Differential gene expression of the neural cell adhesion molecule (N-CAM) in a panel of multiple myeloma cell lines.
A striking feature of myeloma plasma cells concerns their expression of the neural cell adhesion molecule (N-CAM). The regulation of this particular expression is, however, not known. In this study, the N-CAM (CD56) gene regulation was examined in a panel of multiple myeloma (MM) cell lines. In this panel, both N-CAM-positive and -negative cells were analysed, reflecting the in vivo situation where a minority of MM patients have CD56-negative plasma cells at diagnosis or where in cases of extramedullary involvement CD56 expression decreases. At least two N-CAM mRNAs were found in the cell lines expressing the 140 kDa isoform. With one exception, no N-CAM transcripts could be detected in the N-CAM-negative cell lines. No structural differences could be found in the genomic organization of the N-CAM gene, or in the regulatory promoter region when CD56-positive and -negative cell lines were compared. In transfection studies, however, transcriptional activity of the N-CAM promoter was observed in N-CAM-negative cells, leading us to conclude that the up-regulation of N-CAM in MM cannot be explained by a simple transcriptional gene activation.
De Greef
C
C
Department of Haematology-Immunology, Free University of Brussels, Belgium.
Van Riet
I
I
Bakkus
M H
MH
Van Camp
B
B
D015703:Antigens, CD / Q000032:analysis / Q000096:biosynthesis; D019002:CD56 Antigen / Q000032:analysis / Q000096:biosynthesis*; D002460:Cell Line; D002872:Chromosome Deletion; D002880:Chromosomes, Human, Pair 11; D004171:Diploidy; D015972:Gene Expression Regulation, Neoplastic; D006238:Haploidy; D006801:Humans; D009101:Multiple Myeloma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D019006:Neural Cell Adhesion Molecules / Q000032:analysis / Q000096:biosynthesis*; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000096:biosynthesis; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D014407:Tumor Cells, Cultured
D015703:Antigens, CD; D019002:CD56 Antigen; D019006:Neural Cell Adhesion Molecules; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins