RESUMO
Telomerase activity in cancer cells is dependent on the transcriptional regulation of the human telomerase reverse transcriptase (hTERT) gene, encoding the catalytic subunit of human telomerase. We have shown previously that HTLV-1 basic leucine zipper (HBZ), a viral regulatory protein encoded by the human retrovirus, human T-cell leukemia virus, type 1 (HTLV-1) cooperates with JunD to enhance hTERT transcription in adult T-cell leukemia (ATL) cells. Menin, the product of the tumor-suppressor MEN-1 gene, also interacts with JunD, represses its transcriptional activity and downregulates telomerase expression. The main objective of this study was to examine how menin and HBZ get involved in the regulation of hTERT transcription. In this study, we report that JunD and menin form a repressor complex of hTERT transcription in HBZ-negative cells. Conversely, in HBZ-positive cells, the formation of a JunD/HBZ/menin ternary complex and the recruitment of p300 histone acetyl transferase activity by HBZ lead to a decreased activity of the JunD-menin suppressor unit that correlates with the activation of hTERT transcription. Silencing HBZ or menin expression in ATL cells confirms that these proteins are differentially involved in telomerase regulation. These results propose that HBZ, by impeding the tumor-suppressor activity of menin, functions as a leukemogenic cofactor to upregulate gene transcription and promote JunD-mediated leukemogenesis.
Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Proteína p300 Associada a E1A/metabolismo , Regulação Neoplásica da Expressão Gênica , Leucemia de Células T/patologia , Proteínas Proto-Oncogênicas c-jun/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Telomerase/genética , Proteínas Virais/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/antagonistas & inibidores , Fatores de Transcrição de Zíper de Leucina Básica/genética , Western Blotting , Proliferação de Células , Imunoprecipitação da Cromatina , Proteína p300 Associada a E1A/genética , Células HeLa , Humanos , Imunoprecipitação , Leucemia de Células T/genética , Leucemia de Células T/metabolismo , Regiões Promotoras Genéticas/genética , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-jun/genética , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Proteínas dos Retroviridae , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Telomerase/metabolismo , Transcrição Gênica , Células Tumorais Cultivadas , Proteínas Virais/antagonistas & inibidores , Proteínas Virais/genéticaRESUMO
Based on results of clinical trials, completion ALND (cALND) is frequently not performed for patients with breast conservation therapy and one or two involved sentinel nodes (SN) by micro- or macro-metastases. However, there were limitations despite a conclusion of non-inferiority for cALND omission. No trial had included patients with SN macro-metastases and total mastectomy or with >2 SN macro-metastases. The aim of the study was too analyze treatment delivered and pathologic results of patients included in SERC trial. SERC trial is a multicenter randomized non-inferiority phase-3 trial comparing no cALND with cALND in cT0-1-2, cN0 patients with SN ITC (isolated tumor cells) or micro-metastases or macro-metastases, mastectomy or breast conservative surgery. We randomized 1855 patients, 929 to receive cALND and 926 SLNB alone. No significant differences in patient's and tumor characteristics, type of surgery, and adjuvant chemotherapy (AC) were observed between the two arms. Rates of involved SN nodes by ITC, micro-metastases, and macro-metastases were 5.91%, 28.12%, and 65.97%, respectively, without significant difference between two arms for all criteria. In multivariate analysis, two factors were associated with higher positive non-SN rate: no AC versus AC administered after ALND (OR = 3.32, p < 0.0001) and >2 involved SN versus ≤2 (OR = 3.45, p = 0.0258). Crude rates of positive NSN were 17.62% (74/420) and 26.45% (73/276) for patient's eligible and non-eligible to ACOSOG-Z0011 trial. No significant differences in patient's and tumor characteristics and treatment delivered were observed between the two arms. Higher positive-NSN rate was observed for patients with AC performed after ALND (17.65% for SN micro-metastases, 35.22% for SN macro-metastases) in comparison with AC administered before ALND.
RESUMO
The aim of this study was to assess the social validity and document the implementation of a psychoeducational program designed to support parents after their child's diagnosis, from both parents' and professionals' perspectives. A complete version (five workshops and five individual follow-ups) and a shortened version (five workshops only) of the program were evaluated. Parents filled in satisfaction questionnaires after every workshop and at the end of the program. Professionals who facilitated the program filled in a specially designed questionnaire to rate the quality of the program and of its implementation, the fidelity of implementation and the parents' responsiveness. In addition, video recordings of the workshops allowed an objective assessment of the fidelity of implementation. Attendance rates were high; parents were satisfied and felt they had made progress. Professionals evaluated positively the quality of the program and of its implementation, and felt parents were responsive. However, minor adaptations had to be made. The program has good social validity, which allowed easy and satisfying implementation, but it does require some flexibility. Overall, this study provides useful insight on the implementation process that may help clinical services to use this evidence-based program effectively.
RESUMO
We report a multiresistant Enterobacter cloacae outbreak in an intensive care unit, associated with mattresses and with antibacterial-treated and vapour-permeable polyurethane synthetic mattress covers of therapeutic beds.
Assuntos
Leitos/microbiologia , Farmacorresistência Bacteriana Múltipla , Enterobacter cloacae , Infecções por Enterobacteriaceae/etiologia , Unidades de Terapia Intensiva , Leitos/efeitos adversos , Infecção Hospitalar/etiologia , Infecção Hospitalar/prevenção & controle , Enterobacter cloacae/isolamento & purificação , Infecções por Enterobacteriaceae/prevenção & controle , Contaminação de Equipamentos/prevenção & controle , HumanosRESUMO
The aetiology of post-polio syndrome may involve persistence of poliovirus (PV) in the CNS. PV persists in the CNS of infected paralysed mice for over a year after the acute phase of paralytic poliomyelitis. However, infectious PV particles cannot be recovered from homogenates of CNS from paralysed mice after the acute phase of disease, indicating that PV replication is restricted. To identify the molecular mechanism by which PV replication is limited, PV RNA synthesis was analysed by estimating the relative level of genomic (plus-strand) and complementary (minus-strand) PV RNA in the CNS of persistently infected mice. PV RNA replication decreased during the 6 months following onset of paralysis, due mainly to inhibition of plus-strand RNA synthesis. Thus, restriction of PV RNA synthesis may contribute to persistence by limiting virus replication in the mouse CNS. Interestingly, viral RNA replication was similarly inhibited in neuroblastoma IMR-32 cell cultures persistently infected with PV. This in vitro model thus shows that cellular factors play a role in the inhibition of viral RNA synthesis.
Assuntos
Neurônios/virologia , Poliomielite/virologia , Poliovirus/genética , RNA Viral/biossíntese , Animais , Feminino , Camundongos , Reação em Cadeia da PolimeraseRESUMO
Most individuals exposed to hepatitis C virus (HCV) become chronically infected and are predisposed to liver disease. The mechanisms underlying viral persistence and disease progression are unknown. A role for the HCV NS5A protein in viral replication and interferon resistance has been demonstrated. To identify mechanisms affected by NS5A, we analyzed the gene expression of Huh7 cells expressing NS5A and control cells using oligonucleotide microarrays. A set of 103 genes (43 up-regulated, 60 down-regulated) whose expression was modified by at least twofold was selected. These included genes involved in cell adhesion and motility, calcium homeostasis, lipid transport and metabolism, and genes regulating immune responses. The finding of modulated expression of genes related to the TGF-beta superfamily and liver fibrosis was observed. Interestingly, both the tumor necrosis factor and lymphotoxin beta receptors were down-regulated by NS5A. Similar data were obtained following expression of four NS5A mutants obtained from patients who were not responsive or were sensitive to interferon therapy. Through computational analysis, we determined that 39 of the 43 genes up-regulated by NS5A contained one or more nuclear factor kappaB (NF-kappaB) binding sites within their promoter region. Using the Gibbs sampling method, we also detected enrichment of NF-kappaB consensus binding sites in the upstream regions of the 43 coexpressed genes. Activation of NF-kappaB by NS5A was subsequently demonstrated in luciferase reporter assays. Adenovirus-mediated expression of IkappaBalpha reverted NS5A mediated up-regulation of gene expression. In conclusion, this study suggests a role of NS5A and NF-kappaB in HCV pathogenesis and related liver disease. Supplementary material for this article can be found on the HEPATOLOGY website (http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html).
Assuntos
Regulação Viral da Expressão Gênica , Hepatite C/etiologia , Peptídeos e Proteínas de Sinalização Intracelular , Análise de Sequência com Séries de Oligonucleotídeos , Regiões Promotoras Genéticas , Transdução de Sinais/fisiologia , Proteínas não Estruturais Virais/fisiologia , Sequência de Aminoácidos , Sítios de Ligação , Cálcio/metabolismo , Carcinoma Hepatocelular/genética , Proteínas de Transporte/fisiologia , Perfilação da Expressão Gênica , Humanos , Interferon-alfa/uso terapêutico , Interleucina-1/fisiologia , Proteínas de Ligação a TGF-beta Latente , Metabolismo dos Lipídeos , Neoplasias Hepáticas/genética , Dados de Sequência Molecular , NF-kappa B/metabolismo , Fator de Crescimento Transformador beta/fisiologia , Fator de Crescimento Transformador beta1RESUMO
There is evidence for an inhibition of interferon-alpha antiviral activity by the hepatitis C viral protein, NS5A. To identify the mechanisms through which NS5A blocks interferon activity, we compared the gene expression profile of interferon-treated Huh7 cells, stably expressing NS5A with control, using microarrays. Following interferon treatment, 50 genes were up-regulated by at least twofold in control clones, whereas induction of 9 of the 50 genes was significantly reduced in NS5A-expressing clones. The strongest effect of NS5A on interferon response was observed for the OAS-p69 gene. Remarkably, Huh7 cells expressing NS5A showed an up-regulation of interleukin-8. Up-regulation of interleukin-8 was also observed upon transient expression of NS5A mutants isolated from patients responsive or resistant to interferon therapy. Addition of interleukin-8 to Huh7 cells inhibited the antiviral activity of interferon and, similarly to NS5A, reduced the induction by interferon-alpha of selective genes including OAS-p69. Our findings provide a mechanism for NS5A-mediated interferon resistance.