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1.
Clin Exp Metastasis ; 35(8): 777-783, 2018 12.
Article de Anglais | MEDLINE | ID: mdl-30324492

RÉSUMÉ

Optimization of axillary staging among patients converting from clinically node-positive disease to clinically node-negative disease through primary systemic therapy is needed. We aimed at developing a nomogram predicting the probability of positive axillary status after chemotherapy based on clinical/pathological parameters. Patients from study arm C of the SENTINA trial were included. Univariable/multivariable analyses were performed for 13 clinical/pathological parameters to predict a positive pathological axillary status after chemotherapy using logistic regression models. Odds ratios and 95%-confidence-intervals were reported. Model performance was assessed by leave-one-out cross-validation. Calculations were performed using the SAS Software (Version 9.4, SAS Institute Inc., Cary, NC, USA). 369 of 553 patients in Arm C were included in multivariable analysis. Stepwise backward variable selection based on a multivariable analysis resulted in a model including estrogen receptor (ER) status (odds ratio (OR) 3.916, 95% confidence interval (CI) 2.318-6.615, p < 0.001), multifocality (OR 2.106, 95% CI 1.203-3.689, p = 0.0092), lymphovascular invasion (OR 9.196, 95% CI 4.734-17.864, p < 0.001), and sonographic tumor diameter after PST (OR 1.034, 95% CI 1.010-1.059, p = 0.0051). When validated, our model demonstrated an accuracy of 70.2% using 0.5 as cut-point. An area under the curve of 0.81 was calculated. The use of individual parameters as predictors of lymph node status after chemotherapy resulted in an inferior accuracy. Our model was able to predict the probability of a positive axillary nodal status with a high accuracy. The use of individual parameters showed reduced predictive performance. Overall, tumor biology was the strongest parameter in our models.


Sujet(s)
Tumeurs du sein/anatomopathologie , Métastase lymphatique/anatomopathologie , Stadification tumorale/méthodes , Nomogrammes , Adulte , Sujet âgé , Antinéoplasiques/usage thérapeutique , Aire sous la courbe , Aisselle , Tumeurs du sein/traitement médicamenteux , Traitement médicamenteux adjuvant , Femelle , Humains , Métastase lymphatique/diagnostic , Adulte d'âge moyen , Traitement néoadjuvant , Courbe ROC , Noeud lymphatique sentinelle/anatomopathologie , Biopsie de noeud lymphatique sentinelle
2.
Clin Respir J ; 12(3): 1106-1117, 2018 Mar.
Article de Anglais | MEDLINE | ID: mdl-28398662

RÉSUMÉ

OBJECTIVES: The influence of blood group antigens on cancerogenesis is shown for distinct tumor types, yet the impact of Rhesus blood group antigens in lung cancer is not clarified. MATERIALS AND METHODS: To investigate the impact of Rhesus blood groups a non-small cell lung cancer (NSCLC) collective (n = 1047) was analyzed retrospectively. Using a second cohort of n = 340 primarily operated stage I-III NSCLC patients, we evaluated immunohistochemistry of CD47-antibody stained tissue samples in correlation to histopathologic subtype and Rhesus blood group. RESULTS AND CONCLUSION: In 516 of 1047 patients blood group data were available. Seven different RhCE phenotypes were grouped as "··ee," "ccE·," and "C·E·." Adenocarcinoma patients with Rh "··ee" revealed improved overall survival (29 (21.2-36.8) m; HR 1.00 [index]) compared with Rh "ccE·" (19 (1.9-36.1) m; HR 1.76 [1.15-2.70]) and Rh "C·E·" (10 (7.4-12.6) m; HR 2.65 [1.70-4.12]) univariately (P < .001) and multivariately (P < .001). Rh "··ee" showed reduced incidence of CNS-metastasis (P = .014) and metastasis count (P = .032) in stage IV adenocarcinoma. Immunohistochemistry associated CD47-positivity with adenocarcinomas (n = 340, P = .048). In n = 51 cases blood group data were available. The prognostic effect of Rh "··ee" compared with Rh "ccE·" and Rh "C·E·" was stated (P = .001), foremost in CD47-positive adenocarcinomas (Rh "··ee" vs. Rh "ccE·" and Rh "C·E·," P = .008). Inversely Rh "ccE·" or Rh "C·E·" was found beneficial in CD47-negative non-adenocarcinomas (P = .046). Phenotypic RhCE expression may be an independent prognostic factor for overall survival in adeno-NSCLC. We hypothesize an erythrocytic-immunologic interaction with tumor tissue, possibly altered by RhCE and CD47, resulting in a metastatic prone condition.


