title: A High-Throughput Cell-Based Screen Identified a 2-[(E)-2-Phenylvinyl]-8-Quinolinol Core Structure That Activates p53.
abstract: p53 function is frequently inhibited in cancer either through mutations or by increased degradation via MDM2 and/or E6AP E3-ubiquitin ligases. Most agents that restore p53 expression act by binding MDM2 or E6AP to prevent p53 degradation. However, fewer compounds directly bind to and activate p53. Here, we identified compounds that shared a core structure that bound p53, caused nuclear localization of p53 and caused cell death. To identify these compounds, we developed a novel cell-based screen to redirect p53 degradation to the Skip-Cullin-F-box (SCF) ubiquitin ligase complex in cells expressing high levels of p53. In a multiplexed assay, we coupled p53 targeted degradation with Rb1 targeted degradation in order to identify compounds that prevented p53 degradation while not inhibiting degradation through the SCF complex or other proteolytic machinery. High-throughput screening identified several leads that shared a common 2-[(E)-2-phenylvinyl]-8-quinolinol core structure that stabilized p53. Surface plasmon resonance analysis indicated that these compounds bound p53 with a KD of 200 ± 52 nM. Furthermore, these compounds increased p53 nuclear localization and transcription of the p53 target genes PUMA, BAX, p21 and FAS in cancer cells. Although p53-null cells had a 2.5±0.5-fold greater viability compared to p53 wild type cells after treatment with core compounds, loss of p53 did not completely rescue cell viability suggesting that compounds may target both p53-dependent and p53-independent pathways to inhibit cell proliferation. Thus, we present a novel, cell-based high-throughput screen to identify a 2-[(E)-2-phenylvinyl]-8-quinolinol core structure that bound to p53 and increased p53 activity in cancer cells. These compounds may serve as anti-neoplastic agents in part by targeting p53 as well as other potential pathways.
authors.affiliation: Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois, United States of America.
authors.forename: John
authors.initials: J
authors.lastname: Bechill
authors.affiliation: Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois, United States of America.
authors.forename: Rong
authors.initials: R
authors.lastname: Zhong
authors.affiliation: High-throughput Screening Facility, University of Illinois-Champaign Urbana, Champaign, Illinois, United States of America.
authors.forename: Chen
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Biophysics Core Facility, The University of Chicago, Chicago, Illinois, United States of America.
authors.forename: Elena
authors.initials: E
authors.lastname: Solomaha
authors.affiliation: Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois, United States of America.
authors.forename: Michael T
authors.identifier: 0000-0003-4484-462X
authors.initials: MT
authors.lastname: Spiotto
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry* / Q000494:pharmacology; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D006367:HeLa Cells; D057166:High-Throughput Screening Assays; D006801:Humans; D015125:Oxyquinoline / Q000031:analogs & derivatives* / Q000494:pharmacology; D055550:Protein Stability / Q000187:drug effects; D059748:Proteolysis / Q000187:drug effects; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism; D044843:SKP Cullin F-Box Protein Ligases / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D016159:Tumor Suppressor Protein p53 / Q000819:agonists* / Q000235:genetics / Q000378:metabolism; D014753:Vinyl Compounds / Q000737:chemistry* / Q000494:pharmacology; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism; D019014:fas Receptor / Q000235:genetics / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D051017:Apoptosis Regulatory Proteins; C494826:BAX protein, human; C438378:BBC3 protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; C491901:FAS protein, human; D011518:Proto-Oncogene Proteins; D016159:Tumor Suppressor Protein p53; D014753:Vinyl Compounds; D051028:bcl-2-Associated X Protein; D019014:fas Receptor; D015125:Oxyquinoline; D044843:SKP Cullin F-Box Protein Ligases