RESUMEN
Background: Life sciences research often turns out to be ineffective. Our aim was to develop a method for mapping repetitive research processes, detecting practice variations, and exploring inefficiencies. Methods: Three samples of R&I projects were used: companion diagnostics of cancer treatments, identification of COVID-19 variants, and COVID-19 vaccine development. Major steps involved: defined starting points, desired end points; measurement of transition times and success rates; exploration of variations, and recommendations for improved efficiency. Results: Over 50% of CDX developments failed to reach market simultaneously with new drugs. There were significant variations among phases of co-development (Bartlett test P<0.001). Length of time in vaccine development also shows variations (P<0.0001). Similarly, subject participation indicates unexplained variations in trials (Phase I: 489.7 (±461.8); Phase II: 857.3 (±450.1); Phase III: 35402 (±18079). Conclusion: Analysis of repetitive research processes can highlight inefficiencies and show ways to improve quality and productivity in life sciences.
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Based on knowledge of kinase switch-control inhibition and using a combination of structure-based drug design and standard medicinal chemistry principles, we identified a novel series of dihydropyrimidone-based CSF1R kinase inhibitors displaying exquisite selectivity for CSF1R versus a large panel of kinases and non-kinase protein targets. Starting with lead compound 3, an SAR optimization campaign led to the discovery of vimseltinib (DCC-3014; compound 20) currently undergoing clinical evaluation for the treatment of Tenosynovial Giant Cell Tumor (TGCT), a locally aggressive benign tumor associated with substantial morbidity. 2021 Elsevier ltd. All rights reserved.
Asunto(s)
Antineoplásicos , Tumor de Células Gigantes de las Vainas Tendinosas , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Receptor DCC , Tumor de Células Gigantes de las Vainas Tendinosas/tratamiento farmacológico , Tumor de Células Gigantes de las Vainas Tendinosas/patología , Humanos , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Tirosina Quinasas Receptoras , Receptor de Factor Estimulante de Colonias de MacrófagosRESUMEN
Based on the structure of an early lead identified in Deciphera's proprietary compound collection of switch control kinase inhibitors and using a combination of medicinal chemistry guided structure activity relationships and structure-based drug design, a novel series of potent acyl urea-based CSF1R inhibitors was identified displaying high selectivity for CSF1R versus the other members of the Type III receptor tyrosine kinase (RTK) family members (KIT, PDGFR-α, PDGFR-ß, and FLT3), VEGFR2 and MET. Based on in vitro biology, in vitro ADME and in vivo PK/PD studies, compound 10 was selected as an advanced lead for Deciphera's CSF1R research program.
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Proteínas Tirosina Quinasas Receptoras , Urea , Diseño de Fármacos , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Receptor beta de Factor de Crecimiento Derivado de Plaquetas , Relación Estructura-Actividad , Urea/química , Urea/farmacologíaRESUMEN
In this paper, we provide a brief overview of the history, organizational structure, and current operational state of our blended academic and community-model breast service. We review the challenges inherent to governance and management of a "matrix" organization practice model such as ours, and discuss the ways in which the leadership of our evolving blended practice are addressing those challenges collaboratively.
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Liderazgo , Modelos Organizacionales , HumanosRESUMEN
Macrophages can be co-opted to contribute to neoplastic, neurologic, and inflammatory diseases. Colony-stimulating factor 1 receptor (CSF1R)-dependent macrophages and other inflammatory cells can suppress the adaptive immune system in cancer and contribute to angiogenesis, tumor growth, and metastasis. CSF1R-expressing osteoclasts mediate bone degradation in osteolytic cancers and cancers that metastasize to bone. In the rare disease tenosynovial giant cell tumor (TGCT), aberrant CSF1 expression and production driven by a gene translocation leads to the recruitment and growth of tumors formed by CSF1R-dependent inflammatory cells. Small molecules and antibodies targeting the CSF1/CSF1R axis have shown promise in the treatment of TGCT and cancer, with pexidartinib recently receiving FDA approval for treatment of TGCT. Many small-molecule kinase inhibitors of CSF1R also inhibit the closely related kinases KIT, PDGFRA, PDGFRB, and FLT3, thus CSF1R suppression may be limited by off-target activity and associated adverse events. Vimseltinib (DCC-3014) is an oral, switch control tyrosine kinase inhibitor specifically designed to selectively and potently inhibit CSF1R by exploiting unique features of the switch control region that regulates kinase conformational activation. In preclinical studies, vimseltinib durably suppressed CSF1R activity in vitro and in vivo, depleted macrophages and other CSF1R-dependent cells, and resulted in inhibition of tumor growth and bone degradation in mouse cancer models. Translationally, in a phase I clinical study, vimseltinib treatment led to modulation of biomarkers of CSF1R inhibition and reduction in tumor burden in TGCT patients.
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Tumor de Células Gigantes de las Vainas Tendinosas/tratamiento farmacológico , Macrófagos/efectos de los fármacos , Inhibidores de Proteínas Quinasas/uso terapéutico , Adulto , Animales , Proliferación Celular , Estudios Cruzados , Modelos Animales de Enfermedad , Femenino , Humanos , Masculino , Ratones , Ratones Desnudos , Persona de Mediana Edad , Modelos Moleculares , Inhibidores de Proteínas Quinasas/farmacología , Ratas , Ratas Sprague-Dawley , Adulto JovenRESUMEN
CONCLUSIONS: A patient with end-stage renal disease on chronic dialysis was admitted to the hospital for renal transplantation evaluation. Blood type and antibody detection tests were performed. The antibody detection test results were positive. Initial antibody identification studies indicated the presence of a panagglutinin. The patient's autocontrol was negative. The antibody was subsequently iden-tified by a reference laboratory as anti-Ata (Augustine), which is an extremely rare antibody due to the high prevalence of Ata in the general population. A monocyte monolayer assay (MMA) was performed to assess the clinical significance of the antibody in the event that blood was needed for transfusion, and At(a-) RBCs were not available. The MMA results predicted the antibody to be capable of causing hemolysis in vivo. A brief historical review of the incidence and clinical significance of this antibody is included in this case report.
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Trasplante de Riñón , Antígenos de Grupos Sanguíneos , Transfusión Sanguínea , Hemólisis , Humanos , IsoanticuerposRESUMEN
Ripretinib (DCC-2618) was designed to inhibit the full spectrum of mutant KIT and PDGFRA kinases found in cancers and myeloproliferative neoplasms, particularly in gastrointestinal stromal tumors (GISTs), in which the heterogeneity of drug-resistant KIT mutations is a major challenge. Ripretinib is a "switch-control" kinase inhibitor that forces the activation loop (or activation "switch") into an inactive conformation. Ripretinib inhibits all tested KIT and PDGFRA mutants, and notably is a type II kinase inhibitor demonstrated to broadly inhibit activation loop mutations in KIT and PDGFRA, previously thought only achievable with type I inhibitors. Ripretinib shows efficacy in preclinical cancer models, and preliminary clinical data provide proof-of-concept that ripretinib inhibits a wide range of KIT mutants in patients with drug-resistant GISTs.
