Why the nude human is immune to cancer

Researchers decipher the body's own cancer protection of the nacktmulle

20/06/2013

Nacktmullen have a body's own cancer protection. US scientists from the Institute of Biology at the University of Rochester and the Havard School of Public Health have now teamed up with Israeli and Chinese researchers to determine how the nude people build their unusual resistance to cancer. They hope to use the mechanism for the treatment of cancer in the future.

In the trade magazine „Nature“ The team led by Vera Gorbunova and Andrei Seluanov of Rochester University reports that they have succeeded in deciphering the mechanism that protects nude muggettes from cancer. „We found that nude gland fibroblasts secrete very much high molecular weight hyaluronic acid (HA)“, the researchers write. This has the consequence that the so-called contact inhibition, which slows down further cell growth when the cells come into contact with the neighboring cells, starts much earlier in the nude mice. An uncontrolled cell growth will be avoided in this way.

Naked little man with unusual physical characteristics
Naked little people are a very interesting research object for science because they have a variety of special features. For example, nudibles with a maximum lifespan of more than 30 years exhibit exceptional longevity, especially given their low body mass. „In comparison, a similarly sized house mouse has a maximum lifespan of four years“, write the US researchers. Nacktmulle also come out without sunlight, for which they have developed a special mechanism of vitamin D formation. In addition, the rodents apparently lack any pain sensation.

Naked little people never get cancer
For the research team led by Vera Gorbunova and Andrei Seluanov, the cancer resistance of rodents observed in earlier studies was of particular interest in their current research. In „Multi-year observations of large nudibranch colonies did not detect a single occurrence of cancer“, the researchers write. How Nacktmulle prevents uncontrolled cell growth and thus the formation of tumors has remained unclear. In order to clarify this, the scientists created cell cultures of nude gland fibroblasts (nude gland connective tissue cells) in the laboratory and observed their development. They found that the consistency of the cell cultures differed significantly from those of other rodents. The cell cultures of nude pulp connective tissue cells were stickier and more viscous than those of mice and also as those of humans, the scientists report.

Preventing uncontrolled cell growth in nude mice early
According to the researchers, the reason for the tougher consistency of cell cultures from nude-mouse fibroblasts was a significantly higher proportion of hyaluronic acid, which also showed a molecular weight more than five times greater than that of humans and mice. „This high molecular weight HA mass accumulates abundantly in nude-mollified tissue due to the decreased activity of HA-degrading enzymes and a unique sequence of hyaluronan synthase 2“, Gorbunova and Seluanov report. Hyaluronic acid plays an essential role in the aforementioned contact inhibition. Here it was revealed that the nude mouse cells are also far more sensitive „the HA signaling responded as they had a higher affinity compared to the mouse or human cells“, the US researchers continue. In other words, further cell growth was prevented much earlier.

Hyaluronic acid protects nacktmulle from cancer
In further experiments, the scientists examined whether the protection of the nude mouse from hyaluronic acid was related to reducing their concentration in the cell cultures and then observing how the malignant cell transformations developed. Indeed, they found that without the protection of the increased HA concentration, nude gland connective tissue cells also had malignant changes. Thus it seems clear that the cancer protection of the nacktmulle goes back to the high hyaluronic acid concentration. However, it is unclear why the rodents have such a high proportion of hyaluronic acid in the connective tissue. „We speculate that nude mollusks have developed a higher concentration of HA in the skin to provide the needed elasticity of the skin for living in underground tunnels“, explain the researchers. As a side effect, this property then brought with it cancer resistance and longevity of this kind.

New approach to cancer therapy
If the findings of the research team led by Vera Gorbunova and Andrei Seluanov confirm in further studies, hyaluronic acid could possibly make a significant contribution to cancer treatment or prevention in the future. Another advantage would be that hyaluronic acid is already used for medical purposes and therefore relatively well researched. So far, HA is mainly used in the treatment of osteoarthritis, whereby the active ingredient is injected as a kind of buffer directly into the joint. Hyaluronic acid is also found in some eye drops and nasal sprays. However, the researchers may have discovered the most promising effects of hyaluronic acid only now. (Fp)