RESUMEN
Interleukin-7 (IL-7) supports the growth and chemoresistance of T-cell acute lymphoblastic leukemia (T-ALL), particularly the early T-cell precursor subtype (ETP-ALL), which frequently has activating mutations of IL-7 signaling. Signal transducer and activator of transcription (STAT5) is an attractive therapeutic target because it is almost universally activated in ETP-ALL, even in the absence of mutations of upstream activators such as the IL-7 receptor (IL-7R), Janus kinase, and Fms-like tyrosine kinase 3 (FLT3). To examine the role of activated STAT5 in ETP-ALL, we have used a Lmo2-transgenic (Lmo2Tg) mouse model in which we can monitor chemoresistant preleukemia stem cells (pre-LSCs) and leukemia stem cells (LSCs) that drive T-ALL development and relapse following chemotherapy. Using IL-7R-deficient Lmo2Tg mice, we show that IL-7 signaling was not required for the formation of pre-LSCs but essential for their expansion and clonal evolution into LSCs to generate T-ALL. Activated STAT5B was sufficient for the development of T-ALL in IL-7R-deficient Lmo2Tg mice, indicating that inhibition of STAT5 is required to block the supportive signals provided by IL-7. To further understand the role of activated STAT5 in LSCs of ETP-ALL, we developed a new transgenic mouse that enables T-cell specific and doxycycline-inducible expression of the constitutively activated STAT5B1∗6 mutant. Expression of STAT5B1∗6 in T cells had no effect alone but promoted expansion and chemoresistance of LSCs in Lmo2Tg mice. Pharmacologic inhibition of STAT5 with pimozide-induced differentiation and loss of LSCs, while enhancing response to chemotherapy. Furthermore, pimozide significantly reduced leukemia burden in vivo and overcame chemoresistance of patient-derived ETP-ALL xenografts. Overall, our results demonstrate that STAT5 is an attractive therapeutic target for eradicating LSCs in ETP-ALL.
Asunto(s)
Células Precursoras de Linfocitos T , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Humanos , Ratones , Animales , Factor de Transcripción STAT5/genética , Factor de Transcripción STAT5/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Interleucina-7/genética , Interleucina-7/metabolismo , Pimozida/uso terapéutico , Ratones TransgénicosRESUMEN
ETV6::ACSL6 represents a rare genetic aberration in hematopoietic neoplasms and is often associated with severe eosinophilia, which confers an unfavorable prognosis requiring additional anti-inflammatory treatment. However, since the translocation is unlikely to produce a fusion protein, the mechanism of ETV6::ACSL6 action remains unclear. Here, we performed multi-omics analyses of primary leukemia cells and patient-derived xenografts from an acute lymphoblastic leukemia (ALL) patient with ETV6::ACSL6 translocation. We identified a super-enhancer located within the ETV6 gene locus, and revealed translocation and activation of the super-enhancer associated with the ETV6::ACSL6 fusion. The translocated super-enhancer exhibited intense interactions with genomic regions adjacent to and distal from the breakpoint at chromosomes 5 and 12, including genes coding inflammatory factors such as IL-3. This led to modulations in DNA methylation, histone modifications, and chromatin structures, triggering transcription of inflammatory factors leading to eosinophilia. Furthermore, the bromodomain and extraterminal domain (BET) inhibitor synergized with standard-of-care drugs for ALL, effectively reducing IL-3 expression and inhibiting ETV6::ACSL6 ALL growth in vitro and in vivo. Overall, our study revealed for the first time a cis-regulatory mechanism of super-enhancer translocation in ETV6::ACSL6ALL, leading to an ALL-accompanying clinical syndrome. These findings may stimulate novel treatment approaches for this challenging ALL subtype.
