Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
1.
ANZ J Surg ; 92(9): 2167-2173, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35916436

RESUMO

BACKGROUND: Groove pancreatitis (GP) is an underrecognised subtype of chronic pancreatitis, focally affecting the area between the duodenum and pancreatic head. It most commonly affects males between 40 and 50 years of age with a history of alcohol misuse. Patients most commonly complain of abdominal pain and vomiting. Due to its focal nature, it is a potentially surgically treatable form of chronic pancreatitis. We report results of patients surgically treated for groove pancreatitis followed by a literature review of patient outcomes post resection. METHODS: A retrospective chart review of patients with histopathologically confirmed GP post-surgical resection at the Princess Alexandra Hospital and Greenslopes Private Hospital in Brisbane, Australia was conducted between 2013 and 2020. Diagnosis was confirmed histologically when Brunner gland hyperplasia and chronic inflammation/fibrosis were found within the pancreaticoduodenal interface. Preoperative and postoperative symptoms were analysed along with complications. Additionally, a systematic review on outcomes of patients undergoing pancreaticoduodenectomy (PD) for GP was performed from three databases. RESULTS: Eight patients underwent surgery for GP. Elimination of preoperative symptoms was achieved in five of the eight patients. Major complications included one take back to theatre for pancreatic leak. Our literature review found complete resolution of pain and vomiting in 80% of GP patients after PD. CONCLUSION: Optimal management of GP begins with early recognition. Symptoms from GP are likely to respond well to surgical intervention. We advocate for aggressive surgical resection in a patient with a high index of suspicion for GP.


Assuntos
Pancreatite Crônica , Erros de Diagnóstico , Fibrose , Humanos , Masculino , Pancreaticoduodenectomia/métodos , Pancreatite Crônica/diagnóstico , Pancreatite Crônica/patologia , Pancreatite Crônica/cirurgia , Estudos Retrospectivos , Vômito
2.
Clin Podiatr Med Surg ; 38(1): 99-110, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33220747

RESUMO

The induced membrane technique is a simple, effective, and reproducible treatment method for segmental bone defects. It is a 2-stage approach that requires eventual autologous bone graft to manage the deficit. The first stage requires debridement of all nonviable tissue while preserving a healthy soft tissue envelope. A polymethylmethacrylate is implanted between the osseous segments to maintain length. The osseous defect can be stabilized internally or externally. During the second stage, a vascularized induced membrane is formed and produces multiple growth factors. The induced membrane technique is a valuable option for limb salvage in cases of segmental bone defects.


Assuntos
Reação a Corpo Estranho , Fraturas Ósseas/cirurgia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Membranas/crescimento & desenvolvimento , Membranas/metabolismo , Lesões dos Tecidos Moles/cirurgia , Autoenxertos , Regeneração Óssea , Osso Esponjoso/transplante , Desbridamento , Humanos , Salvamento de Membro/métodos
5.
Transl Androl Urol ; 9(6): 3025-3035, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33457276

RESUMO

Radical prostatectomy (RP) is a common treatment choice for localized prostate cancer. While there is increasing utilisation of robotic assisted RP in some centres, open RP (ORP) remains well established and commonly performed in many parts of the world. The goals of modern ORP are to remove the prostate en-bloc with negative surgical margins, while minimising blood loss and preserving urinary continence and erectile function. We present a technical review of ORP incorporating contemporary techniques for control of the deep venous complex, additional haemostatic measures, nerve-sparing and vesicourethral reconstruction.

