith launched the Naked Rat Program, to collaborate with experts in other medical fields, such as cancer, and use their animals to support new lines of research.

If scientists can figure out why these pesky mammals live long and healthy lives, they could "translate" this knowledge into immunotherapy or drugs that treat cancer once it's started, Smith says.

And there may be other benefits to researching these very common animals, some of which would be difficult to predict.