title: The activation of p38 and JNK by ROS, contribute to OLO-2-mediated intrinsic apoptosis in human hepatocellular carcinoma cells.
abstract: In this study, we describe that a novel synthesized compound, olean-28,13β-olide 2 (OLO-2), exhibits selective cytotoxic activity via inducing apoptosis in human hepatocellular carcinoma (HCC) cell lines but not normal human hepatic cells in vitro. Exposure of human HCC HepG2 cells to OLO-2 results in significant loss of mitochondrial transmembrane potential (ΔΨm), the release of cytochrome c, the recruitment of B-cell lymphoma 2 (Bcl-2) assaciated X protein (Bax) and the downregulation of Bcl-2. The apoptosis induced by OLO-2 is associated with the activation of caspase-3/9 and the nuclear translocation of apoptosis inducing factor (AIF). Moreover, the increase of phosphorylated p38 and c-Jun N-terminal kinase (JNK) is observed. OLO-2-induced the externalization of phosphatidyl-serine (PS) and the loss of ΔΨm are blocked by p38 inhibitor SB203580 or JNK inhibitor SP600125. In addition, OLO-2 provokes the generation of reactive oxygen species (ROS) in HepG2 cells, while the antioxidant N-acetyl cysteine (NAC) almost completely blocks OLO-2-induced apoptosis and the activation of p38 and JNK. Taken together, the present study demonstrates that OLO-2 exhibits its cytotoxic activity through intrinsic apoptosis via ROS generation and the activation of p38 and JNK. Its potential to be a candidate of anti-cancer agent is worth being further investigated.
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China; School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, PR China.
authors.forename: Zhenzhen
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China; Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing 210009, PR China.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Center of Drug Discovery, China Pharmaceutical University, Nanjing 210009, PR China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China.
authors.forename: Lifang
authors.initials: L
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Ling
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China.
authors.forename: Ling
authors.initials: L
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China. Electronic address: huijicpu@163.com.
authors.forename: Hui
authors.initials: H
authors.lastname: Ji
authors.affiliation: Center of Drug Discovery, China Pharmaceutical University, Nanjing 210009, PR China. Electronic address: zyhtgd@sohu.com.
authors.forename: Yihua
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000201:enzymology / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D004789:Enzyme Activation; D020536:Enzyme Activators / Q000494:pharmacology*; D006801:Humans; D008113:Liver Neoplasms / Q000201:enzymology / Q000378:metabolism / Q000473:pathology*; D048670:MAP Kinase Kinase 4 / Q000378:metabolism*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology*; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
chemical_list: D020536:Enzyme Activators; D047428:Protein Kinase Inhibitors; D017382:Reactive Oxygen Species; C000591673:olean-28-13beta-olide-2; D009828:Oleanolic Acid; D048051:p38 Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4
keywords: Apoptosis; Cytotoxic; Human HCC cells; Mitochondria; OLO-2