Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
Int J Radiat Oncol Biol Phys ; 115(5): 1029, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36922078
2.
Artigo em Inglês | MEDLINE | ID: mdl-34765751

RESUMO

BACKGROUND: Radiation-induced hypothyroidism is a common toxicity of head and neck radiation. Our re-planning study aimed to reduce thyroid dose while maintaining target coverage with IMRT. METHODS: We retrospectively identified patients with oral-cavity (n = 5) and oropharyngeal cancer (n = 5). Treatment plans were re-optimized with 45 Gy thyroid mean dose constraint, then we cropped the thyroid out of PTVs and further reduced thyroid dose. Target coverage was delivering 100% dose to ≥ 93% of PTV and 95% of dose to > 99% of PTV. RESULTS: Originally, average mean dose to thyroid was 5580 cGy. In model I, this dropped to 4325 cGy (p < 0.0001). In model II, average mean dose was reduced to 3154 cGy (p < 0.0001). For PTV low and PTV int, all had acceptable target coverage. CONCLUSION: In patients with oral-cavity and oropharyngeal cancers, mean dose could be significantly reduced using a thyroid-optimized or thyroid-sparing IMRT technique with adequate coverage.

3.
Clin Case Rep ; 8(11): 2259-2264, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33235772

RESUMO

Bazex syndrome is a rare paraneoplastic dermatosis that precedes diagnosis of cancer. Awareness of this syndrome is important, as it allows early detection of underlying malignancy and may prevent misdiagnosis and delays in cancer treatment.

4.
Head Neck ; 42(9): 2405-2413, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32391626

RESUMO

BACKGROUND: Positron emission tomography/computed tomography (PET/CT) in staging of advanced oropharyngeal squamous cell carcinoma (OPSCC) and at 3 months posttreatment (PETpost) is often utilized to assess response. The significance of lymph node vs primary site treatment response is incompletely understood. METHODS: We reviewed 230 patients treated with radiation therapy. PETpost response was graded at primary and nodal sites and correlated with survival. RESULTS: Median age was 58, and 83% were p16-positive. Median follow-up was 24.3 months. Nodal response at PETpost predicted improved 2-year local recurrence-free survival (LRFS) (93% vs 72%, P =.004), 2-year disease-free survival (DFS) (80% vs 61.3%, P =.021), and 2-year overall survival (OS) (89% vs 83%, P =.051), while primary response only predicted improved 2-year LRFS (91% vs 76% P = .035). CONCLUSION: In OPSCC patients, both nodal and primary response at 3 months on PET/CT predicted for improved LRFS, but only nodal response predicted DFS and OS.


Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Neoplasias Orofaríngeas , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/diagnóstico por imagem , Carcinoma de Células Escamosas/radioterapia , Fluordesoxiglucose F18 , Humanos , Pessoa de Meia-Idade , Neoplasias Orofaríngeas/diagnóstico por imagem , Neoplasias Orofaríngeas/radioterapia , Prognóstico , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço
5.
Int J Cancer ; 147(1): 107-115, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31609479

