title: Therapeutic reactivation of mutant p53 protein by quinazoline derivatives.
abstract: OBJECTIVE
  The human tumour suppressor protein p53 is mutated in nearly half of human tumours and most mutant proteins have single amino acid changes. Several drugs including the quinazoline derivative 1 (CP-31398) have been reported to restore p53 activity in mutant cells. The side chain of 1 contains a styryl linkage that compromises its stability and we wished to explore the activity of analogues containing more stable side chains.
  
  
  METHODS
  Reactivation of p53 function was measured by flow cytometry as the ability to potentiate radiation-induced G(1)-phase cell cycle arrest and by western blotting to determine expression of p21(WAF1). DNA binding was measured by competition with ethidium and preliminary pharmacological and xenograft studies were carried out.
  
  
  RESULTS
  Screening of analogues for potentiation of radiation-induced G(1)-phase cell cycle arrest using NZOV11, an ovarian tumour cell line containing a p53(R248Q) mutation, demonstrated that the (2-benzofuranyl)-quinazoline derivative 5 was among the most active of the analogues. Compound 5 showed similar effects in several other p53 mutant human tumour cell lines but not in a p53 null cell line. 5 also potentiated p21(WAF1) expression induced by radiation. DNA binding affinity was measured and found to correlate with p53 reactivation activity. Plasma concentrations of 5 in mice were sufficient to suggest in vivo activity and a small induced tumour growth delay (7 days) of NZM4 melanoma xenografts was observed.
  
  
  CONCLUSIONS
  Compound 5 restores p53-like function to a human tumour cells lines expressing a variety of mutant p53 proteins, thus providing a basis for the design of further new drugs.
authors.affiliation: Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
authors.forename: Hamish S
authors.initials: HS
authors.lastname: Sutherland
authors.forename: In Young
authors.initials: IY
authors.lastname: Hwang
authors.forename: Elaine S
authors.initials: ES
authors.lastname: Marshall
authors.forename: Brent S
authors.initials: BS
authors.lastname: Lindsay
authors.forename: William A
authors.initials: WA
authors.lastname: Denny
authors.forename: Catherine
authors.initials: C
authors.lastname: Gilchrist
authors.forename: Wayne R
authors.initials: WR
authors.lastname: Joseph
authors.forename: Debra
authors.initials: D
authors.lastname: Greenhalgh
authors.forename: Emma
authors.initials: E
authors.lastname: Richardson
authors.forename: Philip
authors.initials: P
authors.lastname: Kestell
authors.forename: Angela
authors.initials: A
authors.lastname: Ding
authors.forename: Bruce C
authors.initials: BC
authors.lastname: Baguley
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000187:drug effects / Q000235:genetics; D045744:Cell Line, Tumor; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics / Q000378:metabolism; D004250:DNA Topoisomerases, Type II / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D051379:Mice; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000187:drug effects*; D011799:Quinazolines / Q000494:pharmacology*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics* / Q000378:metabolism*
chemical_list: D050759:Cyclin-Dependent Kinase Inhibitor p21; D004268:DNA-Binding Proteins; D050505:Mutant Proteins; D011799:Quinazolines; D016159:Tumor Suppressor Protein p53; D004250:DNA Topoisomerases, Type II