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EFFECT OF UVA IRRADIATION ON B16 MELANOMA CELLS IN MONOLAYER CULTURE
Author(s) -
Shono Shigeaki,
Terauchi Masami,
Toda Kiyoshi
Publication year - 1982
Publication title -
the journal of dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 65
eISSN - 1346-8138
pISSN - 0385-2407
DOI - 10.1111/j.1346-8138.1982.tb01080.x
Subject(s) - doubling time , tyrosinase , melanoma , irradiation , cell culture , melanin , cell growth , chemistry , microbiology and biotechnology , cell , andrology , biology , biochemistry , cancer research , enzyme , medicine , genetics , physics , nuclear physics
B16 murine melanoma cells in monolayer culture were exposed to a single dose of long wave ultraviolet light (UVA). The number of viable melanoma cells was decreased at 10 hrs post irradiation in parallel to the increase in UVA dose (10 4 ~10 7 ergs/cm 2 ). After ten hours, the cultured cells entered the logarithmic growth phase. The doubling time of the cells exposed to the low dose of UVA was similar to that of nonirradiated cells, but the exposure to higher doses of UVA (10 5 ~10 6 ergs/cm 2 ) elongated the doubling time of these cells. Still higher doses of UVA exposure (10 7 ergs/cm 2 ) caused no further elongation of doubling time. The tyrosinase activity of these melanoma cells was also measured using an oxygen electrode. The tyrosinase activity of each irradiated cell at ten hours was significantly increased, but no significant increase of tyrosinase activity per mg protein was observed, since protein content per cell increased at the same time. The increase in tyrosinase activity was still observed after ten hours in cells exposed to higher amounts of UVA. These results suggest that UVA repressed cell division and induced protein synthesis to prepare for melanogenesis.