6.
BMJ Case Rep ; 12(11)2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31776148

RESUMO

A 49-year-old man presented with a 2-week history of gradual onset progressively worsening left upper quadrant pain. Ten months prior, he had a laparoscopic roux-en-Y gastric bypass (LRYGBP) for severe gastro-oesophageal reflux disease and obesity. On examination, his abdomen was not distended and was soft to palpation. The haemoglobin, white cell count, liver function test, lipase and lactate were normal. An abdominal CT scan demonstrated swirl sign. Given the suspicion of internal herniation, laparoscopy was performed demonstrating only partial closure of the jejuno-jejunal mesodefect resulting in herniation of the small bowel alimentary limb. Internal herniation should be considered as a differential diagnosis in all patients with previous LRYGBP and unexplained abdominal pain, nausea or vomiting. If closure of a mesodefect is to be attempted, a running, braided, non-absorbable suture should be used as a purse-string to avoid small defects with subsequent weight and mesenteric fat loss following bariatric surgery.


Assuntos
Derivação Gástrica/métodos , Herniorrafia/métodos , Doenças do Jejuno/cirurgia , Laparoscopia , Complicações Pós-Operatórias/cirurgia , Técnicas de Fechamento de Ferimentos , Abdome , Derivação Gástrica/efeitos adversos , Hérnia/etiologia , Humanos , Doenças do Jejuno/etiologia , Laparoscopia/efeitos adversos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia
7.
BMJ Case Rep ; 12(10)2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31586954

RESUMO

Small bowel diaphragm disease (SBDD) is characterised by circumferential lesions of short length (<5 mm), causing intrinsic stenosis of the small bowel lumen. A 63-year-old women with a history of long-term non-steroidal anti-inflammatory use, presented with a 12-month history of intermittent episodes of colicky abdominal pain, nausea and vomiting. Her only past surgery was a laparoscopic hysterectomy. Abdominal CT demonstrated an area of thickening in the mid small bowel, however a diagnostic laparoscopy failed to demonstrate adhesions or any external abnormality. A capsule endoscope did not progress beyond the mid small bowel at the site of a suspected diaphragm. The patient underwent a laparotomy and using the retained capsule as a marker, the area of bowel affected by SBDD was identified. With an ageing population and the widespread use of non-steroidalanti-inflammatory drugs, general surgeons may see an increase in the incidence of SBDD.


Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Doenças do Íleo/diagnóstico , Obstrução Intestinal/diagnóstico , Dor Abdominal , Anastomose Cirúrgica , Endoscopia por Cápsula , Diagnóstico Diferencial , Feminino , Humanos , Doenças do Íleo/induzido quimicamente , Doenças do Íleo/diagnóstico por imagem , Doenças do Íleo/cirurgia , Obstrução Intestinal/induzido quimicamente , Obstrução Intestinal/diagnóstico por imagem , Obstrução Intestinal/cirurgia , Laparotomia , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X
8.
BMJ Case Rep ; 12(8)2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31420438

RESUMO

Biliary colic is a pain in the right upper quadrant or epigastrium thought to be caused by functional gallbladder spasm from a temporary obstructing stone in the gallbladder neck, cystic duct or common bile duct. A 56-year-old man presented with frequent episodes of typical biliary colic. At initial laparoscopy, the gallbladder was absent from its anatomic location. Further inspection revealed a left-sided gallbladder (LSGB), suspended from liver segment 3. Preoperative ultrasound, the most common imaging modality for symptomatic gallstones, has a low positive predictive value for detecting LSGB (2.7%). Laparoscopic cholecystectomy (LC) was delayed to attain additional imaging. A magnetic resonance cholangiopancreatography demonstrated the gallbladder left of the falciform ligament with the cystic duct entering the common hepatic duct from the left. The patient underwent an elective LC 8 weeks later. The critical view of safety is paramount to safe surgical dissection and could be safely achieved for LSGB.


Assuntos
Colecistectomia Laparoscópica/métodos , Doenças da Vesícula Biliar/cirurgia , Vesícula Biliar/anormalidades , Vesícula Biliar/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade
9.
BMJ Case Rep ; 12(7)2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31266754

RESUMO

An 81-year-old man presented to medical services with pelvic pain and evolving urinary retention over 3 months. The patient was found to have a tense glans and penile shaft with surrounding induration consistent with malignant priapism. The extent of the induration included the suprapubic region, scrotum, left iliac region and left flank. A CT scan demonstrated an enhancing, pedunculated lesion arising from the anterior bladder wall measuring 30×31×20 mm. There were multiple enlarged left inguinal lymph nodes. Core biopsies of the subcutaneous tissue on the anterior abdominal wall demonstrated plasmacytoid urothelial carcinoma. The majority of patients with plasmacytoid variant of transitional cell carcinoma will present with >stage 3 bladder disease.


