title: Sanguinarine-dependent induction of apoptosis in primary effusion lymphoma cells.
abstract: Primary effusion lymphoma (PEL) is an incurable, aggressive B-cell malignancy that develops rapid resistance to conventional chemotherapy. In efforts to identify novel approaches to block proliferation of PEL cells, we found that sanguinarine, a natural compound isolated from the root plant Sanguinaria canadendid, inhibits cell proliferation and induces apoptosis in a dose-dependent manner in several PEL cell lines. Our data show that sanguinarine treatment of PEL cells results in up-regulation of death receptor 5 (DR5) expression via generation of reactive oxygen species (ROS) and causes activation of caspase-8 and truncation of Bid (tBid). Subsequently, tBid translocates to the mitochondria causing conformational changes in Bax, leading to loss of mitochondrial membrane potential and release of cytochrome c to the cytosol. Sanguinarine-induced release of cytochrome c results in activation of caspase-9 and caspase-3 and poly(ADP-ribose) polymerase (PARP) cleavage, leading to induction of caspase-dependent apoptosis. In addition, we show that pretreatment of PEL cells with carbobenzoxy-Val-Ala-Asp-fluoromethylketone, a universal inhibitor of caspases, abrogates caspase and PARP activation and prevents cell death induced by sanguinarine. Moreover, treatment of PEL cells with sanguinarine down-regulates expression of inhibitor of apoptosis proteins (IAP). Finally, N-acetylcysteine, an inhibitor of ROS, inhibits sanguinarine-induced generation of ROS, up-regulation of DR5, Bax conformational changes, activation of caspase-3, and down-regulation of IAPs. Taken together, our findings suggest that sanguinarine is a potent inducer of apoptosis of PEL cells via up-regulation of DR5 and raise the possibility that this agent may be of value in the development of novel therapeutic approaches for the treatment of PEL.
authors: Human Cancer Genomic Research, King Fahad National Center for Children's Cancer and Research, Biological and Medical Research, Riyadh 11211, Saudi Arabia.
authors: Azhar R
authors: AR
authors: Hussain
authors: Naif A
authors: NA
authors: Al-Jomah
authors: Abdul K
authors: AK
authors: Siraj
authors: Pulicat
authors: P
authors: Manogaran
authors: Khalid
authors: K
authors: Al-Hussein
authors: Jehad
authors: J
authors: Abubaker
authors: Leonidas C
authors: LC
authors: Platanias
authors: Khawla S
authors: KS
authors: Al-Kuraya
authors: Shahab
authors: S
authors: Uddin
mesh_terms: D000470:Alkaloids / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D051023:BH3 Interacting Domain Death Agonist Protein / Q000378:metabolism; D053119:Benzophenanthridines / Q000494:pharmacology*; D020169:Caspases / Q000378:metabolism; D048708:Cell Growth Processes / Q000187:drug effects; D045744:Cell Line, Tumor; D024161:Collagen Type XI / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D005122:Exudates and Transudates / Q000166:cytology; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D007546:Isoquinolines / Q000494:pharmacology*; D016393:Lymphoma, B-Cell / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D008968:Molecular Conformation; D017382:Reactive Oxygen Species / Q000378:metabolism; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000096:biosynthesis / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D000470:Alkaloids; C494826:BAX protein, human; D051023:BH3 Interacting Domain Death Agonist Protein; C494814:BID protein, human; D053119:Benzophenanthridines; C499319:COL11A2 protein, human; D024161:Collagen Type XI; D007527:Isoenzymes; D007546:Isoquinolines; D017382:Reactive Oxygen Species; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D051028:bcl-2-Associated X Protein; D045304:Cytochromes c; C005705:sanguinarine; D020169:Caspases