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2.
Cancers (Basel) ; 12(11)2020 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-33212828

RESUMO

Data regarding coronavirus disease 2019 (COVID-19) description are still limited in pediatric oncology. The French society of pediatric oncology (SFCE) initiated a study to better describe COVID-19 in patients followed in French pediatric oncology and hematology wards. All patients diagnosed with COVID-19 and followed in a SFCE center were enrolled. Data from medical records were analyzed for all patients enrolled up to the end of May 2020. Data were available for 37 patients. Thirty-one were children under 18 years of age. Nineteen patients were female. Seventeen patients had a solid tumor, 16 had a hematological malignancy and four recently underwent hematopoietic stem cell transplantation (HSCT) for non-oncological conditions. Twenty-eight patients presented symptoms, most often with fever, cough, rhinorrhea and asthenia. Ground-glass opacities were the most frequent radiological finding with abnormalities mostly bilateral and peripherally distributed. Twenty-four patients received chemotherapy a month prior to COVID-19 diagnosis. Most patients did not require hospitalization. Three patients required oxygen at the time of diagnosis. In total, five patients were admitted in an intensive care unit because of COVID-19 and one died from the disease. Children and young adults treated for a cancer and/or with a HSCT may be at risk for severe COVID-19 and should be closely monitored.

3.
Blood ; 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33067614

RESUMO

This Phase I study investigated the recommended Phase II dose (RP2D) of inotuzumab ozogamicin (InO), a CD22-directed antibody-drug conjugate, in pediatric patients with multiple-relapsed/refractory (R/R) CD22-positive acute lymphoblastic leukemia (ALL). Patients (≥1-<18 years) received three InO doses (Days 1, 8, 15) per course. Dose-escalation was based on dose-limiting toxicities (DLT) during Course 1 . Dose level 1 (DL1)=1.4 mg/m2 (0.6-0.4-0.4 mg/m2); DL2=1.8 mg/m2 (0.8-0.5-0.5 mg/m2). Secondary endpoints included safety, anti-leukemic activity, and pharmacokinetics. Twenty-five patients (23 evaluable for DLT) were enrolled. In Course 1, first cohort, 1/6 (DL1) and 2/5 (DL2) patients experienced DLTs; subsequent review considered DL2 DLTs to be non-dose-limiting. Dose was de-escalated to DL1 while awaiting protocol amendment to re-evaluate DL2 in a second cohort, where 0/6 (DL1) and 1/6 (DL2) patients had a DLT. Twenty-three patients experienced Grade 3-4 adverse events; hepatic sinusoidal obstruction syndrome was reported in two patients after subsequent chemotherapy. Overall response rate after Course 1 was 80% [95% CI: 59-93%] (20/25 patients; DL1=75% [43-95%], DL2=85% [55-98%]); 84% [60-97%] of responders obtained minimal residual disease-negative CR; 12-month overall survival was 40% [95% CI: 25-66%]. Nine patients received hematopoietic stem cell transplant or chimeric-antigen receptor T-cells after InO. InO median maximum concentrations were comparable to simulated adult concentrations. InO was well tolerated, demonstrating anti-leukemic activity in heavily pre-treated children with CD22-positive R/R ALL. RP2D was established as 1.8 mg/m2/course, as in adults.

6.
Bull Cancer ; 107(6): 629-632, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32387061

RESUMO

Since the emergence of the SARS-CoV-2 infection, many recommendations have been made. However, the very nature of acute lymphoblastic leukemias and their treatment in children and adolescents led the Leukemia Committee of the French Society for the fight against cancers and leukemias in children and adolescents (SFCE) to propose more specific recommendations, even if data for this population are still scarce. They may have to evolve according to the rapid evolution of knowledge on COVID-19.


