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1.
World J Surg ; 41(2): 449-456, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27671014

RESUMO

BACKGROUND: Single-incision laparoscopy (SIL) and natural orifice translumenal endoscopic surgery (NOTES) aim at reducing surgical access trauma. To monitor the introduction of emerging technologies, the Swiss Association for Laparo- and Thoracoscopic Surgeons launched a database in 2010. The current status of SIL and NOTES in Switzerland is reported, and the techniques are compared. METHODS: The number and type of procedures, surgeon experience, their impressions of performance, conversion, and complications between 2010 and 2015 are described. A survey was used to acquire additional data not included in the registry. RESULTS: Nine centers included 650 procedures. Cholecystectomy (55 %) and sigmoidectomy (26 %) were most prevalent in both techniques. The number of active centers declined from 9 to 2 during the study period. The frequencies of taught procedures were 4 and 43 % for SIL and NOTES (p < 0.001), and surgeon self-estimated impression of performance was perfect in 50 and 89 %, respectively (p < 0.0001). Conversions in total were 3.6 and 5.7 %, respectively, and 1.1 % to open for both techniques. Morbidity was 5 % in SIL and 2.7 % in NOTES, with 0.8 % access-related complications in NOTES and none in SIL (p = 0.29). Of laparoscopic cholecystectomy, sigmoidectomy, and right hemicolectomy, 11.4 and 15.6 % of cases were operated using SIL or NOTES, respectively (p < 0.0001). CONCLUSIONS: Although in selected specialized centers, a considerable proportion of patients were treated using novel techniques, a fading interest of the surgical community in SIL and NOTES was observed. The proportion of SIL and NOTES procedures taught is insufficient and calls for improvement.


Assuntos
Laparoscopia/estatística & dados numéricos , Cirurgia Endoscópica por Orifício Natural/estatística & dados numéricos , Procedimentos Cirúrgicos Operatórios/estatística & dados numéricos , Conversão para Cirurgia Aberta/estatística & dados numéricos , Feminino , Humanos , Complicações Intraoperatórias/epidemiologia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Sistema de Registros , Procedimentos Cirúrgicos Operatórios/métodos , Suíça/epidemiologia
2.
Surg Endosc ; 25(11): 3531-4, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21638185

RESUMO

BACKGROUND: Surgical site infection (SSI) in patients who underwent colorectal surgery is a common complication associated with increased morbidity and costs. The aim of this study was to assess risk factors for SSI in laparoscopic sigmoid resection for benign disease. METHODS: Using a multicenter database of the Swiss Association of Laparoscopic and Thoracoscopic Surgery, we prospectively identified 4,488 patients who underwent laparoscopic colorectal surgery between 1995 and 2008; of these, 2,571 patients who underwent sigmoid resection for benign disease were included. Uni- and multivariate analyses were used to determine risk factors for SSI. RESULTS: The incidence of SSI was 3.5% (90/2,571). Among SSI patients, incisional superficial infections were found in 71%, incisional deep infections in 22%, and organ-space infections in 7%. Patients' age, underlying disease, and surgeons' experience had no impact on SSI. Multivariate analyses showed that operation time >240 min (odds ratio [OR] 1.7; 95% confidence interval [CI] 1.0-2.8), BMI ≥ 27 kg/m(2) (OR 2.3 [1.3-4.5]), organ lesions (OR 7.9 [2.0-31.8]), and male gender (OR 2.3 [1.2-4.5]) were significant risk factors for SSI. Reoperations in the SSI group were significantly more frequent than in the Non-SSI group (30% vs. 3%; p < 0.001). SSI was associated with a significantly longer median hospital stay (15 days, range = 2-69 vs. 8 days, range = 1-69; p < 0.001) and higher mortality rate (2.2% vs. 0.4%; p = 0.019). CONCLUSION: Significant risk factors for SSI were operation time > 240 min, BMI ≥ 27 kg/m(2), organ lesions, and male gender. SSI was significantly associated with more reoperations, longer hospital stay, and higher mortality rate.


Assuntos
Índice de Massa Corporal , Colo Sigmoide/cirurgia , Laparoscopia , Doenças do Colo Sigmoide/cirurgia , Infecção da Ferida Cirúrgica/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Complicações Intraoperatórias , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Fatores de Risco , Adulto Jovem
3.
Surg Endosc ; 24(6): 1451-5, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20039072

RESUMO

BACKGROUND: Incisional hernia is a common complication after liver transplantation. The current study evaluated incidence and risk factors for incisional hernia and compared laparoscopic and open hernia repair in terms of feasibility and outcome. METHODS: A cohort of 225 patients was prospectively investigated. The median follow-up period was 61 months (range, 6-186 months). The study cohort had 31 patients who underwent open repair and 13 who underwent laparoscopic repair. RESULTS: Incisional hernia, found in 57 patients (25%), had occurred after a median of 17 months (range, 5-138 months). The significant risk factors were male gender (p = 0.001) and body mass index (BMI) greater than 25 kg/m(2) (p = 0.002). A trend toward a lower recurrence rate (15% vs 35%; p = 0.28) and fewer surgical complications (15% vs 19%; p = 0.99) was found in the laparoscopic group. CONCLUSIONS: Incisional hernia is a frequent complication after liver transplantation. Associated risk factors are male gender and a BMI greater than 25 kg/m(2). Laparoscopic hernia repair for such patients is feasible and safe.


