Degradation of alpha-melanocyte stimulating hormone (alpha-MSH) by CALLA/endopeptidase 24.11 expressed by human melanoma cells in culture.
Int J Cancer
; 46(6): 1124-30, 1990 Dec 15.
Article
em En
| MEDLINE
| ID: mdl-2174414
ABSTRACT
The common acute lymphoblastic leukemia antigen (CALLA) is identical to human endopeptidase 24.11 (E-24.11) and is expressed on certain human melanoma lines. This work was conducted in order to investigate whether alpha-melanocyte-stimulating hormone (alpha-MSH) could be a substrate for E-24.11, its degradation leading to the negative alpha-MSH radiobinding assay results observed with some CALLA-positive cell lines. We used 3 human melanoma cell lines (GLL-19, Mel Juso and G361) which lack receptors to alpha-MSH and express CALLA, and, as a control, one CALLA-negative melanoma cell line (HBL) with specific receptors for alpha-MSH. Radioimmunoassays give evidence that alpha-MSH was degraded in the presence of the 4 melanoma cell lines and that disappearance of the peptide was significantly reduced by phosphoramidon in 2 lines (GLL-19 and G361). Upon incubation of alpha-MSH with GLL-19 and G361 cell membranes, 3 degradation products were completely abolished in the presence of phosphoramidon. Amino acid content analysis of alpha-MSH fragments produced by purified E-24.11 permitted identification of 6 peptide bonds in the sequence of alpha-MSH susceptible to cleavage by the enzyme. It is concluded that alpha-MSH is a substrate in vitro for purified E-24.11 and for the enzyme present on the human melanoma cell lines GLL-19 and G361, expressing a high level of endopeptidase activity. However, hydrolysis of alpha-MSH by this enzyme does not seem to represent the main factor responsible for the apparent absence of receptors for the hormone on some cell lines.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Alfa-MSH
/
Neprilisina
/
Antígenos de Diferenciação
/
Melanoma
/
Antígenos de Neoplasias
/
Antígenos de Superfície
Tipo de estudo:
Clinical_trials
/
Health_economic_evaluation
/
Prognostic_studies
/
Risk_factors_studies
/
Screening_studies
Limite:
Humans
Idioma:
En
Revista:
Int J Cancer
Ano de publicação:
1990
Tipo de documento:
Article
País de afiliação:
Bélgica