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1.
Methodist Debakey Cardiovasc J ; 20(3): 13-18, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38765214

RESUMO

With a multitude of options for pulmonary embolism management, we review the most common diagnostic tools available for assessing risk as well as how each broad risk category is typically treated. Right heart dysfunction is the cornerstone for triage of these patients and should be the focus for decision-making, especially in challenging patients. We aim to provide a modern, clinical perspective for PE management in light of the multitude of intervention options.


Assuntos
Tomada de Decisão Clínica , Embolia Pulmonar , Embolia Pulmonar/terapia , Embolia Pulmonar/diagnóstico , Embolia Pulmonar/fisiopatologia , Embolia Pulmonar/diagnóstico por imagem , Humanos , Fatores de Risco , Resultado do Tratamento , Medição de Risco , Valor Preditivo dos Testes , Terapia Trombolítica/efeitos adversos , Embolectomia , Procedimentos Endovasculares/efeitos adversos , Anticoagulantes/uso terapêutico , Anticoagulantes/efeitos adversos , Seleção de Pacientes , Trombectomia
2.
Artigo em Inglês | MEDLINE | ID: mdl-38765216

RESUMO

Introductory overview for Methodist DeBakey Cardiovascular Journal Issue 20.3 on Pulmonary Embolism, written by the issues' guest editors.


Assuntos
Embolia Pulmonar , Embolia Pulmonar/terapia , Embolia Pulmonar/diagnóstico , Humanos , Fatores de Risco , Resultado do Tratamento
3.
Eur Arch Otorhinolaryngol ; 281(5): 2645-2653, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38498191

RESUMO

PURPOSE: Locally-advanced oropharynx (LA-OPSCC) and hypopharynx/larynx (LA-HPLSCC) cancers may be treated with surgical or non-surgical modalities. While survival outcomes are comparable, patterns of disease recurrence are not well established. METHODS: Retrospective review of 98 consecutive patients with LA-OPSCC or LA-HPLSCC treated by either surgery plus adjuvant therapy (S-POAT, n = 48) or chemoradiation (CRT, n = 50). RESULTS: CRT-treated patients had higher recurrence risk (42% vs 14.6%, p = 0.003). This was significant only among LA-OPSCC (p = 0.002) but not LA-HPLSCC patients (p = 0.159). Median time to recurrence in LA-OPSCC was 16.8 vs 11.6 months, and 16.6 vs 15.1 months in LA-HPLSCC, comparing surgically treated and CRT cohorts. Surgically-treated p16-negative LA-OPSCC experienced improved locoregional control than CRT-treated patients (100% vs 12.5%, p = 0.045) and 3-year RFS (83.0% vs 33.3%, p < 0.001). CONCLUSION: Locoregional control and RFS benefit was observed in surgically treated p16 negative LA-OPSCC patients. Locoregional recurrence is the main reason of treatment failure in LA-HNSCC, occurring commonly within the first 2 years post-treatment, regardless of treatment option.


Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Neoplasias Orofaríngeas , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço/terapia , Recidiva Local de Neoplasia/terapia , Quimiorradioterapia , Neoplasias de Cabeça e Pescoço/terapia , Estudos Retrospectivos , Neoplasias Orofaríngeas/cirurgia
4.
Cancer Cytopathol ; 132(5): 309-319, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38319805

RESUMO

BACKGROUND: Most thyroid nodules are benign. It is important to determine the likelihood of malignancy in such nodules to avoid unnecessary surgery. The primary objective of this study was to characterize the genetic landscape and the performance of a multigene genomic classifier in fine-needle aspiration (FNA) biopsies of cytologically indeterminate thyroid nodules in a Southeast Asian cohort. The secondary objective was to assess the predictive contribution of clinical characteristics to thyroid malignancy. METHODS: This prospective, multicenter, blinded study included 132 patients with 134 nodules. Molecular testing (MT) with ThyroSeq v3 was performed on clinical or ex-vivo FNA samples. Centralized pathology review also was performed. RESULTS: Of 134 nodules, consisting of 61% Bethesda category III, 20% category IV, and 19% category V cytology, and 56% were histologically malignant. ThyroSeq yielded negative results in 37.3% of all FNA samples and in 42% of Bethesda category III-IV cytology nodules. Most positive samples had RAS-like (41.7%), followed by BRAF-like (22.6%), and high-risk (17.9%) alterations. Compared with North American patients, the authors observed a higher proportion of RAS-like mutations, specifically NRAS, in Bethesda categories III and IV and more BRAF-like mutations in Bethesda category III. The test had sensitivity, specificity, negative predictive value, and positive predictive value of 89.6%, 73.7%, 84.0%, and 82.1%, respectively. The risk of malignancy was predicted by positive MT and high-suspicion ultrasound characteristics according to American Thyroid Association criteria. CONCLUSIONS: Even in the current Southeast Asian cohort with nodules that had a high pretest cancer probability, MT could lead to potential avoidance of diagnostic surgery in 42% of patients with Bethesda category III-IV nodules. MT positivity was a stronger predictor of malignancy than clinical parameters.


Assuntos
Nódulo da Glândula Tireoide , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Sudeste Asiático , Biomarcadores Tumorais/genética , Biópsia por Agulha Fina , Genômica/métodos , Mutação , Prognóstico , Estudos Prospectivos , População do Sudeste Asiático , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/diagnóstico , Nódulo da Glândula Tireoide/genética , Nódulo da Glândula Tireoide/patologia , Nódulo da Glândula Tireoide/diagnóstico
6.
Tex Heart Inst J ; 49(2)2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35481863

RESUMO

After the introduction of the first robotic-assisted surgical procedures, the technology soon reached the world of endovascular specialists, giving rise to several publications about robotic-assisted endovascular therapy. Compared with conventional procedures, robotic-assisted procedures can be more accurate and reduce radiation exposure. The latest commercially available endovascular robotic system is the CorPath GRX, which can be operated remotely. Robotic-assisted approaches have proved applicable in the fields of coronary and peripheral vascular intervention and neurointervention. Remote intervention has already proved feasible in the coronary and peripheral vascular systems and, according to expert opinion, could revolutionize acute stroke management as well. We review current knowledge about robotic-assisted therapies and remote interventions, and the future prospects and pitfalls.


Assuntos
Doença da Artéria Coronariana , Intervenção Coronária Percutânea , Procedimentos Cirúrgicos Robóticos , Robótica , Doença da Artéria Coronariana/cirurgia , Humanos , Intervenção Coronária Percutânea/instrumentação , Intervenção Coronária Percutânea/métodos , Procedimentos Cirúrgicos Robóticos/instrumentação , Procedimentos Cirúrgicos Robóticos/métodos , Robótica/métodos , Robótica/normas , Resultado do Tratamento
7.
Front Genet ; 12: 721832, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34512731

RESUMO

BACKGROUND: The standard of care for thyroid cancer management is thyroidectomy and adjuvant radioactive iodine (RAI). There is a paucity of clinical tool that quantifies residual thyroid volume reliably for precise adjuvant RAI dosing. Serum thyroglobulin (TG), tumour marker for thyroid cancer, takes 4 weeks for complete clearance due to its long half-life, and might be undetectable in 12% of structural disease patients. It detects recurrence with a sensitivity of 19-40%, mainly attributed to issue of TG antibody interference with TG immunometric assay. We hypothesise that the quantity of thyroid-specific cell-free RNA (cfRNA) is indicative of amount of thyroid tissues, and that during thyroid surgery, cfRNA levels decrease accordingly. METHODS: We identified 11 biologically significant and highly expressed thyroid-specific targets from Human Protein Atlas and literature. To assess for a fall in thyroid-specific cfRNA level, we recruited 16 patients undergoing thyroid surgery or RAI for malignant or benign thyroid disease, and tracked longitudinal trend of cfRNA. To assess the utility of cfRNA in detecting metastatic thyroid cancer, cfRNA of 11 patients at intermediate to high risk of recurrence was measured during surveillance and at time of clinical recurrence. RESULTS: The multiplex assay was capable of amplifying and quantifying multiple thyroid-specific genes in a single reaction. The selected targets were amplified successfully from RNA extracted directly from the thyroid (positive control), indicating that they were highly expressed within thyroid tissue. These cfRNAs were present in plasma, in amounts quantifiable using qRT-PCR. Four cfRNA transcripts (TPO, GFRA2, IVD, TG) fell post-treatment in more than 50% of cohort. The thyroid peroxidase (TPO) cfRNA fell post-therapy in 63% of cohort by 80%, as early as 1 day post-treatment, supporting the potential role as early indicator of remnant thyroid tissue volume. We demonstrated the clinical relevance of circulating TPO cfRNA by tracking temporal changes in setting of peri-treatment, recurrence, and TG Ab positive state. CONCLUSION: Using a multiplex pre-amplification approach, the TPO cfRNA was a potential biomarker that can track residual thyroid mass. It can be further optimised for quantification of thyroid volume to guide RAI doses and for detection of thyroid cancer recurrence.

8.
Int J Med Robot ; 17(3): e2249, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33634563

RESUMO

BACKGROUND: Robotic-assisted endovascular surgery enables us to perform interventions from long distances. This study evaluates the workflow and telecommunication requirements of telerobotic peripheral vascular interventions. METHODS: Ten superficial femoral artery cases were performed by the operator being 44 miles away from the interventional suite, with an endovascular robotic system, on a high-fidelity endovascular simulator. Procedural success, technical success, fluoroscopy time, residual stenosis, contrast dose and network delay were registered. Communication success was assessed after each procedure on a scale from 1 (unacceptable) to 5 (ideal). RESULTS: Procedural success and technical success were 100% and 80%, respectively. The mean residual stenosis, fluoroscopy time and contrast dose were 1.7 ± 5.25%, 6.5 ± 1.8 min and 58.8 ± 14.8 ml. The mean network latency was 38.9 ± 3.5 ms. Median communication success scores were 4.5 (min: 4, max: 5) reported by both the operator and the bedside technician on a scale of 1 (unacceptable) to 5 (ideal). CONCLUSION: With a stable network connection and good communication protocol, a high success rate was achieved for remote robotic-assisted peripheral vascular intervention in an ex vivo model.


Assuntos
Procedimentos Endovasculares , Procedimentos Cirúrgicos Robóticos , Estudos de Viabilidade , Humanos , Stents , Resultado do Tratamento
9.
Eur Arch Otorhinolaryngol ; 278(7): 2461-2471, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32897441

RESUMO

PURPOSE: Consistent prognosticators are needed to guide adjuvant treatment in tongue squamous cell carcinoma (SCC). We validate the prognostic significance of histopathologic parameters in surgically treated tongue SCC. METHODS: Archival specimens of 88 consecutive patients who were treated surgically for tongue SCC from 2003 to 2016 were re-analyzed by one pathologist. Patient records were retrospectively reviewed. Prognosticators of recurrence-free survival (RFS), overall survival (OS), and disease-specific survival (DSS) were identified using multivariate analysis. RESULTS: Tumor depth of invasion (DOI) > 6 mm (OR 4.76; 95%CI 1.22-18.5; p = 0.024) and lymphovascular invasion (OR 5.61; 95%CI 1.00-31.5; p = 0.05) were independent predictors of nodal metastases. The overall 5-year RFS, OS and DSS were 70%, 82% and 84% respectively. Positive margins predicted poor RFS (HR 3.91; 95%CI 1.58-9.65; p = 0.003) and local recurrence-free survival (HR 4.96; 95%CI 1.36-18; p = 0.015). Presence of nodal metastases (HR 5.03; 95%CI 1.73-14.6; p = 0.003), tumor DOI > 6 mm (HR 9.91; 95%CI 1.26-78.0; p = 0.029) and positive margins (HR 8.26; 95%CI 2.75-24.8; p < 0.001) were independent predictors of poor OS. Presence of nodal metastases (HR 3.87; 95%CI 1.17-12.8; p = 0.027) and positive margins (HR 12.3; 95%CI 3.54-42.9; p < 0.001) also independently predicted poor DSS. CONCLUSION: Margins' status was the only independent predictor of local recurrence. Tumor DOI, nodal and margin status were key prognosticators of survival and may determine the necessity for adjuvant therapy.


Assuntos
Carcinoma de Células Escamosas , Neoplasias da Língua , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Humanos , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Língua/patologia , Neoplasias da Língua/patologia , Neoplasias da Língua/cirurgia
10.
Int J Infect Dis ; 103: 389-394, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33212260

RESUMO

BACKGROUND: Migrant worker dormitories-residential complexes where 10-24 workers share living spaces-account for the majority of cases of SARS-CoV-2 infection in Singapore. To prevent overspill of transmission to the wider population, starting in early April 2020, residents were confined to their dormitories while measures were put in place to arrest the spread of infection. This descriptive study presents epidemiological data for a population of more than 60 000 migrant workers living in two barracks-style and four apartment-style dormitories located in western Singapore from April 3 to June 10, 2020. METHODS: Our report draws from data obtained over the first 50 days of outbreak management in order to describe SARS-CoV-2 transmission in high-density housing environments. Cumulative counts of SARS-CoV-2 cases and numbers of housing units affected were analyzed to report the harmonic means of harmonic means of doubling times and their 95% confidence intervals (CI). RESULTS: Multiple transmission peaks were identified involving at least 5467 cases of SARS-CoV-2 infection across six dormitories. Our geospatial heat maps gave an early indication of outbreak severity in affected buildings. We found that the number of cases of SARS-CoV-2 infection doubled every 1.56 days (95% CI 1.29-1.96) in barracks-style buildings. The corresponding doubling time for apartment-style buildings was 2.65 days (95% CI 2.01-3.87). CONCLUSIONS: Geospatial epidemiology was useful in shaping outbreak management strategies in dormitories. Our results indicate that building design plays an integral role in transmission and should be considered in the prevention of future outbreaks.


Assuntos
COVID-19/epidemiologia , COVID-19/transmissão , Habitação , Migrantes , Adulto , COVID-19/prevenção & controle , Surtos de Doenças/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , SARS-CoV-2 , Singapura/epidemiologia , Análise Espaço-Temporal , Adulto Jovem
11.
Nucleic Acids Res ; 48(22): 12727-12745, 2020 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-33245769

RESUMO

Bcl-2 phosphorylation at serine-70 (S70pBcl2) confers resistance against drug-induced apoptosis. Nevertheless, its specific mechanism in driving drug-resistance remains unclear. We present evidence that S70pBcl2 promotes cancer cell survival by acting as a redox sensor and modulator to prevent oxidative stress-induced DNA damage and execution. Increased S70pBcl2 levels are inversely correlated with DNA damage in chronic lymphocytic leukemia (CLL) and lymphoma patient-derived primary cells as well as in reactive oxygen species (ROS)- or chemotherapeutic drug-treated cell lines. Bioinformatic analyses suggest that S70pBcl2 is associated with lower median overall survival in lymphoma patients. Empirically, sustained expression of the redox-sensitive S70pBcl2 prevents oxidative stress-induced DNA damage and cell death by suppressing mitochondrial ROS production. Using cell lines and lymphoma primary cells, we further demonstrate that S70pBcl2 reduces the interaction of Bcl-2 with the mitochondrial complex-IV subunit-5A, thereby reducing mitochondrial complex-IV activity, respiration and ROS production. Notably, targeting S70pBcl2 with the phosphatase activator, FTY720, is accompanied by an enhanced drug-induced DNA damage and cell death in CLL primary cells. Collectively, we provide a novel facet of the anti-apoptotic Bcl-2 by demonstrating that its phosphorylation at serine-70 functions as a redox sensor to prevent drug-induced oxidative stress-mediated DNA damage and execution with potential therapeutic implications.


Assuntos
Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Linfoma/tratamento farmacológico , Mitocôndrias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Apoptose/genética , Proliferação de Células/genética , Cisplatino/farmacologia , Dano ao DNA/efeitos dos fármacos , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Etoposídeo/farmacologia , Fluoruracila/farmacologia , Humanos , Células Jurkat , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/patologia , Linfoma/genética , Linfoma/patologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Oxirredução/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Cultura Primária de Células , Espécies Reativas de Oxigênio/metabolismo , Serina/genética
12.
Expert Rev Med Devices ; 17(9): 919-927, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32835546

RESUMO

INTRODUCTION: Endovascular surgery has become the standard of care to treat most vascular diseases using a minimally invasive approach. The CorPath system further enhances the potential and enables surgeons to perform robotic-assisted endovascular procedures in interventional cardiology, peripheral vascular surgery, and neurovascular surgery. With the introduction of this technique, the operator can perform multiple steps of endovascular interventions outside of the radiation field with high precision movements even from long-geographical distances. AREAS COVERED: The first and second-generation CorPath systems are currently the only commercially available robotic devices for endovascular surgery. This review article discusses the clinical experiences and outcomes with the robot, the advanced navigational features, and the results with recent hardware and software modifications, which enables the use of the system for neurovascular interventions, and long-distance interventional procedures. EXPERT OPINION: A high procedural success was achieved with the CorPath robotic systems in coronary and peripheral interventions, and the device seems promising in neurovascular procedures. More experience is needed with robotic neurovascular interventions and with complex peripheral arterial cases. In the future, long-distance endovascular surgery can potentially transform the management and treatment of acute myocardial infarction and stroke, with making endovascular care more accessible for patients in remote areas.


Assuntos
Procedimentos Endovasculares , Utilização de Procedimentos e Técnicas , Procedimentos Cirúrgicos Robóticos , Procedimentos Endovasculares/instrumentação , Humanos , Exposição Ocupacional , Proteção Radiológica , Procedimentos Cirúrgicos Robóticos/instrumentação , Resultado do Tratamento
13.
Head Neck ; 42(5): 945-954, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31909854

RESUMO

OBJECTIVES: To compare the clinical outcomes of oligometastatic versus widely metastatic NPC patients. MATERIALS AND METHODS: Retrospective review of 157 patients with metastatic NPC at a tertiary hospital was performed. Multivariate analysis was carried out to compare the overall and progression-free survival (OS and PFS) of these two cohorts of NPC patients. The number of organ involvement and discrete metastatic lesions associated with improved OS and PFS were ascertained. RESULTS: Patients with oligometastatic NPC (single organ, less than six discrete metastatic lesions) had a better median OS than patients with widespread metastasis (24.8 versus 12.8 months, P < .001). Similarly, the median PFS of oligometastatic NPC was better than that of polymetastatic NPC (11.7 versus 7.3 months, P < .001). CONCLUSION: Single organ disease with less than six discrete lesions is a good indicator of limited metastatic load in NPC, and is associated with improved survival.


Assuntos
Neoplasias Nasofaríngeas , Humanos , Carcinoma Nasofaríngeo/terapia , Neoplasias Nasofaríngeas/terapia , Prognóstico , Intervalo Livre de Progressão , Estudos Retrospectivos
14.
Redox Biol ; 30: 101403, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31954371

RESUMO

The death inhibitory proteins, cFLIP and Bcl-2, canonically act at different steps to regulate receptor-mediated apoptosis in cancer cells. Here we report that pharmacological or genetic means to effect an increase in intracellular superoxide result in cFLIP upregulation. Interestingly, Bcl-2 overexpression is associated with a concomitant increase in cFLIP, and reducing superoxide sensitizes Bcl-2 overexpressing cancer cells to receptor-mediated apoptosis via downregulation of cFLIP. Moreover, inhibiting glycolytic flux overcomes apoptosis resistance by superoxide-dependent downregulation of cFLIP. Superoxide-induced upregulation of cFLIP is a function of enhanced transcription, as evidenced by increases in cFLIP promoter activity and mRNA abundance. The positive effect of superoxide on cFLIP is mediated through its reaction with nitric oxide to generate peroxynitrite. Corroborating these findings in cell lines, subjecting primary cells derived from lymphoma patients to glucose deprivation ex vivo, as a means to decrease superoxide, not only reduced cFLIP expression but also significantly enhanced death receptor sensitivity. Based on this novel mechanistic insight into the redox regulation of cancer cell fate, modulation of intracellular superoxide could have potential therapeutic implications in cancers in which these two death inhibitory proteins present a therapeutic challenge.


Assuntos
Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/genética , Linfoma/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Superóxidos/metabolismo , Regulação para Cima , Linhagem Celular Tumoral , Sobrevivência Celular , Regulação Neoplásica da Expressão Gênica , Glicólise , Humanos , Linfoma/genética , Óxido Nítrico/metabolismo , Regiões Promotoras Genéticas , Transdução de Sinais
15.
Head Neck Pathol ; 14(2): 542-549, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31273600

RESUMO

We present a 72 years old male with a left nasal cavity (mammary analogue) secretory carcinoma (SC) which exhibited classical morphological features on light microscopical examination, diffuse strong S100 and mammoglobin positivity on immunohistochemistry, and ETV6-NTRK3 gene fusion on next generation sequencing (NGS) analysis. Unusual features of this tumor are expression of p63 and DOG1 on immunohistochemistry and the atypical junction between Exon 4 of the ETV6 gene and Exon 14 of the NTRK3 gene.


Assuntos
Biomarcadores Tumorais/análise , Carcinoma Secretor Análogo ao Mamário/genética , Cavidade Nasal/patologia , Neoplasias Nasais/genética , Proteínas de Fusão Oncogênica/genética , Idoso , Anoctamina-1/biossíntese , Éxons/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Carcinoma Secretor Análogo ao Mamário/patologia , Proteínas de Membrana/biossíntese , Proteínas de Neoplasias/biossíntese , Neoplasias Nasais/patologia , Análise de Sequência de DNA
16.
Cancer Lett ; 457: 151-167, 2019 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-31103719

RESUMO

Active GTPase-Rac1 is associated with cellular processes involved in carcinogenesis and expression of Bcl-2 endows cells with the ability to evade apoptosis. Here we provide evidence that active Rac1 and Bcl-2 work in a positive feedforward loop to promote sustained phosphorylation of Bcl-2 at serine-70 (S70pBcl-2), which stabilizes its anti-apoptotic activity. Pharmacological and genetic inactivation of Rac1 prevent interaction with Bcl-2 and reduce S70pBcl-2. Similarly, BH3-mimetic inhibitors of Bcl-2 could disrupt Rac1-Bcl-2 interaction and reduce S70pBcl-2. This effect of active Rac1 could also be rescued by scavengers of intracellular superoxide (O2.-), thus implicating NOX-activating activity of Rac1 in promoting S70pBcl-2. Moreover, active Rac1-mediated redox-dependent S70pBcl-2 involves the inhibition of phosphatase PP2A holoenzyme assembly. Sustained S70pBcl-2 in turn secures Rac1/Bcl-2 interaction. Importantly, inhibiting Rac1 activity, scavenging O2.- or employing BH3-mimetic inhibitor significantly reduced S70pBcl-2-mediated survival in cancer cells. Notably, Rac1 expression, and its interaction with Bcl-2, positively correlate with S70pBcl-2 levels in patient-derived lymphoma tissues and with advanced stage lymphoma and melanoma. Together, we provide evidence of a positive feedforward loop involving active Rac1, S70pBcl-2 and PP2A, which could have potential diagnostic, prognostic and therapeutic implications.


Assuntos
Linfoma/enzimologia , Melanoma/enzimologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Neoplasias Cutâneas/enzimologia , Proteínas rac1 de Ligação ao GTP/metabolismo , Apoptose , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos , Retroalimentação Fisiológica , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Células Jurkat , Linfoma/tratamento farmacológico , Linfoma/genética , Linfoma/patologia , Melanoma/tratamento farmacológico , Melanoma/genética , Melanoma/patologia , Mutação , NADPH Oxidases/metabolismo , Fosforilação , Ligação Proteica , Proteína Fosfatase 2/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Transdução de Sinais , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Esferoides Celulares , Superóxidos/metabolismo , Proteínas rac1 de Ligação ao GTP/genética
17.
J Vasc Surg Venous Lymphat Disord ; 7(3): 420-427, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30792152

RESUMO

OBJECTIVE: Outflow tract stenosis is the leading cause of hemodialysis access loss. Many lesions are highly resistant to endovascular treatment, necessitating open surgical intervention. We present our experience using medial claviculectomy for treatment of recalcitrant lesions at the thoracic outlet. METHODS: We retrospectively reviewed patients who underwent medial claviculectomy for dialysis-associated venous thoracic outlet syndrome at our institution between February 2013 and February 2018. Data collection included demographics, past medical history, access history, subsequent procedures, preoperative and postoperative brachial volume flows, and access use. RESULTS: We performed 25 medial claviculectomies in 25 patients with central venous stenosis. Four patients underwent concomitant central venous bypass and were excluded from this study. Twelve accesses were created at our institution; of these, the average access age was 41.6 months (±26.7 months). All patients previously underwent multiple angioplasty attempts to treat outflow stenosis and continued to have residual symptoms and poor fistula function. Medial claviculectomy with venolysis and angioplasty were performed to treat residual outflow stenosis at the level of the subclavian vein. Twenty-one patients had residual stenosis requiring angioplasty. Six patients had subclavian rupture requiring stent graft placement. All patients reported symptom improvement and immediate use of the fistula after medial claviculectomy. Nineteen (76%) patients reported complete resolution of symptoms after the procedure. Ultimately, eight (32%) ipsilateral arteriovenous accesses were lost, and six (24%) patients died in follow-up with patent, functional fistulas. Median length of follow-up was 17 months (interquartile range, 5-28 months). The 18-month primary patency and secondary patency with regard to subclavian vein interventions were 28% (95% confidence interval, 13.8%-56.1%) and 84% (95% confidence interval, 69.7%-100%), respectively. One patient required ligation for high-output cardiac failure. One patient had contralateral brachiocephalic jailing, which was corrected with kissing brachiocephalic stents. CONCLUSIONS: Medial claviculectomy is an effective treatment of recalcitrant central venous stenosis of the thoracic outlet. Balloon angioplasty or stent or stent graft placement is often necessary after extrinsic compression is alleviated and demonstrates acceptable secondary patency rates.


Assuntos
Derivação Arteriovenosa Cirúrgica/efeitos adversos , Clavícula/cirurgia , Descompressão Cirúrgica/métodos , Osteotomia , Diálise Renal , Veia Subclávia/cirurgia , Síndrome do Desfiladeiro Torácico/cirurgia , Doenças Vasculares/cirurgia , Adulto , Idoso , Angioplastia com Balão/instrumentação , Prótese Vascular , Implante de Prótese Vascular/instrumentação , Clavícula/diagnóstico por imagem , Descompressão Cirúrgica/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteotomia/efeitos adversos , Estudos Retrospectivos , Fatores de Risco , Stents , Veia Subclávia/diagnóstico por imagem , Veia Subclávia/fisiopatologia , Síndrome do Desfiladeiro Torácico/diagnóstico por imagem , Síndrome do Desfiladeiro Torácico/etiologia , Síndrome do Desfiladeiro Torácico/fisiopatologia , Fatores de Tempo , Resultado do Tratamento , Doenças Vasculares/diagnóstico por imagem , Doenças Vasculares/etiologia , Doenças Vasculares/fisiopatologia , Grau de Desobstrução Vascular
18.
Clin Otolaryngol ; 44(2): 114-123, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30294871

RESUMO

OBJECTIVE: BRAF mutation is the commonest mutation seen in papillary thyroid cancer (PTC), but its prevalence and clinical significance vary across countries. We aim to evaluate the prevalence and clinico-pathological correlation of BRAF mutation in PTC patients at our centre. STUDY DESIGN: Retrospective cohort study of 75 consecutive archival thyroid specimens, whereby BRAF mutation was detected using a polymerase chain reaction (PCR) technique and correlated with clinical and pathological features and outcomes. SETTING: Tertiary university hospital in Singapore. PARTICIPANTS: A total of 75 consecutive histologically proven archival thyroid specimens from patients who underwent thyroidectomy for PTC were accrued for this study. MAIN OUTCOME MEASURES: Main outcome is to determine the prevalence of the BRAF mutation in our South-East Asian population. Secondary aim is to correlate the mutational status with adverse pathological features like histological variants, multi-focality, lymphovascular invasion and extra-thyroidal extension, clinical features like demographics, TNM stage, recurrence and survival, as well as treatment details like type of surgery performed and radioiodine doses. RESULTS: BRAF mutation was detected in 56% (42/75) of PTC. All but one BRAF-mutated PTC had the BRAFV600E mutation. BRAF-mutated tumours were associated with an advanced T-stage (P = 0.049) and were more likely to have a central neck dissection (P = 0.036). There was no significant correlation between BRAF mutation status and clinical outcomes. CONCLUSION: The prevalence of BRAF mutation is 56%. BRAF mutation-positive tumours were associated with locally advanced disease, but not poorer survival.


Assuntos
Povo Asiático/genética , Mutação/genética , Recidiva Local de Neoplasia/epidemiologia , Proteínas Proto-Oncogênicas B-raf/genética , Câncer Papilífero da Tireoide/genética , Neoplasias da Glândula Tireoide/genética , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Singapura , Taxa de Sobrevida , Câncer Papilífero da Tireoide/mortalidade , Câncer Papilífero da Tireoide/terapia , Neoplasias da Glândula Tireoide/mortalidade , Neoplasias da Glândula Tireoide/terapia , Tireoidectomia , Adulto Jovem
19.
Artigo em Inglês | MEDLINE | ID: mdl-29666673

RESUMO

In addition to their canonical roles in regulating cell cycle transition and transcription, cyclin-dependent kinases (CDKs) have been shown to coordinate DNA damage response pathways, suggesting a rational pairing of CDK inhibitors with genotoxic chemotherapeutic agents in the treatment of human malignancies. Here, we report that roniciclib (BAY1000394), a potent pan-CDK inhibitor, displays promising anti-neoplastic activity as a single agent and potentiates cisplatin lethality in preclinical nasopharyngeal carcinoma (NPC) models. Proliferation of the NPC cell lines HONE-1, CNE-2, C666-1, and HK-1 was effectively curbed by roniciclib treatment, with IC50 values between 11 and 38 nmol/L. These anticancer effects were mediated by pleiotropic mechanisms consistent with successful blockade of cell cycle CDKs 1, 2, 3, and 4 and transcriptional CDKs 7 and 9, ultimately resulting in arrest at G1/S and G2/M, downregulation of the transcriptional apparatus, and repression of anti-apoptotic proteins. Considerably enhanced tumor cell apoptosis was achieved following combined treatment with 10 nmol/L roniciclib and 2.0 µmol/L cisplatin; this combination therapy achieved a response over 250% greater than either drug alone. Although roniciclib chemosensitized NPC cells to cisplatin, it did not sensitize untransformed (NP69) cells. The administration of 0.5 mg/kg roniciclib to BALB/c xenograft mice was well tolerated and effectively restrained tumor growth comparable to treatment with 6 mg/kg cisplatin, whereas combining these two agents produced far greater tumor suppression than either of the monotherapies. In summary, these data demonstrate that roniciclib has strong anti-NPC activity and synergizes with cisplatin chemotherapy at clinically relevant doses, thus justifying further evaluation of this combinatorial approach in clinical settings.

20.
Cancer Res ; 77(23): 6614-6626, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-28951465

RESUMO

Nasopharyngeal carcinoma (NPC) is an invasive cancer with particularly high incidence in Southeast Asia and Southern China. The pathogenic mechanisms of NPC, particularly those involving epigenetic dysregulation, remain largely elusive, hampering clinical management of this malignancy. To identify novel druggable targets, we carried out an unbiased high-throughput chemical screening and observed that NPC cells were highly sensitive to inhibitors of cyclin-dependent kinases (CDK), especially THZ1, a covalent inhibitor of CDK7. THZ1 demonstrated pronounced antineoplastic activities both in vitro and in vivo An integrative analysis using both whole-transcriptome sequencing and chromatin immunoprecipitation sequencing pinpointed oncogenic transcriptional amplification mediated by super-enhancers (SE) as a key mechanism underlying the vulnerability of NPC cells to THZ1 treatment. Further characterization of SE-mediated networks identified many novel SE-associated oncogenic transcripts, such as BCAR1, F3, LDLR, TBC1D2, and the long noncoding RNA TP53TG1. These transcripts were highly and specifically expressed in NPC and functionally promoted NPC malignant phenotypes. Moreover, DNA-binding motif analysis within the SE segments suggest that several transcription factors (including ETS2, MAFK, and TEAD1) may help establish and maintain SE activity across the genome. Taken together, our data establish the landscape of SE-associated oncogenic transcriptional network in NPC, which can be exploited for the development of more effective therapeutic regimens for this disease. Cancer Res; 77(23); 6614-26. ©2017 AACR.


Assuntos
Antineoplásicos/farmacologia , Carcinoma/genética , Carcinoma/patologia , Quinases Ciclina-Dependentes/antagonistas & inibidores , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/patologia , Fenilenodiaminas/farmacologia , Pirimidinas/farmacologia , Animais , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Carcinoma Nasofaríngeo , Proteína Proto-Oncogênica c-ets-2/genética , RNA Longo não Codificante/genética , Transcrição Gênica/efeitos dos fármacos , Transcrição Gênica/genética , Ensaios Antitumorais Modelo de Xenoenxerto , Quinase Ativadora de Quinase Dependente de Ciclina
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