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1.
Eur Radiol ; 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38514481

RESUMO

OBJECTIVES: This study aimed to construct a radiomics-based model for prognosis and benefit prediction of concurrent chemoradiotherapy (CCRT) versus intensity-modulated radiotherapy (IMRT) in locoregionally advanced nasopharyngeal carcinoma (LANPC) following induction chemotherapy (IC). MATERIALS AND METHODS: A cohort of 718 LANPC patients treated with IC + IMRT or IC + CCRT were retrospectively enrolled and assigned to a training set (n = 503) and a validation set (n = 215). Radiomic features were extracted from pre-IC and post-IC MRI. After feature selection, a delta-radiomics signature was built with LASSO-Cox regression. A nomogram incorporating independent clinical indicators and the delta-radiomics signature was then developed and evaluated for calibration and discrimination. Risk stratification by the nomogram was evaluated with Kaplan-Meier methods. RESULTS: The delta-radiomics signature, which comprised 19 selected features, was independently associated with prognosis. The nomogram, composed of the delta-radiomics signature, age, T category, N category, treatment, and pre-treatment EBV DNA, showed great calibration and discrimination with an area under the receiver operator characteristic curve of 0.80 (95% CI 0.75-0.85) and 0.75 (95% CI 0.64-0.85) in the training and validation sets. Risk stratification by the nomogram, excluding the treatment factor, resulted in two groups with distinct overall survival. Significantly better outcomes were observed in the high-risk patients with IC + CCRT compared to those with IC + IMRT, while comparable outcomes between IC + IMRT and IC + CCRT were shown for low-risk patients. CONCLUSION: The radiomics-based nomogram can predict prognosis and survival benefits from concurrent chemotherapy for LANPC following IC. Low-risk patients determined by the nomogram may be potential candidates for omitting concurrent chemotherapy during IMRT. CLINICAL RELEVANCE STATEMENT: The radiomics-based nomogram was constructed for risk stratification and patient selection. It can help guide clinical decision-making for patients with locoregionally advanced nasopharyngeal carcinoma following induction chemotherapy, and avoid unnecessary toxicity caused by overtreatment. KEY POINTS: • The benefits from concurrent chemotherapy remained controversial for locoregionally advanced nasopharyngeal carcinoma following induction chemotherapy. • Radiomics-based nomogram achieved prognosis and benefits prediction of concurrent chemotherapy. • Low-risk patients defined by the nomogram were candidates for de-intensification.

2.
BMJ ; 380: e072133, 2023 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-36746459

RESUMO

OBJECTIVES: To address whether sparing the medial retropharyngeal lymph node (MRLN) region from elective irradiation volume provides non-inferior local relapse-free survival versus standard radiotherapy in patients with nasopharyngeal carcinoma. DESIGN: Open-label, non-inferiority, multicentre, randomised, phase 3 trial. SETTING: Three Chinese hospitals between 20 November 2017 and 3 December 2018. PARTICIPANTS: Adults (18-65 years) with newly diagnosed, non-keratinising, non-distant metastatic nasopharyngeal carcinoma without MRLN involvement. INTERVENTIONS: Randomisation was done centrally by the Clinical Trials Centre at Sun Yat-sen University Cancer Center. Eligible patients were randomly assigned (1:1; block size of four) to receive MRLN sparing radiotherapy or standard radiotherapy (both medial and lateral retropharyngeal lymph node groups), and stratified by institution and treatment modality as follows: radiotherapy alone; concurrent chemoradiotherapy; induction chemotherapy plus radiotherapy or concurrent chemoradiotherapy. MAIN OUTCOME MEASURES: Non-inferiority was met if the lower limit of the one sided 97.5% confidence interval of the absolute difference in three year local relapse-free survival (MRLN sparing radiotherapy minus standard radiotherapy) was greater than -8%. RESULTS: 568 patients were recruited: 285 in the MRLN sparing radiotherapy group; 283 in the standard radiotherapy group. Median follow-up was 42 months (interquartile range 39-45), intention-to-treat analysis showed that the three year local relapse-free survival of the MRLN sparing radiotherapy group was non-inferior to that of the standard radiotherapy group (95.3% v 95.5%, stratified hazard ratio 1.04 (95% confidence interval 0.51 to 2.12), P=0.95) with a difference of -0.2% ((one sided 97.5% confidence interval -3.6 to ∞), Pnon-inferiority<0.001). In the safety set (n=564), the sparing group had a lower incidence of grade ≥1 acute dysphagia (25.5% v 35.1%, P=0.01) and late dysphagia (24.0% v 34.3%, P=0.008). Patient reported outcomes at three years after MRLN sparing radiotherapy were better in multiple domains after adjusting for the baseline values: global health status (mean difference -5.6 (95% confidence interval -9.1 to -2.0), P=0.002), role functioning (-5.5 (-7.4 to -3.6), P<0.001), social functioning (-6.2 (-8.9 to -3.6), P<0.001), fatigue (7.9 (4.0 to 11.8), P<0.001), and swallowing (11.0 (8.4 to 13.6), P<0.001). The difference in swallowing scores reached clinical significance (>10 points difference). CONCLUSION: Compared with standard radiotherapy, MRLN sparing radiotherapy showed non-inferiority in terms of risk of local relapse with fewer radiation related toxicity and improved patient reported outcomes in patients with non-metastatic nasopharyngeal carcinoma. TRIAL REGISTRATION: ClinicalTrials.gov NCT03346109.


Assuntos
Transtornos de Deglutição , Neoplasias Nasofaríngeas , Adulto , Humanos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linfonodos/patologia , Carcinoma Nasofaríngeo/radioterapia , Neoplasias Nasofaríngeas/radioterapia , Neoplasias Nasofaríngeas/patologia , Recidiva Local de Neoplasia/radioterapia
3.
Curr Res Food Sci ; 5: 1732-1739, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36247332

RESUMO

Heterocyclic amines (HCAs) are a group of carcinogenic substances produced in protein-rich poultry meat under high-temperature. Enzymatic acylation of anthocyanins (ACNs) is a reliable way to improve their stability, and we recently found the acylated cyaniding-3-O-glucose (cyanidin-3-6-cinnamoyl-glucoside, C3(6C)G) could effective inhibit the HCAs formation, but the underline mechanism was still obscure. Thus, the present study investigated the inhibitory effect ofC3(6C)G on HCAs formation in the food system (chicken breast) and to explore the potential mechanism. The results showed that C3(6C)G with different concentrations (0.1, 0.5 and 1.0 mg/mL) could significantly inhibit lipid oxidation and decrease the total HCAs content (P<0.05) in chicken breast meat patty after roasting. The samples with 0.1 mg/mL C3(6C)G had the best inhibition effect on total HCAs, with an inhibition rate of 28%, and the inhibition rates for IQ, Harman, TRP-P-2, PhIP and AαC were 34%, 46%, 100%, 54% and 41%, respectively.

4.
Ecotoxicol Environ Saf ; 242: 113921, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35908531

RESUMO

Oocyte quality is essential for a successful pregnancy. 1-Nitropyrene (1-NP) is a widely distributed pollutant in the environment and is well-known for its mutagenicity and carcinogenicity. However, whether 1-NP has toxic effects on mammalian oocyte quality remains unknown. In the present study, we focused on the effect of 1-NP on oocyte maturation using mouse oocytes as an in vitro model. Our study showed that 1-NP exposure disrupted the meiotic spindle assembly and caused chromosome misalignment, further impaired first polar body extrusion, and significantly decreased the fertilization capability in mouse oocytes. Further investigation showed that the mitochondrial membrane potential (MMP) and ATP levels were decreased, and the expression of genes encoding components of the mitochondrial respiratory chain was inhibited in 1-NP exposed oocytes. Meanwhile, 1-NP exposure increased the levels of reactive oxygen species (ROS), inhibited the expression of genes encoding antioxidant enzymes, and increased the frequency of early apoptotic oocytes. Overall, our data suggest that 1-NP exposure disrupts mitochondrial function and intracellular redox balance, ultimately impairing oocyte maturation. These findings reveal the adverse effect of 1-NP exposure on oocyte quality.


Assuntos
Apoptose , Oogênese , Animais , Feminino , Mamíferos/metabolismo , Camundongos , Mitocôndrias , Oócitos , Estresse Oxidativo , Gravidez , Pirenos , Espécies Reativas de Oxigênio/metabolismo
5.
Radiother Oncol ; 157: 114-121, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33516790

RESUMO

BACKGROUND AND PURPOSE: To explore the prognostic value of different radiologic extranodal extension (rENE) grades and their potential improvement for the 8th edition N category in nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: From 2009 to 2013, a cohort of 1887 patients with NPC was retrospectively enrolled and randomized to the training (n = 955) and validation (n = 932) groups. rENE was categorized as follows: grade 0, nodes without rENE; grade 1, nodes with rENE infiltrating the surrounding fat only; grade 2, matted nodes; grade 3, nodes with rENE infiltrating adjacent structures. RESULTS: The percentage of patients with MRI-positive cervical nodes was 66.5% (1254/1887), of whom grade 0, 1, 2 and 3 rENE cases accounted for 33.2% (416/1254), 14.9% (187/1254), 36.5% (458/1254) and 15.4% (193/1254), respectively. The kappa coefficients for the inter-rater and intra-rater assessments were 0.63, 0.51, 0.65 and 0.93, and 0.76, 0.69, 0.72 and 1.0 in grade 0, 1, 2 and 3 rENE, respectively. Grade 3 rENE rather than grades 0-2 rENE was an independent unfavorable predictor of overall survival and disease-free survival (P < 0.001). Recursive partitioning analysis was applied to refine the N category: eN0 (N0), eN1 (N1 without grade 3), eN2 (N2 without grade 3), and eN3 (N1/N2 with grade 3, N3). Compared to the current system, the proposed N category performed better in hazard consistency, hazard discrimination, sample size balance and outcome prediction. CONCLUSION: Grade 3 rENE was an independent unfavorable indicator of NPC. Upstaging patients in N1-2 with grade 3 rENE to N3 led to a superior prognostic performance.


Assuntos
Extensão Extranodal , Neoplasias Nasofaríngeas , Humanos , Imageamento por Ressonância Magnética , Carcinoma Nasofaríngeo/diagnóstico por imagem , Carcinoma Nasofaríngeo/patologia , Neoplasias Nasofaríngeas/diagnóstico por imagem , Neoplasias Nasofaríngeas/patologia , Neoplasias Nasofaríngeas/radioterapia , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos
7.
J Clin Endocrinol Metab ; 105(10)2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32772095

RESUMO

CONTEXT: Premature ovarian insufficiency (POI) is characterized by cessation of menstruation before 40 years of age and elevated serum level of FSH (>25 IU/L). Recent studies have found a few causative genes responsible for POI enriched in meiotic recombination and DNA damage repair pathways. OBJECTIVE: To investigate the role of variations in homologous recombination genes played in POI pathogenesis. METHODS: The whole exome sequencing was performed in 50 POI patients with primary amenorrhea. Functional characterizations of the novel variants were carried out in budding yeast and human cell line. RESULTS: We identified 8 missense variants in 7 homologous recombination genes, including EXO1, RAD51, RMI1, MSH5, MSH2, MSH6, and MLH1. The mutation p.Thr52Ser in EXO1 impaired the meiotic process of budding yeast and p.Glu68Gly in RAD51-altered protein localization in human cells, both of them impaired the efficiency of homologous recombination repair for DNA double-stranded breaks in human cells. CONCLUSIONS: Our study first linked the variants of EXO1 and RAD51 with POI and further highlighted the role of DNA repair genes in ovarian dysgenesis.


Assuntos
Enzimas Reparadoras do DNA/genética , Exodesoxirribonucleases/genética , Recombinação Homóloga/genética , Rad51 Recombinase/genética , Adulto , Análise Mutacional de DNA , Feminino , Humanos , Mutação de Sentido Incorreto , Insuficiência Ovariana Primária/genética , Sequenciamento do Exoma
8.
Biomed Res Int ; 2020: 8068913, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32149139

RESUMO

We aimed to assess the use of automatic machine learning (AutoML) algorithm based on magnetic resonance (MR) image data to assign prediction scores to patients with nasopharyngeal carcinoma (NPC). We also aimed to develop a 4-group classification system for NPC, superior to the current clinical staging system. Between January 2010 and January 2013, 792 patients with recent diagnosis of NPC, who had MR image data, were enrolled in the study. The AutoML algorithm was used and all statistical analyses were based on the 10-fold test. Primary endpoints included the probabilities of overall survival (OS), distant metastasis-free survival (DMFS), and local-region relapse-free survival (LRFS), and their sum was recorded as the final voting score, representative of progression-free survival (PFS) for each patient. The area under the receiver operating characteristic (ROC) curve generated from the MR image data-based model compared with the tumor, node, and metastasis (TNM) system-based model was 0.796 (P=0.008) for OS, 0.752 (P=0.053) for DMFS, and 0.721 (P=0.025) for LRFS. The Kaplan-Meier (KM) test values for II/I, III/II, IV/III groups in our new machine learning-based scoring system were 0.011, 0.010, and <0.001, respectively, whereas those for II/I, III/II, IV/III groups in the TNM/American Joint Committee on Cancer (AJCC) system were 0.118, 0.121, and <0.001, respectively. Significant differences were observed in the new machine learning-based scoring system analysis of each curve (P < 0.05), whereas the P values of curves obtained from the TNM/AJCC system, between II/I and III/II, were 0.118 and 0.121, respectively, without a significant difference. In conclusion, the AutoML algorithm demonstrated better prognostic performance than the TNM/AJCC system for NPC. The algorithm showed a good potential for clinical application and may aid in improving counseling and facilitate the personalized management of patients with NPC. The clinical application of our new scoring and staging system may significantly improve precision medicine.


Assuntos
Interpretação de Imagem Assistida por Computador/métodos , Aprendizado de Máquina , Imageamento por Ressonância Magnética/métodos , Carcinoma Nasofaríngeo/diagnóstico por imagem , Neoplasias Nasofaríngeas/diagnóstico por imagem , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nasofaringe/diagnóstico por imagem , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos
9.
Eur Radiol ; 30(4): 2115-2124, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31811429

RESUMO

OBJECTIVES: This study aimed to evaluate the value of nodal grouping (NG), defined as the presence of at least three contiguous lymph nodes (LNs) within one LN region, in staging and management of patients with non-metastatic nasopharyngeal carcinoma (NPC). METHODS: MR images were reviewed to evaluate LN variables, including NG. The Kaplan-Meier method and multivariate Cox regression models evaluated the association between the variables and survival. Harrell's concordance index (C-index) was used to measure the performance of prognostic models. The outcome of induction chemotherapy (IC) in patients with and without NG was compared using matched-pair analysis. RESULTS: In 1224 patients enrolled, NG was found to be an independent prognostic factor for overall survival (OS), progression-free survival (PFS), distant metastasis-free survival (DMFS), and regional recurrence-free survival. The hazard ratio and 95% confidence interval (CI) of NG for OS (3.86, 2.09-7.12) were higher than those of stage N2 (3.54, 1.89-6.70). On upgrading patients with NG from stages N1 to N2, the revised N staging yielded a higher C-index compared to the American Joint Committee on Cancer system in predicting PFS (0.664 vs. 0.658, p = 0.022) and DMFS (0.699 vs. 0.690, p = 0.005). Results of the matched-pair analysis revealed that for patients with NG in stages N1 and N2, IC was correlated with improved OS (p = 0.022), PFS (p = 0.007), and DMFS (p = 0.021). CONCLUSIONS: NG is a significant prognostic factor for patients with NPC. Patients with NG may be upgraded from stages N1 to N2. NG was also a marker for identifying patients who would benefit from IC. KEY POINTS: • Nodal grouping, defined as the presence of at least three contiguous LNs within one LN region on MRI, was identified as a significant prognostic factor. • In patients with nasopharyngeal carcinoma, nodal grouping may influence lymph node staging. • Nodal grouping was a marker for identifying patients who may benefit from induction chemotherapy.


Assuntos
Quimioterapia de Indução/métodos , Linfonodos/patologia , Imageamento por Ressonância Magnética/métodos , Carcinoma Nasofaríngeo/classificação , Neoplasias Nasofaríngeas/classificação , Estadiamento de Neoplasias , Adulto , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/tratamento farmacológico , Carcinoma Nasofaríngeo/secundário , Neoplasias Nasofaríngeas/diagnóstico , Neoplasias Nasofaríngeas/tratamento farmacológico , Prognóstico , Intervalo Livre de Progressão , Estudos Retrospectivos
10.
Head Neck ; 41(12): 4088-4097, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31518030

RESUMO

BACKGROUND: To investigate the prognostic significance of paranasal sinus invasion in nasopharyngeal carcinoma (NPC) patients. METHODS: Patients with NPC after intensity-modulated radiotherapy from 2010 to 2013 were identified (n = 1225). Clinical features and magnetic resonance images were analyzed. RESULTS: Paranasal sinus invasion was identified in 182/1225 patients (14.9%). Multivariate analysis showed that paranasal sinus invasion was an independent factor for overall survival, progression-free survival, distant metastasis-free survival, and local recurrence-free survival (P < .05 for all). T3 NPC patients with paranasal sinus invasion had a poorer prognosis than those without (P < .05), and there was no significant survival difference compared with T4 patients, regardless of involvement of inner structures (P > .05 for all). Upgrading NPC with paranasal sinus invasion to T4 disease achieved better predictive abilities. CONCLUSIONS: Paranasal sinus invasion is an independent prognostic factor for NPC. It may be appropriate to upgrade the T classification.


Assuntos
Carcinoma Nasofaríngeo/patologia , Neoplasias Nasofaríngeas/patologia , Invasividade Neoplásica/patologia , Seios Paranasais/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Carcinoma Nasofaríngeo/diagnóstico , Carcinoma Nasofaríngeo/mortalidade , Carcinoma Nasofaríngeo/radioterapia , Neoplasias Nasofaríngeas/diagnóstico , Neoplasias Nasofaríngeas/mortalidade , Neoplasias Nasofaríngeas/radioterapia , Estadiamento de Neoplasias , Prognóstico , Radioterapia de Intensidade Modulada , Estudos Retrospectivos , Taxa de Sobrevida , Adulto Jovem
11.
Radiother Oncol ; 140: 90-97, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31195216

RESUMO

BACKGROUND AND PURPOSE: Metastasis laterality is used for N classification of cervical lymph nodes, but not retropharyngeal lymph nodes (RLNs). This study explored the prognostic value of laterality of RLN metastasis to provide suggestions for a better N standard classification. MATERIALS AND METHODS: This retrospective study evaluated 1225 patients with new biopsy-confirmed nasopharyngeal carcinoma (NPC). Univariable and multivariable Cox regression models were used to assess overall survival (OS), progression-free survival (PFS), and distant metastasis-free survival (DMFS). A new N classification system was developed and compared to the 8th AJCC system. Kaplan-Meier methods with log-rank tests were used to compare OS, PFS, and DMFS between our proposed N stage and the AJCC N stages. RESULTS: The incidence of RLN metastasis was 38.7% (unilateral) and 27.5% (bilateral). In the N1 subgroup, metastasis laterality was associated with significant differences in the 5-year rates of OS (89.4% vs. 82.6%, p = 0.016), DMFS (91.5% vs. 82.9%, p = 0.004), and PFS (80.3% vs. 71.2%, p = 0.016). However, no significant differences in these outcomes were observed when we compared N2 disease to N1 bilateral RLN metastasis. Multivariate analysis confirmed that bilateral RLN metastasis independently predicted OS, DMFS, and PFS. The proposed classification broadened the differences in OS, DMFS, PFS between N1 and N2 disease. CONCLUSION: Patients with NPC and unilateral RLN metastasis had better survival than did patients with bilateral RLN metastasis. Upgrading cases with bilateral RLN metastasis from N1 to N2 may help improve prognostication using the 8th AJCC system.


Assuntos
Carcinoma Nasofaríngeo/patologia , Neoplasias Nasofaríngeas/patologia , Adulto , Idoso , Feminino , Humanos , Metástase Linfática/patologia , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/mortalidade , Neoplasias Nasofaríngeas/mortalidade , Estadiamento de Neoplasias , Faringe/patologia , Prognóstico , Intervalo Livre de Progressão , Estudos Retrospectivos
12.
Sci Signal ; 5(212): ra16, 2012 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-22355189

RESUMO

The threat of a new influenza pandemic has existed since 1997, when the highly pathogenic H5N1 strain of avian influenza A virus infected humans in Hong Kong and spread across Asia, where it continued to infect poultry and people. The human mortality rate of H5N1 infection is about 60%, whereas that of seasonal H1N1 infection is less than 0.1%. The high mortality rate associated with H5N1 infection is predominantly a result of respiratory failure caused by acute lung injury; however, how viral infection contributes to this disease pathology is unclear. Here, we used electron microscopy to show the accumulation of autophagosomes in H5N1-infected lungs from a human cadaver and mice, as well as in infected A549 human epithelial lung cells. We also showed that H5N1, but not seasonal H1N1, induced autophagic cell death in alveolar epithelial cells through a pathway involving the kinase Akt, the tumor suppressor protein TSC2, and the mammalian target of rapamycin. Additionally, we suggest that the hemagglutinin protein of H5N1 may be responsible for stimulating autophagy. When applied prophylactically, reagents that blocked virus-induced autophagic signaling substantially increased the survival rate of mice and substantially ameliorated the acute lung injury and mortality caused by H5N1 infection. We conclude that the autophagic cell death of alveolar epithelial cells likely plays a crucial role in the high mortality rate of H5N1 infection, and we suggest that autophagy-blocking agents might be useful as prophylactics and therapeutics against infection of humans by the H5N1 virus.


Assuntos
Autofagia/fisiologia , Virus da Influenza A Subtipo H5N1 , Influenza Humana/patologia , Pulmão/ultraestrutura , Transdução de Sinais/fisiologia , Análise de Variância , Animais , Autofagia/efeitos dos fármacos , Proteína 5 Relacionada à Autofagia , Western Blotting , Linhagem Celular , Primers do DNA/genética , Células Epiteliais/fisiologia , Técnicas de Silenciamento de Genes , Glicoproteínas de Hemaglutininação de Vírus da Influenza/administração & dosagem , Glicoproteínas de Hemaglutininação de Vírus da Influenza/farmacologia , Humanos , Pulmão/virologia , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica , Proteínas Associadas aos Microtúbulos/genética , Proteína Oncogênica v-akt/metabolismo , Fagossomos/patologia , Reação em Cadeia da Polimerase em Tempo Real , Serina-Treonina Quinases TOR/metabolismo , Proteína 2 do Complexo Esclerose Tuberosa , Proteínas Supressoras de Tumor/metabolismo
13.
Virus Res ; 136(1-2): 8-15, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18554741

RESUMO

Cell entry of severe acute respiratory syndrome coronavirus (SARS-CoV) is mediated by the viral spike (S) protein. Amino acids 319-510 on the S protein have been mapped as the receptor-binding domain (RBD), which mediates binding to the SARS-CoV receptor angiotensin converting enzyme 2 (ACE2) on SARS-CoV susceptible cells. In this study, we expressed a fusion protein containing the human codon-optimized RBD of the SARS-CoV spike protein linked to the Fc portion of human IgG1 (named RBD-Fc) in HEK293 cells. The RBD-Fc protein was purified by affinity chromatography. The flow cytometry assay showed that the purified RBD-Fc protein could bind to ACE2. We demonstrated that the RBD spike protein alone could be internalized into SARS-CoV susceptible cells together with ACE2. We also showed that the removal of N-glycans from the RBD spike protein did not abolish this phenomenon. Our discoveries may have some implications for the development of the SARS vaccine.


Assuntos
Endocitose , Glicoproteínas de Membrana/metabolismo , Peptidil Dipeptidase A/metabolismo , Receptores Virais/metabolismo , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/fisiologia , Proteínas do Envelope Viral/metabolismo , Enzima de Conversão de Angiotensina 2 , Animais , Linhagem Celular , Chlorocebus aethiops , Citometria de Fluxo , Humanos , Fragmentos Fc das Imunoglobulinas/genética , Glicoproteínas de Membrana/genética , Ligação Proteica , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Glicoproteína da Espícula de Coronavírus , Proteínas do Envelope Viral/genética
14.
Plant Mol Biol ; 60(4): 533-54, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16525890

RESUMO

In yeast, Rad21/Scc1 and its meiotic variant Rec8 are key players in the establishment and subsequent dissolution of sister chromatid cohesion for mitosis and meiosis, respectively, which are essential for chromosome segregation. Unlike yeast, our identification revealed that the rice genome has 4 RAD21-like genes that share lower than 21% identity at polypeptide levels, and each is present as a single copy in this genome. Here we describe our analysis of the function of OsRAD21-4 by RNAi. Western blot analyses indicated that the protein was most abundant in young flowers and less in leaves and buds but absent in roots. In flowers, the expression was further defined to premeiotic pollen mother cells (PMCs) and meiotic PMCs of anthers. Meiotic chromosome behaviors were monitored from male meiocytes of OsRAD21-4-deficient lines mediated by RNAi. The male meiocytes showed multiple aberrant events at meiotic prophase I, including over-condensation of chromosomes, precocious segregation of homologues and chromosome fragmentation. Fluorescence in situ hybridization experiments revealed that the deficient lines were defective in homologous pairing and cohesion at sister chromatid arms. These defects resulted in unequal chromosome segregation and aberrant spore generation. These observations suggest that OsRad21-4 is essential for efficient meiosis.


Assuntos
Proteínas Cromossômicas não Histona , Meiose/fisiologia , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Saccharomyces cerevisiae , Sequência de Aminoácidos , Sobrevivência Celular , Cromátides/genética , Cromossomos de Plantas/genética , Clonagem Molecular , DNA Complementar/genética , Éxons/genética , Flores/citologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Dados de Sequência Molecular , Oryza/genética , Filogenia , Infertilidade das Plantas , Proteínas de Plantas/genética , Pólen/metabolismo , Interferência de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Recombinantes de Fusão/metabolismo
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