RESUMO
Phosphoinositide-3-kinases (PI3K) are a family of lipid kinases mediating numerous cell processes such as proliferation, migration and differentiation. PI3K is an important target for cancer therapeutics due to the deregulation of this signaling pathway in a wide variety of human cancers. Herein, we describe the rapid identification of ETP-46992, within 2-aminocarbonyl imidazo [1,2-a] pyrazine series, with suitable pharmacokinetic (PK) properties that allows the establishment of mechanism of action and efficacy in vivo studies. ETP-46992 showed tumor growth inhibition in a GEMM mouse tumor model driven by a K-Ras(G12V) oncogenic mutation and in tumor xenograft models with PI3K pathway deregulated (BT474).
Assuntos
Imidazóis/química , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/química , Pirazinas/química , Serina-Treonina Quinases TOR/antagonistas & inibidores , Administração Oral , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Citocromos/metabolismo , Modelos Animais de Doenças , Meia-Vida , Humanos , Imidazóis/síntese química , Imidazóis/farmacocinética , Camundongos , Camundongos Endogâmicos BALB C , Microssomos Hepáticos/metabolismo , Neoplasias/tratamento farmacológico , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacocinética , Inibidores de Proteínas Quinases/uso terapêutico , Pirazinas/síntese química , Pirazinas/farmacocinética , Serina-Treonina Quinases TOR/metabolismo , Transplante HeterólogoRESUMO
Phosphoinositide-3-kinase (PI3K) is an important target for cancer therapeutics due to the deregulation of this signaling pathway in a wide variety of human cancers. Herein, we describe the optimization of imidazo [1,2-a] pyrazines, which allow us to identify compound 14 (ETP-46321), with potent biochemical and cellular activity and good pharmacokinetic properties (PK) after oral dosing. ETP-46321 PK/PD studies showed time dependent downregulation of AKT(Ser473) phosphorylation, which correlates with compound levels in tumor tissue and demonstrating to be efficacious in a GEMM mouse tumor model driven by a K-Ras(G12V) oncogenic mutation. Treatment with ETP-46321 resulted in significant tumor growth inhibition.
Assuntos
Imidazóis/farmacologia , Isoenzimas/antagonistas & inibidores , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/farmacologia , Pirazinas/farmacologia , Administração Oral , Disponibilidade Biológica , Humanos , Imidazóis/administração & dosagem , Imidazóis/farmacocinética , Tomografia por Emissão de Pósitrons , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacocinética , Pirazinas/administração & dosagem , Pirazinas/farmacocinética , Tomografia Computadorizada por Raios XRESUMO
The PI3K/AKT/mTOR and PIM kinase pathways contribute to the development of several hallmarks of cancer. Cotargeting of these pathways has exhibited promising synergistic therapeutic effects in liquid and solid tumor types. To identify molecules with combined activities, we cross-screened our collection of PI3K/(±mTOR) macrocycles (MCXs) and identified the MCX thieno[3,2-d]pyrimidine derivative 2 as a moderate dual PI3K/PIM-1 inhibitor. We report the medicinal chemistry exploration and biological characterization of a series of thieno[3,2-d]pyrimidine MCXs, which led to the discovery of IBL-302 (31), a potent, selective, and orally bioavailable triple PI3K/mTOR/PIM inhibitor. IBL-302, currently in late preclinical development (AUM302), has recently demonstrated efficacy in neuroblastoma and breast cancer xenografts. Additionally, during the course of our experiments, we observed that macrocyclization was essential to obtain the desired multitarget profile. As a matter of example, the open precursors 35-37 were inactive against PIM whereas MCX 28 displayed low nanomolar activity.
