Survival of Cloudman Mouse Melanoma Cells After Irradiation by Solar Wavelengths of Light

Cieszka, Krystyna; Hill, Helene Z.; Xin, Patrick; Azure, Michael; Hill, George J.; Meyenhofer, Markus F.; Boissy, Raymond E.; Mitchell, David L.

doi:10.1111/j.1600-0749.1997.tb00484.x

Cited by 6 publications

(8 citation statements)

References 38 publications

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“…The more heavily pigmented cells (S91/I3) contained 3 pg/cell of melanin and the lightly pigmented cells (S91/amel) contained 1 pg/cell. The more pigmented cells were considerably more sensitive to killing by UVB and UVA, but were less sensitive to killing by the polychromatic FS20 radiation (10). S91/mel contains 1.5 pg/cell of melanin, and is also less sensitive to killing by the three lamps compared to S91/I3 1 .…”

Section: Studies With Pigmented Mouse Cellsmentioning

confidence: 87%

UVA, Pheomelanin and the Carcinogenesis of Melanoma

Hill

2000

Pigment Cell Research

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Cloudman S91 mouse melanoma cells vary in constitutive and inducible melanin levels. Survival, mutation induction and DNA damage were quantitated after exposure to UVB, UVA and FS20 lamps. Assuming that the observed differences are related to melanin, induced pigment is photo-protective for survival and mutation after UVB and FS20 exposure, and is photosensitizing for survival after UVA exposure. No changes in pyrimidine dimers could be measured. DNA damage in pigmented mouse melanocytes (melan-a and melan-b) was greater than that in albino melanocytes (melan-c) after UVB and FS20, and the pigmented cells were more sensitive to killing. Pigment appears to be protective for killing by UVA in these melanocytes. Human melanocytes from different skin types vary in both melanin amount and composition (eu- and pheomelanin). Effects of pigmentation on UVB responses are unclear. In UVA, heavily pigmented cells have more DNA damage than lightly pigmented cells, but are resistant to killing. Increased pheomelanin photosensitizes DNA damage in lightly pigmented cells. Since eumelanin predominates in the mouse melanoma cells and melanocytes, they are less likely than human cells to provide a satisfactory model for human solar melanomagenesis. In order to understand the mechanism of photocarcinogenesis of melanoma, melanins in human melanocytes from different pigment types should be carefully quantitated and characterized. Mutations induced in them by solar wavelength-emitting lamps with well-characterized spectra should be measured, and mutant DNA should be sequenced to determine the nature of the solar-induced lesions. Research should focus on UVA and pheomelanin.

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Section: Studies With Pigmented Mouse Cellsmentioning

confidence: 87%

UVA, Pheomelanin and the Carcinogenesis of Melanoma

Hill

2000

Pigment Cell Research

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“…It has been reported that more highly melanotic cell lines in tissue culture are not always protected more efficiently by melanin than are less melanotic cell lines against UV induced DNA photoproducts (Chalmers et al, 1976;Hill and Setlow, 1980;Huselton and Hill, 1990;Niggli, 1990;Schothorst et al, 1991;Yohn et al, 1992;Cieszka et al, 1997). This may result from the fact that only a small amount of melanin can be located over the nucleus because of the flattened morphology of cells in culture, and dispersed intracellular melanin cannot protect against DNA photoproduct formation as efficiently as supranuclear melanin caps observed in human epidermis in vivo (Kobayashi et al, 1993).…”

Section: Discussionmentioning

confidence: 99%

Supranuclear Melanin Caps Reduce Ultraviolet Induced DNA Photoproducts in Human Epidermis

Kobayashi

Nakagawa

Muramatsu

et al. 1998

Journal of Investigative Dermatology

215

169

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Melanin can form supranuclear caps in human epidermis, suggesting that intracellular melanin reduces ultraviolet transmission to underlying cell nuclei and inhibits the formation of ultraviolet induced DNA photoproducts. The purpose of this study was to determine the photoprotective effect of epidermal melanin. We irradiated normal human skin explants with ultraviolet B and determined the formation of cyclobutane pyrimidine dimers and (6-4)photoproducts in individual epidermal cells by indirect immunofluorescence and by laser cytometry using monoclonal antibodies specific for cyclobutane dimers or for (6-4)photoproducts. We found that epidermal cells with supranuclear melanin caps had significantly less DNA photoproducts (both types) than epidermal cells without supranuclear melanin caps. Moreover, the protection factor against both types of photolesions correlated with melanin concentration in epidermal cells. These results indicate that melanin reduces ultraviolet induced DNA photoproducts in human epidermis in a concentration dependent manner.

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“…Based on these absorbance spectra, leucophores and melanophores should provide the most ultraviolet (UV) pho-Key words: Melanin, Pteridines, Photoprotection, Carote-toprotection to fish since the compounds they contain, ptenoids, Pigment cells, Fish ridines and melanin, correspondingly, have strong absorcaused complete mortality in cultured pigment cells lacking melanin (5). A more highly pigmented variant of a Cloudman mouse melanoma cell line was more resistant to cell killing than a lightly pigmented variant of the same type of cells when exposed to broadband ultraviolet light (8).…”

Section: Bances In the Uv Region Of The Spectrum Xanthophoresmentioning

confidence: 99%

Microspectrophotometric Analysis of Intact Chromatophores of the Japanese Medaka, Oryzias latipes

Armstrong

Cronin

Bradley

2000

Pigment Cell Research

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To investigate the possible photoprotective role of chromatophores in fish, the absorbances of four types of intact chromatophores in adult and larval Japanese medaka were analyzed using microspectrophotometric techniques. The absorbance spectrum of each chromatophore class was obtained from 300 to 550 nm. The absorbance spectra of intact leucophores, melanophores and xanthophores were very similar to the published absorbance spectra of the isolated pure pigments contained in each chromatophore type, pteridines, melanin and carotenoids or pteridines, respectively. Based on these absorbance spectra, leucophores and melanophores should provide the most ultraviolet (UV) photoprotection to fish since the compounds they contain, pteridines and melanin, correspondingly, have strong absorbances in the UV region of the spectrum. Xanthophores containing carotenoids are not likely to provide much protection to fish from UV-induced damage since carotenoids have low absorbances in the UV range. Xanthophores containing colored pteridines, however, may provide somewhat greater UV protection to fish, since pteridines absorb more light than carotenoids in the UV portion of the spectrum. The relative frequency, coverage and thickness of these two types of xanthophores should determine how much protection xanthophores as a chromatophore type would provide against UV-induced damage.

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Survival of Cloudman Mouse Melanoma Cells After Irradiation by Solar Wavelengths of Light

Cited by 6 publications

References 38 publications

UVA, Pheomelanin and the Carcinogenesis of Melanoma

UVA, Pheomelanin and the Carcinogenesis of Melanoma

Supranuclear Melanin Caps Reduce Ultraviolet Induced DNA Photoproducts in Human Epidermis

Microspectrophotometric Analysis of Intact Chromatophores of the Japanese Medaka, Oryzias latipes

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