Assuntos
Carcinoma de Células de Transição/diagnóstico por imagem , Carcinoma de Células de Transição/patologia , Neoplasias Penianas/secundário , Priapismo/diagnóstico por imagem , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Neoplasias da Bexiga Urinária/patologia , Idoso de 80 Anos ou mais , Biópsia , Carcinoma de Células de Transição/complicações , Humanos , Masculino , Priapismo/etiologia , Tomografia Computadorizada por Raios X/métodos , Bexiga Urinária/diagnóstico por imagem , Neoplasias da Bexiga Urinária/complicações
10.
BMJ Case Rep ; 12(6)2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31229969

RESUMO

A 35-year-old man presented to a regional hospital after being kicked by a horse in the right upper quadrant. He was transferred to our hepatobiliary unit with bile peritonitis 8 days post trauma. Laparoscopic cholecystectomy and intraoperative cholangiography were performed, demonstrating distal common bile duct (CBD) obstruction with contrast extravasation from the distal duct. The CBD was drained with a T-tube via laparotomy. On postoperative day 14, T-tube cholangiography demonstrated no extravasation of contrast from the distal CBD and minor stricturing with eventual duodenal drainage. The T-tube was clamped and 5 weeks later, the patient represented with peri-T-tube bile leakage and right upper quadrant pain. A T-tube cholangiogram confirmed a complex distal CBD stricture. Two attempts at ERCP with intent of stenting the stricture were unsuccessful. The patient underwent an end to side Roux-en-Y choledochojejunostomy and was discharged home 4 days postoperatively on simple analgesia.


Assuntos
Ductos Biliares Extra-Hepáticos/lesões , Coledocostomia/métodos , Drenagem/métodos , Peritonite/patologia , Ferimentos não Penetrantes/patologia , Ferimentos não Penetrantes/terapia , Adulto , Animais , Comportamento Animal , Ductos Biliares Extra-Hepáticos/fisiopatologia , Colecistectomia Laparoscópica , Casco e Garras , Cavalos , Humanos , Laparoscopia , Masculino , Peritonite/terapia , Resultado do Tratamento
11.
J Gastrointest Surg ; 23(8): 1694-1700, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31197695

RESUMO

BACKGROUND: Acute pancreatitis (AP) is one of the most common general acute surgical presentations. Current recommendations are that idiopathic acute pancreatitis (IAP) should account for no more than 20% of AP cases. Some studies suggest gallbladder microlithiasis is the aetiology in up to 75% of IAP patients. Endoscopic ultrasound (EUS) has been reported to be effective in the detection of microlithiasis and choledocholithiasis as well as pancreatic parenchymal, ductal and ampullary disorders. The aims of this study were to evaluate the usefulness of EUS in establishing aetiology in IAP patients and to assess if there is a role for EUS in the selection criteria for laparoscopic cholecystectomy to treat a potential biliary cause in IAP patients. METHODS: A systematic review following PRISMA guideline was performed to gather data on patients with IAP undergoing EUS for further investigation. Three databases (MEDLINE, PubMed, and EMBASE) were searched to 28 July 2018. RESULTS: Our systematic review included 28 studies, comprising 1850 patients with an initial diagnosis of IAP prior to having EUS. Diagnosis of a potential aetiology or associated pancreatic pathology was established in 1095 (62%, p < 0.001) of cases. A biliary aetiology (microlithiasis or choledocholithiasis) was found in 37%. Chronic pancreatitis and associated pancreatic findings (dilated pancreatic duct, pancreatic duct stricture or stone) were found in 21%. Pancreatic neoplasms were found in 6%. Of the patients who had identifiable biliary pathology on EUS that proceeded to cholecystectomy, 2% had a recurrence of AP during a mean follow-up period of 20.5 months. CONCLUSIONS: There is a likely role for the routine use of EUS in the assessment of patients with IAP. The routine use of EUS may decrease the proportion of cases with a diagnosis of IAP. EUS may provide better selection criteria for laparoscopic cholecystectomy in patients with an initial diagnosis of IAP.


