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1.
JAMA Oncol ; 9(10): 1381-1389, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37561451

RESUMO

Importance: In ERBB2 (formerly HER2)-positive metastatic breast cancer (MBC), combining trastuzumab and pertuzumab with taxane-based chemotherapy is the first line of standard care. Given that trastuzumab plus pertuzumab was proven effective in ERBB2-positive MBC, even without chemotherapy, whether the optimal first-line strategy could be trastuzumab plus pertuzumab alone instead of with chemotherapy is unresolved. Objective: To assess overall survival (OS) at 2 years and progression-free survival (PFS) for patients randomly assigned to receive first-line pertuzumab plus trastuzumab alone or with chemotherapy followed by trastuzumab and emtansine at progression; PFS of second-line trastuzumab and emtansine treatment following trastuzumab plus pertuzumab; and OS and PFS in the ERBB2-enriched and ERBB2-nonenriched subtypes. Design, Setting, and Participants: This was a secondary analysis of a multicenter, open-label, phase 2 randomized clinical trial conducted at 27 sites in France, 20 sites in Switzerland, 9 sites in the Netherlands, and 1 site in Germany. Overall, 210 patients with centrally confirmed ERBB2-positive MBC were randomized between May 3, 2013, and January 4, 2016, with termination of the trial May 26, 2020. Data were analyzed from December 18, 2020, to May 10, 2022. Interventions: Patients randomly received pertuzumab (840 mg intravenously [IV], then 420 mg IV every 3 weeks) plus trastuzumab (8 mg/kg IV, then 6 mg/kg IV every 3 weeks) without chemotherapy (group A) or pertuzumab plus trastuzumab (same doses) with either paclitaxel (90 mg/m2 for days 1, 8, and 15, then every 4 weeks for ≥4 months) or vinorelbine tartrate (25 mg/m2 for first administration followed by 30 mg/m2 on days 1 and 8 and every 3 weeks for ≥4 months) followed by pertuzumab plus trastuzumab maintenance after chemotherapy discontinuation (group B). Main Outcomes and Measures: Overall survival at 24 months by treatment group, PFS for first-line treatment, PFS for second-line treatment, and patient-reported quality of life (QOL). Results: A total of 210 patients were included in the analysis, with a median age of 58 (range, 26-85) years. For group A, 24-month OS was 79.0% (90% CI, 71.4%-85.4%); for group B, 78.1% (90% CI, 70.4%-84.5%). Median PFS with first-line treatment was 8.4 (95% CI, 7.9-12.0) months in group A and 23.3 (95% CI, 18.9-33.1) months in group B. Unlike expectations, OS and PFS did not markedly differ between populations with ERBB2-enriched and ERBB2-nonenriched cancer. Adverse events were less common without chemotherapy, with small QOL improvements from baseline in group A and stable QOL in group B. Conclusions and Relevance: The findings of this secondary analysis of a randomized clinical trial suggest that the chemotherapy-free anti-ERBB2 strategy is feasible without being detrimental in terms of OS. The 50-gene prediction analysis of microarray signature could not help to identify the most appropriate patient population for this approach. Trial Registration: ClinicalTrials.gov Identifier: NCT01835236.

2.
Ann Surg ; 275(6): 1130-1136, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33055589

RESUMO

OBJECTIVE: To assess the impact of surgical technique in regard to morbidity and mortality after neoadjuvant treatment for esophageal cancer. BACKGROUND: The SAKK trial 75/08 was a multicenter phase III trial (NCT01107639) comparing induction chemotherapy followed by chemoradiation and surgery in patients with locally advanced esophageal cancer. METHODS: Patients in the control arm received induction chemotherapy with cisplatin and docetaxel, followed by concomitant chemoradiation therapy with cisplatin, docetaxel, and 45Gy. In the experimental arm, the same regimen was used with addition of cetuximab. After completion of neoadjuvant treatment, patients underwent esophagectomy. The experimental arm received adjuvant cetuximab. Surgical outcomes and complications were prospectively recorded and analyzed. RESULTS: Total of 259 patients underwent esophagectomy. Overall complication rate was 56% and reoperation rate was 15% with no difference in complication rates for transthoracic versus transhiatal resections (56% vs 54%, P = 0.77), nor for video assisted thoracic surgeries (VATS) versus open transthoracic resections (67% vs 55%, P = 0.32). There was a trend to higher overall complication rates in squamous cell carcinoma versus adenocarcinoma (65% vs 51%, P = 0.035), and a significant difference in ARDS in squamous cell carcinoma with 14% versus 2% in adenocarcinoma (P = 0.0002). For patients with involved lymph nodes, a lymph node ratio of ≥0.1 was an independent predictor of PFS (HR 2.5, P = 0.01) and OS (HR 2.2, P = 0.03). CONCLUSIONS: This trial showed no difference in surgical complication rates between transthoracic and transhiatal resections. For patients with involved lymph nodes, lymph node ratio was an independent predictor of progression free survival and overall survival.


