RESUMO
Sitravatinib (MGCD516), a spectrum-selective receptor tyrosine kinase inhibitor targeting TAM (TYRO3, AXL, MERTK) and split kinase family receptors, has demonstrated preclinical anti-tumor activity and modulation of tumor microenvironment. This first-in-human phase 1/1b study included sitravatinib dose exploration and anti-tumor activity evaluation in selected patients with advanced solid tumors. Primary objectives included assessment of safety, pharmacokinetics and clinical activity of sitravatinib. Secondary objectives included identifying doses for further investigation and exploring molecular markers for patient selection. In phase 1, 32 patients received 10-200 mg, while phase 1b dose expansion comprised 161 patients (150 mg n = 99, 120 mg n = 62). Maximum tolerated dose was determined as 150 mg daily. Dose-limiting toxicity was reported in 4/28 evaluable phase 1 patients (three at 200 mg, one at 80 mg). In phase 1b, 120 mg was defined as the recommended dose due to tolerability. Treatment-related adverse events (TRAEs) were experienced by 174/193 patients (90.2%); grade ≥ 3 TRAEs in 103 patients (53.4%). Most common TRAEs were diarrhea, fatigue, hypertension and nausea; TRAEs led to treatment discontinuation in 26 patients (13.5%) and death in one patient. Sitravatinib was steadily absorbed and declined from plasma with a terminal elimination half-life of 42.1-51.5 h following oral administration. Overall objective response rate was 11.8% in phase 1b, 13.2% in patients with non-small cell lung cancer (NSCLC) and 4.2% in patients with NSCLC with prior checkpoint inhibitor experience. Sitravatinib demonstrated manageable safety and modest clinical activity in solid tumors. NCT02219711 (first posted August 14, 2014).
Assuntos
Anilidas , Neoplasias , Piridinas , Anilidas/efeitos adversos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Piridinas/efeitos adversos , Microambiente TumoralRESUMO
Bortezomib therapy has proven successful for the treatment of relapsed and/or refractory multiple myeloma (MM); however, prolonged treatment is associated with toxicity and development of drug resistance. Here, we show that the novel proteasome inhibitor NPI-0052 induces apoptosis in MM cells resistant to conventional and Bortezomib therapies. NPI-0052 is distinct from Bortezomib in its chemical structure, effects on proteasome activities, mechanisms of action, and toxicity profile against normal cells. Moreover, NPI-0052 is orally bioactive. In animal tumor model studies, NPI-0052 is well tolerated and prolongs survival, with significantly reduced tumor recurrence. Combining NPI-0052 and Bortezomib induces synergistic anti-MM activity. Our study therefore provides the rationale for clinical protocols evaluating NPI-0052, alone and together with Bortezomib, to improve patient outcome in MM.
Assuntos
Ácidos Borônicos/farmacologia , Lactonas/farmacologia , Mieloma Múltiplo/tratamento farmacológico , Inibidores de Proteases/farmacologia , Pirazinas/farmacologia , Pirróis/farmacologia , Administração Oral , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Ácidos Borônicos/uso terapêutico , Bortezomib , Caspases/metabolismo , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sinergismo Farmacológico , Genes bcl-2 , Humanos , Lactonas/administração & dosagem , Lactonas/química , Linfócitos/efeitos dos fármacos , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , NF-kappa B/metabolismo , Plasmocitoma/tratamento farmacológico , Complexo de Endopeptidases do Proteassoma/farmacologia , Pirazinas/uso terapêutico , Pirróis/administração & dosagem , Pirróis/química , Células Tumorais CultivadasRESUMO
PURPOSE: Combining proteasome and histone deacetylase (HDAC) inhibition has been seen to provide synergistic anti-tumor activity, with complementary effects on a number of signaling pathways. The novel bi-cyclic structure of marizomib with its unique proteasome inhibition, toxicology and efficacy profiles, suggested utility in combining it with an HDAC inhibitor such as vorinostat. Thus, in this study in vitro studies assessed the potential utility of combining marizomib and vorinostat, followed by a clinical trial with the objectives of assessing the recommended phase 2 dose (RP2D), pharmacokinetics (PK), pharmacodynamics (PD), safety and preliminary anti-tumor activity of the combination in patients. EXPERIMENTAL DESIGN: Combinations of marizomib and vorinostat were assessed in vitro. Subsequently, in a Phase 1 clinical trial patients with melanoma, pancreatic carcinoma or Non-small Cell Lung Cancer (NSCLC) were given escalating doses of weekly marizomib in combination with vorinostat 300 mg daily for 16 days in 28 day cycles. In addition to standard safety studies, proteasome inhibition and pharmacokinetics were assayed. RESULTS: Marked synergy of marizomib and vorinostat was seen in tumor cell lines derived from patients with NSCLC, melanoma and pancreatic carcinoma. In the clinical trial, 22 patients were enrolled. Increased toxicity was not seen with the combination. Co-administration did not appear to affect the PK or PD of either drug in comparison to historical data. Although no responses were demonstrated using RECIST criteria, 61% of evaluable patients demonstrated stable disease with 39% having decreases in tumor measurements. CONCLUSIONS: Treatment of multiple tumor cell lines with marizomib and vorinostat resulted in a highly synergistic antitumor activity. The combination of full dose marizomib with vorinostat is tolerable in patients with safety findings consistent with either drug alone.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Melanoma/tratamento farmacológico , Neoplasias Pancreáticas/tratamento farmacológico , Adulto , Idoso , Antineoplásicos/administração & dosagem , Antineoplásicos/sangue , Antineoplásicos/farmacocinética , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Apoptose/efeitos dos fármacos , Carcinoma/metabolismo , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Combinação de Medicamentos , Feminino , Inibidores de Histona Desacetilases/administração & dosagem , Inibidores de Histona Desacetilases/sangue , Inibidores de Histona Desacetilases/farmacocinética , Humanos , Ácidos Hidroxâmicos/administração & dosagem , Ácidos Hidroxâmicos/sangue , Ácidos Hidroxâmicos/farmacocinética , Lactonas/administração & dosagem , Lactonas/sangue , Lactonas/farmacocinética , Neoplasias Pulmonares/metabolismo , Masculino , Melanoma/metabolismo , Pessoa de Meia-Idade , Neoplasias Pancreáticas/metabolismo , Inibidores de Proteassoma/administração & dosagem , Inibidores de Proteassoma/sangue , Inibidores de Proteassoma/farmacocinética , Pirróis/administração & dosagem , Pirróis/sangue , Pirróis/farmacocinética , VorinostatRESUMO
KPU-105 (4), a potent anti-microtubule agent that contains a benzophenone was derived from the diketopiperazine-type vascular disrupting agent (VDA) plinabulin 3, which displays colchicine-like tubulin depolymerization activity. To develop derivatives with more potent anti-microtubule and cytotoxic activities, we further modified the benzophenone moiety of 4. Accordingly, we obtained a 4-fluorobenzophenone derivative 16j that inhibited tumor cell growth in vitro with a subnanomolar IC(50) value against HT-29 cells (IC(50)=0.5 nM). Next, the effect of 16j on mitotic spindles was evaluated in HeLa cells. Treatment with 3nM of 16j partially disrupted the interphase microtubule network. By contrast, treatment with the same concentration of CA-4 barely affected the microtubule network, indicating that 16j exhibited more potent anti-mitotic effects than did CA-4.
Assuntos
Antineoplásicos/síntese química , Benzofenonas/química , Dicetopiperazinas/química , Microtúbulos/química , Moduladores de Tubulina/síntese química , Antineoplásicos/química , Antineoplásicos/toxicidade , Benzofenonas/síntese química , Proliferação de Células/efeitos dos fármacos , Colchicina/química , Cristalografia por Raios X , Dicetopiperazinas/síntese química , Dicetopiperazinas/toxicidade , Células HT29 , Células HeLa , Humanos , Microtúbulos/metabolismo , Conformação Molecular , Relação Estrutura-Atividade , Moduladores de Tubulina/química , Moduladores de Tubulina/toxicidadeRESUMO
The present study was undertaken to compare the cellular transport characteristics of [(3)H]NPI-0052 (1R,4R,5S)-4-(2-chloroethyl)-1-((S)-((S)-cyclohex-2-enyl)(hydroxy)methyl)-5-methyl-6-oxa-2-azabicyclo[3.2.0]heptane-3,7-dione (marizomib; salinosporamide A) and [(3)H]NPI-0047 (1R,4R, 5S)-1-((S)-((S)-cyclohex-2-enyl)(hydroxy)methyl)-4-ethyl-5-methyl-6-oxa-2-azabicyclo[3.2.0]heptane-3,7-dione in RPMI 8226 multiple myeloma and PC-3 prostate adenocarcinoma cells to determine whether these properties explain differences in the cytotoxic potencies of these chemical analogs. The results indicate that marizomib, which possesses a chemical-leaving group, is more cytotoxic to both cell lines and inhibits proteasome activity more completely at lower concentrations than NPI-0047, a nonleaving-group analog. Moreover, it was found that both compounds accumulate in these cells by simple diffusion and the same carrier-mediated transport system. Although the rate of uptake is similar, the cellular efflux, which does not seem to be mediated by a major ATP-binding cassette (ABC)-efflux transporter, is more rapid for NPI-0047 than for marizomib. Experiments revealed that the irreversible binding of marizomib to the proteasome is responsible for its slower efflux, longer duration of action, and greater cytotoxicity compared with NPI-0047. The discovery that major ABC transporters of the multidrug resistance-associated protein family do not seem to be involved in the accumulation or removal of these agents suggests they may not be affected by multidrug resistance mechanisms during prolonged administration.
Assuntos
Antineoplásicos/farmacologia , Lactonas/farmacologia , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Pirróis/farmacologia , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Lactamas/metabolismoRESUMO
Large-scale fermentation of the marine actinomycete Salinispora tropica for production of salinosporamide A (NPI-0052; 1) clinical trials materials provided crude extracts containing minor secondary metabolites, including salinosporamide B (2) and a new congener, 3. Spectroscopic characterization revealed that 3 is identical to antiprotealide, a molecular hybrid of 20S proteasome inhibitors 1 and omuralide (4) not previously described as a natural product. Analysis of crude extracts from shake flask cultures of three wild-type S. tropica strains confirmed the production of antiprotealide at 1.1, 0.8, and 3.0 mg/L. Thus, antiprotealide is a natural product metabolite of S. tropica.
Assuntos
Actinobacteria/química , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Lactamas/química , Lactamas/isolamento & purificação , Lactonas/química , Lactonas/isolamento & purificação , Pirróis/química , Pirróis/isolamento & purificação , Animais , Produtos Biológicos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Concentração Inibidora 50 , Lactamas/farmacologia , Lactonas/farmacologia , Biologia Marinha , Estrutura Molecular , Complexo de Endopeptidases do Proteassoma , Pirróis/farmacologia , CoelhosRESUMO
NPI-2358 (1) is a potent antimicrotubule agent that was developed from a natural diketopiperazine, phenylahistin, which is currently in Phase I clinical trials as an anticancer drug. To understand the precise recognition mechanism of tubulin by this agent, we focused on its potent derivative, KPU-244 (2), which has been modified with a photoreactive benzophenone structure, and biotin-tagged KPU-244 derivatives (3 and 4), which were designed and synthesized for tubulin photoaffinity labeling. Introduction of the biotin structure at the p'-position of the benzophenone ring in 2 exhibited reduced, but significant biological activities with tubulin binding, tubulin depolymerization and cytotoxicity in comparison to the parent KPU-244. Therefore, tubulin photoaffinity labeling studies of biotin-derivatives 3 and 4 were performed by using Western blotting analysis after photoirradiation with 365 nm UV light. The results indicated that tubulin was covalently labeled by these biotin-tagged photoprobes. The labeling of compound 4 was competitively inhibited by the addition of diketopiperazine 1 or colchicine, and weakly inhibited by the addition of vinblastine. The results suggest that photoaffinity probe 4 specifically recognizes tubulin at the same binding site as anticancer drug candidate 1, and this leads to the disruption of microtubules. Probe 4 serves well as a useful chemical probe for potent antimicrotubule diketopiperazines, much like phenylahistin, and it also competes for the colchicine-binding site.
Assuntos
Antineoplásicos/química , Biotina/química , Dicetopiperazinas/química , Moduladores de Tubulina/química , Tubulina (Proteína)/química , Antineoplásicos/farmacologia , Biotina/metabolismo , Linhagem Celular Tumoral , Colchicina/química , Colchicina/farmacologia , Dicetopiperazinas/farmacologia , Humanos , Concentração Inibidora 50 , Marcadores de Fotoafinidade/síntese química , Marcadores de Fotoafinidade/química , Tubulina (Proteína)/metabolismo , Tubulina (Proteína)/efeitos da radiação , Moduladores de Tubulina/farmacologiaRESUMO
PURPOSE: In the current study, we examine the effects of a novel proteasome inhibitor, NPI-0052 (salinosporamide A), on proteasome function and nuclear factor-kappaB activation and evaluate its ability to enhance treatment response in colon cancer xenografts when administered orally. EXPERIMENTAL DESIGN: The effects of treatment on nuclear factor-kappaB activation, cell cycle regulation, and apoptosis were determined. The pharmacodynamic effect of NPI-0052 on 20S proteasome function was assayed in vivo following oral and i.v. drug administration and compared with treatment with bortezomib. The effect of combined treatment with chemotherapy was determined in a colon cancer xenograft model. RESULTS: We found that NPI-0052 is a potent, well-tolerated proteasome inhibitor that has pharmacodynamic properties distinct from bortezomib in that it achieves significantly higher and more sustained levels of proteasome inhibition. When combined with chemotherapy, NPI-0052 increases apoptosis and shifts cells toward G2 cell cycle arrest. When added to chemotherapy in vivo [using combinations of 5-fluorouracil (5-FU), CPT-11, Avastin (bevacizumab), leucovorin, and oxaliplatin], NPI-0052 significantly improved the tumoricidal response and resulted in a 1.8-fold increased response to CPT-11, 5-FU, and leucovorin triple-drug combination (P=0.0002, t test), a 1.5-fold increased response to the oxaliplatin, 5-FU, and leucovorin triple-drug combination (P=0.013, t test), and a 2.3-fold greater response to the CPT-11, 5-FU, leucovorin, and Avastin regimen (P=0.00057). CONCLUSIONS: The high level of proteasome inhibition achieved by NPI-0052 is well tolerated and significantly improves the tumoricidal response to multidrug treatment in a colon cancer xenograft model. Further evaluation of this novel proteasome inhibitor in clinical trials is indicated.
Assuntos
Adenocarcinoma/tratamento farmacológico , Neoplasias do Colo/tratamento farmacológico , Lactonas/farmacologia , Lactonas/uso terapêutico , Pirróis/farmacologia , Pirróis/uso terapêutico , Adenocarcinoma/metabolismo , Animais , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apoptose/efeitos dos fármacos , Ácidos Borônicos/farmacologia , Bortezomib , Ciclo Celular/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Vias de Administração de Medicamentos , Sinergismo Farmacológico , Feminino , Humanos , Lactonas/administração & dosagem , Camundongos , Camundongos Nus , NF-kappa B/metabolismo , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Pirazinas/farmacologia , Pirróis/administração & dosagem , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Salinosporamide A (1, NPI-0052) is a potent proteasome inhibitor in development for treating cancer. In this study, a series of analogues was assayed for cytotoxicity, proteasome inhibition, and inhibition of NF-kappaB activation. Marked reductions in potency in cell-based assays accompanied replacement of the chloroethyl group with unhalogenated substituents. Halogen exchange and cyclohexene ring epoxidation were well tolerated, while some stereochemical modifications significantly attenuated activity. These findings provide insights into structure-activity relationships within this novel series.
Assuntos
Actinobacteria , Antineoplásicos/síntese química , Lactonas/síntese química , Inibidores de Proteassoma , Pirróis/síntese química , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular , Linhagem Celular Tumoral , Humanos , Lactonas/química , Lactonas/farmacologia , Biologia Marinha , NF-kappa B/antagonistas & inibidores , Pirróis/química , Pirróis/farmacologia , Coelhos , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
NB1011, a phosphoramidate derivative of (E)-5-(2-bromovinyl)-2'-deoxyuridine, is a novel small molecule anticancer agent. NB1011 is selectively active against tumor cells expressing high levels of thymidylate synthase (TS), a critical enzyme in DNA biosynthesis. NB1011 is different from the current TS-targeted drugs, which require inhibition of TS to be effective, because NB1011 cytotoxicity depends upon activation by TS. Here we report a dose-dependent, antitumor activity of NB1011 against established Tomudex-resistant breast cancer (MCF7TDX) xenografts in athymic mice. Against 5-fluorouracil-resistant colon carcinoma (H630R10) xenografts, NB1011 was as efficacious as irinotecan, a drug recently approved for the treatment of 5-fluorouracil-resistant colon cancer. To gain insight into the mechanisms NB1011 uses to suppress cellular growth, we analyzed the downstream molecular events in the high TS-expressing MCF7TDX and RKOTDX cell lines upon NB1011 treatment. NB1011 treatment increased the mRNA levels of p21, Bax, and GADD45. Furthermore, NB1011 induced p53, p21, and Bax proteins specifically in high TS-expressing tumor cells, whereas no induction was observed in low TS-expressing tumor cells (MCF7) or normal cells (WI38). Cell cycle analysis demonstrated that NB1011 treatment of MCF7TDX and RKOTDX cells resulted in an accumulation of cells in the G2-M phase of the cell cycle. Altogether, our data indicate that the induction of the p53 target genes p21, bax, and GADD45, with a concomitant deregulation of the cell cycle, may represent one of the mechanisms by which NB1011 exerts its growth-suppressive effects.
Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Neoplasias da Mama/patologia , Bromodesoxiuridina/farmacologia , Neoplasias do Colo/patologia , Proteína Oncogênica p21(ras)/biossíntese , Biossíntese de Proteínas , Proteínas Proto-Oncogênicas c-bcl-2 , Proteínas Proto-Oncogênicas/biossíntese , Timidilato Sintase/metabolismo , Proteína Supressora de Tumor p53/biossíntese , Animais , Anexina A5/metabolismo , Apoptose/efeitos dos fármacos , Neoplasias da Mama/enzimologia , Bromodesoxiuridina/análogos & derivados , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Neoplasias do Colo/enzimologia , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/biossíntese , Ciclinas/genética , Células Epiteliais/enzimologia , Feminino , Fibroblastos/enzimologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos , Camundongos Nus , Proteína Oncogênica p21(ras)/genética , Proteínas/genética , Proteínas Proto-Oncogênicas/genética , RNA Mensageiro/biossíntese , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/genética , Proteína X Associada a bcl-2 , Proteínas GADD45RESUMO
Plinabulin (11, NPI-2358) is a potent microtubule-targeting agent derived from the natural diketopiperazine "phenylahistin" (1) with a colchicine-like tubulin depolymerization activity. Compound 11 was recently developed as VDA and is now under phase II clinical trials as an anticancer drug. To develop more potent antimicrotubule and cytotoxic derivatives based on the didehydro-DKP skeleton, we performed further modification on the tert-butyl or phenyl groups of 11, and evaluated their cytotoxic and tubulin-binding activities. In the SAR study, we developed more potent derivatives 33 with 2,5-difluorophenyl and 50 with a benzophenone in place of the phenyl group. The anti-HuVEC activity of 33 and 50 exhibited a lowest effective concentration of 2 and 1 nM for microtubule depolymerization, respectively. The values of 33 and 50 were 5 and 10 times more potent than that of CA-4, respectively. These derivatives could be a valuable second-generation derivative with both vascular disrupting and cytotoxic activities.
Assuntos
Antineoplásicos/síntese química , Dicetopiperazinas/síntese química , Imidazóis/síntese química , Moduladores de Tubulina/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Cristalografia por Raios X , Dicetopiperazinas/química , Dicetopiperazinas/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Células HT29 , Células HeLa , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Imidazóis/química , Imidazóis/farmacologia , Conformação Molecular , Relação Quantitativa Estrutura-Atividade , Estereoisomerismo , Moduladores de Tubulina/química , Moduladores de Tubulina/farmacologiaRESUMO
PURPOSE: Plinabulin (NPI-2358) is a vascular disrupting agent that elicits tumor vascular endothelial architectural destabilization leading to selective collapse of established tumor vasculature. Preclinical data indicated plinabulin has favorable safety and antitumor activity profiles, leading to initiation of this clinical trial to determine the recommended phase 2 dose (RP2D) and assess the safety, pharmacokinetics, and biologic activity of plinabulin in patients with advanced malignancies. EXPERIMENTAL DESIGN: Patients received a weekly infusion of plinabulin for 3 of every 4 weeks. A dynamic accelerated dose titration method was used to escalate the dose from 2 mg/m² to the RP2D, followed by enrollment of an RP2D cohort. Safety, pharmacokinetic, and cardiovascular assessments were conducted, and Dynamic contrast-enhanced MRI (DCE-MRI) scans were performed to estimate changes in tumor blood flow. RESULTS: Thirty-eight patients were enrolled. A dose of 30 mg/m² was selected as the RP2D based on the adverse events of nausea, vomiting, fatigue, fever, tumor pain, and transient blood pressure elevations, with DCE-MRI indicating decreases in tumor blood flow (Ktrans) from 13.5 mg/m² (defining a biologically effective dose) with a 16% to 82% decrease in patients evaluated at 30 mg/m². Half-life was 6.06 ± 3.03 hours, clearance was 30.50 ± 22.88 L/h, and distributive volume was 211 ± 67.9 L. CONCLUSIONS: At the RP2D of 30 mg/m², plinabulin showed a favorable safety profile, while eliciting biological effects as evidenced by decreases in tumor blood flow, tumor pain, and other mechanistically relevant adverse events. On the basis of these results additional clinical trials were initiated with plinabulin in combination with standard chemotherapy agents.
Assuntos
Imidazóis/uso terapêutico , Linfoma/tratamento farmacológico , Neoplasias/tratamento farmacológico , Piperazinas/uso terapêutico , Adulto , Idoso , Inibidores da Angiogênese/administração & dosagem , Inibidores da Angiogênese/efeitos adversos , Inibidores da Angiogênese/farmacocinética , Inibidores da Angiogênese/uso terapêutico , Dicetopiperazinas , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Meia-Vida , Humanos , Imidazóis/administração & dosagem , Imidazóis/efeitos adversos , Imidazóis/farmacocinética , Infusões Intravenosas , Linfoma/metabolismo , Linfoma/patologia , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Neoplasias/irrigação sanguínea , Neoplasias/metabolismo , Neoplasias/patologia , Projetos Piloto , Piperazinas/administração & dosagem , Piperazinas/efeitos adversos , Piperazinas/farmacocinéticaRESUMO
Salinosporamide A ( 1 (NPI-0052)) is a potent, monochlorinated 20S proteasome inhibitor in clinical trials for the treatment of cancer. To elucidate the role of the chlorine leaving group (LG), we synthesized analogues with a range of LG potentials and determined their IC 50 values for inhibition of chymotrypsin-like (CT-L), trypsin-like (T-L), and caspase-like (C-L) activities of 20S proteasomes. Proteasome activity was also determined before and after attempted removal of the inhibitors by dialysis. Analogues bearing substituents with good LG potential exhibited the greatest potency and prolonged duration of proteasome inhibition, with no recovery after 24 h of dialysis. In contrast, activity was restored after =12 h in the case of non-LG analogues. Intermediate results were observed for fluorosalinosporamide, with poor LG potential. Kinetic studies indicate that 1 acts as a classical slow, tight inhibitor of the CT-L, T-L, and C-L activities and that inhibition occurs via a two-step mechanism involving reversible recognition followed by rate-limiting formation of a covalent enzyme-inhibitor complex.
Assuntos
Lactamas/síntese química , Lactamas/farmacologia , Lactonas/síntese química , Lactonas/farmacologia , Inibidores de Proteassoma , Pirróis/síntese química , Pirróis/farmacologia , Animais , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Hidrólise , Cinética , Lactamas/química , Lactonas/química , Modelos Moleculares , Estrutura Molecular , Complexo de Endopeptidases do Proteassoma/metabolismo , Subunidades Proteicas/antagonistas & inibidores , Subunidades Proteicas/metabolismo , Pirróis/química , Ratos , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Salinosporamide A (NPI-0052; 3), a highly potent inhibitor of the 20S proteasome, is currently in phase I clinical trials for the treatment of cancer. During the course of purifying multigram quantities of 3 from Salinispora tropica fermentation extracts, several new salinosporamides were isolated and characterized, most of which represent modifications to the chloroethyl substituent at C-2. Specifically, 3 was isolated along with the known compound salinosporamide B (4), the previously undescribed methyl congener salinosporamide D (7), and C-2 epimers of 3 and 7 (salinosporamides F (9) and G (10), respectively). Salinosporamide I (13), in which the methyl group at the ring junction is replaced with an ethyl group, and the C-5 deshydroxyl analogue salinosporamide J (14), were also identified. Replacement of synthetic sea salt with sodium bromide in the fermentation media produced bromosalinosporamide (12), 4, and its C-2 epimer (11, salinosporamide H). In addition to these eight new salinosporamides, several thioester derivatives were generated semisynthetically. IC50 values for cytotoxicity against human multiple myeloma cell line RPMI 8226 and inhibition of the chymotrypsin-like (CT-L) activity of purified rabbit 20S proteasomes were determined for all compounds. The results indicate that thioesters may directly inhibit the proteasome, albeit with reduced potency compared to their beta-lactone counterparts.
Assuntos
Actinobacteria/química , Lactonas , Inibidores de Proteassoma , Pirróis , Actinobacteria/crescimento & desenvolvimento , Bahamas , Cristalografia por Raios X , Concentração Inibidora 50 , Lactonas/química , Lactonas/isolamento & purificação , Lactonas/farmacologia , Biologia Marinha , Conformação Molecular , Estrutura Molecular , Pirróis/química , Pirróis/isolamento & purificação , Pirróis/farmacologiaRESUMO
Terpenoids constitute a large family of natural steroids that are widely distributed in plants and insects. We investigated the effects of a series of diterpenes structurally related to acanthoic acid in macrophage functions. We found that diterpenes with different substitutions at the C4 position in ring A are potent activators of liver X receptors (LXRalpha and LXRbeta) in both macrophage cell lines from human and mouse origin and primary murine macrophages. Activation of LXR by these diterpenes was evaluated in transient transfection assays and gene expression analysis of known LXR-target genes, including the cholesterol transporters ABCA1 and ABCG1, the sterol regulatory element-binding protein 1c, and the apoptosis inhibitor of macrophages (Spalpha). Moreover, active diterpenes greatly stimulated cholesterol efflux from macrophages. It is interesting that these diterpenes antagonize inflammatory gene expression mainly through LXR-dependent mechanisms, indicating that these compounds can activate both LXR activation and repression functions. Stimulation of macrophages with acanthoic acid diterpenes induced LXR-target gene expression and cholesterol efflux to similar levels observed with synthetic agonists 3-[3-[N-(2-chloro-3-trifluoromethylbenzyl)-(2,2-diphenylethyl)-amino]propyloxy]phenylacetic acid hydrochloride (GW3965) and N-(2,2,2-trifluoroethyl)-N-[4-[2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)-ethyl]phenyl]-benzenesulfonamide [T1317 (T0901317)]. These effects observed in gene expression were deficient in macrophages lacking both LXR isoforms (LXRalpha,beta(-/-)). These results show the ability of certain acanthoic acid diterpenes to activate efficiently both LXRs and suggest that these compounds can exert beneficial effects from a cardiovascular standpoint through LXR-dependent mechanisms.
Assuntos
Proteínas de Ligação a DNA/metabolismo , Diterpenos/farmacologia , Macrófagos/efeitos dos fármacos , Receptores Citoplasmáticos e Nucleares/metabolismo , Animais , Células Cultivadas , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/fisiologia , Diterpenos/química , Expressão Gênica , Humanos , Receptores X do Fígado , Macrófagos/metabolismo , Camundongos , Camundongos Knockout , Receptores Nucleares Órfãos , Receptores Citoplasmáticos e Nucleares/deficiência , Receptores Citoplasmáticos e Nucleares/efeitos dos fármacos , Receptores Citoplasmáticos e Nucleares/fisiologiaRESUMO
Salinosporamide A (also called NPI-0052), recently identified from the marine bacterium Salinispora tropica, is a potent inhibitor of 20S proteasome and exhibits therapeutic potential against a wide variety of tumors through a poorly understood mechanism. Here we demonstrate that salinosporamide A potentiated the apoptosis induced by tumor necrosis factor alpha (TNF), bortezomib, and thalidomide, and this correlated with down-regulation of gene products that mediate cell proliferation (cyclin D1, cyclooxygenase-2 [COX-2], and c-Myc), cell survival (Bcl-2, Bcl-xL, cFLIP, TRAF1, IAP1, IAP2, and survivin), invasion (matrix metallopro-teinase-9 [MMP-9] and ICAM-1), and angiogenesis (vascular endothelial growth factor [VEGF]). Salinosporamide A also suppressed TNF-induced tumor cell invasion and receptor activator of nuclear factor kappaB ligand (RANKL)-induced osteoclastogenesis. We also found that it suppressed both constitutive and inducible NF-kappaB activation. Compared with bortezomib, MG-132, N-acetyl-leucyl-leucyl-norleucinal (ALLN), and lactacystin, salinosporamide A was found to be the most potent suppressor of NF-kappaB activation. Further studies showed that salinosporamide A inhibited TNF-induced inhibitory subunit of NF-kappaB alpha (IkappaBalpha) degradation, nuclear translocation of p65, and NF-kappaB-dependent reporter gene expression but had no effect on IkappaBalpha kinase activation, IkappaBalpha phosphorylation, or IkappaBalpha ubiquitination. Thus, overall, our results indicate that salinosporamide A enhances apoptosis, suppresses osteoclastogenesis, and inhibits invasion through suppression of the NF-kappaB pathway.
Assuntos
Apoptose/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Lactonas/farmacologia , NF-kappa B/metabolismo , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Pirróis/farmacologia , Transporte Ativo do Núcleo Celular , Animais , Linhagem Celular , Ativação Enzimática , Regulação da Expressão Gênica , Genes Reporter/genética , Humanos , Proteínas I-kappa B/metabolismo , Camundongos , Camundongos Knockout , NF-kappa B/antagonistas & inibidores , NF-kappa B/deficiência , NF-kappa B/genética , Invasividade Neoplásica/patologia , Invasividade Neoplásica/prevenção & controle , Osteoclastos/citologia , Fosforilação , Inibidores de Proteases/farmacologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteassoma , Ligante RANK/farmacologia , Fatores de Tempo , Fatores de Necrose Tumoral/farmacologiaRESUMO
The diketopiperazine NPI-2358 is a synthetic analog of NPI-2350, a natural product isolated from Aspergillus sp., which depolymerizes microtubules in A549 human lung carcinoma cells. Although structurally different from the colchicine-binding site agents reported to date, NPI-2358 binds to the colchicine-binding site of tubulin. NPI-2358 has potent in-vitro anti-tumor activity against various human tumor cell lines and maintains activity against tumor cell lines with various multidrug-resistant (MDR) profiles. In addition, when evaluated in proliferating human umbilical vein endothelial cells (HUVECs), concentrations as low as 10 nmol/l NPI-2358 induced tubulin depolymerization within 30 min. Furthermore, NPI-2358 dose dependently increases HUVEC monolayer permeability--an in-vitro model of tumor vascular collapse. NPI-2358 was compared with three tubulin-depolymerizing agents with vascular-disrupting activity: colchicine, vincristine and combretastatin A-4 (CA4). Results showed that the activity of NPI-2358 in HUVECs was more potent than either colchicine or vincristine; the profile of CA4 approached that of NPI-2358. Altogether, our data show that NPI-2358 is a potent anti-tumor agent which is active in MDR tumor cell lines, and is able to rapidly induce tubulin depolymerization and monolayer permeability in HUVECs. These data warrant further evaluation of NPI-2358 as a vascular-disrupting agent in vivo. Currently, NPI-2358 is in preclinical development for the treatment of cancer.
Assuntos
Inibidores da Angiogênese/farmacologia , Antineoplásicos/farmacologia , Endotélio Vascular/efeitos dos fármacos , Imidazóis/farmacologia , Piperazinas/farmacologia , Tubulina (Proteína)/metabolismo , Permeabilidade da Membrana Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Colchicina/farmacologia , Dextranos/metabolismo , Dicetopiperazinas , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Fluoresceína-5-Isotiocianato/análogos & derivados , Fluoresceína-5-Isotiocianato/metabolismo , Células HL-60 , Células HT29 , Humanos , Concentração Inibidora 50 , Células Jurkat , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Neoplasias/irrigação sanguínea , Estilbenos/farmacologia , Fatores de Tempo , Vincristina/farmacologiaRESUMO
A strain of Streptomyces nodosus (NPS007994) isolated from a marine sediment collected in Scripps Canyon, La Jolla, California, was found to produce lajollamycin (1), a nitro-tetraene spiro-beta-lactone-gamma-lactam antibiotic. The structure was established by complete analysis of spectroscopic data and comparison with known antibiotics oxazolomycin (2), 16-methyloxazolomycin (3), and triedimycin B (4). Lajollamycin (1) showed antimicrobial activity against both drug-sensitive and -resistant Gram-positive bacteria and inhibited the growth of B16-F10 tumor cells in vitro.