Linked Life Data

8789740

Source:http://linkedlifedata.com/resource/pubmed/id/8789740

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1996-10-23
pubmed:abstractText
Seventeen human melanoma cell (HMC) lines, both melanotic and amelanotic, were incubated in the continuous presence of a potent melanotropic peptide hormone analog, [Nle4,D-Phe7] alpha-MSH, for 72 hr with daily changes of medium. Only one cell line (HD, melanotic) consistently responded to the hormone analog by increased tyrosinase activity. Three (one melanotic, two amelanotic) of the HMC lines also failed to respond to the peptide by either increased or decreased enzyme activity when incubated continuously in the presence of the peptide for longer periods of time (6,15,27,43 days). The HD cell line, however, again responded with increasingly enhanced basal enzyme activity the longer the cells were incubated in the presence of the melanotropin. One amelanotic cell line (C8161) responded with enhanced enzyme activity when grown to confluency in the continuous presence of the peptide. Basal tyrosinase activity of the C8161 cell line may have increased as cell density in the flasks increased. These results suggest that under conditions of increased cell number, phenotypic expression of tyrosinase activity in so called "amelanotic" (tyrosinase-negative) cells is increased and can be enhanced further by stimulation with a melanotropic peptide. Under conditions of increased cell number, the presence of [Nle4,D-Phe7] alpha-MSH caused morphological differentiation (shape change); the cells became enlarged and very dendritic. The number of cells in monolayer (surface of the flask) and in the medium were drastically reduced in both melanotic and "amelanotic" cell lines incubated with [Nle4,D-Phe7] alpha-MSH. The data support other published reports that melanotropic peptides inhibit human melanoma cell growth (proliferation) in vitro, most likely through a cytostatic mechanism. [Nle4,D-Phe7] alpha-MSH also exhibited a prolonged (residual) inhibitory action on HD cell proliferation. In other words, inhibition of cell growth (proliferation) of the HMCs was evident even several days after removal of the melanotropic peptide from the incubation medium.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0893-5785
pubmed:author
pubmed:issnType
Print
pubmed:volume
8
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
314-23
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
The melanotropic peptide, [Nle4,D-Phe7] alpha-MSH, stimulates human melanoma tyrosinase activity and inhibits cell proliferation.
pubmed:affiliation
Department of Cell Biology, University of Arizona, Tucson 85724, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.