Melanotropic activity of gamma MSH peptides in melanoma cells.
We studied the pigmentary activity of the peptides gamma 1, gamma 2 and gamma 3 melanocyte stimulating hormone (MSH), which differ in the structure of their C-termini, using hamster and mouse melanoma cell lines responsive to beta-MSH by increasing tyrosinase activity. Gamma 1-MSH alone or in combination with beta-MSH had no effect on either cell line. Gamma 2-MSH alone was biologically inactive but potentiated beta-MSH stimulation of tyrosinase activity. Gamma 3-MSH at high concentration (10 microM) induced tyrosinase activity and dendrite formation in the hamster melanoma line. When added together with beta-MSH, gamma 3-MSH partially inhibited the tyrosinase activity response to beta-MSH. Thus, gamma-MSH peptides have low intrinsic melanotropic activity in mammalian melanoma cells; the specific pigmentary responses appear to be affected by the structure of the C-terminal portion.
Slominski
A
A
Department of Microbiology, Immunology & Molecular Genetics, Albany Medical College, NY 12208.
Costantino
R
R
Wortsman
J
J
Paus
R
R
Ling
N
N
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D006224:Cricetinae; D066298:In Vitro Techniques; D009074:Melanocyte-Stimulating Hormones / Q000494:pharmacology*; D008545:Melanoma / Q000503:physiopathology*; D051379:Mice; D008969:Molecular Sequence Data; D014442:Monophenol Monooxygenase / Q000378:metabolism; D010641:Phenotype; D010858:Pigmentation / Q000187:drug effects; D014407:Tumor Cells, Cultured
D009074:Melanocyte-Stimulating Hormones; D014442:Monophenol Monooxygenase