RESUMO

For patients ineligible for cisplatin with definitive radiotherapy (CP-CRT) for locally advanced head and neck squamous cell carcinoma (LA-HNSCC), concurrent cetuximab (C225-RT) is a popular substitute. Carboplatin-based chemoradiation (CB-CRT) is another option; however, relative efficacies of CP-CRT, CB-CRT and C225-RT are unclear, particularly in the human papillomavirus (HPV)-unrelated population. We identified 316 patients with stage III-IVB cancers of the oropharynx (24.7%), larynx (58.2%) and hypopharynx (17.1%) undergoing definitive C225-RT (N = 61), CB-CRT (N = 74) or CP-CRT (N = 181). Kaplan-Meier and cumulative incidence functions were generated to estimate overall survival (OS), locoregional failure (LRF) and distant metastasis (DM). Cox proportional hazards were used to determine the association of survival endpoints with clinical characteristics. Respectively, 3-year cumulative incidences for CP-CRT, CB-CRT and C225-RT were: LRF (0.19, 0.18 and 0.48, p ≤ 0.001), DM (0.17, 0.12 and 0.25, p = 0.32). Kaplan-Meier estimates for 3 year OS were: CP-CRT: 71%; CB-CRT: 59% and C225-RT: 54%; p = 0.0094. CP-CRT (hazard ratio [HR] 0.336; 95% confidence interval [CI] 0.203-0.557, p < 0.01) and CB-CRT (HR 0.279; 95% CI 0.141-0.551, p < 0.01) were associated with reduced hazard for LRF on multivariable analysis. CP-CRT (HR 0.548; 95% CI 0.355-0.845, p < 0.01) and CB-CRT (HR 0.549; 95% CI 0.334-0.904, p = 0.02) were associated with a reduced hazard for death on multivariable analysis. Propensity matching confirmed reduced hazards with a combined CP/CB-CRT group compared to C225-RT for LRF: HR 0.384 (p = 0.018) and OS: HR 0.557 (p = 0.045) and CB-CRT group compared to C225-RT for LRF: HR 0.427 (p = 0.023). In conclusion, CB-CRT is an effective alternative to CP-CRT in HPV-unrelated LA-HNSCC with superior locoregional control and OS compared to C225-RT.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cetuximab/uso terapêutico , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/radioterapia , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Carcinoma de Células Escamosas de Cabeça e Pescoço/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carboplatina/administração & dosagem , Quimiorradioterapia , Cisplatino/administração & dosagem , Feminino , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Papillomaviridae , Infecções por Papillomavirus/patologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/virologia , Taxa de Sobrevida
6.
Oral Oncol ; 78: 46-51, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29496057

RESUMO

OBJECTIVES: to examine the impact of radiotherapy center volume on overall survival in patients with oral cavity and oropharyngeal squamous cell carcinoma getting adjuvant radiation therapy after receiving surgery at a high-volume center. MATERIALS AND METHODS: a retrospective study was conducted on patients with oral cavity squamous cell carcinoma or oropharyngeal squamous cell carcinoma treated surgically at a tertiary institution from 2000 to 2012 who received adjuvant radiotherapy. The outcome variable was overall survival and the independent variable was location of adjuvant radiation therapy: high-volume center (HVC) versus low-volume center (LVC). Cox proportional hazards models were used to assess associations between predictors of death. Variables that were found to be significant at the α = 0.10 were included in a multivariable model. RESULTS: 336 patients met inclusion criteria. One-hundred thirty-nine patients received adjuvant radiation therapy at HVC and 197 patients received adjuvant radiation therapy at LVC. A univariate Cox proportional hazards model identified the variables location, age, marital status, subsite, T stage, extracapsular extension, and smoking status to include in a multivariable model. Age, subsite, T stage, and extracapsular extension were independent predictors of overall survival (p < .05). Location (p = .55), marital status (p = .29), and smoking status (p = .22) were not statistically significant predictors of survival. CONCLUSION: After surgery at a HVC, the volume of adjuvant radiation therapy center was not significantly associated with overall survival. Significant predictors of survival included age, subsite, T stage, and extracapsular extension.


Assuntos
Carcinoma de Células Escamosas/radioterapia , Neoplasias Orofaríngeas/radioterapia , Radioterapia Adjuvante , Idoso , Carcinoma de Células Escamosas/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Orofaríngeas/patologia , Estudos Retrospectivos , Taxa de Sobrevida
7.
Oral Oncol ; 79: 9-14, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29598954

