Chemiexcitation of melanin derivatives induces DNA photoproducts long after UV exposure
| Autor: | Silvia Wallisch, Thierry Douki, Camila Marinho Mano, Etelvino J. H. Bechara, Kazumasa Wakamatsu, Ruth Halaban, Douglas E. Brash, Adam B. Weiner, Sanjay Premi, Antonella Bacchiocchi |
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| Přispěvatelé: | Yale University School of Medicine, Sch Hlth Sci, Dept Chem, Fujita Hlth Univ, Universidade de São Paulo (USP), Department of Dermatology, Laboratoire Lésions des Acides Nucléiques (LAN), Service de Chimie Inorganique et Biologique (SCIB - UMR E3), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)-Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), Yale School of Medicine [New Haven, Connecticut] (YSM), Universidade de São Paulo = University of São Paulo (USP) |
| Rok vydání: | 2015 |
| Předmět: |
Keratinocytes
DNA damage Pyrimidine dimer MELANOMA Biology Photochemistry medicine.disease_cause Melanin 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine medicine Pheomelanin 030304 developmental biology Ultraviolet Skin [PHYS]Physics [physics] 0303 health sciences Multidisciplinary Mutagenesis 3. Good health Thymine chemistry 030220 oncology & carcinogenesis sense organs Cytosine DNA |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP Science Science, American Association for the Advancement of Science, 2015, 347 (6224), pp.842-847. ⟨10.1126/science.1256022⟩ Science, 2015, 347 (6224), pp.842-847. ⟨10.1126/science.1256022⟩ |
| ISSN: | 0036-8075 1095-9203 |
| Popis: | International audience; Mutations in sunlight-induced melanoma arise from cyclobutane pyrimidine dimers (CPDs), DNA photoproducts that are typically created picoseconds after an ultraviolet (UV) photon is absorbed at thymine or cytosine. We found that in melanocytes, CPDs are generated for > 3 hours after exposure to UVA, a major component of the radiation in sunlight and in tanning beds. These "dark CPDs" constitute the majority of CPDs and include the cytosine-containing CPDs that initiate UV-signature C -> T mutations. Dark CPDs arise when UV-induced reactive oxygen and nitrogen species combine to excite an electron in fragments of the pigment melanin. This creates a quantum triplet state that has the energy of a UV photon but induces CPDs by energy transfer to DNA in a radiation-independent manner. Melanin may thus be carcinogenic as well as protective against cancer. These findings also validate the long-standing suggestion that chemically generated excited electronic states are relevant to mammalian biology. |
| Databáze: | OpenAIRE |
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