Assuntos
Hérnia Ventral/cirurgia , Laparoscopia/métodos , Transplante de Fígado/efeitos adversos , Procedimentos de Cirurgia Plástica/métodos , Adulto , Idoso , Estudos de Viabilidade , Feminino , Seguimentos , Hérnia Ventral/epidemiologia , Hérnia Ventral/etiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Estudos Prospectivos , Fatores de Risco , Fatores Sexuais , Técnicas de Sutura , Suíça/epidemiologia , Fatores de Tempo , Resultado do Tratamento
4.
Ann Surg Oncol ; 16(10): 2862-74, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19655202

RESUMO

BACKGROUND: Papillary or follicular thyroid carcinomas exhibit a relatively benign course. Hence, long-term follow-up studies with well-defined disease stages and treatment details are needed to evaluate treatment strategies. METHODS: Patients who underwent complete resection of well-differentiated thyroid carcinoma (WDTC) confined to the thyroid gland between 1972 and 1990 identified from a prospective database were assessed. Follow-up was performed by interview, review of patient charts, and analysis of the Death Registry. Primary endpoints were overall survival (OS) and disease-specific survival (DSS). Review of histology was performed and extent of thyroid resection, postoperative therapy, and recognized prognostic factors but not lymphadenectomy were evaluated. RESULTS: Of 2,867 patients, 213 had complete resection of WDTC confined to the thyroid gland. Follow-up was completed in 166 patients with median age 54.2 (range, 20-85) years, and median follow-up of 27.2 (range, 15.6-34.5) years. The 10- and 20-year OS was 71 and 55%, respectively. DSS at 10 and 20 years was 81 and 69%, respectively, and correlated with age, histology, tumor size, radio-iodide ablation (RIA), and external beam irradiation (EBR) treatment. No patient died of WDTC more than 18 years after resection. Total or near-total thyroidectomy without lymphadenectomy was not superior to partial thyroidectomy. In multivariate analysis for DSS, age was the dominant factor, which correlated with histology. CONCLUSION: After a median follow-up of 27 years, about one-third of patients died of WDTC. Age, histology and postoperative therapy but not extent of thyroid resection determined DSS.


Assuntos
Adenocarcinoma Folicular/cirurgia , Carcinoma Papilar/cirurgia , Diferenciação Celular , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia , Adenocarcinoma Folicular/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Papilar/patologia , Feminino , Seguimentos , Humanos , Excisão de Linfonodo , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Estudos Prospectivos , Estudos Retrospectivos , Taxa de Sobrevida , Neoplasias da Glândula Tireoide/patologia , Resultado do Tratamento , Adulto Jovem
5.
Ann Surg ; 248(6): 1060-6, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19092351

RESUMO

OBJECTIVE: To evaluate the effects of a single preoperative dose of steroid on thyroidectomy outcomes. BACKGROUND: Nausea, pain, and voice alteration frequently occur after thyroidectomy. Because steroids effectively reduce nausea and inflammation, a preoperative administration of steroids could improve these thyroidectomy outcomes. METHODS: Seventy-two patients (men = 20, women = 52) undergoing thyroidectomy for benign disease were included in this randomized, controlled, 2 armed (group D: 8 mg dexamethasone, n = 37; group C: 0.9% NaCl, n = 35), double-blinded study (clinical trial number NCT00619086). Anesthesia, surgical procedures, antiemetics, and analgesic treatments were standardized. Nausea (0-3), pain (visual analog scale), antiemetic and analgesic requirements, and digital voice recording were documented before and 4, 8, 16, 24, 36, and 48 hours after surgery. Patients were followed-up 30 days after hospital discharge. RESULTS: Baseline characteristics were similar among the 2 treatment groups. Nausea was pronounced in the first 16 hours postoperatively (scores were <0.3 and 0.8-1.0 for group D and C, respectively (P = 0.005)), and was significantly lower in group D compared with group C during the observation period (P = 0.001). Pain diminished within 48 hours after surgery (visual analog scale 20 and 35 in group D and C, respectively (P = 0.009)). Antiemetic and analgesic requirements were also significantly diminished. Changes in voice mean frequency were less prominent in the dexamethasone group compared with the placebo group (P = 0.015). No steroid-related complications occurred. CONCLUSION: A preoperative single dose of steroid significantly reduced nausea, vomiting, and pain, and improved postoperative voice function within the first 48 hours (most pronounced within 16 hours) after thyroid resection; this strategy should be routinely applied in thyroidectomies.


