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1.
Gene ; 705: 67-76, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-30991098

RESUMO

Medulloblastoma (MB) is characterized by highly invasive embryonal neuro-epithelial tumors that metastasize via cerebrospinal fluid. MB is difficult to treat and the chemotherapy is associated with significant toxicities and potential long-term disabilities. Previously, we showed that small molecule, clotam (tolfenamic acid: TA) inhibited MB cell proliferation and tumor growth in mice by targeting, survivin. Overexpression of survivin is associated with aggressiveness and poor prognosis in several cancers, including MB. The aim of this study was to test combination treatment involving Vincristine® (VCR), a standard chemotherapeutic drug for MB and TA against MB cells. DAOY and D283 MB cells were treated with 10 µg/mL TA or VCR (DAOY: 2 ng/mL; D283: 1 ng/mL) or combination (TA + VCR). These optimized doses were lower than individual IC50 values. The effect of single or combination treatment on cell viability (CellTiterGlo kit), Combination Index (Chou-Talalay method based on median-drug effect analysis), activation of apoptosis and cell cycle modulation (by flow cytometry using Annexin V and propidium iodide respectively) and the expression of associated markers including survivin (Western immunoblot) were determined. Combination Index showed moderate synergistic cytotoxic effect in both cells. When compared to individual agents, the combination of TA and VCR increased MB cell growth inhibition, induced apoptosis and caused cell cycle (G2/M phase) arrest. Survivin expression was also decreased by the combination treatment. TA is effective for inducing the anti-proliferative response of VCR in MB cells. MB has four distinct genetic/molecular subgroups. Experiments were conducted with MB cells representing two subgroups (DAOY: SHH group; D283: group 4/3). TA-induced inhibition of survivin expression potentially destabilizes mitotic microtubule assembly, sensitizing MB cells and enhancing the efficacy of VCR.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias Cerebelares/metabolismo , Meduloblastoma/metabolismo , Survivina/metabolismo , Vincristina/farmacologia , ortoaminobenzoatos/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias Cerebelares/tratamento farmacológico , Relação Dose-Resposta a Droga , Regulação para Baixo , Sinergismo Farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Meduloblastoma/tratamento farmacológico
2.
Apoptosis ; 24(1-2): 21-32, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30610505

RESUMO

Current therapeutic strategies used in Ewing sarcoma (ES) especially for relapsed patients have resulted in modest improvements in survival over the past 20 years. Combination therapeutic approach presents as an alternative to overcoming drug resistance in metastatic ES. This study evaluated the effect of Clotam (tolfenamic acid or TA), a small molecule and inhibitor of Specificity protein1 (Sp1) and survivin for sensitizing ES cell lines to chemotherapeutic agent, vincristine (VCR). ES cells (CHLA-9 and TC-32) were treated with TA or VCR or TA + VCR (combination), and cell viability was assessed after 24/48/72 h. Effect of TA or VCR or TA + VCR treatment on cell cycle arrest and apoptosis were evaluated using propidium iodide, cell cycle assay and Annexin V flow cytometry respectively. The apoptosis markers, caspase 3/7 (activity levels) and cleaved-PARP (protein expression) were measured. Cardiomyocytes, H9C2 were used as non-malignant cells. While, all treatments caused time- and dose-dependent inhibition of cell viability, interestingly, combination treatment caused significantly higher response (~ 80% inhibition, p < 0.05). Cell viability inhibition was accompanied by inhibition of Sp1 and Survivin. TA + VCR treatment significantly (p < 0.05) increased caspase 3/7 activity which strongly correlated with upregulated c-PARP level and Annexin V staining. Cell cycle arrest was observed at G0/G1 (TA) or G2/M (VCR and TA + VCR). All treatments did not cause cytotoxicity in H9C2 cells. These results suggest that TA could enhance the anti-cancer activity of VCR in ES cells. Therefore, TA + VCR combination could be further tested to develop as safe/effective therapeutic strategy for treating ES.

3.
Blood ; 133(7): 724-729, 2019 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-30510082

RESUMO

Acute lymphoblastic leukemia (ALL) is the most common malignancy in children. Characterized by high levels of Native American ancestry, Hispanics are disproportionally affected by this cancer with high incidence and inferior survival. However, the genetic basis for this disparity remains poorly understood because of a paucity of genome-wide investigation of ALL in Hispanics. Performing a genome-wide association study (GWAS) in 940 Hispanic children with ALL and 681 ancestry-matched non-ALL controls, we identified a novel susceptibility locus in the ERG gene (rs2836365; P = 3.76 × 10-8; odds ratio [OR] = 1.56), with independent validation (P = .01; OR = 1.43). Imputation analyses pointed to a single causal variant driving the association signal at this locus overlapping with putative regulatory DNA elements. The effect size of the ERG risk variant rose with increasing Native American genetic ancestry. The ERG risk genotype was underrepresented in ALL with the ETV6-RUNX1 fusion (P < .0005) but enriched in the TCF3-PBX1 subtype (P < .05). Interestingly, ALL cases with germline ERG risk alleles were significantly less likely to have somatic ERG deletion (P < .05). Our results provide novel insights into genetic predisposition to ALL and its contribution to racial disparity in this cancer.


