title: Two novel aspirin analogues show selective cytotoxicity in primary chronic lymphocytic leukaemia cells that is associated with dual inhibition of Rel A and COX-2.
abstract: OBJECTIVE
  Non-steroidal anti-inflammatory drugs have been shown to induce apoptosis in primary B-cell chronic lymphocytic leukaemia (CLL) cells, but the molecular mechanisms that underpin this observation have not been fully elucidated. Here, we have analysed the effect two novel aspirin analogues, 2-hydroxy benzoate zinc (2HBZ) and 4-hydroxy benzoate zinc (4HBZ), on primary CLL samples.
  
  
  METHODS
  Cytotoxic effects of 2HBZ and 4HBZ were analysed in primary CLL cells derived from 52 patients, and normal B- and T-lymphocytes. Mechanisms of action of these agents were also elucidated.
  
  
  RESULTS
  Both analogues induced apoptosis in a dose-dependent and time-dependent manner. Apoptosis was associated with activation of caspase-3 that could be partially abrogated by the caspase-9 inhibitor (Z-LEHD.fmk). Importantly, both agents demonstrated preferential cytotoxicity in CLL cells when compared to normal B- and T-lymphocytes. In terms of their molecular mechanisms of action, 4HBZ and 2HBZ inhibited COX-2 transcription and protein expression and this was associated with upstream inhibition of transcription factor Rel A. Co-culture of CLL cells with CD40 ligand-expressing mouse fibroblasts significantly increased COX-2 expression and inhibited spontaneous apoptosis. Importantly, the most potent analogue, 4HBZ, overcame pro-survival effects of the co-culture system and significantly repressed COX-2. Finally, elevated COX-2 expression was associated with poor prognostic subsets and increased sensitivity to 4HBZ.
  
  
  CONCLUSIONS
  Our results demonstrate therapeutic potential of 4HBZ and are consistent with a mechanism involving suppression of Rel A nuclear translocation and inhibition of COX-2 transcription.
authors.affiliation: Department of Haematology, School of Medicine, Cardiff University, Heath Park, UK. peppercj@cf.ac.uk
authors.forename: C
authors.initials: C
authors.lastname: Pepper
authors.forename: J G
authors.initials: JG
authors.lastname: Mahdi
authors.forename: A G S
authors.initials: AG
authors.lastname: Buggins
authors.forename: S
authors.initials: S
authors.lastname: Hewamana
authors.forename: E
authors.initials: E
authors.lastname: Walsby
authors.forename: E
authors.initials: E
authors.lastname: Mahdi
authors.forename: A
authors.initials: A
authors.lastname: Al-Haza'a
authors.forename: A J
authors.initials: AJ
authors.lastname: Mahdi
authors.forename: T T
authors.initials: TT
authors.lastname: Lin
authors.forename: L
authors.initials: L
authors.lastname: Pearce
authors.forename: L
authors.initials: L
authors.lastname: Morgan
authors.forename: I D
authors.initials: ID
authors.lastname: Bowen
authors.forename: P
authors.initials: P
authors.lastname: Brennan
authors.forename: C
authors.initials: C
authors.lastname: Fegan
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000378:metabolism; D000368:Aged; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000627:therapeutic use*; D017209:Apoptosis; D001241:Aspirin / Q000031:analogs & derivatives*; D019013:CD40 Antigens / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D061945:Caspase Inhibitors; D018920:Coculture Techniques; D051546:Cyclooxygenase 2 / Q000235:genetics; D052246:Cyclooxygenase 2 Inhibitors / Q000737:chemistry / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000188:drug therapy*; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D009842:Oligopeptides / Q000494:pharmacology; D010226:Parabens / Q000737:chemistry / Q000627:therapeutic use*; D020156:Salicylic Acid / Q000737:chemistry / Q000627:therapeutic use*; D051996:Transcription Factor RelA / Q000037:antagonists & inhibitors*; D014158:Transcription, Genetic / Q000187:drug effects; D014407:Tumor Cells, Cultured; D051746:ZAP-70 Protein-Tyrosine Kinase / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D019013:CD40 Antigens; D061945:Caspase Inhibitors; D052246:Cyclooxygenase 2 Inhibitors; D008562:Membrane Glycoproteins; D009842:Oligopeptides; D010226:Parabens; C498143:RELA protein, human; D051996:Transcription Factor RelA; C403754:benzyloxycarbonyl-leucyl-glutamyl-histidyl-aspartic acid fluoromethyl ketone; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D051746:ZAP-70 Protein-Tyrosine Kinase; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1; D053148:Caspase 3; C038193:4-hydroxybenzoic acid; D020156:Salicylic Acid; D001241:Aspirin