Structure-based design, synthesis, and biological evaluation of novel 1,4-diazepines as HDM2 antagonists.

Crystallographic analysis of ligands bound to HDM2 suggested that 7-substituted 1,4-diazepine-2,5-diones could mimic the alpha-helix of p53 peptide and may represent a promising scaffold to develop HDM2-p53 antagonists. To verify this hypothesis, we synthesized and biologically evaluated 5-[(3S)-3-(4-chlorophenyl)-4-[(R)-1-(4-chlorophenyl)ethyl]-2,5-dioxo-7-phenyl-1,4-diazepin-1-yl]valeric acid (10) and 5-[(3S)-7-(2-bromophenyl)-3-(4-chlorophenyl)-4-[(R)-1-(4-chlorophenyl)ethyl]-2,5-dioxo-1,4-diazepin-1-yl]valeric acid (11). Preliminary in vitro testing shows that 10 and 11 substantially antagonize the binding between HDM2 and p53 with an IC(50) of 13 and 3.6 microM, respectively, validating the modeling predictions. Taken together with the high cell permeability of diazepine 11 determined in CACO-2 cells, these results suggest that 1,4-diazepine-2,5-diones may be useful in the treatment of certain cancers.

[1]  Keisuke Konishi,et al.  New and better protocols for a short-term Caco-2 cell culture system. , 2002, Journal of pharmaceutical sciences.

[2]  P. Artursson,et al.  Correlation between oral drug absorption in humans and apparent drug permeability coefficients in human intestinal epithelial (Caco-2) cells. , 1991, Biochemical and biophysical research communications.

[3]  Maxwell D Cummings,et al.  Discovery and cocrystal structure of benzodiazepinedione HDM2 antagonists that activate p53 in cells. , 2005, Journal of medicinal chemistry.

[4]  Victor S. Lobanov,et al.  High-Density Miniaturized Thermal Shift Assays as a General Strategy for Drug Discovery , 2001 .

[5]  D. Fabbro,et al.  A small synthetic peptide, which inhibits the p53-hdm2 interaction, stimulates the p53 pathway in tumour cell lines. , 2000, Journal of molecular biology.

[6]  A. Levine,et al.  Structure of the MDM2 Oncoprotein Bound to the p53 Tumor Suppressor Transactivation Domain , 1996, Science.

[7]  Hitoshi Sezaki,et al.  Analysis of Drug Permeation Across Caco-2 Monolayer: Implication for Predicting In Vivo Drug Absorption , 1997, Pharmaceutical Research.

[8]  Hirofumi Tanaka,et al.  Oncoprotein MDM2 is a ubiquitin ligase E3 for tumor suppressor p53 , 1997, FEBS letters.

[9]  M. Oren,et al.  Cell type‐specific inhibition of p53‐mediated apoptosis by mdm2. , 1996, The EMBO journal.

[10]  B. Vogelstein,et al.  p53 mutations in human cancers. , 1991, Science.

[11]  V. Adler,et al.  Mdm2 association with p53 targets its ubiquitination , 1998, Oncogene.

[12]  T. N. Bhat,et al.  The Protein Data Bank , 2000, Nucleic Acids Res..

[13]  Stephen N. Jones,et al.  Regulation of p53 stability by Mdm2 , 1997, Nature.

[14]  Maxwell D Cummings,et al.  1,4-Benzodiazepine-2,5-diones as small molecule antagonists of the HDM2-p53 interaction: discovery and SAR. , 2005, Bioorganic & medicinal chemistry letters.

[15]  S. Kay,et al.  Functional interaction of phytochrome B and cryptochrome 2 , 2000, Nature.

[16]  W. Rubas,et al.  Comparison of the Permeability Characteristics of a Human Colonic Epithelial (Caco-2) Cell Line to Colon of Rabbit, Monkey, and Dog Intestine and Human Drug Absorption , 2004, Pharmaceutical Research.

[17]  R. Honda,et al.  Activity of MDM2, a ubiquitin ligase, toward p53 or itself is dependent on the RING finger domain of the ligase , 2000, Oncogene.

[18]  A. Levine,et al.  Surfing the p53 network , 2000, Nature.

[19]  A. Levine.  p53, the Cellular Gatekeeper for Growth and Division , 1997, Cell.