Assuntos
Adenocarcinoma , Carcinoma de Células Escamosas , Neoplasias Esofágicas , Adenocarcinoma/patologia , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/terapia , Cetuximab/uso terapêutico , Cisplatino/uso terapêutico , Docetaxel/uso terapêutico , Esofagectomia/métodos , Humanos , Terapia Neoadjuvante/métodos , Estadiamento de Neoplasias , Taxa de Sobrevida , Resultado do Tratamento
3.
BMC Cancer ; 20(1): 166, 2020 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-32111181

RESUMO

BACKGROUND: High rates of venous thromboembolic events (VTEs), mainly in advanced disease, are reported for patients with cancer of the upper gastrointestinal tract (stomach, pancreas) and for treatment with cisplatin. METHODS: Exploratory analysis of VTEs reported as adverse events and serious adverse events in a prospective, randomised, multicentre, multimodal phase III trial according to VTEs reported as adverse events and severe adverse events. Patients with resectable oesophageal cancer (T2N1-3, T3-4aNx) were randomized to 2 cycles of chemotherapy with docetaxel 75 mg/m2, cisplatin 75 mg/m2 followed by chemo-radiotherapy (CRT) and subsequent surgery (control arm) or the same treatment with addition of cetuximab (investigational arm). RESULTS: VTEs occurred in 26 of 300 patients included in the trial, resulting in an incidence rate (IR) of 8.7% [95% CI 5.7-12.4%]. A total of 29 VTEs were reported:13 (45%) VTEs were grade 2, 13 (45%) grade 3 and three (10%) fatal grade 5 events. 72% (21/29) of all VTEs occurred preoperatively (IR 6.7%): 14% (4/29) during chemotherapy and 59% (17/29) during CRT. In multivariable logistic regression only adenocarcinoma (IR 11.1%, 21/189 patients) compared to squamous cell cancer (IR 4.5%, 5/111 patients) was significantly associated with VTE-risk during treatment, OR 2.9 [95%CI 1.0-8.4], p = 0.046. Baseline Khorana risk score was 0 in 73% (19/26), 1-2 in 23% (6/26) and 3 in only 4% (1/26) of patients with VTEs. CONCLUSION: A high incidence of VTEs during preoperative therapy of resectable oesophageal cancer is observed in this analysis, especially in patients with adenocarcinoma. The role of prophylactic anticoagulation during neoadjuvant therapy in resectable esophageal cancer should be further evaluated in prospective clinical trials. According to our data, which are in line with other analysis of VTE-risk in patients with oesophageal cancer patients treated with neoadjuvant cisplatin-based chemotherapy and CRT, prophylactic anticoagluation could be considered balanced against individual bleeding risks, especially in patients with adenocarcinoma. In addition to the established risk factors, oesophageal adenocarcinoma treated with neoadjuvant cisplatin-based therapy may be regarded as a high-risk situation for VTEs. TRIAL REGISTRATION: Registered at clinicaltrials.gov, NCT01107639, on 21 April 2010.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Cetuximab/administração & dosagem , Neoplasias Esofágicas/terapia , Tromboembolia/epidemiologia , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Cetuximab/efeitos adversos , Quimiorradioterapia/efeitos adversos , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Procedimentos Cirúrgicos do Sistema Digestório/efeitos adversos , Docetaxel/administração & dosagem , Docetaxel/efeitos adversos , Neoplasias Esofágicas/patologia , Feminino , Humanos , Incidência , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Tromboembolia/induzido quimicamente , Resultado do Tratamento
4.
Radiat Oncol ; 14(1): 166, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31511012

