Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

'Guardian of the genome' protein found to underlie skin tanning

12.03.2007
May also influence human fondness for sunshine

A protein known as the "master watchman of the genome" for its ability to guard against cancer-causing DNA damage has been found to provide an entirely different level of cancer protection: By prompting the skin to tan in response to ultraviolet light from the sun, it deters the development of melanoma skin cancer, the fastest-increasing form of cancer in the world.

In a study in the March 9 issue of the journal Cell, researchers at Dana-Farber Cancer Institute report that the protein, p53, is not only linked to skin tanning, but also may play a role in people's seemingly universal desire to be in the sun – an activity that, by promoting tanning, can reduce one's risk of melanoma.

"The number one risk factor for melanoma is an inability to tan; people who tan easily or have dark pigmentation are far less likely to develop the disease," says the study's senior author, David E. Fisher, MD, PhD, director of the Melanoma Program at Dana-Farber and a professor in pediatrics at Children's Hospital Boston. "This study suggests that p53, one of the best-known tumor-suppressor proteins in our body, has a powerful role in protecting us against sun damage in the skin."

... more about:
»Fisher »Keratinocytes »POMC »alpha-MSH »p53

In a study published last year, Fisher and his colleagues found that ultraviolet (UV) radiation from the sun causes skin cells called keratinocytes to make and secrete a hormone called alpha-MSH, which attaches to nearby skin cells called melanocytes and spurs them to produce skin-darkening pigment called melanin. The chain of events within keratinocytes that leads to alpha-MSH production, however, was a mystery.

Investigators knew that alpha-MSH is created when another protein, known as pro-opiomelanocortin (or POMC), is split apart. They also knew that the amount of POMC within cells rises sharply when they're exposed to UV rays. But they didn't know what caused the POMC to increase.

One possibility was p53. When Fisher and his colleagues examined the section of the gene for POMC that promotes production of the protein, they found it meshed nicely with p53 – suggesting that when p53 docks there, it revs up POMC production. Additional evidence came when the researchers exposed human and mouse keratinocytes to UV radiation: After six hours, levels of both POMC and p53 were far higher than normal, and the level of pigment-stimulating alpha-MSH was 30 times above normal.

Further experiments clinched the case for p53's role in tanning. When researchers inserted p53 into keratinocytes, POMC levels rose dramatically. When they delivered UV radiation to mice whose keratinocytes lacked p53, POMC production was not induced and the mice did not tan.

The implications of the research go beyond tanning. A common skin condition, especially among the elderly, is the development of small, dark spots that are unrelated to sun exposure. The spots arise when groups of cells begin producing pigment in response to repeated stress or irritation of the skin. Although not dangerous, the condition can be a cosmetic problem, depending on its location.

"Our research offers a potential explanation of how this condition – known as post-inflammatory hyperpigmentation, or age spots – occurs," Fisher says. "We know that it occurs as a result of stress, and p53 is a classic 'stress' protein, going into action when cells experience stress-related DNA damage. What we've learned about p53 suggests that it may trigger the hyperpigmentation process."

There is even the possibility that p53 protects against skin damage in a second – and previously unsuspected – way. The protein not only causes skin to tan in response to sunlight, it may also underlie people's desire to spend time in the sun.

The same process that causes POMC to produce alpha-MSH also leads to the production of b-endorphin, a protein that binds to the body's opiate receptors and may be associated with feelings of pleasure. "Even as p53 is causing skin to tan during sunlight exposure, it may also affect neuronal circuits," Fisher says. "These proteins may provide an explicit link between the regulation of tanning and of mood. It raises the question of whether p53-mediated induction of beta-endorphin is involved in sun-seeking behavior, which often increases skin cancer risk."

Teresa Herbert | EurekAlert!
Further information:
http://www.dana-farber.org

Further reports about: Fisher Keratinocytes POMC alpha-MSH p53

More articles from Life Sciences:

nachricht Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University

nachricht Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017
25.04.2017 | Laser Zentrum Hannover e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

NASA's Fermi catches gamma-ray flashes from tropical storms

25.04.2017 | Physics and Astronomy

Researchers invent process to make sustainable rubber, plastics

25.04.2017 | Materials Sciences

Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017

25.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>