Tag Archives: mole rat

These animals don’t get cancer, and this might help us obtain a cutre

In the fight with cancer, we need any piece of help we can get. With this in mind, a group of researchers set out to investigate the animals that don’t get cancer (or rarely do) – especially elephants and naked mole rats.

Image via Wikipedia.

 

At a first glance, it seems strange that elephants don’t get cancer. After all, cancer is basically a mutation of a group of cells, and elephants have way more cells than humans, but on average, only 1 in 20 elephants get cancer, compared to 1 in 5 for humans. In fact, there doesn’t seem to be a correlation between cancer occurrence and the number of cells, otherwise bigger animals would get cancer more often, and this doesn’t happen. So why are elephants special?

A team of researchers in the US looked closer and found an abundance of a gene called TP53 which they believe is important for cancer. The gene has been documented and is known for its ability to repair damaged DNA and thus halt the spread of cancer. Humans also have it, but elephants have it 20 times more; it’s an interesting correlation, although likely to be only one piece of the puzzle.

“These findings, if replicated, could represent an evolutionary-based approach for understanding mechanisms related to cancer suppression,” says the report, published in the Journal of the American Medical Association.

These strange mole rats are immune to cancer. Image via Flickr.

Naked mole rats are even more surprising: they never develop cancer, even when researchers try to induce it in a lab. Their natural mechanisms are just good at fighting cancer, at least according to a recent study. These natural mechanisms include a polymer called hyaluronan; the thickness of this polymer controls a number of cell parameters, including cell growth and mechanical strength. Researchers had a hunch this polymer was preventing the spread of cancer, so they eliminated it – and then the cancer spread as it does in other organisms – which seems to indicate that hyaluronan is crucial for fighting cancer.

“We speculate that naked mole rats have evolved a higher concentration of hyaluronan in the skin to provide skin elasticity needed for life in underground tunnels,” reads the separate report, published in Nature. “This trait may have then been co-opted to provide cancer resistance and longevity to this species.”

It’s a long shot, and it’s not yet known if this can work in humans, but studying animals that do well against cancer definitely seems like a good idea. It’s a big biological jump, but it’s definitely worth the effort.

 

The mole rat is unique among the mammal world because of its ability to grow multiple sets of teeth, much in the same manner sharks do. Their teeth aren't that petrifying, though.

The mole rat grows teeth similar to sharks

The mole rat is unique among the mammal world because of its ability to grow multiple sets of teeth, much in the same manner sharks do. Their teeth aren't that petrifying, though.

The mole rat is unique among the mammal world because of its ability to grow multiple sets of teeth, much in the same manner sharks do. Their teeth aren't that petrifying, though.

Humans, as well as most mammals, have only two sets of teeth to make with during their entire lifetime. However, a new research published in the journal Proceedings of the National Academy of Sciences, which studied the dental structure of mole rats has shown that the species is an exception to this rule. In fact, they’re very much similar to sharks, which grow a new set of teeth regularly and change them like a conveyor belt.

In 1957, Stuart Landry first observed that the mole rat had more molars than the average rodent, however this particular fact never interested anyone enough to study the matter further – until now that is, after Helder Gomes Rodrigues from the University of Lyon made this remarkable discovery.

Apart from the mole rat, there are only four other mammals capable of changing their teeth regularly, namely three different manatee species and a pygmy-rock wallaby. Still, the mole rat is unique among mammals, in terms that it has a peculiar up and down movement of its teeth with concomitant rows of teeth sprouting. The other multiple tooth generating mammals first loose their old teeth and then grow a new set, similar to how regular mammals grow a new set after they lose their baby teeth.

X-ray synchrotron microtomographic 3D rendering of the upper dentition of a young mole rat. (c) PNAS

X-ray synchrotron microtomographic 3D rendering of the upper dentition of a young mole rat. (c) PNAS

For his research, Rodrigues analyzed 55 specimens and observed that in each one the back molars in the jaw of the rodents move forward, this although the old one hadn’t come out yet. The researchers saw that by the time the new molars finally reached the first ray, they displayed a very eroded structure from all the wear and tear.

The scientists then sought to find an explanation to this peculiar exception. The manatees and pygmy-rock wallaby have earned the ability to replace their teeth due to the hard elements in their die, however this is not the case with your typical soft plants eating mole rat. Instead, a viable evolutionary explination the researchers have come up with is that their unique ability is due to the fact they primarily dig with their front incisors, they grind things with their molars and swallow abrasive dust.

source