title: Nutlin-3 preferentially sensitises wild-type p53-expressing cancer cells to DR5-selective TRAIL over rhTRAIL.
abstract: BACKGROUND
  Tumour cell-selective activation of apoptosis by recombinant human TNF-related apoptosis-inducing ligand (rhTRAIL) is enhanced through co-activation of p53 by chemotherapeutic drugs. The novel anticancer agent nutlin-3 provides a promising alternative for p53 activation by disrupting the interaction between p53 and its negative feedback regulator MDM2.
  
  
  METHODS
  We examined whether nutlin-3 enhances apoptosis induction by rhTRAIL and the DR5-selective TRAIL variant D269H/E195R in wild-type p53-expressing ovarian, colon and lung cancer cell lines and in an ex vivo model of human ovarian cancer.
  
  
  RESULTS
  Nutlin-3 enhanced p53, p21, MDM2 and DR5 surface expression. Although nutlin-3 did not induce apoptosis, it preferentially enhanced D269H/E195R-induced apoptosis over rhTRAIL. Combination treatment potentiated the cleavage of caspases 8, 9, 3 and PARP. P53 and MDM2 siRNA experiments showed that this enhanced apoptotic effect was mediated by wild-type p53. Indeed, nutlin-3 did not enhance rhTRAIL-induced apoptosis in OVCAR-3 cells harbouring mutant p53. Addition of the chemotherapeutic drug cisplatin to the combination further increased p53 and DR5 levels and rhTRAIL- and D269H/E195R-induced apoptosis. As a proof of concept, we show that the combination of D269H/E195R, nutlin-3 and cisplatin induced massive apoptosis in ex vivo tissue slices of primary human ovarian cancers.
  
  
  CONCLUSIONS
  Nutlin-3 is a potent enhancer of D269H/E195R-induced apoptosis in wild-type p53-expressing cancer cells. Addition of DNA-damaging agents such as cisplatin further enhances DR5-mediated apoptosis.
authors.affiliation: Department of Medical Oncology, Cancer Research Center Groningen, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Meijer
authors.forename: F A E
authors.initials: FA
authors.lastname: Kruyt
authors.forename: A G J
authors.initials: AG
authors.lastname: van der Zee
authors.forename: H
authors.initials: H
authors.lastname: Hollema
authors.forename: P
authors.initials: P
authors.lastname: Le
authors.forename: K A
authors.initials: KA
authors.lastname: ten Hoor
authors.forename: G M M
authors.initials: GM
authors.lastname: Groothuis
authors.forename: W J
authors.initials: WJ
authors.lastname: Quax
authors.forename: E G E
authors.initials: EG
authors.lastname: de Vries
authors.forename: S
authors.initials: S
authors.lastname: de Jong
mesh_terms: D019943:Amino Acid Substitution; D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D019008:Drug Resistance, Neoplasm / Q000187:drug effects / Q000235:genetics; D004357:Drug Synergism; D016158:Genes, p53; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology*; D009369:Neoplasms / Q000235:genetics / Q000473:pathology*; D010879:Piperazines / Q000494:pharmacology*; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000819:agonists* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000494:pharmacology*; D013379:Substrate Specificity; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000235:genetics / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D007093:Imidazoles; D010879:Piperazines; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D011994:Recombinant Proteins; D053221:TNF-Related Apoptosis-Inducing Ligand; C482205:nutlin 3