Pigmented melanoma

Melanoma A form of skin cancer that arises in melanocytes, the cells that produce pigment. Melanoma usually begins in a mole. [NIH]... 

Ara G, Anderson R,Mandel K, Oseroff AR. Absorption of ns photoradiation of melano-somes generates acoustic waves and induced pigmented melanoma cell toxicity. Photo-chem Photobiol 1988 47 37S-40S. 

Melanoma antigen HMB-45 Neuraminidase-sensitive oligosaccharide side chain of glycoconjugate in immature melanosomes Extract of pigmented melanoma metastases from lymph nodes Dako 1 200 HIER... 

Figure 9.1 Upper panel absorption of blood measured with a spectrophotometer. The blood was sampled from a hairless female BALB/c mouse and diluted in PBS (1 100) immediately before the measurements. Lower panel the penetration depth (8) of light as a function of the wavelength measured in various biological tissues. Human skin excised from an abdominal region of a female patient was provided by Dr. J.F. Evensen. Amelanotic melanoma (LOX) or pigmented melanoma (B16-F10) cells were injected subcutaneously (approximately 1.0 to 2.0-106 cells per mouse) into a flank of a hairless female BALB/c mouse and the tumors were excised after 10 and 20 days, respectively. Measurements in skin in vivo were performed in a living female hairless RWT rat.

Juzenas, P., Juzeniene, A., Stakland, S., Iani, V., and Moan, J. (2002b) Photosensitizing effect of protoporphyrin IX in pigmented melanoma of mice, Biochem. Biophys. Res. Commun., 297 468 -72. 

Light and Toxic Reactions In many individuals, exposure to ultraviolet radiation from the sun causes skin reactions such as erythema, thickening of the epidermis, and darkening of existing pigment. Exposure to ultraviolet light also increases the risk of different forms of skin cancers, especially malignant melanoma. ... 

Melanoma A skin tumor containing dark pigment. 

Riley, P.A., Melanogenesis and melanoma, Pigment Cell Res., 16, 548, 2003. Rorsman, H., The pigmented life of a red hair bibliographic review, Pigment Cell Res., 17, 191, 2004. 

Generally, the phenotype that predisposes an individual to an increased risk of skin cancer is red or blond hair, blue eyes, and fair skin. These characteristics are surrogate measure of the sensitivity of the skin to sun exposure and the tendency to develop nevi, freckles, and sunburns based on the skin type. Freckles, which may appear abruptly after the first high dose of UV radiation sun exposure, represent clones of mutated melanocytes, and their presence is associated with an increased risk of melanoma.12 The Fitzpatrick classification of skin type is used to determine the response pattern of the skin to UV radiation and assess the risk for melanoma. There are six Fitzpatrick skin types Type I skin always burns and never tans, type II skin burns easily and tans rarely, type III skin burns sometimes and tans usually, type IV skin burns rarely and always tans, type V skin always tans and is moderately pigmented (brown), and type VI skin always tans and is darkly pigmented (black). Fitzpatrick I and II skin types are commonly affected by NMSC and MM. The susceptibility to skin cancer, both NMSC and MM, is related to the melanin content of the skin and the skin s response to UV radiation. 

Ponnazhagan and Kwon (1992) reported a putative tissue-specific ds-element (TE-1) located at-236 bp of the mouse tyrosinase promoter. They partially purified a TE-1 binding protein (approximately 49 kDa in size), but tissue specificity remains to be confirmed by a more detailed analysis. For the human tyrosinase promoter, Shibata et al. (1992) identified a 200-bp pigment cell-specific enhancer, located between -2.0 and -1.8 kb. A minimum core sequence of 39 bp was shown to be sufficient to confer the specific activity, although other regions (not identified so far) within the 200-bp fragment are required for more efficient expression in melanoma cells (Shibata et al., 1992). 

In cultured melanoma cells, a carboxylic acid of latanoprost has been reported to increase melanogenesis [76], However, a carboxylic acid of tafluprost did not have the stimulatory effects on melanin content in cultured B16-F10 melanoma cells [72], It suggests the application of tafluprost may cause less pigmentation than do latanoprost. 

In beagle dogs, intravenously injected radium-226 was deposited in the melanin granules of pigmented cells and rodlike organelles of the tapetum in the eye (a structure that humans do not have). Retention in the eye varied inversely with dose. At doses from 0.062 to 1.1 pCi/kg (2.3 to 41 kBq/kg), loss of pigment at the higher doses and melanosis and intraocular melanoma formation at the lower doses were observed (Taylor et al. 1972). 

Most pulmonary tumor colonies in mice are in the pleura. Therefore, pigmented colonies (such as melanomas) can be counted without lung dissection. However, it may be more facile, especially when there are extensive pulmonary metastases, to dissect the lungs into the individual four or five lobes which are then enumerated individually using a dissecting microscope. 

Another obvious genetic aspect of toxicology has to do with the level in skin of melanin, a pigment that makes skin dark. Melanin levels vary widely with genotype. Melanin confers resistance to the effects of solar ultraviolet radiation, which is absorbed by DNA in skin cells, causing damage that in the worst-case results in deadly melanoma skin cancer. Skin melanin is a chromophore (a... 

Tatara, Y., Namba, T., Yamagata, Y., Yoshida, T., Uchida, T., and Ichishima, E. (2008). Acid activation of protyrosinase from Aspergillus oryzae homo-tetrameric protyrosinase is converted to active dimmers with an essential intersubunit disulfide bond at acidic pH. Pigment Cell Melanoma Res., 21, 89-96. 

Melanoma Cancer of the melanocytes or pigment cells of the skin tissue. 

Melnikova VO, Bar-Eli M. Bioimmunotherapy for melanoma using fully human antibodies targeting MCAM/MUC18 and IL-8. Pigmented Cell Res 2006 19 395 105. 

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