Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 26
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Eur J Cancer Care (Engl) ; 21(1): 67-77, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21883563

RESUMEN

Patients with chronic lymphocytic leukaemia (CLL) find it hard to accept a diagnosis of an incurable cancer for which no treatment is recommended and which may not cause symptoms for many years. We used qualitative interviews with 12 people with CLL managed by watchful waiting, drawn from a maximum variation sample of 39 adults with leukaemia, to explore accounts of watchful waiting and implications for clinical management. Patients with CLL recalled being given little information about the condition and wanted to know more about how it might affect them in the future. The invisibility of CLL meant that some chose not to disclose the diagnosis to others. Check-ups sometimes felt cursory, causing dissatisfaction. As symptoms increased, lifestyle adaptations became essential, well before treatment was warranted. Patients with CLL on watchful waiting experience levels of depression, anxiety and quality of life similar to those in active treatment; our qualitative approach has illuminated some of the reasons for the negative psychological impacts. We relate our findings to perceptions of the illness state, doctor-patient communication, and work pressure. We recommend that specialists could better support patients by acknowledging psychological impacts of CLL, actively listening to patients' concerns, and meeting their needs for information.


Asunto(s)
Leucemia Linfocítica Crónica de Células B/psicología , Leucemia Linfocítica Crónica de Células B/terapia , Satisfacción del Paciente , Relaciones Médico-Paciente , Espera Vigilante , Adaptación Psicológica , Anciano , Anciano de 80 o más Años , Comunicación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Investigación Cualitativa , Calidad de Vida , Encuestas y Cuestionarios , Reino Unido
2.
Lancet ; 370(9583): 230-239, 2007 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-17658394

RESUMEN

BACKGROUND: Previous studies of patients with chronic lymphocytic leukaemia reported high response rates to fludarabine combined with cyclophosphamide. We aimed to establish whether this treatment combination provided greater survival benefit than did chlorambucil or fludarabine. METHODS: 777 patients with chronic lymphocytic leukaemia requiring treatment were randomly assigned to fludarabine (n=194) or fludarabine plus cyclophosphamide (196) for six courses, or chlorambucil (387) for 12 courses. The primary endpoint was overall survival, with secondary endpoints of response rates, progression-free survival, toxic effects, and quality of life. Analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number NCT 58585610. FINDINGS: There was no significant difference in overall survival between patients given fludarabine plus cyclophosphamide, fludarabine, or chlorambucil. Complete and overall response rates were better with fludarabine plus cyclophosphamide than with fludarabine (complete response rate 38%vs 15%, respectively; overall response rate 94%vs 80%, respectively; p<0.0001 for both comparisons), which were in turn better than with chlorambucil (complete response rate 7%, overall response rate 72%; p=0.006 and 0.04, respectively). Progression-free survival at 5 years was significantly better with fludarabine plus cyclophosphamide (36%) than with fludarabine (10%) or chlorambucil (10%; p<0.00005). Fludarabine plus cyclophosphamide was the best combination for all ages, including patients older than 70 years, and in prognostic groups defined by immunoglobulin heavy chain gene (V(H)) mutation status and cytogenetics, which were tested in 533 and 579 cases, respectively. Patients had more neutropenia and days in hospital with fludarabine plus cyclophosphamide, or fludarabine, than with chlorambucil. There was less haemolytic anaemia with fludarabine plus cyclophosphamide (5%) than with fludarabine (11%) or chlorambucil (12%). Quality of life was better for responders, but preliminary analyses showed no significant difference between treatments. A meta-analysis of these data and those of two published phase III trials showed a consistent benefit for the fludarabine plus cyclophosphamide regimen in terms of progression-free survival. INTERPRETATION: Fludarabine plus cyclophosphamide should now become the standard treatment for chronic lymphocytic leukaemia and the basis for new protocols that incorporate monoclonal antibodies.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Anciano , Clorambucilo/administración & dosificación , Clorambucilo/efectos adversos , Ciclofosfamida/administración & dosificación , Ciclofosfamida/efectos adversos , Supervivencia sin Enfermedad , Femenino , Humanos , Leucemia Linfocítica Crónica de Células B/mortalidad , Leucemia Linfocítica Crónica de Células B/patología , Masculino , Persona de Mediana Edad , Análisis de Supervivencia , Vidarabina/administración & dosificación , Vidarabina/efectos adversos , Vidarabina/análogos & derivados
3.
Leukemia ; 21(9): 1885-91, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17568813

