Enhanced expression of HLA-DR antigens by the human melanoma cell line CaCL 73-36 upon induction of a less differentiated phenotype with bromodeoxyuridine.
The effects of bromodeoxyuridine (BUdr) on the in vitro growth, morphology and expression of HLA-DR antigens in the human melanoma line CaCL 73-36 were studied. Treatment of melanoma cells with BUdr resulted in an inhibition of growth with 30-35% reduction in saturation density at 2 micrograms/ml and 50-54% reduction at 4 micrograms/ml. BUdr-treated melanoma cells showed marked morphological changes including more flattened and epithelial cell shapes. These changes are consistent to a less differentiated phenotype. Quantitative absorption analysis using an anti HLA-DR monoclonal antibody revealed that the expression of surface HLA-DR antigens was enhanced by up to 2.5-fold in a BUdr dose-dependent manner. This enhancement could be related to an increased synthesis of HLA-DR antigens rather than a decrease shedding of these antigens. Further studies are needed to fully elucidate the biological significance and mechanism of action of BUdr in causing such altered HLA-DR expression.
D001973:Bromodeoxyuridine / Q000494:pharmacology*; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D006681:HLA-D Antigens / Q000096:biosynthesis*; D006684:HLA-DR Antigens / Q000096:biosynthesis*; D006801:Humans; D008545:Melanoma / Q000276:immunology*; D010641:Phenotype; D013936:Thymidine / Q000378:metabolism
D006681:HLA-D Antigens; D006684:HLA-DR Antigens; D001973:Bromodeoxyuridine; D013936:Thymidine