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Antineoplásicos/farmacología , Resistencia a Antineoplásicos/efectos de los fármacos , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-kit/genética , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/genética , Animales , Células CHO , Línea Celular , Línea Celular Tumoral , Cricetulus , Resistencia a Antineoplásicos/genética , Neoplasias Gastrointestinales/tratamiento farmacológico , Neoplasias Gastrointestinales/genética , Células HCT116 , Células Endoteliales de la Vena Umbilical Humana , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos NOD , Ratones Desnudos , Ratones SCID , Mutación/efectos de los fármacos , Mutación/genéticaRESUMEN
Tumor-infiltrating myeloid cells promote tumor progression by mediating angiogenesis, tumor cell intravasation, and metastasis, which can offset the effects of chemotherapy, radiation, and antiangiogenic therapy. Here, we show that the kinase switch control inhibitor rebastinib inhibits Tie2, a tyrosine kinase receptor expressed on endothelial cells and protumoral Tie2-expressing macrophages in mouse models of metastatic cancer. Rebastinib reduces tumor growth and metastasis in an orthotopic mouse model of metastatic mammary carcinoma through reduction of Tie2+ myeloid cell infiltration, antiangiogenic effects, and blockade of tumor cell intravasation mediated by perivascular Tie2Hi/Vegf-AHi macrophages in the tumor microenvironment of metastasis (TMEM). The antitumor effects of rebastinib enhance the efficacy of microtubule inhibiting chemotherapeutic agents, either eribulin or paclitaxel, by reducing tumor volume, metastasis, and improving overall survival. Rebastinib inhibition of angiopoietin/Tie2 signaling impairs multiple pathways in tumor progression mediated by protumoral Tie2+ macrophages, including TMEM-dependent dissemination and angiopoietin/Tie2-dependent angiogenesis. Rebastinib is a promising therapy for achieving Tie2 inhibition in cancer patients. Mol Cancer Ther; 16(11); 2486-501. ©2017 AACR.
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Neoplasias de la Mama/tratamiento farmacológico , Macrófagos/efectos de los fármacos , Neovascularización Patológica/tratamiento farmacológico , Tumores Neuroendocrinos/tratamiento farmacológico , Neoplasias Pancreáticas/tratamiento farmacológico , Pirazoles/farmacología , Piridinas/farmacología , Quinolinas/farmacología , Receptor TIE-2/antagonistas & inhibidores , Angiopoyetinas/antagonistas & inhibidores , Angiopoyetinas/genética , Animales , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Femenino , Humanos , Ratones , Neovascularización Patológica/genética , Neovascularización Patológica/patología , Tumores Neuroendocrinos/genética , Tumores Neuroendocrinos/patología , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patología , Pirazoles/uso terapéutico , Piridinas/uso terapéutico , Quinolinas/uso terapéutico , Receptor TIE-2/genética , Transducción de Señal/efectos de los fármacos , Microambiente Tumoral/efectos de los fármacosRESUMEN
CONCLUSIONS: A 32-year-old African-American woman with a history of sickle cell disease presented for surgical evaluation of left total hip arthroplasty due to avascular necrosis of the femoral head. In anticipation of a complex orthopedic procedure, pre-surgical blood work was ordered. The patient's Fenwal blood sample typed as group O, D+. Although the patient had a history of anti-Fya, the antibody identification was inconclusive, so the workup was sent to a reference laboratory. The patient was last transfused with red blood cells (RBCs) 2 years earlier, but had no history of transfusion reactions. Due to surgery, the patient's hemoglobin (Hb) decreased from 10.2 g/dL (preoperative) to 8.6 g/dL (postoperative). One unit of weakly crossmatch-incompatible Fy(a-), C-, E-, K-, and sickle cell hemoglobin S (HbS)-negative RBCs was transfused without incident, and the patient was discharged. Several days later, the reference lab reported two new specificities, anti-Joa and anti-Jkb. Fortunately, the transfused RBC unit was Jk(b-). Therefore, the crossmatch incompatibility was attributed to anti-Joa, which targets a high-prevalence antigen found in 100 percent of most populations. Two weeks after discharge, the patient returned in sickle vaso-occlusive pain crisis. The patient was clinically stable, but her Hb was 6.7 g/dL. One unit of Fy(a-), Jk(b-), C-, E-, K-, HbS- RBCs, which was weakly crossmatch-incompatible, was transfused. The following day, her Hb was unchanged, lactic acid dehydrogenase increased from 951 to 2464 U/L, potassium increased from 3.7 to 4.6 mEq/L, creatinine increased from 0.60 to 0.98 mg/dL, and the patient developed a 38.4°C fever. These findings are consistent with a delayed hemolytic transfusion reaction (DHTR), mediated by anti-Joa, occurring 2 weeks after the first RBC transfusion. Further care could not be provided because the patient left the hospital against medical advice. The purpose of this case study is to report findings consistent with a DHTR attributed to anti-Joa, an antibody with relatively unknown clinical significance.
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Incompatibilidad de Grupos Sanguíneos , Reacción a la Transfusión , Adulto , Tipificación y Pruebas Cruzadas Sanguíneas , Transfusión de Eritrocitos , Femenino , Humanos , IsoanticuerposRESUMEN
A vailable tyrosine kinase inhibitors for chronic myeloid leukemia bind in an adenosine 5'-triphosphate-binding pocket and are affected by evolving mutations that confer resistance. Rebastinib was identified as a switch control inhibitor of BCR-ABL1 and FLT3 and may be active against resistant mutations. A Phase 1, first-in-human, single-agent study investigated rebastinib in relapsed or refractory chronic or acute myeloid leukemia. The primary objectives were to investigate the safety of rebastinib and establish the maximum tolerated dose and recommended Phase 2 dose. Fifty-seven patients received treatment with rebastinib. Sixteen patients were treated using powder-in-capsule preparations at doses from 57 mg to 1200 mg daily, and 41 received tablet preparations at doses of 100 mg to 400 mg daily. Dose-limiting toxicities were dysarthria, muscle weakness, and peripheral neuropathy. The maximum tolerated dose was 150 mg tablets administered twice daily. Rebastinib was rapidly absorbed. Bioavailability was 3- to 4-fold greater with formulated tablets compared to unformulated capsules. Eight complete hematologic responses were achieved in 40 evaluable chronic myeloid leukemia patients, 4 of which had a T315I mutation. None of the 5 patients with acute myeloid leukemia responded. Pharmacodynamic analysis showed inhibition of phosphorylation of substrates of BCR-ABL1 or FLT3 by rebastinib. Although clinical activity was observed, clinical benefit was insufficient to justify continued development in chronic or acute myeloid leukemia. Pharmacodynamic analyses suggest that other kinases inhibited by rebastinib, such as TIE2, may be more relevant targets for the clinical development of rebastinib (clinicaltrials.gov Identifier:00827138).
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Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Leucemia Mieloide Aguda/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/administración & dosificación , Quinolinas/administración & dosificación , Adulto , Anciano , Anciano de 80 o más Años , Monitoreo de Drogas , Resistencia a Antineoplásicos/genética , Femenino , Proteínas de Fusión bcr-abl/genética , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia Mieloide Aguda/genética , Masculino , Dosis Máxima Tolerada , Persona de Mediana Edad , Mutación , Inhibidores de Proteínas Quinasas/efectos adversos , Inhibidores de Proteínas Quinasas/farmacocinética , Quinolinas/efectos adversos , Quinolinas/farmacocinética , Resultado del Tratamiento , Adulto JovenRESUMEN
LY3009120 is a pan-RAF and RAF dimer inhibitor that inhibits all RAF isoforms and occupies both protomers in RAF dimers. Biochemical and cellular analyses revealed that LY3009120 inhibits ARAF, BRAF, and CRAF isoforms with similar affinity, while vemurafenib or dabrafenib have little or modest CRAF activity compared to their BRAF activities. LY3009120 induces BRAF-CRAF dimerization but inhibits the phosphorylation of downstream MEK and ERK, suggesting that it effectively inhibits the kinase activity of BRAF-CRAF heterodimers. Further analyses demonstrated that LY3009120 also inhibits various forms of RAF dimers including BRAF or CRAF homodimers. Due to these unique properties, LY3009120 demonstrates minimal paradoxical activation, inhibits MEK1/2 phosphorylation, and exhibits anti-tumor activities across multiple models carrying KRAS, NRAS, or BRAF mutation.
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Antineoplásicos/farmacología , Neoplasias/tratamiento farmacológico , Compuestos de Fenilurea/farmacología , Isoformas de Proteínas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas B-raf/antagonistas & inhibidores , Proteínas Proto-Oncogénicas B-raf/genética , Pirimidinas/farmacología , Proteínas ras/genética , Línea Celular Tumoral , Dimerización , Humanos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/genética , Proteínas Quinasas Activadas por Mitógenos/genética , Mutación/efectos de los fármacos , Mutación/genética , Neoplasias/genética , Fosforilación/efectos de los fármacos , Fosforilación/genética , Isoformas de Proteínas/genética , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-raf/genética , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genéticaRESUMEN
Altiratinib (DCC-2701) was designed based on the rationale of engineering a single therapeutic agent able to address multiple hallmarks of cancer (1). Specifically, altiratinib inhibits not only mechanisms of tumor initiation and progression, but also drug resistance mechanisms in the tumor and microenvironment through balanced inhibition of MET, TIE2 (TEK), and VEGFR2 (KDR) kinases. This profile was achieved by optimizing binding into the switch control pocket of all three kinases, inducing type II inactive conformations. Altiratinib durably inhibits MET, both wild-type and mutated forms, in vitro and in vivo. Through its balanced inhibitory potency versus MET, TIE2, and VEGFR2, altiratinib provides an agent that inhibits three major evasive (re)vascularization and resistance pathways (HGF, ANG, and VEGF) and blocks tumor invasion and metastasis. Altiratinib exhibits properties amenable to oral administration and exhibits substantial blood-brain barrier penetration, an attribute of significance for eventual treatment of brain cancers and brain metastases.
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Aminopiridinas/farmacología , Anilidas/farmacología , Resistencia a Antineoplásicos , Neovascularización Patológica , Proteínas Proto-Oncogénicas c-met/antagonistas & inhibidores , Receptor TIE-2/antagonistas & inhibidores , Microambiente Tumoral , Receptor 2 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Aminopiridinas/química , Anilidas/química , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Bevacizumab/química , Bevacizumab/farmacología , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Diseño de Fármacos , Quimioterapia Combinada , Femenino , Factor de Crecimiento de Hepatocito/metabolismo , Humanos , Concentración 50 Inhibidora , Melanoma Experimental , Ratones , Modelos Moleculares , Conformación Molecular , Monocitos/efectos de los fármacos , Monocitos/metabolismo , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas B-raf/antagonistas & inhibidores , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas B-raf/metabolismo , Proteínas Proto-Oncogénicas c-met/química , Proteínas Proto-Oncogénicas c-met/metabolismo , Receptor TIE-2/metabolismo , Proteínas Recombinantes , Células del Estroma/efectos de los fármacos , Células del Estroma/metabolismo , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The RAS-RAF-MEK-MAPK cascade is an essential signaling pathway, with activation typically mediated through cell surface receptors. The kinase inhibitors vemurafenib and dabrafenib, which target oncogenic BRAF V600E, have shown significant clinical efficacy in melanoma patients harboring this mutation. Because of paradoxical pathway activation, both agents were demonstrated to promote growth and metastasis of tumor cells with RAS mutations in preclinical models and are contraindicated for treatment of cancer patients with BRAF WT background, including patients with KRAS or NRAS mutations. In order to eliminate the issues associated with paradoxical MAPK pathway activation and to provide therapeutic benefit to patients with RAS mutant cancers, we sought to identify a compound not only active against BRAF V600E but also wild type BRAF and CRAF. On the basis of its superior in vitro and in vivo profile, compound 13 was selected for further development and is currently being evaluated in phase I clinical studies.
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Antineoplásicos/química , Antineoplásicos/farmacología , Compuestos de Fenilurea/química , Compuestos de Fenilurea/farmacología , Proteínas Proto-Oncogénicas B-raf/genética , Pirimidinas/química , Pirimidinas/farmacología , Proteínas ras/metabolismo , Animales , Antineoplásicos/síntesis química , Antineoplásicos/farmacocinética , Disponibilidad Biológica , Línea Celular Tumoral/efectos de los fármacos , Técnicas de Química Sintética , Perros , Femenino , Semivida , Humanos , Masculino , Ratones Desnudos , Terapia Molecular Dirigida , Mutación , Compuestos de Fenilurea/síntesis química , Compuestos de Fenilurea/farmacocinética , Proteínas Proto-Oncogénicas B-raf/antagonistas & inhibidores , Proteínas Proto-Oncogénicas B-raf/metabolismo , Proteínas Proto-Oncogénicas c-raf/metabolismo , Pirimidinas/síntesis química , Pirimidinas/farmacocinética , Ratas Sprague-Dawley , Relación Estructura-Actividad , Ensayos Antitumor por Modelo de Xenoinjerto , Proteínas ras/genéticaRESUMEN
A 62-year-old Filipino man with a history of chronic obstructive pulmonary disease, hypertension, and hyperlipidemia was admitted to the emergency department at Hospital A with recurrent fevers, weakness, and jaundice. The patient was evaluated and eventually discharged with a diagnosis of possible drug-induced hepatitis. One month later, the patient was admitted to Hospital B for recurrent fevers and weakness. The patient's hemoglobin was 3.8 g/dL. Six units of packed red blood cells (RBCs) were ordered for transfusion. The patient's sample typed as group B, D+, and the antibody screen was negative. All six units of packed RBCs appeared compatible (at immediate spin) and were transfused to the patient. His hemoglobin level 4 days post-transfusion was 9.3 g/dL, and the patient was discharged. The patient returned after a week for follow-up and his hemoglobin was found to have dropped to 8.5 g/dL, which continued to fall until it reached 7.0 g/dL. Additional packed RBCs were ordered for transfusion. during subsequent pre-transfusion compatibility testing, the antibody screen was found to be positive (all screening cells reactive at the antihuman globulin phase). An antibody identification panel was performed.The patient's serum was found to react with all panel cells tested, including the autocontrol tube. A direct antiglobulin test revealed the presence of both anti-IgG and anti-C3 coating the patient's RBCs. The specimen was then sent to a reference laboratory for further testing. Results from the reference lab testing revealed the presence of anti-Jk3 in the patient's serum. the patient was placed on steroids, and his reticulocyte count increased with no further signs of extravascular hemolysis. No additional transfusions were necessary. he was eventually discharged with a hemoglobin of 13.6 g/dL. the purpose of this case study is to report the findings of an extremely rare but clinically significant antibody, anti-Jk3.
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Anticuerpos Antiidiotipos/inmunología , Anticuerpos/inmunología , Complemento C3/inmunología , Sistema del Grupo Sanguíneo de Kidd/inmunología , Anticuerpos/sangre , Anticuerpos Antiidiotipos/sangre , Prueba de Coombs/métodos , Transfusión de Eritrocitos/métodos , Humanos , Masculino , Persona de Mediana Edad , FilipinasRESUMEN
According to the American Heart Association, cardiovascular disease accounts for more than one third of all deaths in the United States. 1 The purpose of this retrospective case-control study was to determine which sample taken in a sequential draw was most important in diagnosing an acute myocardial infarction (AMI). One-hundred subjects were selected from a convenience sample. The "risk" of AMI diagnosis was modeled using binary multiple logistic regression. Overall, 78% (39 out of 50 cases) were diagnosed with an AMI at Tinitiai. Clearly, the initial cTnI assay is the most critical of the four sequential time points for the accurate assessment of the presence or absence of an AMI. Most importantly, sequential troponin testing increased the ability to diagnose AMI by 10-fold.
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Infarto del Miocardio/sangre , Infarto del Miocardio/diagnóstico , Troponina I/sangre , Adulto , Anciano , Estudios de Casos y Controles , Electrocardiografía , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/epidemiología , Estudios Retrospectivos , Factores de RiesgoRESUMEN
Acquired resistance to ABL1 tyrosine kinase inhibitors (TKIs) through ABL1 kinase domain mutations, particularly the gatekeeper mutant T315I, is a significant problem for patients with chronic myeloid leukemia (CML). Using structure-based drug design, we developed compounds that bind to residues (Arg386/Glu282) ABL1 uses to switch between inactive and active conformations. The lead "switch-control" inhibitor, DCC-2036, potently inhibits both unphosphorylated and phosphorylated ABL1 by inducing a type II inactive conformation, and retains efficacy against the majority of clinically relevant CML-resistance mutants, including T315I. DCC-2036 inhibits BCR-ABL1(T315I)-expressing cell lines, prolongs survival in mouse models of T315I mutant CML and B-lymphoblastic leukemia, and inhibits primary patient leukemia cells expressing T315I in vitro and in vivo, supporting its clinical development in TKI-resistant Ph(+) leukemia.
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Proteínas de Fusión bcr-abl/antagonistas & inhibidores , Mutación , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Diseño de Fármacos , Proteínas de Fusión bcr-abl/química , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Masculino , Ratones , Ratones Endogámicos BALB C , Conformación Proteica , Proteínas Tirosina Quinasas/químicaRESUMEN
Acquired point mutations within the BCR-ABL kinase domain represent a common mechanism of resistance to ABL inhibitor therapy in patients with chronic myeloid leukemia (CML). The BCR-ABL(T315I) mutant is highly resistant to imatinib, nilotinib, and dasatinib, and is frequently detected in relapsed patients. This critical gap in resistance coverage drove development of DCC-2036, an ABL inhibitor that binds the switch control pocket involved in conformational regulation of the kinase domain. We evaluated the efficacy of DCC-2036 against BCR-ABL(T315I) and other mutants in cellular and biochemical assays and conducted cell-based mutagenesis screens. DCC-2036 inhibited autophosphorylation of ABL and ABL(T315I) enzymes, and this activity was consistent with selective efficacy against Ba/F3 cells expressing BCR-ABL (IC(50): 19 nmol/L), BCR-ABL(T315I) (IC(50): 63 nmol/L), and most kinase domain mutants. Ex vivo exposure of CML cells from patients harboring BCR-ABL or BCR-ABL(T315I) to DCC-2036 revealed marked inhibition of colony formation and reduced phosphorylation of the direct BCR-ABL target CrkL. Cell-based mutagenesis screens identified a resistance profile for DCC-2036 centered around select P-loop mutations (G250E, Q252H, Y253H, E255K/V), although a concentration of 750 nmol/L DCC-2036 suppressed the emergence of all resistant clones. A decreased concentration of DCC-2036 (160 nmol/L) in dual combination with either nilotinib or dasatinib achieved the same zero outgrowth result. Further screens for resistance due to BCR-ABL compound mutations (two mutations in the same clone) identified BCR-ABL(E255V / T315I) as the most resistant mutant. Taken together, these findings support continued evaluation of DCC-2036 as an important new agent for treatment-refractory CML.
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Genes abl , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Mutación Puntual , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-abl/antagonistas & inhibidores , Quinolinas/farmacología , Antineoplásicos/farmacología , Benzamidas , Línea Celular Tumoral , Resistencia a Antineoplásicos , Proteínas de Fusión bcr-abl/genética , Humanos , Mesilato de Imatinib , Células K562 , Leucemia Mielógena Crónica BCR-ABL Positiva/enzimología , Fosforilación , Piperazinas/farmacología , Pirimidinas/farmacologíaRESUMEN
Switch control pocket inhibitors of p38-alpha kinase are described. Durable type II inhibitors were designed which bind to arginines (Arg67 or Arg70) that function as key residues for mediating phospho-threonine 180 dependant conformational fluxing of p38-alpha from an inactive type II state to an active type I state. Binding to Arg70 in particular led to potent inhibitors, exemplified by DP-802, which also exhibited high kinase selectivity. Binding to Arg70 obviated the requirement for binding into the ATP Hinge region. X-ray crystallography revealed that DP-802 and analogs induce an enhanced type II conformation upon binding to either the unphosphorylated or the doubly phosphorylated form of p38-alpha kinase.
Asunto(s)
Adenosina Trifosfato/química , Proteína Quinasa 14 Activada por Mitógenos/antagonistas & inhibidores , Compuestos de Fenilurea/química , Inhibidores de Proteínas Quinasas/química , Pirazoles/química , Sitios de Unión , Simulación por Computador , Cristalografía por Rayos X , Células HeLa , Humanos , Cinética , Proteína Quinasa 14 Activada por Mitógenos/metabolismo , Compuestos de Fenilurea/síntesis química , Compuestos de Fenilurea/farmacología , Fosforilación , Unión Proteica , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacología , Pirazoles/síntesis química , Pirazoles/farmacología , Relación Estructura-ActividadRESUMEN
For ultra-high-throughput screening, 10-30 nl of compound dissolved in 75% dimethyl sulfoxide (DMSO)/25% water (vol/vol) is spotted into 1,536- and 3,456-well ChemLib plates (Aurora Biotechnologies, Carlsbad, CA) and stored appropriately for a short time before screening. Although this practice eliminates the compound plating bottleneck, plated volumes of DMSO slowly evaporate from assay wells if plates are not properly stored in the interim. Since many assays are sensitive to DMSO concentrations, even slight evaporation may cause intra-plate variation and thus decrease assay quality. Using a cytochrome P450 3A4 Vivid Blue assay (Invitrogen, Carlsbad), we investigated the rate, pattern, and quantity of evaporation over a 1-year time frame to identify best practices for long-term (i.e., 6 months or greater) storage of assay-ready compound plates. Our findings regarding evaporation at plate edges indicate that nanospots preplated in ChemLib 1,536- or 3,456-well plates are best stored at -80 degrees C, in a bag, with or without the outer evaporation wells filled or at -20 degrees C, in a bag, with evaporation wells filled.
Asunto(s)
Evaluación Preclínica de Medicamentos/métodos , Fluorometría/instrumentación , Fluorometría/métodos , Preservación Biológica/métodos , Bioensayo , Citocromo P-450 CYP3A/metabolismo , Dimetilsulfóxido/química , Dimetilsulfóxido/farmacología , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos/tendencias , Colorantes Fluorescentes/química , Humedad , Indicadores y Reactivos/química , Nanosferas/análisis , Nanosferas/química , Refrigeración , Robótica , Solventes/química , Temperatura , Factores de Tiempo , VolatilizaciónRESUMEN
The search for novel antibiotics to combat the growing threat of resistance has led researchers to screen libraries with coupled transcription and translation systems. In these systems, a bacterial cell lysate supplies the proteins necessary for transcription and translation, a plasmid encoding a reporter protein is added as a template, and a complex mixture of amino acids and cofactors is added to supply building blocks and energy to the assay. Firefly luciferase is typically used as the reporter protein in high-throughput screens because the luminescent signal is strong and, since bacterial lysates contain no luciferase, the background is negligible. The typical coupled transcription and translation assay is sensitive to inhibitors of RNA polymerase and to compounds that bind tightly to the ribosome. We have found a way to increase the information content of the screen by making the assay more sensitive to inhibitors of tRNA synthetases. Restricting the concentration of amino acids added to the reaction mixture allows the simultaneous screening of multiple tRNA synthetase enzymes along with the classic transcription and translation targets. In addition, this assay can be used as a convenient way to determine if an antibacterial compound of unknown mechanism inhibits translation through inhibition of a tRNA synthetase, and to identify which synthetase is the target.