RESUMEN
Duchenne muscular dystrophy (DMD) is a progressive disabling X-linked recessive disorder that causes gradual and irreversible loss of muscle, resulting in early death. The corticosteroids prednisone/prednisolone and deflazacort are used to treat DMD as the standard of care; however, only deflazacort is FDA approved for DMD. The novel atypical corticosteroid vamorolone is being investigated for treatment of DMD. We compared the pharmaceutical properties as well as the efficacy and safety of the three corticosteroids across multiple doses in the B10-mdx DMD mouse model. Pharmacokinetic studies in the mouse and evaluation of p-glycoprotein (P-gP) efflux in a cellular system demonstrated that vamorolone is not a strong P-gp substrate resulting in measurable central nervous system (CNS) exposure in the mouse. In contrast, deflazacort and prednisolone are strong P-gp substrates. All three corticosteroids showed efficacy, but also side effects at efficacious doses. After dosing mdx mice for two weeks, all three corticosteroids induced changes in gene expression in the liver and the muscle, but prednisolone and vamorolone induced more changes in the brain than did deflazacort. Both prednisolone and vamorolone induced depression-like behavior. All three corticosteroids reduced endogenous corticosterone levels, increased glucose levels, and reduced osteocalcin levels. Using micro-computed tomography, femur bone density was decreased, reaching significance with prednisolone. The results of these studies indicate that efficacious doses of vamorolone, are associated with similar side effects as seen with other corticosteroids. Further, because vamorolone is not a strong P-gp substrate, vamorolone distributes into the CNS increasing the potential CNS side-effects.
Asunto(s)
Distrofia Muscular de Duchenne , Prednisolona , Pregnadienodioles , Pregnenodionas , Animales , Ratones , Prednisolona/uso terapéutico , Microtomografía por Rayos X , Ratones Endogámicos mdx , Distrofia Muscular de Duchenne/tratamiento farmacológico , Distrofia Muscular de Duchenne/genética , Corticosterona/uso terapéutico , Preparaciones FarmacéuticasRESUMEN
Monomer tubulin polymerize into microtubules, which are highly dynamic and play a critical role in mitosis. Therefore, microtubule dynamics are an important target for anticancer drugs. The inhibition of tubulin polymerization or depolymerization was previously targeted and exhibited efficacy against solid tumors. The novel small molecule PTC596 directly binds tubulin, inhibits microtubule polymerization, downregulates MCL-1, and induces p53-independent apoptosis in acute myeloid leukemia cells. We herein investigated the efficacy of PTC-028, a structural analog of PTC596, for myelodysplastic syndrome (MDS). PTC-028 suppressed growth and induced apoptosis in MDS cell lines. The efficacy of PTC028 in primary MDS samples was confirmed using cell proliferation assays. PTC-028 synergized with hypomethylating agents, such as decitabine and azacitidine, to inhibit growth and induce apoptosis in MDS cells. Mechanistically, a treatment with PTC-028 induced G2/M arrest followed by apoptotic cell death. We also assessed the efficacy of PTC-028 in a xenograft mouse model of MDS using the MDS cell line, MDS-L, and the AkaBLI bioluminescence imaging system, which is composed of AkaLumine-HCl and Akaluc. PTC-028 prolonged the survival of mice in xenograft models. The present results suggest a chemotherapeutic strategy for MDS through the disruption of microtubule dynamics in combination with DNA hypomethylating agents.
Asunto(s)
Bencimidazoles/farmacología , Síndromes Mielodisplásicos/tratamiento farmacológico , Pirazinas/farmacología , Moduladores de Tubulina/farmacología , Animales , Antimetabolitos Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Apoptosis/genética , Bencimidazoles/uso terapéutico , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Decitabina/farmacología , Fase G2/efectos de los fármacos , Células HL-60 , Xenoinjertos , Humanos , Ratones , Síndromes Mielodisplásicos/genética , Paclitaxel/farmacología , Pirazinas/uso terapéutico , Análisis de Secuencia de ARN/métodos , Tubulina (Proteína)/efectos de los fármacos , Moduladores de Tubulina/uso terapéutico , Vincristina/farmacologíaRESUMEN
A structure-activity relationship investigation of various 6-(azaindol-2-yl)pyridine-3-sulfonamides using the HCV replicon cell culture assay led to the identification of a potent series of 7-azaindoles that target the hepatitis C virus NS4B. Compound 2ac, identified via further optimization of the series, has excellent potency against the HCV 1b replicon with an EC50 of 2nM and a selectivity index of >5000 with respect to cellular GAPDH RNA. Compound 2ac also has excellent oral plasma exposure levels in rats, dogs and monkeys and has a favorable liver to plasma distribution profile in rats.
Asunto(s)
Hepacivirus/enzimología , Piridinas/química , Piridinas/farmacología , Sulfonamidas/farmacología , Proteínas no Estructurales Virales/antagonistas & inhibidores , Animales , Antivirales/química , Antivirales/farmacología , Perros , Hepacivirus/efectos de los fármacos , Humanos , Macaca fascicularis , Ratas , Relación Estructura-ActividadRESUMEN
A novel series of 6-(indol-2-yl)pyridine-3-sulfonamides was prepared and evaluated for their ability to inhibit HCV RNA replication in the HCV replicon cell culture assay. Preliminary optimization of this series furnished compounds with low nanomolar potency against the HCV genotype 1b replicon. Among these, compound 8c has identified as a potent HCV replicon inhibitor (EC50=4 nM) with a selectivity index with respect to cellular GAPDH of more than 2500. Further, compound 8c had a good pharmacokinetic profile in rats with an IV half-life of 6h and oral bioavailability (F) of 62%. Selection of HCV replicon resistance identified an amino acid substitution in HCV NS4B that confers resistance to these compounds. These compounds hold promise as a new chemotype with anti-HCV activity mediated through an underexploited viral target.
Asunto(s)
Antivirales/farmacología , Descubrimiento de Drogas , Hepacivirus/efectos de los fármacos , Indoles/farmacología , Piridinas/farmacología , Sulfonamidas/farmacología , Proteínas no Estructurales Virales/antagonistas & inhibidores , Replicación Viral/efectos de los fármacos , Animales , Antivirales/administración & dosificación , Antivirales/química , Disponibilidad Biológica , Relación Dosis-Respuesta a Droga , Hepacivirus/genética , Humanos , Indoles/síntesis química , Indoles/química , Pruebas de Sensibilidad Microbiana , Microsomas Hepáticos/metabolismo , Estructura Molecular , Piridinas/síntesis química , Piridinas/química , Ratas , Relación Estructura-Actividad , Sulfonamidas/síntesis química , Sulfonamidas/química , Proteínas no Estructurales Virales/metabolismo , Replicación Viral/genéticaRESUMEN
Dihydroorotate dehydrogenase (DHODH) is the enzyme that catalyzes a rate-determining step during the de novo synthesis of uridine, an important source of cellular pyrimidine nucleotides. Ability to modulate the activity of this enzyme may be used to control diseases associated with rapid, out-of-control cell growth in oncology, immunology, and virology. Emvododstat (PTC299) is a tetrahydro-ß-carboline DHODH inhibitor discovered through the GEMS technology (Gene Expression Modulation by Small-Molecules). Described in this paper is the lead optimization campaign that culminated in the discovery of this highly potent DHODH inhibitor.
Asunto(s)
Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Dihidroorotato Deshidrogenasa , Inhibidores Enzimáticos/farmacología , CarbamatosRESUMEN
The novel small molecule PTC596 inhibits microtubule polymerization and its clinical development has been initiated for some solid cancers. We herein investigated the preclinical efficacy of PTC596 alone and in combination with proteasome inhibitors in the treatment of multiple myeloma (MM). PTC596 inhibited the proliferation of MM cell lines as well as primary MM samples in vitro, and this was confirmed with MM cell lines in vivo. PTC596 synergized with bortezomib or carfilzomib to inhibit the growth of MM cells in vitro. The combination treatment of PTC596 with bortezomib exerted synergistic effects in a xenograft model of human MM cell lines in immunodeficient mice and exhibited acceptable tolerability. Mechanistically, treatment with PTC596 induced cell cycle arrest at G2/M phase followed by apoptotic cell death, associated with the inhibition of microtubule polymerization. RNA sequence analysis also revealed that PTC596 and the combination with bortezomib affected the cell cycle and apoptosis in MM cells. Importantly, endoplasmic reticulum stress induced by bortezomib was enhanced by PTC596, providing an underlying mechanism of action of the combination therapy. Our results indicate that PTC596 alone and in combination with proteasome inhibition are potential novel therapeutic options to improve outcomes in patients with MM.
