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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Animals, Apoptosis, Apoptosis Inducing Factor, Blotting, Western, Buthionine Sulfoximine, Cell Line, Tumor, Cercopithecus aethiops, Drug Synergism, Eugenol, Extracellular Signal-Regulated MAP Kinases, Glutathione, Hep G2 Cells, Humans, JNK Mitogen-Activated Protein Kinases, K562 Cells, Leukemia, Myelogenous, Chronic, BCR-ABL Positive, Mice, Microscopy, Confocal, NIH 3T3 Cells, Nitric Oxide, Nitric Oxide Synthase Type II, Reactive Oxygen Species, Signal Transduction, U937 Cells, Vero Cells.
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Does synergistic apoptosis of CML cells by buthionine sulfoximine and hydroxychavicol correlate with activation of AIF and GSH-ROS-JNK-ERK-iNOS pathway? Context: Hydroxychavicol (HCH), a constituent of Piper betle leaf has been reported to exert anti-leukemic activity through induction of reactive oxygen species (ROS). The aim of the study is to optimize the oxidative stress -induced chronic myeloid leukemic (CML) cell death by combining glutathione synthesis inhibitor, buthionine sulfoximine (BSO) with HCH and studying the underlying mechanism. Anti-proliferative activity of BSO and HCH alone or in combination against a number of leukemic (K562, KCL22, KU812, U937, Molt4), non-leukemic (A549, MIA-PaCa2, PC-3, HepG2) cancer cell lines and normal cell lines (NIH3T3, Vero) was measured by MTT assay. Apoptotic activity in CML cell line K562 was detected by flow cytometry (FCM) after staining with annexin V-FITC/propidium iodide (PI), detection of reduced mitochondrial membrane potential after staining with JC-1, cleavage of caspase- 3 and poly (ADP)-ribose polymerase proteins by western blot analysis and translocation of apoptosis inducing factor (AIF) by confocal microscopy. Intracellular reduced glutathione (GSH) was measured by colorimetric assay using GSH assay kit. 2',7'-dichlorodihydrofluorescein diacetate (DCF-DA) and 4-amino-5-methylamino-2',7'-difluorofluorescein (DAF-FM) were used as probes to measure intracellular increase in ROS and nitric oxide (NO) levels respectively. Multiple techniques like siRNA transfection and pharmacological inhibition were used to understand the mechanisms of action. Non-apoptotic concentrations of BSO significantly potentiated HCH-induced apoptosis in K562 cells. BSO potentiated apoptosis-inducing activity of HCH in CML cells by caspase-dependent as well as caspase-independent but apoptosis inducing factor (AIF)-dependent manner. Enhanced depletion of intracellular GSH induced by combined treatment correlated with induction of ROS. Activation of ROS- dependent JNK played a crucial role in ERK1/2 activation which subsequently induced the expression of inducible nitric oxide synthase (iNOS). iNOS- mediated production of NO was identified as an effector molecule causing apoptosis of CML cells.
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BSO synergizes with HCH in inducing apoptosis of CML cells through the GSH-ROS-JNK-ERK-iNOS pathway. Final Decision: yes