"For the first time, UVA rays have been shown to cause significant damage to the DNA of human melanocyte skin cells," says Moon-shong Tang, PhD, professor of environmental medicine, pathology and medicine at NYU School of Medicine. "And because melanocytes have a reduced capacity to repair DNA damage from UVA radiation, they mutate more frequently, potentially leading to the development of melanoma."
In this study, researchers exposed lightly and darkly pigmented human melanocytes to UVA radiation and assessed DNA damage and the capacity of these cells to repair damaged DNA. DNA damage was detected in all melanocyte cells and these cells were unable to repair the damage. Normal skin cells were also exposed to UVA light but no damage to their DNA was observed.
"Identifying the underlying causes of melanoma allows researchers to develop new ways to assess a person's risk of melanoma, prevent the disease and aid in the design of more effective treatments," said Dr. Tang, who is also a member of the NYU Cancer Institute.
Sunlight in the form of UVA radiation causes oxygen in melanocytes to damage DNA. Thus, oxidative DNA damage adversely affects transcription and DNA replication in melanocytes. The authors concluded that UVA-induced oxidative DNA damage in melanocytes and the inherently reduced repair capacity in these cells are the two key factors that contribute to melanoma on the skin.
The authors also discovered the underlying mechanism to explain why melanoma can also develop in areas never exposed to sunlight: Because melanocytes generally have a limited capacity to repair any DNA damage, they have a higher mutation frequency rate and are more susceptible to the development of melanoma—even without the effects of the sun.
"Melanoma, the deadliest form of skin cancer, continues to increase at a rate of 3 percent a year," says Dr. Tang. "This research highlights the necessity of limiting UVA radiation by avoiding excessive sunlight, tanning and sunbeds."
The study received funding from the National Institutes of Health in Bethesda, Maryland. It was published early online and will be appear in the print edition of the Proceedings of the National Academy of Sciences on July 6, 2010.
About NYU Langone Medical Center
NYU Langone Medical Center is one of the nation's premier centers of excellence in healthcare, biomedical research, and medical education. For over 170 years, NYU physicians and researchers have made countless contributions to the practice and science of health care. Today the Medical Center consists of NYU School of Medicine, including the Smilow Research Center, the Skirball Institute of Biomolecular Medicine, and the Sackler Institute of Graduate Biomedical Sciences; and the NYU Hospitals Center, including Tisch Hospital, a 705-bed acute-care general hospital, Rusk Institute of Rehabilitation Medicine, the first and largest facility of its kind, and NYU Hospital for Joint Diseases, a leader in musculoskeletal care, a Clinical Cancer Center and numerous ambulatory sites.
Lauren Woods | EurekAlert!
Signaling Pathways to the Nucleus
19.03.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau
In monogamous species, a compatible partner is more important than an ornamented one
19.03.2018 | Max-Planck-Institut für Ornithologie
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
19.03.2018 | Physics and Astronomy
19.03.2018 | Materials Sciences
19.03.2018 | Event News