Assuntos
Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiologia , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Antivirais/farmacocinética , Antivirais/uso terapêutico , Criança , Técnicas de Laboratório Clínico , Terapia Combinada , Comorbidade , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/prevenção & controle , Gerenciamento Clínico , Síndrome de Down/epidemiologia , Interações Medicamentosas , Neutropenia Febril/induzido quimicamente , Neutropenia Febril/tratamento farmacológico , Neutropenia Febril/prevenção & controle , Feminino , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Hospedeiro Imunocomprometido , Masculino , Pandemias/prevenção & controle , Pneumonia Viral/diagnóstico , Pneumonia Viral/prevenção & controle , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Recidiva , Indução de Remissão , Risco , Medição de Risco , Terapia de Salvação , Avaliação de Sintomas
9.
J Clin Oncol ; 37(25): 2246-2256, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31283407

RESUMO

PURPOSE: Infant acute lymphoblastic leukemia (ALL) is characterized by KMT2A (MLL) gene rearrangements and coexpression of myeloid markers. The Interfant-06 study, comprising 18 national and international study groups, tested whether myeloid-style consolidation chemotherapy is superior to lymphoid style, the role of stem-cell transplantation (SCT), and which factors had independent prognostic value. MATERIALS AND METHODS: Three risk groups were defined: low risk (LR): KMT2A germline; high risk (HR): KMT2A-rearranged and older than 6 months with WBC count 300 × 109/L or more or a poor prednisone response; and medium risk (MR): all other KMT2A-rearranged cases. Patients in the MR and HR groups were randomly assigned to receive the lymphoid course low-dose cytosine arabinoside [araC], 6-mercaptopurine, cyclophosphamide (IB) or experimental myeloid courses, namely araC, daunorubicin, etoposide (ADE) and mitoxantrone, araC, etoposide (MAE). RESULTS: A total of 651 infants were included, with 6-year event-free survival (EFS) and overall survival of 46.1% (SE, 2.1) and 58.2% (SE, 2.0). In West European/North American groups, 6-year EFS and overall survival were 49.4% (SE, 2.5) and 62.1% (SE, 2.4), which were 10% to 12% higher than in other countries. The 6-year probability of disease-free survival was comparable for the randomized arms (ADE+MAE 39.3% [SE 4.0; n = 169] v IB 36.8% [SE, 3.9; n = 161]; log-rank P = .47). The 6-year EFS rate of patients in the HR group was 20.9% (SE, 3.4) with the intention to undergo SCT; only 46% of them received SCT, because many had early events. KMT2A rearrangement was the strongest prognostic factor for EFS, followed by age, WBC count, and prednisone response. CONCLUSION: Early intensification with postinduction myeloid-type chemotherapy courses did not significantly improve outcome for infant ALL compared with the lymphoid-type course IB. Outcome for infant ALL in Interfant-06 did not improve compared with that in Interfant-99.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Ciclofosfamida/administração & dosagem , Citarabina/administração & dosagem , Daunorrubicina/administração & dosagem , Intervalo Livre de Doença , Etoposídeo/administração & dosagem , Feminino , Rearranjo Gênico , Mutação em Linhagem Germinativa , Histona-Lisina N-Metiltransferase/genética , Humanos , Lactente , Recém-Nascido , Masculino , Mercaptopurina/administração & dosagem , Mitoxantrona/administração & dosagem , Proteína de Leucina Linfoide-Mieloide/genética , Taxa de Sobrevida , Resultado do Tratamento
10.
12.
Arch Dis Child ; 104(10): 947-952, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30472665

RESUMO

OBJECTIVE: To analyse parents' and children's understanding of consent information and assess their decision-making process in paediatric oncology. DESIGN: Prospective observational study. SETTINGS: Eleven French paediatric oncology units. PATIENTS: Parents and children who have been asked to give consent for participation in an early phase trial. INTERVENTIONS: Thirty-seven children and 119 parents were questioned using an audio-recorded semistructured interview. MAIN OUTCOME MEASURES: The participants' understanding of nine elements of the informed consent was assessed by comparing their answers with the informed consent leaflet. Their decision-making process was also evaluated. RESULTS: Most parents and children had an excellent understanding regarding their participation in a clinical trial (respectively 88.2% and 48.6%), the right to withdraw (76.5% and 43.2%) and the prospects of collective benefits (74.8% and 48.6%). By contrast, less than half of the parents and few of the children correctly understood the alternatives (respectively 47.5% and 27%), the risks related to participation (44.5% and 10.8%), the prospects of individual benefits (33.6% and 10.8%) and the purpose of the clinical trial (12.6% and 2.7%). Twenty-six (70.3%) children participated in the decision-making process. Most parents and children felt they had no choice but to participate in the trial to have access to a new anticancer treatment. CONCLUSIONS: What might appear to be a poor understanding of the research protocol may actually correspond to the families' interpretation of the situation as a coping mechanism. All children (except infants) should get age-tailored information in order for them to have a meaningful involvement in research.


Assuntos
Ensaios Clínicos Fase I como Assunto , Compreensão , Tomada de Decisões , Consentimento Livre e Esclarecido , Pais , Participação do Paciente , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Neoplasias/terapia , Estudos Prospectivos
13.
Haematologica ; 103(9): 1484-1492, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29773602

RESUMO

Survival in children with relapsed/refractory acute myeloid leukemia is unsatisfactory. Treatment consists of one course of fludarabine, cytarabine and liposomal daunorubicin, followed by fludarabine and cytarabine and stem-cell transplantation. Study ITCC 020/I-BFM 2009-02 aimed to identify the recommended phase II dose of clofarabine replacing fludarabine in the abovementioned combination regimen (3+3 design). Escalating dose levels of clofarabine (20-40 mg/m2/day × 5 days) and liposomal daunorubicin (40-80 mg/m2/day) were administered with cytarabine (2 g/m2/day × 5 days). Liposomal DNR was given on day 1, 3 and 5 only. The cohort at the recommended phase II dose was expanded to make a preliminary assessment of anti-leukemic activity. Thirty-four children were enrolled: refractory 1st (n=11), early 1st (n=15), ≥2nd relapse (n=8). Dose level 3 (30 mg/m2clofarabine; 60 mg/m2liposomal daunorubicin) appeared to be safe only in patients without subclinical fungal infections. Infectious complications were dose-limiting. The recommended phase II dose was 40 mg/m2 clofarabine with 60 mg/m2 liposomal daunorubicin. Side-effects mainly consisted of infections. The overall response rate was 68% in 31 response evaluable patients, and 80% at the recommended phase II dose (n=10); 22 patients proceeded to stem cell transplantation. The 2-year probability of event-free survival (pEFS) was 26.5±7.6 and probability of survival (pOS) 32.4±8.0%. In the 21 responding patients, the 2-year pEFS was 42.9±10.8 and pOS 47.6±10.9%. Clofarabine exposure in plasma was not significantly different from that in single-agent studies. In conclusion, clofarabine was well tolerated and showed high response rates in relapsed/refractory pediatric acute myeloid leukemia. Patients with (sub) clinical fungal infections should be treated with caution. Clofarabine has been taken forward in the Berlin-Frankfurt-Münster study for newly diagnosed acute myeloid leukemia. The Study ITCC-020 was registered as EUDRA-CT 2009-009457-13; Dutch Trial Registry number 1880.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Leucemia Mieloide Aguda/tratamento farmacológico , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Criança , Pré-Escolar , Clofarabina/administração & dosagem , Clofarabina/farmacocinética , Citarabina/administração & dosagem , Citarabina/farmacocinética , Daunorrubicina/administração & dosagem , Daunorrubicina/farmacocinética , Esquema de Medicação , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Lactente , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/mortalidade , Lipossomos , Masculino , Recidiva , Indução de Remissão , Retratamento , Análise de Sobrevida , Resultado do Tratamento , Adulto Jovem
14.
Blood ; 131(3): 289-300, 2018 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-29051182

