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1.
Blood ; 132(22): 2401-2405, 2018 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-30257882

RESUMO

Primary mediastinal large B-cell lymphoma (PMBCL) is recognized as a distinct entity in the World Health Organization classification. Currently, the diagnosis relies on consensus of histopathology, clinical variables, and presentation, giving rise to diagnostic inaccuracy in routine practice. Previous studies have demonstrated that PMBCL can be distinguished from subtypes of diffuse large B-cell lymphoma (DLBCL) based on gene expression signatures. However, requirement of fresh-frozen biopsy material has precluded the transfer of gene expression-based assays to the clinic. Here, we developed a robust and accurate molecular classification assay (Lymph3Cx) for the distinction of PMBCL from DLBCL subtypes based on gene expression measurements in formalin-fixed, paraffin-embedded tissue. A probabilistic model accounting for classification error, comprising 58 gene features, was trained on 68 cases of PMBCL and DLBCL. Performance of the model was subsequently evaluated in an independent validation cohort of 158 cases and showed high agreement of the Lymph3Cx molecular classification with the clinicopathological diagnosis of an expert panel (frank misclassification rate, 3.8%). Furthermore, we demonstrate reproducibility of the assay with 100% concordance of subtype assignments at 2 independent laboratories. Future studies will determine Lymph3Cx's utility for routine diagnostic purposes and therapeutic decision making.


Assuntos
Perfilação da Expressão Gênica , Linfoma Difuso de Grandes Células B/diagnóstico , Linfoma não Hodgkin/diagnóstico , Neoplasias do Mediastino/diagnóstico , Estudos de Coortes , Regulação Neoplásica da Expressão Gênica , Humanos , Linfoma Difuso de Grandes Células B/classificação , Linfoma Difuso de Grandes Células B/genética , Linfoma não Hodgkin/classificação , Linfoma não Hodgkin/genética , Neoplasias do Mediastino/classificação , Neoplasias do Mediastino/genética , Mediastino/patologia , Inclusão em Parafina
2.
Blood ; 123(8): 1214-7, 2014 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-24398326

RESUMO

The assignment of diffuse large B-cell lymphoma into cell-of-origin (COO) groups is becoming increasingly important with the emergence of novel therapies that have selective biological activity in germinal center B cell-like or activated B cell-like groups. The Lymphoma/Leukemia Molecular Profiling Project's Lymph2Cx assay is a parsimonious digital gene expression (NanoString)-based test for COO assignment in formalin-fixed paraffin-embedded tissue (FFPET). The 20-gene assay was trained using 51 FFPET biopsies; the locked assay was then validated using an independent cohort of 68 FFPET biopsies. Comparisons were made with COO assignment using the original COO model on matched frozen tissue. In the validation cohort, the assay was accurate, with only 1 case with definitive COO being incorrectly assigned, and robust, with >95% concordance of COO assignment between 2 independent laboratories. These qualities, along with the rapid turnaround time, make Lymph2Cx attractive for implementation in clinical trials and, ultimately, patient management.


Assuntos
Linhagem da Célula/genética , Regulação Neoplásica da Expressão Gênica , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Feminino , Fixadores , Formaldeído , Humanos , Masculino , Pessoa de Meia-Idade , Inclusão em Parafina , Bancos de Tecidos , Transcriptoma , Adulto Jovem
3.
Cancer Biol Ther ; 14(10): 949-61, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-23982416

RESUMO

Diffuse large B cell lymphoma (DLBCL) is an aggressive form of non-Hodgkin lymphoma. While the initial treatment strategy is highly effective, relapse occurs in 40% of cases. Histone deacetylase inhibitors (HDACi) are a promising class of anti-cancer drugs but their single agent efficacy against relapsed DLBCL has been variable, ranging from few complete/partial responses to some stable disease. However, most patients showed no response to HDACi monotherapy for unknown reasons. Here we show that sensitivity and resistance to the hydroxamate HDACi, PXD101, can be modeled in DLBCL cell lines. Sensitivity is characterized by G 2/M arrest and apoptosis and resistance by reversible G 1 growth arrest. These responses to PXD101 are independent of several negative prognostic indicators such as DLBCL subtype, BCL2 and MYC co-expression, and p53 mutation, suggesting that HDACi might be used effectively against highly aggressive DLBCL tumors if they are combined with other therapeutics that overcome HDACi resistance. Our investigation of mechanisms underlying HDACi resistance showed that cyclin-dependent kinase inhibitors (CKIs), p21 and p27, are upregulated by PXD101 in a sustained fashion in resistant cell lines concomitant with decreased activity of the cyclin E/cdk2 complex and decreased Rb phosphorylation. PXD101 treatment results in increased association of CKI with the cyclin E/cdk2 complex in resistant cell lines but not in a sensitive line, indicating that the CKIs play a key role in G 1 arrest. The results suggest several treatment strategies that might increase the efficacy of HDACi against aggressive DLBCL.


Assuntos
Antineoplásicos/farmacologia , Inibidor de Quinase Dependente de Ciclina p21/fisiologia , Inibidor de Quinase Dependente de Ciclina p27/fisiologia , Inibidores de Histona Desacetilases/farmacologia , Ácidos Hidroxâmicos/farmacologia , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Sulfonamidas/farmacologia , Apoptose , Linhagem Celular Tumoral/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Ensaios de Seleção de Medicamentos Antitumorais , Pontos de Checagem da Fase G2 do Ciclo Celular , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Linfoma Difuso de Grandes Células B/metabolismo , Fosforilação , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteína do Retinoblastoma/metabolismo , Regulação para Cima/efeitos dos fármacos
4.
Blood ; 119(6): 1459-67, 2012 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-22167754

RESUMO

Loss of major histocompatibility complex class II (MHC II) expression is associated with poor patient outcome in diffuse large B-cell lymphoma (DLBCL). As MHC II molecules are lost with plasmacytic differentiation in normal cells, we asked whether MHC II loss in DLBCL is associated with an altered differentiation state. We used gene expression profiling, quantum dots, and immunohistochemistry to study the relationship between MHC II and plasma cell markers in DLBCL and plasmablastic lymphoma (PBL). Results demonstrate that MHC II(-) DLBCL immunophenotypically overlap with PBL and demonstrate an inverse correlation between MHC II and plasma cell markers MUM1, PRDM1/Blimp1, and XBP1s. In addition, MHC II expression is significantly higher in germinal center-DLBCL than activated B cell-DLBCL. A minor subset of cases with an unusual pattern of mislocalized punctate MHC II staining and intermediate levels of mRNA is also described. Finally, we show that PBL is negative for MHC II. The results imply a spectrum of MHC II expression that is more frequently diminished in tumors derived from B cells at the later stages of differentiation (with complete loss in PBL). Our observations provide a possible unifying concept that may contribute to the poor outcome reported in all MHC II(-) B-cell tumors.


Assuntos
Diferenciação Celular/genética , Antígenos de Histocompatibilidade Classe II/genética , Linfoma Difuso de Grandes Células B/genética , Plasmócitos/metabolismo , Análise de Variância , Antígenos CD20/genética , Antígenos CD20/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Antígenos HLA-DR/genética , Antígenos HLA-DR/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Imuno-Histoquímica , Fatores Reguladores de Interferon/genética , Fatores Reguladores de Interferon/metabolismo , Linfoma de Células B/genética , Linfoma de Células B/metabolismo , Linfoma Difuso de Grandes Células B/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Plasmócitos/patologia , Fator 1 de Ligação ao Domínio I Regulador Positivo , Fatores de Transcrição de Fator Regulador X , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína 1 de Ligação a X-Box
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