Asunto(s)
Bencimidazoles/farmacología , Proliferación Celular/efectos de los fármacos , Mieloma Múltiple/patología , Inhibidores de Proteasoma/farmacología , Pirazinas/farmacología , Tubulina (Proteína)/metabolismo , Animales , Bencimidazoles/administración & dosificación , Bencimidazoles/metabolismo , Bortezomib/administración & dosificación , Bortezomib/farmacología , Puntos de Control del Ciclo Celular/efectos de los fármacos , Quimioterapia Combinada , Estrés del Retículo Endoplásmico/efectos de los fármacos , Humanos , Ratones , Microtúbulos/efectos de los fármacos , Microtúbulos/metabolismo , Polimerizacion , Inhibidores de Proteasoma/administración & dosificación , Pirazinas/administración & dosificación , Pirazinas/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Dihydroorotate dehydrogenase (DHODH) catalyzes a rate-limiting step in de novo pyrimidine nucleotide synthesis. DHODH inhibition has recently been recognized as a potential new approach for treating acute myeloid leukemia (AML) by inducing differentiation. We investigated the efficacy of PTC299, a novel DHODH inhibitor, for myelodysplastic syndrome (MDS). PTC299 inhibited the proliferation of MDS cell lines, and this was rescued by exogenous uridine, which bypasses de novo pyrimidine synthesis. In contrast to AML cells, PTC299 was inefficient at inhibiting growth and inducing the differentiation of MDS cells, but synergized with hypomethylating agents, such as decitabine, to inhibit the growth of MDS cells. This synergistic effect was confirmed in primary MDS samples. As a single agent, PTC299 prolonged the survival of mice in xenograft models using MDS cell lines, and was more potent in combination with decitabine. Mechanistically, a treatment with PTC299 induced intra-S-phase arrest followed by apoptotic cell death. Of interest, PTC299 enhanced the incorporation of decitabine, an analog of cytidine, into DNA by inhibiting pyrimidine production, thereby enhancing the cytotoxic effects of decitabine. RNA-seq data revealed the marked downregulation of MYC target gene sets with PTC299 exposure. Transfection of MDS cell lines with MYC largely attenuated the growth inhibitory effects of PTC299, suggesting MYC as one of the major targets of PTC299. Our results indicate that the DHODH inhibitor PTC299 suppresses the growth of MDS cells and acts in a synergistic manner with decitabine. This combination therapy may be a new therapeutic option for the treatment of MDS.
Asunto(s)
Síndromes Mielodisplásicos , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Animales , ADN , Decitabina/farmacología , Dihidroorotato Deshidrogenasa , Ratones , Síndromes Mielodisplásicos/tratamiento farmacológico , Síndromes Mielodisplásicos/genéticaRESUMEN
PTC299 was identified as an inhibitor of VEGFA mRNA translation in a phenotypic screen and evaluated in the clinic for treatment of solid tumors. To guide precision cancer treatment, we performed extensive biological characterization of the activity of PTC299 and demonstrated that inhibition of VEGF production and cell proliferation by PTC299 is linked to a decrease in uridine nucleotides by targeting dihydroorotate dehydrogenase (DHODH), a rate-limiting enzyme for de novo pyrimidine nucleotide synthesis. Unlike previously reported DHODH inhibitors that were identified using in vitro enzyme assays, PTC299 is a more potent inhibitor of DHODH in isolated mitochondria suggesting that mitochondrial membrane lipid engagement in the DHODH conformation in situ is required for its optimal activity. PTC299 has broad and potent activity against hematologic cancer cells in preclinical models, reflecting a reduced pyrimidine nucleotide salvage pathway in leukemia cells. Archived serum samples from patients treated with PTC299 demonstrated increased levels of dihydroorotate, the substrate of DHODH, indicating target engagement in patients. PTC299 has advantages over previously reported DHODH inhibitors, including greater potency, good oral bioavailability, and lack of off-target kinase inhibition and myelosuppression, and thus may be useful for the targeted treatment of hematologic malignancies.