Asunto(s)
Proteína ETS de Variante de Translocación 6 , Elementos de Facilitación Genéticos , Eosinofilia , Interleucina-3 , Proteínas de Fusión Oncogénica , Leucemia-Linfoma Linfoblástico de Células Precursoras , Proteínas Proto-Oncogénicas c-ets , Proteínas Represoras , Translocación Genética , Animales , Humanos , Ratones , Eosinofilia/genética , Eosinofilia/metabolismo , Eosinofilia/patología , Regulación Leucémica de la Expresión Génica , Interleucina-3/genética , Interleucina-3/metabolismo , Proteínas de Fusión Oncogénica/genética , Proteínas de Fusión Oncogénica/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Proteínas Proto-Oncogénicas c-ets/genética , Proteínas Proto-Oncogénicas c-ets/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/metabolismoRESUMEN
BACKGROUND: Acute lymphoblastic leukemia (ALL) remains one of the most common causes of cancer-related mortality in children. Phosphoinositide 3-kinases (PI3Ks) are a family of lipid kinases, and aberrations in the PI3K pathway are associated with several hematological malignancies, including ALL. Duvelisib (Copiktra) is an orally available, small molecule dual inhibitor of PI3Kδ and PI3Kγ, that is Food and Drug Administration (FDA) approved for the treatment of relapsed/refractory chronic lymphocytic leukemia and small lymphocytic lymphoma. Here, we report the efficacy of duvelisib against a panel of pediatric ALL patient-derived xenografts (PDXs). PROCEDURES: Thirty PDXs were selected for a single mouse trial based on PI3Kδ (PIK3CD) and PI3Kγ (PIK3CG) expression and mutational status. PDXs were grown orthotopically in NSG (NOD.Cg-Prkdcscid IL2rgtm1Wjl /SzJAusb) mice, and engraftment was evaluated by enumerating the proportion of human versus mouse CD45+ cells (%huCD45+ ) in the peripheral blood. Treatment commenced when the %huCD45+ reached greater than or equal to 1%, and events were predefined as %huCD45+ greater than or equal to 25% or leukemia-related morbidity. Duvelisib was administered per oral (50 mg/kg, twice daily for 28 days). Drug efficacy was assessed by event-free survival and stringent objective response measures. RESULTS: PI3Kδ and PI3Kγ mRNA expression was significantly higher in B-lineage than T-lineage ALL PDXs (p-values <.0001). Duvelisib was well-tolerated and reduced leukemia cells in the peripheral blood in four PDXs, but with only one objective response. There was no obvious relationship between duvelisib efficacy and PI3Kδ or PI3Kγ expression or mutation status, nor was the in vivo response to duvelisib subtype dependent. CONCLUSIONS: Duvelisib demonstrated limited in vivo activity against ALL PDXs.
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Leucemia Linfocítica Crónica de Células B , Linfoma de Células B , Leucemia-Linfoma Linfoblástico de Células Precursoras , Niño , Humanos , Animales , Ratones , Xenoinjertos , Fosfatidilinositol 3-Quinasas , Ratones Endogámicos NOD , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Linfoma de Células B/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológicoRESUMEN
BACKGROUND: While children with acute lymphoblastic leukemia (ALL) experience close to a 90% likelihood of cure, the outcome for certain high-risk pediatric ALL subtypes remains dismal. Spleen tyrosine kinase (SYK) is a prominent cytosolic nonreceptor tyrosine kinase in pediatric B-lineage ALL (B-ALL). Activating mutations or overexpression of Fms-related receptor tyrosine kinase 3 (FLT3) are associated with poor outcome in hematological malignancies. TAK-659 (mivavotinib) is a dual SYK/FLT3 reversible inhibitor, which has been clinically evaluated in several other hematological malignancies. Here, we investigate the in vivo efficacy of TAK-659 against pediatric ALL patient-derived xenografts (PDXs). METHODS: SYK and FLT3 mRNA expression was quantified by RNA-seq. PDX engraftment and drug responses in NSG mice were evaluated by enumerating the proportion of human CD45+ cells (%huCD45+ ) in the peripheral blood. TAK-659 was administered per oral at 60 mg/kg daily for 21 days. Events were defined as %huCD45+ ≥ 25%. In addition, mice were humanely killed to assess leukemia infiltration in the spleen and bone marrow (BM). Drug efficacy was assessed by event-free survival and stringent objective response measures. RESULTS: FLT3 and SYK mRNA expression was significantly higher in B-lineage compared with T-lineage PDXs. TAK-659 was well tolerated and significantly prolonged the time to event in six out of eight PDXs tested. However, only one PDX achieved an objective response. The minimum mean %huCD45+ was significantly reduced in five out of eight PDXs in TAK-659-treated mice compared with vehicle controls. CONCLUSIONS: TAK-659 exhibited low to moderate single-agent in vivo activity against pediatric ALL PDXs representative of diverse subtypes.
RESUMEN
BACKGROUND: The prognosis for high-risk childhood acute leukaemias remains dismal and established treatment protocols often cause long-term side effects in survivors. This study aims to identify more effective and safer therapeutics for these patients. METHODS: A high-throughput phenotypic screen of a library of 3707 approved drugs and pharmacologically active compounds was performed to identify compounds with selective cytotoxicity against leukaemia cells followed by further preclinical evaluation in patient-derived xenograft models. RESULTS: Auranofin, an FDA-approved agent for the treatment of rheumatoid arthritis, was identified as exerting selective anti-cancer activity against leukaemia cells, including patient-derived xenograft cells from children with high-risk ALL, versus solid tumour and non-cancerous cells. It induced apoptosis in leukaemia cells by increasing reactive oxygen species (ROS) and potentiated the activity of the chemotherapeutic cytarabine against highly aggressive models of infant MLL-rearranged ALL by enhancing DNA damage accumulation. The enhanced sensitivity of leukaemia cells towards auranofin was associated with lower basal levels of the antioxidant glutathione and higher baseline ROS levels compared to solid tumour cells. CONCLUSIONS: Our study highlights auranofin as a well-tolerated drug candidate for high-risk paediatric leukaemias that warrants further preclinical investigation for application in high-risk paediatric and adult acute leukaemias.
