title: Induction of apoptosis in human Hep3B hepatoma cells by norcantharidin through a p53 independent pathway via TRAIL/DR5 signal transduction.
abstract: OBJECTIVE
  To investigate the inhibitory activities of norcantharidin (NCTD), a demethylated analogue of cantharidin, on Hep3B cells (a human hepatoma cell line) with deficiency of p53.
  
  
  METHODS
  The survival rate of the Hep3B cells after treating with NCTD was measured by MTT assay. Cell cycle of treated cells was analyzed by flow cytometry, and DNA fragmentation was observed by electrophoresis. The influence of inhibitors for various caspases and anti-death receptors antibodies on the NCTD-induced apoptosis in the cells was determined.
  
  
  RESULTS
  NCTD treatment resulted in growth inhibition of Hep3B cells in a dose- and time-dependent manner. Cell cycle analysis of the cells after treatment with NCTD for 48 h shows that NCTD induced G(2)M phase arrest occurs at low concentration ([Symbol: see text] 25 μmol/L) but G(0)G(1) phase arrest at high concentration (50 μmol/L). The addition of both caspase-3 and caspase-10 inhibitors completely inhibited DNA fragmentation. Addition of anti-TRAIL/DR5 antibody significantly inhibited DNA fragmentation.
  
  
  CONCLUSIONS
  NCTD may inhibit the proliferation of Hep3B cells by arresting cell cycle at G(2)M or G(0)G(1) phase, and induce cells apoptosis via TRAIL/DR5 signal transduction through activation of caspase-3 and caspase-10 by a p53-independent pathway.
authors.affiliation: Department of Neurology, Show Chwan Memorial Hospital, Changhua, Taiwan, China.
authors.forename: Chung-Hsin
authors.initials: CH
authors.lastname: Yeh
authors.forename: Yu-Yen
authors.initials: YY
authors.lastname: Yang
authors.forename: Ya-Fang
authors.initials: YF
authors.lastname: Huang
authors.forename: Kuan-Chih
authors.initials: KC
authors.lastname: Chow
authors.forename: Ming-Feng
authors.initials: MF
authors.lastname: Chen
mesh_terms: D000912:Antibodies, Neoplasm / Q000494:pharmacology; D057134:Antibodies, Neutralizing / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology*; D006528:Carcinoma, Hepatocellular / Q000201:enzymology / Q000473:pathology*; D053455:Caspase 10 / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D061945:Caspase Inhibitors / Q000494:pharmacology; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D053938:DNA Fragmentation / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000201:enzymology / Q000473:pathology*; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D000912:Antibodies, Neoplasm; D057134:Antibodies, Neutralizing; D019086:Bridged Bicyclo Compounds, Heterocyclic; D061945:Caspase Inhibitors; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D053221:TNF-Related Apoptosis-Inducing Ligand; D016159:Tumor Suppressor Protein p53; C069741:norcantharidin; D053455:Caspase 10; D053148:Caspase 3