Expression of the galactose binding protein Mac-2 by human melanoma cell-lines.
The Mac-2 protein is a lectin specific for galactose-containing glycoconjugates. Present in some normal cells, it was also associated with the metastatic potential of some carcinoma cells. We studied Mac-2 expression in three human melanoma cell lines and in five variants and clones from one of them. By using the M3/38 rat monoclonal antibody, Mac-2 was demonstrated on cell surface by flow cytometry as well as in the cytoplasm and in the nucleus by confocal microscopy. The expression of Mac-2 was not correlated with that of terminal unsialylated Gal beta 1-3 GalNac structures on metastatic melanoma cell lines. However, the presence of extracellular Mac-2 containing vesicles was observed in cell lines with metastatic potency. Western blot analysis of cell lysates, in reducing or non-reducing conditions, revealed two bands of 34-36 and 93-98 kDa apparent M(r), also found in HL60 and P388.D1 cell lines used as positive controls.
Laboratoire d'Immunologie INSERM 080, Hopital E. Herriot, Lyon, France.
A
A
Mey
O
O
Berthier-Vergnes
P A
PA
Apoil
J F
JF
Doré
J P
JP
Revillard
D000943:Antigens, Differentiation / Q000032:analysis*; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins / Q000032:analysis*; D037502:Galectin 3; D006801:Humans; D008545:Melanoma / Q000737:chemistry*; D008970:Molecular Weight; D009004:Monosaccharide Transport Proteins; D033902:Periplasmic Binding Proteins; D014407:Tumor Cells, Cultured
D000943:Antigens, Differentiation; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; D037502:Galectin 3; D009004:Monosaccharide Transport Proteins; D033902:Periplasmic Binding Proteins; C023550:galactose-binding protein