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3.
Oncogene ; 36(46): 6374-6382, 2017 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-28745314

RESUMO

Myoferlin, a member of ferlin family of proteins, was first discovered as a candidate gene for muscular dystrophy and cardiomyopathy. Recently, myoferlin was shown to be also expressed in endothelial and cancer cells where it was shown to modulate vascular endothelial growth factor (VEGFR)-2 and epidermal growth factor receptor (EGFR) signaling by enhancing their stability and recycling. Based on these reports, we hypothesized that myoferlin might be regulating IL-6 signaling by modulating IL-6R stabilization and recycling. However, in our immunoprecipitation (IP) experiments, we did not observe myoferlin binding with IL-6R. Instead, we made a novel discovery that in resting cells myoferlin was bound to EHD2 protein and when cells were treated with IL-6, myoferlin dissociated from EHD2 and binds to activated STAT3. Interestingly, myoferlin depletion did not affect STAT3 phosphorylation, but completely blocked STAT3 translocation to nucleus. In addition, inhibition of STAT3 phosphorylation by phosphorylation-defective STAT3 mutants or JAK inhibitor blocked STAT3 binding to myoferlin and nuclear translocation. Myoferlin knockdown significantly decreased IL-6-mediated tumor cell migration, tumorsphere formation and ALDH-positive cancer stem cell population, in vitro. Furthermore, myoferlin knockdown significantly decreased IL-6-meditated tumor growth and tumor metastasis. Based on these results, we have proposed a novel model for the role of myoferlin in chaperoning phosphorylated STAT3 to the nucleus.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Núcleo Celular/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Musculares/metabolismo , Fator de Transcrição STAT3/metabolismo , Animais , Western Blotting , Proteínas de Ligação ao Cálcio/genética , Proteínas de Transporte/metabolismo , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Interleucina-6/farmacologia , Proteínas de Membrana/genética , Camundongos SCID , Microscopia de Fluorescência , Proteínas Musculares/genética , Ligação Proteica/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Interferência de RNA , Fator de Transcrição STAT3/genética , Transdução de Sinais/efeitos dos fármacos , Transplante Heterólogo
4.
AJNR Am J Neuroradiol ; 27(1): 101-6, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16418366

RESUMO

BACKGROUND AND PURPOSE: Current organ-preservation regimens for upper aerodigestive tract squamous cell carcinoma (SCCA) require endoscopic procedures under general anesthesia to evaluate the tumor response. The purpose of our study was to determine whether CT perfusion (CTP) parameters correlate with response to induction chemotherapy as assessed by endoscopy under general anesthesia. METHODS: Nine patients with advanced (stage 3 or 4) SCCA of the oropharynx were enrolled in a nested phase 2 prospective trial in which induction chemotherapy was used to assess the tumor response. Patients underwent direct laryngoscopy and CTP before and 3 weeks after one cycle of induction chemotherapy. The outcome variables were the surgeon's estimate of tumor volume during endoscopy with biopsy under anesthesia and CTP parameters (capillary permeability (CP), blood volume (BV), blood flow (BF), and mean transit time (MTT)). Wilcoxon rank sum analysis was used to correlate the baseline values of BF and BV with response to induction chemotherapy. Comparison of agreement between the reduction in tumor volume and change in CTP parameters was performed by using kappa estimates. RESULTS: Seven of 9 patients demonstrated > or =50% tumor volume reduction, representing positive response to induction chemotherapy. In the responder group, the following changes in mean pre- and postinduction chemotherapy values were noted: mean BF, 114.2 mL/100 g /min (preinduction) to 45.1 mL/100 g/min (postinduction); mean BV, 5.11 mL/100 g to 3.1 mL/100 g; mean CP, 25.6 mL/100 g /min (preinduction) to 18.3 mL/100 g / min (postinduction); mean MTT, 4.9 seconds (preinduction) to 8.0 seconds (postinduction). In the nonresponder group, the following changes were noted: mean BF, 56.9 mL/100 g/min to 75.9 mL/100 g/min; mean, BV 2.7 mL/100 g to 4.71 mL/100 g; mean CP, 24.1 mL/100 g/min to 23.7 mL/100 g/min; mean MTT, 4.3 seconds to 5.34 seconds. Higher baseline (pretherapy) values of BV showed significant correlation with endoscopic tumor response (P < .05). Reduction in the BV (by >/=20%) on follow-up studies also showed substantial agreement with clinical response as assessed with endoscopy (kappa = 0.73). The agreement between decreased BF, decreased CP, and increased MTT and clinical response was fair (kappa = 0.37). CONCLUSION: These preliminary results show that deconvolution-based CTP technique offers potential for noninvasive monitoring of response to induction chemotherapy in patients with oropharyngeal cancers. Percentage reduction of BV is significantly correlated to endoscopic response to induction chemotherapy, though we acknowledge that the data correspond to short-term outcomes and long-term durability of response cannot be established. Nevertheless, validation of the use of deconvolution CTP parameters as predictors of tumor response may permit replacement of an invasive diagnostic procedure conducted under anesthesia currently used to assess response with noninvasive perfusion CT imaging.


Assuntos
Carcinoma de Células Escamosas/diagnóstico por imagem , Endoscopia , Neoplasias Orofaríngeas/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Idoso , Carcinoma de Células Escamosas/irrigação sanguínea , Carcinoma de Células Escamosas/tratamento farmacológico , Meios de Contraste , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante , Neoplasias Orofaríngeas/irrigação sanguínea , Neoplasias Orofaríngeas/tratamento farmacológico
5.
J Clin Oncol ; 19(3): 792-9, 2001 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-11157033

RESUMO

PURPOSE: To examine the feasibility and dose-limiting toxicity (DLT) of once-weekly gemcitabine at doses predicted in preclinical studies to produce radiosensitization, concurrent with a standard course of radiation for locally advanced head and neck cancer. Tumor incorporation of gemcitabine triphosphate (dFdCTP) was measured to assess whether adequate concentrations were achieved at each dose level. PATIENTS AND METHODS: Twenty-nine patients with unresectable head and neck cancer received a course of radiation (70 Gy over 7 weeks, 5 days weekly) concurrent with weekly infusions of low-dose gemcitabine. Tumor biopsies were performed after the first gemcitabine infusion (before radiation started), and the intracellular concentrations of dFdCTP were measured. RESULTS: Severe acute and late mucosal and pharyngeal-related DLT required de-escalation of gemcitabine dose in successive patient cohorts receiving dose levels of 300 mg/m(2)/wk, 150 mg/m(2)/wk, and 50 mg/m(2)/wk. No DLT was observed at 10 mg/m(2)/wk. The rate of endoscopy- and biopsy-assessed complete tumor response was 66% to 87% in the various cohorts. Tumor dFdCTP levels were similar in patients receiving 50 to 300 mg/m(2) (on average, 1.55 pmol/mg, SD 1.15) but were barely or not detectable at 10 mg/m(2). CONCLUSION: A high rate of acute and late mucosa-related DLT and a high rate of complete tumor response were observed in this regimen at the dose levels of 50 to 300 mg/m(2), which also resulted in similar, subcytotoxic intracellular dFdCTP concentrations. These results demonstrate significant tumor and normal tissue radiosensitization by low-dose gemcitabine. Different regimens of combined radiation and gemcitabine should be evaluated, based on newer preclinical data promising an improved therapeutic ratio.


Assuntos
Antimetabólitos Antineoplásicos/efeitos adversos , Desoxicitidina/efeitos adversos , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/radioterapia , Radiossensibilizantes/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Antimetabólitos Antineoplásicos/farmacocinética , Antimetabólitos Antineoplásicos/uso terapêutico , Biópsia , Terapia Combinada , Nucleotídeos de Citosina/metabolismo , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacocinética , Desoxicitidina/uso terapêutico , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Radiossensibilizantes/farmacocinética , Radiossensibilizantes/uso terapêutico , Radioterapia/efeitos adversos , Gencitabina
6.
Int J Radiat Oncol Biol Phys ; 50(2): 377-85, 2001 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-11380224

RESUMO

PURPOSE: To review the outcome of head-and-neck cancer patients re-irradiated using conformal radiation. PATIENTS AND METHODS: From 1983 to 1999, 60 patients with recurrent or new primary head-and-neck cancer received re-irradiation at the University of Michigan. Twenty patients were excluded due to the planned cumulative radiation dose being less than 100 Gy (18) and absence of prior radiation details (2), leaving 40 patients. Thirty-five patients were re-irradiated for unresectable disease, while 4 patients received adjuvant re-irradiation for high-risk disease. Thirty-eight patients had recurrences from previously treated cancer (19 regional, 14 local, 5 regional and local), and 2 patients had new primary tumors. The median time from the first course of radiation to re-irradiation was 21 months. Thirty-one patients (78%) were re-irradiated with curative intent, whereas 9 were treated with palliative intent. Re-irradiation was delivered using conformal techniques in the majority of patients and with concurrent chemotherapy in 14 patients. The median re-irradiation dose was 60 Gy. The median cumulative dose received was 121 Gy. Five patients (13%) did not complete their prescribed course of re-irradiation. RESULTS: The median survival following completion of re-irradiation was 12.5 months. The 1- and 2-year actuarial survival rates were 51.1% and 32.6%, respectively. On multivariate analysis, palliative intent of treatment, tumor bulk, and tumor site other than nasopharynx or larynx were associated with worse survival. The patients treated for unresectable disease did no worse than those treated adjuvantly. The median times to relapse-free survival, local-regional recurrence (LRR)-free survival, and ultimate LRR-free survival (allowing for surgical salvage) were 3.9 months, 7.8 months, and 8.7 months, respectively. Seven patients (18%) are presently alive with no evidence of disease, with a median follow-up of 49.9 months (range 3.3-78.9). Severe radiation-induced complications were seen in 7 patients (18%). Two other patients developed orocutaneous fistulas in the presence of tumor recurrence. Moderate fibrosis and trismus were common. CONCLUSION: Despite the use of conformal techniques, the prognosis of patients treated with re-irradiation is poor, and complications are not infrequent. A subset of patients is salvageable, and high-dose re-irradiation should be considered in selected patients.


Assuntos
Neoplasias de Cabeça e Pescoço/radioterapia , Recidiva Local de Neoplasia/radioterapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carboplatina/administração & dosagem , Cisplatino/administração & dosagem , Terapia Combinada , Intervalo Livre de Doença , Feminino , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/tratamento farmacológico , Radioterapia Conformacional/efeitos adversos , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento
7.
Hematol Oncol Clin North Am ; 13(4): 679-87, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10494506

RESUMO

This article summarizes the most common effects of organ-preservation protocols on head and neck tissues. These highly successful regimens create special problems, such as wound complications and mandibular ORN, that the surgeon must consider. The evolution of reconstructive techniques for the head and neck, culminating with micro-vascular free-tissue transfer, has provided solutions to many of the problems created by these innovative treatments. Continued refinement of these techniques will offer patients the benefits of organ-sparing protocols while assuring an excellent functional outcome should salvage surgery become necessary.


Assuntos
Neoplasias de Cabeça e Pescoço/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Osso e Ossos/efeitos da radiação , Tecido Conjuntivo/efeitos da radiação , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/radioterapia , Humanos
8.
Hematol Oncol Clin North Am ; 15(2): 261-76, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11370492

RESUMO

Conservation surgery for cancers of the larynx and pyriform sinus is an expansive and complicated subject. A great deal of technical expertise and clinical judgement are required for appropriate surgical and oncologic outcomes. In the appropriate setting, surgery continues to play an important role in voice preservation for patients with laryngeal and hypopharyngeal carcinoma. Perhaps most importantly, options for organ preservation surgery have expanded, and the number of patients requiring total laryngectomy as primary surgical management has decreased. The medical surgical decision making is complex and requires precise delineation of tumor extent, careful patient evaluation, and thorough interdisciplinary discussion to select an optimal course of treatment for the individual patient.


