RESUMO
Down-regulation of Cisd2 in the liver has been implicated in the development of nonalcoholic fatty liver disease (NAFLD) and increasing the level of Cisd2 is therefore a potential therapeutic approach to this group of diseases. Herein, we describe the design, synthesis, and biological evaluation of a series of Cisd2 activators, all thiophene analogs, based on a hit obtained using two-stage screening and prepared via either the Gewald reaction or by intramolecular aldol-type condensation of an N,S-acetal. Metabolic stability studies of the resulting potent Cisd2 activators suggest that thiophenes 4q and 6 are suitable for in vivo studies. The results from studies on 4q-treated and 6-treated Cisd2hKO-het mice, which carry a heterozygous hepatocyte-specific Cisd2 knockout, confirm that (1) there is a correlation between Cisd2 levels and NAFLD and (2) these compounds have the ability to prevent, without detectable toxicity, the development and progression of NAFLD.
Assuntos
Hepatopatia Gordurosa não Alcoólica , Animais , Camundongos , Regulação para Baixo , Hepatócitos/metabolismo , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Tiofenos/farmacologia , Tiofenos/uso terapêuticoRESUMO
Gastrointestinal stromal tumors (GISTs) are prototypes of stem cell factor receptor (c-KIT)-driven cancer. Two receptor tyrosine kinases, c-KIT and fms-tyrosine kinase (FLT3), are frequently mutated in acute myeloid leukemia (AML) patients, and these mutations are associated with poor prognosis. In this study, we discovered a multitargeted tyrosine kinase inhibitor, compound 15a, with potent inhibition against single or double mutations of c-KIT developed in GISTs. Moreover, crystal structure analysis revealed the unique binding mode of 15a with c-KIT and may elucidate its high potency in inhibiting c-KIT kinase activity. Compound 15a inhibited cell proliferation and induced apoptosis by targeting c-KIT in c-KIT-mutant GIST cell lines. The antitumor effects of 15a were also demonstrated in GIST430 and GIST patient-derived xenograft models. Further studies demonstrated that 15a inhibited the proliferation of c-KIT- and FLT3-driven AML cells in vitro and in vivo. The results of this study suggest that 15a may be a potential anticancer drug for the treatment of GISTs and AML.
Assuntos
Antineoplásicos/farmacologia , Tumores do Estroma Gastrointestinal/tratamento farmacológico , Leucemia Mieloide Aguda/tratamento farmacológico , Mutação , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-kit/antagonistas & inibidores , Pirimidinas/farmacologia , Tirosina Quinase 3 Semelhante a fms/antagonistas & inibidores , Animais , Antineoplásicos/química , Apoptose , Proliferação de Células , Feminino , Neoplasias Gastrointestinais/tratamento farmacológico , Neoplasias Gastrointestinais/enzimologia , Neoplasias Gastrointestinais/genética , Neoplasias Gastrointestinais/patologia , Tumores do Estroma Gastrointestinal/enzimologia , Tumores do Estroma Gastrointestinal/genética , Tumores do Estroma Gastrointestinal/patologia , Humanos , Leucemia Mieloide Aguda/enzimologia , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Camundongos Endogâmicos NOD , Camundongos Nus , Camundongos SCID , Fosforilação , Inibidores de Proteínas Quinases/química , Proteínas Proto-Oncogênicas c-kit/genética , Pirimidinas/química , Ratos Sprague-Dawley , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto , Tirosina Quinase 3 Semelhante a fms/genéticaRESUMO
Epidermal growth factor receptor (EGFR)-targeted therapy in non-small cell lung cancer represents a breakthrough in the field of precision medicine. Previously, we have identified a lead compound, furanopyrimidine 2, which contains a (S)-2-phenylglycinol structure as a key fragment to inhibit EGFR. However, compound 2 showed high clearance and poor oral bioavailability in its pharmacokinetics studies. In this work, we optimized compound 2 by scaffold hopping and exploiting the potent inhibitory activity of various warhead groups to obtain a clinical candidate, 78 (DBPR112), which not only displayed a potent inhibitory activity against EGFRL858R/T790M double mutations but also exhibited tenfold potency better than the third-generation inhibitor, osimertinib, against EGFR and HER2 exon 20 insertion mutations. Overall, pharmacokinetic improvement through lead-to-candidate optimization yielded fourfold oral AUC better that afatinib along with F = 41.5%, an encouraging safety profile, and significant antitumor efficacy in in vivo xenograft models. DBPR112 is currently undergoing phase 1 clinical trial in Taiwan.
Assuntos
Antineoplásicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/metabolismo , Sítios de Ligação , Linhagem Celular Tumoral , Cristalografia por Raios X , Desenho de Fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/química , Receptores ErbB/genética , Receptores ErbB/metabolismo , Éxons , Humanos , Masculino , Camundongos Endogâmicos ICR , Camundongos Nus , Mutação , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/metabolismo , Pirimidinas/química , Ratos , Receptor ErbB-2 , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Hepatocellular carcinoma (HCC) ranks as the fourth leading cause of cancer-related deaths worldwide. Sorafenib was the only U.S. Food and Drug Administration (FDA) approved drug for treating advanced HCC until recently, so development of new target therapy is urgently needed. In this study, we established a zebrafish drug screening platform and compared the therapeutic effects of two multiple tyrosine kinase inhibitors, 419S1 and 420S1, with Sorafenib. All three compounds exhibited anti-angiogenesis abilities in immersed fli1:EGFP transgenic embryos and the half inhibition concentration (IC50) was determined. 419S1 exhibited lower hepatoxicity and embryonic toxicity than 420S1 and Sorafenib, and the half lethal concentration (LC50) was determined. The therapeutic index (LC50/IC50) for 419S1 was much higher than for Sorafenib and 420S1. The compounds were either injected retro-orbitally or by oral gavage to adult transgenic zebrafish with HCC. The compounds not only rescued the pathological feature, but also reversed the expression levels of cell-cycle-related genes and protein levels of a proliferation marker. Using a patient-derived-xenograft assay, we found that the effectiveness of 419S1 and 420S1 in preventing liver cancer proliferation is better than that of Sorafenib. With integrated efforts and the advantage of the zebrafish platform, we can find more effective and safe drugs for HCC treatment and screen for personalized medicine.
RESUMO
Drug resistance due to acquired mutations that constitutively activate c-KIT is a significant challenge in the treatment of patients with gastrointestinal stromal tumors (GISTs). Herein, we identified 1-(5-ethyl-isoxazol-3-yl)-3-(4-{2-[6-(4-ethylpiperazin-1-yl)pyrimidin-4-ylamino]-thiazol-5-yl}phenyl)urea (10a) as a potent inhibitor against unactivated and activated c-KIT. The binding of 10a induced rearrangements of the DFG motif, αC-helix, juxtamembrane domain, and the activation loop to switch the activated c-KIT back to its structurally inactive state. To the best of our knowledge, it is the first structural evidence demonstrating how a compound can inhibit the activated c-KIT by switching back to its inactive state through a sequence of conformational changes. Moreover, 10a can effectively inhibit various c-KIT mutants and the proliferation of several GIST cell lines. The distinct binding features and superior inhibitory potency of 10a, together with its excellent efficacy in the xenograft model, establish 10a as worthy of further clinical evaluation in the advanced GISTs.
Assuntos
Inibidores de Proteínas Quinases/química , Proteínas Proto-Oncogênicas c-kit/antagonistas & inibidores , Animais , Sítios de Ligação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Avaliação Pré-Clínica de Medicamentos , Tumores do Estroma Gastrointestinal/tratamento farmacológico , Tumores do Estroma Gastrointestinal/patologia , Humanos , Mesilato de Imatinib/química , Mesilato de Imatinib/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Simulação de Acoplamento Molecular , Inibidores de Proteínas Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-kit/genética , Proteínas Proto-Oncogênicas c-kit/metabolismo , Pirimidinas/química , Relação Estrutura-Atividade , Ureia/análogos & derivados , Ureia/metabolismo , Ureia/farmacologia , Ureia/uso terapêutico , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The first total synthesis of isopalhinineâ A, as well as unified syntheses of palhinineâ A and palhinineâ D, were successfully accomplished by means of a biomimetic strategy that proceeds through a bioinspired 5/6/6/9 tetracyclic intermediate, which mimics the amino ketone form of palhinineâ D. An early-stage direct SN 2 cyclization to construct the nine-membered azonane ring minimized the transannular strain that would otherwise be increased by the twisted nature of the isotwistane skeleton. Then, a diastereoselective Diels-Alder reaction of a masked ortho-benzoquinone using the nine-membered ring as a steric shielding group furnished a functionalized 6/6/9 tricyclic skeleton and established the desired stereochemistry at the C3, C7, C12, and C15 positions in one step. A thiol-mediated acyl radical cyclization gave the bioinspired intermediate bearing three differentiated oxygen-containing functional groups, from which all three total syntheses could be completed in either two or three additional steps.
