ABSTRACT
Complement activation has been implicated in disease states such as hereditary angioedema, ischemia-reperfusion injury, acute respiratory distress syndrome, and acute transplant rejection. Even though the complement cascade provides several protein targets for potential therapeutic intervention only two complement inhibitors have been approved so far for clinical use including anti-C5 antibodies for the treatment of paroxysmal nocturnal hemoglobinuria and purified C1-esterase inhibitor replacement therapy for the control of hereditary angioedema flares. In the present study, optimization of potency and physicochemical properties of a series of thiophene amidine-based C1s inhibitors with potential utility as intravenous agents for the inhibition of the classical pathway of complement is described.
Subject(s)
Complement C1s/antagonists & inhibitors , Heterocyclic Compounds/chemistry , Heterocyclic Compounds/pharmacology , Animals , Binding Sites , Half-Life , Models, Molecular , Molecular Structure , Rats , Structure-Activity RelationshipABSTRACT
The disruption of the p53-Hdm2 protein-protein interaction induces cell growth arrest and apoptosis. We have identified the 1,4-benzodiazepine-2,5-dione scaffold as a suitable template for inhibiting this interaction by binding to the Hdm2 protein. Several compounds have been made with improved potency, solubility, and cell-based activities.
Subject(s)
Benzodiazepines/pharmacology , Proto-Oncogene Proteins c-mdm2/antagonists & inhibitors , Apoptosis/drug effects , Benzodiazepines/chemical synthesis , Benzodiazepines/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Screening Assays, Antitumor , Humans , Molecular Structure , Protein Binding/drug effects , Proto-Oncogene Proteins c-mdm2/metabolism , Stereoisomerism , Structure-Activity Relationship , Tumor Suppressor Protein p53/antagonists & inhibitors , Tumor Suppressor Protein p53/metabolismABSTRACT
The 1,4-benzodiazepine-2,5-dione is a suitable template to disrupt the interaction between p53 and Hdm2. The development of an enantioselective synthesis disclosed the stereochemistry of the active enantiomer. An in vitro p53 peptide displacement assay identified active compounds. These activities were confirmed in several cell-based assays including induction of the p53 regulated gene (PIG-3) and caspase activity.
Subject(s)
Benzodiazepines/chemistry , Benzodiazepines/pharmacology , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Proto-Oncogene Proteins c-mdm2/antagonists & inhibitors , Benzodiazepines/chemical synthesis , Caspases/metabolism , Cell Line, Tumor , Crystallography, X-Ray , Enzyme Inhibitors/chemistry , Humans , Hydrogen Bonding , Models, Molecular , Molecular Structure , Mutation/genetics , Proto-Oncogene Proteins c-mdm2/chemistry , Proto-Oncogene Proteins c-mdm2/metabolism , Stereoisomerism , Structure-Activity Relationship , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolismABSTRACT
The activity and stability of the p53 tumor suppressor are regulated by the human homologue of the mouse double minute 2 (Hdm2) oncoprotein. It has been hypothesized that small molecules disrupting the Hdm2:p53 complex would allow for the activation of p53 and result in growth suppression. We have identified small-molecule inhibitors of the Hdm2:p53 interaction using our proprietary ThermoFluor microcalorimetry technology. Medicinal chemistry and structure-based drug design led to the development of an optimized series of benzodiazepinediones, including TDP521252 and TDP665759. Activities were dependent on the expression of wild-type (wt) p53 and Hdm2 as determined by lack of potency in mutant or null p53-expressing cell lines or cells engineered to no longer express Hdm2 and wt p53. TDP521252 and TDP665759 inhibited the proliferation of wt p53-expressing cell lines with average IC(50)s of 14 and 0.7 micromol/L, respectively. These results correlated with the direct cellular dissociation of Hdm2 from wt p53 observed within 15 minutes in JAR choriocarcinoma cells. Additional activities of these inhibitors in vitro include stabilization of p53 protein levels, up-regulation of p53 target genes in a DNA damage-independent manner, and induction of apoptosis in HepG2 cells. Administration of TDP665759 to mice led to an increase in p21(waf1/cip1) levels in liver samples. Finally, TDP665759 synergizes with doxorubicin both in culture and in an A375 xenograft model to decrease tumor growth. Taken together, these data support the potential utility of small-molecule inhibitors of the Hdm2:p53 interaction for the treatment of wt p53-expressing tumors.
Subject(s)
Benzodiazepinones/pharmacology , Doxorubicin/pharmacology , Proto-Oncogene Proteins c-mdm2/drug effects , Tumor Suppressor Protein p53/drug effects , Animals , Antineoplastic Combined Chemotherapy Protocols , Apoptosis/drug effects , Benzodiazepines/chemistry , Benzodiazepines/pharmacology , Benzodiazepinones/administration & dosage , Cell Line, Tumor , Cell Proliferation/drug effects , Doxorubicin/administration & dosage , Drug Screening Assays, Antitumor , Drug Synergism , Female , Humans , Liver Neoplasms, Experimental/drug therapy , Liver Neoplasms, Experimental/metabolism , Mice , Mice, Nude , Multiprotein Complexes , Mutation , Proto-Oncogene Proteins c-mdm2/metabolism , Tumor Cells, Cultured , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Xenograft Model Antitumor AssaysABSTRACT
We describe the synthesis and structure/activity relationship of RGD mimetics that are potent inhibitors of the integrin alpha(v)beta3. Indol-1-yl propionic acids containing a variety of basic moieties at the 5-position, as well as substitutions alpha and beta to the carboxy terminus were synthesized and evaluated. Novel compounds with improved potency have been identified.
