RESUMO
Activation of the PI3K/Akt/mTOR kinase pathway is associated with human cancers. A dual p70S6K/Akt inhibitor is sufficient to inhibit strong tumor growth and to block negative impact of the compensatory Akt feedback loop activation. A scaffold docking strategy based on an existing quinazoline carboxamide series identified 4-aminopyrimidine analog 6, which showed a single-digit nanomolar and a micromolar potencies in p70S6K and Akt enzymatic assays. SAR optimization improved Akt enzymatic and p70S6K cellular potencies, reduced hERG liability, and ultimately discovered the promising candidate 37, which exhibited with a single digit nanomolar value in both p70S6K and Akt biochemical assays, and hERG activities (IC50 = 17.4 µM). This agent demonstrated dose-dependent efficacy in inhibiting mice breast cancer tumor growth and covered more than 90% pS6 inhibition up to 24 h at a dose of 200 mg/kg po.
Assuntos
Antineoplásicos/farmacologia , Descoberta de Drogas , Neoplasias Mamárias Animais/tratamento farmacológico , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Pirimidinas/farmacologia , Proteínas Quinases S6 Ribossômicas 70-kDa/antagonistas & inibidores , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Área Sob a Curva , Cães , Feminino , Meia-Vida , Haplorrinos , Camundongos , Simulação de Acoplamento Molecular , Estrutura Molecular , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Pirimidinas/química , Pirimidinas/farmacocinética , Ratos , Proteínas Quinases S6 Ribossômicas 70-kDa/genética , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Relação Estrutura-Atividade , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismoRESUMO
Bruton's tyrosine kinase (Btk) is a member of the Tec kinase family that is expressed in cells of hematopoietic lineage (e.g. B cells, macrophages, monocytes, and mast cells). Small molecule covalent irreversible Btk inhibitors targeting Cys481 within the ATP-binding pocket have been applied in the treatment of B-cell malignancies. Starting from a fragment, we discovered a novel series of potent covalent irreversible Btk inhibitors that bear N-linked groups occupying the solvent accessible pocket (SAP) of the active site of the Btk kinase domain. The hit molecules, however, displayed high P-gp mediated efflux ratio (ER) and poor A-B permeability in Caco-2 assay. By decreasing tPSA, installing steric hindrance and adjusting clogP, one top molecule 9 was discovered, which showed a 99% decrease in efflux ratio and a 90-fold increase in A-B permeability compared to hit molecule 1.