RESUMO

Risk stratification in childhood T-cell acute lymphoblastic leukemia (T-ALL) is mainly based on minimal residual disease (MRD) quantification. Whether oncogenetic mutation profiles can improve the discrimination of MRD-defined risk categories was unknown. Two hundred and twenty FRALLE2000T-treated patients were tested retrospectively for NOTCH1/FBXW7/RAS and PTEN alterations. Patients with NOTCH1/FBXW7 (N/F) mutations and RAS/PTEN (R/P) germ line (GL) were classified as oncogenetic low risk (gLoR; n = 111), whereas those with N/F GL and R/P GL mutations or N/F and R/P mutations were classified as high risk (gHiR; n = 109). Day 35 MRD status was available for 191 patients. Five-year cumulative incidence of relapse (CIR) and disease-free survival were 36% and 60% for gHiR patients and 11% and 89% for gLoR patients, respectively. Importantly, among the 60% of patients with MRD <10-4, 5-year CIR was 29% for gHiR patients and 4% for gLoR patients. Based on multivariable Cox models and stepwise selection, the 3 most discriminating variables were the oncogenetic classifier, MRD, and white blood cell (WBC) count. Patients harboring a WBC count ≥200 × 109/L, gHiR classifier, and MRD ≥10-4 demonstrated a 5-year CIR of 46%, whereas the 58 patients (30%) with a WBC count <200 × 109/L, gLoR classifier, and MRD <10-4 had a very low risk of relapse, with a 5-year CIR of only 2%. In childhood T-ALL, the N/F/R/P mutation profile is an independent predictor of relapse. When combined with MRD and a WBC count ≥200 × 109/L, it identifies a significant subgroup of patients with a low risk of relapse.


Assuntos
Mutação/genética , Neoplasia Residual/genética , Oncogenes/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Adolescente , Criança , Pré-Escolar , Intervalo Livre de Doença , Genes Neoplásicos , Humanos , Lactente , Recém-Nascido , Contagem de Leucócitos , Neoplasia Residual/sangue , Prognóstico , Recidiva , Resultado do Tratamento
15.
J Pediatr Hematol Oncol ; 39(5): 365-369, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28486259

RESUMO

To study the management of acute appendicitis in neutropenic patients, we retrospectively reviewed cases of acute appendicitis in neutropenic children treated for cancer. The patients' demographics, medical records, and outcomes were tracked. We compared nonoperative treatment versus emergency or delayed surgery. The cases of 30 patients with a mean age of 8.8 years in 12 French departments of Pediatric Hematology/Oncology between 1995 and 2013 were studied. Most patients (90%) were treated for hematological malignancies. Seven of the 30 children were successfully treated with exclusive medical treatment. Early surgery was performed in 6 patients, and the remaining 17 underwent combined management with a first-line antibiotic treatment and delayed appendectomy. Treatments were successful in all cases with transitory complications in only 3 patients. No death linked to infection was reported. Surgery was well tolerated even in the neutropenic period. Appendix perforation was a major risk factor of prolonged hospitalization. Histologic as well as bacteriologic and mycologic/parasitologic analyses were required in case of surgery. Analysis of diagnostic assessments showed the major importance of imaging (ultrasonography and tomography) on diagnosis confirmation. We could not come to a conclusion in the few numbers of reviewed cases because of a significant difference in management strategies, but we can conclude that early surgery after adequate supportive care is an acceptable modality of treatment and must be chosen in the face of life-threatening conditions.


Assuntos
Apendicite/complicações , Apendicite/terapia , Neutropenia/complicações , Adolescente , Apendicite/cirurgia , Criança , Pré-Escolar , Diagnóstico por Imagem , Feminino , Humanos , Lactente , Tempo de Internação , Masculino , Estudos Retrospectivos , Tempo para o Tratamento , Resultado do Tratamento
16.
J Clin Oncol ; 34(36): 4381-4389, 2016 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-27998223

RESUMO

Purpose Blinatumomab is a bispecific T-cell engager antibody construct targeting CD19 on B-cell lymphoblasts. We evaluated the safety, pharmacokinetics, recommended dosage, and potential for efficacy of blinatumomab in children with relapsed/refractory B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Methods This open-label study enrolled children < 18 years old with relapsed/refractory BCP-ALL in a phase I dosage-escalation part and a phase II part, using 6-week treatment cycles. Primary end points were maximum-tolerated dosage (phase I) and complete remission rate within the first two cycles (phase II). Results We treated 49 patients in phase I and 44 patients in phase II. Four patients had dose-limiting toxicities in cycle 1 (phase I). Three experienced grade 4 cytokine-release syndrome (one attributed to grade 5 cardiac failure); one had fatal respiratory failure. The maximum-tolerated dosage was 15 µg/m2/d. Blinatumomab pharmacokinetics was linear across dosage levels and consistent among age groups. On the basis of the phase I data, the recommended blinatumomab dosage for children with relapsed/refractory ALL was 5 µg/m2/d for the first 7 days, followed by 15 µg/m2/d thereafter. Among the 70 patients who received the recommended dosage, 27 (39%; 95% CI, 27% to 51%) achieved complete remission within the first two cycles, 14 (52%) of whom achieved complete minimal residual disease response. The most frequent grade ≥ 3 adverse events were anemia (36%), thrombocytopenia (21%), and hypokalemia (17%). Three patients (4%) and one patient (1%) had cytokine-release syndrome of grade 3 and 4, respectively. Two patients (3%) interrupted treatment after grade 2 seizures. Conclusion This trial, which to the best of our knowledge was the first such trial in pediatrics, demonstrated antileukemic activity of single-agent blinatumomab with complete minimal residual disease response in children with relapsed/refractory BCP-ALL. Blinatumomab may represent an important new treatment option in this setting, requiring further investigation in curative indications.


Assuntos
Anticorpos Biespecíficos/uso terapêutico , Dose Máxima Tolerável , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Adolescente , Antineoplásicos/efeitos adversos , Antineoplásicos/uso terapêutico , Criança , Pré-Escolar , Intervalo Livre de Doença , Relação Dose-Resposta a Droga , Esquema de Medicação , Seguimentos , Humanos , Infusões Intravenosas , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Método Simples-Cego , Análise de Sobrevida , Resultado do Tratamento
17.
Bull Cancer ; 103(3): 299-311, 2016 Mar.
Artigo em Francês | MEDLINE | ID: mdl-26826739

RESUMO

If acute leukemia is the most frequent cancer in childhood (33%), it remains a very rare diagnosis in infants less than one year old, e.g. less than 5% of cases. At this age, the frequency of acute lymphoblastic leukemia (ALL) (almost all of B-lineage) is quite similar to the one of myeloblastic forms (AML). Infant leukemia frequently presents with high hyperleucocytosis, major tumoral burden and numerous extra-hematological features, especially in central nervous system and skin. Whatever the lineage, the leukemic cell is often very immature cytologically and immunologically. Rearrangements of the Mixed Lineage Leukemia (MLL) gene, located on band 11q23, are the hallmark of these immature leukemias and confer a particular resistance to conventional approaches, corticosteroids and chemotherapy. The immaturity of infants less than 1-year-old is associated to a decrease of the tolerable dose-intensity of some drugs (anthracyclines, alkylating agents) or asks questions about some procedures like radiotherapy or high dose conditioning regimen, responsible of inacceptable acute and late toxicities. The high level of severe infectious diseases and other high-grade side effects limits also the capacity to cure these infants. The survival of infants less than 1-year-old with AML is only 50% but similar to older children. On the other hand, survival of those with ALL is the same, then quite limited comparing the 80% survival in children over one year. Allogeneic stem cell transplantations are indicated in high-risk subgroups of infant ALL (age below 6 months, high hyperleucocytosis >300.10(9)/L, MLL-rearrangement, initial poor prednisone response). However, morbidity and mortality remain very important and these approaches cannot be extended to all cases. During the neonatal period, the dismal prognosis linked to the high number of primary failures or very early relapses and uncertainties about the late toxicities question physicians about ethics. It is an emergency to propose different strategies (targeted therapies) to these infants with acute leukemia as conventional trials failed to improve outcome.


Assuntos
Leucemia Mieloide Aguda , Leucemia-Linfoma Linfoblástico de Células Precursoras , Doenças Raras , Fatores Etários , Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/administração & dosagem , Rearranjo Gênico , Humanos , Lactente , Recém-Nascido , Leucemia Aguda Bifenotípica/genética , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/patologia , Leucemia Mieloide Aguda/terapia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Doenças Raras/genética , Doenças Raras/mortalidade , Doenças Raras/patologia , Doenças Raras/terapia , Recidiva , Transplante de Células-Tronco
18.
Pediatr Blood Cancer ; 63(2): 270-5, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26376115

RESUMO

BACKGROUND: Current outcome of very early relapse of acute lymphoblastic leukemia (ALL) in children remains poor. As a single agent, clofarabine provided a response rate of 26% in childhood ALL second relapse and, in combination with cyclophosphamide and etoposide, a 44% complete remission and complete remission without platelet recovery (CR+CRp) rate. Further multi-drug combinations need to be investigated. We used the VANDA regimen as a template, cytarabine being replaced by clofarabine. PATIENTS AND METHODS: A phase I study combining escalating doses of clofarabine (25% increments from 20 to 40 mg/m(2)/d) with fixed doses of mitoxantrone, etoposide, asparaginase, and dexamethasone was undertaken in children presenting with very early or second or post-transplant ALL relapse. RESULTS: Twenty patients were enrolled, 19 were evaluable. Four patients had previously been allografted. Dose-limiting toxicity (DLT) appeared at dose level 3 (32 mg/m(2)), one out of six patients experienced a liver DLT. At dose level 4 (40 mg/m(2)), four DLT occurred (two fungal infection and two liver DLT). The maximum tolerated dose (MTD) of clofarabine was thus determined to be 32 mg/m(2). There was no toxic death. Eleven (57.9%) patients achieved a CR. Six patients proceeded to allogeneic stem cell transplantation. CONCLUSION: Clofarabine MTD was 32 mg/m(2)/d in this combination which appeared feasible and effective in this population.


Assuntos
Nucleotídeos de Adenina/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Arabinonucleosídeos/administração & dosagem , Recidiva Local de Neoplasia/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Nucleotídeos de Adenina/efeitos adversos , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Arabinonucleosídeos/efeitos adversos , Asparaginase/uso terapêutico , Criança , Pré-Escolar , Clofarabina , Dexametasona/uso terapêutico , Relação Dose-Resposta a Droga , Etoposídeo/uso terapêutico , Feminino , Humanos , Masculino , Dose Máxima Tolerável , Mitoxantrona/uso terapêutico , Terapia de Salvação/métodos , Adulto Jovem
20.
Hum Mol Genet ; 23(16): 4315-27, 2014 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-24705357

RESUMO

RASopathies, a family of disorders characterized by cardiac defects, defective growth, facial dysmorphism, variable cognitive deficits and predisposition to certain malignancies, are caused by constitutional dysregulation of RAS signalling predominantly through the RAF/MEK/ERK (MAPK) cascade. We report on two germline mutations (p.Gly39dup and p.Val55Met) in RRAS, a gene encoding a small monomeric GTPase controlling cell adhesion, spreading and migration, underlying a rare (2 subjects among 504 individuals analysed) and variable phenotype with features partially overlapping Noonan syndrome, the most common RASopathy. We also identified somatic RRAS mutations (p.Gly39dup and p.Gln87Leu) in 2 of 110 cases of non-syndromic juvenile myelomonocytic leukaemia, a childhood myeloproliferative/myelodysplastic disease caused by upregulated RAS signalling, defining an atypical form of this haematological disorder rapidly progressing to acute myeloid leukaemia. Two of the three identified mutations affected known oncogenic hotspots of RAS genes and conferred variably enhanced RRAS function and stimulus-dependent MAPK activation. Expression of an RRAS mutant homolog in Caenorhabditis elegans enhanced RAS signalling and engendered protruding vulva, a phenotype previously linked to the RASopathy-causing SHOC2(S2G) mutant. Overall, these findings provide evidence of a functional link between RRAS and MAPK signalling and reveal an unpredicted role of enhanced RRAS function in human disease.


Assuntos
Carcinogênese/genética , Mutação/fisiologia , Fenótipo , Proteínas ras/genética , Animais , Caenorhabditis elegans , Estudos de Coortes , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mielomonocítica Juvenil/genética , MAP Quinase Quinase Quinases/metabolismo , Síndrome de Noonan/genética , Proteína Oncogênica v-akt/metabolismo , Transdução de Sinais/genética , Proteínas ras/química , Proteínas ras/metabolismo
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