RESUMEN
Systematic variations of the xanthine scaffold in close analogs of development compound BI 1356 led to the class of 3,5-dihydro-imidazo[4,5-d]pyridazin-4-ones which provided, after substituent screening, a series of highly potent DPP-4 inhibitors.
Asunto(s)
Inhibidores de la Dipeptidil-Peptidasa IV , Purinas/síntesis química , Purinas/farmacología , Piridazinas/síntesis química , Piridazinas/farmacología , Quinazolinas/síntesis química , Quinazolinas/farmacología , Técnicas Químicas Combinatorias , Humanos , Linagliptina , Estructura Molecular , Purinas/química , Piridazinas/química , Quinazolinas/química , Relación Estructura-ActividadRESUMEN
BI 1356 [proposed trade name ONDERO; (R)-8-(3-amino-piperidin-1-yl)-7-but-2-ynyl-3-methyl-1-(4-methyl-quinazolin-2-ylmethyl)-3,7-dihydro-purine-2,6-dione] is a novel dipeptidyl peptidase (DPP)-4 inhibitor under clinical development for the treatment of type 2 diabetes. In this study, we investigated the potency, selectivity, mechanism, and duration of action of BI 1356 in vitro and in vivo and compared it with other DPP-4 inhibitors. BI 1356 inhibited DPP-4 activity in vitro with an IC(50) of approximately 1 nM, compared with sitagliptin (19 nM), alogliptin (24 nM), saxagliptin (50 nM), and vildagliptin (62 nM). BI 1356 was a competitive inhibitor, with a K(i) of 1 nM. The calculated k(off) rate for BI 1356 was 3.0 x 10(-5)/s (versus 2.1 x 10(-4)/s for vildagliptin). BI 1356 was >/=10,000-fold more selective for DPP-4 than DPP-8, DPP-9, amino-peptidases N and P, prolyloligopeptidase, trypsin, plasmin, and thrombin and was 90-fold more selective than for fibroblast activation protein in vitro. In HanWistar rats, the DPP-4 inhibition 24 h after administration of BI 1356 was more profound than with any of the other DPP-4 inhibitors. In C57BL/6J mice and Zucker fatty (fa/fa) rats, the duration of action on glucose tolerance decreased in the order BI 1356 > (sitagliptin/saxagliptin) > vildagliptin. These effects were mediated through control of glucagon-like peptide-1 and insulin. In conclusion, BI 1356 inhibited DPP-4 more effectively than vildagliptin, sitagliptin, saxagliptin, and alogliptin and has the potential to become the first truly once-a-day DPP-4 inhibitor for the treatment of type 2 diabetes.
Asunto(s)
Inhibidores de la Dipeptidil-Peptidasa IV , Hipoglucemiantes/farmacocinética , Inhibidores de Proteasas/farmacocinética , Purinas/farmacocinética , Quinazolinas/farmacocinética , Animales , Antígenos de Neoplasias , Biomarcadores de Tumor/antagonistas & inhibidores , Células CACO-2 , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Dipeptidil Peptidasa 4 , Endopeptidasas , Gelatinasas , Humanos , Concentración 50 Inhibidora , Linagliptina , Masculino , Proteínas de la Membrana , Ratones , Purinas/farmacología , Quinazolinas/farmacología , Ratas , Ratas Wistar , Ratas Zucker , Serina Endopeptidasas , XantinasRESUMEN
Disrupting the interaction between glycogen phosphorylase and the glycogen targeting subunit (G(L)) of protein phosphatase 1 is emerging as a novel target for the treatment of type 2 diabetes. To elucidate the molecular basis of binding, we have determined the crystal structure of liver phosphorylase bound to a G(L)-derived peptide. The structure reveals the C terminus of G(L) binding in a hydrophobically collapsed conformation to the allosteric regulator-binding site at the phosphorylase dimer interface. G(L) mimics interactions that are otherwise employed by the activator AMP. Functional studies show that G(L) binds tighter than AMP and confirm that the C-terminal Tyr-Tyr motif is the major determinant for G(L) binding potency. Our study validates the G(L)-phosphorylase interface as a novel target for small molecule interaction.
Asunto(s)
Glucógeno Fosforilasa de Forma Hepática/química , Péptidos/química , Proteína Fosfatasa 1/química , Adenosina Monofosfato/química , Adenosina Monofosfato/metabolismo , Secuencias de Aminoácidos/fisiología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/enzimología , Dimerización , Glucógeno Fosforilasa de Forma Hepática/metabolismo , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Péptidos/metabolismo , Unión Proteica/fisiología , Proteína Fosfatasa 1/metabolismo , Estructura Cuaternaria de Proteína/fisiología , Subunidades de Proteína/química , Subunidades de Proteína/metabolismoRESUMEN
A new chemical class of potent DPP-4 inhibitors structurally derived from the xanthine scaffold for the treatment of type 2 diabetes has been discovered and evaluated. Systematic structural variations have led to 1 (BI 1356), a highly potent, selective, long-acting, and orally active DPP-4 inhibitor that shows considerable blood glucose lowering in different animal species. 1 is currently undergoing clinical phase IIb trials and holds the potential for once-daily treatment of type 2 diabetics.
Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Inhibidores de la Dipeptidil-Peptidasa IV , Hipoglucemiantes/síntesis química , Piperidinas/síntesis química , Purinas/síntesis química , Quinazolinas/síntesis química , Administración Oral , Animales , Células CACO-2 , Cristalografía por Rayos X , Dipeptidil Peptidasa 4 , Perros , Humanos , Hipoglucemiantes/farmacocinética , Hipoglucemiantes/farmacología , Linagliptina , Macaca fascicularis , Macaca mulatta , Masculino , Modelos Moleculares , Piperidinas/farmacocinética , Piperidinas/farmacología , Purinas/farmacocinética , Purinas/farmacología , Quinazolinas/farmacocinética , Quinazolinas/farmacología , Ratas , Ratas Wistar , Estereoisomerismo , Relación Estructura-ActividadRESUMEN
Overexpression of the epidermal growth factor receptors (EGFRs) and human epidermal growth factor receptor 2 occurs frequently in human cancers and is associated with aggressive tumor behavior and poor patient prognosis. We have investigated the effects in vitro and in vivo of a new class of inhibitor molecules on the growth of several human cancer cell lines. BIBX1382 [N8-(3-chloro-4-fluoro-phenyl)-N2-(1-methyl-piperidin-4-yl)-pyrimido[5,4-d]pyrimidine-2,8-diamine] and BIBU1361 [(3-chloro-4-fluoro-phenyl)-[6-(4-diethylaminomethyl-piperidin-1yl)-pyrimido[5,4-d]pyrimidin-4-yl]-amine] are two new selective EGFR kinase inhibitors that do not block the activity of other tyrosine kinases. BIBU1361 blocked epidermal growth factor-induced phosphorylation of EGFR and also prevented downstream responses such as mitogen-activated protein kinase kinase (MAPK/extracellular signal-regulated kinase kinase) and MAPK activation in cells. In accordance with these observations thymidine incorporation into EGFR-expressing KB cells was selectively and potently inhibited by BIBX1382 and BIBU1361 with half-maximally effective doses in the nanomolar range. Oral administration of these compounds inhibited the growth of established human xenografts in athymic mice, including vulval and head and neck squamous cell carcinomas. Tumor growth inhibition by BIBX1382 coincided with reduced pEGFR and Ki-67 levels in vivo, which is in accordance with the expected effect of EGFR inhibitors. Collectively, these results show that the structural class of pyrimidopyrimidines, exemplified here by BIBX1382 and BIBU1361, represents an interesting scaffold for the design of EGFR inhibitors.
Asunto(s)
Antineoplásicos/farmacología , Receptores ErbB/antagonistas & inhibidores , Compuestos Orgánicos/farmacología , Animales , Antineoplásicos/uso terapéutico , Modelos Animales de Enfermedad , Receptores ErbB/metabolismo , Femenino , Humanos , Células KB , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Compuestos Orgánicos/uso terapéutico , Fosforilación , Piperidinas/farmacología , Piperidinas/uso terapéutico , Pirimidinas/farmacología , Pirimidinas/uso terapéutico , Transducción de Señal/efectos de los fármacos , Células Tumorales Cultivadas , Vulva/patología , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Several signalling pathways contribute to the regulation of epithelial to mesenchymal transition (EMT), either during developmentally regulated processes or in cancer progression and metastasis. Induction of EMT in fully polarized mouse mammary epithelial cells (EpH4) by an inducible c-fos estrogen receptor (FosER) oncoprotein involves loss of E-cadherin expression, nuclear translocation of beta-catenin, and autocrine production of TGFbeta. Reporter assays demonstrate that both beta-catenin/LEF-TCF- and TGFbeta-Smad-dependent signalling activities are upregulated, probably coregulating mesenchymal-specific gene expression during EMT. Stable expression of E-cadherin in mesenchymal FosER cells decreased beta-catenin activity and reduced cell proliferation. However, these cells still exhibited a defect in epithelial polarization and expressed E-cadherin/beta-catenin complexes in the entire plasma membrane. On the other hand, inhibition of TGFbeta-Smad signalling in mesenchymal FosER cells induced flat, cobblestone-like clusters of cells, which relocalized beta-catenin to the plasma membrane but still lacked detectable E-cadherin. Interestingly, inhibition of TGFbeta signalling in the E-cadherin-expressing mesenchymal FosER cells caused their reversion to a polarized epithelial phenotype, in which E-cadherin, beta-catenin, and ZO-1 were localized at their correct lateral plasma membrane domains. These results demonstrate that loss of E-cadherin can contribute to increased LEF/TCF-beta-catenin signalling, which in turn cooperates with autocrine TGFbeta signalling to maintain an undifferentiated mesenchymal phenotype.