Alpha-melanocyte-stimulating hormone immunoreactivity in human melanoma metastases extracts.
Seven human melanoma metastases were extracted in order to check the possible presence of any alpha-melanocyte stimulating hormone (MSH) immunoreactivity. The aim of that study was to provide some explanation for, mainly, two observations that we have already made and reported: 1) increased plasma alpha-MSH levels in melanoma of tumour-bearing patients as compared with tumour-free patients; 2) the presence of specific alpha-MSH receptors on human melanoma cells in culture. We could measure large amounts of immunoreactive alpha-MSH in all tumours ranging from 0.31 to 4.27 pmoles per g of wet tissue. Further identification of the extracted material by high-performance liquid chromatography revealed compounds of higher molecular weight and more hydrophobic than synthetic alpha-MSH. In addition, purified extracts could also displace 125I-labelled alpha-MSH from its cellular binding sites in an alpha-MSH specific radio-receptor binding assay. Our findings would suggest a possible presence of some hormone precursor(s) inside the melanoma tumours.
Ghanem
G
G
LOCE, J. Bordet Institute, Université Libre de Bruxelles, Belgium.
Verstegen
J
J
Libert
A
A
Arnould
R
R
Lejeune
F
F
D000368:Aged; D000369:Aged, 80 and over; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000276:immunology* / Q000473:pathology; D011863:Radioimmunoassay; D011869:Radioligand Assay / Q000379:methods; D011979:Receptors, Pituitary Hormone / Q000276:immunology / Q000378:metabolism; D014020:Tissue Extracts / Q000276:immunology* / Q000378:metabolism; D000521:alpha-MSH / Q000276:immunology* / Q000302:isolation & purification / Q000378:metabolism
D011979:Receptors, Pituitary Hormone; D014020:Tissue Extracts; D000521:alpha-MSH; C029446:MSH receptor