Sujet(s)
Carcinome pulmonaire non à petites cellules/sang , Érythrocytes/métabolisme , Tumeurs du poumon/sang , Stadification tumorale , Système Rhésus/biosynthèse , Marqueurs biologiques tumoraux/biosynthèse , Marqueurs biologiques tumoraux/sang , Carcinome pulmonaire non à petites cellules/diagnostic , Carcinome pulmonaire non à petites cellules/mortalité , Évolution de la maladie , Femelle , Allemagne/épidémiologie , Humains , Immunohistochimie , Tumeurs du poumon/diagnostic , Tumeurs du poumon/mortalité , Mâle , Adulte d'âge moyen , Pronostic , Taux de survie/tendances
3.
J Crohns Colitis ; 11(9): 1052-1062, 2017 Sep 01.
Article de Anglais | MEDLINE | ID: mdl-28486634

RÉSUMÉ

BACKGROUND AND AIM: Recent observational studies document that non-adherence to mesalamine therapy during remission is frequent. We aimed to investigate patient impact of patient education using objective assessments of adherence. METHODS: A 14-month randomised, prospective clinical trial of adherence to mesalamine was conducted in 248 patients with ulcerative colitis [UC], Colitis Activity Index [CAI] ≤ 9, receiving standard care [n = 122] versus a standardised patient education programme [n = 126]. Primary endpoint was adherence at all visits (5-aminosalicylic acid [5-ASA] urine levels). Secondary endpoints included quality of life (inflammatory bowel disease questionnaise [IBDQ]), disease activity, partial adherence, and self-assessment of adherence. RESULTS: Patient allocation was well balanced. Baseline non-adherence was high in quiescent/mildly active UC [52.4%] without difference between the groups (52.4% of patients in the education group versus 52.5% in the standard care group [p = 0.99]). No difference between the intervention group and standard care was seen in IBDQ, partial adherence, self-assessment of adherence, or therapy satisfaction at all visits. We suggest a model in which individual risks for non-adherence are driven by patients with young age, short disease duration, and low education levels. CONCLUSIONS: Non-adherence is frequent in a population with quiescent/mildly active UC. Although more than 25% of the population was not in remission at the various time points, no relationship between disease activity and adherence was seen over the 14-month observation period. Physicians should maximise their efforts to motivate high-risk patients for adherence. Future trials should use objective exposure assessments to examine the impact of continuous education and consultations on the background of individual risks to develop non-adherence.


Sujet(s)
Anti-inflammatoires non stéroïdiens/usage thérapeutique , Rectocolite hémorragique/traitement médicamenteux , Adhésion au traitement médicamenteux/statistiques et données numériques , Mésalazine/usage thérapeutique , Éducation du patient comme sujet , Adolescent , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Rectocolite hémorragique/psychologie , Femelle , Études de suivi , Humains , Modèles logistiques , Mâle , Adhésion au traitement médicamenteux/psychologie , Adulte d'âge moyen , Études prospectives , Qualité de vie , Résultat thérapeutique , Jeune adulte
4.
Handchir Mikrochir Plast Chir ; 48(4): 212-8, 2016 Aug.
Article de Allemand | MEDLINE | ID: mdl-27547929

RÉSUMÉ

OBJECTIVE: Some patients with sacral scars, e. g. those developing after pilonidal sinus surgery, report discomfort when sitting or putting strain on the scars. In order to establish objective criteria for the assessment of this kind of discomfort and for the evaluation of scar quality after various types of surgical interventions, it is of interest to provide a method which enables physicians to assess skin quality in the sacral region. For this purpose, we developed a mechanical, non-invasive, fast and cost-neutral method for the measurement of skin distensibility and mobility. We examined a healthy sample of 100 study participants to establish benchmark values for scar-free skin in the sacral region and to identify the factors which impact skin quality, e. g. age, weight and sex. METHOD: With the participant in a standing position, 4 vertically arranged measurement points, which are exactly spaced in cranial to caudal direction by 10 mm-100 mm-10 mm, are marked in the lumbar and sacral region, respectively. The participant is then asked to bend forward and - with arms and legs fully stretched on both sides - to touch both their patellae with the balls of their hands so that the distance between the measurement points can be measured in this position as well. Then, with the participant standing upright again, another measurement is taken to establish the distance by which the lowest point can be manually moved in cranial direction. RESULTS: The sacral-lumbar skin distension quotient (lumbar skin distension / sacral skin distension×100), which can easily be calculated from the measurements, is independent of age and BMI and has a standard range of about 80-93%. Sacral skin mobility ranges from 11 to 18 mm, but is slightly negatively influenced by a high BMI. CONCLUSION: By comparing lumbar and sacral skin distension in the same study participant, we are able to obtain intraindividually valid findings about possible changes in skin and scar quality. Owing to the lack of known published data about sacral skin elasticity, the proposed measurement method, while restricted to a number of special cases, seems to be practicable and independent of the patient's general condition. Compared with devices that have been used for the measurement of elasticity in other skin areas, our procedure is generally available and cost-neutral.