Assuntos
Endossonografia/métodos , Pâncreas/diagnóstico por imagem , Pancreatite/diagnóstico , Doença Aguda , Humanos
12.
J Trauma Acute Care Surg ; 86(5): 896-901, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31008893

RESUMO

BACKGROUND: Extrahepatic bile duct injuries (EHBDIs) are a rare consequence of blunt abdominal trauma. The purpose of this study was to establish mechanisms of injury, clinical indicators of EHBDI following blunt trauma (both with investigative modalities and intraoperatively), method and timing of injury detection, and definitive treatment options. METHODS: A systematic review was performed to gather data on patients with an EHBDI secondary to blunt trauma. Three databases (MEDLINE, PubMed, and EMBASE) were searched to July 19, 2018. RESULTS: Our systematic review included 51 studies, compromising a study population of 66 patients with EHBDIs sustained from blunt trauma. The three most common injuries included complete transection of the suprapancreatic common bile duct (29%, n = 19), complete transection of the intrapancreatic common bile duct (23%, n = 15) and partial laceration of the left hepatic duct (20%, n = 13). Of the hemodynamically stable group managed nonoperatively (n = 23), mean timing postinjury to diagnosis of EHBDI was 11 days. An EHBDI was recognized at initial laparotomy in 87% (n = 13) of hemodynamically stable patients. An EHBDI was recognized at initial laparotomy in 57% (n = 8) of hemodynamically unstable patients. CONCLUSION: The EHBDIs are a rare yet serious consequence of blunt trauma. To establish a timely diagnosis and limit complications of missed injuries, a heightened awareness is required by the attending surgeon with particular attention to subtle yet important clinical indicators. These vary depending on the hemodynamic stability of the patient and decision to manage injuries conservatively or surgically on presentation. LEVEL OF EVIDENCE: Systematic review, level III.


Assuntos
Ductos Biliares Extra-Hepáticos/lesões , Ferimentos não Penetrantes/complicações , Humanos , Ferimentos não Penetrantes/diagnóstico
13.
ANZ J Surg ; 89(11): 1392-1397, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30836441

RESUMO

BACKGROUND: A left-sided gallbladder (LSGB) is a rare anatomical anomaly that is often not discovered until surgery. Two cases of LSGB managed with laparoscopic cholecystectomy (LC) stimulated this systematic review. The aims of this study were in LSGB to define the rate of pre-operative detection, variations in biliary anatomy, laparoscopic techniques employed and outcomes of surgery for symptomatic gallstones. METHODS: A systematic review was performed using Preferred Reporting Items for Systematic reviews and Meta-Analyses principles. RESULTS: Fifty-three studies with 112 patients of which 90 (80.4%) had symptomatic gallstones. Pre-operative imaging was performed in 108 patients (96.4%) with an LSGB reported on imaging in 32 (29.6%) patients. The remainder of LSGB were discovered at surgery. Ultrasound detected an LSGB in three (2.7%) patients. Five variants of cystic union with the common hepatic duct (CHD) were identified. The most common (67.8%) was union on the right side of the CHD after a hairpin bend anterior to the CHD. A cholecystectomy for gallstone disease was performed in 90 patients, 23.3% open and 76.7% LC. Common variations in LC technique were different port site placement and techniques related to the falciform ligament to improve exposure. Common bile duct injury occurred in four (4.4%) patients. CONCLUSION: LSGB is a rare anatomical variation that in patients with symptomatic gallstones is usually discovered at surgery. Cholecystectomy is associated with a higher incidence of common bile duct injury.