RESUMEN

The management of chronic lymphocytic leukemia (CLL) has historically relied on 'watchful waiting' and palliative approaches to therapy. However, the course of disease is highly variable and a substantial proportion of patients with early-stage CLL develop rapidly progressive disease requiring therapy. In recent decades, numerous clinical and biological prognostic markers that are predictive of decreased survival outcomes, disease progression and/or resistance to therapy, and that may play a role in defining the subgroups of patients with 'high-risk' CLL have been identified. At the same time, highly effective treatment modalities have become available with the advent of chemoimmunotherapy combinations and allogeneic stem cell transplantation. Thus, we are approaching an era when patients with CLL may potentially benefit from individualized risk assessments based on prognostic markers and when specific therapies may be offered to the subgroup of patients with high-risk disease. This review provides a brief overview of newer biological prognostic markers, discusses the challenges associated with identifying the subgroup of patients with high-risk CLL and further aims to provide recommendations on how prognostic markers may be used to assess high-risk subgroups in different clinical situations in CLL.


Asunto(s)
Biomarcadores de Tumor , Inmunoterapia , Leucemia Linfocítica Crónica de Células B/epidemiología , Leucemia Linfocítica Crónica de Células B/terapia , Humanos , Pronóstico , Factores de Riesgo
4.
Leukemia ; 19(5): 741-9, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15772699

RESUMEN

Some cellular and molecular features of chronic lymphocytic leukaemia (CLL) cells that are associated with prognosis may reflect the context within which their progenitors encountered antigen. It follows that the nature of antigen drive in CLL could influence the clinical course and we were prompted to assess the impact, if any, of affinity maturation (an antigen-driven process) on prognosis. Statistical models for assessing affinity maturation status are typically applied to V(H) gene sequence data analysed using a web-based resource like IMGT or VBASE. Since these resources differ with respect to some key relevant features, we evaluated a cohort of CLL cases by applying statistical models to V(H) data derived from both IMGT and VBASE. Important differences between the resulting data sets became apparent. These resulted from database variance and because IMGT and VBASE define complementarity-determining and framework regions (CDRs, FRs) in different ways. Thus, the numbers of mutations identified and their distribution between CDRs/FRs varied between the data sets for the majority of clones. Consequently, two different but overlapping sets of cases with evidence of affinity maturation were defined. Notwithstanding their differences, no significant associations of affinity maturation status with CD38 expression, p53 functional status or survival were identifiable in either data set.


Asunto(s)
Biología Computacional , Análisis Mutacional de ADN/métodos , Bases de Datos Genéticas , Inmunogenética/estadística & datos numéricos , Fragmentos de Inmunoglobulinas/genética , Cadenas Pesadas de Inmunoglobulina/genética , Leucemia Linfocítica Crónica de Células B/genética , ADP-Ribosil Ciclasa/genética , ADP-Ribosil Ciclasa 1 , Anciano , Antígenos CD/genética , Células Clonales , Femenino , Humanos , Leucemia Linfocítica Crónica de Células B/diagnóstico , Leucemia Linfocítica Crónica de Células B/mortalidad , Masculino , Glicoproteínas de Membrana , Mutación , Pronóstico , Reproducibilidad de los Resultados , Análisis de Supervivencia , Proteína p53 Supresora de Tumor/fisiología , Interfaz Usuario-Computador
5.
Cancer Res ; 60(15): 4187-93, 2000 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-10945628

RESUMEN

Although the nucleoside analogues fludarabine and chlorodeoxyadenosine have become important therapeutic agents in chronic lymphocytic leukemia (CLL), their effectiveness is limited by drug resistance. Because such resistance is likely to result from impaired drug-induced apoptosis, it is clearly important to understand the mechanisms involved in this process. Whereas p53 can contribute to the nucleoside-induced killing of CLL cells, recent work from this laboratory and elsewhere has shown that such killing can also occur by p53-independent mechanisms. Because poly(ADP-ribose) polymerase (PARP)-mediated NAD+/ATP depletion has been implicated in the nucleoside-induced killing of normal resting lymphocytes, we postulated that this mechanism might account for the p53-independent component of nucleoside cytotoxicity in CLL. To address this question, we used 3-aminobenzamide (3AB) at a concentration (200 microM) known to produce selective inhibition of poly(ADP-ribosyl)ation in intact cells and examined nucleoside-induced killing using a number of different end points (cell membrane disruption, cell shrinkage, mitochondrial depolarization, exposure of phosphatidyl serine, morphological changes, DNA fragmentation, and PARP-1 cleavage). In 27 of the 30 cases of CLL examined, 3AB delayed nucleoside-induced cell membrane disruption without inhibiting other manifestations of cytotoxicity. This indicates that PARP activity, rather than contributing to the induction of cell killing, was accelerating cell membrane disruption during the late stages of apoptosis. This novel observation has important implications for previous studies of PARP-mediated cytotoxicity. However, in cells from one CLL patient, 3AB inhibited all manifestations of nucleoside cytotoxicity; this was the only case in the study known to have a p53 gene defect affecting both alleles. This indicates that PARP activity can occasionally be central to nucleoside-induced killing and that such PARP-mediated killing is p53 independent.


Asunto(s)
Antineoplásicos/farmacología , Cladribina/farmacología , Leucemia Linfocítica Crónica de Células B/enzimología , Poli(ADP-Ribosa) Polimerasas/metabolismo , Vidarabina/análogos & derivados , Benzamidas/farmacología , Muerte Celular/efectos de los fármacos , Muerte Celular/fisiología , Membrana Celular/efectos de los fármacos , Tamaño de la Célula/efectos de los fármacos , Fragmentación del ADN/efectos de los fármacos , Interacciones Farmacológicas , Resistencia a Antineoplásicos/fisiología , Inhibidores Enzimáticos/farmacología , Humanos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Leucemia Linfocítica Crónica de Células B/patología , Inhibidores de Poli(ADP-Ribosa) Polimerasas , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/fisiología , Vidarabina/farmacología
6.
Leuk Res ; 25(11): 1003-12, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11597735

RESUMEN

Chronic lymphocytic leukaemia (CLL) cells are long-lived in vivo but undergo spontaneous apoptosis when cultured in vitro. Since CLL cells associate intimately with one another at sites of tissue involvement, we examined the hitherto unproven possibility that homotypic interactions between the malignant cells might reduce their propensity to undergo spontaneous cell death. In a series of experiments in which highly pure CLL-cell populations were cultured on a non-adherent surface, cell viability was found to increase markedly with the level of crowding at the bottom of the culture vessel. The effect was observed among unevenly distributed cells within a single culture vessel and did not require direct cell-cell contact. This indicates that cell survival was being regulated in an autocrine fashion by locally acting soluble products. Conditioned medium from crowded CLL cells enhanced the survival of autologous non-crowded cells, indicating that at least some of the autocrine survival factors produced by CLL cells could accumulate in the extracellular environment. In addition, the survival of non-crowded CLL cells was markedly enhanced by co-culturing them with an excess of autologous fixed cells. This protective effect of direct cell-cell contact was mediated by specific surface structures since it was abrogated by pre-treating the fixed cells with neuraminidase. Our results provide the first direct demonstration that the survival of cultured CLL cells is enhanced by homotypic interactions. We speculate that these protective effects may contribute to the accumulation of CLL cells in vivo, and that further elucidation of the underlying mechanisms may lead to novel therapeutic strategies.


Asunto(s)
Comunicación Celular , Leucemia Linfocítica Crónica de Células B/patología , Antígenos CD19/metabolismo , Antígenos CD19/fisiología , Comunicación Autocrina , Antígenos CD5/metabolismo , Antígenos CD5/fisiología , Supervivencia Celular/efectos de los fármacos , Endopeptidasas/metabolismo , Humanos , Mapeo Peptídico , Receptores de IgE/metabolismo , Receptores de IgE/fisiología
7.
Bone Marrow Transplant ; 14(4): 495-504, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7858524

RESUMEN

Thrombotic microangiopathy (TMA) is a well-recognised disorder which may occur in up to 6% of patients following bone marrow transplantation (BMT). Reported cases of post-BMT TMA vary widely in their reported clinical features, severity and response to therapy. Several factors are important in the aetiology, including cyclosporin A (CsA), graft-versus-host disease, irradiation, intensive conditioning chemotherapy and infection. A unifying pathogenetic mechanism is suggested, wherein these factors may interact to produce post-BMT TMA. On the basis of differences in clinical features and prognosis, we propose the classification of post-BMT TMA into four distinctive although overlapping subtypes: multifactorial fulminant TMA, conditioning-associated haemolytic-uraemic syndrome, CsA-associated nephrotoxicity with microangiopathic haemolytic anaemia (MAHA) and CsA-associated neurotoxicity with MAHA. Treatment of post-BMT TMA, especially of the poor-prognosis multifactorial fulminant subtype, is currently unsatisfactory, although occasional cases may respond to plasma exchange.


Asunto(s)
Anemia Hemolítica/etiología , Trasplante de Médula Ósea/efectos adversos , Síndrome Hemolítico-Urémico/etiología , Púrpura Trombocitopénica Trombótica/etiología , Ciclosporina/efectos adversos , Endotelio Vascular/efectos de los fármacos , Enfermedad Injerto contra Huésped/complicaciones , Humanos
8.
Bone Marrow Transplant ; 13(2): 225-7, 1994 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8205096

RESUMEN

Vogt-Koyanagi-Harada (VKH) syndrome is an uncommon acute ophthalmological disorder, characterised by bilateral serous retinal detachment with diffuse choroiditis, in association with specific extra-ocular manifestations. We describe a patient with unequivocal VKH syndrome arising 49 days after matched unrelated donor bone marrow transplantation (BMT) performed as treatment for severe aplastic anaemia. The visual symptoms and retinal changes responded well to corticosteroids. The haematological relevance of VKH syndrome is to distinguish it from retinitis due to cytomegalovirus, which requires different therapy and has a far worse visual prognosis.


Asunto(s)
Trasplante de Médula Ósea/efectos adversos , Síndrome Uveomeningoencefálico/etiología , Adulto , Anemia Aplásica/terapia , Humanos , Incidencia , Masculino , Síndrome Uveomeningoencefálico/diagnóstico , Síndrome Uveomeningoencefálico/epidemiología
9.
Bone Marrow Transplant ; 49(2): 280-6, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24212561

RESUMEN

EBV-associated post-transplant lymphoproliferative disease (PTLD) following Alemtuzumab-based allo-SCT is a relatively uncommon and challenging clinical problem but has not received detailed study in a large cohort. Quantitative-PCR (qPCR) monitoring for EBV reactivation post allo-SCT is now commonplace but its diagnostic and predictive value remains unclear. Sixty-nine patients with PTLD following Alemtuzumab-based allo-SCT were studied. Marked clinicopathological heterogeneity was evident; lymphadenopathy was frequently absent, whereas advanced extranodal disease was common. The median viral load at clinical presentation was 49 300 copies/mL (50-65 200 000 copies/mL) and, notably, 23% and 45% of cases, respectively, had 10 000 and 40 000 copies/mL. The overall response rate to rituximab as first-line therapy was 70%. For rituximab failures, chemotherapy was ineffectual but DLIs were successful. A four-parameter prognostic index predicted response to therapy (OR 0.30 (0.12-0.74); P=0.009] and PTLD mortality (hazard ratio (HR) 1.81 (1.12-2.93) P=0.02) on multivariate analysis. This is the largest detailed series of EBV-associated PTLD after allo-SCT. At clinical presentation, EBV-qPCR values are frequently below customary thresholds for pre-emptive therapy, challenging current paradigms for monitoring and intervention. A four-point score identifies a proportion of patients at risk of rituximab-refractory disease for whom alternative therapy is needed.


Asunto(s)
Anticuerpos Monoclonales de Origen Murino/uso terapéutico , Antineoplásicos/uso terapéutico , Infecciones por Virus de Epstein-Barr/etiología , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Trastornos Linfoproliferativos/virología , Acondicionamiento Pretrasplante/efectos adversos , Adulto , Anticuerpos Monoclonales de Origen Murino/administración & dosificación , Anticuerpos Monoclonales de Origen Murino/farmacología , Antineoplásicos/administración & dosificación , Antineoplásicos/farmacología , Estudios de Cohortes , Infecciones por Virus de Epstein-Barr/tratamiento farmacológico , Femenino , Trasplante de Células Madre Hematopoyéticas/métodos , Humanos , Inmunoterapia , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Rituximab , Análisis de Supervivencia , Acondicionamiento Pretrasplante/métodos , Carga Viral
10.
Leukemia ; 27(1): 142-9, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23041722

RESUMEN

Detection of minimal residual disease (MRD) in chronic lymphocytic leukaemia (CLL) is becoming increasingly important as treatments improve. An internationally harmonised four-colour (CLR) flow cytometry MRD assay is widely used but has limitations. The aim of this study was to improve MRD analysis by identifying situations where a less time-consuming CD19/CD5/κ/λ analysis would be sufficient for detecting residual CLL, and develop a six-CLR antibody panel that is more efficient for cases requiring full MRD analysis. In 784 samples from CLL patients after treatment, it was possible to determine CD19/CD5/κ/λ thresholds that identified cases with detectable MRD with 100% positive predictive value (PPV). However, CD19/CD5/κ/λ analysis was unsuitable for predicting iwCLL/NCI response status or identifying cases with no detectable MRD. For the latter cases requiring a full MRD assessment, a six-CLR assay was designed comprising CD19/CD5/CD20 with (1) CD3/CD38/CD79b and (2) CD81/CD22/CD43. There was good correlation between four-CLR and six-CLR panels in dilution studies and clinical samples, with 100% concordance for detection of residual disease at the 0.01% (10(-4)) level (n=59) and good linearity even at the 0.001-0.01% (10(-5)-10(-4)) level. A six-CLR panel therefore provides equivalent results to the four-CLR panel but it requires fewer reagents, fewer cells and a much simpler analysis approach.


Asunto(s)
Biomarcadores de Tumor/análisis , Citometría de Flujo/normas , Leucemia Linfocítica Crónica de Células B/patología , Neoplasia Residual/diagnóstico , Antígenos CD/análisis , Europa (Continente) , Humanos , Cadenas Ligeras de Inmunoglobulina/inmunología , Cadenas kappa de Inmunoglobulina/inmunología , Cadenas lambda de Inmunoglobulina/inmunología , Inmunofenotipificación , Leucemia Linfocítica Crónica de Células B/inmunología , Estadificación de Neoplasias , Neoplasia Residual/inmunología , Pronóstico , Sensibilidad y Especificidad
13.
Cell Death Dis ; 3: e372, 2012 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-22898870

RESUMEN

Glucocorticoids (GCs) represent an important component of modern treatment regimens for fludarabine-refractory or TP53-defective chronic lymphocytic leukemia (CLL). However, GC therapy is not effective in all patients. The molecular mechanisms responsible for GC-induced apoptosis and resistance were therefore investigated in primary malignant cells obtained from a cohort of 46 patients with CLL. Dexamethasone-induced apoptosis was unaffected by p53 dysfunction and more pronounced in cases with unmutated IGHV genes. Cross-resistance was observed between dexamethasone and other GCs but not fludarabine, indicating non-identical resistance mechanisms. GC treatment resulted in the upregulation of Bim mRNA and protein, but to comparable levels in both GC-resistant and sensitive cells. Pre-incubation with Bim siRNAs reduced GC-induced upregulation of Bim protein and conferred resistance to GC-induced apoptosis in previously GC-sensitive cells. GC-induced upregulation of Bim was associated with the activation of Bax and Bak in GC-sensitive but not -resistant CLL samples. Co-immunoprecipitation experiments showed that Bim does not interact directly with Bax or Bak, but is almost exclusively bound to Bcl-2 regardless of GC treatment. Taken together, these findings suggest that the GC-induced killing of CLL cells results from the indirect activation of Bax and Bak by upregulated Bim/Bcl-2 complexes, and that GC resistance results from the failure of such activation to occur.


