RESUMEN
Early T-cell Precursor Acute Lymphoblastic Leukemia (ETP-ALL), T-Lymphoid/Myeloid Mixed Phenotype Acute Leukemia (T/M-MPAL), and Acute Myeloid Leukemia with minimal differentiation (AML-M0) are immature acute leukemias (AL) that present overlapping T-cell lymphoid and myeloid features at different degrees, with impact to disease classification. An interesting strategy to assess lymphoid lineage commitment and maturation is the analysis of V(D)J gene segment recombination, which can be applied to investigate leukemic cells in immature AL. Herein, we revisited 19 ETP-ALL, 8 T/M-MPAL, and 12 AML-M0 pediatric patients to characterize V(D)J rearrangement (V(D)J-r) profiles associated with other somatic alterations. V(D)J-r were identified in 74â¯%, 25â¯%, and 25â¯% of ETP-ALL, T/M-MPAL, and AML-M0, respectively. Forty-six percent of ETP-ALL harbored ≥â¯3 V(D)J-r, while there was no more than one V(D)J-r per patient in AML-M0 and T/M-MPAL. TCRD was the most rearranged locus in ETPALL, but it was not rearranged in other AL. In ETP-ALL, N/KRAS mutations were associated with absence of V(D)J-r, while NF1 deletion was most frequent in patients with ≥â¯3 V(D)J-r. Relapse and death occurred mainly in patients harboring one or no rearranged locus. Molecular characterization of V(D)J-r in our cohort indicates a distinct profile of ETP-ALL, compared to T/M-MPAL and AML-M0. Our findings also suggest that the clinical outcome of ETP-ALL patients may be affected by blast cell maturity, inferred from the number of rearranged TCR loci.
Asunto(s)
Leucemia Mieloide Aguda , Humanos , Niño , Preescolar , Masculino , Adolescente , Femenino , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patología , Recombinación V(D)J/genética , Lactante , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patología , Mutación , Reordenamiento GénicoAsunto(s)
Leucemia Mielógena Crónica BCR-ABL Positiva , Aprendizaje Automático Supervisado , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/diagnóstico , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , PronósticoRESUMEN
RIC-8B é uma proteína que apresenta, in vitro, atividade de fator de troca de nucleotídeos guanina (GEF). No entanto, seu papel in vivo não é conhecido. Dados anteriores do nosso laboratório demonstraram que essa proteína interage especificamente com Gαolf, que é uma proteína G exclusiva do sistema olfatório, presente nos cílios dos neurônios olfatórios, onde ocorre a transdução de sinal ativada pelos odorantes. No camundongo adulto verificou-se, por meio de ensaios de hibridização in situ, que RIC-8B está presente somente em regiões de expressão de Gαolf: no epitélio olfatório maduro e no núcleo estriado do sistema nervoso central. Para avaliar a função fisiológica de RIC-8B in vivo, resolvemos gerar uma linhagem de camundongo knockout para Ric-8B. Verificamos que a linhagem é inviável devido à letalidade dos embriões já em fases precoces do desenvolvimento (por volta de E8,5 e E9,0). A coloração de embriões com X-gal mostra que RIC-8B é especificamente expressa em regiões que darão origem ao sistema nervoso, como na região ventral do tubo neural, e em regiões cefálicas. Interessantemente, mostramos que RIC-8B é expressa na placa do assoalho do tubo neural, de uma maneira muito semelhante ao padrão de expressão de Sonic Hedgehog (SHH), que apresenta um papel fundamental para a organização do sistema nervoso, entre outras funções. Nossos resultados indicam, portanto, que RIC-8B desempenha um papel crucial durante a embriogênese, e que este papel pode estar relacionado com o papel exercido por SHH. Além disso, como a via de sinalização de SHH ocorre em cílios primários nas células alvo, nossos dados levantam a interessante possibilidade de que RIC-8B apresenta funções relacionadas a cílios, tanto no camundongo adulto (neste caso nos cílios dos neurônios olfatórios) como no embrião (neste caso nos cílios primários)
RIC-8B is a protein that, in vitro, acts as a guanine nucleotide exchange factor (GEF). However, its role in vivo remains unknown. Previous data from our laboratory demonstrated that this protein is able to interact specifically with Gαolf, a G protein found only in the olfactory system. This G protein is located in the cilia from olfactory neurons, where odorant signaling occurs. In situ hybridization experiments showed that RIC-8B, in adult mice, is expressed only in regions where Gαolf is expressed, such as the olfactory epithelium and the nucleus striatum in the central nervous system. In order to determine the function of RIC-8B in vivo, we decided to generate a knockout mouse strain for Ric-8B. We found that this strain is not viable due to the lethality of embryos in the early stages of development (around days E8.5 and E9.0). X-gal staining of embryos shows that RIC-8B is specifically expressed in regions that originate the nervous system, such as the ventral neural tube and also cephalic regions. Interestingly, we show that RIC-8B is restrictedly expressed in the floor plate of the neural tube, in a pattern that is very similar to the one shown by Sonic Hedgehog (SHH). The SHH protein plays a fundamental role in the organization of the nervous system, among other functions. Therefore, our results indicate that RIC-8B plays an essential role during the embryogenesis, and that this role can be related to the role played by SHH. Furthermore, because the SHH signaling pathway occurs in primary cilia in the target cells, our data raise the interesting possibility that the role played by RIC-8B is related to ciliary functions, both in adult mice (in this case, in olfactory cilia), and in the embryo (in this case, in primary cilia)