Do bacteria offer natural protection against skin cancer?
Generally, most people try to avoid contact with germs and bacteria. However, there are also bacteria that have a positive effect on health. Researchers have now found that bacteria found on the skin seem to protect against skin cancer.
The University of California, San Diego scientists found that skin bacteria can help protect against skin cancer. The experts published the results of their study in the English-language journal "Science Advances".
Some bacteria are healthy for humans
Not all bacteria harm humans. There are various examples of this, such as probiotics and healthy intestinal bacteria. A new group of bacteria has now been identified, which seems to have positive effects. These are the common human skin bacteria of the genus Staphylococcus epidermidis. These produce a substance that can prevent the growth of tumors.
Staph bacteria protect mice from cancer
The researchers examined the antimicrobial abilities of staph bacteria. This type of bacteria normally lives on human skin. During their investigation, they found something unexpected. Treating mice with these bacteria resulted in remarkable resistance to skin cancer in the experimental animals, the authors explain.
The compound 6-N-hydroxyaminopurine leads to the protective effect
In further studies, the compound responsible for natural protection, which was produced by the bacteria, could then be identified. It was 6-N-hydroxyaminopurine (HAL-6). Because of the structure of the compound (it resembled the building blocks of DNA), medical professionals wondered whether it could interfere with DNA synthesis. In additional experiments, the researchers were able to determine that the secreted compound actually affects the machinery of DNA synthesis.
HAL-6 prevents cancer cell growth
HAL-6 blocks the enzyme that builds DNA chains and prevents them from growing, the researchers say. This may sound like a negative ability at first, but the connection did not affect normal healthy skin cells. Instead, HAL-6 acted on cancer cells and prevented out of control growth.
Effect of HAL-6 on mice
If the bacterial flora in the mice did not secrete HAL-6, the animals developed skin cancer relatively quickly after exposure to high UV doses. The compound was produced in mice with an intact bacterial flora, which meant that they were protected from cancer after radiation, the scientists explain. The researchers were also able to show that HAL-6 not only has a preventive effect, but also inhibits the growth of tumor cells that have already formed. Cancer-treated mice received HAL-6 every 48 hours, causing the tumors of the animals to become 50 percent smaller within two weeks compared to the tumors in laboratory mice from a control group.
HAL-6 has great potential
The results underline the potential of the microbiome to affect human diseases. Humans seem to have developed a mutually beneficial relationship with this bacterium over time, says study author Richard Gallo from the University of California, San Diego. We may have developed in such a way that we offer the organisms a safe refuge because the bacteria are also useful for humans, the expert suspects.
Compound HAL-6 still worked when isolated from the bacteria - both when injected and when applied topically. This shows their potential for future treatments, which need not only concern skin cancer. The researchers also found that HAL-6 is also effective in reducing lymphoma cell growth rates, so this natural defense could potentially be used for a much broader application.
More research is needed
Of course, more research will be needed to investigate exactly how Staphylococcus epidermidis makes the connection and whether there is any toxic content. Only about 20 percent of the population has these bacteria on their skin, so the researchers have to make sure that they are safe for everyone. The results of the study also remind us that only a very small percentage of the organisms around us are actually harmful and many of them are of benefit to us instead. (as)