Assuntos
Colecistectomia Laparoscópica/efeitos adversos , Doenças da Vesícula Biliar/diagnóstico por imagem , Vesícula Biliar/anormalidades , Cálculos Biliares/cirurgia , Colecistectomia Laparoscópica/métodos , Ducto Colédoco/lesões , Vesícula Biliar/diagnóstico por imagem , Vesícula Biliar/cirurgia , Doenças da Vesícula Biliar/epidemiologia , Doenças da Vesícula Biliar/patologia , Ducto Hepático Comum/diagnóstico por imagem , Humanos , Incidência , Período Perioperatório/estatística & dados numéricos
14.
BMJ Case Rep ; 12(1)2019 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-30674499

RESUMO

A 57-year-old man presented with a 6-month history of pelvic fullness. He had no lower urinary tract symptoms or altered bowel habits. On examination, there was a non-tender pelvic mass which extended from the pubic symphysis to the level of the umbilicus. CT scan of the abdomen demonstrated a 22×11×11 cm cystic mass arising from the pelvis extending into the midline and superiorly to the umbilicus. Other than raised carcinoembryonic antigen of 7.6 ng/mL (<5.0), the remainder of his blood test were unremarkable. Flexible cystoscopy demonstrated a convex deformity of the bladder wall in keeping with the compression and displacement as seen on the CT. The patient underwent an open excision of the cystic structure (urachal remnant), partial cystectomy, partial excision of anterior abdominal wall and pelvic lymphadenectomy. A check cystogram performed 12 days following the initial operation was unremarkable.


Assuntos
Parede Abdominal/cirurgia , Cistadenocarcinoma Mucinoso/diagnóstico por imagem , Cistadenocarcinoma Mucinoso/cirurgia , Úraco/anormalidades , Úraco/cirurgia , Parede Abdominal/diagnóstico por imagem , Parede Abdominal/patologia , Assistência ao Convalescente , Antígeno Carcinoembrionário/análise , Cistadenocarcinoma Mucinoso/metabolismo , Cistadenocarcinoma Mucinoso/ultraestrutura , Cistectomia/métodos , Cistoscopia/métodos , Humanos , Excisão de Linfonodo/métodos , Masculino , Pessoa de Meia-Idade , Doenças Raras , Tomografia Computadorizada por Raios X/métodos , Resultado do Tratamento , Úraco/diagnóstico por imagem , Úraco/patologia , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Neoplasias da Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/cirurgia
15.
J Travel Med ; 25(1)2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29924349

RESUMO

Background: Medical tourism has witnessed significant growth in recent years. The emerging trend towards international travel for cosmetic surgical interventions has not previously been reviewed. The current review aims to critically address the scale and impact of cosmetic surgical tourism and to delineate the complication profile of this form of medical tourism. Methods: Articles published in the English language on the PubMed database that were relevant to surgical tourism and the complications of elective surgical procedures abroad were examined. Reference lists of articles identified were further scrutinized. The search terms used included combinations of 'surgery abroad', 'cosmetic surgery abroad', 'cosmetic surgery tourism', 'cosmetic surgery complications' and 'aesthetic tourism'. Results: This article critically reviews the epidemiology of cosmetic surgical tourism and its associated economic factors. Surgical complications of selected procedures, including perioperative complications, are described. The implications for travel medicine practice are considered and recommendations for further research are proposed. Conclusion: This narrative literature review focuses on the issues affecting travellers who obtain cosmetic surgical treatment overseas. There is a lack of focus in the travel medicine literature on the non-surgery-related morbidity of this special group of travellers. Original research exploring the motivation and pre-travel preparation, including the psychological counselling, of cosmetic surgical tourists is indicated.


Assuntos
Técnicas Cosméticas/estatística & dados numéricos , Turismo Médico/estatística & dados numéricos , Segurança do Paciente/estatística & dados numéricos , Cirurgia Plástica/estatística & dados numéricos , Atitude Frente a Saúde , Técnicas Cosméticas/economia , Custos de Cuidados de Saúde , Humanos , Turismo Médico/economia , Complicações Pós-Operatórias/epidemiologia , Cirurgia Plástica/economia , Viagem , Medicina de Viagem
17.
Foot Ankle Spec ; 10(6): 560-566, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28874067

RESUMO

The sural flap procedure is a versatile technique that can be used to cover many types of defects about the lower extremity. The management of soft tissue defects of the lower extremity with underlying osteomyelitis is difficult. The goal for any of these patients is to create a biomechanically stable foot for weight-bearing purposes with no continued infection. Data were gathered using multiple databases from the years 2000 to 2016. Data were compiled looking at the number of subjects, age, comorbidities, number of complications, number of failures, and average flap size of complications/failures. A total of 110 patients were gathered using 5 separate articles. Twenty-two of the 110 patients had short-term complications. Flap failure was seen in 9/110 patients. A significant difference was noticed in flap size between flap failure and complication groups and nonfailure groups. The average flap size of patients who had some form of complication or failure was 51.87 cm2 in size. The average graft size for patients without complications during their recovery was 36.54 cm2. Within our study, the failure rate of 8.9% and complication rate of 13.7% are consistent with previous reports on sural perforator flaps. Last, with regard to the effect of flap size, there were significant differences between patients with a successful outcome and those who experienced complications or failures. LEVELS OF EVIDENCE: Therapeutic, Level III: Systematic review.


Assuntos
Traumatismos da Perna/cirurgia , Retalho Miocutâneo/transplante , Osteomielite/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Lesões dos Tecidos Moles/cirurgia , Feminino , Traumatismos do Pé/diagnóstico , Traumatismos do Pé/cirurgia , Rejeição de Enxerto , Sobrevivência de Enxerto , Humanos , Escala de Gravidade do Ferimento , Traumatismos da Perna/diagnóstico , Masculino , Retalho Miocutâneo/irrigação sanguínea , Osteomielite/diagnóstico , Valor Preditivo dos Testes , Lesões dos Tecidos Moles/diagnóstico , Resultado do Tratamento , Cicatrização/fisiologia
18.
Int J Low Extrem Wounds ; 16(3): 208-211, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28825333

RESUMO

Loss of soft tissue coverage distally around the foot poses threats of amputation of the exposed boney structures. An amputation of a portion of the foot leads to loss of the biomechanical structural integrity of the foot. This promulgates an imbalance with its inherent risks of developing new ulcers. This in turn potentiates the limb loss cycle. The reverse abductor hallucis muscle flap is ideally suited for small to moderate-sized defects in the vicinity of the first metatarsophalangeal joint based on its arc of rotation. In this article, we present cases of 5 patients who failed local wound care and healing by secondary intention for at least 6 months duration. The patients were treated successfully using reverse abductor hallucis muscle flap.


Assuntos
Pé Diabético/cirurgia , Articulação Metatarsofalângica/cirurgia , Retalho Miocutâneo/transplante , Procedimentos de Cirurgia Plástica/métodos , Cicatrização/fisiologia , Adulto , Pé Diabético/fisiopatologia , Feminino , Seguimentos , Rejeição de Enxerto , Sobrevivência de Enxerto , Humanos , Masculino , Articulação Metatarsofalângica/patologia , Pessoa de Meia-Idade , Retalho Miocutâneo/irrigação sanguínea , Estudos Retrospectivos , Estudos de Amostragem , Resultado do Tratamento
19.
J Biol Chem ; 287(30): 24955-66, 2012 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-22679017

RESUMO

Ran (Ras-related nuclear) protein, a member of the Ras superfamily of GTPases, is best known for its roles in nucleocytoplasmic transport, mitotic spindle fiber assembly, and nuclear envelope formation. Recently, we have shown that the overexpression of Ran in fibroblasts induces cellular transformation and tumor formation in mice (Ly, T. K., Wang, J., Pereira, R., Rojas, K. S., Peng, X., Feng, Q., Cerione, R. A., and Wilson, K. F. (2010) J. Biol. Chem. 285, 5815-5826). Here, we describe a novel activated Ran mutant, Ran(K152A), which is capable of an increased rate of GDP-GTP exchange and an accelerated GTP binding/GTP hydrolytic cycle compared with wild-type Ran. We show that its expression in NIH-3T3 fibroblasts induces anchorage-independent growth and stimulates cell invasion, as well as activates signaling pathways that lead to extracellular regulated kinase (ERK) activity. Furthermore, Ran(K152A) expression in the human mammary SKBR3 adenocarcinoma cell line gives rise to an enhanced transformed phenotype and causes a robust stimulation of both ERK and the N-terminal c-Jun kinase (JNK). Microarray analysis reveals that the expression of the gene encoding SMOC-2 (secreted modular calcium-binding protein-2), which has been shown to synergize with different growth factors, is increased by at least 50-fold in cells stably expressing Ran(K152A) compared with cells expressing control vector. Knocking down SMOC-2 expression greatly reduces the ability of Ran(K152A) to stimulate anchorage-independent growth in NIH-3T3 cells and in SKBR3 cells and also inhibits cell invasion in fibroblasts. Collectively, our findings highlight a novel connection between the hyper-activation of the small GTPase Ran and the matricellular protein SMOC-2 that has important consequences for oncogenic transformation.


Assuntos
Transformação Celular Neoplásica/metabolismo , Mutação de Sentido Incorreto , Proteína ran de Ligação ao GTP/metabolismo , Substituição de Aminoácidos , Animais , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Linhagem Celular Tumoral , Transformação Celular Neoplásica/genética , Ativação Enzimática/genética , Humanos , Camundongos , Células NIH 3T3 , Proteína ran de Ligação ao GTP/genética
20.
J Biol Chem ; 285(8): 5815-26, 2010 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-20028979

RESUMO

Although the small GTPase Ran is best known for its roles in nucleocytoplasmic transport, mitotic spindle assembly, and nuclear envelope formation, recent studies have demonstrated the overexpression of Ran in multiple tumor types and that its expression is correlated with a poor patient prognosis, providing evidence for the importance of this GTPase in cell growth regulation. Here we show that Ran is subject to growth factor regulation by demonstrating that it is activated in a serum-dependent manner in human breast cancer cells and, in particular, in response to heregulin, a growth factor that activates the Neu/ErbB2 tyrosine kinase. The heregulin-dependent activation of Ran requires mTOR (mammalian target of rapamycin) and stimulates the capped RNA binding capability of the cap-binding complex in the nucleus, thus influencing gene expression at the level of mRNA processing. We further demonstrate that the excessive activation of Ran has important consequences for cell growth by showing that a novel, activated Ran mutant is sufficient to transform NIH-3T3 cells in an mTOR- and epidermal growth factor receptor-dependent manner and that Ran-transformed cells form tumors in mice.


Assuntos
Neoplasias da Mama/enzimologia , Núcleo Celular/enzimologia , Transformação Celular Neoplásica/metabolismo , Neuregulina-1/metabolismo , Proteína ran de Ligação ao GTP/metabolismo , Animais , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Núcleo Celular/genética , Transformação Celular Neoplásica/genética , Ativação Enzimática/efeitos dos fármacos , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Camundongos , Mutação , Células NIH 3T3 , Neuregulina-1/farmacologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Ligação ao Cap de RNA/genética , Proteínas de Ligação ao Cap de RNA/metabolismo , Processamento Pós-Transcricional do RNA/efeitos dos fármacos , Processamento Pós-Transcricional do RNA/genética , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Serina-Treonina Quinases TOR , Proteína ran de Ligação ao GTP/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...