Assuntos
Dexametasona/administração & dosagem , Glucocorticoides/administração & dosagem , Dor Pós-Operatória/prevenção & controle , Náusea e Vômito Pós-Operatórios/prevenção & controle , Cuidados Pré-Operatórios , Doenças da Glândula Tireoide/cirurgia , Voz , Adulto , Idoso , Idoso de 80 Anos ou mais , Método Duplo-Cego , Feminino , Rouquidão/epidemiologia , Rouquidão/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Tireoidectomia , Fatores de Tempo , Adulto Jovem
6.
Clin Cancer Res ; 13(20): 6032-9, 2007 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-17947465

RESUMO

PURPOSE: Activation of the double-stranded RNA-activated protein kinase (PKR) leads to the induction of various pathways including the down-regulation of translation through phosphorylation of the eukaryotic translation initiation factor 2alpha (eIF-2alpha). There have been no reports to date about the role of PKR in radiation sensitivity. EXPERIMENTAL DESIGN: A clonogenic survival assay was used to investigate the sensitivity of PKR mouse embryo fibroblasts (MEF) to radiation therapy. 2-Aminopurine (2-AP), a chemical inhibitor of PKR, was used to inhibit PKR activation. Nuclear factor-kappaB (NF-kappaB) activation was assessed by electrophoretic mobility shift assay (EMSA). Expression of PKR and downstream targets was examined by Western blot analysis and immunofluorescence. RESULTS: Ionizing radiation leads to dose- and time-dependent increases in PKR expression and function that contributes to increased cellular radiation resistance as shown by clonogenic survival and terminal nucleotidyl transferase-mediated nick end labeling (TUNEL) apoptosis assays. Specific inhibition of PKR with the chemical inhibitor 2-AP restores radiation sensitivity. Plasmid transfection of the PKR wild-type (wt) gene into PKR(-/-) MEFs leads to increased radiation resistance. The protective effect of PKR to radiation may be mediated in part through NF-kappaB and Akt because both NF-kappaB and Akt are activated after ionizing radiation in PKR+/+ but not PKR-/- cells. CONCLUSIONS: We suggest a novel role for PKR as a mediator of radiation resistance modulated in part through the protective effects of NF-kappaB and Akt activation. The modification of PKR activity may be a novel strategy in the future to overcome radiation resistance.


Assuntos
Fibroblastos/metabolismo , Regulação Enzimológica da Expressão Gênica , NF-kappa B/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , eIF-2 Quinase/metabolismo , Animais , Densitometria , Relação Dose-Resposta à Radiação , Fator de Iniciação 2 em Eucariotos/metabolismo , Marcação In Situ das Extremidades Cortadas , Camundongos , Modelos Biológicos , Fosforilação , Plasmídeos/metabolismo , Radiação Ionizante , Transfecção
7.
Ther Umsch ; 65(6): 329-34, 2008 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-18622956

RESUMO

Because recurrent adenocarcinoma of the colon and rectum (CRC) can still be treated with acceptable 5-year survival rates, tumor surveillance plays an important role. Early detection of recurrent disease from CRC allows for effective treatment with intention for cure. This is why, in 2007, an interdisciplinary group modified the popular "FAGAS" criteria, a proposition for surveillance after curative resection of colorectal cancer. Proposed are the 3-monthly follow-up of the tumor marker CEA (carcino embryonic antigen), which, in case of lower sigmoid or rectal cancer, would be completed by rectosigmoidoscopy and endosonography every 6 months. As a major change liver sonography is now proposed to be replaced by annual thoraco-abdominal CT scan. Colonoscopy within the first year after resection has its place in the surveillance due to a high rate of metachronous secondary tumors missed in the initial endoscopy. Once completed it needs not to be repeated for at least 3 years. Only in cases where early stage CRC was been completely resected no schematic surveillance must take place.


Assuntos
Assistência ao Convalescente/métodos , Neoplasias Colorretais/cirurgia , Recidiva Local de Neoplasia/diagnóstico , Segunda Neoplasia Primária/diagnóstico , Complicações Pós-Operatórias/diagnóstico , Biomarcadores Tumorais/sangue , Antígeno Carcinoembrionário/sangue , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Endossonografia , Humanos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/secundário , Neoplasias Hepáticas/terapia , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/terapia , Estadiamento de Neoplasias , Segunda Neoplasia Primária/mortalidade , Segunda Neoplasia Primária/terapia , Equipe de Assistência ao Paciente , Complicações Pós-Operatórias/mortalidade , Complicações Pós-Operatórias/terapia , Prognóstico , Sigmoidoscopia , Análise de Sobrevida , Tomografia Computadorizada por Raios X
8.
FEBS Lett ; 581(5): 989-94, 2007 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-17316623

RESUMO

NDRG1 is a hypoxia-inducible protein, whose modulated expression is associated with the progression of human cancers. Here, we reveal that NDRG1 is markedly upregulated in the cytoplasm and on the membrane in human hepatocellular carcinoma (HCC). We demonstrate further that hypoxic stress increases the cytoplasmic expression of NDRG1 in vitro, but does not result in its localization on the plasma membrane. However, grown within an HCC-xenograft in vivo, cells express NDRG1 in the cytoplasm and on the plasma membrane. In conclusion, hypoxia is a potent inducer of NDRG1 in HCCs, albeit requiring additional stimuli within the tumour microenvironment for its recruitment to the membrane.


Assuntos
Carcinoma Hepatocelular/metabolismo , Proteínas de Ciclo Celular/metabolismo , Hipóxia/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neoplasias Hepáticas/metabolismo , Sequência de Aminoácidos , Animais , Carcinoma Hepatocelular/genética , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Citoplasma/metabolismo , Expressão Gênica , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/química , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Técnicas In Vitro , Peptídeos e Proteínas de Sinalização Intracelular/química , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neoplasias Hepáticas/genética , Masculino , Camundongos , Camundongos Nus , Dados de Sequência Molecular , Transplante de Neoplasias , Estrutura Terciária de Proteína , Transplante Heterólogo
9.
Cancer Res ; 62(8): 2239-43, 2002 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-11956076

RESUMO

Adenoviral-mediated overexpression of the melanoma differentiation-associated gene 7 (Ad-mda7) induces apoptosis in a wide range of cancer cells, although themechanism is not well understood. We report that Ad-mda7 induces andactivates the double-stranded RNA-dependent protein kinase (PKR), which leads to phosphorylation of the alpha subunit of eukaryotic translation initiation factor 2 (eIF-2alpha) and the induction of apoptosis in lung cancer cells. Treatment with 2-aminopurine (2-AP), a serine/threonine kinase inhibitor, inhibits PKR activation, eIF2alpha phosphorylation, and apoptosis induction by Ad-mda7. Additionally, PKR null but not wild-type fibroblasts are resistant to Ad-mda7-induced apoptosis. These results suggest that the activation of PKR and its downstream targets may be a critical pathway for Ad-mda7-mediated apoptosis.


Assuntos
Apoptose/fisiologia , Substâncias de Crescimento/genética , Interleucinas , Neoplasias Pulmonares/patologia , eIF-2 Quinase/biossíntese , 2-Aminopurina/farmacologia , Adenoviridae/genética , Apoptose/genética , Proteínas de Ligação a DNA/metabolismo , Indução Enzimática , Inibidores Enzimáticos/farmacologia , Técnicas de Transferência de Genes , Genes Supressores de Tumor , Humanos , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/genética , Fosforilação , Fatores de Transcrição/metabolismo , Células Tumorais Cultivadas , Regulação para Cima , eIF-2 Quinase/antagonistas & inibidores , eIF-2 Quinase/genética
10.
Mol Cancer Ther ; 4(11): 1710-6, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16275992

RESUMO

Overexpression of the transcription factor E2F-1 induces apoptosis in a variety of carcinoma cells and inactivates murine double minute protein 2, a factor associated with poor prognosis in soft tissue sarcomas. We have shown previously that the double-stranded RNA-activated protein kinase PKR plays an important role in mediating this apoptotic response in carcinoma cells to E2F-1. We sought to evaluate the potential of E2F-1 gene therapy in soft tissue sarcomas and to study the involvement of PKR in the response to E2F-1 overexpression in mesenchymal cells. A replication-deficient adenovirus carrying the E2F-1 gene (Ad5E2F) was used to induce E2F-1 overexpression in the p53 mutated leiomyosarcoma cell line, SKLMS-1. Western blot analysis confirmed E2F-1 overexpression and up-regulation of the antiapoptotic factor Bcl-2 48 hours following infection with Ad5E2F. Apoptosis in Ad5E2F-treated cells was confirmed by fluorescence-activated cell sorting analysis and by poly(ADP-ribose) polymerase cleavage and DNA fragmentation assays. Vector-dependent up-regulation of PKR correlated with the amount of Ad5E2F-induced apoptosis. In vivo treatment of SKLMS-1 tumor-bearing BALB/c mice with intratumoral injections of Ad5E2F at a dose of 2 x 10(10) viral particles resulted in significant inhibition in tumor growth compared with control-treated animals (P < 0.016). Complete disappearance of all tumors was seen in two of seven mice in the Ad5E2F-treated animals. Immunohistochemical analysis of tumor specimens showed overexpression of E2F-1 and up-regulation of PKR in Ad5E2F-treated tumors. These findings show that adenovirus-mediated overexpression of E2F-1 results in up-regulation of PKR and significant growth suppression of leiomyosarcomas in vivo. Taken together, these data suggest that E2F-1 gene therapy and PKR modulation might be a promising treatment strategy for these tumors that are highly resistant to conventional therapies.


Assuntos
Apoptose , Fator de Transcrição E2F1/genética , Regulação Neoplásica da Expressão Gênica , Terapia Genética/métodos , Leiomiossarcoma/tratamento farmacológico , Leiomiossarcoma/patologia , Regulação para Cima , eIF-2 Quinase/biossíntese , Adenoviridae/genética , Animais , Western Blotting , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Separação Celular , Fragmentação do DNA , Fator de Transcrição E2F1/uso terapêutico , Citometria de Fluxo , Vetores Genéticos , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos BALB C , Transplante de Neoplasias , Poli(ADP-Ribose) Polimerases/metabolismo , Prognóstico , RNA de Cadeia Dupla/química , Proteínas Recombinantes/genética , Sarcoma/tratamento farmacológico , Fatores de Tempo , Proteína Supressora de Tumor p53/metabolismo
11.
Oncogene ; 21(41): 6278-88, 2002 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-12214268

RESUMO

The transcription factor E2F-1 induces cell cycle progression at the G1/S checkpoint, and deregulation of E2F-1 provokes apoptosis in a wide variety of malignant cells. To date only p14(ARF) and p73, a p53 homologue, have been identified as E2F-1-inducible genes capable of mediating an apoptotic response. Here we show that adenovirus-mediated E2F-1 overexpression in cancer cells induces expression and autophosphorylation of the double-stranded RNA-dependent protein kinase PKR leading to phosphorylation of its downstream target, the alpha-subunit of the eukaryotic translation initiation factor 2 (eIF-2alpha) and to apoptotic cell death. This PKR-dependent apoptosis occurs in cell lines with mutated p53 and in cell lines with mutated p53 and p73, and is significantly reduced by the chemical inhibition of PKR activation. Further, PKR(-/-) mouse embryo fibroblasts, but not PKR(+/+) mouse embryo fibroblasts, demonstrate significant resistance to E2F-1-induced apoptosis. We conclude that an important pathway of E2F-1-mediated apoptosis is dependent on PKR activation and does not require p53 or p73.


Assuntos
Apoptose/genética , Fatores de Transcrição/genética , eIF-2 Quinase/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ligação a DNA , Fatores de Transcrição E2F , Fator de Transcrição E2F1 , Ativação Enzimática/genética , Regulação da Expressão Gênica , Genes Supressores de Tumor , Genes p53 , Humanos , Proteínas Nucleares , Fosforilação , Fatores de Transcrição/metabolismo , Células Tumorais Cultivadas , Proteína Tumoral p73 , Proteínas Supressoras de Tumor , eIF-2 Quinase/metabolismo
12.
Surgery ; 138(2): 261-8, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16153435

RESUMO

BACKGROUND: Tumor necrosis factor alpha (TNF-alpha) is a cytokine with direct antitumor activity. Clinical trials with TNF-alpha have been limited because of the severe side effects of systemic administration. Gene therapy with an adenoviral vector allows delivery of high local doses of TNF-alpha. Activation of protein kinase R (PKR) has been implicated as a general transducer of apoptosis in response to a variety of different stimuli including TNF-alpha. We, therefore, evaluated the role of PKR in Ad-TNF-alpha-induced apoptosis in esophageal cancer cells. METHODS: A tetracycline-responsive adenoviral vector was used to transfect the TNF-alpha gene (Ad-TNF-alpha) into human esophageal cancer cell lines Bic1, Seg1 and TT, as well as in transformed PKR(+/+) and PKR(-/-) early-passage mouse embryo fibroblasts. Ad-luciferase, Ad-Bak, and mock infection with phosphate buffered saline solution were used as controls. Gene expression was determined by Western blot analysis. Apoptosis was detected by propidium iodide staining and fluorescence-activated cell sorter analysis. RESULTS: Overexpression of TNF-alpha in the lysate was evident in all cell lines treated with Ad-TNF-alpha. Treatment with Ad-TNF-alpha was associated with PKR upregulation and induction of apoptosis. Inhibition of TNF-alpha expression by tetracycline resulted in downregulation of PKR and decreased apoptosis. Transduction of PKR(+/+) and PKR(-/-) mouse embryo fibroblasts with Ad-TNF-alpha demonstrated that Ad-TNF-alpha-induced apoptosis was mediated in part through a PKR-dependent process. CONCLUSIONS: These results suggest that Ad-TNF-alpha-mediated apoptosis in esophageal cancer cell lines is dependent in part on PKR upregulation. Strategies to enhance PKR upregulation may allow increased Ad-TNF-alpha antitumoral activity in the treatment of esophageal cancer.


Assuntos
Adenocarcinoma/terapia , Neoplasias Esofágicas/terapia , Terapia Genética/métodos , Fator de Necrose Tumoral alfa/genética , eIF-2 Quinase/metabolismo , Adenoviridae/genética , Apoptose , Linhagem Celular Tumoral , Meios de Cultivo Condicionados , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Fosforilação , RNA de Cadeia Dupla/metabolismo , Tetraciclinas/farmacologia , Regulação para Cima
13.
Am J Pharmacogenomics ; 4(3): 189-98, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15174900

RESUMO

The is a double-stranded RNA-activated protein kinase (PKR) has been largely investigated for its key role in viral host defense. Although best characterized by its function in mediating the antiviral and antiproliferative effects of interferon (IFN), PKR is also implicated in transcriptional regulation, cell differentiation, signal transduction, and tumor suppression. However, recent findings identifying PKR as an important effector of apoptosis have led to an increased interest in PKR modulation as an antitumor strategy. PKR can either be up-regulated through direct induction by the transcription factor E2F-1, or it can be activated through direct protein-protein interactions with the melanoma differentiation-associated gene-7 (MDA7, IL-24). Additionally, the intracellular formation of double-stranded RNA by transfection with antisense RNA complementary to tumor-specific RNA sequences can induce PKR activation and apoptosis selective to these tumor cells. The growing application of viral vector-based gene therapies and oncolytic, replicating viruses that must elude viral defense in order to be effective, has also drawn attention to PKR. Oncolytic viruses, like the attenuated herpes simplex virus R3616, the vesicular stomatitis virus, or reovirus, specifically replicate in tumor cells only because the viral host defense in the permissive cells is suppressed. In this article we review the role of PKR as an effector of apoptosis and a target for tumor treatment strategies and discuss the potential of PKR-modifying agents to treat patients with cancer. Targeted gene therapy against cancer can be approached by activation of PKR with the down-regulation of protein synthesis and induction of apoptosis, or by suppression of PKR with the propagation of oncolytic virus. Since the PKR pathway can be modified by many routes, antitumor therapies combining oncolytic virus, gene therapies, and chemotherapy with PKR modifiers are likely to emerge in the near future as therapeutic options in the treatment of patients with cancer.


Assuntos
Ativação Enzimática/genética , Terapia Genética , Neoplasias/genética , Neoplasias/terapia , eIF-2 Quinase/genética , eIF-2 Quinase/metabolismo , Animais , Apoptose/fisiologia , Inibidores Enzimáticos/uso terapêutico , Humanos , eIF-2 Quinase/antagonistas & inibidores
15.
PLoS One ; 7(3): e33433, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22479397

RESUMO

Sirtuins and hypoxia-inducible transcription factors (HIF) have well-established roles in regulating cellular responses to metabolic and oxidative stress. Recent reports have linked these two protein families by demonstrating that sirtuins can regulate the activity of HIF-1 and HIF-2. Here we investigated the role of SIRT1, a NAD+-dependent deacetylase, in the regulation of HIF-1 activity in hypoxic conditions. Our results show that in hepatocellular carcinoma (HCC) cell lines, hypoxia did not alter SIRT1 mRNA or protein expression, whereas it predictably led to the accumulation of HIF-1α and the up-regulation of its target genes. In hypoxic models in vitro and in in vivo models of systemic hypoxia and xenograft tumor growth, knockdown of SIRT1 protein with shRNA or inhibition of its activity with small molecule inhibitors impaired the accumulation of HIF-1α protein and the transcriptional increase of its target genes. In addition, endogenous SIRT1 and HIF-1α proteins co-immunoprecipitated and loss of SIRT1 activity led to a hyperacetylation of HIF-1α. Taken together, our data suggest that HIF-1α and SIRT1 proteins interact in HCC cells and that HIF-1α is a target of SIRT1 deacetylase activity. Moreover, SIRT1 is necessary for HIF-1α protein accumulation and activation of HIF-1 target genes under hypoxic conditions.


Assuntos
Carcinoma Hepatocelular/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias Hepáticas Experimentais/metabolismo , Sirtuína 1/metabolismo , Ativação Transcricional , Animais , Benzamidas/farmacologia , Western Blotting , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Hipóxia Celular , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Células Hep G2 , Humanos , Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Neoplasias Hepáticas Experimentais/genética , Neoplasias Hepáticas Experimentais/patologia , Camundongos , Camundongos Knockout , Camundongos Nus , Naftalenos/farmacologia , Naftóis/farmacologia , Ligação Proteica , Pirimidinonas/farmacologia , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sirtuína 1/antagonistas & inibidores , Sirtuína 1/genética , Transplante Heterólogo , Carga Tumoral/efeitos dos fármacos
16.
Oncol Lett ; 1(1): 203-207, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22966283

RESUMO

Endometrial cancer is one of the more frequent and most lethal gynaecological cancer types. Since it occurs more frequently in elderly and overweight patients, a pre-operative staging method would be beneficial. The growth of solid neoplasms is always accompanied by neovascularisation. Tumour endothelial markers (TEMs) are a group of recently described endothelial cell surface markers that appear to be specific to neoplastic tissue. This study aimed to investigate the potential usefulness of TEM assessment in the endometrium by comparing the transcriptional expression of TEMs in the normal endometrium with endometroid adenocarcinoma tissue. Tissues were lysed and the RNA was extracted, assessed and reverse transcribed in one batch. Real-time quantitative PCR was performed for TEM-1, -2, -6, -7, -7r and -8. GAPDH, ß-actin and ribosomal protein L13A (RPL13A) were used as control genes. TEM-8 showed the highest expression level in all of the groups. TEM-1 showed higher expression levels in the normal endometrium than in the tumour tissues. For the remaining TEMs, we found a higher expression in the cancer samples than in the normal endometria. Statistical significance of this difference was achieved for TEM-1, -2 and-7. No clear correlation was noted between the tumour stage and the level of TEM-1, -6 and -8 expression. Apart from TEM-6, the highest expression in FIGO I cancer stages was noted in the remaining TEMs. Our results showed that for most of these tumour endothelial markers, gene expression was slightly higher in the endometrial carcinoma tissue samples than in the endometrium of normal cycling women. However, with the possible exception of TEM-8 and -6, absolute expression levels were generally low, indicating that most TEMs may only be specifically expressed in a restricted number of cancer types (e.g., colorectal). Therefore, TEMs may not be useful in the context of endometrial cancer.

17.
Mol Cancer Res ; 7(6): 916-22, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19491197

RESUMO

The Hypermethylated in Cancer 1 (HIC1) gene encodes a zinc finger transcriptional repressor that cooperates with p53 to suppress cancer development. We and others recently showed that HIC1 is a transcriptional target of p53. To identify additional transcriptional regulators of HIC1, we screened a set of transcription factors for regulation of a human HIC1 promoter reporter. We found that E2F1 strongly activates the full-length HIC1 promoter reporter. Promoter deletions and mutations identified two E2F responsive elements in the HIC1 core promoter region. Moreover, in vivo binding of E2F1 to the HIC1 promoter was shown by chromatin immunoprecipitation assays in human TIG3 fibroblasts expressing tamoxifen-activated E2F1. In agreement, activation of E2F1 in TIG3-E2F1 cells markedly increased HIC1 expression. Interestingly, expression of E2F1 in the p53(-/-) hepatocellular carcinoma cell line Hep3B led to an increase of endogenous HIC1 mRNA, although bisulfite genomic sequencing of the HIC1 promoter revealed that the region bearing the two E2F1 binding sites is hypermethylated. In addition, endogenous E2F1 induced by etoposide treatment bound to the HIC1 promoter. Moreover, inhibition of E2F1 strongly reduced the expression of etoposide-induced HIC1. In conclusion, we identified HIC1 as novel E2F1 transcriptional target in DNA damage responses.


Assuntos
Fator de Transcrição E2F1/genética , Fatores de Transcrição Kruppel-Like/genética , Sequência de Bases , Sítios de Ligação , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Metilação de DNA , Fator de Transcrição E2F1/metabolismo , Etoposídeo/farmacologia , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Fatores de Transcrição Kruppel-Like/biossíntese , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Dados de Sequência Molecular , Regiões Promotoras Genéticas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Alinhamento de Sequência , Transcrição Gênica , Regulação para Cima/efeitos dos fármacos
18.
J Gastrointest Surg ; 13(10): 1781-90, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19565301

RESUMO

AIM: The mTOR-inhibitor rapamycin has shown antitumor activity in various tumors. Bedside observations have suggested that rapamycin may be effective as a treatment for colorectal carcinomatosis. METHODS: We established an orthotopic syngenic model by transplanting CT26 peritoneal tumors in Balb/C mice and an orthotopic xenograft model by transplanting SW620 peritoneal tumors in nu/nu mice. Expression levels of tissue inhibitor of matrix-metalloproteinases 1 (TIMP-1) in the tumor and serum was determined by enzyme-linked immunosorbent assay. RESULTS: Rapamycin significantly suppressed growth of syngenic and xenografted peritoneal tumors. The effect was similar with intraperitoneal or oral rapamycin administration. Tumor suppression was further enhanced when rapamycin was combined with 5-fluorouracil and/or oxaliplatin. The combination treatment showed no acute toxicity. TIMP-1 serum levels correlated well (CC = 0.75; P < 0.01) with rapamycin treatment. CONCLUSIONS: Rapamycin suppressed advanced stage colorectal cancer, even with oral administration. Combining rapamycin with current chemotherapy regimens significantly increased antitumor efficacy without apparent toxicity. The treatment efficacy correlated with serum TIMP-1 levels, suggesting its potential as a surrogate marker in future clinical trials.


Assuntos
Antineoplásicos/administração & dosagem , Neoplasias Colorretais/tratamento farmacológico , Fluoruracila , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Animais , Linhagem Celular Tumoral , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Fluoruracila/administração & dosagem , Humanos , Camundongos , Compostos Organoplatínicos/administração & dosagem , Oxaliplatina , Neoplasias Peritoneais/tratamento farmacológico , Sirolimo/administração & dosagem , Resultado do Tratamento , Ensaios Antitumorais Modelo de Xenoenxerto
19.
J Gastrointest Surg ; 12(10): 1724-9, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18726133

RESUMO

INTRODUCTION: Natural orifice transluminal endoscopic surgery (NOTES) is a multidisciplinary surgical technique. If conventional endoscopic instrumentation can be easily mastered, surgeons with laparoscopic experience could head NOTES interventions. MATERIALS AND METHODS: Thirty individuals were tested for endoscopic dexterity. Group 1 included seven gastroenterologists, group 2 included 12 laparoscopically experienced surgeons lacking endoscopic experience, and group 3 included 11 interns who had no hands-on endoscopic or surgical experience. Each individual repeated an easy (T1), medium (T2), and difficult (T3) task ten times with endoscopic equipment on a NOTES skills-box. RESULTS: Group 3 had significantly poorer performances for all three tasks compared to the other groups. No significant differences were seen between groups 1 and 2 for T1 and T2. The initial T3 performance of group 1 was better than that of group 2, but their performance after repetition was not statistically different. Groups 2 and 3 improved significantly with repetition, and group 2 eventually performed as well as group 1. CONCLUSIONS: The data indicate that laparoscopic surgeons quickly learned to handle the endoscopic equipment. This suggests that a lack of endoscopic experience does not handicap laparoscopic surgeons when performing endoscopic tasks. Based on their knowledge of anatomy and the complication management acquired during surgical education, surgeons are well equipped to take the lead in interdisciplinary NOTES collaborations.


Assuntos
Endoscopia/estatística & dados numéricos , Gastroenterologia/estatística & dados numéricos , Cirurgia Geral/estatística & dados numéricos , Adulto , Competência Clínica , Educação de Pós-Graduação em Medicina , Feminino , Humanos , Internato e Residência , Masculino , Desempenho Psicomotor
20.
J Gastrointest Surg ; 12(9): 1571-6, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18521693

RESUMO

INTRODUCTION: The incidence of duodenal diverticula (DD) found at autopsy may be as high as 22%. Perforation is the least frequent but also the most serious complication. This case series gives an overview of the management of this rare entity. METHODS: This study is a case series of eight patients treated for symptomatic DD. RESULTS: Two patients had a perforated DD. One perforation was in segments III-IV, which to our knowledge is the first published case; the other perforation was in segment II. A segmental duodenectomy was performed in the first patient and a pylorus-preserving duodeno-pancreatectomy (pp-Whipple) in the second. A third patient with chronic complaints and recurring episodes of fever required an excision of the DD. In a fourth patient with biliary and pancreatic obstruction, a pp-Whipple was carried out, and a DD was discovered as the underlying cause. Four patients (one small perforation, one hemorrhage, and two recurrent cholangitis/pancreatitis caused by a DD) were treated conservatively. CONCLUSIONS: Symptomatic DD and, in particular, perforations are rare, encompass diagnostic challenges, and may require technically demanding surgical or endoscopic interventions. The diagnostic value of forward-looking gastroduodenoscopy in this setting seems limited. If duodenoscopy is performed at all, the use of a side-viewing endoscope is mandatory.


Assuntos
Divertículo/diagnóstico , Divertículo/cirurgia , Duodenopatias/diagnóstico , Duodenopatias/cirurgia , Perfuração Intestinal/cirurgia , Idoso , Colangiopancreatografia Retrógrada Endoscópica/métodos , Duodenoscopia/métodos , Feminino , Seguimentos , Humanos , Perfuração Intestinal/diagnóstico , Laparotomia/métodos , Masculino , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/terapia , Medição de Risco , Estudos de Amostragem , Índice de Gravidade de Doença , Resultado do Tratamento
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