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1.
Blood Adv ; 5(14): 2839-2851, 2021 07 27.
Artículo en Inglés | MEDLINE | ID: mdl-34283174

RESUMEN

Individuals with monogenic disorders can experience variable phenotypes that are influenced by genetic variation. To investigate this in sickle cell disease (SCD), we performed whole-genome sequencing (WGS) of 722 individuals with hemoglobin HbSS or HbSß0-thalassemia from Baylor College of Medicine and from the St. Jude Children's Research Hospital Sickle Cell Clinical Research and Intervention Program (SCCRIP) longitudinal cohort study. We developed pipelines to identify genetic variants that modulate sickle hemoglobin polymerization in red blood cells and combined these with pain-associated variants to build a polygenic score (PGS) for acute vaso-occlusive pain (VOP). Overall, we interrogated the α-thalassemia deletion -α3.7 and 133 candidate single-nucleotide polymorphisms (SNPs) across 66 genes for associations with VOP in 327 SCCRIP participants followed longitudinally over 6 years. Twenty-one SNPs in 9 loci were associated with VOP, including 3 (BCL11A, MYB, and the ß-like globin gene cluster) that regulate erythrocyte fetal hemoglobin (HbF) levels and 6 (COMT, TBC1D1, KCNJ6, FAAH, NR3C1, and IL1A) that were associated previously with various pain syndromes. An unweighted PGS integrating all 21 SNPs was associated with the VOP event rate (estimate, 0.35; standard error, 0.04; P = 5.9 × 10-14) and VOP event occurrence (estimate, 0.42; standard error, 0.06; P = 4.1 × 10-13). These associations were stronger than those of any single locus. Our findings provide insights into the genetic modulation of VOP in children with SCD. More generally, we demonstrate the utility of WGS for investigating genetic contributions to the variable expression of SCD-associated morbidities.


Asunto(s)
Anemia de Células Falciformes , Hemoglobina Fetal , Anemia de Células Falciformes/complicaciones , Anemia de Células Falciformes/genética , Niño , Hemoglobina Fetal/genética , Humanos , Estudios Longitudinales , Dolor , Polimorfismo de Nucleótido Simple
2.
Clin Cancer Res ; 24(7): 1654-1666, 2018 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-29301833

RESUMEN

Purpose: Curing all children with brain tumors will require an understanding of how each subtype responds to conventional treatments and how best to combine existing and novel therapies. It is extremely challenging to acquire this knowledge in the clinic alone, especially among patients with rare tumors. Therefore, we developed a preclinical brain tumor platform to test combinations of conventional and novel therapies in a manner that closely recapitulates clinic trials.Experimental Design: A multidisciplinary team was established to design and conduct neurosurgical, fractionated radiotherapy and chemotherapy studies, alone or in combination, in accurate mouse models of supratentorial ependymoma (SEP) subtypes and choroid plexus carcinoma (CPC). Extensive drug repurposing screens, pharmacokinetic, pharmacodynamic, and efficacy studies were used to triage active compounds for combination preclinical trials with "standard-of-care" surgery and radiotherapy.Results: Mouse models displayed distinct patterns of response to surgery, irradiation, and chemotherapy that varied with tumor subtype. Repurposing screens identified 3-hour infusions of gemcitabine as a relatively nontoxic and efficacious treatment of SEP and CPC. Combination neurosurgery, fractionated irradiation, and gemcitabine proved significantly more effective than surgery and irradiation alone, curing one half of all animals with aggressive forms of SEP.Conclusions: We report a comprehensive preclinical trial platform to assess the therapeutic activity of conventional and novel treatments among rare brain tumor subtypes. It also enables the development of complex, combination treatment regimens that should deliver optimal trial designs for clinical testing. Postirradiation gemcitabine infusion should be tested as new treatments of SEP and CPC. Clin Cancer Res; 24(7); 1654-66. ©2018 AACR.


Asunto(s)
Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/terapia , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacología , Evaluación Preclínica de Medicamentos/métodos , Humanos , Ratones , Ratones Desnudos , Resultado del Tratamiento , Gemcitabina
3.
Cancer Cell ; 29(4): 508-522, 2016 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-27050100

RESUMEN

The childhood brain tumor, medulloblastoma, includes four subtypes with very different prognoses. Here, we show that paracrine signals driven by mutant ß-catenin in WNT-medulloblastoma, an essentially curable form of the disease, induce an aberrant fenestrated vasculature that permits the accumulation of high levels of intra-tumoral chemotherapy and a robust therapeutic response. In contrast, SHH-medulloblastoma, a less curable disease subtype, contains an intact blood brain barrier, rendering this tumor impermeable and resistant to chemotherapy. The medulloblastoma-endothelial cell paracrine axis can be manipulated in vivo, altering chemotherapy permeability and clinical response. Thus, medulloblastoma genotype dictates tumor vessel phenotype, explaining in part the disparate prognoses among medulloblastoma subtypes and suggesting an approach to enhance the chemoresponsiveness of other brain tumors.


Asunto(s)
Barrera Hematoencefálica , Neoplasias Cerebelosas/genética , Meduloblastoma/genética , Animales , Antineoplásicos/farmacocinética , Proteínas Portadoras/fisiología , Neoplasias Cerebelosas/irrigación sanguínea , Neoplasias Cerebelosas/clasificación , Neoplasias Cerebelosas/tratamiento farmacológico , Neoplasias Cerebelosas/metabolismo , Medios de Cultivo Condicionados/farmacología , Modelos Animales de Enfermedad , Resistencia a Antineoplásicos/fisiología , Endotelio Vascular/metabolismo , Endotelio Vascular/ultraestructura , Estudios de Asociación Genética , Vectores Genéticos/uso terapéutico , Genotipo , Transportador de Glucosa de Tipo 1/fisiología , Humanos , Meduloblastoma/irrigación sanguínea , Meduloblastoma/clasificación , Meduloblastoma/tratamiento farmacológico , Meduloblastoma/metabolismo , Proteínas de la Membrana/fisiología , Ratones , Ratones Transgénicos , Proteínas de Neoplasias/fisiología , Comunicación Paracrina/efectos de los fármacos , Pericitos/patología , Proteínas Recombinantes de Fusión/metabolismo , Uniones Estrechas/ultraestructura , Transducción Genética , Vincristina/farmacocinética , Vincristina/uso terapéutico , Proteínas Wnt/genética , Proteínas Wnt/fisiología , Vía de Señalización Wnt/efectos de los fármacos
4.
Drug Metab Dispos ; 44(4): 591-4, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26802130

RESUMEN

3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors were potent hits against a mouse ependymoma cell line, but their effectiveness against central nervous system tumors will depend on their ability to cross the blood-brain barrier and attain a sufficient exposure at the tumor. Among 3-hydroxy-3-methylglutaryl coenzyme A inhibitors that had activity in vitro, we prioritized simvastatin (SV) as the lead compound for preclinical pharmacokinetic studies based on its potential for central nervous system penetration as determined from in silico models. Furthermore, we performed systemic plasma disposition and cerebral microdialysis studies of SV (100 mg/kg, p.o.) in a murine model of ependymoma to characterize plasma and tumor extracellular fluid (tECF) pharmacokinetic properties. The murine dosage of SV (100 mg/kg, p.o.) was equivalent to the maximum tolerated dose in patients (7.5 mg/kg, p.o.) based on equivalent plasma exposure of simvastatin acid (SVA) between the two species. SV is rapidly metabolized in murine plasma with 15 times lower exposure compared with human plasma. SVA exposure in tECF was <33.8 ± 11.9 µg/l per hour, whereas the tumor to plasma partition coefficient of SVA was <0.084 ± 0.008. Compared with in vitro washout IC50 values, we did not achieve sufficient exposure of SVA in tECF to suggest tumor growth inhibition; therefore, SV was not carried forward in subsequent preclinical efficacy studies.


Asunto(s)
Neoplasias del Sistema Nervioso Central/metabolismo , Citotoxinas/administración & dosificación , Citotoxinas/metabolismo , Microdiálisis/métodos , Simvastatina/análogos & derivados , Animales , Barrera Hematoencefálica/efectos de los fármacos , Barrera Hematoencefálica/metabolismo , Línea Celular Tumoral , Neoplasias del Sistema Nervioso Central/tratamiento farmacológico , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/metabolismo , Evaluación Preclínica de Medicamentos/métodos , Ratones , Ratones Desnudos , Simvastatina/administración & dosificación , Simvastatina/metabolismo
5.
J Neurooncol ; 126(2): 225-34, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26518542

RESUMEN

Chemotherapies active in preclinical studies frequently fail in the clinic due to lack of efficacy, which limits progress for rare cancers since only small numbers of patients are available for clinical trials. Thus, a preclinical drug development pipeline was developed to prioritize potentially active regimens for pediatric brain tumors spanning from in vitro drug screening, through intracranial and intra-tumoral pharmacokinetics to in vivo efficacy studies. Here, as an example of the pipeline, data are presented for the combination of 5-fluoro-2'-deoxycytidine and tetrahydrouridine in three pediatric brain tumor models. The in vitro activity of nine novel therapies was tested against tumor spheres derived from faithful mouse models of Group 3 medulloblastoma, ependymoma, and choroid plexus carcinoma. Agents with the greatest in vitro potency were then subjected to a comprehensive series of in vivo pharmacokinetic (PK) and pharmacodynamic (PD) studies culminating in preclinical efficacy trials in mice harboring brain tumors. The nucleoside analog 5-fluoro-2'-deoxycytidine (FdCyd) markedly reduced the proliferation in vitro of all three brain tumor cell types at nanomolar concentrations. Detailed intracranial PK studies confirmed that systemically administered FdCyd exceeded concentrations in brain tumors necessary to inhibit tumor cell proliferation, but no tumor displayed a significant in vivo therapeutic response. Despite promising in vitro activity and in vivo PK properties, FdCyd is unlikely to be an effective treatment of pediatric brain tumors, and therefore was deprioritized for the clinic. Our comprehensive and integrated preclinical drug development pipeline should reduce the attrition of drugs in clinical trials.


Asunto(s)
Antineoplásicos/administración & dosificación , Neoplasias Encefálicas/tratamiento farmacológico , Encéfalo/efectos de los fármacos , Desoxicitidina/análogos & derivados , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos/métodos , Tetrahidrouridina/administración & dosificación , Animales , Antineoplásicos/sangre , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapéutico , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Desoxicitidina/administración & dosificación , Desoxicitidina/sangre , Desoxicitidina/farmacocinética , Desoxicitidina/uso terapéutico , Relación Dosis-Respuesta a Droga , Epigénesis Genética/efectos de los fármacos , Ratones , Ratones Desnudos , Tetrahidrouridina/sangre , Tetrahidrouridina/farmacocinética , Tetrahidrouridina/uso terapéutico
6.
Neuro Oncol ; 17(12): 1620-7, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26541630

RESUMEN

BACKGROUND: We report a phase I study to examine the pharmacokinetics, safety, and recommended dosage of weekly intravenous bolus 5-fluorouracil (5-FU) in children and young adults with recurrent ependymoma. METHODS: Patients 22 years of age or less with recurrent ependymoma were treated with bolus dosage 5-FU weekly for 4 weeks followed by a 2-week rest period, defining one cycle. Patients could continue on therapy for 16 cycles. The starting 5-FU dosage was 500 mg/m(2). Dose-limiting toxicity was determined after one cycle. Patients were initially enrolled according to a rolling-6 design; subsequent dose re-escalation phase was based on a 3 + 3 design. RESULTS: We treated patients at 400 (n = 6), 500 (n = 15), and 650 (n = 5) mg/m(2), with de-escalation due to toxicity. Twenty-three of twenty-six patients enrolled were evaluable. Five patients experienced grade 4 neutropenia (n = 2: 650 mg/m(2); n = 3: 500 mg/m(2)). One patient experienced grade 3 diarrhea. At 500 mg/m(2), the median 5-FU maximal concentration, AUC0-∞, and alpha half-life were 825 µM, 205 µM × h, and 9.9 min, respectively. Interim analysis revealed an association between hematologic toxicity and prior number of chemotherapeutic regimens (P = .03). The study was amended to re-escalate the dosage in a less heavily pretreated cohort of patients. CONCLUSIONS: These phase I clinical data provide initial pharmacokinetic parameters to describe i.v. bolus 5-FU disposition in children with recurrent ependymoma. Tumor exposures effective in preclinical testing can be achieved with tolerable bolus dosages in patients. Bolus 5-FU is well tolerated and possesses antitumor activity.


Asunto(s)
Antimetabolitos Antineoplásicos/farmacocinética , Antimetabolitos Antineoplásicos/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Ependimoma/tratamiento farmacológico , Fluorouracilo/farmacocinética , Fluorouracilo/uso terapéutico , Adolescente , Adulto , Antimetabolitos Antineoplásicos/administración & dosificación , Antimetabolitos Antineoplásicos/efectos adversos , Niño , Preescolar , Relación Dosis-Respuesta a Droga , Fluorouracilo/administración & dosificación , Fluorouracilo/efectos adversos , Humanos , Resultado del Tratamiento , Adulto Joven
7.
Nat Genet ; 47(8): 878-87, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26075792

RESUMEN

Cancers are characterized by non-random chromosome copy number alterations that presumably contain oncogenes and tumor-suppressor genes (TSGs). The affected loci are often large, making it difficult to pinpoint which genes are driving the cancer. Here we report a cross-species in vivo screen of 84 candidate oncogenes and 39 candidate TSGs, located within 28 recurrent chromosomal alterations in ependymoma. Through a series of mouse models, we validate eight new ependymoma oncogenes and ten new ependymoma TSGs that converge on a small number of cell functions, including vesicle trafficking, DNA modification and cholesterol biosynthesis, identifying these as potential new therapeutic targets.


Asunto(s)
Ependimoma/genética , Genes Supresores de Tumor , Predisposición Genética a la Enfermedad/genética , Oncogenes/genética , Animales , Células Cultivadas , Aberraciones Cromosómicas , Variaciones en el Número de Copia de ADN , Ependimoma/metabolismo , Femenino , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Células HEK293 , Humanos , Estimación de Kaplan-Meier , Masculino , Ratones Desnudos , Ratones Transgénicos , Microscopía Confocal , Neoplasias Experimentales/genética , Neoplasias Experimentales/metabolismo , Células-Madre Neurales/metabolismo , Células-Madre Neurales/trasplante , Análisis de Secuencia por Matrices de Oligonucleótidos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transfección
8.
Cancer Chemother Pharmacol ; 75(5): 897-906, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25724157

RESUMEN

Clofarabine, a deoxyadenosine analog, was an active anticancer drug in our in vitro high-throughput screening against mouse ependymoma neurospheres. To characterize the clofarabine disposition in mice for further preclinical efficacy studies, we evaluated the plasma and central nervous system disposition in a mouse model of ependymoma. A plasma pharmacokinetic study of clofarabine (45 mg/kg, IP) was performed in CD1 nude mice bearing ependymoma to obtain initial plasma pharmacokinetic parameters. These estimates were used to derive D-optimal plasma sampling time points for cerebral microdialysis studies. A simulation of clofarabine pharmacokinetics in mice and pediatric patients suggested that a dosage of 30 mg/kg IP in mice would give exposures comparable to that in children at a dosage of 148 mg/m(2). Cerebral microdialysis was performed to study the tumor extracellular fluid (ECF) disposition of clofarabine (30 mg/kg, IP) in the ependymoma cortical allografts. Plasma and tumor ECF concentration-time data were analyzed using a nonlinear mixed effects modeling approach. The median unbound fraction of clofarabine in mouse plasma was 0.79. The unbound tumor to plasma partition coefficient (K pt,uu: ratio of tumor to plasma AUCu,0-inf) of clofarabine was 0.12 ± 0.05. The model-predicted mean tumor ECF clofarabine concentrations were below the in vitro 1-h IC50 (407 ng/mL) for ependymoma neurospheres. Thus, our results show the clofarabine exposure reached in the tumor ECF was below that associated with an antitumor effect in our in vitro washout study. Therefore, clofarabine was de-prioritized as an agent to treat ependymoma, and further preclinical studies were not pursued.


Asunto(s)
Nucleótidos de Adenina/farmacología , Nucleótidos de Adenina/farmacocinética , Arabinonucleósidos/farmacología , Arabinonucleósidos/farmacocinética , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/metabolismo , Ependimoma/tratamiento farmacológico , Ependimoma/metabolismo , Nucleótidos de Adenina/sangre , Adolescente , Animales , Antimetabolitos Antineoplásicos/sangre , Antimetabolitos Antineoplásicos/farmacocinética , Antimetabolitos Antineoplásicos/farmacología , Arabinonucleósidos/sangre , Proteínas Sanguíneas/metabolismo , Encéfalo/metabolismo , Neoplasias Encefálicas/sangre , Niño , Preescolar , Clofarabina , Ependimoma/sangre , Femenino , Humanos , Ratones , Ratones Desnudos , Modelos Biológicos , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto
9.
J Nat Prod ; 77(4): 902-9, 2014 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-24617915

RESUMEN

The generation of natural product libraries containing column fractions, each with only a few small molecules, using a high-throughput, automated fractionation system, has made it possible to implement an improved dereplication strategy for selection and prioritization of leads in a natural product discovery program. Analysis of databased UPLC-MS-ELSD-PDA information of three leads from a biological screen employing the ependymoma cell line EphB2-EPD generated details on the possible structures of active compounds present. The procedure allows the rapid identification of known compounds and guides the isolation of unknown compounds of interest. Three previously known flavanone-type compounds, homoeriodictyol (1), hesperetin (2), and sterubin (3), were identified in a selected fraction derived from the leaves of Eriodictyon angustifolium. The lignan compound deoxypodophyllotoxin (8) was confirmed to be an active constituent in two lead fractions derived from the bark and leaves of Thuja occidentalis. In addition, two new but inactive labdane-type diterpenoids with an uncommon triol side chain were also identified as coexisting with deoxypodophyllotoxin in a lead fraction from the bark of T. occidentalis. Both diterpenoids were isolated in acetylated form, and their structures were determined as 14S,15-diacetoxy-13R-hydroxylabd-8(17)-en-19-oic acid (9) and 14R,15-diacetoxy-13S-hydroxylabd-8(17)-en-19-oic acid (10), respectively, by spectroscopic data interpretation and X-ray crystallography. This work demonstrates that a UPLC-MS-ELSD-PDA database produced during fractionation may be used as a powerful dereplication tool to facilitate compound identification from chromatographically tractable small-molecule natural product libraries.


Asunto(s)
Productos Biológicos/química , Productos Biológicos/aislamiento & purificación , Diterpenos/aislamiento & purificación , Flavonas/aislamiento & purificación , Hesperidina/aislamiento & purificación , Espectrometría de Masas/métodos , Bibliotecas de Moléculas Pequeñas , Thuja/química , Arizona , Técnicas Químicas Combinatorias , Cristalografía por Rayos X , Bases de Datos Factuales , Diterpenos/química , Flavonas/química , Hesperidina/química , Conformación Molecular , Estructura Molecular , Hojas de la Planta/química
10.
J Exp Med ; 211(3): 473-86, 2014 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-24567448

RESUMEN

Pharmacological targeting of metabolic processes in cancer must overcome redundancy in biosynthetic pathways. Deoxycytidine (dC) triphosphate (dCTP) can be produced both by the de novo pathway (DNP) and by the nucleoside salvage pathway (NSP). However, the role of the NSP in dCTP production and DNA synthesis in cancer cells is currently not well understood. We show that acute lymphoblastic leukemia (ALL) cells avoid lethal replication stress after thymidine (dT)-induced inhibition of DNP dCTP synthesis by switching to NSP-mediated dCTP production. The metabolic switch in dCTP production triggered by DNP inhibition is accompanied by NSP up-regulation and can be prevented using DI-39, a new high-affinity small-molecule inhibitor of the NSP rate-limiting enzyme dC kinase (dCK). Positron emission tomography (PET) imaging was useful for following both the duration and degree of dCK inhibition by DI-39 treatment in vivo, thus providing a companion pharmacodynamic biomarker. Pharmacological co-targeting of the DNP with dT and the NSP with DI-39 was efficacious against ALL models in mice, without detectable host toxicity. These findings advance our understanding of nucleotide metabolism in leukemic cells, and identify dCTP biosynthesis as a potential new therapeutic target for metabolic interventions in ALL and possibly other hematological malignancies.


Asunto(s)
Vías Biosintéticas/fisiología , Desoxicitidina Quinasa/antagonistas & inhibidores , Nucleótidos de Desoxicitosina/biosíntesis , Erradicación de la Enfermedad/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Animales , Vías Biosintéticas/efectos de los fármacos , Nucleótidos de Desoxicitosina/metabolismo , Ratones , Tomografía de Emisión de Positrones , Timidina/farmacología
11.
J Biomol Screen ; 19(1): 158-67, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23989453

RESUMEN

Signaling by the BCR-ABL fusion kinase drives Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) and chronic myelogenous leukemia (CML). Despite their clinical activity in many patients with CML, the BCR-ABL kinase inhibitors (BCR-ABL-KIs) imatinib, dasatinib, and nilotinib provide only transient leukemia reduction in patients with Ph+ ALL. While host-derived growth factors in the leukemia microenvironment have been invoked to explain this drug resistance, their relative contribution remains uncertain. Using genetically defined murine Ph+ ALL cells, we identified interleukin 7 (IL-7) as the dominant host factor that attenuates response to BCR-ABL-KIs. To identify potential combination drugs that could overcome this IL-7-dependent BCR-ABL-KI-resistant phenotype, we screened a small-molecule library including Food and Drug Administration-approved drugs. Among the validated hits, the well-tolerated antimalarial drug dihydroartemisinin (DHA) displayed potent activity in vitro and modest in vivo monotherapy activity against engineered murine BCR-ABL-KI-resistant Ph+ ALL. Strikingly, cotreatment with DHA and dasatinib in vivo strongly reduced primary leukemia burden and improved long-term survival in a murine model that faithfully captures the BCR-ABL-KI-resistant phenotype of human Ph+ ALL. This cotreatment protocol durably cured 90% of treated animals, suggesting that this cell-based screening approach efficiently identified drugs that could be rapidly moved to human clinical testing.


Asunto(s)
Antineoplásicos/farmacología , Ensayos de Selección de Medicamentos Antitumorales/métodos , Proteínas de Fusión bcr-abl/antagonistas & inhibidores , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimología , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Inhibidores de Proteínas Quinasas/farmacología , Microambiente Tumoral/efectos de los fármacos , Animales , Citocinas/metabolismo , Descubrimiento de Drogas/métodos , Resistencia a Antineoplásicos/genética , Ensayos Analíticos de Alto Rendimiento , Humanos , Ratones , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/metabolismo , Fenotipo
12.
Cancer Lett ; 328(1): 168-75, 2013 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-22906418

RESUMEN

To better understand neuroblastoma differentiation, we used microarray analysis to identify common gene expression changes from three differentiation models. This revealed STMN4 and ROBO2 to be consistently up-regulated in differentiated neuroblastoma cells induced by chromosome 1 transfer, MYCN knockdown, and 9-cis retinoic acid (9cRA). Furthermore, stable expression of transfected STMN4 or ROBO2 induced differentiation in IMR-32 cells. STMN4 and ROBO2 expression also increased in other 9cRA-induced differentiated neuroblastoma cell lines. Of clinical importance is that neuroblastoma patients with higher tumour mRNA expression of STMN4 and ROBO2 had better progression-free survival. This study highlights the importance of STMN4 and ROBO2 during neuroblastoma differentiation.


Asunto(s)
Diferenciación Celular/genética , Factores de Crecimiento Nervioso/genética , Neuroblastoma/genética , Receptores Inmunológicos/genética , Estatmina/genética , Línea Celular Tumoral , Expresión Génica , Humanos
13.
Cancer Cell ; 20(3): 384-99, 2011 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-21907928

RESUMEN

Using a mouse model of ependymoma-a chemoresistant brain tumor-we combined multicell high-throughput screening (HTS), kinome-wide binding assays, and in vivo efficacy studies, to identify potential treatments with predicted toxicity against neural stem cells (NSC). We identified kinases within the insulin signaling pathway and centrosome cycle as regulators of ependymoma cell proliferation, and their corresponding inhibitors as potential therapies. FDA approved drugs not currently used to treat ependymoma were also identified that posses selective toxicity against ependymoma cells relative to normal NSCs both in vitro and in vivo, e.g., 5-fluorouracil. Our comprehensive approach advances understanding of the biology and treatment of ependymoma including the discovery of several treatment leads for immediate clinical translation.


Asunto(s)
Neoplasias Encefálicas/tratamiento farmacológico , Ensayos de Selección de Medicamentos Antitumorales , Ependimoma/tratamiento farmacológico , Ensayos Analíticos de Alto Rendimiento/métodos , Células-Madre Neurales/efectos de los fármacos , Animales , Ácidos Borónicos/farmacología , Bortezomib , Encéfalo/patología , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Proliferación Celular , Centrosoma/metabolismo , Ependimoma/metabolismo , Ependimoma/patología , Fluorouracilo/farmacología , Insulina/metabolismo , Ratones , Ratones Desnudos , Pirazinas/farmacología , Transducción de Señal , Células Tumorales Cultivadas
14.
Blood ; 117(13): 3585-95, 2011 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-21263154

RESUMEN

The introduction of cultured p185(BCR-ABL)-expressing (p185+) Arf (-/-) pre-B cells into healthy syngeneic mice induces aggressive acute lymphoblastic leukemia (ALL) that genetically and phenotypically mimics the human disease. We adapted this high-throughput Philadelphia chromosome-positive (Ph(+)) ALL animal model for in vivo luminescent imaging to investigate disease progression, targeted therapeutic response, and ALL relapse in living mice. Mice bearing high leukemic burdens (simulating human Ph(+) ALL at diagnosis) entered remission on maximally intensive, twice-daily dasatinib therapy, but invariably relapsed with disseminated and/or central nervous system disease. Although relapse was frequently accompanied by the eventual appearance of leukemic clones harboring BCR-ABL kinase domain (KD) mutations that confer drug resistance, their clonal emergence required prolonged dasatinib exposure. KD P-loop mutations predominated in mice receiving less intensive therapy, whereas high-dose treatment selected for T315I "gatekeeper" mutations resistant to all 3 Food and Drug Administration-approved BCR-ABL kinase inhibitors. The addition of dexamethasone and/or L-asparaginase to reduced-intensity dasatinib therapy improved long-term survival of the majority of mice that received all 3 drugs. Although non-tumor-cell-autonomous mechanisms can prevent full eradication of dasatinib-refractory ALL in this clinically relevant model, the emergence of resistance to BCR-ABL kinase inhibitors can be effectively circumvented by the addition of "conventional" chemotherapeutic agents with alternate antileukemic mechanisms of action.


Asunto(s)
Antineoplásicos/farmacología , Resistencia a Antineoplásicos/efectos de los fármacos , Resistencia a Antineoplásicos/genética , Proteínas de Fusión bcr-abl/genética , Mutagénesis/efectos de los fármacos , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Pirimidinas/uso terapéutico , Tiazoles/uso terapéutico , Animales , Antineoplásicos/uso terapéutico , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Dasatinib , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mutación Missense/efectos de los fármacos , Cromosoma Filadelfia/efectos de los fármacos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Trasplante Isogénico
15.
Drug Metab Dispos ; 39(1): 15-21, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20947617

RESUMEN

Nutlin-3a is an MDM2 inhibitor that is under investigation in preclinical models for a variety of pediatric malignancies, including retinoblastoma, rhabdomyosarcoma, neuroblastoma, and leukemia. We used physiologically based pharmacokinetic (PBPK) modeling to characterize the disposition of nutlin-3a in the mouse. Plasma protein binding and blood partitioning were assessed by in vitro studies. After intravenous (10 and 20 mg/kg) and oral (50, 100, and 200 mg/kg) dosing, tissue concentrations of nutlin-3a were determined in plasma, liver, spleen, intestine, muscle, lung, adipose, bone marrow, adrenal gland, brain, retina, and vitreous fluid. The PBPK model was simultaneously fit to all pharmacokinetic data using NONMEM. Nutlin-3a exhibited nonlinear binding to murine plasma proteins, with the unbound fraction ranging from 0.7 to 11.8%. Nutlin-3a disposition was characterized by rapid absorption with peak plasma concentrations at approximately 2 h and biphasic elimination consistent with a saturable clearance process. The final PBPK model successfully described the plasma and tissue disposition of nutlin-3a. Simulations suggested high bioavailability, rapid attainment of steady state, and little accumulation when administered once or twice daily at dosages up to 400 mg/kg. The final model was used to perform simulations of unbound tissue concentrations to determine which dosing regimens are appropriate for preclinical models of several pediatric malignancies.


Asunto(s)
Imidazoles/administración & dosificación , Imidazoles/farmacocinética , Piperazinas/administración & dosificación , Piperazinas/farmacocinética , Administración Oral , Animales , Disponibilidad Biológica , Proteínas Sanguíneas/metabolismo , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Femenino , Imidazoles/sangre , Imidazoles/farmacología , Inyecciones Intravenosas , Masculino , Ratones , Ratones Endogámicos C57BL , Piperazinas/sangre , Piperazinas/farmacología , Unión Proteica , Proteínas Proto-Oncogénicas c-mdm2/antagonistas & inhibidores , Distribución Tisular
16.
Dev Cell ; 19(1): 138-47, 2010 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-20643356

RESUMEN

The mammalian PCP pathway regulates diverse developmental processes requiring coordinated cellular movement, including neural tube closure and cochlear stereociliary orientation. Here, we show that epidermal wound repair is regulated by PCP signaling. Mice carrying mutant alleles of PCP genes Vangl2, Celsr1, PTK7, and Scrb1, and the transcription factor Grhl3, interact genetically, exhibiting failed wound healing, neural tube defects, and disordered cochlear polarity. Using phylogenetic analysis, ChIP, and gene expression in Grhl3(-)(/-) mice, we identified RhoGEF19, a homolog of a RhoA activator involved in PCP signaling in Xenopus, as a direct target of GRHL3. Knockdown of Grhl3 or RhoGEF19 in keratinocytes induced defects in actin polymerization, cellular polarity, and wound healing, and re-expression of RhoGEF19 rescued these defects in Grhl3-kd cells. These results define a role for Grhl3 in PCP signaling and broadly implicate this pathway in epidermal repair.


Asunto(s)
Polaridad Celular/fisiología , Epidermis/lesiones , Epidermis/fisiología , Cicatrización de Heridas/fisiología , Actinas/metabolismo , Animales , Proteínas de Unión al ADN/deficiencia , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/fisiología , Epidermis/embriología , Femenino , Factores de Intercambio de Guanina Nucleótido/deficiencia , Factores de Intercambio de Guanina Nucleótido/genética , Factores de Intercambio de Guanina Nucleótido/fisiología , Queratinocitos/citología , Queratinocitos/fisiología , Ratones , Ratones Noqueados , Ratones Mutantes , Modelos Biológicos , Mutación , Proteínas del Tejido Nervioso/deficiencia , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/fisiología , Embarazo , Factores de Intercambio de Guanina Nucleótido Rho , Transducción de Señal , Factores de Transcripción/deficiencia , Factores de Transcripción/genética , Factores de Transcripción/fisiología , Cicatrización de Heridas/genética
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