Camptothecin and khat (Catha edulis Forsk.) induced distinct cell death phenotypes involving modulation of c-FLIPL, Mcl-1, procaspase-8 and mitochondrial function in acute myeloid leukemia cell lines
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Date
2009-11-13Author
Bredholt T
Dimba, Elizabeth A.
Hagland Hanne R.
Wergeland Line.
Skavland Jørn
Fossan Kjell O.
Tronstad, Karl J
Johannessen, Anne C.
Vintermyr, Olav K
Gjertsen, Bjørn T
Type
Journal ArticleMetadata
Show full item recordAbstract
Abstract
Background
An organic extract of the recreational herb khat (Catha edulis Forsk.) triggers cell death in various leukemia cell lines in vitro. The chemotherapeutics camptothecin, a plant alkaloid topoisomerase I inhibitor, was tested side-by-side with khat in a panel of acute myeloid leukemia cell lines to elucidate mechanisms of toxicity.
Results
Khat had a profound effect on MOLM-13 cells inducing mitochondrial damage, chromatin margination and morphological features of autophagy. The effects of khat on mitochondrial ultrastructure in MOLM-13 correlated with strongly impaired routine respiration, an effect neither found in the khat-resistant MV-4-11 cells nor in camptothecin treated cells. Enforced expression of anti-apoptotic Bcl-2 protein provided protection against camptothecin-induced cell death and partly against khat toxicity. Khat-induced cell death in MOLM-13 cells included reduced levels of anti-apoptotic Mcl-1 protein, while both khat and camptothecin induced c-FLIPL cleavage and procaspase-8 activation.
Conclusion
Khat activated a distinct cell death pathway in sensitive leukemic cells as compared to camptothecin, involving mitochondrial damage and morphological features of autophagy. This suggests that khat should be further explored in the search for novel experimental therapeutics.
URI
http://www.ncbi.nlm.nih.gov/pubmed/19912650http://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/14736