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Auranofina/administración & dosificación , Citarabina/administración & dosificación , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Especies Reactivas de Oxígeno/metabolismo , Animales , Auranofina/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Niño , Citarabina/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Sinergismo Farmacológico , Femenino , Ensayos Analíticos de Alto Rendimiento , Humanos , Ratones , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Bibliotecas de Moléculas Pequeñas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Around 10% of acute leukemias harbor a rearrangement of the MLL/KMT2A gene, and the presence of this translocation results in a highly aggressive, therapy-resistant leukemia subtype with survival rates below 50%. There is a high unmet need to identify safer and more potent therapies for MLL-rearranged (MLL-r) leukemia that can be combined with established chemotherapeutics to decrease treatment-related toxicities. The curaxin, CBL0137, has demonstrated nongenotoxic anticancer and chemopotentiating effects in a number of preclinical cancer models and is currently in adult Phase I clinical trials for solid tumors and hematological malignancies. The aim of our study was to investigate whether CBL0137 has potential as a therapeutic and chemopotentiating compound in MLL-r leukemia through a comprehensive analysis of its efficacy in preclinical models of the disease. CBL0137 decreased the viability of a panel of MLL-r leukemia cell lines (n = 12) and xenograft cells derived from patients with MLL-r acute lymphoblastic leukemia (ALL, n = 3) in vitro with submicromolar IC50s. The small molecule drug was well-tolerated in vivo and significantly reduced leukemia burden in a subcutaneous MV4;11 MLL-r acute myeloid leukemia model and in patient-derived xenograft models of MLL-r ALL (n = 5). The in vivo efficacy of standard of care drugs used in remission induction for pediatric ALL was also potentiated by CBL0137. CBL0137 exerted its anticancer effect by trapping Facilitator of Chromatin Transcription (FACT) into chromatin, activating the p53 pathway and inducing an Interferon response. Our findings support further preclinical evaluation of CBL0137 as a new approach for the treatment of MLL-r leukemia.
Asunto(s)
Antineoplásicos/farmacología , Carbazoles/farmacología , Reordenamiento Génico , N-Metiltransferasa de Histona-Lisina/genética , Proteína de la Leucemia Mieloide-Linfoide/genética , Animales , Antineoplásicos/uso terapéutico , Apoptosis/genética , Carbazoles/uso terapéutico , Línea Celular Tumoral , Proteínas de Unión al ADN/genética , Modelos Animales de Enfermedad , Perfilación de la Expresión Génica , Proteínas del Grupo de Alta Movilidad/genética , Humanos , Estimación de Kaplan-Meier , Leucemia Bifenotípica Aguda/diagnóstico , Leucemia Bifenotípica Aguda/tratamiento farmacológico , Leucemia Bifenotípica Aguda/genética , Leucemia Bifenotípica Aguda/mortalidad , Ratones , Transducción de Señal/efectos de los fármacos , Factores de Elongación Transcripcional/genética , Transcriptoma , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: Acute lymphoblastic leukaemia (ALL) is the most common paediatric malignancy. Glucocorticoids form a critical component of chemotherapy regimens and resistance to glucocorticoid therapy is predictive of poor outcome. We have previously shown that glucocorticoid resistance is associated with upregulation of the oncogene C-MYC and failure to induce the proapoptotic gene BIM. METHODS: A high-throughput screening (HTS) campaign was carried out to identify glucocorticoid sensitisers against an ALL xenograft derived from a glucocorticoid-resistant paediatric patient. Gene expression analysis was carried out using Illumina microarrays. Efficacy, messenger RNA and protein analysis were carried out by Resazurin assay, reverse transcription-PCR and immunoblotting, respectively. RESULTS: A novel glucocorticoid sensitiser, 2-((4,5-dihydro-1H-imidazol-2-yl)thio)-N-isopropyl-N-phenylacetamide (GCS-3), was identified from the HTS campaign. The sensitising effect was specific to glucocorticoids and synergy was observed in a range of dexamethasone-resistant and dexamethasone-sensitive xenografts representative of B-ALL, T-ALL and Philadelphia chromosome-positive ALL. GCS-3 in combination with dexamethasone downregulated C-MYC and significantly upregulated BIM expression in a glucocorticoid-resistant ALL xenograft. The GCS-3/dexamethasone combination significantly increased binding of the glucocorticoid receptor to a novel BIM enhancer, which is associated with glucocorticoid sensitivity. CONCLUSIONS: This study describes the potential of the novel glucocorticoid sensitiser, GCS-3, as a biological tool to interrogate glucocorticoid action and resistance.
Asunto(s)
Antineoplásicos/farmacología , Proteína 11 Similar a Bcl2/metabolismo , Resistencia a Antineoplásicos/efectos de los fármacos , Resistencia a Antineoplásicos/fisiología , Leucemia-Linfoma Linfoblástico de Células Precursoras , Animales , Dexametasona/farmacología , Descubrimiento de Drogas/métodos , Glucocorticoides/farmacología , Humanos , Receptores de Glucocorticoides/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: While current chemotherapy has increased cure rates for children with acute lymphoblastic leukaemia (ALL), the largest number of relapsing patients are still stratified as medium risk (MR) at diagnosis (50-60%). This highlights an opportunity to develop improved relapse-prediction models for MR patients. We hypothesised that bone marrow from MR patients who eventually relapsed would regrow faster in a patient-derived xenograft (PDX) model after induction chemotherapy than samples from patients in long-term remission. METHODS: Diagnostic bone marrow aspirates from 30 paediatric MR-ALL patients (19 who relapsed, 11 who experienced remission) were inoculated into immune-deficient (NSG) mice and subsequently treated with either control or an induction-type regimen of vincristine, dexamethasone, and L-asparaginase (VXL). Engraftment was monitored by enumeration of the proportion of human CD45+ cells (%huCD45+) in the murine peripheral blood, and events were defined a priori as the time to reach 1% huCD45+, 25% huCD45+ (TT25%) or clinical manifestations of leukaemia (TTL). RESULTS: The TT25% value significantly predicted MR patient relapse. Mutational profiles of PDXs matched their tumours of origin, with a clonal shift towards relapse observed in one set of VXL-treated PDXs. CONCLUSIONS: In conclusion, establishing PDXs at diagnosis and subsequently applying chemotherapy has the potential to improve relapse prediction in paediatric MR-ALL.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Médula Ósea/efectos de los fármacos , Médula Ósea/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Adolescente , Animales , Asparaginasa/administración & dosificación , Niño , Preescolar , Dexametasona/administración & dosificación , Femenino , Xenoinjertos/efectos de los fármacos , Humanos , Masculino , Ratones , Ratones Endogámicos NOD , Ratones SCID , Valor Predictivo de las Pruebas , Recurrencia , Vincristina/administración & dosificaciónRESUMEN
BACKGROUND: The aim of this study was to improve the predictive power of patient-derived xenografts (PDXs, also known as mouse avatars) to more accurately reflect outcomes of clofarabine-based treatment in pediatric acute lymphoblastic leukemia (ALL) patients. PROCEDURE: Pharmacokinetic (PK) studies were conducted using clofarabine at 3.5 to 15 mg/kg in mice. PDXs were established from relapsed/refractory ALL patients who exhibited good or poor responses to clofarabine. PDX engraftment and response to clofarabine (either as a single agent or in combinations) were assessed based on stringent objective response measures modeled after the clinical setting. RESULTS: In naïve immune-deficient NSG mice, we determined that a clofarabine dose of 3.5 mg/kg resulted in systemic exposures equivalent to those achieved in pediatric ALL patients treated with clofarabine-based regimens. This dose was markedly lower than the doses of clofarabine used in previously reported preclinical studies (typically 30-60 mg/kg) and, when scheduled consistent with the clinical regimen (daily × 5), resulted in 34-fold lower clofarabine exposures. Using a well-tolerated clofarabine/etoposide/cyclophosphamide combination regimen, we then found that the responses of PDXs better reflected the clinical responses of the patients from whom the PDXs were derived. CONCLUSIONS: This study has identified an in vivo clofarabine treatment regimen that reflects the clinical responses of relapsed/refractory pediatric ALL patients. This regimen could be used prospectively to identify patients who might benefit from clofarabine-based treatment. Our findings are an important step toward individualizing prospective patient selection for the use of clofarabine in relapsed/refractory pediatric ALL patients and highlight the need for detailed PK evaluation in murine PDX models.
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Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Medicina de Precisión/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Ensayos Antitumor por Modelo de Xenoinjerto , Animales , Antimetabolitos Antineoplásicos/farmacología , Clofarabina/farmacología , Ciclofosfamida/farmacología , Etopósido/farmacología , Humanos , RatonesRESUMEN
After a novel human coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was reported in China in December 2019, the disease quickly reached pandemic level. On January 30, 2020, the World Health Organization (WHO) declared that the SARS-CoV-2 outbreak constituted a Public Health Emergency of International Concern. The caseload has increased exponentially, with WHO reporting 182 000 global cases by March 17, 2020, and over 2.6 million by 23 April. The clinical situation is complex, with children presenting different clinical features compared to adults. Several articles with recommendations on the anesthetic management of adult patients with COVID-19 have been published, but no specific recommendations for pediatric anesthesiologists have been made yet. This article addresses specific concerns for the anesthetic management of the pediatric population with COVID-19.
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Anestesia/normas , Anestésicos/uso terapéutico , Infecciones por Coronavirus/epidemiología , Pediatría/normas , Neumonía Viral/epidemiología , Anestesia/métodos , COVID-19 , Niño , China/epidemiología , Brotes de Enfermedades , Humanos , Pandemias , Pediatría/métodos , Guías de Práctica Clínica como AsuntoRESUMEN
BACKGROUND: Denintuzumab mafodotin (SGN-CD19A) is a CD19-targeting antibody-drug conjugate, comprising a monoclonal antibody conjugated to the potent cytotoxin monomethyl auristatin F. Since denintuzumab mafodotin has previously shown activity against B-cell malignancies in early-stage clinical trials, it was of interest to test it against the Pediatric Preclinical Testing Program preclinical models of CD19+ pediatric acute lymphoblastic leukemia (ALL). PROCEDURES: Denintuzumab mafodotin was evaluated against eight B-cell lineage ALL patient-derived xenografts (PDXs), representing B-cell precursor ALL, Ph-like ALL, and mixed-lineage leukemia rearranged infant ALL. Denintuzumab mafodotin was administered weekly for 3 weeks at 3 mg/kg. It was also tested in combination with an induction-type chemotherapy regimen of vincristine, dexamethasone, and l-asparaginase (VXL) against three PDXs. The relationship between cell surface and gene expression of CD19 and drug activity was also assessed. RESULTS: Denintuzumab mafodotin significantly delayed the progression of seven of eight PDXs tested and achieved objective responses in five of eight. There was no apparent subtype specificity of denintuzumab mafodotin activity. No correlations were observed between CD19 mRNA or cell surface expression and denintuzumab mafodotin activity, perhaps due to small sample size, and denintuzumab mafodotin treatment did not select for reduced CD19 expression. Combining denintuzumab mafodotin with VXL achieved therapeutic enhancement compared to either treatment alone. CONCLUSIONS: Denintuzumab mafodotin showed single-agent activity against selected B-lineage ALL PDXs, although leukemia growth was evident in most models at 28 days from treatment initiation. This level of activity for denintuzumab mafodotin is consistent with that observed in adults with ALL.
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Anticuerpos Monoclonales Humanizados/administración & dosificación , Antígenos CD19/inmunología , Inmunoconjugados/administración & dosificación , Oligopéptidos/administración & dosificación , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Adolescente , Animales , Antígenos CD19/metabolismo , Niño , Preescolar , Evaluación Preclínica de Medicamentos , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Ratones Endogámicos NOD , Ratones SCID , Leucemia-Linfoma Linfoblástico de Células Precursoras/inmunología , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: Zinc-finger protein 384 (ZNF384) fusions are an emerging subtype of precursor B-cell acute lymphoblastic leukaemia (pre-B-ALL) and here we further characterised their prevalence, survival outcomes and transcriptome. METHODS: Bone marrow mononuclear cells from 274 BCR-ABL1-negative pre-B-ALL patients were immunophenotyped and transcriptome molecularly characterised. Transcriptomic data was analysed by principal component analysis and gene-set enrichment analysis to identify gene and pathway expression changes. RESULTS: We exclusively detect E1A-associated protein p300 (EP300)-ZNF384 in 5.7% of BCR-ABL1-negative adolescent/young adult (AYA)/adult pre-B-ALL patients. EP300-ZNF384 patients do not appear to be a high-risk subgroup. Transcriptomic analysis revealed that EP300-ZNF384 samples have a distinct gene expression profile that results in the up-regulation of Janus kinase/signal transducers and activators of transcription (JAK/STAT) and cell adhesion pathways and down-regulation of cell cycle and DNA repair pathways. CONCLUSIONS: Importantly, this report contributes to a better overview of the incidence of EP300-ZNF384 patients and show that they have a distinct gene signature with concurrent up-regulation of JAK-STAT pathway, reduced expression of B-cell regulators and reduced DNA repair capacity.
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Proteína p300 Asociada a E1A/genética , Proteínas de Fusión Oncogénica/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiología , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Transactivadores/genética , Transcriptoma , Adolescente , Adulto , Niño , Femenino , Perfilación de la Expresión Génica , Regulación Leucémica de la Expresión Génica , Frecuencia de los Genes , Genes abl/genética , Humanos , Quinasas Janus/metabolismo , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidad , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Recurrencia , Factores de Transcripción STAT/metabolismo , Transducción de Señal/genética , Análisis de Supervivencia , Adulto JovenRESUMEN
The clinical success of the BCL-2-selective BH3-mimetic venetoclax in patients with poor prognosis chronic lymphocytic leukemia (CLL) highlights the potential of targeting the BCL-2-regulated apoptotic pathway in previously untreatable lymphoid malignancies. By selectively inhibiting BCL-2, venetoclax circumvents the dose-limiting, BCL-XL-mediated thrombocytopenia of its less selective predecessor navitoclax, while enhancing efficacy in CLL. We have previously reported the potent sensitivity of many high-risk childhood acute lymphoblastic leukemia (ALL) xenografts to navitoclax. Given the superior tolerability of venetoclax, here we have investigated its efficacy in childhood ALL. We demonstrate that in contrast to the clear dependence of CLL on BCL-2 alone, effective antileukemic activity in the majority of ALL xenografts requires concurrent inhibition of both BCL-2 and BCL-XL We identify BCL-XL expression as a key predictor of poor response to venetoclax and demonstrate that concurrent inhibition of both BCL-2 and BCL-XL results in synergistic killing in the majority of ALL xenografts. A notable exception is mixed lineage leukemia-rearranged infant ALL, where venetoclax largely recapitulates the activity of navitoclax, identifying this subgroup of patients as potential candidates for clinical trials of venetoclax in childhood ALL. Conversely, our findings provide a clear basis for progressing navitoclax into trials ahead of venetoclax in other subgroups.
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Antineoplásicos/uso terapéutico , Apoptosis/efectos de los fármacos , Compuestos Bicíclicos Heterocíclicos con Puentes/uso terapéutico , Resistencia a Antineoplásicos/efectos de los fármacos , Reordenamiento Génico/genética , N-Metiltransferasa de Histona-Lisina/genética , Proteína de la Leucemia Mieloide-Linfoide/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Sulfonamidas/uso terapéutico , Animales , Apoptosis/genética , Western Blotting , Proliferación Celular/efectos de los fármacos , Niño , Resistencia a Antineoplásicos/genética , Femenino , Citometría de Flujo , Humanos , Ratones , Ratones Endogámicos NOD , Ratones SCID , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Glucocorticoids are critical components of combination chemotherapy regimens in pediatric acute lymphoblastic leukemia (ALL). The proapoptotic BIM protein is an important mediator of glucocorticoid-induced apoptosis in normal and malignant lymphocytes, whereas the antiapoptotic BCL2 confers resistance. The signaling pathways regulating BIM and BCL2 expression in glucocorticoid-treated lymphoid cells remain unclear. In this study, pediatric ALL patient-derived xenografts (PDXs) inherently sensitive or resistant to glucocorticoids were exposed to dexamethasone in vivo. Microarray analysis showed that KLF13 and MYB gene expression changes were significantly greater in dexamethasone-sensitive than -resistant PDXs. Chromatin immunoprecipitation (ChIP) analysis detected glucocorticoid receptor (GR) binding at the KLF13 promoter to trigger KLF13 expression only in sensitive PDXs. Next, KLF13 bound to the MYB promoter, deactivating MYB expression only in sensitive PDXs. Sustained MYB expression in resistant PDXs resulted in maintenance of BCL2 expression and inhibition of apoptosis. ChIP sequencing analysis revealed a novel GR binding site in a BIM intronic region (IGR) that was engaged only in dexamethasone-sensitive PDXs. The absence of GR binding at the BIM IGR was associated with BIM silencing and dexamethasone resistance. This study has identified novel mechanisms of opposing BCL2 and BIM gene regulation that control glucocorticoid-induced apoptosis in pediatric ALL cells in vivo.
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Proteínas Reguladoras de la Apoptosis/genética , Apoptosis/genética , Proteínas de la Membrana/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas/genética , Receptores de Glucocorticoides/genética , Animales , Antineoplásicos Hormonales/farmacología , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Proteínas Reguladoras de la Apoptosis/biosíntesis , Proteína 11 Similar a Bcl2 , Western Blotting , Inmunoprecipitación de Cromatina , Dexametasona/farmacología , Resistencia a Antineoplásicos/genética , Ensayo de Inmunoadsorción Enzimática , Regulación Neoplásica de la Expresión Génica/fisiología , Humanos , Proteínas de la Membrana/biosíntesis , Ratones , Ratones Endogámicos NOD , Ratones SCID , Análisis de Secuencia por Matrices de Oligonucleótidos , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Proteínas Proto-Oncogénicas/biosíntesis , Proteínas Proto-Oncogénicas c-bcl-2/biosíntesis , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores de Glucocorticoides/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal/efectos de los fármacos , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
PR-104, a phosphate ester of the nitrogen mustard prodrug PR-104A, has shown evidence of efficacy in adult leukemia clinical trials. Originally designed to target hypoxic cells, PR-104A is independently activated by aldo-keto-reductase 1C3 (AKR1C3). The aim of this study was to test whether AKR1C3 is a predictive biomarker of in vivo PR-104 sensitivity. In a panel of 7 patient-derived pediatric acute lymphoblastic leukemia (ALL) xenografts, PR-104 showed significantly greater efficacy against T-lineage ALL (T-ALL) than B-cell-precursor ALL (BCP-ALL) xenografts. Single-agent PR-104 was more efficacious against T-ALL xenografts compared with a combination regimen of vincristine, dexamethasone, and l-asparaginase. Expression of AKR1C3 was significantly higher in T-ALL xenografts compared with BCP-ALL, and correlated with PR-104/PR-104A sensitivity in vivo and in vitro. Overexpression of AKR1C3 in a resistant BCP-ALL xenograft resulted in dramatic sensitization to PR-104 in vivo. Testing leukemic blasts from 11 patients confirmed that T-ALL cells were more sensitive than BCP-ALL to PR-104A in vitro, and that sensitivity correlated with AKR1C3 expression. Collectively, these results indicate that PR-104 shows promise as a novel therapy for relapsed/refractory T-ALL, and that AKR1C3 expression could be used as a biomarker to select patients most likely to benefit from such treatment in prospective clinical trials.
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3-Hidroxiesteroide Deshidrogenasas/biosíntesis , Antineoplásicos/farmacología , Biomarcadores de Tumor/análisis , Hidroxiprostaglandina Deshidrogenasas/biosíntesis , Compuestos de Mostaza Nitrogenada/farmacología , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patología , Adolescente , Miembro C3 de la Familia 1 de las Aldo-Ceto Reductasas , Animales , Supervivencia Celular/efectos de los fármacos , Niño , Preescolar , Femenino , Humanos , Immunoblotting , Masculino , Ratones , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Early T-cell precursor (ETP) acute lymphoblastic leukemia (ALL) is a recently described subtype of T-ALL characterized by a unique immunophenotype and genomic profile, as well as a high rate of induction failure. Frequent mutations in cytokine receptor and Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathways led us to hypothesize that ETP-ALL is dependent on JAK/STAT signaling. Here we demonstrate aberrant activation of the JAK/STAT pathway in ETP-ALL blasts relative to non-ETP T-ALL. Moreover, ETP-ALL showed hyperactivation of STAT5 in response to interleukin-7, an effect that was abrogated by the JAK1/2 inhibitor ruxolitinib. In vivo, ruxolitinib displayed activity in 6 of 6 patient-derived murine xenograft models of ETP-ALL, with profound single-agent efficacy in 5 models. Ruxolitinib treatment decreased peripheral blast counts relative to pretreatment levels and compared with control (P < .01) in 5 of 6 ETP-ALL xenografts, with marked reduction in mean splenic blast counts (P < .01) in 6 of 6 samples. Surprisingly, both JAK/STAT pathway activation and ruxolitinib efficacy were independent of the presence of JAK/STAT pathway mutations, raising the possibility that the therapeutic potential of ruxolitinib in ETP-ALL extends beyond those cases with JAK mutations. These findings establish the preclinical in vivo efficacy of ruxolitinib in ETP-ALL, a biologically distinct subtype for which novel therapies are needed.
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Quinasas Janus/antagonistas & inhibidores , Células Precursoras de Linfocitos T/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Factores de Transcripción STAT/antagonistas & inhibidores , Adolescente , Animales , Niño , Preescolar , Femenino , Humanos , Interleucina-7/metabolismo , Quinasas Janus/genética , Masculino , Ratones , Ratones Endogámicos NOD , Ratones SCID , Mutación , Nitrilos , Células Precursoras de Linfocitos T/efectos de los fármacos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Pirazoles/farmacología , Pirimidinas , Factores de Transcripción STAT/genética , Transducción de Señal/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto , Adulto JovenRESUMEN
BACKGROUND: CBL0137 is a novel drug that modulates FAcilitates Chromatin Transcription (FACT), resulting in simultaneous nuclear factor-κB suppression, heat shock factor 1 suppression and p53 activation. CBL0137 has demonstrated antitumor effects in animal models of several adult cancers and neuroblastoma. PROCEDURES: CBL0137 was tested against the Pediatric Preclinical Testing Program (PPTP) in vitro cell line panel at concentrations ranging from 1.0 nM to 10.0 µM and against the PPTP in vivo solid tumor xenograft and acute lymphocytic leukemia (ALL) panels at 50 mg/kg administered intravenously weekly for 4 weeks. RESULTS: The median relative IC50 (rIC50 ) value for the PPTP cell lines was 0.28 µM (range: 0.13-0.80 µM). There were no significant differences in rIC50 values by histotype. CBL0137 induced significant differences in event-free survival (EFS) distribution compared to control in 10 of 31 (32%) evaluable solid tumor xenografts and in eight of eight (100%) evaluable ALL xenografts. Significance differences in EFS distribution were observed in four of six osteosarcoma lines, three of three rhabdoid tumor lines and two of six rhabdomyosarcoma lines. No objective responses were observed among the solid tumor xenografts. For the ALL panel, one xenograft achieved complete response and four achieved partial response. CONCLUSIONS: The most consistent in vivo activity for CBL0137 was observed against ALL xenografts, with some solid tumor xenograft lines showing tumor growth delay. It will be important to relate the drug levels in mice at 50 mg/kg to those in humans at the recommended phase 2 dose.
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Apoptosis/efectos de los fármacos , Carbazoles/farmacología , Proliferación Celular/efectos de los fármacos , Neoplasias Experimentales/tratamiento farmacológico , Adulto , Animales , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones SCID , Neoplasias Experimentales/metabolismo , Neoplasias Experimentales/patología , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
VS-4718, a novel inhibitor of focal adhesion kinase (FAK), was tested against the Pediatric Preclinical Testing Program's (PPTP's) in vitro cell line panel and showed a median relative IC50 of 1.22 µM. VS-4718 was tested in vivo against the PPTP xenograft models using a dose of 50 mg/kg administered by the oral route twice daily for 21 days. VS-4718 induced significant differences in an event-free survival distribution compared with control in 18 of 36 of the evaluable solid tumor xenografts and in 0 of 8 acute lymphoblastic leukemia (ALL) xenografts, but no xenograft lines showed tumor regression. Future plans include further evaluation of the role of FAK inhibition in combination with ABL kinase inhibitors for Ph+ ALL.
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Aminopiridinas/farmacología , Antineoplásicos/farmacología , Proliferación Celular/efectos de los fármacos , Proteína-Tirosina Quinasas de Adhesión Focal/antagonistas & inhibidores , Neoplasias Experimentales/tratamiento farmacológico , Animales , Apoptosis/efectos de los fármacos , Evaluación Preclínica de Medicamentos , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Ratones SCID , Neoplasias Experimentales/patología , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: Selinexor (KPT-330) is an inhibitor of the major nuclear export receptor, exportin 1 (XPO1, also termed chromosome region maintenance 1, CRM1) that has demonstrated activity in preclinical models and clinical activity against several solid and hematological cancers. PROCEDURES: Selinexor was tested against the Pediatric Preclinical Testing Program (PPTP) in vitro cell line panel at concentrations from 1.0 nM to 10 µM and against the PPTP in vivo xenograft panels administered orally at a dose of 10 mg/kg thrice weekly for 4 weeks. RESULTS: Selinexor demonstrated cytotoxic activity in vitro, with a median relative IC50 value of 123 nM (range 13.0 nM to >10 µM). Selinexor induced significant differences in event-free survival (EFS) distribution in 29 of 38 (76%) of the evaluable solid tumor xenografts and in five of eight (63%) of the evaluable ALL xenografts. Objective responses (partial or complete responses, PR/CR) were observed for 4 of 38 solid tumor xenografts including Wilms tumor, medulloblastoma (n = 2), and ependymoma models. For the ALL panel, two of eight (25%) xenografts achieved either CR or maintained CR. Two responding xenografts had FBXW7 mutations at R465 and two had SMARCA4 mutations. Selinexor induced p53, p21, and cleaved PARP in several solid tumor models. CONCLUSIONS: Selinexor induced regression against several solid tumor and ALL xenografts and slowed tumor growth in a larger number of models. Pharmacodynamic effects for XPO1 inhibition were noted. Defining the relationship between selinexor systemic exposures in mice and humans will be important in assessing the clinical relevance of these results.
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Antineoplásicos/farmacología , Hidrazinas/farmacología , Carioferinas/antagonistas & inhibidores , Neoplasias Experimentales/tratamiento farmacológico , Receptores Citoplasmáticos y Nucleares/antagonistas & inhibidores , Triazoles/farmacología , Animales , Línea Celular Tumoral , Femenino , Humanos , Concentración 50 Inhibidora , Ratones , Ratones SCID , Ensayos Antitumor por Modelo de Xenoinjerto , Proteína Exportina 1RESUMEN
BACKGROUND: MK-8242 is an inhibitor of MDM2 that stabilizes the tumor suppressor TP53 and induces growth arrest or apoptosis downstream of TP53 induction. PROCEDURES: MK-8242 was tested against the Pediatric Preclinical Testing Program (PPTP) in vitro cell line panel at concentrations from 1.0 nM to 10.0 µM and against the PPTP in vivo xenograft panels using oral gavage on Days 1-5 and Day 15-19 at a dose of 125 mg/kg (solid tumors) or 75 mg/kg (acute lymphoblastic leukemia [ALL] models). RESULTS: The median IC50 for MK-8242 was 0.07 µM for TP53 wild-type cell lines versus >10 µM for TP53 mutant cell lines. MK-8242 induced a twofold or greater delay in time to event in 10 of 17 (59%) of TP53 wild-type solid tumor xenografts, excluding osteosarcoma xenografts that have very low TP53 expression. Objective responses were observed in seven solid tumor xenografts representing multiple histotypes. For the systemic-disease ALL panel, among eight xenografts there were two complete responses (CRs) and six partial responses (PRs). Two additional MLL-rearranged xenografts (MV4;11 and RS4;11) grown subcutaneously showed maintained CR and PR, respectively. The expected pharmacodynamic responses to TP53 activation were observed in TP53 wild-type models treated with MK-8242. Pharmacokinetic analysis showed that MK-8242 drug exposure in SCID mice appears to exceed that was observed in adult phase 1 trials. CONCLUSIONS: MK-8242-induced tumor regressions across multiple solid tumor histotypes and induced CRs or PRs for most ALL xenografts. This activity was observed at MK-8242 drug exposures that appear to exceed those observed in human phase 1 trials.