Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 44
Filtrar
1.
Int J Biochem Cell Biol ; 143: 106152, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34974185

RESUMO

MDC1, a mediator of DNA damage response, recruits other repair proteins on double-strand break (DSB) sites. MDC1 is necessary for activating checkpoint kinases Chk1 and Chk2. It is unclear whether Chk1 interacts with MDC1. MDC1 also comprises many discrete domains. The role of the proline-serine-threonine (PST)-repeat domain of MDC1 in the DNA damage response is unclear. Here, we showed that MDC1 directly binds Chk1 through this PST-repeat region. Phosphorylation of Chk1 by ionizing radiation (IR) also required this PST-repeat domain. Degradation of intact MDC1 was accelerated depending on the PST-repeat domain after IR exposure. In the IR damage response, the PST-repeat-deleted MDC1 levels remained elevated with slow degradation. This abnormal regulation of MDC1 was F-box- and WD40 repeat-containing 7 (FBXW7)-dependent. The mutation of lysine 1413 within the PST-repeat of MDC1 deregulated MDC1 with or without damage. K1413R mutant and PST-deleted MDC1 displayed reduced ability to repair the damaged genome post-IR exposure. These results provide that the PST domain of MDC1 is involved in Chk1 and DNA repair activation. The findings suggest new insights into how MDC1 connects the checkpoint and DNA repair in the DNA damage response.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Ciclo Celular/metabolismo , Quinase 1 do Ponto de Checagem/metabolismo , Prolina/metabolismo , Serina/metabolismo , Treonina/metabolismo , Quebras de DNA de Cadeia Dupla , Humanos , Fosforilação , Transfecção
2.
BMC Cancer ; 21(1): 82, 2021 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-33468080

RESUMO

BACKGROUND: BCOR acts as a corepressor of BCL6, a potent oncogenic protein in cancers of the lymphoid lineage. We have found the recurrent somatic mutation of BCOR occurred in mature T-cell lymphoma (TCL). The role of BCOR mutation in lymphoid malignancies is unknown. METHODS: Lymphoma patient samples were analyzed to identify missense mutations in BCOR using Sanger sequencing. Transfection, RNA interference, immunoprecipitation, western blotting, cell proliferation, cytokine assays and quantitative real-time PCR were employed to determine the functional relevance of the novel K607E mutation in BCOR. The significant transcriptional changes were analyzed by performing DNA microarray profiling in cells expressing BCOR K607E mutant. RESULTS: One hundred thirty-seven lymphoma patient samples were analyzed to identify K607E mutation of the BCOR gene. The BCOR K607E mutation was identified in 15 of 47 NK/T cell lymphoma cases (31.9%), 2 of 18 angioimmunoblastic T-cell lymphoma cases (11.1%), 10 of 30 peripheral T-cell lymphoma, not otherwise specified cases (33.3%), and 13 of 42 diffuse large B-cell lymphoma cases (30.9%). Molecular analysis of BCOR K607E mutation revealed that compared to the wild-type BCOR, the mutant BCOR bound to the BCL6, PCGF1, and RING1B proteins with lesser affinity. Ectopic expression of BCOR K607E mutant significantly enhanced cell proliferation, AKT phosphorylation and the expression of interleukin-2 (IL-2) with up-regulated expression of HOX and S100 protein genes in T cells. BCOR silencing also significantly enhanced cell proliferation, AKT phosphorylation, and IL-2 production. CONCLUSIONS: Functional analyses indicated that K607E mutation of BCOR is oncogenic in nature and can serve as a genetic marker of T-cell lymphoma.


Assuntos
Biomarcadores Tumorais/genética , Carcinogênese/genética , Linfoma de Células T/genética , Recidiva Local de Neoplasia/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Repressoras/genética , Biomarcadores Tumorais/metabolismo , Proliferação de Células/genética , Análise Mutacional de DNA , Perfilação da Expressão Gênica , Regulação Leucêmica da Expressão Gênica , Humanos , Células Jurkat , Linfoma de Células T/diagnóstico , Linfoma de Células T/epidemiologia , Linfoma de Células T/terapia , Mutação , Recidiva Local de Neoplasia/epidemiologia , Recidiva Local de Neoplasia/prevenção & controle , Proteínas Proto-Oncogênicas/metabolismo , Interferência de RNA , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Repressoras/metabolismo , Regulação para Cima
3.
Oncoimmunology ; 9(1): 1746553, 2020 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-32923110

RESUMO

A missense mutation in RHOA encoding p.Gly17 Val has been reported to occur frequently in angioimmunoblastic T-cell lymphoma (AITL). Here, we describe a murine model which expresses the human RHOA mutant gene product in a T-cell specific manner and develops AITL-like symptoms. Most transgenic mice feature with latency one or two enlarged lymph nodes characterized by aberrant lymph node architecture, extensive lymphocytic infiltration, extrafollicular meshwork of follicular dendritic cells (FDC) and arborized endothelial venules. Importantly, we provide evidence for expansion of PD-1+ follicular helper T (Tfh) cells which are the neoplastic cells of AITL. In addition, we saw proliferation of B-cells leading to hypergammaglobulinemia and the presence of dominant T cell clonal populations. Transplantation of lymph node cells to immunocompromised mice partly recreated lymphadenopathy after a long latency and with low penetrance suggesting that cells have undergone partial transformation to a premalignant state. Transcriptomic profiling revealed that the gene expression pattern within affected lymph nodes of the mice closely resembles that of AITL patients with the identical RHOA p.Gly17 Val mutation. The murine model should, therefore, be useful in dissecting pathogenesis of AITL at the molecular level particularly for the cases with the RHOA p.Gly17Val mutation.


Assuntos
Linfadenopatia Imunoblástica , Linfoma de Células T , Animais , Humanos , Linfadenopatia Imunoblástica/genética , Camundongos , Mutação , Reação em Cadeia da Polimerase , Proteína rhoA de Ligação ao GTP/genética
4.
Int J Mol Sci ; 21(12)2020 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-32575557

RESUMO

Double-hit lymphoma (DHL) and double-expressor lymphoma (DEL) are aggressive forms of lymphoma that require better treatments to improve patient outcomes. CKD-581 is a new histone deacetylase (HDAC) inhibitor that exhibited a better safety profile in clinical trials compared to other HDAC inhibitors. Here, we demonstrate that CKD-581 inhibited the class I-II HDAC family via histone H3 and tubulin acetylation. CKD-581 treatment also up-regulated the phosphorylation of histone H2AX (γH2AX, DNA double-strand break marker), and reduced levels of MYC and anti-apoptotic proteins such as BCL-2, BCL-6, BCL-XL, and MCL-1 in DH/DE-diffuse large B cell lymphoma (DLBCL) cell lines. Ultimately, CKD-581 also induced apoptosis via poly(ADP ribose) polymerase 1 (PARP1) cleavage. In a DLBCL SCID mouse xenograft model, CKD-581 exhibited anti-cancer effects comparable with those of rituximab (CD20 mAb). Our findings suggest that CKD-581 could be a good candidate for the treatment of DLBCL.


Assuntos
Inibidores de Histona Desacetilases/administração & dosagem , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Compostos Orgânicos/administração & dosagem , Acetilação , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Inibidores de Histona Desacetilases/farmacologia , Histonas/metabolismo , Linfoma Difuso de Grandes Células B/metabolismo , Camundongos SCID , Compostos Orgânicos/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Tubulina (Proteína)/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Appl Immunohistochem Mol Morphol ; 28(10): 731-740, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32287077

RESUMO

In the era of precision medicine, accurate and reproducible assignment of cell-of-origin (COO) in diffuse large B-cell lymphoma patients has become important. The Lymph2Cx assay is accurately determining COO by analyzing RNA expression of 20 selected genes while the Hans algorithm based on immunohistochemistry is the most popular method for routine daily diagnosis. However, there are discrepancies between the 2 methods, which need to be evaluated for better correlation. We prospectively analyzed 156 cases of diffuse large B-cell lymphoma, not otherwise specified to analyze the characteristics of discrepancy groups of COO determined by Lymph2Cx and Hans algorithm. We investigated the pattern and cause of discrepancy of COO assigned by the 2 methods. Hans algorithm classified 50 cases (32%) as germinal-center B-cell-like (GCB) type and 106 cases (68%) as non-GCB type. Lymph2Cx assay assigned 43 cases (28%) as GCB type, 94 cases (60%) as activated B-cell-like type, and 19 cases (12%) as intermediate/unclassified type. The agreement rate was 86% after exclusion of unclassified type. With regard to the clinicopathologic factors related with discrepancy between Hans algorithm and Lymph2Cx assay, endoscopic biopsy of the gastrointestinal tract (4/11, 36%) showed higher discrepancy rate (P=0.052). Immunophenotypically, CD10/BCL6/MUM1 GCB type and CD10/BCL6//MUM1 (=30%, low level expression) non-GCB type exhibited a significantly higher discrepancy rate (6/13, 46%; 4/13, 31%) (P=0.0001). Activated B-cell-like subgroup via Lymph2Cx assay predicted poor progression-free survival (mean survival duration 28.6 mo, P=0.049) compared with the GCB and unclassified type. Hans algorithm revealed no significant difference in progression-free survival and overall survival (P=0.122 and 0.121). These results suggest that when assigning COO via Hans algorithm, CD10/BCL6/MUM1 GCB type and CD10/BCL6/MUM1 (=30%, low level) non-GCB type require careful interpretation, especially if the MUM1 staining is weak and heterogeneous in the biopsied specimen.


Assuntos
Linfoma Difuso de Grandes Células B/diagnóstico , RNA/análise , Algoritmos , Biomarcadores Tumorais , Biópsia , Humanos , Imuno-Histoquímica , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/mortalidade , Neprilisina/metabolismo , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Análise de Sobrevida
7.
Mod Pathol ; 31(9): 1418-1428, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29765142

RESUMO

Gastric extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue is a distinct entity in that Helicobacter pylori infection plays the most important causative role in the development of the disease. To investigate the genomic alteration in gastric marginal zone lymphoma that was resistant to the H. pylori eradication therapy, we analyzed 19 cases of the gastric marginal zone lymphoma using fluorescence in situ hybridization for MALT1, BCL10 rearrangement, and targeted sequencing using an Illumina platform. Major genetic alterations affected genes involved in nuclear factor (NF)-κB pathway activation and included MALT1 rearrangement (39%), and somatic mutations of TRAF3 (21%), TNFAIP3 (16%), and NOTCH1 (16%). In the MALT1 rearrangement-negative group, disruptive somatic mutations of TRAF3 were the most common alterations (4/12, 33%), followed by somatic mutations of TNFAIP3 (3/12, 25%), and NOTCH1 (3/12, 25%). The present study confirms that genes involved in activation of NF-κB-signaling pathways are a major driver in oncogenesis of H. pylori eradication-resistant gastric marginal zone lymphoma and revealed that TRAF3 mutation is a major contributor in MALT1 rearrangement-negative gastric marginal zone lymphoma.


Assuntos
Rearranjo Gênico , Linfoma de Zona Marginal Tipo Células B/genética , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa/genética , Neoplasias Gástricas/genética , Fator 3 Associado a Receptor de TNF/genética , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/genética , Adulto , Proteína 10 de Linfoma CCL de Células B/genética , Feminino , Infecções por Helicobacter/genética , Infecções por Helicobacter/patologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Hibridização in Situ Fluorescente , Linfoma de Zona Marginal Tipo Células B/patologia , Masculino , Pessoa de Meia-Idade , Mutação , NF-kappa B/genética , Estadiamento de Neoplasias , Estudos Retrospectivos , Transdução de Sinais/genética , Neoplasias Gástricas/patologia
8.
Oncotarget ; 8(10): 17038-17049, 2017 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-28152507

RESUMO

Ocular marginal zone lymphoma is a common type of low-grade B-cell lymphoma. To investigate the genomic changes that occur in ocular marginal zone lymphoma, we analyzed 10 cases of ocular marginal zone lymphoma using whole-genome and RNA sequencing and an additional 38 cases using targeted sequencing. Major genetic alterations affecting genes involved in nuclear factor (NF)-κB pathway activation (60%), chromatin modification and transcriptional regulation (44%), and B-cell differentiation (23%) were identified. In whole-genome sequencing, the 6q23.3 region containing TNFAIP3 was deleted in 5 samples (50%). In addition, 5 structural variation breakpoints in the first intron of IL20RA located in the 6q23.3 region was found in 3 samples (30%). In targeted sequencing, a disruptive mutation of TNFAIP3 was the most common alteration (54%), followed by mutations of TBL1XR1 (18%), cAMP response element binding proteins (CREBBP) (17%) and KMT2D (6%). All TBL1XR1 mutations were located within the WD40 domain, and TBL1XR1 mutants transfected into 293T cells increased TBL1XR1 binding with nuclear receptor corepressor (NCoR), leading to increased degradation of NCoR and the activation of NF-κB and JUN target genes. This study confirms genes involving in the activation of the NF-kB signaling pathway is the major driver in the oncogenesis of ocular MZL.


Assuntos
Proteína de Ligação a CREB/genética , Neoplasias Oculares/genética , Linfoma de Zona Marginal Tipo Células B/genética , Mutação , Proteínas Nucleares/genética , Receptores Citoplasmáticos e Nucleares/genética , Proteínas Repressoras/genética , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteína de Ligação a CREB/metabolismo , Linhagem Celular Tumoral , Deleção Cromossômica , Cromossomos Humanos Par 6/genética , Neoplasias Oculares/metabolismo , Feminino , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Immunoblotting , Linfoma de Zona Marginal Tipo Células B/metabolismo , Masculino , Microscopia Confocal , Pessoa de Meia-Idade , NF-kappa B/genética , NF-kappa B/metabolismo , Proteínas Nucleares/metabolismo , Interferência de RNA , Receptores Citoplasmáticos e Nucleares/metabolismo , Proteínas Repressoras/metabolismo , Transdução de Sinais/genética , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/metabolismo
9.
Mod Pathol ; 30(1): 4-14, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27687005

RESUMO

The prognostic role of MYC has been well documented in non-central nervous system diffuse large B-cell lymphoma; however, it remains controversial in central nervous system diffuse large B-cell lymphoma. To investigate the prognostic value of MYC, we analyzed the MYC protein expression by immunohistochemistry, mRNA expression by RNA in situ hybridization, and gene status by fluorescence in situ hybridization in 74 cases of central nervous system diffuse large B-cell lymphoma. Moreover, we examined the correlation between MYC translocation, mRNA expression, and protein expression. The mean percentage of MYC immunopositive cells was 49%. Using a 44% cutoff value, 49 (66%) cases showed MYC protein overexpression. The result of mRNA in situ hybridization using the RNA scope technology was obtained using the H-scoring system; the median value was 34.2. Using the cutoff value of 63.5, 16 (22%) cases showed MYC mRNA overexpression. MYC gene rearrangement was detected in five out of 68 (7%) cases. MYC translocation showed no statistically significant correlation with mRNA expression; however, all MYC translocation-positive cases showed MYC protein overexpression, with a higher mean percentage of MYC protein expression than that of translocation-negative cases (78 vs 48%, P=0.001). The level of MYC mRNA expression was moderately correlated with the level of MYC protein expression (P<0.001). The mean percentage of MYC protein expression in the high MYC mRNA group was higher than that in the low MYC mRNA group (70 vs 47%, P<0.001). A univariate analysis showed that age over 60 years, Eastern Cooperative Oncology Group (ECOG) performance status ≥2 and MYC protein overexpression were significantly associated with an increased risk of death. MYC translocation and MYC mRNA expression had no prognostic significance. On multivariate analysis, MYC protein overexpression and ECOG score retained prognostic significance.


Assuntos
Neoplasias do Sistema Nervoso Central/metabolismo , Linfoma Difuso de Grandes Células B/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/metabolismo , Neoplasias do Sistema Nervoso Central/genética , Neoplasias do Sistema Nervoso Central/patologia , Feminino , Rearranjo Gênico , Humanos , Imuno-Histoquímica , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Proteínas Proto-Oncogênicas c-myc/genética , Adulto Jovem
10.
Oncotarget ; 7(52): 86433-86445, 2016 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-27835906

RESUMO

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma. Although rituximab therapy improves clinical outcome, some patients develop resistant DLBCL; however, the genetic alterations in these patients are not well documented. To identify the genetic background of refractory DLBCL, we conducted whole-exome sequencing and transcriptome sequencing for six patients with refractory and seven with responsive DLBCL. The average numbers of pathogenic somatic single nucleotide variants and indels in coding regions were 71 in refractory patients (range 28-120) and 38 (range 19-66) in responsive patients. Missense mutations of TP53 were exclusive in 50% (3/6) of refractory patients and involved the DNA-binding domain of TP53. All missense mutations of TP53 were accompanied by copy number deletions. RAB11FIP5, PRKCB, PRDM15, FNBP4, AHR, CEP128, BRE, DHX16, MYO6, and NMT1 mutations were recurrent in refractory patients. MYD88, B2M, SORCS3, and WDFY3 mutations were more frequent in refractory patients than in responsive patients. REL-BCL11A fusion was found in two refractory patients; one had both fusion and copy number gain. Recurrent copy gains of POU2AF1, SLC1A4, REL11, FANCL, CACNA1D, TRRAP, and CUX1 with significantly increased average expression were found in refractory patients. The expression profile revealed enriched gene sets associated with treatment resistance, including oxidative phosphorylation and ATP-binding cassette transporters. In conclusion, this study integrated both genomic and transcriptomic alterations associated with refractory DLBCL and found several treatment-resistance alterations that may contribute to refractoriness.


Assuntos
Exoma , Linfoma Difuso de Grandes Células B/genética , Transcriptoma , Variações do Número de Cópias de DNA , Fusão Gênica , Genes p53 , Humanos , Mutação
11.
Biochem Biophys Res Commun ; 479(1): 5-11, 2016 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-27590578

RESUMO

TopBP1 has been identified as a direct activator of ATR and interacts with the Nbs1 subunit of the Mre11-Rad50-Nbs1 (MRN) complex in egg extracts in a checkpoint-regulated manner. In this study, we show that Mdc1 associates with both TopBP1 and Nbs1 in egg extracts and human cells. We cloned a cDNA encoding the full-length version of Xenopus Mdc1. The association between Mdc1 and TopBP1 involves the first pair of BRCT repeats in TopBP1. The N-terminal region (161-230) of Mdc1 is required for this binding. The interaction between Mdc1 and Nbs1 involves the two tandem BRCT repeats of Nbs1. Functional studies with mutated forms of Mdc1, TopBP1, and Nbs1 indicate that the BRCT-dependent association of these proteins is critical for a normal checkpoint response to DSBs. TopBP1 cannot interact with Nbs1 in Mdc1-depleted egg extracts, suggesting that Mdc1 connects TopBP1 and Nbs1 together. These findings suggest that Mdc1 is a crucial mediator of the DNA damage checkpoint response.


Assuntos
Proteínas de Transporte/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Quebras de DNA de Cadeia Dupla , Proteínas Supressoras de Tumor/metabolismo , Proteínas de Xenopus/metabolismo , Animais , Proteínas de Transporte/genética , Extratos Celulares/química , Linhagem Celular Tumoral , Proteínas Cromossômicas não Histona/genética , Enzimas Reparadoras do DNA , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Feminino , Células HEK293 , Células HeLa , Humanos , Immunoblotting , Proteína Homóloga a MRE11 , Modelos Biológicos , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo , Oócitos/citologia , Oócitos/metabolismo , Óvulo/citologia , Óvulo/metabolismo , Ligação Proteica , Proteínas Supressoras de Tumor/genética , Proteínas de Xenopus/genética , Xenopus laevis
12.
Oncotarget ; 7(11): 12359-71, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26848863

RESUMO

Immunoglobulin (Ig) gene rearrangements remain largely unmodified during the clonal expansion of neoplastic cells. We investigated the clonal relationships between lymphoma components at diagnosis and at relapse by analyzing Ig gene rearrangements. A BIOMED-2 multiplex polymerase chain reaction (PCR) assay was performed in 27 patients using formalin-fixed paraffin embedded tissues, with subsequent cloning and sequencing of the amplified Ig genes in 17 patients. All 27 cases of primary and corresponding relapsed tumors showed monoclonal rearrangements of the Ig genes by BIOMED-2 PCR. Whereas IgVH or IgVK fragment lengths were identical in 8/27 pairs (30%), fragment lengths differed in 19/27 pairs (70%). In 17 cases analyzed by sequencing, an identical VDJ gene rearrangement was confirmed in 4/4 pairs (100%) with the same fragment lengths and in 10/13 pairs (77%) with different fragment lengths. Four of 17 primary lymphomas had multiple VDJ rearrangements, and three of them showed an unrelated relapse. Unrelated relapse was observed in 1/8 mantle cell lymphomas, 1/5 diffuse large B-cell lymphomas, and a large B cell lymphoma developed in a patient with a small lymphocytic lymphoma. Unrelated relapses developed after a longer disease-free interval and tended to show poorer outcome compared with related relapse. In summary, relapse of a lymphoma from an unrelated clone is uncommon, but can occur in B-cell lymphomas. Clonal relationships should be determined by sequencing of the Ig genes, and not just by comparing the PCR product size.


Assuntos
Cadeias Pesadas de Imunoglobulinas/genética , Linfoma de Células B/genética , Recidiva Local de Neoplasia/genética , Adulto , Idoso , Sequência de Bases , Células Clonais , Estudos de Coortes , Feminino , Rearranjo Gênico , Humanos , Linfoma de Células B/patologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Adulto Jovem
13.
Haematologica ; 101(6): 757-63, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26819049

RESUMO

CTLA4 and CD28 are co-regulatory receptors with opposite roles in T-cell signaling. By RNA sequencing, we identified a fusion between the two genes from partial gene duplication in a case of angioimmunoblastic T-cell lymphoma. The fusion gene, which codes for the extracellular domain of CTLA4 and the cytoplasmic region of CD28, is likely capable of transforming inhibitory signals into stimulatory signals for T-cell activation. Ectopic expression of the fusion transcript in Jurkat and H9 cells resulted in enhanced proliferation and AKT and ERK phosphorylation, indicating activation of downstream oncogenic pathways. To estimate the frequency of this gene fusion in mature T-cell lymphomas, we examined 115 T-cell lymphoma samples of diverse subtypes using reverse transcriptase polymerase chain reaction analysis and Sanger sequencing. We identified the fusion in 26 of 45 cases of angioimmunoblastic T-cell lymphomas (58%), nine of 39 peripheral T-cell lymphomas, not otherwise specified (23%), and nine of 31 extranodal NK/T cell lymphomas (29%). We further investigated the mutation status of 70 lymphoma-associated genes using ultra-deep targeted resequencing for 74 mature T-cell lymphoma samples. The mutational landscape we obtained suggests that T-cell lymphoma results from diverse combinations of multiple gene mutations. The CTLA4-CD28 gene fusion is likely a major contributor to the pathogenesis of T-cell lymphomas and represents a potential target for anti-CTLA4 cancer immunotherapy.


Assuntos
Antígenos CD28/genética , Antígeno CTLA-4/genética , Linfoma de Células T/genética , Linfoma de Células T/patologia , Proteínas de Fusão Oncogênica/genética , Linhagem Celular Tumoral , Proliferação de Células , Biologia Computacional/métodos , Citocinas/metabolismo , Dosagem de Genes , Perfilação da Expressão Gênica , Ordem dos Genes , Estudos de Associação Genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Linfoma de Células T/metabolismo , Mutação , Fenótipo , Reprodutibilidade dos Testes
15.
Oncotarget ; 6(19): 17764-76, 2015 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-25980440

RESUMO

Extranodal NK/T-cell lymphoma nasal type (ENKL) is a rare type of non-Hodgkin lymphoma that more frequently occurs in East Asia and Latin America. Even though its molecular background has been discussed in the last few years, the current knowledge does not explain the disease pathogenesis in most cases of ENKL. Here, we performed multiple types of next-generation sequencing on 34 ENKL samples, including whole-exome sequencing (9 cancer tissues and 4 cancer cell lines), targeted sequencing (21 cancer tissues), and RNA sequencing (3 cancer tissues and 4 cancer cell lines). Mutations were found most frequently in 3 genes, STAT3, BCOR, and MLL2 (which were present in 9, 7, and 6 cancer samples, respectively), whereas there were only 2 cases of JAK3 mutation. In total, JAK/STAT pathway- and histone modification-related genes accounted for 55.9% and 38.2% of cancer samples, respectively, and their involvement in ENKL pathogenesis was also supported by gene expression analysis. In addition, we provided 177 genes upregulated only in cancer tissues, which appear to be linked with angiocentric and angiodestructive growth of ENKL. In this study, we propose several novel driver genes of ENKL, and show that these genes and their functional groups may be future therapeutic targets of this disease.


Assuntos
Histonas/genética , Janus Quinases/genética , Linfoma Extranodal de Células T-NK/genética , Fatores de Transcrição STAT/genética , Análise Mutacional de DNA , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Transdução de Sinais/genética
16.
PLoS One ; 10(5): e0126830, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25973791

RESUMO

Irinotecan, an analogue of camptothecin, is frequently used as a single agent or in combination with other anticancer drugs for the treatment of colorectal cancer. However, the drug resistance of tumors is a major obstacle to successful cancer treatment. In this study, we established that cells acquire chronic resistance to irinotecan. We profiled their differential gene expression using microarray. After gene ontology (GO) and KEGG pathway analysis of the microarray data, we specifically investigated whether Sestrin3 could decrease irinotecan resistance. Our results revealed that Sestrin3 enhanced the anticancer effect of irinotecan in vitro in LoVo cells that had acquired resistance to irinotecan. Irinotecan-resistant LoVo cells showed lower reactive oxygen species (ROS) production than their irinotecan-sensitive parental cells. ROS production was increased by Sestrin3 knockdown in irinotecan-resistant LoVo cells. Our results indicate that Sestrin3 might be a good target to develop therapeutics that can help to overcome resistance to irinotecan.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Camptotecina/análogos & derivados , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Proteínas de Choque Térmico/metabolismo , Camptotecina/farmacologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Células HCT116 , Proteínas de Choque Térmico/antagonistas & inibidores , Proteínas de Choque Térmico/genética , Humanos , Irinotecano , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transcriptoma/efeitos dos fármacos
17.
Anticancer Res ; 35(6): 3333-40, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26026093

RESUMO

AIM: The purpose of the present study was to compare microarray gene-expression profiling data between primary central nervous system (CNS) lymphoma and non-CNS lymphomas. MATERIALS AND METHODS: We performed whole-genomic cDNA-mediated annealing, selection and ligation assay with 177 formalin-fixed paraffin-embedded tumor samples. RESULTS: We identified 20 differentially expressed genes out of which 5 were predominantly expressed in CNS DLBCL compared to non-CNS DLBCL (C16orf59, SLC16A9, HPDL, SPP1, and MAG). SLC16A9 may be involved in aerobic glycolysis of malignant tumors. The alteration in gene expression of SPP1 in primary CNS lymphoma is involved in biological activity, such as CNS tropism, B-cell migration, proliferation, and aggressive clinical behavior. MAG may be an important adhesion molecule that contributes to perineural cancer invasion. CONCLUSION: Genomic differences between CNS and non-CNS DLBCL exist and the most prominent genes are SPP1 and MAG. SPP1 may play a key role in CNS tropism of primary CNS lymphoma.


Assuntos
Biomarcadores Tumorais/biossíntese , Neoplasias do Sistema Nervoso Central/genética , Linfoma Difuso de Grandes Células B/genética , Proteínas de Neoplasias/biossíntese , Idoso , Linfócitos B/metabolismo , Linfócitos B/patologia , Neoplasias do Sistema Nervoso Central/patologia , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Linfoma Difuso de Grandes Células B/patologia , Masculino , Análise em Microsséries , Pessoa de Meia-Idade
18.
Genes Chromosomes Cancer ; 54(6): 383-96, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25832818

RESUMO

Viral oncogenes and host immunosenescence have been suggested as causes of Epstein-Barr virus-positive diffuse large B-cell lymphoma (EBV + DLBCL) of the elderly. To investigate the molecular genetic basis of immune evasion and tumor outgrowth, we analyzed copy number alterations (CNAs) and gene expression profiles in EBV + DLBCL samples compared with EBV - DLBCL. There were relatively few genomic alterations in EBV + DLBCL compared with those detected in EBV-negative DLBCL. The most frequent CNAs (>30%) in EBV + DLBCLs were gains at 1q23.2-23.3, 1q23.3, 1q32.1, 5p15.3, 8q22.3, 8q24.1-24.2, and 9p24.1; losses at 6q27, 7q11.2, and 7q36.2-36.3 were also recurrent. A gene expression profile analysis identified the host immune response as a key molecular signature in EBV + DLBCL. Antiviral response genes, proinflammatory cytokines, and chemokines associated with the innate immune response were overexpressed, indicating the presence of a virusinduced inflammatory microenvironment. Genes associated with the B-cell receptor signaling pathway were downregulated. An integrated analysis indicated that SLAMF1 and PDL2 were key targets of the gains detected at 1q23.2-23.3 and 9p24.1. The chromosomal gain at 9p24.1 was associated with poor overall survival. Taken together, our results led to the identification of recurrent copy number alterations and distinct gene expression associated with the host immune response in EBV + DLBCL. We suggest that the upregulation of PDL2 on 9p24.1 promotes immune evasion and is associated with poor prognosis in EBV + DLBCL.


Assuntos
Variações do Número de Cópias de DNA , Perfilação da Expressão Gênica , Herpesvirus Humano 4/genética , Linfoma de Células B/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Cromossomos Humanos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
Haematologica ; 100(3): e106-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25480498
20.
Int J Cancer ; 136(2): 310-21, 2015 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-24895167

RESUMO

CD10 expression was identified as a contributor to cancer progression in several cancers; however, the exact biological significance and mechanism of CD10 expression remains unclear. In addition, CD10 expression in esophageal squamous cell carcinoma (ESCC) has not been studied. We investigated the relationship between CD10 and Twist1. Furthermore, we examined the effect of CD10 on tumorigenicity using in vivo and in vitro systems as well as establishing the clinical significance of CD10 expression in ESCC using large clinical samples. CD10 expression was upregulated by Twist1 and there was a strong correlation between mRNA and protein expression. Twist1 can specifically upregulate CD10 at the transcriptional level via an interaction with the promoter region of CD10 and the proximal E-box CAGGTG in the CD10 promoter was identified as a binding site for Twist1. CD10 is frequently expressed in ESCC cell lines and silencing CD10 suppresses migration/invasion and anchorage-independent tumor growth of ESCC cells. Knockdown of CD10 inhibits the growth of ESCC xenograft in nude mice, suggesting that CD10 plays a role in enhancing the tumorigenesis of ESCC. From among 153 ESCC samples, 46 (30.0%) showed varying degrees of CD10 expression in cancer cells. In addition, stromal fibroblasts also showed varying amounts of CD10 expression in 92 (60.9%) tumor samples. CD10 overexpression in cancer cells as well as in stromal fibroblasts was an independent poor prognostic factor in both overall survival and disease-free survival. CD10 could be a promising target for the treatment of ESCC.


Assuntos
Carcinoma de Células Escamosas/patologia , Movimento Celular , Proliferação de Células , Neoplasias Esofágicas/patologia , Neprilisina/metabolismo , Proteínas Nucleares/metabolismo , Proteína 1 Relacionada a Twist/metabolismo , Idoso , Animais , Apoptose , Western Blotting , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/mortalidade , Adesão Celular , Imunoprecipitação da Cromatina , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/mortalidade , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Citometria de Fluxo , Humanos , Técnicas Imunoenzimáticas , Técnicas In Vitro , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Mutagênese Sítio-Dirigida , Estadiamento de Neoplasias , Neprilisina/genética , Proteínas Nucleares/genética , Prognóstico , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Estromais/metabolismo , Células Estromais/patologia , Taxa de Sobrevida , Células Tumorais Cultivadas , Proteína 1 Relacionada a Twist/genética , Ensaios Antitumorais Modelo de Xenoenxerto
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...