Transcriptional regulation of immunoglobulin expression in a chronic lymphocytic leukemia cell line.
A cell line derived from a B-type chronic lymphocytic leukemia, Corinna II, was found to down-regulate its steady-state level of IgM mRNA after treatment with phorbol 12-myristate 13-acetate while the proliferative capacity of the cell line was unaffected. No changes in the splicing pattern of the IgM transcript could be observed after treatment. The down-regulatory effect on IgM RNA expression was found to be inhibited by cycloheximide, suggesting that functional protein synthesis was needed for the effect. Transfection experiments showed that the down-regulatory effect of phorbol myristate acetate was exerted at the level of transcriptional initiation. The DNA element mediating the down-regulatory effect was found to be present within 140 bp 5' of the mRNA cap site in an immunoglobulin promoter.
Mårtensson
I L
IL
Department of Immunology, University of Uppsala Biomedical Center, Sweden.
Nilsson
K
K
Leanderson
T
T
D001402:B-Lymphocytes / Q000502:physiology*; D001483:Base Sequence; D002455:Cell Division / Q000187:drug effects; D004742:Enhancer Elements, Genetic; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D005803:Genes, Immunoglobulin; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000235:genetics; D007148:Immunoglobulin mu-Chains / Q000235:genetics; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000503:physiopathology*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects; D014407:Tumor Cells, Cultured
D007145:Immunoglobulin kappa-Chains; D007148:Immunoglobulin mu-Chains; D012333:RNA, Messenger; D013755:Tetradecanoylphorbol Acetate