Assuntos
Neoplasias Laríngeas/cirurgia , Laringe/cirurgia , Humanos , Laringe/patologia
9.
Laryngoscope ; 106(7): 903-7, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8667991

RESUMO

The challenge of mandibular reconstruction rests in the difficulty of re-creating the intricate three-dimensional relationship of the oral cavity, thereby ensuring occlusal relationships, oral competence, and facial contour. Recent advances in microvascular surgery have made reliable transfer of autologous tissue possible, hut successful reconstruction depends on accurate insetting of the bone flap. The authors reviewed their five years of experience with mandibular reconstruction and found six patients with a poor reconstructive result secondary to improper insetting of the bone flap. Anteromedially rotated and free-floating proximal mandibular segments appeared to be the most significant contributor to incorrect placement of the bone flap. Based on their findings, the authors devised a simple technique for stabilizing proximal mandibular segments.


Assuntos
Mandíbula/cirurgia , Idoso , Transplante Ósseo , Feminino , Humanos , Masculino , Métodos , Microcirurgia , Pessoa de Meia-Idade , Retalhos Cirúrgicos
10.
Laryngoscope ; 111(4 Pt 1): 696-701, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11359142

RESUMO

OBJECTIVE: To determine whether tetrathiomolybdate (TM), a powerful chelator of copper, is capable of lowering the body stores of copper and suppressing the growth of head and neck squamous cell carcinoma in an orthotopic murine model. STUDY DESIGN: In vivo, murine model. METHODS: Twelve 8-week-old male C3H/HeJ mice were assigned to either a TM treatment group (n = 7) or a control group (n = 5). Serum samples were obtained from a single mouse in each group to measure the level of ceruloplasmin as a surrogate marker of total body copper on days 0, 4, and 7. Mice in both groups received a floor-of-mouth injection of 1.5 x 105 SCC VII/SF cells. After 7 to 10 days of tumor growth the treatment group received fresh water daily, to which TM was added to achieve an oral intake of 50 mg per mouse. The control group received only fresh drinking water daily. Tumor volume measurements were obtained every other day. Microvessel density counts were assessed in the tumors by Factor VIII analysis. RESULTS: Measurable tumor growth was achieved in 100% of the mice by the tenth day. Total body copper was reduced by 28% from baseline levels in mice in the treatment group. The difference in mean tumor volume in the control group was 4.7 times greater than the TM-treated group at the completion of treatment (3004 mm3 and 633mm3, respectively). This accounted for an overall suppression rate of 79% (P =.008; two-tailed Student t test). In addition, microvessel density was reduced by 50% in the TM-treated group. CONCLUSION: In this initial study, the first of its kind in head and neck squamous cell carcinoma, we have demonstrated the ability of TM to significantly suppress both the growth of squamous cell carcinoma and tumor vascularity in this orthotopic murine model, suggesting its potential for efficacy in the treatment of this disease in humans.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Carcinoma de Células Escamosas/prevenção & controle , Quelantes/uso terapêutico , Cobre , Neoplasias de Cabeça e Pescoço/prevenção & controle , Molibdênio/uso terapêutico , Animais , Distinções e Prêmios , Carcinoma de Células Escamosas/irrigação sanguínea , Ceruloplasmina/análise , Cobre/metabolismo , Neoplasias de Cabeça e Pescoço/irrigação sanguínea , Masculino , Camundongos , Camundongos Endogâmicos C3H , Transplante de Neoplasias
11.
Laryngoscope ; 111(7): 1192-6, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11568540

RESUMO

PURPOSE: Previous series have demonstrated a 77% rate of major wound complications in salvage surgery of the larynx following organ preservation protocols. The purpose of this study is to determine the incidence of wound complications in these patients when microvascular free tissue transfers are used for reconstruction of the hypopharynx. DESIGN: Retrospective case series. SETTING: Academic tertiary care center. PATIENTS AND METHOD: We reviewed the medical records of 42 patients with stage III and IV laryngeal squamous cell carcinoma treated with an organ-sparing protocol consisting of induction chemotherapy followed by definitive radiation therapy. Ten of these patients who required surgical salvage were reconstructed using radial forearm free tissue or lateral arm transfer and constitute the study group. MAIN OUTCOME MEASURES: Wound complications. RESULTS: Wound complications occurred in 2 patients (20%) undergoing free flap reconstruction of the hypopharynx after organ preservation protocols, which was significantly lower (P =.003) than previous reports using other forms of closure and/or reconstruction. One patient in this study group had a small pharyngocutaneous fistula that resolved with conservative therapy after 1 week. The other patient had a larger pharyngocutaneous fistula that resolved over 3 weeks. The mean interval from completion of the chemoradiation regimen to surgery was 21.3 months (range, 2-60 mo). The average free tissue flap size was 94.3 cm(2) (range, 45-165 cm(2)). Average harvest and ischemia times were 59 minutes (range, 41-87 min) and 187.7 minutes (range, 120-240 min), respectively. All flaps survived, and one patient had a minor donor site wound dehiscence. The average hospital stay was 7.8 days. There were no mortalities in this series. CONCLUSIONS: Our results suggest that free tissue transfer reconstruction of the hypopharynx is the preferred method of reconstruction following combined chemotherapy and radiation therapy protocols. Surgical complications are significantly reduced and hospital stays are minimized.


Assuntos
Carcinoma de Células Escamosas/cirurgia , Hipofaringe/cirurgia , Neoplasias Laríngeas/cirurgia , Procedimentos de Cirurgia Plástica , Retalhos Cirúrgicos , Cicatrização , Adulto , Idoso , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Estudos de Coortes , Terapia Combinada , Interpretação Estatística de Dados , Feminino , Seguimentos , Humanos , Neoplasias Laríngeas/tratamento farmacológico , Neoplasias Laríngeas/radioterapia , Laringectomia , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento
12.
Arch Otolaryngol Head Neck Surg ; 127(8): 970-4, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11493208

RESUMO

OBJECTIVE: To evaluate the feasibility and predictive ability of the sentinel node localization technique for patients with squamous cell carcinoma of the oral cavity or oropharynx and clinically negative necks. DESIGN: Prospective, efficacy study comparing the histopathologic status of the sentinel node with that of the remaining neck dissection specimen. SETTING: Tertiary referral center. PATIENTS: Patients with T1 or T2 disease and clinically negative necks were eligible for the study. Nine previously untreated patients with oral cavity or oropharyngeal squamous cell carcinoma were enrolled in the study. INTERVENTIONS: Unfiltered technetium Tc 99m sulfur colloid injections of the primary tumor and lymphoscintigraphy were performed on the day before surgery. Intraoperatively, the sentinel node(s) was localized with a gamma probe and removed after tumor resection and before neck dissection. MAIN OUTCOME MEASURES: The primary outcome was the negative predictive value of the histopathologic status of the sentinel node for predicting cervical metastases. RESULTS: Sentinel nodes were identified in 9 previously untreated patients. In 5 patients, there were no positive nodes. In 4 patients, the sentinel nodes were the only histopathologically positive nodes. In previously untreated patients, the sentinel node technique had a negative predictive value of 100% for cervical metastasis. CONCLUSIONS: Our preliminary investigation shows that sentinel node localization is technically feasible in head and neck surgery and is predictive of cervical metastasis. The sentinel node technique has the potential to decrease the number of neck dissections performed in clinically negative necks, thus reducing the associated morbidity for patients in this group.