Sujet(s)
Cicatrice , Sacrum , Procédures chirurgicales dermatologiques , Élasticité , Humains , Peau
5.
Bone Marrow Transplant ; 51(11): 1441-1448, 2016 Nov.
Article de Anglais | MEDLINE | ID: mdl-27295269

RÉSUMÉ

Allogeneic stem cell transplantation (SCT) remains the best curative option for patients with refractory AML or with high-risk myelodysplastic syndrome (MDS). For decades, age alone had been widely used as the primary criterion to assess eligibility for allogeneic SCT; however, prospective studies to evaluate allogeneic SCT in elderly patients are still limited. A total of 187 patients (median age of 64 years, range 60-77 years) with AML (87%) or MDS (13%) transplanted between 1999 and 2014 were included in this retrospective analysis. Relapse-free survival (RFS) and overall survival (OS) at 3 years were 32% (95% confidence interval (CI): 25-39%) and 35% (95%CI: 27-42%), respectively. Overall survival was 49% (95%CI: 35-64%) in AML patients who were transplanted in first complete remission (CR1), but even patients with active disease did benefit from transplantation, showing an OS at 3 years of 30% (95%CI: 20-40%). Multivariate analysis revealed disease- and patient-specific risk indices as independent prognostic factors for OS and non-relapse mortality (NRM). In conclusion, our monocenter results indicate that patients should not be generally withheld from allogeneic SCT because of age or disease status only. Specific risk models incorporating disease status and disease-specific risk factors at the time of transplantation as well as existing comorbidities are helpful tools to assess transplantation-associated risk factors of elderly patients.


Sujet(s)
Transplantation de cellules souches hématopoïétiques/méthodes , Leucémie aigüe myéloïde/thérapie , Syndromes myélodysplasiques/thérapie , Appréciation des risques/méthodes , Facteurs âges , Sujet âgé , Femelle , Transplantation de cellules souches hématopoïétiques/mortalité , Humains , Leucémie aigüe myéloïde/mortalité , Mâle , Adulte d'âge moyen , Syndromes myélodysplasiques/mortalité , Études rétrospectives , Analyse de survie , Transplantation homologue , Résultat thérapeutique
7.
Leukemia ; 30(6): 1230-6, 2016 06.
Article de Anglais | MEDLINE | ID: mdl-26859081

RÉSUMÉ

We randomized 3375 adults with newly diagnosed acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome to test whether increasingly intensive chemotherapies assigned at study-entry and analyzed on an intent-to-treat basis improved outcomes. In total, 1529 subjects <60 years were randomized to receive: (1) a first course of induction therapy with high-dose cytarabine and mitoxantrone (HAM) or with standard-dose cytarabine, daunorubicin and 6-thioguanine (TAD) followed by a second course of HAM; (2) granulocyte-colony stimulating factor (G-CSF) or no G-CSF before induction and consolidation courses; and (3) high-dose therapy and an autotransplant or maintenance chemotherapy. In total, 1846 subjects ⩾60 years were randomized to receive: (1) a first induction course of HAM or TAD and second induction course of HAM (if they had bone marrow blasts ⩾5% after the first course); and (2) G-CSF or no G-CSF as above. Median follow-up was 7.4 years (range, 1 day to 14.7 years). Five-year event-free survivals (EFSs) for subjects receiving a first induction course of HAM vs TAD were 17% (95% confidence interval, 15, 18%) vs 16% (95% confidence interval 14, 18%; P=0.719). Five-year EFSs for subjects randomized to receive or not receive G-CSF were 19% (95% confidence interval 16, 21%) vs 16% (95% confidence interval 14, 19%; P=0.266). Five-year relapse-free survivals (RFSs) for subjects <60 years receiving an autotransplant vs maintenance therapy were 43% (95% confidence interval 40, 47%) vs 40 (95% confidence interval 35, 44%; P=0.535). Many subjects never achieved pre-specified landmarks and consequently did not receive their assigned therapies. These data indicate the limited impact of more intensive therapies on outcomes of adults with AML. Moreover, none of the more intensive therapies we tested improved 5-year EFS, RFS or any other outcomes.


