Proliferation, melanocyte

Hirobe, T. (1992). Control of melanocyte proliferation and differentiation in the mouse epidermis. Pigment Cell Res. 5 1-11. 

Several other activities are reported for Astragalus spp. the cycloartane saponins from A. sieversienus show an hypocholesterolemic action [219], while astramembrannin I, 87, and astrasieversianin I, 92 produce antileukocytopenic and anti-stress effects in mice [319]. Aqueous extract of A. membranaceus root causes significant stimulation of melanocyte proliferation using the sulphorhodamine B (SRB) test. This result supports the use of these extracts in traditional treatments of vitiligo [191]. 

The data on a causal relationship between cumulative W R exposure and malignant melanoma is not conclusive, but there is strong evidence that intermittent intense sunlight exposure, particularly severe sunburn in childhood, is a major risk factor for development of malignant melanoma (284-286). There is scientific evidence that UVB can induce melanocyte proliferation in both exposed and covered areas of the body (287), which explains why malignant melanoma sometimes occurs in unexposed parts of the body. 

Several proteins that affect intracellular calcium metabolism including annexin VI, cap-g, annexin V, calmodulin, calretinin, and S-100 protein can be seen in melanocytic proliferations. Only two of those have definite diagnostic importance and are discussed further here. 

Katoulis AC, Kanelleas A, Zambacos G, Panayiotides I, Stavrianeas NG. Development of two primary malignant melanomas after treatment with adalimumab a case report and review of the possible link between biological therapy with TNF-alpha antagonists and melanocytic proliferation. Dermatology 2010 221(1) 9-12. 

Melanocyte stimulants are of interest as potential treatments for the depigmentary skin disorder vitiligo. Black pepper water extract and piperine promote melanocyte proliferation in vitro. Black pepper extract was found to possess growth-stimulatory activity in cultured melanocytes [81]. Its aqueous extract at 0.1 mg/mL was observed to cause nearly 300 % stimulation of the growth of a cultured mouse melanocyte line, in 8 days hence, it is inferred that piperine is a potential repigmenting agent for the treatment of vitiligo. 

Koul IB, Kapil A (1993) Evaluation of the liver protective potential of piperine, an active principle of black and long peppers. Planta Med 59 413 17 81. Lin Z, Hoult JR, Bennett DC, Raman A (1999) Stimulation of mouse melanocyte proliferation by Piper nigrum fruit extract and its main alkaloid - piperine. Planta Med 65 600-603... 

III. ROLE OF THE DOMINANT SPOTTING LOCUS AND THE STEEL LOCUS IN THE MIGRATION AND PROLIFERATION OF MELANOCYTES... 

Spanakis, E., Lamina, P, and Bennett, D. C. (1992). Effects of the developmental colour mutations silver and recessive spotting on proliferation of diploid and immortal mouse melanocytes in culture. Development 114 675-680. 

Rudolph, P., Lappe, T., Schubert, C., Schubert, C., Schmidt, D., Parwaresch, R. M., and Christophers, E. 1995. Diagnostic assessment of two novel proliferation-specific antigens in benign and malignant melanocytic lesions. Am. J. Pathol. 747 1615-1625. 

A great number of tissue-specific promoters has been isolated and characterized, and some of these have been used in experimental cancer gene therapy (see Table 1). Obviously, tissue-specific promoters are also active in the normal tissue from which the tumor originated. Unless the loss of these normal cells is acceptable (as in the case of melanocytes), additional specificity mechanisms need to be considered to make the resulting vector useful for a systemic delivery. This can be achieved, for example, by introducing an additional level of specificity, such as a specificity for proliferating cells or a selectivity for other conditions that are characteristic of tumor cells (see later). 

The accelerated shedding of corneocytes disrupts the protective barrier function of the epidermis. From there, a cascade of secondary events stimulates growth in the basal layer of the epidermis and accelerates the conversion of keratinocytes into corneocytes" to restore optimum barrier function as soon as possible. Stimulation of the mother cells by the keratinocytes of the basal layer can unfortunately go hand in hand with reactional and inflammatory melanocyte stimulation, the cause of potential pigmentary changes. The stimulation of keratinocyte growth is also accompanied by positive stimulation of fibroblast proliferation and synthesis of proteins in the dermis (collagen, elastin and glycosaminoglycans)."... 

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