Asunto(s)
Proteínas Reguladoras de la Apoptosis/metabolismo , Glucocorticoides/farmacología , Leucemia Linfocítica Crónica de Células B/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Proteína Destructora del Antagonista Homólogo bcl-2/metabolismo , Proteína X Asociada a bcl-2/metabolismo , Anciano , Antineoplásicos/uso terapéutico , Antineoplásicos/toxicidad , Apoptosis/efectos de los fármacos , Proteínas Reguladoras de la Apoptosis/antagonistas & inhibidores , Proteínas Reguladoras de la Apoptosis/genética , Proteína 11 Similar a Bcl2 , Dexametasona/farmacología , Resistencia a Antineoplásicos/efectos de los fármacos , Femenino , Humanos , Inmunoprecipitación , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Leucemia Linfocítica Crónica de Células B/patología , Masculino , Proteínas de la Membrana/antagonistas & inhibidores , Proteínas de la Membrana/genética , Persona de Mediana Edad , FN-kappa B/metabolismo , Unión Proteica , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/genética , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Vidarabina/análogos & derivados , Vidarabina/uso terapéutico , Vidarabina/toxicidad
14.
Leukemia ; 26(7): 1564-75, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22258401

RESUMEN

Genome-wide array approaches and sequencing analyses are powerful tools for identifying genetic aberrations in cancers, including leukemias and lymphomas. However, the clinical and biological significance of such aberrations and their subclonal distribution are poorly understood. Here, we present the first genome-wide array based study of pre-treatment and relapse samples from patients with B-cell chronic lymphocytic leukemia (B-CLL) that uses the computational statistical tool OncoSNP. We show that quantification of the proportion of copy number alterations (CNAs) and copy neutral loss of heterozygosity regions (cnLOHs) in each sample is feasible. Furthermore, we (i) reveal complex changes in the subclonal architecture of paired samples at relapse compared with pre-treatment, (ii) provide evidence supporting an association between increased genomic complexity and poor clinical outcome (iii) report previously undefined, recurrent CNA/cnLOH regions that expand or newly occur at relapse and therefore might harbor candidate driver genes of relapse and/or chemotherapy resistance. Our findings are likely to impact on future therapeutic strategies aimed towards selecting effective and individually tailored targeted therapies.


Asunto(s)
Biomarcadores de Tumor/genética , Aberraciones Cromosómicas , Células Clonales/patología , Leucemia Linfocítica Crónica de Células B/genética , Recurrencia Local de Neoplasia/genética , Polimorfismo de Nucleótido Simple/genética , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Dosificación de Gen , Genoma Humano , Genómica , Humanos , Leucemia Linfocítica Crónica de Células B/terapia , Pérdida de Heterocigocidad , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/terapia , Análisis de Secuencia por Matrices de Oligonucleótidos , Pronóstico
16.
Oncogene ; 27(17): 2445-55, 2008 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-17982489

RESUMEN

In chronic lymphocytic leukaemia (CLL), mutation/deletion of TP53 is strongly associated with early disease progression, resistance to chemotherapy and short patient survival. Consequently, there is a pressing need to develop novel treatment protocols for this high-risk patient group. The present study was performed to evaluate Hsp90 inhibition as a possible therapeutic approach for such patients. Primary CLL cells of defined ataxia telangiectasia mutated (ATM)/p53 status were incubated with the Hsp90 inhibitor geldanamycin (GA) and analysed by western blotting for the expression of p53, p21, MDM2 and Akt. GA downregulated overexpressed mutant p53 protein (an oncogene) and upregulated wild-type (wt) p53 (a tumour suppressor). The upregulation of wt p53 by GA was independent of ATM and was accompanied by downregulation of Akt and the active form of MDM2, indicating a possible mechanism. GA also produced a p53/ATM-independent increase in the levels of p21-a potent inducer of cell-cycle arrest. In-vitro cytotoxicity studies showed that GA killed cultured CLL cells in a dose- and time-dependent fashion irrespective of their p53/ATM status and more effectively than normal blood mononuclear cells. In summary, our findings reveal important consequences of inhibiting Hsp90 in CLL cells and strongly support the therapeutic evaluation of Hsp90 inhibitors in poor-prognosis patients with p53 defects.


Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Proteínas de Unión al ADN/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Leucemia Linfocítica Crónica de Células B/metabolismo , Proteínas Mutantes/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Proteínas de la Ataxia Telangiectasia Mutada , Benzoquinonas/toxicidad , Supervivencia Celular/efectos de los fármacos , Proteínas HSP90 de Choque Térmico/metabolismo , Humanos , Cinética , Lactamas Macrocíclicas/toxicidad , Leucemia Linfocítica Crónica de Células B/genética , Leucemia Linfocítica Crónica de Células B/patología , Proteínas Mutantes/genética , Mutación/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Transducción de Señal/efectos de los fármacos , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/genética
18.
Br J Haematol ; 109(4): 800-4, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10929033

RESUMEN

Caspases are known to be involved in the apoptotic killing of chronic lymphocytic leukaemia (CLL) cells by fludarabine. However, it is unclear whether these enzymes are required for the induction of such killing, or whether they simply determine the mode of cell death. To address this question, we examined the effect of the broad-spectrum caspase inhibitor Z-VAD.fmk on six different manifestations of nucleoside cytotoxicity. Our results indicate that while caspase activity is required for nucleoside-induced poly(ADP-ribose) polymerase (PARP) cleavage and DNA fragmentation, other manifestations of cell death (mitochondrial depolarization, exposure of phosphatidyl serine, cell membrane disruption and cell shrinkage) are caspase independent. By showing that caspases influence the mode, but not the extent, of nucleoside cytotoxicity, our results exclude defects in these enzymes as a mechanism of nucleoside resistance in CLL.


Asunto(s)
Clorometilcetonas de Aminoácidos/farmacología , Caspasas/fisiología , Inhibidores Enzimáticos/farmacología , Leucemia Linfocítica Crónica de Células B/fisiopatología , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Inhibidores de Caspasas , Membrana Celular/patología , Tamaño de la Célula , Células Cultivadas , Humanos , Leucemia Linfocítica Crónica de Células B/patología , Vidarabina/análogos & derivados , Vidarabina/farmacología
19.
Clin Lab Haematol ; 17(2): 125-9, 1995 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8536414

RESUMEN

The Coulter VCS is an automated differential counter, which derives a five-part differential count on the basis of differences in cell volume, high frequency conductivity and light scatter. A printed scatterplot relating volume and scatter is readily obtained. Other instruments which use automated cytochemistry can distinguish between AML and ALL, and between AML variants. It was our impression that the Coulter VCS might also be capable of such distinction on the basis of the scatterplot patterns. We therefore collected scatterplots produced by Coulter VCS analysis of peripheral blood from 63 patients presenting with acute leukaemia. The scatterplots were inspected and six basic patterns identified. The scatterplots were inspected and six basic patterns identified. The scatterplots could be reproducibly sorted into pattern-specific groups without knowledge of the diagnosis. Precise leukaemic diagnoses were made routinely by conventional morphology, cytochemistry and immunophenotyping. A comparison was then made with the scatterplot patterns. The 51 cases of AML produced examples of all six patterns. The nine cases of ALL produced only three patterns. These were shared with cases of AML, and two were also shared with the three cases of acute mixed lineage leukaemia. Thus, three of the six patterns were specific for AML, whereas no pattern was specific for ALL or acute mixed lineage acute leukaemia. One pattern was produced only by the three cases of AML M6, and another was produced only by five of the 25 cases of primitive (M0 and M1) AML.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Leucemia/diagnóstico , Recuento de Leucocitos/métodos , Enfermedad Aguda , Automatización , Humanos , Leucemia/sangre , Recuento de Leucocitos/instrumentación
20.
Br J Haematol ; 106(4): 1049-51, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10520012

RESUMEN

To clarify the role of p53 in the killing of chronic lymphocytic leukaemia (CLL) cells by purine analogues, we examined the cytotoxic effects of chlorodeoxyadenosine and fludarabine on CLL cells that had been characterized according to their p53 functional status. Cases of CLL with p53 dysfunction (n = 7) displayed slight, but significant, resistance to nucleoside-induced cell killing when compared with cases with functionally intact p53 (n = 12). The small difference between the two groups indicated that p53 plays a minor role in such killing. These findings suggest that the poor therapeutic response to purine analogues observed in patients with p53 defects is likely to be caused by the emergence, on a background of genomic instability, of CLL-cell clones that are resistant to nucleoside-induced killing for reasons unrelated to p53.


Asunto(s)
Antineoplásicos/uso terapéutico , Cladribina/uso terapéutico , Genes p53/genética , Leucemia Linfocítica Crónica de Células B/genética , Vidarabina/análogos & derivados , Supervivencia Celular , Humanos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Células Tumorales Cultivadas , Vidarabina/uso terapéutico
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA