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 Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Topological Quantum Chemistry
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>