Sujet(s)
Leucémie aigüe myéloïde/traitement médicamenteux , Adulte , Aminoglutéthimide/usage thérapeutique , Protocoles de polychimiothérapie antinéoplasique/usage thérapeutique , Cytarabine/usage thérapeutique , Danazol/usage thérapeutique , Survie sans rechute , Facteur de stimulation des colonies de granulocytes , Humains , Chimiothérapie d'induction , Leucémie aigüe myéloïde/mortalité , Leucémie aigüe myéloïde/thérapie , Adulte d'âge moyen , Mitoxantrone/usage thérapeutique , Transplantation de cellules souches , Taux de survie , Tamoxifène/usage thérapeutique , Transplantation autologue , Résultat thérapeutique , Jeune adulte
8.
Lung Cancer ; 92: 8-14, 2016 Feb.
Article de Anglais | MEDLINE | ID: mdl-26775589

RÉSUMÉ

OBJECTIVES: Several blood group-related carbohydrate antigens are prognosis-relevant markers of tumor tissues. A type 3 (repetitive A) is a blood group antigen specific for A1 erythrocytes. Its potential expression in tumor tissues has so far not been examined. MATERIAL AND METHODS: We have evaluated its expression in normal lung and in lung cancer using a novel antibody (A69-A/E8). For comparison an anti-A antibody specific to A types 1 and 2 was used, because its expression on lung cancer tissue has been previously reported to be of prognostic relevance. Resected tissue samples of 398 NSCLC patients were analyzed in immunohistochemistry using tissue microarrays. RESULTS AND CONCLUSIONS: Expression of A type 3 was not observed in non-malignant lung tissues. A type 3 was expressed on tumor cells of around half of NSCLC patients of blood group A1 (p<0.001). Whereas no prognostic effect for A type 1/2 antigen was observed (p=0.562), the expression of A type 3 by tumor cells indicated a highly significant favorable prognosis among advanced NSCLC patients (p=0.011) and in NSCLC patients with lymphatic spread (p=0.014). Univariate prognostic results were confirmed in a Cox proportional hazards model. In this study we present for the first time prognostic data for A type 3 antigen expression in lung cancer patients. Prospective studies should be performed to confirm the prognostic value of A type 3 expression for an improved risk stratification in NSCLC patients.


Sujet(s)
Antigènes néoplasiques/sang , Marqueurs biologiques tumoraux/sang , Antigènes de groupe sanguin/sang , Carcinome pulmonaire non à petites cellules/sang , Tumeurs du poumon/sang , Sujet âgé , Antigènes de groupe sanguin/biosynthèse , Carcinome pulmonaire non à petites cellules/métabolisme , Carcinome pulmonaire non à petites cellules/anatomopathologie , Femelle , Humains , Immunohistochimie , Tumeurs du poumon/métabolisme , Tumeurs du poumon/anatomopathologie , Mâle , Pronostic , Analyse de survie , Analyse sur puce à tissus
9.
Leukemia ; 29(5): 1084-91, 2015 May.
Article de Anglais | MEDLINE | ID: mdl-25627637

RÉSUMÉ

In 2008, a European registry of relapsed acute promyelocytic leukemia was established by the European LeukemiaNet. Outcome data were available for 155 patients treated with arsenic trioxide in first relapse. In hematological relapse (n=104), 91% of the patients entered complete hematological remission (CR), 7% had induction death and 2% resistance, 27% developed differentiation syndrome and 39% leukocytosis, whereas no death or side effects occurred in patients treated in molecular relapse (n=40). The rate of molecular (m)CR was 74% in hematological and 62% in molecular relapse (P=0.3). All patients with extramedullary relapse (n=11) entered clinical and mCR. After 3.2 years median follow-up, the 3-year overall survival (OS) and cumulative incidence of second relapse were 68% and 41% in hematological relapse, 66% and 48% in molecular relapse and 90 and 11% in extramedullary relapse, respectively. After allogeneic or autologous transplantation in second CR (n=93), the 3-year OS was 80% compared with 59% without transplantation (n=55) (P=0.03). Multivariable analysis demonstrated the favorable prognostic impact of first remission duration ⩾1.5 years, achievement of mCR and allogeneic or autologous transplantation on OS of patients alive after induction (P=0.03, P=0.01, P=0.01) and on leukemia-free survival (P=0.006, P<0.0001, P=0.003), respectively.


Sujet(s)
Antinéoplasiques/usage thérapeutique , Composés de l'arsenic/usage thérapeutique , Leucémie aiguë promyélocytaire/traitement médicamenteux , Oxydes/usage thérapeutique , Adolescent , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Trioxyde d'arsenic , Différenciation cellulaire , Enfant , Enfant d'âge préscolaire , Survie sans rechute , Europe , Femelle , Humains , Coopération internationale , Leucémie aiguë promyélocytaire/anatomopathologie , Mâle , Adulte d'âge moyen , Études prospectives , Récidive , Enregistrements , Résultat thérapeutique , Jeune adulte
10.
Bone Marrow Transplant ; 50(4): 485-92, 2015 Apr.
Article de Anglais | MEDLINE | ID: mdl-25599163

RÉSUMÉ

Non-relapse mortality after Allo-SCT has significantly decreased over the last years. Nevertheless, relapse remains a major cause for post SCT mortality in patients with AML and high-risk myelodysplastic syndrome (MDS). In this retrospective single-center analysis, we have analyzed the treatment outcomes of 108 patients with AML or MDS, who relapsed after Allo-SCT. Seventy of these patients (65%) were treated with salvage therapies containing chemotherapy alone, allogeneic cell-based treatment or the combination of both. Thirty-eight patients (35%) received palliative treatment. Median OS after diagnosis of relapse was 130 days. Compared with patients who received chemotherapy alone, response to salvage therapy was significantly improved in patients treated with a combination of chemo- and allogeneic cell-based therapy (CR rate 57% vs 13%, P=0.002). Among risk factors concerning pretreatment characteristics, disease status before first Allo-SCT, and details of transplantation, only the time interval from Allo-SCT to relapse was an independent predictor of response to salvage therapy and OS. These data confirmed that time to relapse after transplantation is an important prognostic factor. Up to now, only patients eligible for treatment regimens containing allogeneic cell-based interventions achieved relevant response rates.


Sujet(s)
Transplantation de cellules souches hématopoïétiques , Leucémie aigüe myéloïde/mortalité , Leucémie aigüe myéloïde/thérapie , Syndromes myélodysplasiques/mortalité , Syndromes myélodysplasiques/thérapie , Thérapie de rattrapage , Adolescent , Adulte , Sujet âgé , Allogreffes , Survie sans rechute , Femelle , Humains , Mâle , Adulte d'âge moyen , Récidive , Études rétrospectives , Taux de survie , Facteurs temps
11.
Infection ; 43(3): 287-95, 2015 Jun.
Article de Anglais | MEDLINE | ID: mdl-25575463

RÉSUMÉ

OBJECTIVE: To identify factors associated with short-term, intermediate and long-term outcome in patients with infective endocarditis (IE) and the need for treatment on intensive care unit (ICU). DESIGN AND SETTING: Retrospective analysis and long-term follow-up by questionnaire in the two medical ICUs of our university hospital. PATIENTS: We conducted a retrospective analysis of all consecutive patients with IE and need for ICU treatment in our department between 2002 and 2009. All patients fulfilled the modified Duke criteria for definite diagnosis of IE. MEASUREMENTS AND MAIN RESULTS: Data of 216 patients (aged 62 ± 14 years, 31 % female) were analyzed, 15.7 % of whom had prosthetic valve endocarditis. Infectious agent (IA) was identified in 74 % and surgery was performed in 57 %. 56 patients (24.9 %) died on ICU, 9 patients were sent to palliative care units and died several days later. During follow-up, another 44 patients died. Multivariate Cox-regression analysis identified the following independent risk factors: High initial SAPS II for 30d-, multiple organ failure and high maximum SAPS II for 100d- and high maximum leukocyte count for long-term mortality. Surgical intervention during ICU was an independent predictor of a better 30d outcome. CONCLUSIONS: In contrast to general IE populations, IA and the type of infected impaired valve are not main predictors of survival in critically ill IE-patients. Biomarker of acute infection and markers for severity of illness (scores and organ failure) are independent risk factors for mortality. The surgical clearance of infected valve, device or abscesses is an independent predictor of 30d outcome.


Sujet(s)
Endocardite/épidémiologie , Unités de soins intensifs , Adolescent , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Endocardite/mortalité , Femelle , Études de suivi , Humains , Mâle , Adulte d'âge moyen , Études rétrospectives , Facteurs de risque , Enquêtes et questionnaires , Analyse de survie , Résultat thérapeutique , Jeune adulte
12.
Virology ; 289(2): 186-91, 2001 Oct 25.
Article de Anglais | MEDLINE | ID: mdl-11689041

RÉSUMÉ

Nuclear import of some viral proteins depends on importin alpha proteins. However, no preferences of distinct alpha-importins for any viral protein import have been demonstrated. We used in vitro import assays and observed that all ubiquitously expressed human importin alpha isoforms mediate nuclear translocation of adenoviral E1A. Competition with nucleoplasmin suggests that importin alpha3 is the most efficient import mediator of E1A.


Sujet(s)
Protéines E1A d'adénovirus/métabolisme , Helicase/métabolisme , Cariophérines alpha/métabolisme , Noyau de la cellule/métabolisme , Cellules HeLa , Humains , Protéines nucléaires/métabolisme , Nucléoplasmines , Phosphoprotéines/métabolisme , Transport des protéines
13.
J Cell Sci ; 114(Pt 19): 3479-85, 2001 Oct.
Article de Anglais | MEDLINE | ID: mdl-11682607

RÉSUMÉ

The signal recognition particle (SRP) is a cytoplasmic RNA-protein complex that targets proteins to the rough endoplasmic reticulum. Although SRP functions in the cytoplasm, RNA microinjection and cDNA transfection experiments in animal cells, as well as genetic analyses in yeast, have indicated that SRP assembles in the nucleus. Nonetheless, the mechanisms responsible for nuclear-cytoplasmic transport of SRP RNA and SRP proteins are largely unknown. Here we show that the 19 kDa protein subunit of mammalian SRP, SRP19, was efficiently imported into the nucleus in vitro by two members of the importin beta superfamily of transport receptors, importin 8 and transportin; SRP19 was also imported less efficiently by several other members of the importin beta family. Although transportin is known to import a variety of proteins, SRP19 import is the first function assigned to importin 8. Furthermore, we show that a significant pool of endogenous SRP19 is located in the nucleus, as well as the nucleolus. Our results show that at least one mammalian SRP protein is specifically imported into the nucleus, by members of the importin beta family of transport receptors, and the findings add additional evidence for nuclear assembly of SRP.


