1. The anticancer drug mithramycin A sensitises tumour cells to apoptosis induced by tumour necrosis factor (TNF).
- Author
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Duverger, V, Murphy, A-M, Sheehan, D, England, K, Cotter, TG, Hayes, I, and Murphy, FJ
- Subjects
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TUMOR necrosis factors , *GENE expression , *APOPTOSIS , *CYTOKINES , *NF-kappa B , *CANCER cells - Abstract
In this report we show that mithramycin considerably increases the direct cytotoxic effect of tumour necrosis factor (TNF) on tumour cells in vitro. Sensitisation to TNF-induced apoptosis was prevented by the broad caspase inhibitor zVAD-fmk, whereas overexpression of Bcl-2 had no effect. Mithramycin also potentiated cell death induced by Fas agonistic antibodies. In contrast, mithramycin reduced the percentage of cells undergoing apoptosis due to factor withdrawal. TNF-induced activation of NF-kappaB (NF-kB)-dependent gene expression was not modulated by mithramycin treatment. Concomitantly with the increased sensitivity, the protein level of the short-spliced cFLIP variant was downregulated. These results indicate that mithramycin enhances TNF-induced cell death in an NF-kB-independent manner, and suggest that the Fas-associated death domain protein plays a crucial role in the TNF-sensitising effect of mithramycin. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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