The same molecules that endow naked mole rats with springy, wrinkled skin also seem to prevent the homely rodents from contracting cancer. Research published on Nature's website today identifies a sugary cellular secretion that stops the spread of would-be tumours1. Naked mole rats (Heterocephalus glaber), which are more closely related to porcupines than rats, are freaks of nature. The short-sighted creatures spend their lives in subterranean colonies in the service of a single breeding queen — H. glaber is one of only two 'eusocial' mammals ever discovered. The rodent doesn’t feel the sting of acids or the burn of chilli peppers, and seems to be the only mammal that is unable to regulate its body temperature.
However, the animal's longevity and impunity to cancer are the reason why biologist Andrei Seluanov keeps around 80 naked mole rats in a special facility near his lab at the University of Rochester in New York state. The rodents have been known to live for up to 32 years, and scientists have never seen one with cancer. Mice, by comparison, rarely live past the age of four and do often die of cancer. In 2009, Seluanov’s team reported that the naked mole rat's fibroblasts (a cell type found in connective tissue) are sensitive to the presence of other cells, and in Petri dishes they grow less crowded than mouse fibroblasts do2. To the annoyance of his lab workers, the broth they used to nurture the cells often turned so viscous that it clogged the drains. “Our lab technician was unhappy because she needed to disassemble the system and clean all this gooey stuff,” Seluanov recalls. “I told my graduate student that we have to find out what the gooey substance is — it should be related to their cancer resistance. Of course, at that time it was just a wild guess.” The team soon discovered that the plumbing problem was the result of a sugar called hyaluronic acid (HA). Fibroblasts ooze HA and, along with collagen and other chemicals, it forms the extracellular matrix that gives tissues their shape and makes skin elastic. Naked mole rats, Seluanov’s team discovered, produce large amounts of long chains of HA.