Sujet(s)
Noyau de la cellule/métabolisme , Caryophérines/métabolisme , Protéines nucléaires/métabolisme , Particule de reconnaissance du signal/métabolisme , Protéine G ran/métabolisme , Transport nucléaire actif/physiologie , Noyau de la cellule/composition chimique , Cellules HeLa , Humains , Caryophérines/analyse , Protéines nucléaires/analyse , Récepteurs cytoplasmiques et nucléaires , Particule de reconnaissance du signal/analyse , Caryophérines bêta/analyse , Caryophérines bêta/métabolisme , Protéine G ran/analyse
14.
EMBO J ; 20(14): 3685-94, 2001 Jul 16.
Article de Anglais | MEDLINE | ID: mdl-11447110

RÉSUMÉ

Importin beta-related receptors mediate translocation through nuclear pore complexes. Co-operation with the RanGTPase system allows them to bind and subsequently release their substrates on opposite sides of the nuclear envelope, which in turn ensures a directed nucleocytoplasmic transport. Here we identify a novel family member from higher eukaryotes that functions primarily, but not exclusively, in import. It accounts for nuclear accumulation of the SUMO-1/sentrin-conjugating enzyme hUBC9 and mediates import of the RBM8 (Y14) protein, and is therefore referred to as importin 13 (Imp13). Unexpectedly, Imp13 also shows export activity towards the translation initiation factor eIF1A and is thus a case where a single importin beta-like receptor transports different substrates in opposite directions. However, Imp13 operates differently from typical exportins in that the binding of eIF1A to Imp13 is only regulated indirectly by RanGTP, and the cytoplasmic release of eIF1A from Imp13 is triggered by the loading of import substrates onto Imp13.


Sujet(s)
Noyau de la cellule/métabolisme , Facteur-1 d'initiation eucaryote , Protéines nucléaires/physiologie , Transport des protéines/physiologie , Ubiquitin-conjugating enzymes , Cellules HeLa , Humains , Caryophérines , Ligases/métabolisme , Données de séquences moléculaires , Facteurs initiation chaîne peptidique/métabolisme , Protéines de liaison à l'ARN/métabolisme , Protéine SUMO-1 , Ubiquitines/métabolisme
15.
Cell Death Differ ; 8(5): 495-505, 2001 May.
Article de Anglais | MEDLINE | ID: mdl-11423910

RÉSUMÉ

In eukaryotic cells, both soluble transport factors and components of the nuclear pore complex mediate protein and RNA trafficking between the nucleus and the cytoplasm. Here, we investigated whether caspases, the major execution system in apoptosis, target the nuclear pore or components of the nuclear transport machinery. Four nucleoporins, Nup153, RanBP2, Nup214 and Tpr are cleaved by caspases during apoptosis. In contrast, the nuclear transport factors, Ran, importin alpha and importin beta are not proteolytically processed, but redistribute across the nuclear envelope independently and prior to caspase activation. Also, mRNA accumulates into the nucleus before caspases become active. Microinjection experiments further revealed that early in apoptosis, the nucleus becomes permeable to dextran molecules of 70 kD molecular weight. Redistribution of import factors and mRNA, as well as nuclear permeabilisation, occur prior to caspase-mediated nucleoporin cleavage. Our findings suggest that the apoptotic programme includes modifications in the machinery responsible for nucleocytoplasmic transport, which are independent from caspase-mediated degradation of nuclear proteins.


Sujet(s)
Apoptose , Caspases/métabolisme , Enveloppe nucléaire/métabolisme , Complexe protéique du pore nucléaire , Protéines nucléaires/métabolisme , Transport nucléaire actif/effets des médicaments et des substances chimiques , Apoptose/effets des médicaments et des substances chimiques , Inhibiteurs des caspases , Protéines de liaison à l'ADN/métabolisme , Dactinomycine/pharmacologie , Activation enzymatique/effets des médicaments et des substances chimiques , Femelle , Cellules HeLa , Humains , Immunohistochimie , Caryophérines , Microscopie de fluorescence , Chaperons moléculaires , Enveloppe nucléaire/effets des médicaments et des substances chimiques , Pore nucléaire/composition chimique , Pore nucléaire/effets des médicaments et des substances chimiques , Pore nucléaire/métabolisme , Perméabilité/effets des médicaments et des substances chimiques , Protéines proto-oncogènes/métabolisme , ARN messager/génétique , ARN messager/métabolisme , Transduction du signal/effets des médicaments et des substances chimiques , Staurosporine/pharmacologie , Protéine G ran/métabolisme
16.
EMBO J ; 20(6): 1320-30, 2001 Mar 15.
Article de Anglais | MEDLINE | ID: mdl-11250898