Assuntos
Alcaloides/síntese química , Lycopodium/química , Triterpenos Pentacíclicos/síntese química , Alcaloides/química , Benzoquinonas/síntese química , Benzoquinonas/química , Biomimética , Ciclização , Reação de Cicloadição , Triterpenos Pentacíclicos/química , EstereoisomerismoRESUMO
Chronic myeloid leukemia (CML) is caused by chromosomal rearrangement resulting in the expression of Bcr-Abl fusion protein with deregulated Abl tyrosine kinase activity. Approved drugs - imatinib, dasatinib, nilotinib, and ponatinib - target the ATP-binding site of Abl kinase. Even though these drugs are initially effective, long-term usefulness is limited by the development of resistance. To overcome this problem, targeting the allosteric site of Abl kinase, which is remote from the ATP-binding site is found to be a useful strategy. In this study, structure-based and ligand-based virtual screening methods were applied to narrow down possible drugs (from DrugBank database) that could target the allosteric site of Abl kinase. Detailed investigations of the selected drugs in the allosteric site of Abl kinase, using molecular dynamics and steered molecular dynamics simulation shows that gefitinib, an EGFR inhibitor approved for the treatment of lung cancer, could bind effectively to the allosteric site of Bcr-Abl. More interestingly, gefitinib was found to enhance the ability of imatinib to bind at the ATP-binding site of Bcr-Abl kinase. Based on the in silico findings, gefitinib was tested in combination with imatinib in K562 CML cell line using MTT cell proliferation assay and found to have a synergistic antiproliferative activity. Further detailed mechanistic study could help to unravel the full potential of imatinib - gefitinib combination for the treatment of CML.
Assuntos
Antineoplásicos/farmacologia , Reposicionamento de Medicamentos , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Mesilato de Imatinib/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Quinazolinas/farmacologia , Sítio Alostérico , Sítios de Ligação , Domínio Catalítico , Proliferação de Células/efeitos dos fármacos , Dasatinibe/farmacologia , Bases de Dados de Compostos Químicos , Combinação de Medicamentos , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/química , Proteínas de Fusão bcr-abl/química , Proteínas de Fusão bcr-abl/metabolismo , Gefitinibe , Humanos , Células K562 , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Quinazolinas/química , TermodinâmicaRESUMO
The design and synthesis of a quinazoline-based, multi-kinase inhibitor for the treatment of acute myeloid leukemia (AML) and other malignancies is reported. Based on the previously reported furanopyrimidine 3, quinazoline core containing lead 4 was synthesized and found to impart dual FLT3/AURKA inhibition (IC50 = 127/5 nM), as well as improved physicochemical properties. A detailed structure-activity relationship study of the lead 4 allowed FLT3 and AURKA inhibition to be finely tuned, resulting in AURKA selective (5 and 7; 100-fold selective over FLT3), FLT3 selective (13; 30-fold selective over AURKA) and dual FLT3/AURKA selective (BPR1K871; IC50 = 19/22 nM) agents. BPR1K871 showed potent anti-proliferative activities in MOLM-13 and MV4-11 AML cells (EC50 ~ 5 nM). Moreover, kinase profiling and cell-line profiling revealed BPR1K871 to be a potential multi-kinase inhibitor. Functional studies using western blot and DNA content analysis in MV4-11 and HCT-116 cell lines revealed FLT3 and AURKA/B target modulation inside the cells. In vivo efficacy in AML xenograft models (MOLM-13 and MV4-11), as well as in solid tumor models (COLO205 and Mia-PaCa2), led to the selection of BPR1K871 as a preclinical development candidate for anti-cancer therapy. Further detailed studies could help to investigate the full potential of BPR1K871 as a multi-kinase inhibitor.