Assuntos
Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Hispano-Americanos/genética , Proteínas de Fusão Oncogênica/genética , Polimorfismo de Nucleotídeo Único , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Doença Aguda , Estudos de Casos e Controles , Criança , Feminino , Seguimentos , Genótipo , Humanos , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras B/classificação , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Prognóstico , Regulador Transcricional ERG/genética
4.
Cancer Cell ; 33(5): 937-948.e8, 2018 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-29681510

RESUMO

Somatic genetic alterations of IKZF1, which encodes the lymphoid transcription factor IKAROS, are common in high-risk B-progenitor acute lymphoblastic leukemia (ALL) and are associated with poor prognosis. Such alterations result in the acquisition of stem cell-like features, overexpression of adhesion molecules causing aberrant cell-cell and cell-stroma interaction, and decreased sensitivity to tyrosine kinase inhibitors. Here we report coding germline IKZF1 variation in familial childhood ALL and 0.9% of presumed sporadic B-ALL, identifying 28 unique variants in 45 children. The majority of variants adversely affected IKZF1 function and drug responsiveness of leukemic cells. These results identify IKZF1 as a leukemia predisposition gene, and emphasize the importance of germline genetic variation in the development of both familial and sporadic ALL.


Assuntos
Mutação em Linhagem Germinativa , Fator de Transcrição Ikaros/genética , Fator de Transcrição Ikaros/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Animais , Criança , Feminino , Mutação da Fase de Leitura , Predisposição Genética para Doença , Humanos , Masculino , Camundongos , Transplante de Neoplasias , Linhagem , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Análise de Sequência de DNA
5.
J Clin Oncol ; 36(6): 591-599, 2018 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-29300620

RESUMO

Purpose Germline TP53 variation is the genetic basis of Li-Fraumeni syndrome, a highly penetrant cancer predisposition condition. Recent reports of germline TP53 variants in childhood hypodiploid acute lymphoblastic leukemia (ALL) suggest that this type of leukemia is another manifestation of Li-Fraumeni syndrome; however, the pattern, prevalence, and clinical relevance of TP53 variants in childhood ALL remain unknown. Patients and Methods Targeted sequencing of TP53 coding regions was performed in 3,801 children from the Children's Oncology Group frontline ALL clinical trials, AALL0232 and P9900. TP53 variant pathogenicity was evaluated according to experimentally determined transcriptional activity, in silico prediction of damaging effects, and prevalence in non-ALL control populations. TP53 variants were analyzed for their association with ALL presenting features and treatment outcomes. Results We identified 49 unique nonsilent rare TP53 coding variants in 77 (2.0%) of 3,801 patients sequenced, of which 22 variants were classified as pathogenic. TP53 pathogenic variants were significantly over-represented in ALL compared with non-ALL controls (odds ratio, 5.2; P < .001). Children with TP53 pathogenic variants were significantly older at ALL diagnosis (median age, 15.5 years v 7.3 years; P < .001) and were more likely to have hypodiploid ALL (65.4% v 1.2%; P < .001). Carrying germline TP53 pathogenic variants was associated with inferior event-free survival and overall survival (hazard ratio, 4.2 and 3.9; P < .001 and .001, respectively). In particular, children with TP53 pathogenic variants were at a dramatically higher risk of second cancers than those without pathogenic variants, with 5-year cumulative incidence of 25.1% and 0.7% ( P < .001), respectively. Conclusion Loss-of-function germline TP53 variants predispose children to ALL and to adverse treatment outcomes with ALL therapy, particularly the risk of second malignant neoplasms.


