Asunto(s)
Antineoplásicos/uso terapéutico , Proteínas de Fusión bcr-abl/genética , Trasplante de Células Madre Hematopoyéticas , Mesilato de Imatinib/uso terapéutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Adulto , Anciano , Proteínas de Fusión bcr-abl/metabolismo , Expresión Génica , Perfilación de la Expresión Génica , N-Metiltransferasa de Histona-Lisina/genética , N-Metiltransferasa de Histona-Lisina/metabolismo , Humanos , Factor de Transcripción Ikaros/genética , Factor de Transcripción Ikaros/metabolismo , Persona de Mediana Edad , Mutación , Proteína de la Leucemia Mieloide-Linfoide/genética , Proteína de la Leucemia Mieloide-Linfoide/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidad , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Inhibidores de Proteínas Quinasas/uso terapéutico , Recurrencia , Inducción de Remisión , Análisis de Supervivencia , Trasplante HomólogoRESUMEN
This study investigated Polo-like kinase 1, a mitotic regulator often over-expressed in solid tumors and adult hematopoietic malignancies, as a potential new target in the treatment of pediatric acute lymphoblastic leukemia. Polo-like kinase 1 protein and Thr210 phosphorylation levels were higher in pediatric acute lymphoblastic leukemia (n=172) than in normal bone marrow mononuclear cells (n=10) (P<0.0001). High Polo-like kinase 1 protein phosphorylation, but not expression, was associated with a lower probability of event-free survival (P=0.042) and was a borderline significant prognostic factor (P=0.065) in a multivariate analysis including age and initial white blood cell count. Polo-like kinase 1 was necessary for leukemic cell survival, since short hairpin-mediated Polo-like kinase 1 knockdown in acute lymphoblastic leukemia cell lines inhibited cell proliferation by G2/M cell cycle arrest and induced apoptosis through caspase-3 and poly (ADP-ribose) polymerase cleavage. Primary patient cells with a high Polo-like kinase 1 protein expression were sensitive to the Polo-like kinase 1-specific inhibitor NMS-P937 in vitro, whereas cells with a low expression and normal bone marrow cells were resistant. This sensitivity was likely not caused by Polo-like kinase 1 mutations, since only one new mutation (Ser335Arg) was found by 454-sequencing of 38 pediatric acute lymphoblastic leukemia cases. This mutation did not affect Polo-like kinase 1 expression or NMS-P937 sensitivity. Together, these results indicate a pivotal role for Polo-like kinase 1 in pediatric acute lymphoblastic leukemia and show potential for Polo-like kinase 1-inhibiting drugs as an addition to current treatment strategies for cases expressing high Polo-like kinase 1 levels.
Asunto(s)
Apoptosis/efectos de los fármacos , Proteínas de Ciclo Celular/antagonistas & inhibidores , Proliferación Celular/efectos de los fármacos , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Pirazoles/farmacología , Quinazolinas/farmacología , Apoptosis/genética , Proteínas de Ciclo Celular/genética , Línea Celular Tumoral , Niño , Estudios de Cohortes , Técnicas de Silenciamiento del Gen/métodos , Células HEK293 , Humanos , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proteínas Serina-Treonina Quinasas/genética , Proteínas Proto-Oncogénicas/genética , Quinasa Tipo Polo 1RESUMEN
Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterised by the development of hamartomas in a variety of organs and tissues. The disease is caused by mutations in either the TSC1 gene on chromosome 9q34, or the TSC2 gene on chromosome 16p13.3. The TSC1 and TSC2 gene products, TSC1 and TSC2, interact to form a protein complex that inhibits signal transduction to the downstream effectors of the target of rapamycin complex 1 (TORC1). Here we investigate TSC1 structure and function by analysing a series of truncated TSC1 proteins. We identify specific regions of the protein that are important for TSC1 stability, localisation, interactions and function.
Asunto(s)
Eliminación de Gen , Multimerización de Proteína/genética , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Células Cultivadas , Inestabilidad Genómica , Humanos , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Proteínas Mutantes/fisiología , Unión Proteica/genética , Mapeo de Interacción de Proteínas , Estabilidad Proteica , Estructura Terciaria de Proteína/genética , Estructura Terciaria de Proteína/fisiología , Relación Estructura-Actividad , Proteína 1 del Complejo de la Esclerosis Tuberosa , Proteína 2 del Complejo de la Esclerosis Tuberosa , Proteínas Supresoras de Tumor/químicaRESUMEN
Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterised by the development of hamartomas in a variety of organs and tissues. The disease is caused by mutations in either the TSC1 gene on chromosome 9q34 or the TSC2 gene on chromosome 16p13.3. The TSC1 and TSC2 gene products, TSC1 and TSC2, interact to form a protein complex that inhibits signal transduction to the downstream effectors of the mammalian target of rapamycin (mTOR). Here we investigate the effects of putative TSC1 missense mutations identified in individuals with signs and/or symptoms of TSC on TSC1-TSC2 complex formation and mTOR signalling. We show that specific amino-acid substitutions close to the N-terminal of TSC1 reduce steady-state levels of TSC1, resulting in the activation of mTOR signalling and leading to the symptoms of TSC.