RESUMO
The discovery of aurora kinases as essential regulators of cell division has led to intense interest in identifying small molecule aurora kinase inhibitors for the potential treatment of cancer. A high-throughput screening effort identified pyridinyl-pyrimidine 6a as a moderately potent dual inhibitor of aurora kinases -A and -B. Optimization of this hit resulted in an anthranilamide lead (6j) that possessed improved enzyme and cellular activity and exhibited a high level of kinase selectivity. However, this anthranilamide and subsequent analogues suffered from a lack of oral bioavailability. Converting the internally hydrogen-bonded six-membered pseudo-ring of the anthranilamide to a phthalazine (8a-b) led to a dramatic improvement in oral bioavailability (38-61%F) while maintaining the potency and selectivity characteristics of the anthranilamide series. In a COLO 205 tumor pharmacodynamic assay measuring phosphorylation of the aurora-B substrate histone H3 at serine 10 (p-histone H3), oral administration of 8b at 50 mg/kg demonstrated significant reduction in tumor p-histone H3 for at least 6 h.
Assuntos
Antineoplásicos/síntese química , Ftalazinas/síntese química , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Piridinas/síntese química , Pirimidinas/síntese química , Administração Oral , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Aurora Quinase B , Aurora Quinases , Disponibilidade Biológica , Proteínas Sanguíneas/metabolismo , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Histonas/metabolismo , Humanos , Técnicas In Vitro , Masculino , Camundongos , Camundongos Nus , Microssomos Hepáticos/metabolismo , Modelos Moleculares , Transplante de Neoplasias , Ftalazinas/farmacocinética , Ftalazinas/farmacologia , Ligação Proteica , Piridinas/farmacocinética , Piridinas/farmacologia , Pirimidinas/farmacocinética , Pirimidinas/farmacologia , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Transplante HeterólogoRESUMO
Inhibition of angiogenesis is a promising and clinically validated approach for limiting tumor growth and survival. The receptor tyrosine kinase Tie-2 is expressed almost exclusively in the vascular endothelium and is required for developmental angiogenesis and vessel maturation. However, the significance of Tie-2 signaling in tumor angiogenesis is not well understood. In order to evaluate the therapeutic utility of inhibiting Tie-2 signaling, we developed a series of potent and orally bioavailable small molecule Tie-2 kinase inhibitors with selectivity over other kinases, especially those that are believed to be important for tumor angiogenesis. Our earlier work provided pyridinyl pyrimidine 6 as a potent, nonselective Tie-2 inhibitor that was designed on the basis of X-ray cocrystal structures of KDR inhibitors 34 (triazine) and 35 (nicotinamide). Lead optimization resulted in pyridinyl triazine 63, which exhibited >30-fold selectivity over a panel of kinases, good oral exposure, and in vivo inhibition of Tie-2 phosphorylation.
Assuntos
Inibidores da Angiogênese/síntese química , Benzamidas/síntese química , Piridinas/síntese química , Receptor TIE-2/antagonistas & inibidores , Triazinas/síntese química , Administração Oral , Inibidores da Angiogênese/farmacocinética , Inibidores da Angiogênese/farmacologia , Animais , Benzamidas/farmacocinética , Benzamidas/farmacologia , Sítios de Ligação , Proteínas Sanguíneas/metabolismo , Cristalografia por Raios X , Feminino , Humanos , Injeções Intraperitoneais , Injeções Intravenosas , Masculino , Camundongos , Modelos Moleculares , Estrutura Molecular , Fosforilação , Ligação Proteica , Piridinas/farmacocinética , Piridinas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor TIE-2/química , Receptor TIE-2/metabolismo , Relação Estrutura-Atividade , Triazinas/farmacocinética , Triazinas/farmacologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidoresRESUMO
The lymphocyte-specific kinase (Lck) is a cytoplasmic tyrosine kinase of the Src family expressed in T cells and natural killer (NK) cells. Genetic evidence in both mice and humans demonstrates that Lck kinase activity is critical for signaling mediated by the T cell receptor (TCR), which leads to normal T cell development and activation. Selective inhibition of Lck is expected to offer a new therapy for the treatment of T-cell-mediated autoimmune and inflammatory disease. Screening of our kinase-preferred collection identified aminoquinazoline 1 as a potent, nonselective inhibitor of Lck and T cell proliferation. In this report, we describe the synthesis and structure-activity relationships of a series of novel aminoquinazolines possessing in vitro mechanism-based potency. Optimized, orally bioavailable compounds 32 and 47 exhibit anti-inflammatory activity (ED(50) of 22 and 11 mg/kg, respectively) in the anti-CD3-induced production of interleukin-2 (IL-2) in mice.