RESUMO
Advancing cure rates for high-risk acute lymphoblastic leukemia (ALL) has been limited by the lack of agents that effectively kill leukemic cells, sparing normal hematopoietic tissue. Molecular glues direct the ubiquitin ligase cellular machinery to target neosubstrates for protein degradation. We developed a novel cereblon modulator, SJ6986, that exhibits potent and selective degradation of GSPT1 and GSPT2 and cytotoxic activity against childhood cancer cell lines. Here, we report in vitro and in vivo testing of the activity of this agent in a panel of ALL cell lines and xenografts. SJ6986 exhibited similar cytotoxicity to the previously described GSPT1 degrader CC-90009 in a panel of leukemia cell lines in vitro, resulting in apoptosis and perturbation of cell cycle progression. SJ6986 was more effective than CC-90009 in suppressing leukemic cell growth in vivo, partly attributable to favorable pharmacokinetic properties, and did not significantly impair differentiation of human CD34+ cells ex vivo. Genome-wide CRISPR/Cas9 screening of ALL cell lines treated with SJ6986 confirmed that components of the CRL4CRBN complex, associated adaptors, regulators, and effectors were integral in mediating the action of SJ6986. SJ6986 is a potent, selective, orally bioavailable GSPT1/2 degrader that shows broad antileukemic activity and has potential for clinical development.
Assuntos
Antineoplásicos , Piperidonas , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Criança , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Antineoplásicos/química , Piperidonas/uso terapêutico , Isoindóis/uso terapêuticoRESUMO
Targeting cereblon (CRBN) is currently one of the most frequently reported proteolysis-targeting chimera (PROTAC) approaches, owing to favorable drug-like properties of CRBN ligands, immunomodulatory imide drugs (IMiDs). However, IMiDs are known to be inherently unstable, readily undergoing hydrolysis in body fluids. Here we show that IMiDs and IMiD-based PROTACs rapidly hydrolyze in commonly utilized cell media, which significantly affects their cell efficacy. We designed novel CRBN binders, phenyl glutarimide (PG) analogues, and showed that they retained affinity for CRBN with high ligand efficiency (LE >0.48) and displayed improved chemical stability. Our efforts led to the discovery of PG PROTAC 4 c (SJ995973), a uniquely potent degrader of bromodomain and extra-terminal (BET) proteins that inhibited the viability of human acute myeloid leukemia MV4-11 cells at low picomolar concentrations (IC50 =3â pM; BRD4 DC50 =0.87â nM). These findings strongly support the utility of PG derivatives in the design of CRBN-directed PROTACs.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/química , Piperidonas/química , Ubiquitina-Proteína Ligases/química , Humanos , Hidrólise , ProteóliseRESUMO
The Pim proteins (1, 2 and 3) are serine/threonine kinases that have been found to be upregulated in many hematological malignancies and solid tumors. As a result of overlapping functions among the three isoforms, inhibition of all three Pim kinases has become an attractive strategy for cancer therapy. Herein we describe our efforts in identifying potent pan-PIM inhibitors that are derived from our previously reported pyridyl carboxamide scaffold as part of a medicinal chemistry strategy to address metabolic stability.
Assuntos
Amidas/farmacologia , Desenho de Fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-pim-1/antagonistas & inibidores , Amidas/química , Cristalografia por Raios X , Relação Estrutura-AtividadeRESUMO
Despite significant advances over recent years, the treatment of T cell acute lymphoblastic leukemia (T-ALL) remains challenging. We have recently shown that a subset of T-ALL cases exhibited constitutive activation of the lymphocyte-specific protein tyrosine kinase (LCK) and were consequently responsive to treatments with LCK inhibitors and degraders such as dasatinib and dasatinib-based PROTACs. Here we report the design, synthesis and in vitro/vivo evaluation of SJ45566, a potent and orally bioavailable LCK PROTAC.
Assuntos
Proteína Tirosina Quinase p56(lck) Linfócito-Específica , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/antagonistas & inibidores , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/metabolismo , Humanos , Administração Oral , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Animais , Camundongos , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacocinética , Inibidores de Proteínas Quinases/síntese química , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Antineoplásicos/síntese química , Antineoplásicos/farmacocinética , Disponibilidade Biológica , Linhagem Celular Tumoral , Relação Estrutura-AtividadeRESUMO
Molecular-glue degraders are small molecules that induce a specific interaction between an E3 ligase and a target protein, resulting in the target proteolysis. The discovery of molecular glue degraders currently relies mostly on screening approaches. Here, we describe screening of a library of cereblon (CRBN) ligands against a panel of patient-derived cancer cell lines, leading to the discovery of SJ7095, a potent degrader of CK1α, IKZF1 and IKZF3 proteins. Through a structure-informed exploration of structure activity relationship (SAR) around this small molecule we develop SJ3149, a selective and potent degrader of CK1α protein in vitro and in vivo. The structure of SJ3149 co-crystalized in complex with CK1α + CRBN + DDB1 provides a rationale for the improved degradation properties of this compound. In a panel of 115 cancer cell lines SJ3149 displays a broad antiproliferative activity profile, which shows statistically significant correlation with MDM2 inhibitor Nutlin-3a. These findings suggest potential utility of selective CK1α degraders for treatment of hematological cancers and solid tumors.
Assuntos
Antineoplásicos , Neoplasias , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/química , Linhagem Celular , Neoplasias/tratamento farmacológico , Proteólise , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Thalidomide and its analogues are frequently used in PROTAC design. However, they are known to be inherently unstable, undergoing hydrolysis even in commonly utilized cell culture media. We recently reported that phenyl glutarimide (PG)-based PROTACs displayed improved chemical stability and, consequently, improved protein degradation efficacy and cellular potency. Our optimization efforts, aiming to further improve the chemical stability and eliminate the racemization-prone chiral center in PG, led us to the development of phenyl dihydrouracil (PD)-based PROTACs. Here we describe the design and synthesis of LCK-directing PD-PROTACs and compare their physicochemical and pharmacological properties to those of the corresponding IMiD and PG analogues.
RESUMO
Aberrant activation of the JAK-STAT signaling pathway has been implicated in the pathogenesis of a range of hematological malignancies and autoimmune disorders. Here we describe the design, synthesis, and characterization of JAK2/3 PROTACs utilizing a phenyl glutarimide (PG) ligand as the cereblon (CRBN) recruiter. SJ10542 displayed high selectivity over GSPT1 and other members of the JAK family and potency in patient-derived ALL cells containing both JAK2 fusions and CRLF2 rearrangements.
RESUMO
T cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy, and there is an unmet need for targeted therapies, especially for patients with relapsed disease. We have recently identified pre-T cell receptor and lymphocyte-specific protein tyrosine kinase (LCK) signaling as a common therapeutic vulnerability in T-ALL. LCK inhibitor dasatinib showed efficacy against T-ALL in preclinical studies and in patients with T-ALL; however, this is transient in most cases. Leveraging the proteolysis targeting chimera (PROTAC) approach, we developed a series of LCK degraders using dasatinib as an LCK ligand and phenyl-glutarimide as a cereblon-directing moiety. Our lead compound SJ11646 exhibited marked efficiency in cereblon-mediated LCK degradation in T-ALL cells. Relative to dasatinib, SJ11646 showed up to three orders of magnitude higher cytotoxicity in LCK-activated T-ALL cell lines and primary leukemia samples in vitro, with drastically prolonged suppression of LCK signaling. In vivo pharmacokinetic and pharmacodynamic profiling indicated a 630% increase in the duration of LCK suppression by SJ11646 over dasatinib in patient-derived xenograft models of T-ALL, which translated into its extended leukemia-free survival over dasatinib in vivo. Last, SJ11646 retained a high binding affinity to 51 human kinases, particularly ABL1, KIT, and DDR1, all of which are known drug targets in other cancers. Together, our dasatinib-based phenyl-glutarimide PROTACs are promising therapeutic agents in T-ALL and valuable tools for developing degradation-based therapeutics for other cancers.
Assuntos
Leucemia-Linfoma Linfoblástico de Células T Precursoras , Linhagem Celular Tumoral , Dasatinibe/farmacologia , Dasatinibe/uso terapêutico , Humanos , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Proteólise , Linfócitos T/metabolismoRESUMO
A series of novel 3,5-disubstituted indole derivatives as potent and selective inhibitors of all three members of the Pim kinase family is described. High throughput screen identified a pan-Pim kinase inhibitor with a promiscuous scaffold. Guided by structure-based drug design, SAR of the series afforded a highly selective indole chemotype that was further developed into a potent set of compounds against Pim-1, 2, and 3 (Pim-1 and Pim-3: IC(50)≤2nM and Pim-2: IC(50)≤100nM).
Assuntos
Descoberta de Drogas , Indóis/química , Indóis/farmacologia , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases/efeitos dos fármacos , Concentração Inibidora 50 , Modelos Moleculares , Relação Estrutura-AtividadeRESUMO
The quality of lead compounds is a key factor for determining the success of chemical probe and drug discovery programs. Given that high-throughput screening (HTS) continues to be a dominant lead generation paradigm, access to high-quality screening libraries is crucial for such efforts in both industry and academia. Here, we discuss the strategy implemented a decade ago to build from scratch one of the largest compound collections in academia, containing â¼575 000 carefully annotated small molecules, and a recent multidisciplinary effort designed to further enhance the collection to meet our research demands for the next decade.
Assuntos
Descoberta de Drogas , Ensaios de Triagem em Larga Escala/tendências , Bibliotecas de Moléculas Pequenas/normas , Descoberta de Drogas/métodos , Descoberta de Drogas/organização & administração , Humanos , Comunicação Interdisciplinar , Sondas Moleculares , Pesquisa Farmacêutica/tendênciasRESUMO
Whereas the PROTAC approach to target protein degradation greatly benefits from rational design, the discovery of small-molecule degraders relies mostly on phenotypic screening and retrospective target identification efforts. Here, we describe the design, synthesis, and screening of a large diverse library of thalidomide analogues against a panel of patient-derived leukemia and medulloblastoma cell lines. These efforts led to the discovery of potent and novel GSPT1/2 degraders displaying selectivity over classical IMiD neosubstrates, such as IKZF1/3, and high oral bioavailability in mice. Taken together, this study offers compound 6 (SJ6986) as a valuable chemical probe for studying the role of GSPT1/2 in vitro and in vivo, and it supports the utility of a diverse library of CRBN binders in the pursuit of targeting undruggable oncoproteins.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/química , Fatores de Terminação de Peptídeos/metabolismo , Proteólise/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Ubiquitina-Proteína Ligases/química , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Administração Oral , Animais , Sítios de Ligação , Linhagem Celular Tumoral , Meia-Vida , Humanos , Fator de Transcrição Ikaros/metabolismo , Camundongos , Simulação de Dinâmica Molecular , Estudos Retrospectivos , Bibliotecas de Moléculas Pequenas/administração & dosagem , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/metabolismo , Relação Estrutura-Atividade , Talidomida/administração & dosagem , Talidomida/análogos & derivados , Talidomida/metabolismo , Talidomida/farmacologia , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Overexpression of PIM 1, 2, and 3 kinases is frequently observed in many malignancies. Previously, we discovered a potent and selective pan-PIM kinase inhibitor, compound 2, currently in phase I clinical trials. In this work, we were interested in replacing the amino group on the cyclohexane ring in compound 2 with a hydroxyl group. Structure-based drug design led to cellularly potent but metabolically unstable tetra-substituted cyclohexyl diols. Efforts on the reduction of Log D by introducing polar heterocycles improved metabolic stability. Incorporating fluorine to the tetra-substituted cyclohexyl diol moiety further reduced Log D, resulting in compound 14, a cellularly potent tetra-substituted cyclohexyl diol inhibitor with moderate metabolic stability and good permeability. We also describe the development of efficient and scalable synthetic routes toward synthetically challenging tetra-substituted cyclohexyl diol compounds. In particular, intermediate 36 was identified as a versatile intermediate, enabling a large-scale synthesis of highly substituted cyclohexane derivatives.
Assuntos
Cicloexanóis/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-pim-1/antagonistas & inibidores , Linhagem Celular Tumoral , Cicloexanóis/síntese química , Cicloexanóis/metabolismo , Humanos , Microssomos Hepáticos/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Ligação Proteica , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/metabolismo , Proteínas Proto-Oncogênicas c-pim-1/metabolismo , Relação Estrutura-AtividadeRESUMO
Direct pharmacological inhibition of RAS has remained elusive, and efforts to target CRAF have been challenging due to the complex nature of RAF signaling, downstream of activated RAS, and the poor overall kinase selectivity of putative RAF inhibitors. Herein, we describe 15 (LXH254, Aversa, R.; et al. Int. Patent WO2014151616A1, 2014), a selective B/C RAF inhibitor, which was developed by focusing on drug-like properties and selectivity. Our previous tool compound, 3 (RAF709; Nishiguchi, G. A.; et al. J. Med. Chem. 2017, 60, 4969), was potent, selective, efficacious, and well tolerated in preclinical models, but the high human intrinsic clearance precluded further development and prompted further investigation of close analogues. A structure-based approach led to a pyridine series with an alcohol side chain that could interact with the DFG loop and significantly improved cell potency. Further mitigation of human intrinsic clearance and time-dependent inhibition led to the discovery of 15. Due to its excellent properties, it was progressed through toxicology studies and is being tested in phase 1 clinical trials.
Assuntos
Antineoplásicos/química , Descoberta de Drogas/métodos , Mutação/genética , Inibidores de Proteínas Quinases/química , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/genética , Animais , Antineoplásicos/farmacologia , Desenho de Fármacos , Descoberta de Drogas/tendências , Humanos , Simulação de Acoplamento Molecular/métodos , Simulação de Acoplamento Molecular/tendências , Mutação/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto/métodosRESUMO
Resistance to the RAF inhibitor vemurafenib arises commonly in melanomas driven by the activated BRAF oncogene. Here, we report antitumor properties of RAF709, a novel ATP-competitive kinase inhibitor with high potency and selectivity against RAF kinases. RAF709 exhibited a mode of RAF inhibition distinct from RAF monomer inhibitors such as vemurafenib, showing equal activity against both RAF monomers and dimers. As a result, RAF709 inhibited MAPK signaling activity in tumor models harboring either BRAFV600 alterations or mutant N- and KRAS-driven signaling, with minimal paradoxical activation of wild-type RAF. In cell lines and murine xenograft models, RAF709 demonstrated selective antitumor activity in tumor cells harboring BRAF or RAS mutations compared with cells with wild-type BRAF and RAS genes. RAF709 demonstrated a direct pharmacokinetic/pharmacodynamic relationship in in vivo tumor models harboring KRAS mutation. Furthermore, RAF709 elicited regression of primary human tumor-derived xenograft models with BRAF, NRAS, or KRAS mutations with excellent tolerability. Our results support further development of inhibitors like RAF709, which represents a next-generation RAF inhibitor with unique biochemical and cellular properties that enables antitumor activities in RAS-mutant tumors.Significance: In an effort to develop RAF inhibitors with the appropriate pharmacological properties to treat RAS mutant tumors, RAF709, a compound with potency, selectivity, and in vivo properties, was developed that will allow preclinical therapeutic hypothesis testing, but also provide an excellent probe to further unravel the complexities of RAF kinase signaling. Cancer Res; 78(6); 1537-48. ©2018 AACR.
Assuntos
2,2'-Dipiridil/análogos & derivados , Antineoplásicos/farmacologia , Benzamidas/farmacologia , Proteínas Proto-Oncogênicas B-raf/genética , Quinases raf/antagonistas & inibidores , Proteínas ras/genética , 2,2'-Dipiridil/farmacologia , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Humanos , MAP Quinase Quinase Quinases/antagonistas & inibidores , Camundongos Nus , Mutação , Inibidores de Proteínas Quinases/farmacologia , Multimerização Proteica , Ensaios Antitumorais Modelo de Xenoenxerto , Quinases raf/metabolismoRESUMO
SHP2 is a cytoplasmic protein tyrosine phosphatase encoded by the PTPN11 gene and is involved in cell proliferation, differentiation, and survival. Recently, we reported an allosteric mechanism of inhibition that stabilizes the auto-inhibited conformation of SHP2. SHP099 (1) was identified and characterized as a moderately potent, orally bioavailable, allosteric small molecule inhibitor, which binds to a tunnel-like pocket formed by the confluence of three domains of SHP2. In this report, we describe further screening strategies that enabled the identification of a second, distinct small molecule allosteric site. SHP244 (2) was identified as a weak inhibitor of SHP2 with modest thermal stabilization of the enzyme. X-ray crystallography revealed that 2 binds and stabilizes the inactive, closed conformation of SHP2, at a distinct, previously unexplored binding site-a cleft formed at the interface of the N-terminal SH2 and PTP domains. Derivatization of 2 using structure-based design resulted in an increase in SHP2 thermal stabilization, biochemical inhibition, and subsequent MAPK pathway modulation. Downregulation of DUSP6 mRNA, a downstream MAPK pathway marker, was observed in KYSE-520 cancer cells. Remarkably, simultaneous occupation of both allosteric sites by 1 and 2 was possible, as characterized by cooperative biochemical inhibition experiments and X-ray crystallography. Combining an allosteric site 1 inhibitor with an allosteric site 2 inhibitor led to enhanced pharmacological pathway inhibition in cells. This work illustrates a rare example of dual allosteric targeted protein inhibition, demonstrates screening methodology and tactics to identify allosteric inhibitors, and enables further interrogation of SHP2 in cancer and related pathologies.
Assuntos
Regulação Alostérica , Sítio Alostérico , Piperidinas/farmacologia , Proteína Tirosina Fosfatase não Receptora Tipo 11/antagonistas & inibidores , Pirimidinas/farmacologia , Sítios de Ligação , Linhagem Celular Tumoral , Cristalografia por Raios X , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Neoplasias/tratamento farmacológico , Conformação Proteica , Estabilidade ProteicaRESUMO
RAS oncogenes have been implicated in >30% of human cancers, all representing high unmet medical need. The exquisite dependency on CRAF kinase in KRAS mutant tumors has been established in genetically engineered mouse models and human tumor cells. To date, many small molecule approaches are under investigation to target CRAF, yet kinase-selective and cellular potent inhibitors remain challenging to identify. Herein, we describe 14 (RAF709) [ Aversa , Biaryl amide compounds as kinase inhibitors and their preparation . WO 2014151616, 2014 ], a selective B/C RAF inhibitor, which was developed through a hypothesis-driven approach focusing on drug-like properties. A key challenge encountered in the medicinal chemistry campaign was maintaining a balance between good solubility and potent cellular activity (suppression of pMEK and proliferation) in KRAS mutant tumor cell lines. We investigated the small molecule crystal structure of lead molecule 7 and hypothesized that disruption of the crystal packing would improve solubility, which led to a change from N-methylpyridone to a tetrahydropyranyl oxy-pyridine derivative. 14 proved to be soluble, kinase selective, and efficacious in a KRAS mutant xenograft model.
Assuntos
2,2'-Dipiridil/análogos & derivados , Antineoplásicos/farmacologia , Benzamidas/farmacologia , Quinases raf/antagonistas & inibidores , Proteínas ras/genética , 2,2'-Dipiridil/química , 2,2'-Dipiridil/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Benzamidas/química , Cristalografia por Raios X , Cães , Desenho de Fármacos , Descoberta de Drogas , Estabilidade de Medicamentos , Humanos , Concentração Inibidora 50 , Camundongos , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Neoplasias/genética , Proteínas Proto-Oncogênicas B-raf/química , Proteínas Proto-Oncogênicas p21(ras)/genética , Ratos , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Pan proviral insertion site of Moloney murine leukemia (PIM) 1, 2, and 3 kinase inhibitors have recently begun to be tested in humans to assess whether pan PIM kinase inhibition may provide benefit to cancer patients. Herein, the synthesis, in vitro activity, in vivo activity in an acute myeloid leukemia xenograft model, and preclinical profile of the potent and selective pan PIM kinase inhibitor compound 8 (PIM447) are described. Starting from the reported aminopiperidyl pan PIM kinase inhibitor compound 3, a strategy to improve the microsomal stability was pursued resulting in the identification of potent aminocyclohexyl pan PIM inhibitors with high metabolic stability. From this aminocyclohexyl series, compound 8 entered the clinic in 2012 in multiple myeloma patients and is currently in several phase 1 trials of cancer patients with hematological malignancies.
Assuntos
Leucemia Mieloide Aguda/tratamento farmacológico , Ácidos Picolínicos/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-pim-1/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Amidas/síntese química , Amidas/química , Amidas/uso terapêutico , Animais , Linhagem Celular Tumoral , Halogenação , Humanos , Leucemia Mieloide Aguda/metabolismo , Camundongos , Modelos Moleculares , Ácidos Picolínicos/síntese química , Ácidos Picolínicos/química , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-pim-1/metabolismoRESUMO
PURPOSE: PIM kinases have been shown to act as oncogenes in mice, with each family member being able to drive progression of hematologic cancers. Consistent with this, we found that PIMs are highly expressed in human hematologic cancers and show that each isoform has a distinct expression pattern among disease subtypes. This suggests that inhibitors of all three PIMs would be effective in treating multiple hematologic malignancies. EXPERIMENTAL DESIGN: Pan-PIM inhibitors have proven difficult to develop because PIM2 has a low Km for ATP and, thus, requires a very potent inhibitor to effectively block the kinase activity at the ATP levels in cells. We developed a potent and specific pan-PIM inhibitor, LGB321, which is active on PIM2 in the cellular context. RESULTS: LGB321 is active on PIM2-dependent multiple myeloma cell lines, where it inhibits proliferation, mTOR-C1 signaling and phosphorylation of BAD. Broad cancer cell line profiling of LGB321 demonstrates limited activity in cell lines derived from solid tumors. In contrast, significant activity in cell lines derived from diverse hematological lineages was observed, including acute lymphoblastic leukemia (ALL), acute myelogenous leukemia (AML), multiple myeloma and non-Hodgkin lymphoma (NHL). Furthermore, we demonstrate LGB321 activity in the KG-1 AML xenograft model, in which modulation of pharmacodynamics markers is predictive of efficacy. Finally, we demonstrate that LGB321 synergizes with cytarabine in this model. CONCLUSIONS: We have developed a potent and selective pan-PIM inhibitor with single-agent antiproliferative activity and show that it synergizes with cytarabine in an AML xenograft model. Our results strongly support the development of Pan-PIM inhibitors to treat hematologic malignancies.
Assuntos
Neoplasias Hematológicas/terapia , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas c-pim-1/genética , Proteínas Proto-Oncogênicas/genética , Animais , Linhagem Celular Tumoral , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/patologia , Humanos , Camundongos , Fosforilação , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-pim-1/antagonistas & inibidores , Transdução de Sinais/genética , Serina-Treonina Quinases TOR/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Proviral insertion of Moloney virus (PIM) 1, 2, and 3 kinases are serine/threonine kinases that normally function in survival and proliferation of hematopoietic cells. As high expression of PIM1, 2, and 3 is frequently observed in many human malignancies, including multiple myeloma, non-Hodgkins lymphoma, and myeloid leukemias, there is interest in determining whether selective PIM inhibition can improve outcomes of these human cancers. Herein, we describe our efforts toward this goal. The structure guided optimization of a singleton high throughput screening hit in which the potency against all three PIM isoforms was increased >10,000-fold to yield compounds with pan PIM K is < 10 pM, nanomolar cellular potency, and in vivo activity in an acute myeloid leukemia Pim-dependent tumor model is described.
RESUMO
We (a) describe the completion of a total synthesis of 7,11-epi-thyrsiferol (4), (b) compare the antimitotic activities of thyrsiferol (2), Delta15,28-dehydrothyrsiferol (3), and 7,11-epi-thyrsiferol (4), (c) evaluate the synergistic behavior of the title compound and colchicine to inhibit cell proliferation, and (d) describe the results of conformational searches that provide additional insight concerning the SAR profile of the thyrsiferol family of natural products.