title: The mutant p53-conformation modifying drug, CP-31398, can induce apoptosis of human cancer cells and can stabilize wild-type p53 protein.
abstract: CP-31398, a styrylquinazoline, emerged from a screen for therapeutic agents that restore a wild-type DNA-binding conformation of mutant p53 to suppress tumors in-vivo (Science 286, 2507, 1999). We investigated the growth inhibitory mechanism of CP-31398 using nine human cancer cell lines containing wild-type, mutant or no p53 expression. Six of nine cell lines underwent apoptosis after exposure to CP-31398, while two cell lines, DLD1 colon cancer and H460 lung cancer, underwent exclusively cell cycle arrest. Cell cycle arrest preceded the apoptosis in some cases. CP-31398 did not inhibit growth of the p53 non-expressing ovarian cancer cell line SKOV3. Interestingly, we found that wild-type p53 protein is stabilized upon CP-31398 exposure. p53 target genes such as p21WAF1/Cip1, and KILLER/DR5 were upregulated by CP-31398, but their expression did not correlate with arrest or apoptosis induction. Combination of CP-31398 and TRAIL or chemotherapeutic agents enhanced cancer cell killing effect possibly through upregulation of p53-regulated genes such as KILLER/DR5. Bax-/-, wild-type p53-expressing cells displayed reduced susceptibility to killing by CP-31398. An Affymetrix GeneChip Array screen revealed that CP-31398 alters expression of non-p53 target genes in addition to p53-responsive genes. Although our preliminary data suggest that CP-31398 does not alter wild-type p53:MDM2 interaction, further efforts are required to elucidate the mechanism of wild-type p53 stabilization by CP-31398. The results increase our understanding of CP-31398 action, and suggest strategies for improving its specificity, possibly through use of microarrays to screen related compounds with higher mutant p53-specificity.
authors.affiliation: Howard Hughes Medical Institute, Departments of Medicine, Genetics, Pharmacology and Cancer Center, University of Pennsylvania School of Medicine, 415 Curie Boulevard, CRB 437A, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Rishu
authors.initials: R
authors.lastname: Takimoto
authors.forename: Wenge
authors.initials: W
authors.lastname: Wang
authors.forename: David T
authors.initials: DT
authors.lastname: Dicker
authors.forename: Farzan
authors.initials: F
authors.lastname: Rastinejad
authors.forename: Joseph
authors.initials: J
authors.lastname: Lyssikatos
authors.forename: Wafik S
authors.initials: WS
authors.lastname: el-Deiry
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000096:biosynthesis / Q000235:genetics; D003513:Cycloheximide / Q000494:pharmacology; D004273:DNA, Neoplasm / Q000378:metabolism; D004317:Doxorubicin / Q000494:pharmacology; D005260:Female; D016193:G1 Phase / Q000187:drug effects; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D016158:Genes, p53; D006131:Growth Inhibitors / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000494:pharmacology; D009363:Neoplasm Proteins / Q000737:chemistry / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D009687:Nuclear Proteins; D011485:Protein Binding / Q000187:drug effects; D011487:Protein Conformation / Q000187:drug effects; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051736:Proto-Oncogene Proteins c-mdm2; D011743:Pyrimidines / Q000494:pharmacology*; D016160:Retinoblastoma Protein / Q000096:biosynthesis / Q000235:genetics; D053221:TNF-Related Apoptosis-Inducing Ligand; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000187:drug effects* / Q000502:physiology
chemical_list: D000970:Antineoplastic Agents; D051017:Apoptosis Regulatory Proteins; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D004273:DNA, Neoplasm; D006131:Growth Inhibitors; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D011743:Pyrimidines; D016160:Retinoblastoma Protein; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; D016159:Tumor Suppressor Protein p53; D004317:Doxorubicin; D003513:Cycloheximide; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2; C402665:CP 31398