Assuntos
Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Proteína Supressora de Tumor p53/genética , Adolescente , Criança , Feminino , Humanos , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras B/mortalidade , Prognóstico
6.
J Pediatr Hematol Oncol ; 40(2): 104-110, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29045268

RESUMO

Obesity following treatment of pediatric acute lymphoblastic leukemia (ALL) has become a significant long-term concern. Excessive weight gain often occurs during treatment, particularly during induction and the first 6 months of maintenance therapy, and it may be potentially modifiable. This retrospective study aimed to evaluate the impact of an early, 3-visit nutrition intervention on weight gain during maintenance therapy in ALL patients. Medical records of the intervention group were compared with historical controls who were treated on the same ALL treatment protocols during an earlier time period. Anthropometrics were collected throughout intensive therapy and at every monthly visit during the first 12 months of maintenance therapy. In total, 67 patients were evaluated (33 in the intervention group and 34 in the control group). After controlling for significant predictors of body mass index (BMI) z-scores in maintenance therapy-including higher BMI at diagnosis and weight gain throughout intensive therapy-the intervention group demonstrated more controlled weight gain during maintenance therapy (P<0.0001). A 3-visit nutrition intervention was effective in attenuating weight gain trends during ALL maintenance therapy.


Assuntos
Antineoplásicos/efeitos adversos , Obesidade Pediátrica/induzido quimicamente , Obesidade Pediátrica/dietoterapia , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Criança , Pré-Escolar , Dietoterapia/métodos , Feminino , Humanos , Lactente , Masculino , Obesidade Pediátrica/prevenção & controle , Estudos Retrospectivos , Ganho de Peso
7.
JMIR Cancer ; 3(1): e2, 2017 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-28410182

RESUMO

BACKGROUND: Survivors of pediatric acute lymphoblastic leukemia (ALL) may experience unhealthy weight gain during treatment, which has been associated with higher risk for chronic health issues. OBJECTIVE: The purpose of this study was to obtain feedback on weight management in pediatric ALL survivors and on the content and implementation of a Web-based weight management program. METHODS: Study participants included 54 parent survey respondents and 19 pediatric oncology professionals in 4 focus groups. Survey questions included report of child weight status and interest in participating in weight management programming at various time points. Pediatric oncology professionals were asked about the preferred topics and timing, as well as their role. Focus group data were analyzed by a multidisciplinary research team for common themes. RESULTS: The mean age of survivors was 6.5 years. By parent report, 19% of children were overweight and 25% were obese. Preferred timing for weight management program participation was within 3 months of starting maintenance chemotherapy (23/53, 43%) or within 12 months after completion of all cancer treatments (18/53, 34%). Pediatric oncology professionals likewise considered the maintenance phase appropriate. They considered parenting to be an important topic to include and indicated that their most appropriate roles would be promotion and support. CONCLUSIONS: Parents and pediatric oncology professionals are interested in and supportive of early weight management in pediatric ALL survivors. Future research needs to identify strategies to integrate this into pediatric cancer care and to evaluate the feasibility and efficacy of these strategies.

8.
Cell Physiol Biochem ; 39(5): 1695-1704, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27642750

RESUMO

BACKGROUND/AIMS: The role of lipid profile in predicting the risk of Type 2 diabetes mellitus (T2DM) in children is not clearly established. Our aim is to screen non-diabetic children aged 10-14 years for risk of developing T2DM and evaluate the association of abnormal lipids and socioeconomic status (SES). METHODS: Data on race/ethnicity, family history, body mass index percentile, blood pressure and presence of neck pigmentation (acanthosis nigricans) were collected from 149 non-diabetic children. Using these factors, children were classified into low risk (<3 risk factors) and high risk (>3 risk factors) groups. Logistic regression model and chi-square tests were used to evaluate the association of blood lipid profile and demographic variables. Independent t-test was used to compare the ratio of Total Cholesterol (TC) and High Density Lipids (HDL) with T2DM risk. RESULTS: 60% of children were at high risk for developing T2DM. HDL (p<0.001), triglycerides (p=0.02) and TC/HDL ratio (p<.001) were significantly abnormal in high risk group. Low SES showed a marginal association with high risk group. There were no gender or age differences between high and low risk groups. CONCLUSIONS: The significant determinants associated with high risk group were modifiable factors providing an opportunity for early intervention and prevention.


Assuntos
Glicemia/metabolismo , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Triglicerídeos/sangue , Acantose Nigricans/diagnóstico , Acantose Nigricans/etnologia , Acantose Nigricans/fisiopatologia , Adolescente , Grupo com Ancestrais do Continente Africano , Pressão Sanguínea/fisiologia , Índice de Massa Corporal , Criança , Estudos Transversais , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/etnologia , Grupo com Ancestrais do Continente Europeu , Feminino , Voluntários Saudáveis , Hispano-Americanos , Humanos , Modelos Logísticos , Masculino , Prognóstico , Fatores de Risco , Classe Social , Texas
9.
J Clin Oncol ; 34(18): 2133-40, 2016 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-27114598

RESUMO

PURPOSE: Acute pancreatitis is one of the common causes of asparaginase intolerance. The mechanism is unknown, and genetic predisposition to asparaginase-induced pancreatitis has not been previously identified. METHODS: To determine clinical risk factors for asparaginase-induced pancreatitis, we studied a cohort of 5,185 children and young adults with acute lymphoblastic leukemia, including 117 (2.3%) who were diagnosed with at least one episode of acute pancreatitis during therapy. A genome-wide association study was performed in the cohort and in an independent case-control group of 213 patients to identify genetic risk factors. RESULTS: Risk factors associated with pancreatitis included genetically defined Native American ancestry (P < .001), older age (P < .001), and higher cumulative dose of asparaginase (P < .001). No common variants reached genome-wide significance in the genome-wide association study, but a rare nonsense variant rs199695765 in CPA2, encoding carboxypeptidase A2, was highly associated with pancreatitis (hazard ratio, 587; 95% CI, 66.8 to 5166; P = 9.0 × 10(-9)). A gene-level analysis showed an excess of additional CPA2 variants in patients who did versus those who did not develop pancreatitis (P = .001). Sixteen CPA2 single-nucleotide polymorphisms were associated (P < .05) with pancreatitis, and 13 of 24 patients who carried at least one of these variants developed pancreatitis. Biologic functions that were overrepresented by common variants modestly associated with pancreatitis included purine metabolism and cytoskeleton regulation. CONCLUSION: Older age, higher exposure to asparaginase, and higher Native American ancestry were independent risk factors for pancreatitis in patients with acute lymphoblastic leukemia. Those who inherit a nonsense rare variant in the CPA2 gene had a markedly increased risk of asparaginase-induced pancreatitis.


Assuntos
Carboxipeptidases A/genética , Pancreatite/etiologia , Polimorfismo de Nucleotídeo Único , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicações , Doença Aguda , Adolescente , Adulto , Asparaginase/efeitos adversos , Criança , Pré-Escolar , Estudo de Associação Genômica Ampla , Humanos , Lactente , Recém-Nascido , Pancreatite/genética , Fatores de Risco
11.
Lancet Oncol ; 16(16): 1659-66, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26522332

RESUMO

BACKGROUND: Hereditary predisposition is rarely suspected for childhood acute lymphoblastic leukaemia (ALL). Recent reports of germline ETV6 variations associated with substantial familial clustering of haematological malignancies indicated that this gene is a potentially important genetic determinant for ALL susceptibility. Our aims in this study were to comprehensively identify ALL predisposition variants in ETV6 and to determine the extent to which they contributed to the overall risk of childhood ALL. METHODS: Whole-exome sequencing of an index family with several cases of ALL was done to identify causal variants for ALL predisposition. Targeted sequencing of ETV6 was done in children from the Children's Oncology Group and St Jude Children's Research Hospital front-line ALL trials. Patients were included in this study on the basis of their enrolment in these clinical trials and the availability of germline DNA. ETV6 variant genotypes were compared with non-ALL controls to define ALL-related germline risk variants. ETV6 variant function was characterised bioinformatically and correlated with clinical and demographic features in children with ALL. FINDINGS: We identified a novel non-sense ETV6 variant (p.Arg359X) with a high penetrance in an index family. Subsequent targeted sequencing of ETV6 in 4405 childhood ALL cases identified 31 exonic variants (four non-sense, 21 missense, one splice site, and five frameshift variants) that were potentially related to ALL risk in 35 cases (1%). 15 (48%) of 31 ALL-related ETV6 variants clustered in the erythroblast transformation specific domain and were predicted to be highly deleterious. Children with ALL-related ETV6 variants were significantly older at leukaemia diagnosis than those without (10·2 years [IQR 5·3-13·8] vs 4·7 years [3·0-8·7]; p=0·017). The hyperdiploid leukaemia karyotype was highly over-represented in ALL cases harbouring germline ETV6 risk variants compared with the wild-type group (nine [64%] of 14 cases vs 538 [27%] of 2007 cases; p=0·0050). INTERPRETATION: Our findings indicated germline ETV6 variations as the basis of a novel genetic syndrome associated with predisposition to childhood ALL. The development of recommendations for clinical interventions and surveillance for individuals harbouring ALL-related ETV6 variants are needed. FUNDING: US National Institutes of Health and American Lebanese Syrian Associated Charities.


