RESUMO
The design of potent Pin1 inhibitors has been challenging because its active site specifically recognizes a phospho-protein epitope. The de novo design of phosphate-based Pin1 inhibitors focusing on the phosphate recognition pocket and the successful replacement of the phosphate group with a carboxylate have been previously reported. The potency of the carboxylate series is now further improved through structure-based optimization of ligand-protein interactions in the proline binding site which exploits the H-bond interactions necessary for Pin1 catalytic function. Further optimization using a focused library approach led to the discovery of low nanomolar non-phosphate small molecular Pin1 inhibitors. Structural modifications designed to improve cell permeability resulted in Pin1 inhibitors with low micromolar anti-proliferative activities against cancer cells.
Assuntos
Benzimidazóis/farmacologia , Ácidos Carboxílicos/farmacologia , Inibidores Enzimáticos/farmacologia , Peptidilprolil Isomerase/antagonistas & inibidores , Fosfatos/química , Benzimidazóis/síntese química , Benzimidazóis/química , Ácidos Carboxílicos/síntese química , Ácidos Carboxílicos/química , Domínio Catalítico/efeitos dos fármacos , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Estrutura Molecular , Peptidilprolil Isomerase de Interação com NIMA , Peptidilprolil Isomerase/metabolismo , Relação Estrutura-AtividadeRESUMO
The P21-activated kinases (PAK) are emerging antitumor therapeutic targets. In this paper, we describe the discovery of potent PAK inhibitors guided by structure-based drug design. In addition, the efflux of the pyrrolopyrazole series was effectively reduced by applying multiple medicinal chemistry strategies, leading to a series of PAK inhibitors that are orally active in inhibiting tumor growth in vivo.
Assuntos
Antineoplásicos/síntese química , Pirazóis/síntese química , Pirróis/síntese química , Quinases Ativadas por p21/antagonistas & inibidores , Administração Oral , Amidas/síntese química , Amidas/farmacocinética , Amidas/farmacologia , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Carbamatos/química , Carbamatos/farmacocinética , Carbamatos/farmacologia , Cristalografia por Raios X , Cães , Humanos , Ligação de Hidrogênio , Camundongos , Modelos Moleculares , Conformação Molecular , Permeabilidade , Pirazóis/farmacocinética , Pirazóis/farmacologia , Pirróis/farmacocinética , Pirróis/farmacologia , Ratos , Estereoisomerismo , Relação Estrutura-Atividade , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Despite abundant evidence that aberrant Rho-family GTPase activation contributes to most steps of cancer initiation and progression, there is a dearth of inhibitors of their effectors (e.g., p21-activated kinases). Through high-throughput screening and structure-based design, we identify PF-3758309, a potent (K(d) = 2.7 nM), ATP-competitive, pyrrolopyrazole inhibitor of PAK4. In cells, PF-3758309 inhibits phosphorylation of the PAK4 substrate GEF-H1 (IC(50) = 1.3 nM) and anchorage-independent growth of a panel of tumor cell lines (IC(50) = 4.7 +/- 3 nM). The molecular underpinnings of PF-3758309 biological effects were characterized using an integration of traditional and emerging technologies. Crystallographic characterization of the PF-3758309/PAK4 complex defined determinants of potency and kinase selectivity. Global high-content cellular analysis confirms that PF-3758309 modulates known PAK4-dependent signaling nodes and identifies unexpected links to additional pathways (e.g., p53). In tumor models, PF-3758309 inhibits PAK4-dependent pathways in proteomic studies and regulates functional activities related to cell proliferation and survival. PF-3758309 blocks the growth of multiple human tumor xenografts, with a plasma EC(50) value of 0.4 nM in the most sensitive model. This study defines PAK4-related pathways, provides additional support for PAK4 as a therapeutic target with a unique combination of functions (apoptotic, cytoskeletal, cell-cycle), and identifies a potent, orally available small-molecule PAK inhibitor with significant promise for the treatment of human cancers.
Assuntos
Proliferação de Células/efeitos dos fármacos , Modelos Moleculares , Neoplasias/metabolismo , Pirazóis/farmacologia , Pirróis/farmacologia , Transdução de Sinais/efeitos dos fármacos , Quinases Ativadas por p21/antagonistas & inibidores , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cristalografia , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Humanos , Neoplasias/tratamento farmacológico , Fosforilação/efeitos dos fármacos , Pirazóis/química , Pirazóis/metabolismo , Pirróis/química , Pirróis/metabolismo , Fatores de Troca de Nucleotídeo Guanina RhoRESUMO
Following the discovery of a novel series of phosphate-containing small molecular Pin1 inhibitors, the drug design strategy shifted to replacement of the phosphate group with an isostere with potential better pharmaceutical properties. The initial loss in potency of carboxylate analogs was likely due to weaker charge-charge interactions in the putative phosphate binding pocket and was subsequently recovered by structure-based optimization of ligand-protein interactions in the proline binding site, leading to the discovery of a sub-micromolar non-phosphate small molecular Pin1 inhibitor.
Assuntos
Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Peptidilprolil Isomerase/antagonistas & inibidores , Peptidilprolil Isomerase/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Desenho de Fármacos , Humanos , Modelos Moleculares , Peptidilprolil Isomerase de Interação com NIMA , Peptidilprolil Isomerase/química , Ligação Proteica , Relação Estrutura-AtividadeRESUMO
Pin1 is a member of the cis-trans peptidyl-prolyl isomerase family with potential anti-cancer therapeutic value. Here we report structure-based de novo design and optimization of novel Pin1 inhibitors. Without a viable lead from internal screenings, we designed a series of novel Pin1 inhibitors by interrogating and exploring a protein crystal structure of Pin1. The ligand efficiency of the initial concept molecule was optimized with integrated SBDD and parallel chemistry approaches, resulting in a more attractive lead series.
Assuntos
Inibidores Enzimáticos/química , Peptidilprolil Isomerase/antagonistas & inibidores , Sequência de Aminoácidos , Sítios de Ligação , Técnicas de Química Combinatória , Simulação por Computador , Cristalografia por Raios X , Desenho de Fármacos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Humanos , Peptidilprolil Isomerase de Interação com NIMA , Peptidilprolil Isomerase/metabolismo , Relação Estrutura-AtividadeRESUMO
Novel tricyclic benzimidazole carboxamide poly(ADP-ribose) polymerase-1 (PARP-1) inhibitors have been synthesized. Several compounds were found to be powerful chemopotentiators of temozolomide and topotecan in both A549 and LoVo cell lines. In vitro inhibition of PARP-1 was confirmed by direct measurement of NAD+ depletion and ADP-ribose polymer formation caused by chemically induced DNA damage.