RESUMO
High-throughput assays are a common strategy for the identification of compounds able to modulate a certain cellular activity. Here, we show an automatized analysis platform for the quantification of nuclear foci as inhibitory effect of compounds on a target protein labeled by fluorescent antibodies. Our experience led us to a fast analysis platform that combines cell-based assays, high-content screening, and confocal microscopy, with an automatic and user-friendly statistical analysis of plate-based assays including positive and negative controls, able to identify inhibitory effect of compounds tested together with the Z-prime and Window of individual plate-based assays to assess the reliability of the results. The platform integrates a web-based tool implemented in Pipeline Pilot and R, and allows computing the inhibition values of different parameters obtained from the high-content screening and confocal microscopy analysis. This facilitates the exploration of the results using the different parameters, providing information at different levels as the number of foci observed, the sum of intensity of foci, area of foci, etc, the detection and filtering of outliers over the assay plate, and finally providing a set of statistics of the parameters studied together with a set of plots that we believe significantly helps to the interpretation of the assay results.
Assuntos
Imunofluorescência/métodos , Ensaios de Triagem em Larga Escala/métodos , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/metabolismo , Proteína 1 de Ligação a Repetições Teloméricas/metabolismo , Anticorpos/imunologia , Linhagem Celular Tumoral , Avaliação Pré-Clínica de Medicamentos/métodos , Corantes Fluorescentes/química , Humanos , Microscopia Confocal , Imagem Óptica , Reprodutibilidade dos Testes , Telômero/metabolismo , Telômero/ultraestruturaRESUMO
Telomeres are considered as universal anti-cancer targets, as telomere maintenance is essential to sustain indefinite cancer growth. Mutations in telomerase, the enzyme that maintains telomeres, are among the most frequently found in cancer. In addition, mutations in components of the telomere protective complex, or shelterin, are also found in familial and sporadic cancers. Most efforts to target telomeres have focused in telomerase inhibition; however, recent studies suggest that direct targeting of the shelterin complex could represent a more effective strategy. In particular, we recently showed that genetic deletion of the TRF1 essential shelterin protein impairs tumor growth in aggressive lung cancer and glioblastoma (GBM) mouse models by direct induction of telomere damage independently of telomere length. Here, we screen for TRF1 inhibitory drugs using a collection of FDA-approved drugs and drugs in clinical trials, which cover the majority of pathways included in the Reactome database. Among other targets, we find that inhibition of several kinases of the Ras pathway, including ERK and MEK, recapitulates the effects of Trf1 genetic deletion, including induction of telomeric DNA damage, telomere fragility, and inhibition of cancer stemness. We further show that both bRAF and ERK2 kinases phosphorylate TRF1 in vitro and that these modifications are essential for TRF1 location to telomeres in vivo. Finally, we use these new TRF1 regulatory pathways as the basis to discover novel drug combinations based on TRF1 inhibition, with the goal of effectively blocking potential resistance to individual drugs in patient-derived glioblastoma xenograft models.
Assuntos
Glioma/tratamento farmacológico , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteínas de Neoplasias , Inibidores de Proteínas Quinases/farmacologia , Telômero/metabolismo , Animais , Linhagem Celular Tumoral , Feminino , Deleção de Genes , Glioma/genética , Glioma/metabolismo , Glioma/patologia , Humanos , Sistema de Sinalização das MAP Quinases/genética , Camundongos , Camundongos Nus , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Telômero/genética , Telômero/patologia , Proteína 1 de Ligação a Repetições Teloméricas/genética , Proteína 1 de Ligação a Repetições Teloméricas/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
PIM kinase family (PIM-1, PIM-2 and PIM-3) is an appealing target for the discovery and development of selective inhibitors, useful in various disease conditions in which these proteins are highly expressed, such as cancer. The significant effort put, in the recent years, towards the development of small molecules exhibiting inhibitory activity against this protein family has ended up with several molecules entering clinical trials. As part of our ongoing exploration for potential drug candidates that exhibit affinity towards this protein family, we have generated a novel chemical series of triazolo[4,3-b]pyridazine based tricycles by applying a scaffold hopping strategy over our previously reported potent pan-PIM inhibitor ETP-47453 (compound 2). The structure-activity relationship studies presented herein demonstrate a rather selective PIM-1/PIM-3 biochemical profile for this novel series of tricycles, although pan-PIM and PIM-1 inhibitors have also been identified. Selected examples show significant inhibition of the phosphorylation of BAD protein in a cell-based assay. Moreover, optimized and highly selective compounds, such as 42, did not show significant hERG inhibition at 20⯵M concentration, and proved its antiproliferative activity and utility in combination with particular antitumoral agents in several tumor cell lines.
Assuntos
Antineoplásicos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-pim-1/antagonistas & inibidores , Piridazinas/farmacologia , Quinolinas/farmacologia , Triazóis/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Descoberta de Drogas , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Proteínas Proto-Oncogênicas c-pim-1/metabolismo , Piridazinas/síntese química , Piridazinas/química , Quinolinas/síntese química , Quinolinas/química , Relação Estrutura-Atividade , Triazóis/síntese química , Triazóis/químicaRESUMO
Nuclear factor of activated T cells (NFAT) plays a prominent role in gene transcription during the immune response. Growing evidence demonstrates the implication of inducible phosphorylation of the transactivation domain (TAD) of NFAT in transcriptional activation of genes. We have analyzed the regulation of NFATc2 activation by Cot/Tpl2 and protein kinase C zeta (PKCzeta) in T cells. Our results show that PKCzeta and Cot/Tpl2 cooperate in regulating the transactivation activity mediated by the amino-terminal domain of NFATc2. Neither Cot/Tpl2 kinase nor PKCzeta-mediated induction of the transactivation activity of NFATc2 was affected by cyclosporin-A treatment, supporting a calcineurin independent route in the signaling pathways mediating NFATc2 activation. Co-precipitation experiments showed physical interaction among Cot/Tpl2, PKCzeta and NFATc2. Analysis of the transactivation activity of deletions in the N-terminal region of NFATc2, suggested the involvement of amino acids 52-64 of NFATc2 in the induction of its transactivating function by PKCzeta. This kinase in vitro phosphorylates NFATc2 and deletion and mutational studies identified Ser53 and Ser56 (of the SPPS motif) as substrates for PKCzeta. Thus, our results suggest that PKCzeta phosphorylation of Ser53 and Ser56 in the N-terminal TAD from NFATc2 potentiates its transactivating function in human T cells.
Assuntos
Regulação Enzimológica da Expressão Gênica , MAP Quinase Quinase Quinases/metabolismo , Fatores de Transcrição NFATC/química , Fatores de Transcrição NFATC/metabolismo , Proteína Quinase C/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Genes Reporter , Humanos , Células Jurkat , Luciferases/metabolismo , Fatores de Transcrição NFATC/genética , Fosforilação , Proteína Quinase C/análise , Estrutura Terciária de Proteína , Transcrição Gênica , TransfecçãoRESUMO
Telomeres and the insulin/PI3K pathway are considered hallmarks of aging and cancer. Here, we describe a role for PI3K/AKT in the regulation of TRF1, an essential component of the shelterin complex. PI3K and AKT chemical inhibitors reduce TRF1 telomeric foci and lead to increased telomeric DNA damage and fragility. We identify the PI3Kα isoform as responsible for this TRF1 inhibition. TRF1 is phosphorylated at different residues by AKT and these modifications regulate TRF1 protein stability and TRF1 binding to telomeric DNA in vitro and are important for in vivo TRF1 telomere location and cell viability. Patient-derived breast cancer PDX mouse models that effectively respond to a PI3Kα specific inhibitor, BYL719, show decreased TRF1 levels and increased DNA damage. These findings functionally connect two of the major pathways for cancer and aging, telomeres and the PI3K pathway, and pinpoint PI3K and AKT as novel targets for chemical modulation of telomere protection.