RESUMO
Methionine aminopeptidase-2 (MetAP2) is a novel target for cancer therapy. As part of an effort to discover orally active reversible inhibitors of MetAP2, a series of anthranilic acid sulfonamides with micromolar affinities for human MetAP2 were identified using affinity selection by mass spectrometry (ASMS) screening. These micromolar hits were rapidly improved to nanomolar leads on the basis of insights from protein crystallography; however, the compounds displayed extensive binding to human serum albumin and had limited activity in cellular assays. Modifications based on structural information on the binding of lead compounds to both MetAP2 and domain III of albumin allowed the identification of compounds with significant improvements in both parameters, which showed good cellular activity in both proliferation and methionine processing assays.
Assuntos
Aminopeptidases/química , Antineoplásicos/síntese química , Metaloendopeptidases/química , Albumina Sérica/química , Sulfonamidas/síntese química , ortoaminobenzoatos/síntese química , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Técnicas In Vitro , Espectrometria de Massas , Metionina/metabolismo , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Estrutura Terciária de Proteína , Ratos , Relação Estrutura-Atividade , Sulfonamidas/química , Sulfonamidas/farmacologia , ortoaminobenzoatos/química , ortoaminobenzoatos/farmacologiaRESUMO
We have screened molecules for inhibition of MetAP2 as a novel approach toward antiangiogenesis and anticancer therapy using affinity selection/mass spectrometry (ASMS) employing MetAP2 loaded with Mn(2+) as the active site metal. After a series of anthranilic acid sulfonamides with micromolar affinities was identified, chemistry efforts were initiated. The micromolar hits were quickly improved to potent nanomolar inhibitors by chemical modifications guided by insights from X-ray crystallography.
Assuntos
Aminopeptidases/antagonistas & inibidores , Inibidores da Angiogênese/farmacologia , Antineoplásicos/farmacologia , Glicoproteínas/antagonistas & inibidores , Sulfonamidas/farmacologia , Inibidores da Angiogênese/síntese química , Inibidores da Angiogênese/química , Antineoplásicos/síntese química , Antineoplásicos/química , Sítios de Ligação , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Manganês/química , Espectrometria de Massas/métodos , Metionil Aminopeptidases , Modelos Moleculares , Estrutura Molecular , Sensibilidade e Especificidade , Estereoisomerismo , Relação Estrutura-Atividade , Sulfonamidas/síntese química , Sulfonamidas/químicaRESUMO
Methionine aminopeptidase (MetAP)-2 has been suggested as a novel target for cancer therapy because the anticancer agent TNP-470 irreversibly inactivates the catalytic activity of this enzyme. However, the importance of MetAP2 in cell growth and tumor progression was uncertain because previous data were based on the chemically reactive TNP-470. Here we show that a rationally designed reversible MetAP2 inhibitor, A-357300, suppresses tumor growth preclinically without the toxicities observed with TNP-470. We have synthesized this bestatin-type MetAP2 inhibitor with the aid of crystal structures of the enzyme-inhibitor complexes and parallel synthesis. A-357300 induces cytostasis by cell cycle arrest at the G(1) phase selectively in endothelial cells and in a subset of tumor cells, but not in most primary cells of nonendothelial type. A-357300 inhibits angiogenesis both in vitro and in vivo and shows potent antitumor efficacy in carcinoma, sarcoma, and neuroblastoma murine models. These data affirm that MetAP2 plays a pivotal role in cell growth and establish that reversible MetAP2 inhibitors are promising novel cancer therapeutic agents.