RESUMO

BACKGROUND: Sarcopenia, the critical depletion of skeletal muscle mass, is an independent prognostic factor in several tumor entities for treatment-related toxicity and survival. In esophageal cancer, there have been conflicting results regarding the value of sarcopenia as prognostic factor, which may be attributed to the heterogeneous patient populations and the retrospective nature of previous studies. The aim of our study was therefore to determine the impact of sarcopenia on prospectively collected specific outcomes in a subgroup of patients treated within the phase III study SAKK 75/08 with trimodality therapy (induction chemotherapy, radiochemotherapy and surgery) for locally advanced esophageal cancer. METHODS: Sarcopenia was assessed by skeletal muscle index at the 3rd lumbar vertebra (L3) in cross-sectional computed tomography scans before induction chemotherapy, before radiochemotherapy and after neoadjuvant therapy in a subgroup of 61 patients from four centers in Switzerland. Sarcopenia was determined by previously established cut-off values (Martin et al., PMID: 23530101) and correlated with prospectively collected outcomes including treatment-related toxicity, postoperative morbidity, treatment feasibility and survival. RESULTS: Using the published cut-off values, the prevalence of sarcopenia increased from 29.5% before treatment to 63.9% during neoadjuvant therapy (p < 0.001). Feasibility of neoadjuvant therapy and surgery was not different in initially sarcopenic and non-sarcopenic patients. We observed in sarcopenic patients significantly increased grade ≥ 3 toxicities during chemoradiation (83.3% vs 52.4%, p = 0.04) and a non-significant trend towards increased postoperative complications (66.7% vs 42.9%, p = 0.16). No difference in survival according to sarcopenia could be observed in this small study population. CONCLUSIONS: Trimodality therapy in locally advanced esophageal cancer is feasible in selected patients with sarcopenia. Neoadjuvant chemoradiation increased the percentage of sarcopenia. Sarcopenic patients are at higher risk for increased toxicity during neoadjuvant radiochemotherapy and showed a non-significant trend to more postoperative morbidity.


Assuntos
Adenocarcinoma/terapia , Quimiorradioterapia/efeitos adversos , Neoplasias Esofágicas/terapia , Carcinoma de Células Escamosas do Esôfago/terapia , Músculo Esquelético/patologia , Terapia Neoadjuvante/efeitos adversos , Sarcopenia/patologia , Adenocarcinoma/patologia , Adulto , Idoso , Terapia Combinada , Estudos Transversais , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/patologia , Esofagectomia/efeitos adversos , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/diagnóstico por imagem , Prognóstico , Sarcopenia/diagnóstico por imagem , Sarcopenia/etiologia , Taxa de Sobrevida , Tomografia Computadorizada por Raios X/métodos
5.
Trials ; 19(1): 667, 2018 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-30514362

RESUMO

BACKGROUND: Complete lymph node removal through conventional axillary dissection (ALND) has been standard treatment for breast cancer patients for almost a century. In the 1990s, however, and in parallel with the advent of the sentinel lymph node (SLN) procedure, ALND came under increasing scrutiny due to its association with significant patient morbidity. Several studies have since provided evidence to suggest omission of ALND, often in favor of axillary radiation, in selected clinically node-negative, SLN-positive patients, thus supporting the current trend in clinical practice. Clinically node-positive patients, by contrast, continue to undergo ALND in many cases, if only for the lack of studies re-assessing the indication for ALND in these patients. Hence, there is a need for a clinical trial to evaluate the optimal treatment for clinically node-positive breast cancer patients in terms of surgery and radiotherapy. The TAXIS trial is designed to fill this gap by examining in particular the value of tailored axillary surgery (TAS), a new technique for selectively removing positive lymph nodes. METHODS: In this international, multicenter, phase-III, non-inferiority, randomized controlled trial (RCT), including 34 study sites from four different countries, we plan to randomize 1500 patients to either receive TAS followed by ALND and regional nodal irradiation excluding the dissected axilla, or receive TAS followed by regional nodal irradiation including the full axilla. All patients undergo adjuvant whole-breast irradiation after breast-conserving surgery and chest-wall irradiation after mastectomy. The main objective of the trial is to test the hypothesis that treatment with TAS and axillary radiotherapy is non-inferior to ALND in terms of disease-free survival of clinically node-positive breast cancer patients in the era of effective systemic therapy and extended regional nodal irradiation. The trial was activated on 31 July 2018 and the first patient was randomized on 7 August 2018. DISCUSSION: Designed to test the hypothesis that TAS is non-inferior to ALND in terms of curing patients and preventing recurrences, yet is significantly superior in reducing patient morbidity, this trial may establish a new worldwide treatment standard in breast cancer surgery. If found to be non-inferior to standard treatment, TAS may significantly contribute to reduce morbidity in breast cancer patients by avoiding surgical overtreatment. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT03513614. Registered on 1 May 2018. www.kofam.ch , ID: NCT03513614 . Registered on 17 June 2018. EudraCT No.: 2018-000372-14.


Assuntos
Neoplasias da Mama/terapia , Excisão de Linfonodo/métodos , Mastectomia Segmentar , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Ensaios Clínicos Fase III como Assunto , Intervalo Livre de Doença , Estudos de Equivalência como Asunto , Europa (Continente) , Feminino , Humanos , Excisão de Linfonodo/efeitos adversos , Excisão de Linfonodo/mortalidade , Metástase Linfática , Mastectomia Segmentar/efeitos adversos , Mastectomia Segmentar/mortalidade , Qualidade de Vida , Radioterapia Adjuvante , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
6.
Lancet ; 386(9998): 1049-56, 2015 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-26275735

RESUMO

BACKGROUND: One of the standard options in the treatment of stage IIIA/N2 non-small-cell lung cancer is neoadjuvant chemotherapy and surgery. We did a randomised trial to investigate whether the addition of neoadjuvant radiotherapy improves outcomes. METHODS: We enrolled patients in 23 centres in Switzerland, Germany and Serbia. Eligible patients had pathologically proven, stage IIIA/N2 non-small-cell lung cancer and were randomly assigned to treatment groups in a 1:1 ratio. Those in the chemoradiotherapy group received three cycles of neoadjuvant chemotherapy (100 mg/m(2) cisplatin and 85 mg/m(2) docetaxel) followed by radiotherapy with 44 Gy in 22 fractions over 3 weeks, and those in the control group received neoadjuvant chemotherapy alone. All patients were scheduled to undergo surgery. Randomisation was stratified by centre, mediastinal bulk (less than 5 cm vs 5 cm or more), and weight loss (5% or more vs less than 5% in the previous 6 months). The primary endpoint was event-free survival. Analyses were done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00030771. FINDINGS: From 2001 to 2012, 232 patients were enrolled, of whom 117 were allocated to the chemoradiotherapy group and 115 to the chemotherapy group. Median event-free survival was similar in the two groups at 12·8 months (95% CI 9·7-22·9) in the chemoradiotherapy group and 11·6 months (8·4-15·2) in the chemotherapy group (p=0·67). Median overall survival was 37·1 months (95% CI 22·6-50·0) with radiotherapy, compared with 26·2 months (19·9-52·1) in the control group. Chemotherapy-related toxic effects were reported in most patients, but 91% of patients completed three cycles of chemotherapy. Radiotherapy-induced grade 3 dysphagia was seen in seven (7%) patients. Three patients died in the control group within 30 days after surgery. INTERPRETATION: Radiotherapy did not add any benefit to induction chemotherapy followed by surgery. We suggest that one definitive local treatment modality combined with neoadjuvant chemotherapy is adequate to treat resectable stage IIIA/N2 non-small-cell lung cancer. FUNDING: Swiss State Secretariat for Education, Research and Innovation (SERI), Swiss Cancer League, and Sanofi.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/terapia , Quimiorradioterapia Adjuvante/métodos , Neoplasias Pulmonares/terapia , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/secundário , Quimiorradioterapia Adjuvante/efeitos adversos , Feminino , Humanos , Neoplasias Pulmonares/patologia , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante/efeitos adversos , Terapia Neoadjuvante/métodos , Estadiamento de Neoplasias , Pneumonectomia/métodos , Análise de Sobrevida , Resultado do Tratamento
7.
J Am Chem Soc ; 135(26): 9743-52, 2013 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-23742167

RESUMO

HIV-1 reverse transcriptase (RT) is a heterodimeric enzyme that converts the genomic viral RNA into proviral DNA. Despite intensive biochemical and structural studies, direct thermodynamic data regarding RT interactions with its substrates are still lacking. Here we addressed the mechanism of action of RT and of non-nucleoside RT inhibitors (NNRTIs) by isothermal titration calorimetry (ITC). Using a new incremental-ITC approach, a step-by-step thermodynamic dissection of the RT polymerization activity showed that most of the driving force for DNA synthesis is provided by initial dNTP binding. Surprisingly, thermodynamic and kinetic data led to a reinterpretation of the mechanism of inhibition of NNRTIs. Binding of NNRTIs to preformed RT/DNA complexes is hindered by a kinetic barrier and NNRTIs mostly interact with free RT. Once formed, RT/NNRTI complexes bind DNA either in a seemingly polymerase-competent orientation or form high-affinity dead-end complexes, both RT/NNRTI/DNA complexes being unable to bind the incoming nucleotide substrate.


