Apoptosis is rapidly triggered by antisense depletion of MCL-1 in differentiating U937 cells
| Autor: | Da, Moulding, Rv, Giles, Dg, Spiller, White MR, Dm, Tidd, Steven Edwards |
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| Rok vydání: | 2000 |
| Předmět: |
Microscopy
Confocal Base Sequence Tumor Necrosis Factor-alpha Blotting Western Apoptosis Cell Differentiation U937 Cells DNA Antisense Neoplasm Proteins Gene Expression Regulation Neoplastic Organophosphorus Compounds Proto-Oncogene Proteins c-bcl-2 Humans Myeloid Cell Leukemia Sequence 1 Protein Tetradecanoylphorbol Acetate RNA Messenger |
| Zdroj: | Europe PubMed Central |
| ISSN: | 0006-4971 |
| Popis: | Mcl-1 is a member of the Bcl-2 protein family, which has been shown to delay apoptosis in transfection and/or overexpression experiments. As yet no gene knockout mice have been engineered, and so there is little evidence to show that loss of Mcl-1 expression is sufficient to trigger apoptosis. U937 cells constitutively express the antiapoptotic protein Bcl-2; but during differentiation, in response to the phorbol ester PMA (phorbol 12 beta-myristate 13 alpha-acetate), Mcl-1 is transiently induced. The purpose of this investigation was to determine the functional role played by Mcl-1 in this differentiation program. Mcl-1 expression was specifically disrupted by chimeric methylphosphonate/phosphodiester antisense oligodeoxynucleotides to just 5% of control levels. The depletion of Mcl-1 messenger RNA (mRNA) and protein was both rapid and specific, as indicated by the use of control oligodeoxynucleotides and analysis of the expression of other BCL2 family members and PMA-induced tumor necrosis factor-alpha (TNF-alpha). Specific depletion of Mcl-1 mRNA and protein, in the absence of changes in cellular levels of Bcl-2, results in a rapid entry into apoptosis. Levels of the proapoptotic protein Bax remained unchanged during differentiation, while Bak expression doubled within 24 hours. Apoptosis was detected within 4 hours of Mcl-1 antisense treatment by a variety of parameters including a novel live cell imaging technique allowing correlation of antisense treatment and apoptosis in individual cells. The induction of Mcl-1 is required to prevent apoptosis during differentiation of U937 cells, and the constitutive expression of Bcl-2 is unable to compensate for the loss of Mcl-1. (Blood. 2000;96:1756-1763) |
| Databáze: | OpenAIRE |
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