Asunto(s)
Mercaptopurina , Leucemia-Linfoma Linfoblástico de Células Precursoras , Alelos , Niño , Humanos , Mercaptopurina/efectos adversos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Pirofosfatasas/genética , Estudios RetrospectivosRESUMEN
Acute erythroid leukemia (AEL) is a high-risk leukemia of poorly understood genetic basis, with controversy regarding diagnosis in the spectrum of myelodysplasia and myeloid leukemia. We compared genomic features of 159 childhood and adult AEL cases with non-AEL myeloid disorders and defined five age-related subgroups with distinct transcriptional profiles: adult, TP53 mutated; NPM1 mutated; KMT2A mutated/rearranged; adult, DDX41 mutated; and pediatric, NUP98 rearranged. Genomic features influenced outcome, with NPM1 mutations and HOXB9 overexpression being associated with a favorable prognosis and TP53, FLT3 or RB1 alterations associated with poor survival. Targetable signaling mutations were present in 45% of cases and included recurrent mutations of ALK and NTRK1, the latter of which drives erythroid leukemogenesis sensitive to TRK inhibition. This genomic landscape of AEL provides the framework for accurate diagnosis and risk stratification of this disease, and the rationale for testing targeted therapies in this high-risk leukemia.
Asunto(s)
Leucemia Eritroblástica Aguda/genética , Adolescente , Adulto , Niño , Preescolar , Femenino , Genómica/métodos , Proteínas de Homeodominio/genética , Humanos , Lactante , Recién Nacido , Masculino , Mutación/genética , Proteína de la Leucemia Mieloide-Linfoide/genética , Proteínas Nucleares/genética , Nucleofosmina , Pronóstico , Proteína p53 Supresora de Tumor/genética , Adulto Joven , Tirosina Quinasa 3 Similar a fms/genéticaRESUMEN
Acute lymphoblastic leukaemia (ALL) is the most common paediatric malignancy. Although 90% of patients are now long-term survivors, the remaining 10% have poor outcome predominantly due to drug resistance. In this study, we carried out genome-wide microRNA (miRNA) microarray analysis on diagnostic bone marrow samples to determine miRNA expression profiles associated with poor outcome in ALL. A reduced expression of MIR335 was identified as the most significant miRNA abnormality associated with poor outcome. It is well known that glucocorticoid (GC) resistance is one of the major reasons contributing to poor outcome. We show that exogenous expression of MIR335 in ALL cells increases sensitization to prednisolone-mediated apoptosis. Moreover, we demonstrate that MAPK1 is a novel target of MIR335, and that MEK/ERK inhibitor treatment enhanced prednisolone-induced cell death through the activation of BIM (BCL2L11). These results provide a possible underlying molecular mechanism to explain the association between reduced MIR335 with poor clinical outcome, and suggest that approaches to re-introduce MIR335 expression or override MAPK1 activity may offer promising therapeutic strategies in the treatment of ALL.
Asunto(s)
MicroARNs/genética , Proteína Quinasa 1 Activada por Mitógenos/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidad , Línea Celular Tumoral , Niño , Preescolar , Biología Computacional/métodos , Resistencia a Antineoplásicos/genética , Femenino , Expresión Génica , Perfilación de la Expresión Génica , Regulación Leucémica de la Expresión Génica , Vectores Genéticos/genética , Humanos , Lentivirus/genética , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Masculino , Proteína Quinasa 1 Activada por Mitógenos/antagonistas & inhibidores , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Prednisolona/farmacología , Prednisolona/uso terapéutico , Pronóstico , RecurrenciaRESUMEN
BACKGROUND: Beta-thalassemia is endemic to many regions in Southeast Asia and India, and <20 beta-globin gene mutations account for > or =90% of beta-thalassemia alleles in these places. We describe a multiplex minisequencing assay to detect these common mutations. METHODS: Gap-PCR was used to simultaneously amplify the beta-globin gene from genomic DNA and to detect the Delta619bp deletion mutation. Multiplex minisequencing was then performed on the amplified beta-globin fragment to detect an additional 15 common Southeast Asian and Indian beta-thalassemia mutations. Site-specific primers of different lengths were subjected to multiple rounds of annealing and single-nucleotide extension in the presence of thermostable DNA polymerase and the four dideoxynucleotides, each labeled with a different fluorophore. Minisequencing products were separated and detected by capillary electrophoresis, followed by automated genotyping. The optimized assay was subjected to a double-blind validation analysis of 89 beta-thalassemia and wild-type DNA samples of known genotype. RESULTS: Homozygous wild-type or mutant DNA samples produced electropherograms containing only a single colored peak for each mutation site, whereas samples heterozygous for a specific mutation displayed two different-colored peaks for that mutation site. Samples were automatically genotyped based on color and position of primer peaks in the electropherogram. In the double-blind validation analysis, all 89 DNA samples were genotyped correctly (100% assay specificity). CONCLUSIONS: The described semiautomated multiplex minisequencing assay can detect the most common Southeast Asian and Indian beta-thalassemia mutations, is amenable to high-throughput scale up, and may bring population-based screening of beta-thalassemia in endemic regions a step closer to implementation.