Assuntos
Transcriptase Reversa do HIV/antagonistas & inibidores , Transcriptase Reversa do HIV/metabolismo , Inibidores da Transcriptase Reversa/farmacologia , Termodinâmica , Calorimetria , Transcriptase Reversa do HIV/química , Nucleotídeos/química , Nucleotídeos/metabolismo , Polimerização , Inibidores da Transcriptase Reversa/química , Relação Estrutura-Atividade
8.
Nucleic Acids Res ; 38(2): 370-81, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19906720

RESUMO

The C/D box scaRNA2 is predicted to guide specific 2'-O-methylation of U2 snRNA. In contrast to other SCARNA genes, SCARNA2 appears to be independently transcribed. By transient expression of SCARNA2-reporter gene constructs, we have demonstrated that this gene is transcribed by RNA polymerase II and that the promoter elements responsible for its transcription are contained within a 161 bp region upstream of the transcription start site. In mammals, we have identified four cross species conserved promoter elements, a TATA motif, an hStaf/ZNF143 binding site and two novel elements that are required for full promoter activity. Binding of the human hStaf/ZNF143 transcription factor to its target sequence is required for promoter activity, suggesting that hStaf/ZNF143 is a fundamental regulator of the SCARNA2 gene. We also showed that RNA polymerase II continues transcription past the 3'-end of the mature RNA, irrespective of the identity of the Pol II promoter. The 3'-end processing and accumulation are governed by the sole information contained in the scaRNA2 encoding region, the maturation occurring via a particular pathway incompatible with that of mRNA or snRNA production.


Assuntos
RNA/genética , Transcrição Gênica , Sítios de Ligação , Células HeLa , Humanos , Regiões Promotoras Genéticas , RNA/biossíntese , RNA/metabolismo , Processamento de Terminações 3' de RNA , RNA Polimerase II/metabolismo , Transativadores/metabolismo , Pequeno RNA não Traduzido
9.
Viruses ; 2(4): 880-899, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21994659

RESUMO

HIV-1 reverse transcriptase (RT) inhibitors currently used in antiretroviral therapy can be divided into two classes: (i) nucleoside analog RT inhibitors (NRTIs), which compete with natural nucleoside substrates and act as terminators of proviral DNA synthesis, and (ii) non-nucleoside RT inhibitors (NNRTIs), which bind to a hydrophobic pocket close to the RT active site. In spite of the efficiency of NRTIs and NNRTIs, the rapid emergence of multidrug-resistant mutations requires the development of new RT inhibitors with an alternative mechanism of action. Recently, several studies reported the discovery of novel non-nucleoside inhibitors with a distinct mechanism of action. Unlike classical NNRTIs, they compete with the nucleotide substrate, thus forming a new class of RT inhibitors: nucleotide-competing RT inhibitors (NcRTIs). In this review, we discuss current progress in the understanding of the peculiar behavior of these compounds.

10.
Gene ; 401(1-2): 145-53, 2007 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-17707600

RESUMO

The mitochondrial transcription factor A (Tfam) is essential for transcription initiation and replication of mitochondrial DNA. It was previously reported that transcription factors Sp1, NRF-1, NRF-2 were critical for maintaining the normal transcription levels of the mammalian TFAM gene. In this work, investigation of the transcriptional regulation of the human TFAM gene revealed the presence of two cross-species conserved binding sites for the transcription factor hStaf/ZNF143. By using promoter binding assays, transient expression of mutant TFAM reporter gene constructs and chromatin immunoprecipitation experiments, we provided insight into the involvement of hStaf/ZNF143 in promoter activity. Furthermore, we reported the identification of two other functionally important elements. Altogether, our data led to the conclusion that the promoter of the human TFAM gene harbors a complex organization with at least six transcriptional regulatory elements.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/fisiologia , Proteínas Mitocondriais/metabolismo , Transativadores/fisiologia , Fatores de Transcrição/fisiologia , Sequência de Aminoácidos , Animais , Sítios de Ligação , Células COS , Chlorocebus aethiops , Imunoprecipitação da Cromatina , Análise por Conglomerados , Proteínas de Ligação a DNA/genética , Expressão Gênica , Genes Reporter , Humanos , Luciferases/metabolismo , Proteínas Mitocondriais/genética , Dados de Sequência Molecular , Mutação , Regiões Promotoras Genéticas , Ligação Proteica , Homologia de Sequência de Aminoácidos , Transativadores/genética , Transativadores/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transfecção , beta-Galactosidase/metabolismo
11.
Nucleic Acids Res ; 35(10): 3453-64, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17478512

RESUMO

BubR1 is a key protein mediating spindle checkpoint activation. Loss of this checkpoint control results in chromosomal instability and aneuploidy. The transcriptional regulation of the cell cycle regulated human BUB1B gene, which encodes BubR1, was investigated in this report. A minimal BUB1B gene promoter containing 464 bp upstream from the translation initiation codon was sufficient for cell cycle regulated promoter activity. A pivotal role for transcription factor hStaf/ZNF143 in the expression of the BUB1B gene was demonstrated through gel retardation assays, transient expression of mutant BUB1B promoter-reporter gene constructs and chromatin immunoprecipitation assay. Two phylogenetically conserved hStaf/ZNF143-binding sites (SBS) were identified which are indispensable for BUB1B promoter activity. In addition, we found that the domain covering the transcription start sites contains conserved boxes homologous to initiator (Inr), cell cycle dependent (CDE) and cell cycle genes homology regions (CHR) elements. Mutations within the CDE and CHR elements led to diminished cell cycle regulation of BUB1B transcription. These results demonstrate that BUB1B gene transcription is positively regulated by hStaf/ZNF143, a ubiquitously expressed factor, and that the CDE-CHR tandem element was essential for G2/M-specific transcription of the BUB1B gene.


Assuntos
Proteínas de Ligação a DNA/fisiologia , Regiões Promotoras Genéticas , Proteínas Quinases/genética , Transativadores/fisiologia , Ativação Transcricional , Região 5'-Flanqueadora , Animais , Sequência de Bases , Sítios de Ligação , Células COS , Ciclo Celular/genética , Linhagem Celular , Chlorocebus aethiops , Elementos de DNA Transponíveis , Proteínas de Ligação a DNA/metabolismo , Drosophila/citologia , Drosophila/genética , Humanos , Dados de Sequência Molecular , Mutação , Proteínas Quinases/biossíntese , Proteínas Serina-Treonina Quinases , Transativadores/metabolismo , Sítio de Iniciação de Transcrição
12.
J Biol Chem ; 281(52): 39953-62, 2006 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-17092945

RESUMO

Staf was originally identified as the transcriptional activator of Xenopus tRNA(Sec) and small nuclear (sn) RNA-type genes. Recently, transcription of seven human (h) protein coding genes was reported to be activated by the human ortholog hStaf/ZNF143. Here we have used a combined in silico and biochemical approach to identify 1175 conserved hStaf/ZNF143-binding sites (SBS) distributed in 938 promoters of four mammalian genomes. The SBS shows a significant positional preference and occurs mostly within 200 bp upstream of the transcription start site. Chromatin immunoprecipitation assays with 295 of the promoters established that 90% contain bona fide SBS. By extrapolating the values of this mapping to the full sizes of the mammalian genomes, we can infer the existence of at least 2500 SBS distributed in 2000 promoters. This unexpected large number strongly suggests that SBS constitutes one of the most widespread transcription factor-binding sites in mammalian promoters. Furthermore, we demonstrated that the presence of the SBS alone is sufficient to direct expression of a luciferase reporter gene, suggesting that hStaf/ZNF143 can recruit per se the transcription machinery.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Genoma Humano , Regiões Promotoras Genéticas/fisiologia , Transativadores/genética , Transativadores/metabolismo , Motivos de Aminoácidos/genética , Animais , Sequência de Bases , Sítios de Ligação/genética , Células COS , Chlorocebus aethiops , Biologia Computacional , Sequência Conservada , Ilhas de CpG/genética , Proteínas de Ligação a DNA/fisiologia , Variação Genética , Humanos , Camundongos , Dados de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Transativadores/fisiologia
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