HRF20/CD59 complement regulatory protein expression is phenotype-dependent and inducible by the hypomethylating agent 5-azacytidine on Burkitt's lymphoma cell lines.
We studied the expression of the 20-kDa homologous restriction factor (CD59/HRF20), a complement regulatory protein, on two subsets of blood derived B cells and on Burkitt's lymphoma lines. Both low-density (activated) and high-density (resting) B cell populations expressed high levels of CD59. CD59 was detectable, however, only on a minority of cells or not at all on three Epstein-Barr virus (EBV)-negative BL lines (BL41, BL28 and DG75) and on clones of an EBV-positive BL line (Mutu) that phenotypically resembled resting B lymphocytes. On the other hand, CD59 was detected at high or medium levels on Mutu cells which had a lymphoblastoid cell-like phenotype. Expression of CD59 was upregulated by 5-azacytidine, a drug inhibiting cytosine methylation, on CD59-negative cell lines. Induction was accompanied by a partial hypomethylation in the 5' region of CD59 coding sequences.
Kuraya
M
M
Department of Tumor Biology, Karolinska Institute, Stockholm, Sweden.
Minarovits
J
J
Okada
H
H
Klein
E
E
D015703:Antigens, CD / Q000096:biosynthesis* / Q000235:genetics; D001374:Azacitidine / Q000494:pharmacology*; D001402:B-Lymphocytes / Q000187:drug effects; D002051:Burkitt Lymphoma / Q000276:immunology* / Q000473:pathology; D018957:CD59 Antigens; D002461:Cell Line, Transformed; D004273:DNA, Neoplasm / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects; D004854:Herpesvirus 4, Human; D006801:Humans; D016130:Immunophenotyping; D008213:Lymphocyte Activation / Q000187:drug effects; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D008745:Methylation; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
D015703:Antigens, CD; D018957:CD59 Antigens; D004273:DNA, Neoplasm; D008562:Membrane Glycoproteins; D001374:Azacitidine