Assuntos
Biomarcadores Tumorais/genética , Mutação em Linhagem Germinativa , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proteínas Proto-Oncogênicas c-ets/genética , Proteínas Repressoras/genética , Adolescente , Fatores Etários , Estudos de Casos e Controles , Criança , Pré-Escolar , Biologia Computacional , Análise Mutacional de DNA , Bases de Dados Genéticas , Exoma , Feminino , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Cariotipagem , Masculino , Fenótipo , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Fatores de Risco , Resultado do Tratamento
12.
J Clin Lipidol ; 9(5 Suppl): S88-92, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26343216

RESUMO

BACKGROUND: Early identification and treatment of individuals with elevated levels of atherogenic cholesterol have been shown to be effective and safe in reducing morbidity and mortality, especially in familial hypercholesterolemia. To better inform providers and identify children and adolescents at risk of premature cardiovascular disease, in November 2011, the National Heart, Lung, and Blood Institute (NHLBI) published guidelines recommending cholesterol screening of all children aged between 9 to 11 and 17 to 21 years regardless of the child's general health or the presence or the absence of cardiovascular disease risk factors. OBJECTIVE: To compare the number of 9- to 11-year-old children screened for hypercholesterolemia in 5 community-based ambulatory pediatric clinics before and after publication of the NHLBI's guidelines. METHODS: Practice demographics, screening frequency, and test results for each clinic were collected before and after publication of the NHLBI's recommendation. Provider education was provided between measures. RESULTS: Of all eligible 9- to 11-year-old children, 489 (17.1%) were screened before and 686 (20.1%) after the NHLBI's guidelines and provider education. CONCLUSIONS: Baseline rates of lipid screening for the 5 community-based ambulatory pediatric clinics were higher than those previously reported and increased significantly after publication of the NHLBI's recommendations and provider education. However, overall screening rates remained low. Given the high prevalence of premature cardiovascular disease associated with atherogenic cholesterol, especially familial hypercholesterolemia, additional strategies are needed to improve screening rates.


Assuntos
Instituições de Assistência Ambulatorial , Colesterol/sangue , Programas de Rastreamento , Pediatria , Características de Residência , Adolescente , Criança , Humanos , Lipoproteínas/sangue
13.
Int J Dev Neurosci ; 46: 92-9, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26287661

RESUMO

Chemotherapeutic regimens used for the treatment of Neuroblastoma (NB) cause long-term side effects in pediatric patients. NB arises in immature sympathetic nerve cells and primarily affects infants and children. A high rate of relapse in high-risk neuroblastoma (HRNB) necessitates the development of alternative strategies for effective treatment. This study investigated the efficacy of a small molecule, tolfenamic acid (TA), for enhancing the anti-proliferative effect of 13 cis-retinoic acid (RA) in HRNB cell lines. LA1-55n and SH-SY5Y cells were treated with TA (30µM) or RA (20µM) or both (optimized doses, derived from dose curves) for 48h and tested the effect on cell viability, apoptosis and selected molecular markers (Sp1, survivin, AKT and ERK1/2). Cell viability and caspase activity were measured using the CellTiter-Glo and Caspase-Glo kits. The apoptotic cell population was determined by flow cytometry with Annexin-V staining. The expression of Sp1, survivin, AKT, ERK1/2 and c-PARP was evaluated by Western blots. The combination therapy of TA and RA resulted in significant inhibition of cell viability (p<0.0001) when compared to individual agents. The anti-proliferative effect is accompanied by a decrease in Sp1 and survivin expression and an increase in apoptotic markers, Annexin-V positive cells, caspase 3/7 activity and c-PARP levels. Notably, TA+RA combination also caused down regulation of AKT and ERK1/2 suggesting a distinct impact on survival and proliferation pathways via signaling cascades. This study demonstrates that the TA mediated inhibition of Sp1 in combination with RA provides a novel therapeutic strategy for the effective treatment of HRNB in children.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Isotretinoína/farmacologia , Teratogênios/farmacologia , ortoaminobenzoatos/farmacologia , Análise de Variância , Anexina A5/metabolismo , Protocolos de Quimioterapia Combinada Antineoplásica , Caspases/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Citometria de Fluxo , Humanos , Neuroblastoma/patologia , Fatores de Tempo
14.
Nat Commun ; 6: 7553, 2015 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-26104880

RESUMO

There is increasing evidence from genome-wide association studies for a strong inherited genetic basis of susceptibility to acute lymphoblastic leukaemia (ALL) in children, yet the effects of protein-coding variants on ALL risk have not been systematically evaluated. Here we show a missense variant in CDKN2A associated with the development of ALL at genome-wide significance (rs3731249, P=9.4 × 10(-23), odds ratio=2.23). Functional studies indicate that this hypomorphic variant results in reduced tumour suppressor function of p16(INK4A), increases the susceptibility to leukaemic transformation of haematopoietic progenitor cells, and is preferentially retained in ALL tumour cells. Resequencing the CDKN2A-CDKN2B locus in 2,407 childhood ALL cases reveals 19 additional putative functional germline variants. These results provide direct functional evidence for the influence of inherited genetic variation on ALL risk, highlighting the important and complex roles of CDKN2A-CDKN2B tumour suppressors in leukaemogenesis.


Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Animais , Estudos de Casos e Controles , Criança , Inibidor de Quinase Dependente de Ciclina p15/genética , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Proteínas de Ligação a DNA/genética , Predisposição Genética para Doença , Variação Genética , Estudo de Associação Genômica Ampla , Genótipo , Mutação em Linhagem Germinativa , Células HEK293 , Células-Tronco Hematopoéticas/metabolismo , Humanos , Fator de Transcrição Ikaros/genética , Camundongos , Mutagênese Sítio-Dirigida , Mutação de Sentido Incorreto , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Fatores de Transcrição/genética
15.
Blood ; 126(1): 69-75, 2015 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-25987655

RESUMO

Asparaginase is used to treat acute lymphoblastic leukemia (ALL); however, hypersensitivity reactions can lead to suboptimal asparaginase exposure. Our objective was to use a genome-wide approach to identify loci associated with asparaginase hypersensitivity in children with ALL enrolled on St. Jude Children's Research Hospital (SJCRH) protocols Total XIIIA (n = 154), Total XV (n = 498), and Total XVI (n = 271), or Children's Oncology Group protocols POG 9906 (n = 222) and AALL0232 (n = 2163). Germline DNA was genotyped using the Affymetrix 500K, Affymetrix 6.0, or the Illumina Exome BeadChip array. In multivariate logistic regression, the intronic rs6021191 variant in nuclear factor of activated T cells 2 (NFATC2) had the strongest association with hypersensitivity (P = 4.1 × 10(-8); odds ratio [OR] = 3.11). RNA-seq data available from 65 SJCRH ALL tumor samples and 52 Yoruba HapMap samples showed that samples carrying the rs6021191 variant had higher NFATC2 expression compared with noncarriers (P = 1.1 × 10(-3) and 0.03, respectively). The top ranked nonsynonymous polymorphism was rs17885382 in HLA-DRB1 (P = 3.2 × 10(-6); OR = 1.63), which is in near complete linkage disequilibrium with the HLA-DRB1*07:01 allele we previously observed in a candidate gene study. The strongest risk factors for asparaginase allergy are variants within genes regulating the immune response.


Assuntos
Asparaginase/uso terapêutico , Hipersensibilidade a Drogas/genética , Fatores de Transcrição NFATC/genética , Adolescente , Adulto , Criança , Pré-Escolar , Hipersensibilidade a Drogas/epidemiologia , Terapia de Reposição de Enzimas/efeitos adversos , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Cadeias HLA-DRB1/genética , Humanos , Lactente , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adulto Jovem
16.
Lancet Oncol ; 16(4): 465-74, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25800893

RESUMO

BACKGROUND: The level of minimal residual disease during remission induction is the most important prognostic indicator in patients with acute lymphoblastic leukaemia (ALL). We aimed to establish the clinical significance of minimal residual disease in a prospective trial that used sequential minimal residual disease measurements to guide treatment decisions. METHODS: Between June 7, 2000, and Oct 24, 2007, 498 assessable patients with newly diagnosed ALL were enrolled in a clinical trial at St Jude Children's Research Hospital. We provisionally classified the risk of relapse as low, standard, or high according to patients' baseline clinical and laboratory features. Final risk assignment to establish treatment intensity was based mainly on minimal residual disease levels measured on days 19 and 46 of remission induction, and on week 7 of maintenance treatment. Additional measurements of minimal residual disease were made on weeks 17, 48, and 120 (end of treatment). The primary aim was to establish the association between event-free survival and patients' minimal residual disease levels during remission induction and sequentially post-remission. This trial was registered at ClinicalTrials.gov, number NCT00137111. FINDINGS: Irrespective of the provisional risk classification, 10-year event-free survival was significantly worse for patients with 1% or greater minimal residual disease levels on day 19 compared with patients with lower minimal residual disease levels (69·2%, 95% CI 49·6-82·4, n=36 vs 95·5%, 91·7-97·5, n=244; p<0·001 for the provisional low-risk group and 65·1%, 50·7-76·2, n=56 vs 82·9%, 75·6-88·2, n=142; p=0·01 for the provisional standard-risk group). 12 patients with provisional low-risk ALL and 1% or higher minimal residual disease levels on day 19 but negative minimal residual disease (<0·01%) on day 46 were treated for standard-risk ALL and had a 10-year event-free survival of 88·9% (43·3-98·4). For the 280 provisional low-risk patients, a minimal residual disease level of less than 1% on day 19 predicted a better outcome, irrespective of the minimal residual disease level on day 46. Of provisional standard-risk patients with minimal residual disease of less than 1% on day 19, the 15 with persistent minimal residual disease on day 46 seemed to have an inferior 10-year event-free survival compared with the 126 with negative minimal residual disease (72·7%, 42·5-88·8 vs 84·0%, 76·3-89·4; p=0·06) after receiving the same post-remission treatment for standard-risk ALL. Of patients attaining negative minimal residual disease status after remission induction, minimal residual disease re-emerged in four of 382 studied on week 7, one of 448 at week 17, and one of 437 at week 48; all but one of these six patients died despite additional treatment. By contrast, relapse occurred in only two of the 11 patients who had decreasing minimal residual disease levels between the end of induction and week 7 of maintenance therapy and were treated with chemotherapy alone. INTERPRETATION: Minimal residual disease levels during remission induction treatment have important prognostic and therapeutic implications even in the context of minimal residual disease-guided treatment. Sequential minimal residual disease monitoring after remission induction is warranted for patients with detectable minimal residual disease. FUNDING: National Institutes of Health and American Lebanese Syrian Associated Charities.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Recidiva Local de Neoplasia/tratamento farmacológico , Neoplasia Residual/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Asparaginase/administração & dosagem , Criança , Pré-Escolar , Intervalo Livre de Doença , Feminino , Humanos , Lactente , Masculino , Metotrexato/administração & dosagem , Recidiva Local de Neoplasia/patologia , Neoplasia Residual/induzido quimicamente , Neoplasia Residual/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Prednisona/administração & dosagem , Estudos Prospectivos , Indução de Remissão , Fatores de Risco , Estados Unidos , Vincristina/administração & dosagem
17.
J Clin Oncol ; 33(6): 610-5, 2015 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-25605853

