title: Infrared A radiation promotes survival of human melanocytes carrying ultraviolet radiation-induced DNA damage.
abstract: The link between solar radiation and melanoma is still elusive. Although infrared radiation (IR) accounts for over 50% of terrestrial solar energy, its influence on human skin is not well explored. There is increasing evidence that IR influences the expression patterns of several molecules independently of heat. A previous in vivo study revealed that pretreatment with IR might promote the development of UVR-induced non-epithelial skin cancer and possibly of melanoma in mice. To expand on this, the aim of the present study was to evaluate the impact of IR on UVR-induced apoptosis and DNA repair in normal human epidermal melanocytes. The balance between these two effects is a key factor of malignant transformation. Human melanocytes were exposed to physiologic doses of IR and UVR. Compared to cells irradiated with UVR only, simultaneous exposure to IR significantly reduced the apoptotic rate. However, IR did not influence the repair of UVR-induced DNA damage. IR partly reversed the pro-apoptotic effects of UVR via modification of the expression and activity of proteins mainly of the extrinsic apoptotic pathway. In conclusion, IR enhances the survival of melanocytes carrying UVR-induced DNA damage and thereby might contribute to melanomagenesis.
authors: Division of General Dermatology, Department of Dermatology, Medical University of Vienna, Vienna, Austria.
authors: Susanne
authors: S
authors: Kimeswenger
authors: Department of Dermatology, Christian-Albrechts-University Kiel, Kiel, Germany.
authors: Agatha
authors: A
authors: Schwarz
authors: Division of General Dermatology, Department of Dermatology, Medical University of Vienna, Vienna, Austria.
authors: Dagmar
authors: D
authors: Födinger
authors: Department of Dermatology, Christian-Albrechts-University Kiel, Kiel, Germany.
authors: Susanne
authors: S
authors: Müller
authors: Division of General Dermatology, Department of Dermatology, Medical University of Vienna, Vienna, Austria.
authors: Hubert
authors: H
authors: Pehamberger
authors: Department of Dermatology, Christian-Albrechts-University Kiel, Kiel, Germany.
authors: Thomas
authors: T
authors: Schwarz
authors: Division of General Dermatology, Department of Dermatology, Medical University of Vienna, Vienna, Austria.
authors: Christian
authors: C
authors: Jantschitsch
mesh_terms: D017209:Apoptosis / Q000528:radiation effects*; D004249:DNA Damage / Q000528:radiation effects; D006801:Humans; D007231:Infant, Newborn; D007259:Infrared Rays; D008544:Melanocytes / Q000528:radiation effects*; D008545:Melanoma / Q000209:etiology*; D061251:Primary Cell Culture; D014466:Ultraviolet Rays / Q000009:adverse effects*
keywords: DNA damage; apoptosis; infrared radiation; melanocytes; ultraviolet radiation