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1.
BMC Med Educ ; 24(1): 279, 2024 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-38494509

RESUMEN

BACKGROUND: The desire to die can occur in palliative care patients with a prevalence of up to 22%. Not every desire to die is accompanied by a pressure to act, but usually by a burden that can arise from various factors. To address this burden appropriately, health care workers should be trained. Based on an evaluated course on handling the desire to die, an elective course for medical students was developed and evaluated. In order to identify the impact of the elective course's content, a comparison of attitudes towards assisted dying with two other participant groups was conducted. Therefore, three questions from the evaluation of the elective course were used. METHOD: Online evaluation of the elective and questions addressing attitude were assessed using a five-point Likert scale. The specific outcome-based assessment was determined using the Comparative Self-Assessment Gain. The main participant group (group 1) were students who took the elective. The additional survey on attitudes towards assisted dying included undergraduate medical students who had taken compulsory palliative care courses (group 2) and physicians who had taken an introductory course in intensive care or emergency medicine (group 3). RESULTS: Group 1 (n = 13, response rate rr = 86.7%) was very satisfied with the blended learning format (100%) and the course itself (100%). They were able to deepen their knowledge (81.0%) and train skills (71.2%) through the course. In the additional surveys, there were 37 students in group 2 (rr = 66.1%) and 258 physicians in group 3 (rr = 73.6%). Willingness to assist with or accompany the various options for assisted dying varied according to the type of assistance. Among the participants, it can be summarised that the highest willingness was shown by the students of group 2 followed by the physicians of group 3 and the students of group 1. CONCLUSIONS: A course on handling the desire to die of palliative patients can deepen knowledge and train communication skills and thus support self-confidence. Dealing with the background of the desire to die, knowledge about assisted dying, but also one's own attitudes and responsibilities can influence the attitude towards assisted dying.


Asunto(s)
Medicina de Emergencia , Estudiantes de Medicina , Humanos , Cuidados Críticos , Personal de Salud , Conocimiento
3.
Leukemia ; 32(1): 92-101, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-28659618

RESUMEN

Classical Hodgkin lymphoma (cHL) and anaplastic large cell lymphoma (ALCL) feature high expression of activator protein-1 (AP-1) transcription factors, which regulate various physiological processes but also promote lymphomagenesis. The AP-1 factor basic leucine zipper transcription factor, ATF-like 3 (BATF3), is highly transcribed in cHL and ALCL; however, its functional importance in lymphomagenesis is unknown. Here we show that proto-typical CD30+ lymphomas, namely cHL (21/30) and primary mediastinal B-cell lymphoma (8/9), but also CD30+ diffuse large B-cell lymphoma (15/20) frequently express BATF3 protein. Mass spectrometry and co-immunoprecipitation established interactions of BATF3 with JUN and JUNB in cHL and ALCL lines. BATF3 knockdown using short hairpin RNAs was toxic for cHL and ALCL lines, reducing their proliferation and survival. We identified MYC as a critical BATF3 target and confirmed binding of BATF3 to the MYC promoter. JAK/STAT signaling regulated BATF3 expression, as chemical JAK2 inhibition reduced and interleukin 13 stimulation induced BATF3 expression in cHL lines. Chromatin immunoprecipitation substantiated a direct regulation of BATF3 by STAT proteins in cHL and ALCL lines. In conclusion, we identified STAT-mediated BATF3 expression that is essential for lymphoma cell survival and promoted MYC activity in cHL and ALCL, hence we recognized a new oncogenic axis in these lymphomas.


Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Enfermedad de Hodgkin/genética , Linfoma Anaplásico de Células Grandes/genética , Proteínas Proto-Oncogénicas c-myc/genética , Factores de Transcripción STAT/genética , Regulación hacia Arriba/genética , Carcinogénesis/genética , Carcinogénesis/patología , Línea Celular Tumoral , Proliferación Celular/genética , Supervivencia Celular , Regulación Neoplásica de la Expresión Génica/genética , Enfermedad de Hodgkin/patología , Humanos , Janus Quinasa 2/genética , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/patología , Linfoma Anaplásico de Células Grandes/patología , Oncogenes/genética , Regiones Promotoras Genéticas/genética , ARN Interferente Pequeño/genética , Transducción de Señal/genética , Factor de Transcripción AP-1/genética , Activación Transcripcional/genética
4.
Leukemia ; 30(12): 2283-2292, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27499139

RESUMEN

A key feature of the adaptive immune system is the generation of memory B and T cells and long-lived plasma cells, providing protective immunity against recurring infectious agents. Memory B cells are generated in germinal center (GC) reactions in the course of T cell-dependent immune responses and are distinguished from naive B cells by an increased lifespan, faster and stronger response to stimulation and expression of somatically mutated and affinity matured immunoglobulin (Ig) genes. Approximately 40% of human B cells in adults are memory B cells, and several subsets were identified. Besides IgG+ and IgA+ memory B cells, ∼50% of peripheral blood memory B cells express IgM with or without IgD. Further smaller subpopulations have additionally been described. These various subsets share typical memory B cell features, but likely also fulfill distinct functions. IgM memory B cells appear to have the propensity for refined adaptation upon restimulation in additional GC reactions, whereas reactivated IgG B cells rather differentiate directly into plasma cells. The human memory B-cell pool is characterized by (sometimes amazingly large) clonal expansions, often showing extensive intraclonal IgV gene diversity. Moreover, memory B-cell clones are frequently composed of members of various subsets, showing that from a single GC B-cell clone a variety of memory B cells with distinct functions is generated. Thus, the human memory B-cell compartment is highly diverse and flexible. Several B-cell malignancies display features suggesting a derivation from memory B cells. This includes a subset of chronic lymphocytic leukemia, hairy cell leukemia and marginal zone lymphomas. The exposure of memory B cells to oncogenic events during their generation in the GC, the longevity of these B cells and the ease to activate them may be key determinants for their malignant transformation.


Asunto(s)
Linfocitos B/inmunología , Memoria Inmunológica , Linfocitos B/clasificación , Linfocitos B/citología , Humanos , Isotipos de Inmunoglobulinas , Neoplasias/patología
5.
Leukemia ; 30(4): 844-53, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26658840

RESUMEN

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL)-a subtype of Hodgkin lymphoma (HL)-is characterized by a low content of tumor cells, the lymphocyte predominant (LP) cells. Transformation into diffuse large B-cell lymphoma (DLBCL) occurs in about 10% of patients. We performed whole-genome mutation analysis of the DLBCL components from two composite lymphomas consisting of clonally related NLPHL and DLBCL as a means to identify candidate tumor suppressor genes and oncogenes in NLPHL. The analysis of LP cells for selected mutations of the DLBCL revealed that most mutations are also present in the LP cells, indicating a close relationship between the two components. The analysis of 62 selected genes in NLPHL by targeted ultra-deep sequencing revealed three novel highly recurrently mutated genes (each mutated in ~50% of cases), that is, DUSP2, SGK1 and JUNB. SGK1 was expressed in the LP cells of primary NLPHL cases and in the NLPHL cell line DEV. Administration of an SGK1 inhibitor induced apoptosis in the NLPHL cell line DEV and the DLBCL cell line Farage, suggesting a pathogenetic role of SGK1 in the LP and DLBCL cells. In summary, the present study identifies SGK1, DUSP2 and JUNB as novel key players in the pathogenesis of NLPHL.


Asunto(s)
Fosfatasa 2 de Especificidad Dual/genética , Enfermedad de Hodgkin/genética , Proteínas Inmediatas-Precoces/genética , Mutación/genética , Proteínas Serina-Treonina Quinasas/genética , Factores de Transcripción/genética , Adulto , Análisis Mutacional de ADN , Secuenciación de Nucleótidos de Alto Rendimiento , Enfermedad de Hodgkin/patología , Humanos , Inmunofenotipificación , Ganglios Linfáticos/metabolismo , Ganglios Linfáticos/patología , Linfocitos/metabolismo , Linfocitos/patología , Linfoma Folicular/genética , Linfoma Folicular/patología , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/patología , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico
6.
Leukemia ; 29(2): 456-63, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25027518

RESUMEN

Follicular lymphoma (FL) with a t(14;18) is a B-cell neoplasm clinically characterized by multiple recurrencies. In order to investigate the clonal evolution of this lymphoma, we studied paired primary and relapse tumor samples from 33 patients with recurrent non-transformed t(14;18)-positive FL. We reconstructed phylogenetic trees of the evolution by taking advantage of the activation-induced cytidine deaminase (AID)-mediated somatic hypermutation (SHM) active in the germinal center reaction using sequences of the clonal VHDHJH rearrangements of the immunoglobulin heavy chain (IGH) locus. Mutational analysis of the IGH locus showed evidence for ongoing somatic mutation and for counter-selection of mutations affecting the BCR conformation during tumor evolution. We further followed evolutionary divergence by targeted sequencing of gene loci affected by aberrant SHM as well as of known driver genes of lymphomagenesis, and by array-based genome-wide chromosomal imbalance and DNA methylation analysis. We observed a wide spectrum of evolutionary patterns ranging from almost no evolution to divergent evolution within recurrent non-transformed t(14;18) FL. Remarkably, we observed a correlation of the magnitude of evolutionary divergence across all genetic and epigenetic levels suggesting co-evolution. The distribution of coding mutations in driver genes and the correlation with SHM suggest CREBBP and AID to be potential modifiers of genetic and epigenetic co-evolution in FL.


Asunto(s)
Epigénesis Genética , Linfoma Folicular/genética , Linfoma Folicular/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Cromosomas/ultraestructura , Biología Computacional , Citidina Desaminasa/genética , Metilación de ADN , Análisis Mutacional de ADN , Epigenómica , Evolución Molecular , Eliminación de Gen , Genómica , Humanos , Inmunoglobulinas/inmunología , Persona de Mediana Edad , Mutación , Análisis de Secuencia por Matrices de Oligonucleótidos , Filogenia , Polimorfismo de Nucleótido Simple , Receptores de Antígenos de Linfocitos B/genética , Recurrencia , Translocación Genética
7.
Curr Mol Med ; 14(5): 580-97, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24894178

RESUMEN

MicroRNAs (miRNAs) are a class of small (18~25 nucleotides long) non-coding RNAs that regulate gene expression on the post-transcriptional level. During the last decade, the field of miRNA research has been exponentially expanding, revealing the widespread role of these molecules in numerous biological processes. Aberrant miRNA expression has been documented in multiple haematologic malignancies, including B cell lymphomas. There is compelling evidence that miRNAs can function as oncogenes or tumor suppressor genes in lymphoid malignancies. In this review, we recapitulate the current knowledge of miRNA expression in B cell malignancies and discuss the accumulating evidence for a major role of miRNA deregulation in the development of B cell-derived lymphoid tumors.


Asunto(s)
Leucemia de Células B/genética , Linfoma/genética , MicroARNs/genética , Animales , Regulación Neoplásica de la Expresión Génica/genética , Humanos
8.
Leukemia ; 27(3): 671-9, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23174882

RESUMEN

A hallmark of classical Hodgkin lymphoma (cHL) is that the B-cell-derived Hodgkin and Reed-Sternberg (HRS) tumor cells have largely lost the B-cell-typical gene expression program. The factors causing this 'reprogramming' of HRS cells are only partly understood. As early B-cell factor 1 (EBF1), a major B-cell transcription factor, is downregulated in HRS cells, we analyzed whether this downregulation contributes to the lost B-cell phenotype and tested the consequences of EBF1 re-expression in cHL cell lines. EBF1 re-expression caused an upregulation of B-cell genes, such as CD19, CD79A and CD79B, although the B-cell genes FOXO1 and PAX5 remained lowly expressed. The re-expression of CD19, CD79A and CD79B occurred largely without demethylation of promoter CpG motifs of these genes. In the cHL cell line L-1236 fitness decreased after EBF1 re-expression. These data show that EBF1 has the ability to reintroduce part of the B-cell signature in cHL cell lines. Loss of EBF1 expression in HRS cells therefore contributes to their lost B-cell phenotype. Notably, in the cHL cell line KM-H2 destructive mutations were found in one allele of EBF1, indicating that genetic lesions may sometimes have a role in impairing EBF1 expression.


Asunto(s)
Linfocitos B/patología , Biomarcadores de Tumor/genética , Metilación de ADN , Regulación Neoplásica de la Expresión Génica , Enfermedad de Hodgkin/patología , Células de Reed-Sternberg/patología , Transactivadores/metabolismo , Apoptosis , Linfocitos B/metabolismo , Secuencia de Bases , Biomarcadores de Tumor/metabolismo , Western Blotting , Proliferación Celular , Islas de CpG , Perfilación de la Expresión Génica , Enfermedad de Hodgkin/genética , Enfermedad de Hodgkin/metabolismo , Humanos , Datos de Secuencia Molecular , Análisis de Secuencia por Matrices de Oligonucleótidos , Regiones Promotoras Genéticas , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Células de Reed-Sternberg/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Homología de Secuencia de Ácido Nucleico , Transactivadores/genética
9.
Leukemia ; 26(7): 1654-62, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22307176

RESUMEN

The precise molecular pathogenesis of splenic marginal zone lymphoma (SMZL) is still unknown. Clinical and epidemiological data suggest that chronic hepatitis C virus (HCV) infection may have an etiological role in a subset of cases.We performed a large-scale microRNA (miRNA) expression profiling analysis of 381 miRNAs by quantitative reverse transcription PCR (Q-RT-PCR) of 26 microdissected splenic tissue samples (7 HCV(+) SMZL; 8 HCV(-) SMZL and 11 non-neoplastic splenic controls). Single assay Q-RT-PCR and miRNA in situ hybridization (miRNA-ISH) were used to confirm the results in an independent cohort. Unsupervised hierarchical clustering of miRNA expression profiles demonstrated a distinct signature of SMZL compared with the normal splenic marginal zone. Supervised analysis revealed differentially expressed miRNAs, including miRNAs with previously recognized tumor suppressive or oncogenic potential. Five miRNAs were found significantly overexpressed in SMZL, including miR-21, miR-155 and miR-146a, whereas seven miRNAs showed significantly reduced expression, including miR-139, miR-345, miR-125a and miR-126. Furthermore, we identified miR-26b, a miRNA known to have tumor suppressive properties, as significantly downregulated in SMZL arising in HCV-positive patients (P=0.0016). In conclusion, there is a characteristic dysregulation of miRNA expression in SMZL with a possible implication in its molecular tumorigenesis.


Asunto(s)
Biomarcadores de Tumor/genética , Perfilación de la Expresión Génica , Hepacivirus/aislamiento & purificación , Hepatitis C Crónica/genética , Linfoma de Células B de la Zona Marginal/genética , MicroARNs/genética , Neoplasias del Bazo/genética , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Regulación Neoplásica de la Expresión Génica , Hepatitis C Crónica/virología , Humanos , Hibridación in Situ , Linfoma de Células B de la Zona Marginal/virología , Masculino , Persona de Mediana Edad , Análisis de Secuencia por Matrices de Oligonucleótidos , Pronóstico , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Bazo/metabolismo , Bazo/patología , Neoplasias del Bazo/virología , Adulto Joven
11.
Leukemia ; 25(12): 1797-807, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21818113

RESUMEN

Recent studies addressing the molecular characteristics of PCNSL, which is defined as malignant B-cell lymphoma with morphological features of DLBCL, have significantly improved our understanding of the pathogenesis of this lymphoma entity, which is associated with an inferior prognosis as compared with DLBCL outside the CNS. This unfavorable prognosis stimulated intense efforts to improve therapy and induced recent series of clinical studies, which addressed the role of radiotherapy and various chemotherapeutic regimens. This review combines the discussion of diagnosis, differential diagnosis and recent progress in studies addressing the molecular pathogenesis as well as therapeutic options in PCNSL.


Asunto(s)
Neoplasias del Sistema Nervioso Central/diagnóstico , Neoplasias del Sistema Nervioso Central/genética , Neoplasias del Sistema Nervioso Central/terapia , Humanos
12.
Leukemia ; 24(6): 1152-9, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20428196

RESUMEN

Soluble or membrane-anchored ligands of NKG2D and their receptor have a critical role in the elimination of tumor cells and disease progression. Plasma samples of 98 patients with B-cell chronic lymphocytic leukemia (CLL) were analyzed with specific ELISA systems for soluble major histocompatibility complex class I-related chains (sMICA and sMICB) and UL-16-binding proteins (ULBP1, 2, and 3). The flow cytometric analysis of MICA on CLL cells and natural killer group 2 member D (NKG2D) receptors on NK cells was performed after thawing of frozen peripheral blood lymphocytes of CLL patients (N=51). Levels of sMICA, sMICB, and sULBP2 were significantly increased (P<0.001) compared with 48 controls, whereas sULBP1 3 were not detectable in patients and controls. Levels of sMICA>990 pg/ml (P=0.014), sMICB>200 pg/ml (P=0.0001), and sULBP2>105 pg/ml (P<0.0001) were associated with poor treatment-free survival (TFS). Neither MICA nor NKG2D expression could be related to clinical parameters. In multivariate analysis Binet stage (P=0.002), sULBP2 (P=0.002) and ZAP-70 (P=0.002) were independent predictive factors for TFS. In patients with Binet stage A, sULBP2 levels>105 pg/ml were strongly associated (P=0.0025) with poor TFS. Our data show that soluble but not membrane-anchored NKG2D ligands or receptors are of prognostic significance in CLL. Moreover, sULBP2 seems to be useful to identify early-stage patients with risk of disease progression.


Asunto(s)
Antígenos de Histocompatibilidad Clase I/sangre , Péptidos y Proteínas de Señalización Intercelular/sangre , Leucemia Linfocítica Crónica de Células B/sangre , Estudios de Casos y Controles , Ensayo de Inmunoadsorción Enzimática , Femenino , Citometría de Flujo , Proteínas Ligadas a GPI , Humanos , Leucemia Linfocítica Crónica de Células B/patología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
13.
Leukemia ; 23(11): 2129-38, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19657361

RESUMEN

Anaplastic large cell lymphoma (ALCL) is a main type of T-cell lymphomas and comprises three distinct entities: systemic anaplastic lymphoma kinase (ALK) positive, systemic ALK(-) and cutaneous ALK(-) ALCL (cALCL). Little is known about their pathogenesis and their cellular origin, and morphological and immunophenotypical overlap exists between ALK(-) ALCL and classical Hodgkin lymphoma (cHL). We conducted gene expression profiling of microdissected lymphoma cells of five ALK(+) and four ALK(-) systemic ALCL, seven cALCL and sixteen cHL, and of eight subsets of normal T and NK cells. The analysis supports a derivation of ALCL from activated T cells, but the lymphoma cells acquired a gene expression pattern hampering an assignment to a CD4(+), CD8(+) or CD30(+) T-cell origin. Indeed, ALCL display a down-modulation of many T-cell characteristic molecules. All ALCL types show significant expression of NFkappaB target genes and upregulation of genes involved in oncogenesis (e.g. EZH2). Surprisingly, few genes are differentially expressed between systemic and cALCL despite their different clinical behaviour, and between ALK(-) ALCL and cHL despite their different cellular origin. ALK(+) ALCL are characterized by expression of genes regulated by pathways constitutively activated by ALK. This study provides multiple novel insights into the molecular biology and pathogenesis of ALCL.


Asunto(s)
Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Enfermedad de Hodgkin/genética , Linfoma Anaplásico de Células Grandes/genética , Adolescente , Adulto , Anciano , Quinasa de Linfoma Anaplásico , Línea Celular , Femenino , Enfermedad de Hodgkin/patología , Humanos , Inmunohistoquímica , Células Asesinas Naturales/citología , Células Asesinas Naturales/fisiología , Linfoma Anaplásico de Células Grandes/patología , Masculino , Microdisección , Persona de Mediana Edad , FN-kappa B/metabolismo , Fenotipo , Proteínas Tirosina Quinasas/genética , Proteínas Tirosina Quinasas Receptoras , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Linfocitos T/citología , Linfocitos T/fisiología , Adulto Joven
14.
Br J Haematol ; 142(2): 166-78, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18492111

RESUMEN

Molecular genetic analysis adds important information for lymphoma biology and classification, but the latter is challenged by recent improvement of combined chemo-immunotherapy. In aggressive lymphoma, molecular profiling identifies risk groups with certain genetic background but still the International Prognostic Index (IPI) remains the most important clinically applicable predictor of outcome. In follicular lymphoma (FL), the importance of the meshwork of bystander cells becomes increasingly evident. As combined immuno-chemotherapy improved the prognosis of the patients, several clinical trials indicated that the FLIPI still efficiently discriminates patients at risk for transformation and relapse, although several mechanisms of transformation seem to exist. In mantle cell lymphoma it has been proven that pathogenesis and prognosis mainly depend on deregulation of the cell cycle. A reliable clinical risk score could be established.


Asunto(s)
Linfoma Folicular/patología , Linfoma de Células del Manto/patología , Linfoma/patología , Anticuerpos Monoclonales/uso terapéutico , Ciclo Celular/genética , Humanos , Linfoma/genética , Linfoma/terapia , Linfoma Folicular/genética , Linfoma Folicular/terapia , Linfoma de Células del Manto/genética , Linfoma de Células del Manto/terapia , Pronóstico , Factores de Riesgo
15.
Leukemia ; 21(7): 1532-44, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17495977

RESUMEN

The biologic and pathologic features of B-cell malignancies bearing a translocation t(14;19)(q32;q13) leading to a fusion of IGH and BCL3 are still poorly described. Herein we report the results of a comprehensive cytogenetic, fluorescence in situ hybridization (FISH), molecular and histopathological survey of a large series of B-cell malignancies with t(14;19) or variant translocations. A total of 56 B-cell malignancies with a FISH-proven BCL3 involvement were identified with the translocation partners being IGH (n=51), IGL (n=2), IGK (n=2) and a non-IG locus (n=1). Hierarchical clustering of chromosomal changes associated with the t(14;19) indicated the presence of two different groups of IG/BCL3-positive lymphatic neoplasias. The first group included 26 B-cell malignancies of various histologic subtypes containing a relatively high number of chromosomal changes and mostly mutated IgVH genes. This cluster displayed three cytogenetic branches, one with rearrangements in 7q, another with deletions in 17p and a third one with rearrangements in 1q and deletions in 6q and 13q. The second group included 19 cases, mostly diagnosed as B-cell chronic lymphocytic leukemia (B-CLL), and characterized by few additional chromosomal changes (e.g. trisomy 12) and unmutated IgVH genes. In conclusion, our study indicates that BCL3 translocations are not restricted to B-CLL but present in a heterogeneous group of B-cell malignancies.


Asunto(s)
Leucemia de Células B/genética , Linfoma de Células B/genética , Proteínas Proto-Oncogénicas/genética , Factores de Transcripción/genética , Translocación Genética , Adulto , Anciano , Proteínas del Linfoma 3 de Células B , Cromosomas Humanos Par 14 , Cromosomas Humanos Par 19 , Análisis Citogenético , Femenino , Reordenamiento Génico , Genes de Inmunoglobulinas , Histocitoquímica , Humanos , Hibridación Fluorescente in Situ , Leucemia de Células B/clasificación , Leucemia de Células B/patología , Linfoma de Células B/clasificación , Linfoma de Células B/patología , Masculino , Persona de Mediana Edad
16.
Leukemia ; 21(4): 780-7, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17375124

RESUMEN

Mediastinal large B-cell (MBL) and classical Hodgkin lymphoma (HL) have several pathogenic mechanisms in common. As we recently observed aberrant tyrosine kinase (TK) activities in HL, we now analysed also MBL for such activities. Indeed, MBL and HL were the only B-cell lymphomas where elevated cellular phospho-tyrosine contents were typical features. Three TKs, JAK2, RON and TIE1, not expressed in normal B cells, were each expressed in about 30% of MBL cases, and 75% of cases expressed at least one of the TKs. Among the intracellular pathways frequently triggered by TKs, the PI3K/AKT pathway was activated in about 40% of MBLs and essential for survival of MBL cell lines, whereas the RAF/mitogen-activated protein kinase pathway seemed to be inhibited. No activating mutations were detected in the three TKs in MBL cell lines and primary cases. RON and TIE1 were each also expressed in about 35% and JAK2 in about 53% of HL cases. JAK2 genomic gains are frequent in MBL and HL but we observed no strict correlation of JAK2 genomic status with JAK2 protein expression. In conclusion, aberrant TK activities are a further shared pathogenic mechanism of MBL and HL and may be interesting targets for therapeutic intervention.


Asunto(s)
Regulación Neoplásica de la Expresión Génica , Enfermedad de Hodgkin/genética , Linfoma de Células B/genética , Proteína Oncogénica v-akt/genética , Fosfatidilinositol 3-Quinasas/genética , Proteínas Tirosina Quinasas/genética , Activación Enzimática , Regulación Enzimológica de la Expresión Génica , Enfermedad de Hodgkin/clasificación , Enfermedad de Hodgkin/enzimología , Humanos , Linfoma de Células B/clasificación , Linfoma de Células B/enzimología , Linfoma de Células B Grandes Difuso/enzimología , Linfoma de Células B Grandes Difuso/genética , Proteína Oncogénica v-akt/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Tirosina Quinasas/metabolismo
17.
Leukemia ; 19(8): 1452-8, 2005 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15973455

RESUMEN

Clonally related composite lymphomas of Hodgkin's lymphoma (HL) and Non-Hodgkin's lymphoma (NHL) represent models to study the multistep transformation process in tumorigenesis and the development of two distinct tumors from a shared precursor. We analyzed six such lymphomas for transforming events. The HLs were combined in two cases with follicular lymphoma (FL), and in one case each with B-cell chronic lymphocytic leukemia, splenic marginal zone lymphoma, mantle cell lymphoma (MCL) and diffuse large B-cell lymphoma (DLBCL). In the HL/FL and HL/MCL combinations, BCL2/IGH and CCND1/IGH translocations, respectively, were detected in both the HL and NHL. No mutations were found in the tumor suppressor genes FAS, NFKBIA and ATM. The HL/DLBCL case harbored clonal replacement mutations of the TP53 gene on both alleles exclusively in the DLBCL. In conclusion, we present the first examples of molecularly verified IgH-associated translocations in HL, which also show that BCL2/IGH or CCND1/IGH translocations can represent early steps in the pathogenesis of composite HL/FL or HL/MCL. The restriction of the TP53 mutations to the DLBCL in the HL/DLBCL case exemplifies a late transforming event that presumably happened in the germinal center and affected the fate of a common lymphoma precursor cell towards development of a DLBCL.


Asunto(s)
Transformación Celular Neoplásica/genética , Genes Supresores de Tumor , Cadenas Pesadas de Inmunoglobulina/genética , Linfoma/patología , Mutación , Translocación Genética , Transformación Celular Neoplásica/patología , Células Clonales , Ciclina D1/genética , Genes bcl-2 , Enfermedad de Hodgkin/patología , Humanos , Linfoma/etiología , Linfoma/genética , Linfoma no Hodgkin/patología , Proteína p53 Supresora de Tumor/genética
19.
Ann Oncol ; 13 Suppl 1: 11-8, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12078890

RESUMEN

Significant progress has been made in recent years in our understanding of the cellular origin of Hodgkin and Reed-Sternberg (HRS) cells in Hodgkin's lymphoma (HL). It is now clear that in most instances HRS cells represent clonal populations of transformed germinal centre (GC) B cells. While the tumour cells in the lymphocyte predominant type of the disease resemble mutating and antigen-selected GC B cells, there is evidence that HRS cells in classical HL originate from pre-apoptotic GC B cells. HRS cells of the recently defined novel subtype lymphocyte-rich classical HL moleculary resemble HRS cells of the other types of classical HL, but there appear to be phenotypic differences. In rare cases, HRS cells derive from T cells. In contrast to previous speculations, cell fusion apparently does not play a role in the generation of the tumour clone. By gene expression profiling of HL cell lines, it became evident that HRS cells have lost most of the B cell-typical gene expression program, which may explain why these cells can persist without B cell receptor expression and which suggests that at least one of the transforming events involved in HL pathogenesis affects a master regulator of cell lineage identity.


Asunto(s)
Enfermedad de Hodgkin/patología , Animales , Linfocitos B/patología , Células Clonales , Expresión Génica , Reordenamiento Génico , Enfermedad de Hodgkin/genética , Humanos , Células de Reed-Sternberg/patología , Linfocitos T/patología
20.
Leukemia ; 16(5): 937-9, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-11986957

RESUMEN

The t(2;14)(p13;q32.3) involving the BCL11A and IGH genes is a rare but recurrent chromosomal aberration in B-cell malignancies. Hitherto, juxtaposition of BCL11A and IGH has only been described in B-cell chronic lymphocytic leukemia (B-CLL) and immunocytoma. As subgroups of B-CLL can be distinguished by the pattern of somatic mutation of immunoglobulin variable (V) genes we investigated four lymphomas with IGH/BCL11A involvement for IGH hypermutation. Clonal V(H) gene rearrangements were amplified; in all four cases, sequencing of the amplificates revealed the rearranged V(H) genes to lack somatic mutations. These results suggest that t(2;14)(p13;q32.3) is associated with a subset of B-CLL/immunocytoma characterized by non-mutated IG genes deriving from pre-germinal center B cells. As the translocations in both informative cases are targeted to the switch regions of the IGG2 gene, which is mainly used in T cell-independent immune responses, these translocations presumably occurred in activated B cells in the course of T cell-independent immune responses outside the germinal center.


Asunto(s)
Proteínas Portadoras , Cromosomas Humanos Par 14 , Cromosomas Humanos Par 2 , Cadenas Pesadas de Inmunoglobulina/genética , Leucemia Linfocítica Crónica de Células B/genética , Linfoma de Células B/genética , Mutación , Proteínas de Neoplasias/genética , Proteínas Nucleares , Translocación Genética , Genes de Inmunoglobulinas , Humanos , Región de Cambio de la Inmunoglobulina , Región Variable de Inmunoglobulina/genética , Leucemia Linfocítica Crónica de Células B/clasificación , Leucemia Linfocítica Crónica de Células B/diagnóstico , Linfoma de Células B/diagnóstico , Proteínas Represoras , Análisis de Secuencia de ADN
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