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/genéticaRESUMEN
The suppressors of cytokine signaling (SOCS) are critically involved in the regulation of cellular proliferation, survival, and apoptosis via cytokine-induced JAK/STAT signaling. SOCS-1 silencing by aberrant DNA methylation contributes to oncogenesis in various B-cell neoplasias and carcinomas. Recently, we showed an alternative loss of SOCS-1 function due to deleterious SOCS-1 mutations in a major subset of primary mediastinal B-cell lymphoma (PMBL) and in the PMBL line MedB-1, and a biallelic SOCS-1 deletion in PMBL line Karpas1106P. For both cell lines our previous data demonstrated retarded JAK2 degradation and sustained phospho-JAK2 action leading to enhanced DNA binding of phospho-STAT5. Here, we analysed SOCS-1 in laser-microdissected Hodgkin and Reed-Sternberg (HRS) cells of classical Hodgkin lymphoma (cHL). We detected SOCS-1 mutations in HRS cells of eight of 19 cHL samples and in three of five Hodgkin lymphoma (HL)-derived cell lines by sequencing analysis. Moreover, we found a significant association between mutated SOCS-1 of isolated HRS cells and nuclear phospho-STAT5 accumulation in HRS cells of cHL tumor tissue (P < 0.01). Collectively, these findings support the concept that PMBL and cHL share many overlapping features, and that defective tumor suppressor gene SOCS-1 triggers an oncogenic pathway operative in both lymphomas.
Asunto(s)
Núcleo Celular/metabolismo , Regulación Neoplásica de la Expresión Génica , Genes Supresores de Tumor , Enfermedad de Hodgkin/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Mutación , Proteínas Represoras/genética , Factor de Transcripción STAT5/metabolismo , Proteínas Supresoras de la Señalización de Citocinas/genética , Secuencia de Aminoácidos , Secuencia de Bases , Enfermedad de Hodgkin/metabolismo , Humanos , Rayos Láser , Datos de Secuencia Molecular , Fosforilación , Células de Reed-Sternberg , Homología de Secuencia de Aminoácido , Proteína 1 Supresora de la Señalización de CitocinasAsunto(s)
Enfermedad de Hodgkin/genética , Linfoma de Células B/genética , Linfoma de Células B Grandes Difuso/genética , Neoplasias del Mediastino/genética , Proteínas Tirosina Quinasas/genética , Proteínas Proto-Oncogénicas/genética , Secuencia de Bases , Humanos , Janus Quinasa 2 , Datos de Secuencia Molecular , Mutación , Proteínas Tirosina Quinasas/metabolismo , Proteínas Proto-Oncogénicas/metabolismoAsunto(s)
Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Regulación Neoplásica de la Expresión Génica , Linfoma de Células B/genética , Neoplasias del Mediastino/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Núcleo Celular/metabolismo , Humanos , Linfoma de Células B/metabolismo , Linfoma de Células B/fisiopatología , Neoplasias del Mediastino/metabolismo , Neoplasias del Mediastino/fisiopatología , Proto-Oncogenes Mas , Proteínas RepresorasRESUMEN
Misregulation of REL, a nuclear factor-kappaB family transcription factor, has been implicated in several human lymphoid malignancies. REL has a conserved N-terminal DNA-binding/dimerization domain called the Rel homology domain (RHD) and a C-terminal transactivation domain (TAD). Here, we define the sequences (amino acids (aa) 323-422) between the RHD and TAD as a REL inhibitory domain (RID) because deletion of these sequences increases both REL transactivation and DNA binding. Furthermore, we have characterized two REL mRNA splice variants that encode proteins with alterations near RID: one lacking exon 9 sequences (aa 308-330; RELDelta9) and one with an exonized Alu fragment insertion of 32 aa after aa 307 (REL+Alu). Deletion of RID or exon 9-encoded sequences increases transactivation by GAL4-REL by approximately threefold. Moreover, deletion of RID or exon 9 sequences increases transactivation by full-length REL from certain kappaB site-containing promoters and increases DNA binding by REL. Deletion of RID does not affect REL's ability to transform chicken spleen cells. Reverse transcriptase-polymerase chain reaction analysis of mRNA from both primary lymphoma samples and several transformed tissue culture cell lines indicates that the RELDelta9 splice variant is preferentially expressed in lymphoma, suggesting that the REL transcript lacking exon 9 could serve as a marker for certain types of lymphoid tumors.
Asunto(s)
Empalme Alternativo , Biomarcadores de Tumor/biosíntesis , Transformación Celular Neoplásica/metabolismo , Exones , Regulación Neoplásica de la Expresión Génica , Linfoma/metabolismo , Proteínas Oncogénicas v-rel/biosíntesis , Activación Transcripcional , Empalme Alternativo/genética , Animales , Biomarcadores de Tumor/genética , Transformación Celular Neoplásica/genética , Células Cultivadas , Pollos , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Linfoma/genética , Proteínas Oncogénicas v-rel/genética , Regiones Promotoras Genéticas/genética , Estructura Terciaria de Proteína/genética , Bazo/metabolismo , Activación Transcripcional/genéticaRESUMEN
The pathogenetic relationship of marginal zone B-cell lymphoma (MALT lymphoma) of the gastrointestinal (GI) tract and eventually co-existing aggressive B-cell lymphoma and primary aggressive B-cell lymphoma remains to be elucidated. The RNA of laser-microdissected cells was isolated and amplified from small and/or large cell compartments of eight MALT lymphomas (small cell lymphoma, SCL), 14 GI diffuse large B-cell lymphomas (large cell lymphoma, LCL), and ten GI B-cell lymphomas with composite small and large cell compartments (ComL) and expression analyses were performed using cDNA arrays. Hierarchical cluster analysis clearly separated SCL and LCL and the small and large cell compartments of ComL. Likewise, cluster analysis with all samples of SCL, LCL, and ComL yielded two main 'small cell' and 'large cell' branches. Furthermore, 60 genes were differentially expressed between SCL and LCL, and 82 genes between the small and large cell components of ComL; 26 genes were discriminators in both settings. Use of the profiles of ComL as training sets for class prediction resulted in 95% accuracy for the classification of SCL and LCL. Collectively, the data strongly suggest that both secondary and primary aggressive B-cell lymphomas of the GI tract are blastic marginal zone lymphomas.
Asunto(s)
Neoplasias Gastrointestinales/genética , Perfilación de la Expresión Génica , Linfoma de Células B/genética , Linfoma de Células B Grandes Difuso/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , Transcripción Genética , Neoplasias Gastrointestinales/patología , Marcadores Genéticos , Humanos , Inmunohistoquímica/métodos , Hibridación Fluorescente in Situ , Leucemia Linfocítica Crónica de Células B/genética , Leucemia Linfocítica Crónica de Células B/patología , Linfoma de Células B/patología , Linfoma de Células B Grandes Difuso/patología , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
AIMS: Suppressors of cytokine signaling (SOCS) negatively regulate Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling involved in proliferation, survival, and apoptosis. We previously showed a loss of SOCS-1 function due to deleterious mutations in a major subset of mediastinal B-cell lymphoma (MBL). In MBL cell lines this leads to retarded JAK2 degradation and sustained phospho-STAT5 action results in enhanced DNA binding of phospho-STAT5. METHODS: To investigate the SOCS-1 gene we laser-microdissected Hodgkin-and Reed-Sternberg (HRS) cells of 19 classical Hodgkin lymphoma (cHL) and performed sequencing analysis. To assess phospho-STAT5 status immunohistochemistry on the corresponding paraffin-embedded cHL tumor tissue was done. RESULTS: We detected mutations of the SOCS-1 gene in HRS cells of 8 of 19 cHL samples and in 3 of 5 cHL-derived cell lines. Moreover, we found a significant association between mutated SOCS-1 of isolated HRS cells and nuclear phospho-STAT5 accumulation in HRS cells (P <0.01). CONCLUSIONS: In conclusion, these findings support the concept that MBL and cHL share overlapping features and that defective tumor suppressor gene SOCS-1 triggers an oncogenic pathway operative in both lymphomas.