RESUMO

OBJECTIVES: Randomized trials evaluating cisplatin versus cetuximab chemoradiation (CRT) for p16+ oropharyngeal cancer (OPC) have yet to report preliminary data. Meanwhile, as a preemptive step toward morbidity reduction, the off-trial use of cetuximab in p16+ patients is increasing, even in those who could potentially tolerate cisplatin. The purpose of this study was to compare the efficacy of cisplatin versus cetuximab CRT in the treatment of p16+ OPC and to identify prognostic factors and predictors of tumor response. MATERIALS AND METHODS: Cases of p16+ OPC treated with cisplatin or cetuximab CRT at our institution from 2010 to 2014 were identified. Recursive partitioning analysis (RPA) classification was used to determine low-risk (LR-RPA) and intermediate-risk (IR-RPA) groups. Log-rank/Kaplan-Meier and Cox Regression methods were used to compare groups. RESULTS: We identified 205 patients who received cisplatin (n = 137) or cetuximab (n = 68) CRT in the definitive (n = 178) or postoperative (n = 27) setting. Median follow-up was 3 years. Cisplatin improved 3-year locoregional control (LRC) [92.7 vs 65.4%], distant metastasis-free survival (DMFS) [88.3 vs 71.2%], recurrence-free survival (RFS) [86.6 vs 50.6%], and overall survival (OS) [92.6 vs 72.2%] compared to cetuximab [all p < .001]. Concurrent cisplatin improved 3-year OS for LR-RPA (97.1 vs 80.3%, p < .001) and IR-RPA (97.1 vs 80.3%, p < .001) groupings. CONCLUSION: When treating p16+ OPC with CRT, the threshold for substitution of cisplatin with cetuximab should be maintained appropriately high in order to prolong survival times and optimize locoregional and distant tumor control. When cetuximab is used in cisplatin-ineligible patients, altered fractionation RT should be considered in an effort to improve LRC.


Assuntos
Antineoplásicos/uso terapêutico , Cetuximab/uso terapêutico , Quimiorradioterapia , Cisplatino/uso terapêutico , Genes p16 , Neoplasias Orofaríngeas/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Neoplasias Orofaríngeas/genética , Neoplasias Orofaríngeas/patologia , Prognóstico , Resultado do Tratamento , Adulto Jovem
8.
Laryngoscope ; 128(2): 403-411, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28771728

RESUMO

OBJECTIVES/HYPOTHESIS: To compare quality of life (QOL) of patients who underwent transoral robotic surgery (TORS) alone, with adjuvant radiation therapy (RT), or adjuvant chemoradiation therapy (CRT) in the treatment of oropharyngeal squamous cell cancer (OPSCCA). STUDY DESIGN: Prospective cohort study. METHODS: Medical records were reviewed for 111 patients treated for OPSCCA from 2008 to 2015. Patients were administered the Head and Neck Cancer Inventory (HNCI) to evaluate QOL preoperatively, and at 3 weeks, 3 months, 6 months, and 1 year postsurgery. QOL data were compared between 13 patients treated with TORS alone, 31 with adjuvant RT, and 67 with adjuvant CRT by a linear mixed effects model. RESULTS: Mean follow-up was 35 months. The HNCI response rates at 3 weeks and 3, 6, and 12 months were 80%, 60%, 55%, and 46%, respectively. TORS alone reported significantly higher eating scores than adjuvant RT or CRT at 3 and 6 months, and higher speech scores compared to adjuvant CRT at 3 months and adjuvant RT at 6 months. TORS alone and adjuvant RT reported less social disruption compared to adjuvant CRT at 3 months. Adjuvant CRT had consistently lower overall QOL scores until 6 months. No TORS-alone patient required percutaneous endoscopic gastrostomy, and no study patient required tracheostomy during treatment. CONCLUSIONS: TORS alone maintained higher QOL than adjuvant RT or CRT in eating, social function, speech, and overall QOL postsurgery. QOL and functional metrics were better for 6 months in TORS-alone patients, and at 12 months, the differences were not significant. LEVEL OF EVIDENCE: 4. Laryngoscope, 128:403-411, 2018.


Assuntos
Quimiorradioterapia Adjuvante/psicologia , Cirurgia Endoscópica por Orifício Natural/psicologia , Neoplasias Orofaríngeas/terapia , Qualidade de Vida , Procedimentos Cirúrgicos Robóticos/psicologia , Idoso , Quimiorradioterapia Adjuvante/métodos , Quimioterapia Adjuvante/métodos , Quimioterapia Adjuvante/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Boca/cirurgia , Cirurgia Endoscópica por Orifício Natural/métodos , Neoplasias Orofaríngeas/psicologia , Período Pós-Operatório , Estudos Prospectivos , Procedimentos Cirúrgicos Robóticos/métodos , Resultado do Tratamento
9.
Head Neck ; 39(7): 1405-1411, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28370900

RESUMO

BACKGROUND: The purpose of this study was to review long-term outcomes of sinonasal adenoid cystic carcinoma (ACC) and to clarify its association with human papillomavirus (HPV). METHODS: The medical records of 23 patients with sinonasal ACC treated with primary surgical resection between 1998 and 2013 were reviewed. Tissue specimens were available for 17 patients. The p16 testing was performed using immunohistochemistry (IHC), and HPV infection was determined using quantitative polymerase chain reaction (PCR) with primers targeting the E6/E7 region. RESULTS: Two of the 17 samples showed strong and diffuse p16 staining, whereas the remaining 15 cases showed p16-positivity isolated to the luminal cells. Only one of the p16-positive cases was positive for HPV. The 5-year local failure, disease-free survival (DFS), and overall survival (OS) were 51%, 52%, and 62%, respectively. CONCLUSION: Local failures are common with advanced sinonasal ACC, and the association of HPV with true sinonasal ACC is low.


Assuntos
Carcinoma Adenoide Cístico/terapia , Papillomaviridae/genética , Neoplasias dos Seios Paranasais/terapia , Neoplasias dos Seios Paranasais/virologia , Adulto , Idoso , Análise de Variância , Biópsia por Agulha , Carcinoma Adenoide Cístico/mortalidade , Carcinoma Adenoide Cístico/virologia , Estudos de Coortes , Terapia Combinada , Intervalos de Confiança , DNA Viral/análise , Intervalo Livre de Doença , Feminino , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Otorrinolaringológicos/métodos , Papillomaviridae/isolamento & purificação , Neoplasias dos Seios Paranasais/mortalidade , Prognóstico , Radioterapia Adjuvante , Estudos Retrospectivos , Medição de Risco , Análise de Sobrevida , Resultado do Tratamento , Adulto Jovem
10.
J Am Coll Radiol ; 8(11): 785-8, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22051463

RESUMO

PURPOSE: The aim of this study was to assess current practices, strengths, and deficiencies in the orientation process for incoming radiation oncology (RO) residents. METHODS: An institutional review board-approved anonymous survey was distributed electronically to RO residents in postgraduate years 2 to 5 and those in their first postgraduate years. Questions were included on the type and utility of orientation materials received by residents before and upon entering RO residency. RESULTS: Responses were received from 25.3% of all current and recent residents. Most residents (81.3%) had 2 or 3 months of prior experience rotating in clinical RO. Orientation materials in RO were received by 74.1% of residents before starting residency. An orientation at the start of RO residency was received by 95.4% of RO residents. Orientation length was <1 hour in 2.8%, 1 hour to a half day in 7.8%, more than a half day but <1 full day in 21.8%, >1 full day but <1 week in 45.8%, and >1 week but <1 month in 20.1%. Almost half of RO residents (48.4%) felt that an RO orientation was essential, but only 11.3% of residents felt that their orientation programs were essential. A statistically significant Spearman's correlation was observed between programs with longer orientation and increased helpfulness of orientation (ρ = 0.26, P = .008). Residents with more components in their onsite orientations felt that their orientations were more helpful (ρ = 0.407, P < .001). CONCLUSIONS: Radiation oncology residents could benefit from a more comprehensive orientation, including a broader array of materials sent to incoming residents for their review before starting residency and a more extensive onsite orientation.


Assuntos
Competência Clínica , Currículo , Internato e Residência/organização & administração , Radioterapia (Especialidade)/educação , Inquéritos e Questionários , Adulto , Estudos Transversais , Educação de Pós-Graduação em Medicina/organização & administração , Feminino , Humanos , Masculino , Avaliação das Necessidades , Avaliação de Programas e Projetos de Saúde , Radiologia/educação , Estados Unidos
11.
Am J Clin Oncol ; 34(1): 53-7, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20216303

RESUMO

OBJECTIVES: To investigate the change in creatinine clearance (CrCl) over time following upper abdominal radiation utilizing a dose-volume histogram (DVH) multivariate analysis. METHODS: The study population included 125 patients with gastrointestinal malignancy treated with abdominal radiation therapy at our institution between 1994 and 2006, with available creatinine and DVH information. Kidney dose-volume data collected included mean kidney dose, volume of kidney irradiated, V5, V10, and V20 of total kidney volume, and number of mL of kidney greater than and less than 20 Gy. RESULTS: With a median follow-up of 2.4 years, and a mean kidney dose of 16.2 Gy, a significant correlation between decrease in CrCl and irradiated kidney volume observed was noted for all DVH parameters. The strongest correlations were found when using V5, V10, and number of mL of kidney treated to greater than 20 Gy. There was no significant change in number of antihypertensive medications taken by patients over time, and no relationship between outcome variables and pre-existing comorbidities. CONCLUSIONS: This is the first study that we are aware of comparing DVH data with measurement of renal toxicity. We show significant correlations between dose and volume irradiated and decline in renal function. This will be clinically useful when determining a treatment plan for patients with borderline preradiation CrCl and provides evidence that minimizing radiation to the kidney could have important clinical ramifications.


Assuntos
Creatinina/metabolismo , Neoplasias Gastrointestinais/radioterapia , Rim/metabolismo , Rim/efeitos da radiação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Neoplasias Gastrointestinais/metabolismo , Humanos , Testes de Função Renal , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Lesões por Radiação/etiologia , Lesões por Radiação/metabolismo , Dosagem Radioterapêutica , Taxa de Sobrevida , Resultado do Tratamento , Adulto Jovem
12.
Pract Radiat Oncol ; 1(3): 196-203, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-24673950

RESUMO

The treatment of endometrial cancer begins with surgery, including total abdominal hysterectomy, bilateral salpingo-oophorectomy, peritoneal lavage, and a consideration for lymph node evaluation. Selection of adjuvant therapy is based on an approximation of the risk of recurrence with features such as stage, tumor histology, lymphovascular space invasion, and patient age. The role of adjuvant radiation therapy in patients with intermediate risk of recurrence is a matter of ongoing controversy. Several randomized trials indicate that adjuvant radiation therapy improves loco-regional control. However, the ideal form of radiation therapy in these patients continues to be under debate.

13.
Oncology (Williston Park) ; 23(4): 342-9, 2009 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-19476264

RESUMO

Endometrial cancer treatment ideally begins with a staging procedure including abdominopelvic washing, total abdominal hysterectomy, bilateral salpingo-oophorectomy, and lymph node evaluation. Recommendations for postoperative adjuvant radiotherapy are determined by recurrence risk. Patients who have undergone staging and have early stage I disease and an absence of high-risk features for recurrence generally are treated with surgery alone. Intermediate-risk patients--those with high-risk stage I disease and some stage II patients--may benefit from adjuvant radiation therapy. Several randomized trials show that radiation therapy improves locoregional control among intermediate-risk patients. The optimal type of radiation therapy, whether vaginal brachytherapy or whole-pelvic radiation therapy, remains undetermined, though treatment decision can be guided by risk factors not encompassed by the current staging system. Patients with high-risk stage II disease and stage III disease generally receive external-beam radiotherapy, often in combination with chemotherapy. Chemotherapy alone in advanced-stage patients is a consideration, given the results of the Gynecologic Oncology Group (GOG)-122 trial.


Assuntos
Neoplasias do Endométrio/radioterapia , Neoplasias do Endométrio/cirurgia , Histerectomia , Ovariectomia , Quimioterapia Adjuvante , Neoplasias do Endométrio/mortalidade , Neoplasias do Endométrio/patologia , Medicina Baseada em Evidências , Feminino , Humanos , Estadiamento de Neoplasias , Seleção de Pacientes , Radioterapia Adjuvante/efeitos adversos , Recidiva , Medição de Risco , Resultado do Tratamento
14.
J Biol Chem ; 280(24): 23094-102, 2005 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-15805112

RESUMO

p73 is a member of the p53 gene family, which also includes p53 and p63. These proteins share sequence similarity and target genes but also have divergent roles in cancer and development. Unlike p53, transcription of the p73 gene yields multiple full-length (transactivation (TA) domain) and amino terminus-truncated (DeltaN) isoforms. DeltaNp73 acts in a dominant negative fashion to inhibit the actions of TAp73 and p53 on their target genes, promoting cell survival and proliferation and suppressing apoptosis. The balance between TAp73 and its negative regulator, DeltaNp73, may therefore represent an important determinant of developmental cell fate. There is little if anything known regarding the developmental regulation of the p73 gene. In this study, we showed that TAp73 and DeltaNp73 exhibit reciprocal spatiotemporal expression and functions during nephrogenesis. TAp73 was predominantly expressed in the differentiation domain of the renal cortex in an overlapping manner with the vasopressin-sensitive water channel aquaporin-2 (AQP-2). Chromatin immunoprecipitation assays demonstrated that the endogenous AQP-2 promoter was occupied by TAp73 in a developmentally regulated manner. Furthermore TAp73 stimulated AQP-2 promoter-driven reporter expression. TAp73 also activated the bradykinin B2 receptor (B2R) promoter, a developmentally regulated gene involved in regulation of sodium excretion. The transcriptional effects of TAp73 on AQP-2 and B2R were independent of p53. In marked contrast to TAp73, DeltaNp73 isoforms were induced early in development and were preferentially expressed in proliferating nephron precursors. Moreover DeltaNp73 was a potent repressor of B2R gene transcription. We conclude that the p73 gene is developmentally regulated during kidney organogenesis. The spatiotemporal switch from DeltaNp73 to TAp73 may play an important role in the terminal differentiation program of the developing nephron.


Assuntos
Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Genes Supressores de Tumor/fisiologia , Rim/crescimento & desenvolvimento , Rim/metabolismo , Proteínas Nucleares/química , Proteínas Nucleares/fisiologia , Animais , Animais Recém-Nascidos , Aquaporina 2 , Aquaporinas/química , Aquaporinas/metabolismo , Western Blotting , Diferenciação Celular , Linhagem da Célula , Proliferação de Células , Sobrevivência Celular , Imunoprecipitação da Cromatina , Proteínas de Ligação a DNA/biossíntese , Relação Dose-Resposta a Droga , Éxons , Genes Reporter , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Microscopia de Fluorescência , Modelos Genéticos , Proteínas Nucleares/biossíntese , Regiões Promotoras Genéticas , Ligação Proteica , Isoformas de Proteínas , Estrutura Terciária de Proteína , Ratos , Receptor B2 da Bradicinina/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Transcrição Gênica , Transfecção , Proteína Tumoral p73 , Proteínas Supressoras de Tumor , Água/química
15.
J Biol Chem ; 277(48): 45715-8, 2002 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-12364342

RESUMO

Smac (second mitochondrial activator of caspases) is released from the mitochondria during apoptosis to relieve inhibition of caspases by the inhibitor of apoptosis proteins (IAPs). The release of Smac antagonizes several IAPs and assists the initiator caspase-9 and effector caspases (caspase-3, caspase-6, and caspase-7) in becoming active, ultimately leading to death of the cell. Translocation of Smac along with cytochrome c and other mitochondrial pro-apoptotic proteins represent important regulatory checkpoints for mitochondria-mediated apoptosis. Whether Smac and cytochrome c translocate by the same mechanism is not known. Here, we show that the time required for Smac efflux from the mitochondria of cells subjected to staurosporine-induced apoptosis is approximately four times longer than the time required for cytochrome c efflux. These results suggest that Smac and cytochrome c may exit the mitochondria by different pathways.


Assuntos
Proteínas de Transporte/metabolismo , Citosol/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Apoptose , Proteínas Reguladoras de Apoptose , Proteínas de Bactérias/metabolismo , Ciclo Celular , Grupo dos Citocromos c/metabolismo , Células HeLa , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Cinética , Proteínas Luminescentes/metabolismo , Transporte Proteico , Proteínas Recombinantes de Fusão/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA