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Science
2015 Feb 20;3476224:842-7. doi: 10.1126/science.1256022.
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Photochemistry. Chemiexcitation of melanin derivatives induces DNA photoproducts long after UV exposure.
Premi S
,
Wallisch S
,
Mano CM
,
Weiner AB
,
Bacchiocchi A
,
Wakamatsu K
,
Bechara EJ
,
Halaban R
,
Douki T
,
Brash DE
.
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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.
Adam,
Single-electron-transfer in the reduction of 1,2-dioxetanes by biologically active substrates.
1989, Pubmed
Adam,
Single-electron-transfer in the reduction of 1,2-dioxetanes by biologically active substrates.
1989,
Pubmed
Beecham,
DNA repair in the c-myc proto-oncogene locus: possible involvement in susceptibility or resistance to plasmacytoma induction in BALB/c mice.
1991,
Pubmed
Brash,
Photoproduct frequency is not the major determinant of UV base substitution hot spots or cold spots in human cells.
1987,
Pubmed
Chedekel,
Photodestruction of pheomelanin: role of oxygen.
1978,
Pubmed
Douki,
Bipyrimidine photoproducts rather than oxidative lesions are the main type of DNA damage involved in the genotoxic effect of solar UVA radiation.
2003,
Pubmed
Gordon-Thomson,
1α,25 dihydroxyvitamin D3 enhances cellular defences against UV-induced oxidative and other forms of DNA damage in skin.
2012,
Pubmed
Halaban,
Endoplasmic reticulum retention is a common defect associated with tyrosinase-negative albinism.
2000,
Pubmed
Hatta,
Melanin monomers within coated vesicles and premelanosomes in melanin synthesizing cells.
1988,
Pubmed
Hochberg,
Role of antioxidants in prevention of pyrimidine dimer formation in UVB irradiated human HaCaT keratinocytes.
2006,
Pubmed
Kayatz,
Oxidation causes melanin fluorescence.
2001,
Pubmed
Knudsen,
Chemiluminescent aldehyde and beta-diketone reactions promoted by peroxynitrite.
2000,
Pubmed
Kollias,
Photoprotection by melanin.
1991,
Pubmed
Kraemer,
Genetic heterogeneity in xeroderma pigmentosum: complementation groups and their relationship to DNA repair rates.
1975,
Pubmed
Krauthammer,
Exome sequencing identifies recurrent somatic RAC1 mutations in melanoma.
2012,
Pubmed
Lamola,
Production of pyrimidine dimers in DNA in the dark.
1971,
Pubmed
Lazovich,
Indoor tanning and risk of melanoma: a case-control study in a highly exposed population.
2010,
Pubmed
Meredith,
The physical and chemical properties of eumelanin.
2006,
Pubmed
Mitra,
An ultraviolet-radiation-independent pathway to melanoma carcinogenesis in the red hair/fair skin background.
2012,
Pubmed
Munoz-Munoz,
Generation of hydrogen peroxide in the melanin biosynthesis pathway.
2009,
Pubmed
Noonan,
Melanoma induction by ultraviolet A but not ultraviolet B radiation requires melanin pigment.
2012,
Pubmed
Roméro-Graillet,
Ultraviolet B radiation acts through the nitric oxide and cGMP signal transduction pathway to stimulate melanogenesis in human melanocytes.
1996,
Pubmed
Schreier,
Thymine dimerization in DNA is an ultrafast photoreaction.
2007,
Pubmed
Slawinska,
Electronically excited molecules in the formation and degradation of melanins.
1982,
Pubmed
Takeuchi,
Melanin acts as a potent UVB photosensitizer to cause an atypical mode of cell death in murine skin.
2004,
Pubmed
Valencia,
Nox1-based NADPH oxidase is the major source of UVA-induced reactive oxygen species in human keratinocytes.
2008,
Pubmed
Velosa,
1,3-diene probes for detection of triplet carbonyls in biological systems.
2007,
Pubmed
Wakamatsu,
UVA-induced oxidative degradation of melanins: fission of indole moiety in eumelanin and conversion to benzothiazole moiety in pheomelanin.
2012,
Pubmed
Williams,
Melanocortin 1 receptor and risk of cutaneous melanoma: a meta-analysis and estimates of population burden.
2011,
Pubmed
Ye,
Photoionization thresholds of melanins obtained from free electron laser-photoelectron emission microscopy, femtosecond transient absorption spectroscopy and electron paramagnetic resonance measurements of oxygen photoconsumption.
2006,
Pubmed