Assuntos
Antineoplásicos/síntese química , Aurora Quinase A/antagonistas & inibidores , Descoberta de Drogas , Leucemia Mieloide Aguda/tratamento farmacológico , Neoplasias/tratamento farmacológico , Inibidores de Proteínas Quinases/síntese química , Quinazolinas/síntese química , Tirosina Quinase 3 Semelhante a fms/antagonistas & inibidores , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Desenho de Fármacos , Humanos , Masculino , Modelos Moleculares , Inibidores de Proteínas Quinases/farmacologia , Ratos , Ratos Sprague-Dawley , Relação Estrutura-AtividadeRESUMO
Furanopyrimidine 1 (IC50 = 273 nM, LE = 0.36, LELP = 10.28) was recently identified by high-throughput screening (HTS) of an in-house library (125,000 compounds) as an Aurora kinase inhibitor. Structure-based hit optimization resulted in lead molecules with in vivo efficacy in a mouse tumour xenograft model, but no oral bioavailability. This is attributed to "molecular obesity", a common problem during hit to lead evolution during which degradation of important molecular properties such as molecular weight (MW) and lipophilicity occurs. This could be effectively tackled by the right choice of hit compounds for optimization. In this regard, ligand efficiency (LE) and ligand efficiency dependent lipophilicity (LELP) indices are more often used to choose fragment-like hits for optimization. To identify hits with appropriate LE, we used a MW cut-off <250, and pyrazole structure to filter HTS library. Next, structure-based virtual screening using software (Libdock and Glide) in the Aurora A crystal structure (PDB ID: 3E5A) was carried out, and the top scoring 18 compounds tested for Aurora A enzyme inhibition. This resulted in the identification of a novel tetrahydro-pyrazolo-isoquinoline hit 7 (IC50 = 852 nM, LE = 0.44, LELP = 8.36) with fragment-like properties suitable for further hit optimization. Moreover, hit 7 was found to be selective for Aurora A (Aurora B IC50 = 35,150 nM) and the possible reasons for selectivity investigated by docking two tautomeric forms (2H- and 3H-pyrazole) of 7 in Auroras A and B (PDB ID: 4AF3) crystal structures. This docking study shows that the major 3H-pyrazole tautomer of 7 binds in Aurora A stronger than in Aurora B.
Assuntos
Aurora Quinase A/antagonistas & inibidores , Avaliação Pré-Clínica de Medicamentos/métodos , Ensaios de Triagem em Larga Escala/métodos , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Relação Estrutura-Atividade , Aurora Quinase A/química , Humanos , Concentração Inibidora 50 , Ligantes , Simulação de Acoplamento Molecular , Peso Molecular , Pirazóis/químicaRESUMO
INTRODUCTION: EGFR has been implicated in various malignancies such as NSCLC, breast, head and neck, and pancreatic cancer. Numerous drugs have been developed in order to target the tyrosine domain of EGFR as an approach in cancer treatment. AREAS COVERED: This article focuses on the different generations of EGFR tyrosine kinase inhibitors (TKIs). This spans from the emergence of the first-generation EGFR-TKIs to overcoming drug resistance using second-generation EGFR-TKIs and to reducing adverse effect (AE) using mutant-selective third-generation EGFR-TKIs. EXPERT OPINION: Current TKI treatment is frequently accompanied by drug resistance and/or serious AEs. There has been the promise of advancements in second-generation EGFR-TKIs that could overcome drug resistance, acting as second- or third-line salvage treatment, but this promise has yet to be met. That being said, both issues are currently being addressed with mutant-selective EGFR-TKIs with the expectation of bringing more EGFR-targeted therapy into the next phase of cancer therapy in the future.
Assuntos
Receptores ErbB/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Animais , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Desenho de Fármacos , Resistencia a Medicamentos Antineoplásicos , Receptores ErbB/genética , Humanos , Terapia de Alvo Molecular , Mutação , Neoplasias/genética , Neoplasias/patologia , Inibidores de Proteínas Quinases/efeitos adversos , Inibidores de Proteínas Quinases/farmacologiaRESUMO
Here we report for the first time the use of fit quality (FQ), a ligand efficiency (LE) based measure for virtual screening (VS) of compound libraries. The LE based VS protocol was used to screen an in-house database of 125,000 compounds to identify aurora kinase A inhibitors. First, 20 known aurora kinase inhibitors were docked to aurora kinase A crystal structure (PDB ID: 2W1C); and the conformations of docked ligand were used to create a pharmacophore (PH) model. The PH model was used to screen the database compounds, and rank (PH rank) them based on the predicted IC50 values. Next, LE_Scale, a weight-dependant LE function, was derived from 294 known aurora kinase inhibitors. Using the fit quality (FQ = LE/LE_Scale) score derived from the LE_Scale function, the database compounds were reranked (PH_FQ rank) and the top 151 (0.12% of database) compounds were assessed for aurora kinase A inhibition biochemically. This VS protocol led to the identification of 7 novel hits, with compound 5 showing aurora kinase A IC50 = 1.29 µM. Furthermore, testing of 5 against a panel of 31 kinase reveals that it is selective toward aurora kinase A & B, with <50% inhibition for other kinases at 10 µM concentrations and is a suitable candidate for further development. Incorporation of FQ score in the VS protocol not only helped identify a novel aurora kinase inhibitor, 5, but also increased the hit rate of the VS protocol by improving the enrichment factor (EF) for FQ based screening (EF = 828), compared to PH based screening (EF = 237) alone. The LE based VS protocol disclosed here could be applied to other targets for hit identification in an efficient manner.
Assuntos
Avaliação Pré-Clínica de Medicamentos/métodos , Bibliotecas de Moléculas Pequenas/farmacologia , Interface Usuário-Computador , Aurora Quinase A/antagonistas & inibidores , Aurora Quinase A/química , Aurora Quinase A/metabolismo , Ensaios de Triagem em Larga Escala , Ligantes , Simulação de Acoplamento Molecular , Conformação Proteica , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Pirazóis/química , Pirazóis/metabolismo , Pirazóis/farmacologia , Pirimidinas/química , Pirimidinas/metabolismo , Pirimidinas/farmacologia , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/metabolismoRESUMO
Computer-guided drug design is a powerful tool for drug discovery. Herein we disclose the use of this approach for the discovery of dual FMS-like receptor tyrosine kinase-3 (FLT3)-Aurora A inhibitors against cancer. An Aurora hit compound was selected as a starting point, from which 288 virtual molecules were screened. Subsequently, some of these were synthesized and evaluated for their capacity to inhibit FLT3 and Aurora kinase A. To further enhance FLT3 inhibition, structure-activity relationship studies of the lead compound were conducted through a simplification strategy and bioisosteric replacement, followed by the use of computer-guided drug design to prioritize molecules bearing a variety of different terminal groups in terms of favorable binding energy. Selected compounds were then synthesized, and their bioactivity was evaluated. Of these, one novel inhibitor was found to exhibit excellent inhibition of FLT3 and Aurora kinase A and exert a dramatic antiproliferative effect on MOLM-13 and MV4-11 cells, with an IC50 value of 7 nM. Accordingly, it is considered a highly promising candidate for further development.
Assuntos
Antineoplásicos/farmacologia , Aurora Quinase A/antagonistas & inibidores , Desenho Assistido por Computador , Desenho de Fármacos , Inibidores de Proteínas Quinases/farmacologia , Tirosina Quinase 3 Semelhante a fms/antagonistas & inibidores , Antineoplásicos/síntese química , Antineoplásicos/química , Aurora Quinase A/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Relação Estrutura-Atividade , Tirosina Quinase 3 Semelhante a fms/metabolismoRESUMO
Ligand efficiency (LE) and lipophilic efficiency (LipE) are two important indicators of "drug-likeness", which are dependent on the molecule's activity and physicochemical properties. We recently reported a furano-pyrimidine Aurora kinase inhibitor 4 (LE = 0.25; LipE = 1.75), with potent activity in vitro; however, 4 was inactive in vivo. On the basis of insights obtained from the X-ray co-crystal structure of the lead 4, various solubilizing functional groups were introduced to optimize both the activity and physicochemical properties. Emphasis was placed on identifying potential leads with improved activity as well as better LE and LipE by exercising tight control over the molecular weight and lipophilicity of the molecules. Rational optimization has led to the identification of Aurora kinase inhibitor 27 (IBPR001; LE = 0.26; LipE = 4.78), with improved in vitro potency and physicochemical properties, resulting in an in vivo active (HCT-116 colon cancer xenograft mouse model) anticancer agent.
Assuntos
Antineoplásicos/farmacologia , Aurora Quinase A/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Aurora Quinase A/química , Aurora Quinase A/metabolismo , Peso Corporal/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Desenho de Fármacos , Furanos/química , Células HCT116 , Compostos Heterocíclicos com 2 Anéis/síntese química , Compostos Heterocíclicos com 2 Anéis/química , Compostos Heterocíclicos com 2 Anéis/farmacologia , Humanos , Ligantes , Lipídeos/química , Masculino , Camundongos , Camundongos Nus , Modelos Químicos , Modelos Moleculares , Estrutura Molecular , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia , Compostos de Fenilureia/síntese química , Compostos de Fenilureia/química , Compostos de Fenilureia/farmacologia , Ligação Proteica , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Estrutura Terciária de Proteína , Pirimidinas/síntese química , Pirimidinas/química , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Small synthetic compounds have been implicated in treatment of human cancers. We have synthesized a small compound, BPR1K0609S1 (hereafter, BP), which inhibits Aurora-A kinase. In the present study, we studied the mechanism of BP suppression of tumorigenesis induced by Aurora-A. Given our previous results that inactivation of p53 accelerates MMTV-Aurora-A-mediated tumorigenesis in vivo, we studied the roles of p53 pathway using the isogenic human colon carcinoma cell lines of HCT116, in which p53, Puma, Bax, p21 or Chk2 is deleted. When these isogenic cell lines are treated with BP for 48 h, accumulation of G2M phase and aneuploidy are commonly observed, and HCT116 p21(-) cells show increase in apoptosis. In xenograft assay, s.c. injection of BP efficiently inhibits tumorigenesis of HCT116 deficient for Chk2 or p21. Re-transplantation of BP-resistant tumors indicates that these resistant cells do not acquire advanced tumor growth. Significantly, 5-FU (5-fluorouracil) treatment further induces apoptosis of BP-resistant HCT116 deficient for Chk2 or Puma. These results demonstrate that p21 deficiency enhances BP-mediated suppression of tumor growth, and that BP and 5-FU can collaborate for tumor regression.
Assuntos
Inibidores Enzimáticos/farmacologia , Fluoruracila/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Aurora Quinase A , Aurora Quinases , Neoplasias Colorretais/tratamento farmacológico , Inibidores Enzimáticos/uso terapêutico , Feminino , Fluoruracila/uso terapêutico , Células HCT116 , Humanos , Camundongos , Camundongos Nus , Proteínas Serina-Treonina Quinases/antagonistas & inibidoresRESUMO
The overexpression of Aurora kinases in multiple tumors makes these kinases appealing targets for the development of anticancer therapies. This study identified two small molecules with a furanopyrimidine core, IBPR001 and IBPR002, that target Aurora kinases and induce a DFG conformation change at the ATP site of Aurora A. Our results demonstrate the high potency of the IBPR compounds in reducing tumorigenesis in a colorectal cancer xenograft model in athymic nude mice. Human hepatoma up-regulated protein (HURP) is a substrate of Aurora kinase A, which plays a crucial role in the stabilization of kinetochore fibers. This study used the IBPR compounds as well as MLN8237, a proven Aurora A inhibitor, as chemical probes to investigate the molecular role of HURP in mitotic spindle formation. These compounds effectively eliminated HURP phosphorylation, thereby revealing the coexistence and continuous cycling of HURP between unphosphorylated and phosphorylated forms that are associated, respectively, with microtubules emanating from centrosomes and kinetochores. Furthermore, these compounds demonstrate a spatial hierarchical preference for HURP in the attachment of microtubules extending from the mother to the daughter centrosome. The finding of inequality in the centrosomal microtubules revealed by these small molecules provides a versatile tool for the discovery of new cell-division molecules for the development of antitumor drugs.
Assuntos
Proteínas de Ciclo Celular/metabolismo , Centrossomo/ultraestrutura , Inibidores Enzimáticos/farmacologia , Cinetocoros/ultraestrutura , Microtúbulos/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Animais , Aurora Quinase A , Aurora Quinases , Carcinoma Hepatocelular/metabolismo , Ciclo Celular , Cristalografia por Raios X , Regulação Neoplásica da Expressão Gênica , Células HeLa , Humanos , Neoplasias Hepáticas/metabolismo , Masculino , Camundongos , Camundongos Nus , Mitose , Transplante de Neoplasias , Fosforilação , Estrutura Terciária de ProteínaRESUMO
The Asp-Phe-Gly (DFG) motif plays an important role in the regulation of kinase activity. Structure-based drug design was performed to design compounds able to interact with the DFG motif; epidermal growth factor receptor (EGFR) was selected as an example. Structural insights obtained from the EGFR/2a complex suggested that an extension from the meta-position on the phenyl group (ring-5) would improve interactions with the DFG motif. Indeed, introduction of an N,N-dimethylamino tail resulted in 4b, which showed almost 50-fold improvement in inhibition compared to 2a. Structural studies confirmed this N,N-dimethylamino tail moved toward the DFG motif to form a salt bridge with the side chain of Asp831. That the interactions with the DFG motif greatly contribute to the potency of 4b is strongly evidenced by synthesizing and testing compounds 2a, 3g, and 4f: when the charge interactions are absent, the inhibitory activity decreased significantly.
Assuntos
Receptores ErbB/antagonistas & inibidores , Oligopeptídeos/síntese química , Oligopeptídeos/farmacologia , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacologia , Cristalografia por Raios X , Desenho de Fármacos , Receptores ErbB/genética , Humanos , Modelos Moleculares , Mutação , Ligação Proteica , Conformação Proteica , Inibidores de Proteínas Quinases/química , Reação em Cadeia da Polimerase em Tempo Real , Relação Estrutura-AtividadeRESUMO
We describe the 3D-QSAR-assisted design of an Aurora kinaseâ A inhibitor with improved physicochemical properties, inâ vitro activity, and inâ vivo pharmacokinetic profiles over those of the initial lead. Three different 3D-QSAR models were built and validated by using a set of 66 pyrazole (Modelâ I) and furanopyrimidine (Modelâ II) compounds with IC(50) values toward Aurora kinaseâ A ranging from 33â nM to 10.5â µM. The best 3D-QSAR model, Modelâ III, constructed with 24 training set compounds from both series, showed robustness (r(2) (CV) =0.54 and 0.52 for CoMFA and CoMSIA, respectively) and superior predictive capacity for 42 test set compounds (R(2) (pred) =0.52 and 0.67, CoMFA and CoMSIA). Superimposition of CoMFA and CoMSIA Modelâ III over the crystal structure of Aurora kinaseâ A suggests the potential to improve the activity of the ligands by decreasing the steric clash with Val147 and Leu139 and by increasing hydrophobic contact with Leu139 and Gly216 residues in the solvent-exposed region of the enzyme. Based on these suggestions, the rational redesign of furanopyrimidine 24 (clog P=7.41; Auroraâ A IC(50) =43â nM; HCT-116 IC(50) =400â nM) led to the identification of quinazoline 67 (clog P=5.28; Auroraâ A IC(50) =25â nM; HCT-116 IC(50) =23â nM). Rat inâ vivo pharmacokinetic studies showed that 67 has better systemic exposure after i.v. administration than 24, and holds potential for further development.
Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Desenho de Fármacos , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Quinazolinas/química , Quinazolinas/farmacologia , Animais , Antineoplásicos/farmacocinética , Aurora Quinase A , Aurora Quinases , Humanos , Masculino , Modelos Moleculares , Neoplasias/tratamento farmacológico , Proteínas Serina-Treonina Quinases/metabolismo , Relação Quantitativa Estrutura-Atividade , Quinazolinas/farmacocinética , Ratos , Ratos Sprague-DawleyRESUMO
From a high-throughput screening (HTS) hit with inhibitory activity against virus-induced cytophathic in the low micromolar range, we have developed a potent anti-influenza lead through careful optimization without compromising the drug-like properties of the compound. An orally bioavailable compound was identified as a lead agent with nanomolar activity against influenza, representing a 140-fold improvement over the initial hit.
Assuntos
Antivirais/química , Antivirais/farmacologia , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Quinolinas/química , Quinolinas/farmacologia , Animais , Antivirais/farmacocinética , Linhagem Celular , Descoberta de Drogas , Humanos , Influenza Humana/tratamento farmacológico , Masculino , Infecções por Orthomyxoviridae/tratamento farmacológico , Quinolinas/farmacocinética , Ratos , Ratos Sprague-Dawley , Relação Estrutura-AtividadeRESUMO
BACKGROUND: Over-expression of Aurora kinases promotes the tumorigenesis of cells. The aim of this study was to determine the preclinical profile of a novel pan-Aurora kinase inhibitor, BPR1K653, as a candidate for anti-cancer therapy. Since expression of the drug efflux pump, MDR1, reduces the effectiveness of various chemotherapeutic compounds in human cancers, this study also aimed to determine whether the potency of BPR1K653 could be affected by the expression of MDR1 in cancer cells. PRINCIPAL FINDINGS: BPR1K653 specifically inhibited the activity of Aurora-A and Aurora-B kinase at low nano-molar concentrations in vitro. Anti-proliferative activity of BPR1K653 was evaluated in various human cancer cell lines. Results of the clonogenic assay showed that BPR1K653 was potent in targeting a variety of cancer cell lines regardless of the tissue origin, p53 status, or expression of MDR1. At the cellular level, BPR1K653 induced endo-replication and subsequent apoptosis in both MDR1-negative and MDR1-positive cancer cells. Importantly, it showed potent activity against the growth of xenograft tumors of the human cervical carcinoma KB and KB-derived MDR1-positive KB-VIN10 cells in nude mice. Finally, BPR1K653 also exhibited favorable pharmacokinetic properties in rats. CONCLUSIONS AND SIGNIFICANCE: BPR1K653 is a novel potent anti-cancer compound, and its potency is not affected by the expression of the multiple drug resistant protein, MDR1, in cancer cells. Therefore, BPR1K653 is a promising anti-cancer compound that has potential for the management of various malignancies, particularly for patients with MDR1-related drug resistance after prolonged chemotherapeutic treatments.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Compostos de Fenilureia/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Pirimidinas/farmacologia , Animais , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Aurora Quinase A , Aurora Quinase B , Aurora Quinases , Compostos Bicíclicos Heterocíclicos com Pontes/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ciclina B1/metabolismo , Regulação para Baixo/efeitos dos fármacos , Histonas/metabolismo , Humanos , Camundongos , Compostos de Fenilureia/química , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Pirimidinas/química , Ratos , Proteína Supressora de Tumor p53/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The human immunodeficiency virus type 1 (HIV-1)-encoded RNA-binding protein Tat is known to play an essential role in viral gene expression. In the search for novel compounds to inhibit Tat transactivity, one coumarin derivative, BPRHIV001, was identified, with a 50% effective concentration (EC(50)) against HIV-1 at 1.3 nM. BPRHIV001 is likely to exert its effects at the stage after initiation of RNAPII elongation since Tat protein expression and the assembly of the Tat/P-TEFb complex remained unchanged. Next, a reduction of the p300 protein level, known to modulate Tat function through acetylation, was observed upon BPRHIV001 treatment, while the p300 mRNA level was unaffected. A concordant reduction of phosphorylated Akt, which was shown to be closely related to p300 stability, was observed in the presence of BPRHIV001 and was accompanied by a decrease of phosphorylated PDPK1, a well-known Akt activator. Furthermore, the docking analysis revealed that the reduced PDPK1 phosphorylation likely resulted from the allosteric effect of interaction between BPRHIV001 and PDPK1. With strong synergistic effects with current reverse transcriptase inhibitors, BPRHIV001 has the potential to become a promising lead compound for the development of a novel therapeutic agent against HIV-1 infection.