Assuntos
Carcinoma de Células Escamosas/secundário , Linfonodos/diagnóstico por imagem , Neoplasias Bucais/patologia , Neoplasias Orofaríngeas/patologia , Biópsia de Linfonodo Sentinela , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/cirurgia , Estudos de Viabilidade , Feminino , Humanos , Excisão de Linfonodo , Linfonodos/patologia , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/cirurgia , Pescoço , Neoplasias Orofaríngeas/cirurgia , Valor Preditivo dos Testes , Estudos Prospectivos , Cintilografia , Compostos Radiofarmacêuticos , Coloide de Enxofre Marcado com Tecnécio Tc 99m
13.
Otolaryngol Head Neck Surg ; 116(1): 68-74, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9018261

RESUMO

Kartagener's syndrome is characterized by the clinical triad of bronchitis, sinusitis, and situs inversus. An inherited ultrastructural defect results in ciliary immotility with impaired mucociliary clearance throughout the pulmonary and sinonasal passages. Until recently, the diagnosis of Kartagener's syndrome was made on the basis of a qualitative decrease in the number of dynein arms and subjective abnormalities in other ciliary components on electron microscopy. New investigations, however, have defined objective methods of diagnosis on the basis of quantitative ciliary measurements. The use of these methods in a series of 17 cases of suspected ciliary immotility resulted in a reversal of diagnosis in 6 cases (35%) that previously were considered normal. These results suggest that the prevalence of inherited ciliary dyskinesias is much greater than currently is recognized. The early identification and treatment of individuals with these disorders could lead to a reduction in irreversible sinus and pulmonary pathologic conditions with improved long-term survival.


Assuntos
Síndrome de Kartagener/diagnóstico , Mucosa Nasal/patologia , Seios Paranasais/patologia , Biópsia , Criança , Cílios/ultraestrutura , Humanos , Síndrome de Kartagener/patologia , Masculino , Microscopia Eletrônica
14.
Otolaryngol Head Neck Surg ; 120(1): 5-11, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9914542

RESUMO

The management of traumatic optic neuropathy remains controversial. In this report, we present the results of 45 patients treated with extracranial optic nerve decompression after at least 12 to 24 hours of corticosteroid therapy without improvement. Vision improved in 32 patients after surgery (71%), and the mean percentage of improvement from preoperative visual deficit was 40.7% +/- 6.9% (median improvement 41.2%). Worsening of vision occurred in none of the patients as a result of the surgery, and no intraoperative or postoperative complications were encountered. We present a treatment protocol for traumatic optic neuropathy with the use of megadose corticosteroids and optic nerve decompression.


Assuntos
Descompressão Cirúrgica , Doenças do Nervo Óptico/cirurgia , Adolescente , Adulto , Idoso , Dexametasona/uso terapêutico , Feminino , Glucocorticoides/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Doenças do Nervo Óptico/tratamento farmacológico , Doenças do Nervo Óptico/etiologia , Falha de Tratamento , Resultado do Tratamento
15.
Oncogene ; 33(16): 2040-52, 2014 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-23708658

RESUMO

Emerging evidence indicates that Nanog is intimately involved in tumorigenesis, in part, through regulation of the cancer-initiating cell (CIC) population. However, the regulation and role of Nanog in tumorigenesis are still poorly understood. In this study, human Nanog was identified to be phosphorylated by human protein kinase Cɛ at multiple residues, including T200 and T280. Our work indicated that phosphorylation at T200 and T280 modulates Nanog function through several regulatory mechanisms. Results with phosphorylation-insensitive and phosphorylation-mimetic mutant Nanog revealed that phosphorylation at T200 and T280 enhance Nanog protein stability. Moreover, phosphorylation-insensitive T200A and T280A mutant Nanog had a dominant-negative function to inhibit endogenous Nanog transcriptional activity. Inactivation of Nanog was due to impaired homodimerization, DNA binding, promoter occupancy and p300, a transcriptional co-activator, recruitment resulting in a defect in target gene-promoter activation. Ectopic expression of phosphorylation-insensitive T200A or T280A mutant Nanog reduced cell proliferation, colony formation, invasion, migration and the CIC population in head and neck squamous cell carcinoma (HNSCC) cells. The in vivo cancer-initiating ability was severely compromised in HNSCC cells expressing phosphorylation-insensitive T200A or T280A mutant Nanog; 87.5% (14/16), 12.5% (1/8), and 0% (0/8) for control, T200A, and T280A, respectively. Nanog occupied the Bmi1 promoter to directly transactivate and regulate Bmi1. Genetic ablation and rescue experiments demonstrated that Bmi1 is a critical downstream signaling node for the pleiotropic, pro-oncogenic effects of Nanog. Taken together, our study revealed, for the first time, that post-translational phosphorylation of Nanog is essential to regulate Bmi1 and promote tumorigenesis.


Assuntos
Transformação Celular Neoplásica/genética , Regulação Neoplásica da Expressão Gênica , Proteínas de Homeodomínio/genética , Complexo Repressor Polycomb 1/genética , Animais , Sequência de Bases , Sítios de Ligação/genética , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Células HEK293 , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/patologia , Proteínas de Homeodomínio/metabolismo , Humanos , Immunoblotting , Espectrometria de Massas , Camundongos , Camundongos Nus , Mutação , Proteína Homeobox Nanog , Fosforilação , Complexo Repressor Polycomb 1/metabolismo , Regiões Promotoras Genéticas/genética , Proteína Quinase C-épsilon/genética , Proteína Quinase C-épsilon/metabolismo , Treonina/genética , Treonina/metabolismo , Transplante Heterólogo
16.
Oncogene ; 33(8): 1037-46, 2014 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-23474763

RESUMO

The incidence of human papillomavirus (HPV)-positive head and neck squamous cell carcinoma (HNSCC) has rapidly increased over the past 30 years, prompting the suggestion that an epidemic maybe on the horizon. Therefore, there is a clinical need to develop alternate therapeutic strategies to manage the growing number of HPV-positive HNSCC patients. High-risk HPV E6 inactivates p53 through two distinct mechanisms; association with E6AP to degrade p53 and association with p300 to block p300-mediated p53 acetylation and activation. In this study, we determined if targeting the E6-p300 interaction is an effective approach to reactivate p53 in HPV-positive HNSCC. Ectopic expression of the CH1 domain of p300 in HPV-positive HNSCC blocks the association between E6 and p300, increases total and acetylated p53 levels and enhances p53 transcriptional activity. Moreover, expression of p21, miR-34a and miR-200c are increased, demonstrating functional p53 reactivation. CH1 overexpression in HPV-positive HNSCC has a global anticancer effect resulting in a decrease in cell proliferation and clonogenic survival and an increase in apoptosis. The in vivo tumor-initiating ability of HPV-positive HNSCC is severely compromised with CH1 overexpression, in part through a reduction in the cancer-initiating cell population. A novel small-molecule CH1 inhibitor, CH1iB, reactivates p53 and potentiates the anticancer activity of cis-platinum in HPV-positive HNSCC cells. Our work shows that CH1-domain inhibitors represent a novel class of p53-reactivation therapeutics for managing HPV-positive HNSCC patients.


Assuntos
Alphapapillomavirus/isolamento & purificação , Carcinoma de Células Escamosas/metabolismo , Neoplasias de Cabeça e Pescoço/metabolismo , Proteínas Oncogênicas Virais/metabolismo , Proteínas Repressoras/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Fatores de Transcrição de p300-CBP/metabolismo , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/virologia , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/virologia , Humanos
17.
Oncogene ; 31(36): 4045-53, 2012 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-22158047

