title: A3 adenosine receptor-mediated p53-dependent apoptosis in Lu-65 human lung cancer cells.
abstract: OBJECTIVE
  A(3) adenosine receptor mediates apoptosis in cancer cells via diverse signaling pathways. The present study examined A(3) adenosine receptor-mediated apoptosis in Lu-65 cells, a human giant cell lung carcinoma cell line.
  
  
  METHODS
  MTT assay, TUNEL staining, real-time RT-PCR, Western blotting, and assay of caspase-3, -8, and -9 activities were carried out in Lu-65 cells, and A(3) adenosine receptor or p53 was knocked-down by transfecting each siRNA into cells.
  
  
  RESULTS
  Extracellular adenosine induces Lu-65 cell apoptosis in a concentration (0.01-10 mM)-dependent manner, and the effect was inhibited by the A(3) adenosine receptor inhibitor MRS1191 or by knocking-down A(3) adenosine receptor or p53. Like adenosine, the A(3) adenosine receptor agonist 2-Cl-IB-MECA also induced Lu-65 cell apoptosis. Adenosine upregulated expression of p53 and Noxa mRNAs and activated caspase-3 and -9, but not caspase-8. Those adenosine effects were still inhibited by knocking-down A(3) adenosine receptor or p53.
  
  
  CONCLUSIONS
  The results of the present study show that adenosine upregulates p53 expression via A(3) adenosine receptor, to promote p53-dependent Noxa gene transcription, causing activation of caspase-9 and the effector caspase-3 to induce Lu-65 cell apoptosis.
authors: Division of Bioinformation, Department of Physiology, Hyogo College of Medicine, Nishinomiya, Japan.
authors: Tai-ichiro
authors: T
authors: Otsuki
authors: Takeshi
authors: T
authors: Kanno
authors: Yumiko
authors: Y
authors: Fujita
authors: Chiharu
authors: C
authors: Tabata
authors: Kazuya
authors: K
authors: Fukuoka
authors: Takashi
authors: T
authors: Nakano
authors: Akinobu
authors: A
authors: Gotoh
authors: Tomoyuki
authors: T
authors: Nishizaki
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology; D058909:Adenosine A3 Receptor Agonists / Q000494:pharmacology; D058918:Adenosine A3 Receptor Antagonists / Q000494:pharmacology; D017209:Apoptosis; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival; D004095:Dihydropyridines / Q000494:pharmacology; D004789:Enzyme Activation; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D006801:Humans; D008175:Lung Neoplasms; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D043684:Receptor, Adenosine A3 / Q000235:genetics / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
chemical_list: D058909:Adenosine A3 Receptor Agonists; D058918:Adenosine A3 Receptor Antagonists; D004095:Dihydropyridines; C107728:MRS 1191; C498702:PMAIP1 protein, human; D019253:Proto-Oncogene Proteins c-bcl-2; D043684:Receptor, Adenosine A3; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D020169:Caspases; D000241:Adenosine; C090034:2-chloro-N(6)-(3-iodobenzyl)adenosine-5'-N-methyluronamide