Asunto(s)
Neoplasias Hematológicas/tratamiento farmacológico , Imidazoles/administración & dosificación , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH/antagonistas & inhibidores , Tiazoles/administración & dosificación , Factor A de Crecimiento Endotelial Vascular/genética , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Dihidroorotato Deshidrogenasa , Neoplasias Hematológicas/sangre , Neoplasias Hematológicas/enzimología , Humanos , Imidazoles/farmacología , Células K562 , Ratones , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH/sangre , Tiazoles/farmacología , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
N1-Arylsulfonyltryptamines have been identified as 5-HT6 receptor ligands. In particular, N1-(6-chloroimidazo[2,1-b][1,3]thiazole-5-sulfonyl)tryptamine (11q) is a high affinity, potent full agonist (5-HT6 Ki = 2 nM, EC50 = 6.5 nM, Emax = 95.5%). Compound 11q is selective in a panel of over 40 receptors and ion channels, has good pharmacokinetic profile, has been shown to increase GABA levels in the rat frontal cortex, and is active in the schedule-induced polydipsia model for obsessive compulsive disorders.
Asunto(s)
Receptores de Serotonina/metabolismo , Agonistas de Receptores de Serotonina/síntesis química , Tiazoles/química , Triptaminas/síntesis química , Administración Oral , Animales , Disponibilidad Biológica , Células CHO , Cricetinae , Cricetulus , Perros , Lóbulo Frontal/metabolismo , Haplorrinos , Humanos , Técnicas In Vitro , Ratones , Microdiálisis , Microsomas Hepáticos/metabolismo , Ensayo de Unión Radioligante , Ratas , Agonistas de Receptores de Serotonina/farmacocinética , Agonistas de Receptores de Serotonina/farmacología , Solubilidad , Relación Estructura-Actividad , Tiazoles/farmacocinética , Tiazoles/farmacología , Triptaminas/química , Triptaminas/farmacocinética , Triptaminas/farmacología , Ácido gamma-Aminobutírico/metabolismoRESUMEN
Current anti-VEGF (Vascular Endothelial Growth Factor A) therapies to treat various cancers indiscriminately block VEGF function in the patient resulting in the global loss of VEGF signaling which has been linked to dose-limiting toxicities as well as treatment failures due to acquired resistance. Accumulating evidence suggests that this resistance is at least partially due to increased production of compensatory tumor angiogenic factors/cytokines. VEGF protein production is differentially controlled depending on whether cells are in the normal "homeostatic" state or in a stressed state, such as hypoxia, by post-transcriptional regulation imparted by elements in the 5' and 3' untranslated regions (UTR) of the VEGF mRNA. Using the Gene Expression Modulation by Small molecules (GEMS™) phenotypic assay system, we performed a high throughput screen to identify low molecular weight compounds that target the VEGF mRNA UTR-mediated regulation of stress-induced VEGF production in tumor cells. We identified a number of compounds that potently and selectively reduce endogenous VEGF production under hypoxia in HeLa cells. Medicinal chemistry efforts improved the potency and pharmaceutical properties of one series of compounds resulting in the discovery of PTC-510 which inhibits hypoxia-induced VEGF expression in HeLa cells at low nanomolar concentration. In mouse xenograft studies, oral administration of PTC-510 results in marked reduction of intratumor VEGF production and single agent control of tumor growth without any evident toxicity. Here, we show that selective suppression of stress-induced VEGF production within tumor cells effectively controls tumor growth. Therefore, this approach may minimize the liabilities of current global anti-VEGF therapies.
Asunto(s)
Inhibidores de la Angiogénesis/administración & dosificación , Antineoplásicos/administración & dosificación , Ensayos Analíticos de Alto Rendimiento/métodos , Neoplasias/tratamiento farmacológico , Regiones no Traducidas/efectos de los fármacos , Factor A de Crecimiento Endotelial Vascular/genética , Administración Oral , Inhibidores de la Angiogénesis/farmacología , Animales , Antineoplásicos/farmacología , Hipoxia de la Célula , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células HEK293 , Células HeLa , Células Hep G2 , Humanos , Ratones , Neoplasias/genética , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
5-Arylsulfonylamido-3-(pyrrolidin-2-ylmethyl)-1H-indoles have been identified as high-affinity 5-HT(6) receptor ligands. Within this class, several of the (R)-enantiomers were potent agonists having EC(50) values of 1 nM or less and functioning as full agonists while the (S)-enantiomers displayed moderate antagonist activity.
Asunto(s)
Indoles/síntesis química , Pirrolidinas/síntesis química , Receptores de Serotonina/efectos de los fármacos , Sulfonamidas/síntesis química , AMP Cíclico/agonistas , AMP Cíclico/antagonistas & inhibidores , AMP Cíclico/biosíntesis , Células HeLa , Humanos , Indoles/química , Indoles/farmacología , Pirrolidinas/química , Pirrolidinas/farmacología , Estereoisomerismo , Relación Estructura-Actividad , Sulfonamidas/química , Sulfonamidas/farmacologíaRESUMEN
A novel, potent, and orally bioavailable inhibitor of hepatitis C RNA replication targeting NS4B, compound 4t (PTC725), has been identified through chemical optimization of the 6-(indol-2-yl)pyridine-3-sulfonamide 2 to improve DMPK and safety properties. The focus of the SAR investigations has been to identify the optimal combination of substituents at the indole N-1, C-5, and C-6 positions and the sulfonamide group to limit the potential for in vivo oxidative metabolism and to achieve an acceptable pharmacokinetic profile. Compound 4t has excellent potency against the HCV 1b replicon, with an EC50 = 2 nM and a selectivity index of >5000 with respect to cellular GAPDH. Compound 4t has an overall favorable pharmacokinetic profile with oral bioavailability values of 62%, 78%, and 18% in rats, dogs, and monkeys, respectively, as well as favorable tissue distribution properties with a liver to plasma exposure ratio of 25 in rats.
Asunto(s)
Antivirales/farmacología , Hepacivirus/efectos de los fármacos , Sulfonamidas/farmacología , Administración Oral , Animales , Antivirales/administración & dosificación , Antivirales/farmacocinética , Área Bajo la Curva , Disponibilidad Biológica , Perros , Haplorrinos , Humanos , Ratas , Relación Estructura-Actividad , Sulfonamidas/administración & dosificación , Sulfonamidas/farmacocinéticaRESUMEN
A series of N(1)-arylsulfonyl-3-(1,2,3,6-tetrahydropyridin-4-yl)indole derivatives was designed and synthesized. These compounds were shown to have high affinity for the 5-HT(6) receptor. Two analogs, 4-[3-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indole-1-sulfonyl]-phenylamine 15g and 4-[3-(1,2,3,6-tetrahydropyridin-4-yl)-5-methoxy-1H-indole-1-sulfonyl]-phenylamine 15y, had 0.4 and 3.0 nM affinity, respectively, and antagonized the production of adenylate cyclase at sub-nanomolar concentrations.
Asunto(s)
Indoles/síntesis química , Receptores de Serotonina/metabolismo , Antagonistas de la Serotonina/síntesis química , Adenilil Ciclasas/metabolismo , Células HeLa , Humanos , Indoles/farmacología , Antagonistas de la Serotonina/farmacología , Relación Estructura-ActividadRESUMEN
Several series of conformationally constrained N1-arylsulfonyltryptamine derivatives were prepared and tested for 5-HT6 receptor binding affinity and ability to modulate cAMP production in a cyclase assay. The 3-piperidin-3-yl-, 3-(1-methylpyrrolidin-2-ylmethyl)-, and 3-pyrrolidin-3-yl-1H-indole arrays (8-13) appear to be able to adopt a conformation that allows high affinity 5-HT6 receptor binding, while the beta-carboline array 14 binds with a significantly weaker (10- to 100-fold) affinity. N1-Benzenesulfonyl-3-piperidin-3-yl-1H-indole 9a is a high affinity full agonist with EC50 = 24 nM. Several of the N1-arylsulfonyl-3-(1-methylpyrrolidin-2-ylmethyl)-1H-indole derivatives behave as very potent antagonists ((S)-11r, (S)-11t; IC50 = 0.8, 1.0 nM).