RESUMO

PURPOSE: Hip osteonecrosis frequently complicates treatment with glucocorticoids. When extensive (affecting ≥ 30% of the epiphyseal surface), 80% of joints collapse within 2 years, so interventions are needed to prevent this outcome. PATIENTS AND METHODS: This prospective cohort magnetic resonance imaging (MRI) screening study included all consecutive children treated for acute lymphoblastic leukemia on a single protocol. Hip MRI was performed at 6.5 and 9 months from diagnosis (early screening) and at completion of chemotherapy (final evaluation) to determine whether screening could identify extensive hip osteonecrosis before symptom development. RESULTS: Of 498 patients, 462 underwent screening MRI. Extensive asymptomatic osteonecrosis was identified by early screening in 26 patients (41 hips); another four patients (seven hips) were detected after the screening period, such that screening sensitivity was 84.1% and specificity was 99.4%. The number of joints screened to detect one lesion was 20.1 joints for all patients, 4.4 joints for patients older than 10 years, and 198 joints for patients ≤ 10 years old (P < .001). Of the 40 extensive lesions in patients older than 10 years, 19 required total hip arthroplasty and none improved. Of eight extensive lesions in younger patients, none required arthroplasty and four improved. CONCLUSION: In patients age 10 years old or younger who require prolonged glucocorticoid therapy, screening for extensive hip osteonecrosis is unnecessary because their risk is low and lesions tend to heal. In children older than 10 years, early screening successfully identifies extensive asymptomatic lesions in patients who would be eligible for studies of interventions to prevent or delay joint collapse.


Assuntos
Necrose da Cabeça do Fêmur/induzido quimicamente , Necrose da Cabeça do Fêmur/diagnóstico , Glucocorticoides/efeitos adversos , Imagem por Ressonância Magnética/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Adolescente , Criança , Pré-Escolar , Estudos de Coortes , Humanos , Lactente , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Estudos Prospectivos
18.
Pediatr Blood Cancer ; 62(1): 123-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25176022

RESUMO

BACKGROUND: Subclinical cardiotoxicity occurs in childhood cancer survivors following moderate and high anthracycline doses. However, less is known about the subclinical changes in left ventricular (LV) structure that occur after very low anthracycline doses of ≤ 100 mg/m(2). This study was designed to assess LV function and key structural parameters following very low doses of anthracycline. PROCEDURE: Conventional 2-dimensional echocardiograms with Doppler were obtained in 91 survivors of childhood cancer exposed to ≤ 100 mg/m(2), an average of 9.8 years from diagnosis. LV structural measurements were converted into Z-scores. The Z-score distributions were compared to those of the normal population. Diastolic and systolic function were quantified. RESULTS: The cohort demonstrated a decreased posterior wall thickness (mean Z-score -1.01) and mildly decreased LV end diastolic (mean Z-score -0.85) and systolic (mean Z-score -0.84) dimensions compared to the normal population (P < 0.001). Further, 28% of patients (n = 25) had abnormal LV posterior wall thickness, ≥ 2 standard deviations below the mean (Z-score ≤ -2). There were no patients with diastolic dysfunction or symptomatic systolic dysfunction, however four patients demonstrated abnormal SF ≤ 28%. CONCLUSIONS: A significant proportion of patients exposed to very low doses of anthracycline demonstrate subclinical abnormalities in LV structure, despite the absence of radiation or other risk factors. While we cannot say whether these structural changes will result in clinically significant cardiac disease, the reported progressive nature of these findings raises concern that there may truly be no safe dose of anthracycline.


Assuntos
Antraciclinas/efeitos adversos , Antibióticos Antineoplásicos/efeitos adversos , Cardiopatias/induzido quimicamente , Cardiopatias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Sobreviventes , Função Ventricular Esquerda/efeitos dos fármacos , Adolescente , Adulto , Criança , Estudos de Coortes , Estudos Transversais , Ecocardiografia , Feminino , Seguimentos , Humanos , Masculino , Neoplasias/mortalidade , Neoplasias/patologia , Prognóstico , Fatores de Risco , Taxa de Sobrevida , Adulto Jovem
19.
Blood ; 124(8): 1266-76, 2014 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-24970932

RESUMO

Asparaginase is a therapeutic enzyme used to treat leukemia and lymphoma, with immune responses resulting in suboptimal drug exposure and a greater risk of relapse. To elucidate whether there is a genetic component to the mechanism of asparaginase-induced immune responses, we imputed human leukocyte antigen (HLA) alleles in patients of European ancestry enrolled on leukemia trials at St. Jude Children's Research Hospital (n = 541) and the Children's Oncology Group (n = 1329). We identified a higher incidence of hypersensitivity and anti-asparaginase antibodies in patients with HLA-DRB1*07:01 alleles (P = 7.5 × 10(-5), odds ratio [OR] = 1.64; P = 1.4 × 10(-5), OR = 2.92, respectively). Structural analysis revealed that high-risk amino acids were located within the binding pocket of the HLA protein, possibly affecting the interaction between asparaginase epitopes and the HLA-DRB1 protein. Using a sequence-based consensus approach, we predicted the binding affinity of HLA-DRB1 alleles for asparaginase epitopes, and patients whose HLA genetics predicted high-affinity binding had more allergy (P = 3.3 × 10(-4), OR = 1.38). Our results suggest a mechanism of allergy whereby HLA-DRB1 alleles that confer high-affinity binding to asparaginase epitopes lead to a higher frequency of reactions. These trials were registered at www.clinicaltrials.gov as NCT00137111, NCT00549848, NCT00005603, and NCT00075725.


Assuntos
Alelos , Anticorpos , Antineoplásicos/efeitos adversos , Asparaginase/efeitos adversos , Hipersensibilidade a Drogas , Cadeias HLA-DRB1 , Leucemia/tratamento farmacológico , Adolescente , Adulto , Anticorpos/sangue , Anticorpos/imunologia , Antineoplásicos/administração & dosagem , Asparaginase/administração & dosagem , Criança , Pré-Escolar , Hipersensibilidade a Drogas/sangue , Hipersensibilidade a Drogas/genética , Hipersensibilidade a Drogas/imunologia , Epitopos/sangue , Epitopos/genética , Epitopos/imunologia , Feminino , Cadeias HLA-DRB1/genética , Cadeias HLA-DRB1/imunologia , Humanos , Lactente , Leucemia/genética , Leucemia/imunologia , Leucemia/patologia , Masculino , Fatores de Risco
20.
Front Oncol ; 4: 101, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24860784

RESUMO

The two major forms of leukemia, acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML), account for about one-third of the malignancies diagnosed in children. Despite the marked successes in ALL and AML treatment, concerns remain regarding the occurrence of resistant disease in subsets of patients, the residual effects of therapy that often persist for decades beyond the cessation of treatment. Therefore, new approaches are needed to reduce or to avoid off target toxicities, associated with chemotherapy and their long-term residual effects. Recently, nanotechnology has been employed to enhance cancer therapy, via improving the bioavailability and therapeutic efficacy of anti-cancer agents. While in the last several years, numerous review articles appeared detailing the size, composition, assembly, and performance evaluation of different types of drug carrying nanoparticles, the description and evaluation of lipoprotein-based drug carriers have been conspicuously absent from most of these major reviews. The current review focuses on such information regarding nanoparticles with an emphasis on high density lipoprotein-based drug delivery systems to examine their potential role(s) in the enhanced treatment of children with leukemia.

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