RESUMEN
Caddisflies (Trichoptera) are among the most diverse groups of freshwater animals with more than 16 000 described species. They play a fundamental role in freshwater ecology and environmental engineering in streams, rivers and lakes. Because of this, they are frequently used as indicator organisms in biomonitoring programmes. Despite their importance, key questions concerning the evolutionary history of caddisflies, such as the timing and origin of larval case making, remain unanswered owing to the lack of a well-resolved phylogeny. Here, we estimated a phylogenetic tree using a combination of transcriptomes and targeted enrichment data for 207 species, representing 48 of 52 extant families and 174 genera. We calibrated and dated the tree with 33 carefully selected fossils. The first caddisflies originated approximately 295 million years ago in the Permian, and major suborders began to diversify in the Triassic. Furthermore, we show that portable case making evolved in three separate lineages, and shifts in diversification occurred in concert with key evolutionary innovations beyond case making.
Asunto(s)
Insectos , Filogenia , Insectos/clasificación , Insectos/genética , Insectos/fisiología , Agua Dulce , Transcriptoma , Biodiversidad , Fósiles , Evolución Biológica , AnimalesRESUMEN
Purpose: This in vitro study was designed to determine the effect of the pan-Janus kinase inhibitor, Tofacitinib, on basal and interleukin-6 (IL-6)-induced signal transducers and activators of transcription (STAT) phosphorylation and matrix metalloproteinase (MMP) gene expression and MMP production by C28/I2 human chondrocytes. Methods: C28/I2 chondrocytes were grown to a confluent high-density and treated either with recombinant human IL-6 (rhIL-6; 10-20ng/mL) or maintained in the basal state for up to 60 min. MMP gene expression was determined using RT-PCR and MMP production by semi-quantitative immunohistochemistry. The effect of IL-6 with or without Tofacitinib on activation of STAT proteins was determined from quantitative Western blots. Results: C28/I2 chondrocytes produced STAT1, STAT3 and STAT5AB which were phosphorylated (p) following treatment with rhIL-6 for 30 min. Tofacitinib (2.5nM-100nM) decreased rhIL-6-induced activation of STAT1, STAT3, and STAT5AB as well as decreasing the expression of MMP3 and MMP13 but not MMP9, MMP1 or MMP2. In addition, Tofacitinib (50nM) reduced the number of rhIL-6-induced MMP3-, and MMP13- antibody-positive C28/I2 chondrocytes. However, Tofacitinib did decrease the number of MMP9-antibody-positive C28/I2 chondrocytes. Conclusion: Taken together, these data showed that Tofacitinib, a pan-JAK small molecule inhibitor employed for the medical therapy of rheumatoid arthritis was a potent inhibitor of rhIL-6-induced STAT phosphorylation that appeared to be coupled to the inhibition of MMP-3, -9 and -13 production by C28/I2 chondrocytes.
RESUMEN
Androgen ablation is the standard of care prescribed to patients with advanced or metastatic prostate cancer (PCa) to slow down disease progression. Unfortunately, a majority of PCa patients under androgen ablation progress to castration-resistant prostate cancer (CRPC). Several mechanisms including alternative intra-prostatic androgen production and androgen-independent androgen receptor (AR) activation have been proposed for CRPC progression. Aldo-keto reductase family 1 member C3 (AKR1C3), a multi-functional steroid metabolizing enzyme, is specifically expressed in the cytoplasm of PCa cells; and positive immunoreactivity of the type A γ-aminobutyric acid receptor (GABAAR), an ionotropic receptor and ligand-gated ion channel, is detected on the membrane of PCa cells. We studied a total of 72 radical prostatectomy cases by immunohistochemistry, and identified that 21 cases exhibited positive immunoreactivities for both AKR1C3 and GABAAR. In the dual positive cancer cases, AKR1C3 and GABAAR subunit α1 were either expressed in the same cells or in neighboring cells. Among several possible substrates, AKR1C3 reduces 5α-dihydrotesterone (DHT) to form 5α-androstane-3α, 17ß-diol (3α-diol). 3α-diol is a neurosteroid that acts as a positive allosteric modulator of the GABAAR in the central nervous system (CNS). We examined the hypothesis that 3α-diol-regulated pathological effects in the prostate are GABAAR-dependent, but are independent of the AR. In GABAAR-positive, AR-negative human PCa PC-3 cells, 3α-diol significantly stimulated cell growth in culture and the in ovo chorioallantoic membrane (CAM) xenograft model. 3α-diol also up-regulated expression of the epidermal growth factor (EGF) family of growth factors and activation of EGF receptor (EGFR) and Src as measured by quantitative polymerase chain reaction and immunoblotting, respectively. Inclusion of GABAAR antagonists reversed 3α-diol-stimulated tumor cell growth, expression of EGF family members, and activation of EGFR and Src to the level observed in untreated cells. Results from the present study suggest that 3α-diol may act as an alternative intra-prostatic neurosteroid that activates AR-independent PCa progression. The involvement of AKR1C3-mediated steroid metabolisms in modulating GABAAR activation and promoting PCa progression requires continued studies.
