Ecto-ATP diphosphohydrolase/CD39 is overexpressed in differentiated human melanomas.
Ecto-ATPase activities of melanocytes and human melanoma cell lines differing in the stage of progression were compared. A dramatic increase in ecto-ATPase activity above the level of normal melanocytes was demonstrated in the differentiated melanomas and was followed by a gradual decrease with tumor progression. The characteristics of this enzymatic activity were consistent with CD39/ecto-ATP diphosphohydrolase (ATPDase) which was found to be the major ecto-ATP-hydrolysing enzyme in melanomas. Indeed, the expression of CD39 and the level of CD39 mRNA followed a similar pattern. Since CD39 is known to regulate homotypic adhesion and, supposedly, affects the disaggregation step, we suggest that overexpression of CD39 may enable tumor cells to reduce contacts with T-lymphocytes and escape from immunological recognition.
Dzhandzhugazyan
K N
KN
Department of Tumor Cell Biology, Institute of Cancer Biology, Danish Cancer Society, Copenhagen, Denmark.
Kirkin
A F
AF
thor Straten
P
P
Zeuthen
J
J
D000251:Adenosine Triphosphatases; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism*; D001081:Apyrase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D002460:Cell Line; D018450:Disease Progression; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008544:Melanocytes; D008545:Melanoma / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D012333:RNA, Messenger / Q000032:analysis; D012334:RNA, Neoplasm / Q000032:analysis; D014407:Tumor Cells, Cultured
D015703:Antigens, CD; D014408:Biomarkers, Tumor; D004791:Enzyme Inhibitors; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D000251:Adenosine Triphosphatases; D001081:Apyrase; C067869:CD39 antigen