Molecular mechanism of tyrosinase regulation by L-dopa in hamster melanoma cells.
Exposure of hamster amelanotic melanoma cells to L-dihydroxyphenylalanine (L-DOPA) resulted in a time dependent increase of cell pigmentation, tyrosinase concentration and activity with peak after 24 hours. Northern blot analysis showed a small but reproducible increase of tyrosinase mRNA after 3 hours and a decrease below the control level after 9 hours. After 24 and 48 hours tyrosinase mRNA was undetectable. It is suggested that L-DOPA or its oxidation products can stimulate intracellular tyrosinase concentration and regulate tyrosinase mRNA level both in positive and negative fashion.
Slominski
A
A
Department of Microbiology and Immunology, Albany Medical College, NY 12208.
Costantino
R
R
D000818:Animals; D003001:Cloning, Molecular; D006224:Cricetinae; D004334:Drug Administration Schedule; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D007424:Intracellular Fluid / Q000378:metabolism; D007980:Levodopa / Q000494:pharmacology*; D008543:Melanins / Q000096:biosynthesis; D008545:Melanoma / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D014442:Monophenol Monooxygenase / Q000235:genetics / Q000378:metabolism*; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured
D008543:Melanins; D012333:RNA, Messenger; D007980:Levodopa; D014442:Monophenol Monooxygenase