Asunto(s)
Miembro C3 de la Familia 1 de las Aldo-Ceto Reductasas/metabolismo , Anabolizantes/farmacología , Androstano-3,17-diol/farmacología , Neoplasias de la Próstata/patología , Receptores de GABA-A/metabolismo , Miembro C3 de la Familia 1 de las Aldo-Ceto Reductasas/genética , Proliferación Celular , Progresión de la Enfermedad , Receptores ErbB/genética , Receptores ErbB/metabolismo , Humanos , Masculino , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , Receptores de GABA-A/genética , Transducción de Señal , Células Tumorales CultivadasRESUMEN
BACKGROUND: Cancer-specific survival has changed remarkably little over the past half century, mainly because metastases that are occult at diagnosis and generally resistant to chemotherapy subsequently develop months, years or even decades following definitive therapy. Targeting the dormant micrometastases responsible for these delayed or occult metastases would represent a major new tool in cancer patient management. Our hypothesis is that these metastases develop from micrometastatic cells that are suppressed by normal extracellular matrix (ECM). METHODS: A new screening method was developed that compared the effect of drugs on the proliferation of cells grown on a normal ECM gel (small intestine submucosa, SISgel) to cells grown on plastic cell culture plates. The desired endpoint was that cells on SISgel were more sensitive than the same cells grown as monolayers. Known cancer chemotherapeutic agents show the opposite pattern. RESULTS: Screening 13,000 compounds identified two leads with low toxicity in mice and EC50 values in the range of 3-30 µM, depending on the cell line, and another two leads that were too toxic to mice to be useful. In a novel flank xenograft method of suppressed/dormant cells co-injected with SISgel into the flank, the lead compounds significantly eliminated the suppressed cells, whereas conventional chemotherapeutics were ineffective. Using a 4T1 triple negative breast cancer model, modified for physiological metastatic progression, as predicted, both lead compounds reduced the number of large micrometastases/macrometastases in the lung. One of the compounds also targeted cancer stem cells (CSC) isolated from the parental line. The CSC also retained their stemness on SISgel. Mechanistic studies showed a mild, late apoptotic response and depending on the compound, a mild arrest either at S or G2/M in the cell cycle. CONCLUSIONS: In summary we describe a novel, first in class set of compounds that target micrometastatic cells and prevent their reactivation to form recurrent tumors/macrometastases.
Asunto(s)
Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Micrometástasis de Neoplasia/tratamiento farmacológico , Animales , Antineoplásicos/uso terapéutico , Neoplasias de la Mama/patología , Línea Celular Tumoral , Femenino , Concentración 50 Inhibidora , Dosis Máxima Tolerada , Ratones Endogámicos BALB C , Ratones Desnudos , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Therapy for treatment-resistant breast cancer provides limited options and the response rates are low. Therefore, the development of therapies with alternative chemotherapeutic strategies is necessary. AG311 (5-[(4-methylphenyl)thio]-9H-pyrimido[4,5-b]indole-2,4-diamine), a small molecule, is being investigated in preclinical and mechanistic studies for treatment of resistant breast cancer through necrosis, an alternative cell death mechanism. In vitro, AG311 induces rapid necrosis in numerous cancer cell lines as evidenced by loss of membrane integrity, ATP depletion, HMGB1 (high-mobility group protein B1) translocation, nuclear swelling, and stable membrane blebbing in breast cancer cells. Within minutes, exposure to AG311 also results in mitochondrial depolarization, superoxide production, and increased intracellular calcium levels. Additionally, upregulation of mitochondrial oxidative phosphorylation results in sensitization to AG311. This AG311-induced cell death can be partially prevented by treatment with the mitochondrial calcium uniporter inhibitor, Ru360 [(µ)[(HCO2)(NH3)4Ru]2OCl3], or an antioxidant, lipoic acid. Additionally, AG311 does not increase apoptotic markers such as cleavage of poly (ADP-ribose) polymerase (PARP) or caspase-3 and -7 activity. Importantly, in vivo studies in two orthotopic breast cancer mouse models (xenograft and allograft) demonstrate that AG311 retards tumor growth and reduces lung metastases better than clinically used agents and has no gross or histopathological toxicity. Together, these data suggest that AG311 is a first-in-class antitumor and antimetastatic agent inducing necrosis in breast cancer tumors, likely through the mitochondria.
Asunto(s)
Antineoplásicos/farmacología , Indoles/farmacología , Mitocondrias/efectos de los fármacos , Necrosis/inducido químicamente , Pirimidinas/farmacología , Neoplasias de la Mama Triple Negativas/patología , Animales , Antineoplásicos/toxicidad , Apoptosis/efectos de los fármacos , Calcio/metabolismo , Línea Celular Tumoral , Permeabilidad de la Membrana Celular/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Femenino , Homeostasis/efectos de los fármacos , Humanos , Indoles/toxicidad , Masculino , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Ratones , Mitocondrias/metabolismo , Metástasis de la Neoplasia , Pirimidinas/toxicidad , Ratas , Superóxidos/metabolismo , Factores de Tiempo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Antiangiogenic agents (AA) are cytostatic, and their utility in cancer chemotherapy lies in their combination with cytotoxic chemotherapeutic agents. Clinical combinations of vascular endothelial growth factor receptor-2 (VEGFR2) inhibitors with antitubulin agents have been particularly successful. We have discovered a novel, potentially important analogue, that combines potent VEGFR2 inhibitory activity (comparable to that of sunitinib) with potent antitubulin activity (comparable to that of combretastatin A-4 (CA)) in a single molecule, with GI50 values of 10(-7) M across the entire NCI 60 tumor cell panel. It potently inhibited tubulin assembly and circumvented the most clinically relevant tumor resistance mechanisms (P-glycoprotein and ß-III tubulin expression) to antimicrotubule agents. The compound is freely water-soluble as its HCl salt and afforded excellent antitumor activity in vivo, superior to docetaxel, sunitinib, or Temozolomide, without any toxicity.
RESUMEN
The design, synthesis and biological evaluations of fourteen 4-substituted 2,6-dimethylfuro[2,3-d]pyrimidines are reported. Four compounds (11-13, 15) inhibit vascular endothelial growth factor receptor-2 (VEGFR-2), platelet-derived growth factor receptor ß (PDGFR-ß), and target tubulin leading to cytotoxicity. Compound 11 has nanomolar potency, comparable to sunitinib and semaxinib, against tumor cell lines overexpressing VEGFR-2 and PDGFR-ß. Further, 11 binds at the colchicine site on tubulin, depolymerizes cellular microtubules and inhibits purified tubulin assembly and overcomes both ßIII-tubulin and P-glycoprotein-mediated drug resistance, and initiates mitotic arrest leading to apoptosis. In vivo, its HCl salt, 21, reduced tumor size and vascularity in xenograft and allograft murine models and was superior to docetaxel and sunitinib, without overt toxicity. Thus 21 affords potential combination chemotherapy in a single agent.
Asunto(s)
Compuestos de Anilina/farmacología , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Descubrimiento de Drogas , Microtúbulos/efectos de los fármacos , Neoplasias Experimentales/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/farmacología , Pirimidinas/farmacología , Proteínas Tirosina Quinasas Receptoras/antagonistas & inhibidores , Agua/química , Compuestos de Anilina/síntesis química , Compuestos de Anilina/química , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Femenino , Células HeLa , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Neoplasias Experimentales/patología , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/química , Pirimidinas/síntesis química , Pirimidinas/química , Proteínas Tirosina Quinasas Receptoras/metabolismo , Solubilidad , Relación Estructura-ActividadRESUMEN
Most cancer patients die with metastatic disease, thus, good models that recapitulate the natural process of metastasis including a dormancy period with micrometastatic cells would be beneficial in developing treatment strategies. Herein we report a model of natural metastasis that balances time to complete experiments with a reasonable dormancy period, which can be used to better study metastatic progression. The basis for the model is a 4T1 triple negative syngeneic breast cancer model without resection of the primary tumor. A cell titration from 500 to 15,000 GFP tagged 4T1 cells implanted into fat pad number four of immune proficient eight week female BALB/cJ mice optimized speed of the model while possessing metastatic processes including dormancy and beginning of reactivation. The frequency of primary tumors was less than 50% in animals implanted with 500-1500 cells. Although implantation with over 10,000 cells resulted in 100% primary tumor development, the tumors and macrometastases formed were highly aggressive, lacked dormancy, and offered no opportunity for treatment. Implantation of 7,500 cells resulted in >90% tumor take by 10 days; in 30-60 micrometastases in the lung (with many animals also having 2-30 brain micrometastases) two weeks post-implantation, with the first small macrometastases present at five weeks; many animals displaying macrometastases at five weeks and animals becoming moribund by six weeks post-implantation. Using the optimum of 7,500 cells the efficacy of a chemotherapeutic agent for breast cancer, doxorubicin, given at its maximal tolerated dose (MTD; 1 mg/kg weekly) was tested for an effect on metastasis. Doxorubicin treatment significantly reduced primary tumor growth and lung micrometastases but the number of macrometastases at experiment end was not significantly affected. This model should prove useful for development of drugs to target metastasis and to study the biology of metastasis.
Asunto(s)
Neoplasias de la Mama/patología , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/secundario , Metástasis de la Neoplasia/patología , Micrometástasis de Neoplasia/patología , Animales , Neoplasias de la Mama/tratamiento farmacológico , Línea Celular Tumoral , Progresión de la Enfermedad , Doxorrubicina/farmacología , Femenino , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Mamarias Experimentales/tratamiento farmacológico , Neoplasias Mamarias Experimentales/patología , Ratones , Ratones Endogámicos BALB C , Metástasis de la Neoplasia/tratamiento farmacológico , Micrometástasis de Neoplasia/tratamiento farmacológicoRESUMEN
Probestin is a potent aminopeptidase N (APN) inhibitor originally isolated from the bacterial culture broth. Here, we report probestin synthesis by solid phase peptide synthesis (SPPS) method and evaluated its activity to inhibit angiogenesis using a chicken embryo chorioallantoic membrane (CAM) assay and a CAM tumor xenograft model. Results from these studies demonstrate that probestin inhibits the angiogenic activity and tumor growth.
Asunto(s)
Inhibidores de la Angiogénesis/síntesis química , Inhibidores de la Angiogénesis/farmacología , Oligopéptidos/síntesis química , Oligopéptidos/farmacología , Inhibidores de la Angiogénesis/química , Animales , Neoplasias de la Mama/irrigación sanguínea , Neoplasias de la Mama/tratamiento farmacológico , Antígenos CD13/antagonistas & inhibidores , Línea Celular Tumoral , Embrión de Pollo , Membrana Corioalantoides/irrigación sanguínea , Femenino , Humanos , Ratones Endogámicos BALB C , Neovascularización Fisiológica/efectos de los fármacos , Oligopéptidos/química , Técnicas de Síntesis en Fase Sólida/métodos , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Six novel N(4)-phenylsubstituted-6-(2-pyridin-2-ylethyl)-7H-pyrrolo[2,3-d]pyrimidine-2,4-diamines and their N(2)-trimethylacetyl substituted analogs were synthesized as receptor tyrosine kinase (RTK) inhibitors. A microwave-mediated Sonogashira reaction was used as a key step for the synthesis of these compounds. Biological evaluation, in whole cell assays, showed that some analogs had remarkable inhibitory activity against a variety of RTKs and in particular cytotoxic activity against A431 tumor cells in culture. The inhibitory data against RTKs in this study demonstrated that variation of the 4-anilino substituents of these analogs dictates both potency and specificity of inhibitory activity against various RTKs. The study also supported the hypothesis that interaction of substituents on the 2-amino group with hydrophobic site-II provides an increase in potency. Compound 8 of this series was selected for evaluation in vivo in a B16-F10 syngeneic mouse tumor model and exhibited significant reduction in tumor growth rate, in tumor vascular density and in metastases to the lung compared to the control.
Asunto(s)
Inhibidores de la Angiogénesis/química , Antineoplásicos/química , Diseño de Fármacos , Inhibidores de Proteínas Quinasas/química , Pirimidinas/química , Pirroles/química , Proteínas Tirosina Quinasas Receptoras/antagonistas & inhibidores , Inhibidores de la Angiogénesis/uso terapéutico , Inhibidores de la Angiogénesis/toxicidad , Animales , Antineoplásicos/uso terapéutico , Antineoplásicos/toxicidad , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Humanos , Melanoma Experimental/tratamiento farmacológico , Ratones , Ratones Desnudos , Microondas , Inhibidores de Proteínas Quinasas/uso terapéutico , Inhibidores de Proteínas Quinasas/toxicidad , Pirimidinas/uso terapéutico , Pirimidinas/toxicidad , Pirroles/uso terapéutico , Pirroles/toxicidad , Proteínas Tirosina Quinasas Receptoras/metabolismo , Relación Estructura-ActividadRESUMEN
Inhibition of receptor tyrosine kinase (RTK) signaling pathways is an important area for the development of novel anticancer agents. Numerous multikinase inhibitors (MKIs) have been recently approved for the treatment of cancer. Vascular endothelial growth factor receptor-2 (VEGFR-2) is the principal mediator of tumor angiogenesis. In an effort to develop ATP-competitive VEGFR-2 selective inhibitors the 5-chloro-N(4)-substituted phenyl-9H-pyrimido[4,5-b]indole-2,4-diamine scaffold was designed. The synthesis of the target compounds involved N-(4,5-dichloro-9H-pyrimido[4,5-b]indol-2-yl)-2,2-dimethylpropanamide) as a common intermediate. A nucleophilic displacement of the 4-chloro group of the common intermediate by appropriately substituted anilines afforded the target compounds. Biological evaluation indicated that compound 5 is a potent and selective VEGFR-2 inhibitor comparable to sunitinib and semaxinib.
Asunto(s)
Inhibidores de la Angiogénesis/química , Diaminas/química , Indoles/química , Receptor 2 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Inhibidores de la Angiogénesis/síntesis química , Inhibidores de la Angiogénesis/farmacología , Línea Celular Tumoral , Diaminas/síntesis química , Diaminas/farmacología , Halogenación , Humanos , Indoles/síntesis química , Indoles/farmacología , Pirimidinas/síntesis química , Pirimidinas/química , Pirimidinas/farmacología , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismoRESUMEN
We designed, synthesized and evaluated 13 novel tricyclic indeno[2,1-d]pyrimidines as RTK inhibitors. These analogues were synthesized via a Dieckmann condensation of 1,2-phenylenediacetonitrile followed by cyclocondensation with guanidine carbonate to afford the 2-amino-3,9-dihydro-indeno[2,1-d]pyrimidin-4-one. Sulfonation of the 4-position followed by displacement with appropriately substituted anilines afforded the target compounds. These compounds were potent inhibitors of platelet-derived growth factor receptor ß (PDGFRß) and inhibited angiogenesis in the chicken embryo chorioallantonic membrane (CAM) assay compared to standards. In addition, compound 7 had a two digit nanomolar GI(50) against nine tumor cell lines, a submicromolar GI(50) against 29 of other tumor cell lines in the preclinical NCI 60 tumor cell line panel. Compound 7 also demonstrated significant in vivo inhibition of tumor growth and angiogenesis in a B16-F10 syngeneic mouse melanoma model.
Asunto(s)
Inhibidores de la Angiogénesis/química , Antineoplásicos/química , Indenos/química , Pirimidinas/química , Inhibidores de la Angiogénesis/uso terapéutico , Inhibidores de la Angiogénesis/toxicidad , Animales , Antineoplásicos/uso terapéutico , Antineoplásicos/toxicidad , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Embrión de Pollo , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Indenos/uso terapéutico , Indenos/toxicidad , Melanoma Experimental/tratamiento farmacológico , Ratones , Pirimidinas/uso terapéutico , Pirimidinas/toxicidad , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/antagonistas & inhibidores , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/metabolismoRESUMEN
With the goal of developing multitargeted receptor tyrosine kinase inhibitors that display potent inhibition against PDGFRß and VEGFR-2 we designed and synthesized eleven N(4)-(3-bromophenyl)-7-(substitutedbenzyl) pyrrolo[2,3-d]pyrimidines 9a-19a. These compounds were obtained from the key intermediate N(4)-(3-bromophenyl)-7H-pyrrolo[2,3-d]pyrimidine-2,4-diamine 29. Various arylmethyl groups were regiospecifically attached at the N7 of 29 via sodium hydride induced alkylation with substituted arylmethyl halides. Compounds 11a and 19a were potent dual inhibitors of PDGFRß and VEGFR-2. In a COLO-205, in vivo tumor mouse model 11a demonstrated inhibition of tumor growth, metastasis, and tumor angiogenesis that was better than or comparable to the standard compound TSU-68 (SU6668, 8).
Asunto(s)
Diseño de Fármacos , Inhibidores de Proteínas Quinasas/síntesis química , Pirimidinas/química , Pirroles/química , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/antagonistas & inhibidores , Receptor 2 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Animales , Sitios de Unión , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Humanos , Indoles/síntesis química , Indoles/farmacología , Indoles/uso terapéutico , Ratones , Ratones Desnudos , Simulación de Dinámica Molecular , Neoplasias/tratamiento farmacológico , Oxindoles , Propionatos/síntesis química , Propionatos/farmacología , Propionatos/uso terapéutico , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Estructura Terciaria de Proteína , Pirimidinas/farmacología , Pirimidinas/uso terapéutico , Pirroles/farmacología , Pirroles/uso terapéutico , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/metabolismo , Trasplante Heterólogo , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Six novel N(4)-substitutedphenyl-6-substitutedphenylmethyl-7H-pyrrolo[2,3-d]pyrimidine-2,4-diamines were synthesized as multiple receptor tyrosine kinase (RTK) inhibitors and antitumor agents. An improvement in the inhibitory potency against epidermal growth factor receptor (EGFR), vascular endothelial growth factor receptor 1 (VEGFR-1) and vascular endothelial growth factor receptor 2 (VEGFR-2) assays and in the A431 cellular proliferation assay was observed for compounds 8-13 over the previously reported 5-7. Three compounds (8, 9 and 13) demonstrated potent, multiple RTK inhibition and were more potent or equipotent compared to the lead compounds 5 and 7 and the standard compounds. Compounds 10 and 12 showed potent inhibition of VEGFR-2 over EGFR, platelet-derived growth factor receptor-ß (PDGFR-ß) and VEGFR-1. The results indicate that the RTK inhibitory profile could be modulated with slight variations to the N(4)-aryl-6-substitutedphenylmethyl-7H-pyrrolo[2,3-d]pyrimidine-2,4-diamino scaffold.
Asunto(s)
Diaminas/química , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Pirimidinas/química , Antineoplásicos/síntesis química , Antineoplásicos/química , Antineoplásicos/farmacología , Línea Celular Tumoral , Diaminas/síntesis química , Diaminas/farmacología , Activación Enzimática/efectos de los fármacos , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/metabolismo , Humanos , Inhibidores de Proteínas Quinasas/síntesis química , Receptor 1 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Receptor 1 de Factores de Crecimiento Endotelial Vascular/metabolismo , Receptor 2 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismoRESUMEN
A series of eight N(4)-phenylsubstituted-6-(2,4-dichlorophenylmethyl)-7H-pyrrolo[2,3-d]pyrimidine-2,4-diamines 8-15 were synthesized as vascular endothelial growth factor receptor-2 (VEGFR-2) inhibitors with varied substitutions in the phenyl ring of the 4-anilino moiety. In addition, five N(4)-phenylsubstituted-6-phenylmethylsubstituted-7H-pyrrolo[2,3-d]pyrimidin-4-amines 16-20 were synthesized to evaluate the importance of the 2-NH(2) moiety for multiple receptor tyrosine kinase (RTK) inhibition. Cyclocondensation of alpha-halomethylbenzylketones with 2,6-diamino-4-hydroxypyrimidine afforded 2-amino-6-(2,4-dichlorophenylmethyl)-3,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-one, 23 and reaction of alpha-bromomethylbenzylketones with ethylamidinoacetate followed by cyclocondensation with formamide afforded the 6-phenylmethylsubstituted-3,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-ones, 40-42, respectively. Chlorination of the 4-position and displacement with appropriate anilines afforded the target compounds 8-20. Compounds 8, 10 and 14 were potent VEGFR-2 inhibitors and were 100-fold, 40-fold and 8-fold more potent than the standard semaxanib, respectively. Previously synthesized multiple RTK inhibitor, 5 and the VEGFR-2 inhibitor 8 from this study, were chosen for further evaluation in a mouse orthotopic model of melanoma and showed significant inhibition of tumor growth, angiogenesis and metastasis.
Asunto(s)
Antineoplásicos/síntesis química , Diaminas/síntesis química , Pirimidinas/síntesis química , Receptor 2 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Inhibidores de la Angiogénesis/síntesis química , Inhibidores de la Angiogénesis/uso terapéutico , Animales , Antineoplásicos/uso terapéutico , Línea Celular Tumoral , Diaminas/uso terapéutico , Indoles/uso terapéutico , Masculino , Melanoma/prevención & control , Ratones , Ratones Desnudos , Estructura Molecular , Fosforilación/efectos de los fármacos , Pirimidinas/uso terapéutico , Pirimidinonas/química , Pirimidinonas/farmacología , Pirroles/uso terapéutico , Relación Estructura-ActividadRESUMEN
Trivalent arsenic [As(III)] is currently approved by the FDA for the treatment of chronic and acute leukemias. However, As(III) has also demonstrated damaging effects on human health, including development of cardiovascular disease, diabetes, and cancer. Further, As(III) is a potent angiogenic agent. In this context, curcumin, an active ingredient in the dietary agent turmeric, has demonstrated potent antiproliferative, antiinflammatory, and antiangiogenic properties. In this report, we have shown that both curcumin and turmeric inhibit expression of vascular endothelial growth factor in HCT-116 human colon cancer cells exposed to As(III). Further, in the chicken chorioallantoic membrane assay model, treatment with low As(III) concentrations results in extensive increase in blood vessel density, which, however, is reduced in the presence of curcumin or turmeric. Collectively, the findings reported here strongly suggest that turmeric and curcumin can dramatically attenuate the process of angiogenesis induced by low As(III) concentrations.
Asunto(s)
Inhibidores de la Angiogénesis/uso terapéutico , Arsénico/efectos adversos , Neoplasias del Colon/tratamiento farmacológico , Curcuma/química , Curcumina/uso terapéutico , Neovascularización Patológica/tratamiento farmacológico , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Animales , Arsénico/uso terapéutico , Embrión de Pollo , Humanos , Leucemia/tratamiento farmacológico , FitoterapiaRESUMEN
BACKGROUND: Chronic exposure to drinking water arsenic is a significant worldwide environmental health concern. Exposure to As is associated with an increased risk of lung disease, which may make it a unique toxicant, because lung toxicity is usually associated with inhalation rather than ingestion. OBJECTIVES: The goal of this study was to examine mRNA and protein expression changes in the lungs of mice exposed chronically to environmentally relevant concentrations of As in the food or drinking water, specifically examining the hypothesis that As may preferentially affect gene and protein expression related to immune function as part of its mechanism of toxicant action. METHODS: C57BL/6J mice fed a casein-based AIN-76A defined diet were exposed to 10 or 100 ppb As in drinking water or food for 5-6 weeks. RESULTS: Whole genome transcriptome profiling of animal lungs revealed significant alterations in the expression of many genes with functions in cell adhesion and migration, channels, receptors, differentiation and proliferation, and, most strikingly, aspects of the innate immune response. Confirmation of mRNA and protein expression changes in key genes of this response revealed that genes for interleukin 1beta, interleukin 1 receptor, a number of toll-like receptors, and several cytokines and cytokine receptors were significantly altered in the lungs of As-exposed mice. CONCLUSIONS: These findings indicate that chronic low-dose As exposure at the current U.S. drinking-water standard can elicit effects on the regulation of innate immunity, which may contribute to altered disease risk, particularly in lung.
Asunto(s)
Arsénico/toxicidad , Regulación de la Expresión Génica/efectos de los fármacos , Sistema Inmunológico/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Abastecimiento de Agua , Animales , Western Blotting , Líquido del Lavado Bronquioalveolar/química , Líquido del Lavado Bronquioalveolar/inmunología , Perfilación de la Expresión Génica , Pulmón/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
OBJECTIVE: The objective of the study was to investigate the effect of different periods of hyperglycemia on the reversal of endothelial dysfunction by glucose normalization and antioxidant therapy. RESEARCH DESIGN AND METHODS: Ten healthy subjects and three subgroups of 10 type 1 diabetic subjects were enrolled as follows: 1) patients within 1 month of diagnosis; 2) patients between 4.5 and 5.2 yr from diagnosis and with glycosylated hemoglobin levels 7% or greater since diagnosis; 3) patients between 4.8 and 5.4 yr from diagnosis and with glycosylated hemoglobin levels greater than 7% since diagnosis. Each patient participated in three experiments: 1) 24-h insulin treatment, achieving a near normalization of glycemia, together with the addition of the antioxidant vitamin C during the last 12 h; 2) 24-h vitamin C treatment with insulin treatment for the last 12 h; and 3) treatment with both vitamin C and insulin for 24 h. RESULTS: Endothelial function, as measured by flow-mediated vasodilation of the brachial artery and levels of nitrotyrosine, an oxidative stress marker, were normalized by each treatment in subgroups 1 and 2. In the third subgroup, neither glucose normalization nor vitamin C treatment alone was able to normalize endothelial dysfunction or oxidative stress. Combining insulin and vitamin C, however, normalized endothelial dysfunction and nitrotyrosine. CONCLUSIONS: This study suggests that long-lasting hyperglycemia in type 1 diabetic patients induces long-term alterations in endothelial cells, which may contribute to endothelial dysfunction and is interrupted only by both glucose and oxidative stress normalization.
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Diabetes Mellitus Tipo 1/fisiopatología , Endotelio Vascular/fisiopatología , Hiperglucemia/fisiopatología , Adulto , Ácido Ascórbico/uso terapéutico , Glucemia/análisis , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Femenino , Humanos , Insulina/uso terapéutico , Masculino , Estrés OxidativoRESUMEN
CONTEXT: The concept of a "metabolic memory," that is of diabetic vascular stresses persisting after glucose normalization, has been supported both in the laboratory and in the clinic and in both type 1 and type 2 diabetes. EVIDENCE ACQUISITION: Using PubMed, we searched for publications on diabetic micro- and macrovascular complications using terms such as persistence, prolongation, sustained, and "memory" and focusing on the mechanistic basis behind this metabolic memory. EVIDENCE SYNTHESIS: We found that as early as the mid-1980s this memory phenomenon was described in diabetic animals and isolated cells exposed to high glucose followed by normalized glucose and then, beginning around 2002, in results from large clinical trials such as the Diabetes Complications and Control Trial-Epidemiology of Diabetes Interventions and Complications and the United Kingdom Prospective Diabetes Study. Furthermore, mechanisms for propagating this memory appear focused on the nonenzymatic glycation of cellular proteins and lipids and on an excess of cellular reactive oxygen and nitrogen species, in particular originating at the level of glycated mitochondrial proteins and perhaps acting in concert with one another to maintain stress signaling independent of glucose levels. CONCLUSIONS: The emergence of this metabolic memory suggests the need for early aggressive treatment aiming to "normalize" metabolic control together perhaps with the addition of agents which reduce cellular reactive species and glycation in order to minimize long-term diabetic complications.
Asunto(s)
Glucemia/metabolismo , Complicaciones de la Diabetes/prevención & control , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Redes y Vías Metabólicas/fisiología , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/etiología , Enfermedades Cardiovasculares/metabolismo , Complicaciones de la Diabetes/metabolismo , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/complicaciones , Productos Finales de Glicación Avanzada/fisiología , Humanos , Modelos Biológicos , Estrés Oxidativo/fisiologíaRESUMEN
AIM: Data suggest that 2h hyperglycaemia during an OGTT is less predictive for cardiovascular disease of the glucose "spike" (the difference between the baseline glucose level and the "peak" hyperglycaemia during the test). METHODS: A euinsulinemic hyperglycaemic clamp at 10 and 15mmol/l glucose, with or without vitamin C, was given in increasing steps in diabetic and normal subjects. Moreover, a hyperglycaemic clamp, 10mmol/l, was performed in two groups of diabetic patients with different levels of fasting glycaemia. In both the experiments flow mediated dilation and nitrotyrosine were measured. RESULTS: Glucose at 10 and 15mmol/l resulted in a concentration-dependent induction of endothelial dysfunction and oxidative stress. Vitamin C counterbalanced this effect. The increase of glycaemia to 10mmol/l induced a significant endothelial dysfunction and increased nitrotyrosine in both the groups of diabetics with different fasting glycaemia. However, when the delta (the difference between the basal value and the peak value) for endothelial function and nitrotyrosine was evaluated, patients with lower basal values showed a worse outcome. CONCLUSIONS: Our data suggest that at the same level of hyperglycaemia the grading of the endothelial dysfunction is almost super imposable, but clearly worse in terms of delta from fasting glycaemia.