Expression of the c-myc protein is down-regulated at the terminal stages during in vitro differentiation of B-type chronic lymphocytic leukemia cells
| Autor: | Kenneth Nilsson, Marina Schena, J. Sällström, Lars-Gunnar Larsson, Mats Carlsson |
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| Rok vydání: | 1991 |
| Předmět: |
Cellular differentiation
Chronic lymphocytic leukemia Immunology Biology Lymphocyte Activation Biochemistry Proto-Oncogene Proteins c-myc Immunoglobulin lambda-Chains Antigen Gene expression medicine Humans RNA Messenger RNA Neoplasm Regulation of gene expression Oncogene Cell Cycle Cell Differentiation DNA Neoplasm Cell Biology Hematology Cell cycle Blotting Northern medicine.disease Leukemia Lymphocytic Chronic B-Cell Molecular biology Gene Expression Regulation Neoplastic Ki-67 Antigen Antigens Surface CD5 Cell Division |
| Zdroj: | Blood. 77:1025-1032 |
| ISSN: | 1528-0020 0006-4971 |
| DOI: | 10.1182/blood.v77.5.1025.1025 |
| Popis: | The translocated c-myc oncogene in Burkitt's lymphoma (BL) and murine plasmacytoma (MPC) has been proposed to be expressed at a stage of differentiation at which the gene is normally silent, resulting in a continuous proliferation and an inhibited terminal differentiation. To determine whether c-myc is differently expressed at the various stages of the differentiation pathway, we used B-type chronic lymphocytic leukemia (B-CLL) cells, representing resting B lymphocytes, inducible to proliferation and/or differentiation in vitro. The c-myc protein, and Ig lambda-light chain and PCA-1 antigen as markers of B-cell maturation, were analyzed in single, morphologically defined cells by immunocytochemical double-staining. The proliferation of individual cells was determined by 3H-thymidine incorporation and by analysis of Ki-67 antigen expression. The results show that the level of c-myc expression correlates to the stage of differentiation and to the proliferative activity. Uninduced resting cells did not express c-myc. The c-myc protein was observed in the highest amount at the proliferative B-lymphoblast stage of maturation and was reduced in plasmablasts and undetectable in plasma cells. The results suggest that maturation of B cells into nonproliferative, terminally differentiated plasma cells is associated with a downregulated c-myc expression and thus support the view that the deregulated c-myc gene in BL and MPC is expressed at an inappropriate stage of maturation and thereby inhibits terminal differentiation. |
| Databáze: | OpenAIRE |
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