Featured Research

from universities, journals, and other organizations

Study May Help Explain Sunlight's Role In Melanoma Development, Have Screening Implications

Date:
February 24, 2003
Source:
University Of North Carolina School Of Medicine
Summary:
A strong link exists between lifetime exposure to ultraviolet light, particularly lifetime sunburns, and the development of melanoma - the most lethal form of skin cancer. Now, for the first time, scientists have identified a specific molecular pathway within cells that becomes mutated by ultraviolet light exposure, thereby speeding up melanoma development.

CHAPEL HILL -- A strong link exists between lifetime exposure to ultraviolet light, particularly lifetime sunburns, and the development of melanoma - the most lethal form of skin cancer.

Related Articles


Now, for the first time, scientists have identified a specific molecular pathway within cells that becomes mutated by ultraviolet light exposure, thereby speeding up melanoma development.

New findings published in the Feb. 4 issue of Proceedings of the National Academy of Sciences may have implications for screening people at high risk, including those "with a significant history of sunburn and suspicious skin moles," said study co-author, Dr. Norman Sharpless, assistant professor of medicine and genetics at the University of North Carolina at Chapel Hill School of Medicine and a member of UNC's Lineberger Comprehensive Cancer Center.

"Who hasn't been sunburned?" he said. "This work suggests a rational method for risk stratification, for screening questionable skin moles - atypical nevi - for specific molecular lesions."

In the new study, Sharpless and colleagues at Harvard Medical School used mice deficient in an important tumor suppressor protein connected to the "anti-cancer" cell signaling pathway ARF-p53. In addition to this deficiency, these mice were genetically designed to produce another protein, H-Ras, in their pigmented skin cells, or melanocytes.

"Loss of ARF-p53 and activation of Ras are two of three hallmark events detected in human melanomas. The third being loss in another 'anti-cancer' cell signaling pathway, p16INK4a-Rb," said Sharpless.

This mouse model allowed researchers to selectively test the effects of ultraviolet light exposure on the p16INK4a-Rb pathway.

The Rb pathway regulates cell growth. The retinoblastoma protein acts to hold cell proliferation in check. The regulatory capacity of Rb is moderated by CDK6 and the tumor suppressor protein, p16INK4a.

In this work, the authors showed that ultraviolet light exposure accelerated melanoma formation on the treated mice compared with melanomas arising spontaneously in the absence of such exposure. The researchers found targeting of the Rb pathway, either by an increase in CDK6 expression or a loss of p16INK4a, in the melanomas that developed on mice treated with a single exposure of ultraviolet light - essentially, a mouse sunburn. In mice genetically engineered to lack p16INK4a, however, ultraviolet light exposure did not increase melanoma formation.

"These data suggest that it is not so much this gene or that gene, but the pathway that is what UV light targets," Sharpless said.

"This is one of the better mouse models for any human tumor that I'm aware of," he added. "This finding is unique in that it identifies the Rb pathway as a target of UV's mutagenic action."

The next research step is to look at a collection of clinical samples to determine if exclusive lesions in the Rb pathway are linked to melanomas from patients with a detailed history of ultraviolet light exposure.

"Melanoma screening is a good idea, but it needs some molecular help to distinguish the really high-risk patients from those at a lower risk for developing melanoma," Sharpless said. "This would be a way to deal with this very large clinically heterogeneous population of patients at risk."

###

The Howard Hughes Medical Institute and the National Institutes of Health provided funding for the research.


Story Source:

The above story is based on materials provided by University Of North Carolina School Of Medicine. Note: Materials may be edited for content and length.


Cite This Page:

University Of North Carolina School Of Medicine. "Study May Help Explain Sunlight's Role In Melanoma Development, Have Screening Implications." ScienceDaily. ScienceDaily, 24 February 2003. <www.sciencedaily.com/releases/2003/02/030224081837.htm>.
University Of North Carolina School Of Medicine. (2003, February 24). Study May Help Explain Sunlight's Role In Melanoma Development, Have Screening Implications. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2003/02/030224081837.htm
University Of North Carolina School Of Medicine. "Study May Help Explain Sunlight's Role In Melanoma Development, Have Screening Implications." ScienceDaily. www.sciencedaily.com/releases/2003/02/030224081837.htm (accessed October 25, 2014).

Share This



More Health & Medicine News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
WHO: Millions of Ebola Vaccine Doses by 2015

WHO: Millions of Ebola Vaccine Doses by 2015

AP (Oct. 24, 2014) The World Health Organization said on Friday that millions of doses of two experimental Ebola vaccines could be ready for use in 2015 and five more experimental vaccines would start being tested in March. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Doctor in NYC Quarantined With Ebola

Doctor in NYC Quarantined With Ebola

AP (Oct. 24, 2014) An emergency room doctor who recently returned to the city after treating Ebola patients in West Africa has tested positive for the virus. He's quarantined in a hospital. (Oct. 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins