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1.
Biomedicines ; 9(4)2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33805052

RESUMO

Cystic fibrosis (CF) is caused by mutations in the gene encoding the CF Transmembrane Conductance Regulator (CFTR), an apical chloride channel. An early inflammation (EI) in the lung of CF patients occurring in the absence of any bacterial infection has been reported. This EI has been proposed to be associated with oxidative stress (OX-S), generated by deregulations of the oxidant/antioxidant status. Recently, we demonstrated that copper (Cu), an essential trace element, mediates OX-S in bronchial cells. However, the role of this element in the development of CF-EI, in association with OX-S, has never been investigated. Using healthy (16HBE14o-; HBE), CF (CFBE14o-; CFBE), and corrected-wild type CFTR CF (CFBE-wt) bronchial cells, we characterized the inflammation and OX-S profiles in relation to the copper status and CFTR expression and function. We demonstrated that CFBE cells exhibited a CFTR-independent intrinsic inflammation. These cells also exhibited an alteration in mitochondria, UPR (Unfolded Protein Response), catalase, Cu/Zn- and Mn-SOD activities, and an increase in the intracellular content of iron, zinc, and Cu. The increase in Cu concentration was associated with OX-S and inflammatory responses. These data identify cellular Cu as a key factor in the generation of CF-associated OX-S and opens new areas of investigation to better understand CF-associated EI.

2.
Lancet ; 396(10260): 1422-1431, 2020 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-33002431

RESUMO

BACKGROUND: It is unclear whether adjuvant or early salvage radiotherapy following radical prostatectomy is more appropriate for men who present with localised or locally advanced prostate cancer. We aimed to prospectively plan a systematic review of randomised controlled trials (RCTs) comparing these radiotherapy approaches. METHODS: We used a prospective framework for adaptive meta-analysis (FAME), starting the review process while eligible trials were ongoing. RCTs were eligible if they aimed to compare immediate adjuvant radiotherapy versus early salvage radiotherapy, following radical prostatectomy in men (age ≥18 years) with intermediate-risk or high-risk, localised or locally advanced prostate cancer. We searched trial registers and conference proceedings until July 8, 2020, to identify eligible RCTs. By establishing the ARTISTIC collaboration with relevant trialists, we were able to anticipate when eligible trial results would emerge, and we developed and registered a protocol with PROSPERO before knowledge of the trial results (CRD42019132669). We used a harmonised definition of event-free survival, as the time from randomisation until the first evidence of either biochemical progression (prostate-specific antigen [PSA] ≥0·4 ng/mL and rising after completion of any postoperative radiotherapy), clinical or radiological progression, initiation of a non-trial treatment, death from prostate cancer, or a PSA level of at least 2·0 ng/mL at any time after randomisation. We predicted when we would have sufficient power to assess whether adjuvant radiotherapy was superior to early salvage radiotherapy. Investigators supplied results for event-free survival, both overall and within predefined patient subgroups. Hazard ratios (HRs) for the effects of radiotherapy timing on event-free survival and subgroup interactions were combined using fixed-effect meta-analysis. FINDINGS: We identified three eligible trials and were able to obtain updated results for event-free survival for 2153 patients recruited between November, 2007, and December, 2016. Median follow-up ranged from 60 months to 78 months, with a maximum follow-up of 132 months. 1075 patients were randomly assigned to receive adjuvant radiotherapy and 1078 to a policy of early salvage radiotherapy, of whom 421 (39·1%) had commenced treatment at the time of analysis. Patient characteristics were balanced within trials and overall. Median age was similar between trials at 64 or 65 years (with IQRs ranging from 59 to 68 years) across the three trials and most patients (1671 [77·6%]) had a Gleason score of 7. All trials were assessed as having low risk of bias. Based on 270 events, the meta-analysis showed no evidence that event-free survival was improved with adjuvant radiotherapy compared with early salvage radiotherapy (HR 0·95, 95% CI 0·75-1·21; p=0·70), with only a 1 percentage point (95% CI -2 to 3) change in 5-year event-free survival (89% vs 88%). Results were consistent across trials (heterogeneity p=0·18; I2=42%). INTERPRETATION: This collaborative and prospectively designed systematic review and meta-analysis suggests that adjuvant radiotherapy does not improve event-free survival in men with localised or locally advanced prostate cancer. Until data on long-term outcomes are available, early salvage treatment would seem the preferable treatment policy as it offers the opportunity to spare many men radiotherapy and its associated side-effects. FUNDING: UK Medical Research Council.


Assuntos
Prostatectomia , Neoplasias da Próstata/radioterapia , Neoplasias da Próstata/cirurgia , Biomarcadores Tumorais/sangue , Intervalo Livre de Doença , Humanos , Masculino , Gradação de Tumores , Estudos Prospectivos , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/patologia , Radioterapia Adjuvante , Ensaios Clínicos Controlados Aleatórios como Assunto , Terapia de Salvação
3.
Lancet Oncol ; 21(10): 1341-1352, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33002438

RESUMO

BACKGROUND: Adjuvant radiotherapy reduces the risk of biochemical progression in prostate cancer patients after radical prostatectomy. We aimed to compare adjuvant versus early salvage radiotherapy after radical prostatectomy, combined with short-term hormonal therapy, in terms of oncological outcomes and tolerance. METHODS: GETUG-AFU 17 was a randomised, open-label, multicentre, phase 3 trial done at 46 French hospitals. Men aged at least 18 years who had an Eastern Cooperative Oncology Group performance status of 1 or less, localised adenocarcinoma of the prostate treated with radical prostatectomy, who had pathologically-staged pT3a, pT3b, or pT4a (with bladder neck invasion), pNx (without pelvic lymph nodes dissection), or pN0 (with negative lymph nodes dissection) disease, and who had positive surgical margins were eligible for inclusion in the study. Eligible patients were randomly assigned (1:1) to either immediate adjuvant radiotherapy or delayed salvage radiotherapy at the time of biochemical relapse. Random assignment, by minimisation, was done using web-based software and stratified by Gleason score, pT stage, and centre. All patients received 6 months of triptorelin (intramuscular injection every 3 months). The primary endpoint was event-free survival. Efficacy and safety analyses were done on the intention-to-treat population. The trial is registered with ClinicalTrials.gov, NCT00667069. FINDINGS: Between March 7, 2008, and June 23, 2016, 424 patients were enrolled. We planned to enrol 718 patients, with 359 in each study group. However, on May 20, 2016, the independent data monitoring committee recommended early termination of enrolment because of unexpectedly low event rates. At database lock on Dec 19, 2019, the overall median follow-up time from random assignment was 75 months (IQR 50-100), 74 months (47-100) in the adjuvant radiotherapy group and 78 months (52-101) in the salvage radiotherapy group. In the salvage radiotherapy group, 115 (54%) of 212 patients initiated study treatment after biochemical relapse. 205 (97%) of 212 patients started treatment in the adjuvant group. 5-year event-free survival was 92% (95% CI 86-95) in the adjuvant radiotherapy group and 90% (85-94) in the salvage radiotherapy group (HR 0·81, 95% CI 0·48-1·36; log-rank p=0·42). Acute grade 3 or worse toxic effects occurred in six (3%) of 212 patients in the adjuvant radiotherapy group and in four (2%) of 212 patients in the salvage radiotherapy group. Late grade 2 or worse genitourinary toxicities were reported in 125 (59%) of 212 patients in the adjuvant radiotherapy group and 46 (22%) of 212 patients in the salvage radiotherapy group. Late genitourinary adverse events of grade 2 or worse were reported in 58 (27%) of 212 patients in the adjuvant radiotherapy group versus 14 (7%) of 212 patients in the salvage radiotherapy group (p<0·0001). Late erectile dysfunction was grade 2 or worse in 60 (28%) of 212 in the adjuvant radiotherapy group and 17 (8%) of 212 in the salvage radiotherapy group (p<0·0001). INTERPRETATION: Although our analysis lacked statistical power, we found no benefit for event-free survival in patients assigned to adjuvant radiotherapy compared with patients assigned to salvage radiotherapy. Adjuvant radiotherapy increased the risk of genitourinary toxicity and erectile dysfunction. A policy of early salvage radiotherapy could spare men from overtreatment with radiotherapy and the associated adverse events. FUNDING: French Health Ministry and Ipsen.


Assuntos
Adenocarcinoma/radioterapia , Antagonistas de Androgênios/administração & dosagem , Prostatectomia , Neoplasias da Próstata/radioterapia , Terapia de Salvação , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Idoso , Progressão da Doença , França , Humanos , Masculino , Doenças Urogenitais Masculinas/epidemiologia , Doenças Urogenitais Masculinas/etiologia , Uso Excessivo dos Serviços de Saúde/prevenção & controle , Pessoa de Meia-Idade , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Neoplasias da Próstata/cirurgia , Radioterapia Adjuvante/efeitos adversos , Terapia de Salvação/efeitos adversos , Análise de Sobrevida , Resultado do Tratamento
4.
Proc Natl Acad Sci U S A ; 117(5): 2704-2709, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-31941711

RESUMO

Nitrous oxide (N2O), a potent greenhouse gas in the atmosphere, is produced mostly from aquatic ecosystems, to which algae substantially contribute. However, mechanisms of N2O production by photosynthetic organisms are poorly described. Here we show that the green microalga Chlamydomonas reinhardtii reduces NO into N2O using the photosynthetic electron transport. Through the study of C. reinhardtii mutants deficient in flavodiiron proteins (FLVs) or in a cytochrome p450 (CYP55), we show that FLVs contribute to NO reduction in the light, while CYP55 operates in the dark. Both pathways are active when NO is produced in vivo during the reduction of nitrites and participate in NO homeostasis. Furthermore, NO reduction by both pathways is restricted to chlorophytes, organisms particularly abundant in ocean N2O-producing hot spots. Our results provide a mechanistic understanding of N2O production in eukaryotic phototrophs and represent an important step toward a comprehensive assessment of greenhouse gas emission by aquatic ecosystems.


Assuntos
Chlamydomonas reinhardtii/metabolismo , Óxido Nítrico/metabolismo , Óxido Nitroso/metabolismo , Chlamydomonas reinhardtii/genética , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Fotossíntese , Processos Fototróficos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
5.
BJU Int ; 125(6): 810-816, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-30946523

RESUMO

OBJECTIVES: To report the long-term oncological outcomes of a randomised trial comparing androgen-deprivation therapy (ADT) combined with external beam radiation therapy (EBRT) and ADT alone in patients with locally advanced prostate cancer. PATIENTS AND METHODS: In this multicentre phase III trial, patients were randomly assigned to ADT alone or ADT+EBRT. Leuprorelin 11.25 mg was administered for 3 years. The whole pelvis was treated at a dose of 46 Gy and the prostate with a boost from 20 to 28 Gy. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), disease-specific survival (DSS), locoregional PFS (LRPFS), metastasis-free survival (MFS), biochemical PFS (BPFS), and tolerance. RESULTS: With a median follow-up of 7.3 years, 263 patients were included. The 8-year PFS rate was significantly higher in the ADT+EBRT arm than in the ADT arm (48% vs 7%; hazard ratio [HR] 0.27, 95% confidence interval [CI] 0.17-0.39; P < 0.001); in patients with a baseline PSA level ≥50 ng/mL (HR 0.10, 95% CI 0.05-0.20; P < 0.001) and in patients with a baseline PSA level <50 ng/mL (HR 0.28, 95% CI 0.19-0.40; P < 0.001). The risk of death from prostate cancer was significantly reduced in the ADT+EBRT arm (sub-HR [SHR] 0.48, 95% CI 0.25-0.91; P = 0.02). The 8-year OS rate was 57% in the ADT arm and 65% in the ADT+EBRT arm (no significant difference). LRPFS was significantly in favour of the ADT+EBRT arm (SHR 0.61, 95% CI 0.42-0.89; P = 0.01). MFS was comparable between both arms (P = 0.88). Analysis of toxicities revealed acute lower tolerance in the ADT+EBRT arm, with a gradual decrease in intensity from 6 months after the end of EBRT. CONCLUSIONS: These long-term results confirm the oncological benefit of combining EBRT with ADT in the treatment of locally advanced prostate cancer.


Assuntos
Antagonistas de Androgênios/uso terapêutico , Neoplasias da Próstata , Radioterapia , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/patologia , Neoplasias da Próstata/radioterapia
6.
Plant J ; 99(5): 937-949, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31034704

RESUMO

Low-phosphate (Pi) conditions are known to repress primary root growth of Arabidopsis at low pH and in an Fe-dependent manner. This growth arrest requires accumulation of the transcription factor STOP1 in the nucleus, where it activates the transcription of the malate transporter gene ALMT1; exuded malate is suspected to interact with extracellular Fe to inhibit root growth. In addition, ALS3 - an ABC-like transporter identified for its role in tolerance to toxic Al - represses nuclear accumulation of STOP1 and the expression of ALMT1. Until now it was unclear whether Pi deficiency itself or Fe activates the accumulation of STOP1 in the nucleus. Here, by using different growth media to dissociate the effects of Fe from Pi deficiency itself, we demonstrate that Fe is sufficient to trigger the accumulation of STOP1 in the nucleus, which, in turn, activates the expression of ALMT1. We also show that a low pH is necessary to stimulate the Fe-dependent accumulation of nuclear STOP1. Furthermore, pharmacological experiments indicate that Fe inhibits proteasomal degradation of STOP1. We also show that Al acts like Fe for nuclear accumulation of STOP1 and ALMT1 expression, and that the overaccumulation of STOP1 in the nucleus of the als3 mutant grown in low-Pi conditions could be abolished by Fe deficiency. Altogether, our results indicate that, under low-Pi conditions, Fe2/3+ and Al3+ act similarly to increase the stability of STOP1 and its accumulation in the nucleus where it activates the expression of ALMT1.


Assuntos
Alumínio/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Núcleo Celular/metabolismo , Ferro/metabolismo , Fosfatos/metabolismo , Fatores de Transcrição/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Regulação da Expressão Gênica de Plantas , Malatos , Transportadores de Ânions Orgânicos/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Fatores de Transcrição/genética
7.
Antioxid Redox Signal ; 31(1): 59-74, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30569742

RESUMO

Aim: Bronchial epithelium acts as a defensive barrier against inhaled pollutants and microorganisms. This barrier is often compromised in inflammatory airway diseases that are characterized by excessive oxidative stress responses, leading to bronchial epithelial shedding, barrier failure, and increased bronchial epithelium permeability. Among proteins expressed in the junctional barrier and participating to the regulation of the response to oxidative and to environmental stresses is the cellular prion protein (PrPC). However, the role of PrPC is still unknown in the bronchial epithelium. Herein, we investigated the cellular mechanisms by which PrPC protein participates into the junctional complexes formation, regulation, and oxidative protection in human bronchial epithelium. Results: Both PrPC messenger RNA and mature protein were expressed in human epithelial bronchial cells. PrPC was localized in the apical domain and became lateral, at high degree of cell polarization, where it colocalized and interacted with adherens (E-cadherin/γ-catenin) and desmosomal (desmoglein/desmoplakin) junctional proteins. No interaction was detected with tight junction proteins. Disruption of such interactions induced the loss of the epithelial barrier. Moreover, we demonstrated that PrPC protection against copper-associated oxidative stress was involved in multiple processes, including the stability of adherens and desmosomal junctional proteins. Innovation: PrPC is a pivotal protein in the protection against oxidative stress that is associated with the degradation of adherens and desmosomal junctional proteins. Conclusion: Altogether, these results demonstrate that the loss of the integrity of the epithelial barrier by oxidative stress is attenuated by the activation of PrPC expression, where deregulation might be associated with respiratory diseases.


Assuntos
Brônquios/citologia , Sulfato de Cobre/efeitos adversos , Proteínas Priônicas/genética , Proteínas Priônicas/metabolismo , Células A549 , Junções Aderentes/metabolismo , Brônquios/metabolismo , Linhagem Celular , Polaridade Celular , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Humanos , Estresse Oxidativo
8.
Stat Methods Med Res ; 27(4): 1271-1281, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-27587597

RESUMO

Background Biomarker series can indicate disease progression and predict clinical endpoints. When a treatment is prescribed depending on the biomarker, confounding by indication might be introduced if the treatment modifies the marker profile and risk of failure. Objective Our aim was to highlight the flexibility of a two-stage model fitted within a Bayesian Markov Chain Monte Carlo framework. For this purpose, we monitored the prostate-specific antigens in prostate cancer patients treated with external beam radiation therapy. In the presence of rising prostate-specific antigens after external beam radiation therapy, salvage hormone therapy can be prescribed to reduce both the prostate-specific antigens concentration and the risk of clinical failure, an illustration of confounding by indication. We focused on the assessment of the prognostic value of hormone therapy and prostate-specific antigens trajectory on the risk of failure. Methods We used a two-stage model within a Bayesian framework to assess the role of the prostate-specific antigens profile on clinical failure while accounting for a secondary treatment prescribed by indication. We modeled prostate-specific antigens using a hierarchical piecewise linear trajectory with a random changepoint. Residual prostate-specific antigens variability was expressed as a function of prostate-specific antigens concentration. Covariates in the survival model included hormone therapy, baseline characteristics, and individual predictions of the prostate-specific antigens nadir and timing and prostate-specific antigens slopes before and after the nadir as provided by the longitudinal process. Results We showed positive associations between an increased prostate-specific antigens nadir, an earlier changepoint and a steeper post-nadir slope with an increased risk of failure. Importantly, we highlighted a significant benefit of hormone therapy, an effect that was not observed when the prostate-specific antigens trajectory was not accounted for in the survival model. Conclusion Our modeling strategy was particularly flexible and accounted for multiple complex features of longitudinal and survival data, including the presence of a random changepoint and a time-dependent covariate.


Assuntos
Teorema de Bayes , Análise de Sobrevida , Idoso , Pesquisa Biomédica/estatística & dados numéricos , Progressão da Doença , Hormônios/uso terapêutico , Humanos , Masculino , Probabilidade , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/tratamento farmacológico , Falha de Tratamento
9.
Biochim Biophys Acta Bioenerg ; 1859(2): 69-77, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28842179

RESUMO

The role of accessory Fe-S clusters of the F-domain in the catalytic activity of M3-type [FeFe] hydrogenase and the contribution of each of the two Fe-S surface clusters in the intermolecular electron transfer from ferredoxin are both poorly understood. We designed, constructed, produced and spectroscopically, electrochemically and biochemically characterized three mutants of Clostridium acetobutylicum CaHydA hydrogenase with modified Fe-S clusters: two site-directed mutants, HydA_C100A and HydA_C48A missing the FS4C and the FS2 surface Fe-S clusters, respectively, and a HydA_ΔDA mutant that completely lacks the F-domain. Analysis of the mutant enzyme activities clearly demonstrated the importance of accessory clusters in retaining full enzyme activity at potentials around and higher than the equilibrium 2H+/H2 potential but not at the lowest potentials, where all enzymes have a similar turnover rate. Moreover, our results, combined with molecular modelling approaches, indicated that the FS2 cluster is the main gate for electron transfer from reduced ferredoxin.


Assuntos
Clostridium acetobutylicum/enzimologia , Hidrogenase/química , Substituição de Aminoácidos , Proteínas de Bactérias , Clostridium acetobutylicum/genética , Hidrogenase/genética , Mutação de Sentido Incorreto , Domínios Proteicos
10.
Sci Rep ; 7(1): 17132, 2017 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-29214991

RESUMO

Metal uptake is vital for all living organisms. In metal scarce conditions a common bacterial strategy consists in the biosynthesis of metallophores, their export in the extracellular medium and the recovery of a metal-metallophore complex through dedicated membrane transporters. Staphylopine is a recently described metallophore distantly related to plant nicotianamine that contributes to the broad-spectrum metal uptake capabilities of Staphylococcus aureus. Here we characterize a four-gene operon (PA4837-PA4834) in Pseudomonas aeruginosa involved in the biosynthesis and trafficking of a staphylopine-like metallophore named pseudopaline. Pseudopaline differs from staphylopine with regard to the stereochemistry of its histidine moiety associated with an alpha ketoglutarate moiety instead of pyruvate. In vivo, the pseudopaline operon is regulated by zinc through the Zur repressor. The pseudopaline system is involved in nickel uptake in poor media, and, most importantly, in zinc uptake in metal scarce conditions mimicking a chelating environment, thus reconciling the regulation of the cnt operon by zinc with its function as the main zinc importer under these metal scarce conditions.


Assuntos
Proteínas de Bactérias/metabolismo , Quelantes/metabolismo , Oligopeptídeos/metabolismo , Óperon , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/metabolismo , Zinco/metabolismo , Proteínas de Bactérias/genética , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/crescimento & desenvolvimento
11.
Science ; 357(6354): 903-907, 2017 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28860382

RESUMO

Although many organisms capture or respond to sunlight, few enzymes are known to be driven by light. Among these are DNA photolyases and the photosynthetic reaction centers. Here, we show that the microalga Chlorella variabilis NC64A harbors a photoenzyme that acts in lipid metabolism. This enzyme belongs to an algae-specific clade of the glucose-methanol-choline oxidoreductase family and catalyzes the decarboxylation of free fatty acids to n-alkanes or -alkenes in response to blue light. Crystal structure of the protein reveals a fatty acid-binding site in a hydrophobic tunnel leading to the light-capturing flavin adenine dinucleotide (FAD) cofactor. The decarboxylation is initiated through electron abstraction from the fatty acid by the photoexcited FAD with a quantum yield >80%. This photoenzyme, which we name fatty acid photodecarboxylase, may be useful in light-driven, bio-based production of hydrocarbons.


Assuntos
Alcanos/metabolismo , Alcenos/metabolismo , Biocatálise , Carboxiliases/metabolismo , Chlorella/enzimologia , Ácidos Graxos/metabolismo , Oxirredutases/metabolismo , Proteínas de Plantas/metabolismo , Carboxiliases/química , Carboxiliases/classificação , Carboxiliases/efeitos da radiação , Flavina-Adenina Dinucleotídeo/metabolismo , Luz , Metabolismo dos Lipídeos , Oxirredutases/química , Oxirredutases/classificação , Oxirredutases/efeitos da radiação , Processos Fotoquímicos , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/classificação , Proteínas de Plantas/efeitos da radiação
12.
Plant Physiol ; 174(3): 1825-1836, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28487478

RESUMO

During oxygenic photosynthesis, the reducing power generated by light energy conversion is mainly used to reduce carbon dioxide. In bacteria and archae, flavodiiron (Flv) proteins catalyze O2 or NO reduction, thus protecting cells against oxidative or nitrosative stress. These proteins are found in cyanobacteria, mosses, and microalgae, but have been lost in angiosperms. Here, we used chlorophyll fluorescence and oxygen exchange measurement using [18O]-labeled O2 and a membrane inlet mass spectrometer to characterize Chlamydomonas reinhardtii flvB insertion mutants devoid of both FlvB and FlvA proteins. We show that Flv proteins are involved in a photo-dependent electron flow to oxygen, which drives most of the photosynthetic electron flow during the induction of photosynthesis. As a consequence, the chlorophyll fluorescence patterns are strongly affected in flvB mutants during a light transient, showing a lower PSII operating yield and a slower nonphotochemical quenching induction. Photoautotrophic growth of flvB mutants was indistinguishable from the wild type under constant light, but severely impaired under fluctuating light due to PSI photo damage. Remarkably, net photosynthesis of flv mutants was higher than in the wild type during the initial hour of a fluctuating light regime, but this advantage vanished under long-term exposure, and turned into PSI photo damage, thus explaining the marked growth retardation observed in these conditions. We conclude that the C. reinhardtii Flv participates in a Mehler-like reduction of O2, which drives a large part of the photosynthetic electron flow during a light transient and is thus critical for growth under fluctuating light regimes.


Assuntos
Chlamydomonas/metabolismo , Chlamydomonas/efeitos da radiação , Flavoproteínas/metabolismo , Luz , Oxigênio/metabolismo , Chlamydomonas/genética , Chlamydomonas/crescimento & desenvolvimento , Clorofila/metabolismo , Transporte de Elétrons , Fluorescência , Espectrometria de Massas , Mutação/genética , Oxirredução , Paraquat/farmacologia , Fotossíntese/efeitos da radiação , Complexo de Proteína do Fotossistema I/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo
13.
PLoS One ; 12(4): e0174978, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28384195

RESUMO

OBJECTIVES: Radical cystectomy (RC) and pelvic lymph-node dissection (LND) is standard treatment for non-metastatic muscle-invasive urothelial bladder cancer (MIBC). However, loco-regional recurrence (LRR) is a common early event associated with poor prognosis. We evaluate 3-year LRR-free (LRRFS), metastasis-free (MFS) and overall survivals (OS) after adjuvant radiotherapy (RT) for pathological high-risk MIBC. MATERIAL AND METHODS: We retrospectively reviewed data from patients in 3 institutions. Inclusion criteria were MIBC, histologically-proven urothelial carcinoma treated by RC and adjuvant RT. Patients with conservative surgery were excluded. Outcomes were evaluated by Kaplan-Meier method. Acute toxicities were recorded according to CTCAE V4.0 scale. RESULTS: Between 2000 and 2013, 57 patients [median age 66.3 years (45-84)] were included. Post-operative pathological staging was ≤pT2, pT3 and pT4 in 16%, 44%, and 39%, respectively. PLND revealed 28% pN0, 26% pN1 and 42% pN2. Median number of lymph-nodes retrieved was 10 (2-33). Forty-eight patients (84%) received platin-based chemotherapy. For RT, clinical target volume 1 (CTV 1) encompassed pelvic lymph nodes for all patients. CTV 1 also included cystectomy bed for 37 patients (65%). CTV 1 median dose was 45 Gy (4-50). A boost of 16 Gy (5-22), corresponding to CTV 2, was administered for 30 patients, depending on pathological features. One third of patients received intensity-modulated RT. With median follow-up of 40.4 months, 8 patients (14%) had LRR. Three-year LRRFS, MFS and OS were 45% (95%CI 30-60), 37% (95%CI 24-51) and 49% (95%CI 33-63), respectively. Five (9%) patients had acute grade ≥3 toxicities (gastro-intestinal, genito-urinary and biological parameters). One patient died with intestinal fistula in a septic context. CONCLUSIONS: Because of poor prognosis, an effective post-operative standard of care is needed for pathological high-risk MIBC. Adjuvant RT is feasible and may have oncological benefits. Prospective trials evaluating this approach with current RT techniques should be undertaken.


Assuntos
Cistectomia/métodos , Músculos/patologia , Neoplasias da Bexiga Urinária/radioterapia , Neoplasias da Bexiga Urinária/cirurgia , Idoso , Idoso de 80 Anos ou mais , Terapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Estudos Retrospectivos , Análise de Sobrevida , Neoplasias da Bexiga Urinária/patologia
14.
Low Urin Tract Symptoms ; 9(2): 82-88, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28394498

RESUMO

OBJECTIVE: In patients with prostate cancer (PCa), prostate enlargement may give rise to lower urinary tract symptoms (LUTS); many patients suffer from moderate-to-severe symptoms. We compare the efficacy of degarelix and goserelin plus bicalutamide in improving LUTS in PCa patients. METHODS: Data were pooled from three Phase 3, randomized clinical trials of once-monthly treatment for 12 weeks with degarelix (240/80 mg; n = 289) or goserelin (3.6 mg) plus bicalutamide (50 mg; n = 174) for initial flare protection. LUTS at weeks 4, 8, and 12 were compared to baseline. Clinically relevant LUTS relief was a ≥3-point International Prostate Symptom Score (IPSS) decrease. Adverse events were assessed throughout the trials. RESULTS: Patients receiving degarelix had significantly greater decreases in IPSS vs. goserelin at week 12 (adjusted difference: -1.24; 95% CI -2.33 to -0.14, P = 0.03). Clinically relevant LUTS relief with degarelix was especially pronounced in patients with moderate-to-severe LUTS (baseline IPSS ≥13) (odds ratio; OR 2.31; 95% CI 1.19-4.47, P = 0.01) and advanced PCa (OR 2.36; 95% CI 1.10-5.04, P = 0.03). A twofold higher OR for early (week 4) LUTS relief was seen with degarelix vs. goserelin (OR 2.03; 95% CI 1.14-3.60, P = 0.02). No difference in total prostate volume or urinary tract infection-related adverse events (2%) was seen between treatment groups. CONCLUSION: An early, significant and clinically more pronounced improvement of LUTS, especially in patients with moderate-to-severe LUTS or advanced PCa, was seen with degarelix vs. goserelin plus bicalutamide.


Assuntos
Antagonistas de Androgênios/administração & dosagem , Anilidas/administração & dosagem , Antineoplásicos Hormonais/administração & dosagem , Gosserrelina/administração & dosagem , Sintomas do Trato Urinário Inferior/tratamento farmacológico , Nitrilas/administração & dosagem , Oligopeptídeos/administração & dosagem , Compostos de Tosil/administração & dosagem , Idoso , Análise de Variância , Esquema de Medicação , Humanos , Sintomas do Trato Urinário Inferior/etiologia , Sintomas do Trato Urinário Inferior/patologia , Masculino , Tamanho do Órgão , Próstata/patologia , Antígeno Prostático Específico/metabolismo , Neoplasias da Próstata/complicações , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Testosterona/metabolismo , Resultado do Tratamento
15.
Front Oncol ; 7: 34, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28337425

RESUMO

In the era of intensity-modulated radiation therapy, image-guided radiotherapy (IGRT) appears crucial to control dose delivery and to promote dose escalation while allowing healthy tissue sparing. The place of IGRT following radical prostatectomy is poorly described in the literature. This review aims to highlight some key points on the different IGRT techniques applicable to prostatic bed radiotherapy. Furthermore, methods used to evaluate target motion and to reduce planning target volume margins will also be explored.

16.
Bladder Cancer ; 3(1): 19-30, 2017 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-28149931

RESUMO

Local-regional recurrence for patients with ≥pT3 disease after radical cystectomy is a significant problem. Chemotherapy has not been shown to reduce the risk of local-regional recurrences in randomized prospective trials, and salvage therapies for local-regional failure are rarely successful. There is promising evidence, particularly from a recent Egyptian NCI trial, that radiation therapy plus chemotherapy can significantly reduce local recurrences compared to chemotherapy alone, and that this improvement in local-regional control may translate to meaningful improvements in disease-free and overall survival with acceptable toxicity. In light of the high rates of local failure following cystectomy for locally advanced disease and the progress that has been made in identifying patients at high risk of failure and the patterns of failure in the pelvis, the NCCN guidelines were revised in 2016 to include post-operative radiotherapy as an option to consider for patients with ≥pT3 disease. Despite advances in our understanding of the problem of local-regional failure after cystectomy and the potential role of adjuvant radiotherapy, the question of whether adjuvant radiotherapy should have a defined role for patients with locally advanced urothelial carcinoma has not yet been determined. The results of the NRG, European, Indian, and Egyptian trials on adjuvant radiotherapy are eagerly awaited. While none of these trials on their own may provide definitive conclusions, their aggregate outcomes will help clarify whether this treatment should have a role in the management of patients with locally advanced bladder cancer.

17.
Cancer Treat Rev ; 55: 211-217, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27665366

RESUMO

Data from the literature support with strong evidence the addition of docetaxel to androgen-deprivation therapy (ADT) for men with metastatic prostate cancer, and starting therapy for the first time. A meta-analysis of three randomized controlled trials showed a significant improvement of overall survival when ADT was combined with docetaxel when compared to ADT alone (HR=0.77; 95% CI: 0.68-0.87; p<0.0001). Consequently, combination therapy should be considered presently as the new standard of care, using 6 cycles of docetaxel, without prednisone. However, candidates for this upfront combination therapy in whom the balance between its side effects and benefits is favorable are still to be identified more precisely. Patients' stratification according to Gleason score, previous local treatment and age or performance status were shown to have a prognostic impact. The volume of metastases, as defined in the CHAARTED study for instance, could be an interesting predictive factor. However, data accumulated until now remain only hypothesis generating and further analysis and studies are needed to establish any potential discriminating factors. Several new efficient therapeutic options are now available in prostate cancer management and should be evaluated against a chemo-hormonal combination therapy. Other trials are warranted to establish the role of docetaxel in earlier stages of the disease, the combination with the new hormonal therapies as well as the best management options after docetaxel.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Vigilância da População , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Fatores Etários , Antagonistas de Androgênios/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Progressão da Doença , Docetaxel , Medicina Baseada em Evidências , Nível de Saúde , Humanos , Masculino , Gradação de Tumores , Metástase Neoplásica , Seleção de Pacientes , Prednisona/administração & dosagem , Taxoides/administração & dosagem , Carga Tumoral , Incerteza
18.
PLoS Pathog ; 12(12): e1006018, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27923069

RESUMO

Metal acquisition is crucial for all cells and for the virulence of many bacterial pathogens. In particular, nickel is a virulence determinant for the human gastric pathogen Helicobacter pylori as it is the cofactor of two enzymes essential for in vivo colonization, urease and a [NiFe] hydrogenase. To import nickel despite its scarcity in the human body, H. pylori requires efficient uptake mechanisms that are only partially defined. Indeed, alternative ways of nickel entry were predicted to exist in addition to the well-described NixA permease. Using a genetic screen, we identified an ABC transporter, that we designated NiuBDE, as a novel H. pylori nickel transport system. Unmarked mutants carrying deletions of nixA, niuD and/or niuB, were constructed and used to measure (i) tolerance to toxic nickel exposure, (ii) intracellular nickel content by ICP-OES, (iii) transport of radioactive nickel and (iv) expression of a reporter gene controlled by nickel concentration. We demonstrated that NiuBDE and NixA function separately and are the sole nickel transporters in H. pylori. NiuBDE, but not NixA, also transports cobalt and bismuth, a metal currently used in H. pylori eradication therapy. Both NiuBDE and NixA participate in nickel-dependent urease activation at pH 5 and survival under acidic conditions mimicking those encountered in the stomach. However, only NiuBDE is able to carry out this activity at neutral pH and is essential for colonization of the mouse stomach. Phylogenomic analyses indicated that both nixA and niuBDE genes have been acquired via horizontal gene transfer by the last common ancestor of the gastric Helicobacter species. Our work highlights the importance of this evolutionary event for the emergence of Helicobacter gastric species that are adapted to the hostile environment of the stomach where the capacity of Helicobacter to import nickel and thereby activate urease needs to be optimized.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Proteínas de Bactérias/metabolismo , Helicobacter pylori/metabolismo , Níquel/metabolismo , Virulência/fisiologia , Transportadores de Cassetes de Ligação de ATP/genética , Animais , Proteínas de Bactérias/genética , Evolução Biológica , Transporte Biológico/fisiologia , Modelos Animais de Doenças , Infecções por Helicobacter/metabolismo , Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , Camundongos , Filogenia
19.
Transl Androl Urol ; 5(5): 702-710, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27785427

RESUMO

Radical cystectomy with extended pelvic lymph-node dissection, associated with neo-adjuvant chemotherapy, remains the standard of care for advanced, non-metastatic muscle-invasive bladder cancer (MIBC). Loco-regional control is a key factor in the outcome of patients since it is related to overall survival (OS), disease-free survival (DFS) and cause-specific survival. The risk of loco-regional recurrence (LRR) is correlated to pathological factors as well as the extent of the lymphadenectomy. In addition, neither pre- nor post-operative chemotherapy have shown a clear impact on LRR-free survival. Several recent publications have led to the development of a nomogram predicting the risk of LRR, in order to identify patients most likely to benefit from adjuvant radiotherapy. Given the high risk of LRR for selected patients and improvements in radiation techniques that can reduce toxicity, there is a growing interest in adjuvant radiotherapy; international cooperative groups have come together to provide the rationale in favor of adjuvant radiotherapy. Clinical trials in order to reduce the risk of pelvic relapse are opened based on this optimizing patient selection. The aim of this critical literature review is to provide an overview of the rationale supporting the studies of adjuvant radiation for patients with pathologic high-risk MIBC.

20.
Int J Radiat Oncol Biol Phys ; 96(4): 759-769, 2016 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-27788949

RESUMO

PURPOSE: To report the long-term results of the French Genitourinary Study Group (GETUG)-01 study in terms of event-free survival (EFS) and overall survival (OS) and assess the potential interaction between hormonotherapy and pelvic nodes irradiation. PATIENTS AND METHODS: Between December 1998 and June 2004, 446 patients with T1b-T3, N0pNx, M0 prostate carcinoma were randomly assigned to either pelvic nodes and prostate or prostate-only radiation therapy. Patients were stratified into 2 groups: "low risk" (T1-T2 and Gleason score 6 and prostate-specific antigen <3× the upper normal limit of the laboratory) (92 patients) versus "high risk" (T3 or Gleason score >6 or prostate-specific antigen >3× the upper normal limit of the laboratory). Short-term 6-month neoadjuvant and concomitant hormonal therapy was allowed only for high-risk patients. Radiation therapy was delivered with a 3-dimensional conformal technique, using a 4-field technique for the pelvic volume (46 Gy). The total dose recommended to the prostate moved from 66 Gy to 70 Gy during the course of the study. Criteria for EFS included biologic prostate-specific antigen recurrences and/or a local or metastatic progression. RESULTS: With a median follow-up of 11.4 years, the 10-year OS and EFS were similar in the 2 treatment arms. A higher but nonsignificant EFS was observed in the low-risk subgroup in favor of pelvic nodes radiation therapy (77.2% vs 62.5%; P=.18). A post hoc subgroup analysis showed a significant benefit of pelvic irradiation when the risk of lymph node involvement was <15% (Roach formula). This benefit seemed to be limited to patients who did not receive hormonal therapy. CONCLUSION: Pelvic nodes irradiation did not statistically improve EFS or OS in the whole population but may be beneficial in selected low- and intermediate-risk prostate cancer patients treated with exclusive radiation therapy.


Assuntos
Irradiação Linfática/métodos , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/radioterapia , Idoso , Antineoplásicos Hormonais/uso terapêutico , Intervalo Livre de Doença , Fracionamento da Dose de Radiação , Seguimentos , França , Hormônio Liberador de Gonadotropina/agonistas , Humanos , Irradiação Linfática/mortalidade , Masculino , Gradação de Tumores , Recidiva Local de Neoplasia/sangue , Estadiamento de Neoplasias , Pelve , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Radioterapia Conformacional/métodos , Fatores de Tempo
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