RÉSUMÉ

The mechanism of facilitated translocation through nuclear pore complexes (NPCs) is only poorly understood. Here, we present a kinetic analysis of the process using various model substrates. We find that the translocation capacity of NPCs is unexpectedly high, with a single NPC allowing a mass flow of nearly 100 MDa/s and rates in the order of 10(3) translocation events per second. Our data further indicate that high affinity interactions between the translocation substrate and NPC components are dispensable for translocation. We propose a 'selective phase model' that could explain how NPCs function as a permeability barrier for inert molecules and yet become selectively permeable for nuclear transport receptors and receptor-cargo complexes.


Sujet(s)
Protéines de transport/métabolisme , Protéines luminescentes/métabolisme , Pore nucléaire/métabolisme , Protéines nucléaires/métabolisme , Transporteurs nucléocytoplasmiques , Récepteurs cytoplasmiques et nucléaires/métabolisme , Transport nucléaire actif , Diffusion , Protéines à fluorescence verte , Cellules HeLa , Humains , Caryophérines , Modèles théoriques
17.
Genetics ; 156(4): 1889-900, 2000 Dec.
Article de Anglais | MEDLINE | ID: mdl-11102382

RÉSUMÉ

The Drosophila melanogaster Ketel gene was identified via the Ketel(D) dominant female sterile mutations and their ketel(r) revertant alleles that are recessive zygotic lethals. The maternally acting Ketel(D) mutations inhibit cleavage nuclei formation. We cloned the Ketel gene on the basis of a common breakpoint in 38E1. 2-3 in four ketel(r) alleles. The Ketel(+) transgenes rescue ketel(r)-associated zygotic lethality and slightly reduce Ketel(D)-associated dominant female sterility. Ketel is a single copy gene. It is transcribed to a single 3.6-kb mRNA, predicted to encode the 97-kD Ketel protein. The 884-amino-acid sequence of Ketel is 60% identical and 78% similar to that of human importin-beta, the nuclear import receptor for proteins with a classical NLS. Indeed, Ketel supports import of appropriately designed substrates into nuclei of digitonin-permeabilized HeLa cells. As shown by a polyclonal anti-Ketel antibody, nurse cells synthesize and transfer Ketel protein into the oocyte cytoplasm from stage 11 of oogenesis. In cleavage embryos the Ketel protein is cytoplasmic. The Ketel gene appears to be ubiquitously expressed in embryonic cells. Western blot analysis revealed that the Ketel gene is not expressed in several larval cell types of late third instar larvae.


Sujet(s)
Drosophila melanogaster/génétique , Gènes d'insecte , Protéines d'insecte/génétique , Protéines nucléaires/génétique , Transport des protéines/génétique , Séquence d'acides aminés , Animaux , Animal génétiquement modifié , Noyau de la cellule/métabolisme , Clonage moléculaire , Cytoplasme/métabolisme , ADN complémentaire/génétique , Drosophila melanogaster/embryologie , Embryon non mammalien/cytologie , Embryon non mammalien/métabolisme , Femelle , Gènes dominants , Gènes létaux , Cellules HeLa/métabolisme , Humains , Infertilité féminine/génétique , Caryophérines , Données de séquences moléculaires , Protéines nucléaires/physiologie , Spécificité d'organe , Alignement de séquences , Similitude de séquences d'acides aminés , Spécificité d'espèce , Transgènes , Zygote
18.
J Biol Chem ; 275(51): 40163-8, 2000 Dec 22.
Article de Anglais | MEDLINE | ID: mdl-11024021

RÉSUMÉ

Nucleo-cytoplasmic transport comprises a large number of distinct pathways, many of which are defined by members of the importin beta superfamily of nuclear transport receptors. These transport receptors all directly interact with RanGTP to modulate the compartment-specific binding of their transport substrates. To identify new members of the importin beta family, we used affinity chromatography on immobilized RanGTP and isolated Ran-binding protein (RanBP) 16 from HeLa cell extracts. RanBP16 and its close human homologue, RanBP17, are distant members of the importin beta family. Like the other members of the transport receptor superfamily, RanBP16 interacts with the nuclear pore complex and is able to enter the nucleus independent of energy and additional nuclear transport receptors.


Sujet(s)
Protéines nucléaires/métabolisme , Protéine G ran/métabolisme , Séquence d'acides aminés , Animaux , Séquence nucléotidique , Amorces ADN , Cellules HeLa , Humains , Caryophérines , Données de séquences moléculaires , Similitude de séquences d'acides aminés , Protéine G ran/composition chimique
19.
Biochemistry ; 39(38): 11629-39, 2000 Sep 26.
Article de Anglais | MEDLINE | ID: mdl-10995230

RÉSUMÉ

The cytoplasmic disassembly of Ran.GTP.importin and Ran.GTP.exportin. cargo complexes is an essential step in the corresponding nuclear import and export cycles. It has previously been shown that such disassembly can be mediated by RanBP1 in the presence of RanGAP. The nuclear pore complex protein RanBP2 (Nup358) contains four Ran-binding domains (RanBDi) that might function like RanBP1. We used biophysical assays based on fluorescence-labeled probes and on surface plasmon resonance to investigate the dynamic interplay of Ran in its GDP- and GTP-complexed states with RanBDis and with importin-beta. We show that RanBP1 and the four RanBDis from RanBP2 have comparable affinities for Ran.GTP (10(8)-10(9) M(-1)). Deletion of Ran's C-terminal (211)DEDDDL(216) sequence weakens the interaction of Ran.GTP with RanBPis approximately 2000-fold, but accelerates the association of Ran.GTP with importin-beta 10-fold. Importin-beta binds Ran.GTP with a moderate rate, but attains a high affinity for Ran (K(D) = 140 pM) via an extremely low dissociation rate of 10(-5) s(-)(1). Association with Ran is accelerated 3-fold in the presence of RanBP1, which presumably prevents steric hindrance caused by the Ran C-terminus. In addition, we show that the RanBDis of RanBP2 are full equivalents of RanBP1 in that they also costimulate RanGAP-catalyzed GTP hydrolysis in Ran and relieve the GTPase block in a Ran.GTP.transportin complex. Our data suggest that the C-terminus of Ran functions like a loose tether in Ran.GTP complexes of importins or exportins that exit the nucleus. This flag is then recognized by the multiple RanBDis at or near the nuclear pore complex, allowing efficient disassembly of these Ran.GTP complexes.


Sujet(s)
Protéines de liaison à l'ADN/métabolisme , Complexe protéique du pore nucléaire , Protéines nucléaires/métabolisme , Protéine G ran/composition chimique , Motifs d'acides aminés , Séquence d'acides aminés , Catalyse , Séquence conservée , Protéines de liaison à l'ADN/composition chimique , Guanosine triphosphate/métabolisme , Humains , Hydrolyse , Caryophérines , Cinétique , Structures macromoléculaires , Chaperons moléculaires , Données de séquences moléculaires , Protéines nucléaires/composition chimique , Fragments peptidiques/composition chimique , Fragments peptidiques/métabolisme , Liaison aux protéines , Structure tertiaire des protéines , Spectrométrie de fluorescence , Relation structure-activité , Thermodynamique , Protéine G ran/métabolisme
20.
EMBO J ; 19(16): 4362-71, 2000 Aug 15.
Article de Anglais | MEDLINE | ID: mdl-10944119

RÉSUMÉ

Transport receptors of the importin beta superfamily account for many of the nuclear import and export events in eukaryotic cells. They mediate translocation through nuclear pore complexes, shuttle between nucleus and cytoplasm and co-operate with the RanGTPase system to regulate their interactions with cargo molecules in a compartment-specific manner. We used affinity chromatography on immobilized RanGTP to isolate further candidate nuclear transport receptors and thereby identified exportin 4 as the most distant member of the importin beta family so far. Exportin 4 appears to be conserved amongst higher eukaryotes, but lacks obvious orthologues in yeast. It mediates nuclear export of eIF-5A (eukaryotic translation initiation factor 5A) and possibly that of other cargoes. The export signal in eIF-5A appears to be complex and to involve the hypusine modification that is unique to eIF-5A. We discuss possible cellular roles for nuclear export of eIF-5A.


Sujet(s)
Protéines de transport/physiologie , Noyau de la cellule/métabolisme , Lysine/analogues et dérivés , Protéines de liaison à l'ARN/physiologie , Séquence d'acides aminés , Animaux , Chromatographie d'affinité , Clonage moléculaire , Cytoplasme/métabolisme , ADN complémentaire/métabolisme , Relation dose-effet des médicaments , dGTPases/métabolisme , Cellules HeLa , Humains , Caryophérines , Cinétique , Lysine/métabolisme , Souris , Microscopie de fluorescence , Données de séquences moléculaires , Protéines nucléaires/génétique , Protéines nucléaires/métabolisme , Facteurs initiation chaîne peptidique/métabolisme , Liaison aux protéines , Structure tertiaire des protéines , ARN/métabolisme , Facteurs temps , Protéine G ran/métabolisme ,
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