RESUMO

Head and neck squamous cell carcinoma (HNSCC) is the sixth most prevalent cancer worldwide with about 600 000 new cases diagnosed each year. Understanding the molecular pathways that lead to HNSCC is crucial to identify new targets for anti-cancer drug development. Protein kinase Cɛ (PKCɛ) is elevated in HNSCC and regulates the activation of Akt, Stat3 and Rho GTPases. To date, the molecular mechanism of PKCɛ dysregulation in HNSCC remains to be elucidated. In silico analysis identified three putative microRNA-107 (miR-107) binding sites in the 3'-untranslated region (UTR) of PKCɛ. An inverse relationship was revealed between miR-107 and PKCɛ in HNSCC cell lines. Delivery of miR-107 reduced PKCɛ levels in SCC15, SCC25 and CAL27, three HNSCC cell lines with high PKCɛ and low miR-107. The activity of a luciferase reporter construct containing the 3'-UTR of PKCɛ was downregulated by miR-107 and mutations in the three cognate miR-107 binding sites completely ablated the regulation by miR-107. Treatment with miR-107 significantly blocked cell proliferation, DNA replication, colony formation and invasion in SCC25 and CAL27 cells. Ectopic expression of miR-resistant PKCɛ was sufficient to partially rescue the loss-of-function phenotype in miR-107-overexpressing SCC25 cells. Tumor growth in nude mice was retarded by 93±7% in CAL27/miR-107 cells compared with CAL27/miR-control cells. Last, human primary HNSCC tumors with elevated PKCɛ had reduced miR-107 expression. Our results demonstrate that PKCɛ is directly regulated by miR-107 and, moreover, suggest that miR-107 may be a potential anti-cancer therapeutic for HNSCC.


Assuntos
Carcinoma de Células Escamosas/genética , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor , Neoplasias de Cabeça e Pescoço/genética , MicroRNAs/fisiologia , Proteína Quinase C-épsilon/genética , Animais , Sequência de Bases , Carcinoma de Células Escamosas/enzimologia , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Transformação Celular Neoplásica , Regulação para Baixo , Neoplasias de Cabeça e Pescoço/enzimologia , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Camundongos , Camundongos Nus , MicroRNAs/genética , MicroRNAs/metabolismo , Invasividade Neoplásica , Transplante de Neoplasias , Proteína Quinase C-épsilon/metabolismo , Carga Tumoral
19.
Am J Rhinol ; 14(6): 387-91, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11197115

RESUMO

Nasal and paranasal sinus manifestations are among the most common presentations of the acquired immunodeficiency syndrome (AIDS). Several studies cite that as many as 70% of patients with this disease have symptoms referable to the head and neck, including a 30% prevalence of sinusitis. Although the bacteriology of sinusitis in this population is largely considered comparable to that of immunocompetent patients, several opportunistic pathogens have been identified, particularly when T-cell counts are low. This report identifies Acanthamoeba as a potentially fatal cause of rhinosinusitis in immunosuppressed patients. The pathogenesis, diagnosis, and treatment of this rare entity will be discussed and the literature reviewed.


Assuntos
Síndrome da Imunodeficiência Adquirida/complicações , Amebíase/diagnóstico , Amebíase/cirurgia , Rinite/complicações , Rinite/parasitologia , Sinusite/complicações , Sinusite/parasitologia , Acanthamoeba , Adulto , Amebíase/patologia , Animais , Antibacterianos/uso terapêutico , Antiprotozoários/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Pós-Operatórios
20.
J Craniofac Surg ; 8(5): 352-5; discussion 356-9, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9482075

RESUMO

Blindness can result from traumatic optic neuropathy following facial trauma and can complicate the management of concomitant facial fractures. Traumatic optic neuropathy can cause a substantial delay in the repair of facial fractures, leading to compromised surgical results. It can also result in postoperative visual loss following facial fracture repair. We present four cases of traumatic optic neuropathy that compromised the treatment of facial fractures. The management of facial fractures in patients with traumatic optic neuropathy must proceed cautiously. Delayed primary repair of midface fractures by postponing surgery for 10 to 14 days may be of benefit in avoiding further deterioration of vision. In addition, megadose corticosteroids and/or optic nerve decompression is useful in the management of these patients.


Assuntos
Ossos Faciais/lesões , Síndromes de Compressão Nervosa/etiologia , Traumatismos do Nervo Óptico , Fraturas Cranianas/complicações , Corticosteroides/uso terapêutico , Adulto , Cegueira/etiologia , Emergências , Ossos Faciais/diagnóstico por imagem , Ossos Faciais/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Síndromes de Compressão Nervosa/diagnóstico por imagem , Síndromes de Compressão Nervosa/cirurgia , Nervo Óptico/cirurgia , Fraturas Cranianas/diagnóstico por imagem , Fraturas Cranianas/cirurgia , Tomografia Computadorizada por Raios X
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