Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 17 de 17
Filter
1.
Hematol Oncol ; 39(2): 196-204, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33300135

ABSTRACT

Hodgkin lymphoma (HL) in older patients appears to be a different disease compared with younger patients with historically lower survival rates. This is related to a variety of factors, including increased treatment-related toxicity, the presence of comorbidities, and biologic differences. In order to better assess the clinical characteristics, treatment strategies, and outcome of this particular population, we conducted a population-based, retrospective analysis including 269 patients with HL older than 60 years (median age 71 years, range 60-94), treated between 2000 and 2017 in 15 referral centers across Switzerland. Primary endpoints were overall survival (OS), progression-free survival (PFS), and cause-specific survival (CSS). The vast majority of patients were treated with curative intent, either with a combined modality approach (chemotherapy followed by radiation therapy) or with systemic therapy. At a median follow-up of 6.6 years (95% confidence interval [CI], 6.0-7.6), 5-year PFS was 52.2% (95% CI, 46.0-59.2), 5-year OS was 62.5% (95% CI, 56.4-69.2), and 5-year CSS was 85.1.8% (95% CI, 80.3-90.1) for the entire cohort. A significant difference in terms of CSS was observed for patients older than 71 years in comparison to patients aged 60-70 years (hazard ratio 2.6, 1.3-5.0, p = 0.005). Bleomycin-induced lung toxicity (BLT) was documented in 26 patients (17.7%) out of the 147 patients exposed to this compound and was more frequent in patients older than 71 years (15/60, 25%). Outcome of HL pts older than 71 years appeared to decrease substantially in comparison to the younger counterpart. Treatment-related toxicities appeared to be relevant, in particular, BLT. New, potentially less toxic strategies need to be investigated in prospective clinical trials in this particular frail population.


Subject(s)
Hodgkin Disease/epidemiology , Age Factors , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Retrospective Studies , Switzerland
2.
Eur J Neurol ; 23(5): 861-70, 2016 May.
Article in English | MEDLINE | ID: mdl-26848561

ABSTRACT

BACKGROUND AND PURPOSE: Combining different therapies may improve disease control in patients with relapsing-remitting multiple sclerosis (RRMS). This study assessed the efficacy and safety of minocycline added to subcutaneous (sc) interferon (IFN) ß-1a therapy. METHODS: This was a double-blind, randomized, placebo-controlled multicentre study. Within 3 months (±1 month) of starting sc IFN ß-1a 44 µg three times weekly, patients with RRMS were randomized to minocycline 100 mg twice daily or placebo, added to sc IFN ß-1a, for 96 weeks. The primary efficacy endpoint was the time to first qualifying relapse. Secondary efficacy endpoints were the annualized relapse rate for qualifying relapses, the number of new/enlarging T2-weighted lesions and change in brain volume [magnetic resonance imaging (MRI) was performed only in a few selected centres]. In addition, a number of tertiary efficacy endpoints were assessed. RESULTS: One hundred and forty-nine patients received minocycline and 155 received placebo; MRI data were available for 23 and 27 patients, respectively. The time to first qualifying relapse did not differ significantly for minocycline versus placebo (hazard ratio 0.85; 95% confidence interval 0.53, 1.35; log-rank = 0.50; P = 0.48). There were no statistically significant differences between the two groups on other efficacy endpoints, although some numerical trends in favour of minocycline were observed. No unexpected adverse events were reported, but more patients discontinued because of adverse events with minocycline versus placebo. CONCLUSION: Minocycline showed no statistically significant beneficial effect when added to sc IFN ß-1a therapy.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Interferon beta-1a/therapeutic use , Minocycline/therapeutic use , Multiple Sclerosis/drug therapy , Adolescent , Adult , Brain/diagnostic imaging , Brain/drug effects , Brain/pathology , Double-Blind Method , Drug Therapy, Combination , Female , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Multiple Sclerosis/diagnostic imaging , Multiple Sclerosis/pathology , Organ Size/drug effects , Treatment Outcome , Young Adult
3.
Diabet Med ; 29(6): 734-41, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22150609

ABSTRACT

AIMS: The relation of disease progression and age, serum interleukin 10 (IL-10) and interferon gamma (IFNγ) and their genetic correlates were studied in paediatric patients with newly diagnosed Type 1 diabetes. METHODS: Two hundred and twenty-seven patients from the Hvidoere Study Group were classified in four different progression groups as assessed by change in stimulated C-peptide from 1 to 6 months. CA repeat variants of the IL-10 and IFNγ gene were genotyped and serum levels of IL-10 and IFNγ were measured at 1, 6 and 12 months. RESULTS: IL-10 decreased (P < 0.001) by 7.7% (1 month), 10.4% (6 months) and 8.6% (12 months) per year increase in age of child, while a twofold higher C-peptide concentration at 1 month (p = 0.06), 6 months (P = 0.0003) and 12 months (P = 0.02) was associated with 9.7%, 18.6% and 9.7% lower IL-10 levels, independent of each other. IL-10 concentrations did not associate with the disease progression groups. By contrast, IFNγ concentrations differed between the four progression groups at 6 and 12 months (P = 0.02 and P = 0.01, respectively); patients with rapid progressing disease had the highest levels at both time points. Distribution of IL-10 and IFNγ genotypes was equal among patients from the progression groups. CONCLUSION: IL-10 serum levels associate inversely with age and C-peptide. As age and C-peptide also associate, a triangular association is proposed. Genetic influence on IL-10 production seems to be masked by distinct disease mechanisms. Increased serum IFNγ concentrations associate with rapid disease progression. Functional genetic variants do not associate with a single progression pattern group, implying that disease processes override genetically predisposed cytokine production.


Subject(s)
Aging/blood , C-Peptide/blood , Diabetes Mellitus, Type 1/blood , Interferon-gamma/blood , Interleukin-10/blood , Adolescent , Aging/genetics , Biomarkers/blood , C-Peptide/genetics , Child , Child, Preschool , Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 1/physiopathology , Disease Progression , Fasting , Female , Genetic Predisposition to Disease , Humans , Infant , Interferon-gamma/genetics , Interleukin-10/genetics , Male
4.
Diabetologia ; 54(7): 1630-8, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21347621

ABSTRACT

AIMS/HYPOTHESIS: Systemic pro- and anti-inflammatory cytokines are associated with both type 1 and type 2 diabetes, while their role in latent autoimmune diabetes in adults (LADA) is unclear. Therefore, we compared cytokine concentrations in patients with LADA, type 1 or type 2 diabetes and healthy individuals to test the hypothesis that differences of cytokine concentrations between all groups are attributable to diabetes type and BMI. METHODS: The pro-inflammatory cytokines IL-6 and TNF-α, and the anti-inflammatory cytokines IL-1 receptor antagonist (IL-1RA) and IL-10 were measured in 90 participants with type 1 diabetes, 61 with LADA, 465 with type 2 diabetes and 41 control participants using multiple regression models adjusted for BMI, sex, age, blood pressure and diabetes duration. RESULTS: Patients with type 2 diabetes had higher concentrations of systemic IL-1RA, IL-6 and TNF-α cytokines than patients with either LADA or type 1 diabetes (p < 0.0001 for all differences). Cytokine concentrations in controls were lower than those in all diabetes types (p < 0.04). Increased BMI was positively associated with higher systemic cytokine concentrations in all diabetes types (p < 0.0001). Despite the association of cytokines with anthropometric data, differences between diabetes forms persisted also after adjusting analysis for the confounders BMI, age, sex, disease duration and blood pressure (p < 0.04). CONCLUSIONS/INTERPRETATION: Although body mass associates positively with pro- and anti-inflammatory cytokine levels, patients with type 2 diabetes have higher cytokine levels independent of the prevailing BMI. LADA and type 1 diabetes could not be distinguished by systemic cytokines.


Subject(s)
Cytokines/blood , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 2/blood , Adult , Aged , Female , Humans , Interleukin 1 Receptor Antagonist Protein/blood , Interleukin-10/blood , Interleukin-6/blood , Male , Middle Aged , Tumor Necrosis Factor-alpha/blood
5.
Clin Exp Immunol ; 161(3): 444-52, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20529086

ABSTRACT

The progression of type 1 diabetes after diagnosis is poorly understood. Our aim was to assess the relation of disease progression of juvenile-onset type 1 diabetes, determined by preserved beta cell function the first year after diagnosis, with systemic cytokine concentrations and number of autoantibodies. Juvenile patients (n = 227) had a meal-stimulated C-peptide test 1 and 6 months after diagnosis. On the basis of the C-peptide course for the duration of 1-6 months, four progression groups were defined: patients with persistently low beta cell function ('stable-low'), rapid progressers, slow progressers and remitters. Serum concentrations of adiponectin, interleukin (IL)-1ra, inducible protein 10 (IP-10), IL-6 and glutamic acid decarboxylase (GAD), IA-2A and islet-cell antibodies (ICA) were measured at 1, 6 and 12 months. We found that adiponectin concentrations at 1 month predicted disease progression at 6 months (P = 0·04). Patients with low adiponectin had a higher probability of becoming remitters than rapid progressers, odds ratio 3·1 (1·3-7·6). At 6 and 12 months, adiponectin differed significantly between the groups, with highest concentrations among stable-low and rapid progressers patients (P = 0·03 and P = 0·006). IL-1ra, IP-10 and IL-6 did not differ between the groups at any time-point. The number of autoantibodies differed significantly between the groups at 1 month (P = 0·04), where rapid progressers had the largest number. There was no difference between the groups in human leucocyte antigen-associated risk. We define progression patterns distinguishing patients diagnosed with low beta cell function from those with rapid decline, slow decline or actual increase in beta cell function, pointing to different mechanisms of disease progression. We find that adiponectin concentration at 1 month predicts, and at 6 and 12 months associates with, distinct progression patterns.


Subject(s)
Adiponectin/blood , Autoantibodies/blood , Chemokine CXCL10/blood , Diabetes Mellitus, Type 1/blood , Interleukin 1 Receptor Antagonist Protein/blood , Interleukin-6/blood , Adolescent , C-Peptide/blood , Child , Child, Preschool , Diabetes Mellitus, Type 1/diagnosis , Diabetes Mellitus, Type 1/immunology , Disease Progression , Female , Humans , Infant , Male , Predictive Value of Tests , Prospective Studies , Time Factors
6.
Histochem Cell Biol ; 134(1): 31-8, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20563595

ABSTRACT

It has recently been shown in epithelial cells that the ATP-gated ion channel P2X7R is in part, associated with caveolae and colocalized with caveolin-1. In the present study of the mouse heart, we show for the first time, using immunohistochemistry and cryoimmunoelectron microscopy, that P2X7R is expressed in atrial cardiomyocytes and in cardiac microvascular endothelial cells, but not in the ventricle cardiomyocytes. Furthermore, biochemical data indicate the presence of two forms of P2X7R, the classical glycosylated 80 kDa isoform and a protein with the molecular weight of 56 kDa, in both cardiomyocytes and endothelial cells of the mouse heart. The functionality of both proteins in heart cells is still unclear. In cardiac tissue homogenates derived from caveolin-1 deficient mice (cav-1(-/-)), an increase of the P2Xrx7 mRNA and P2X7R protein (80 kDa) was found, particularly in atrial samples. In addition, P2rx7(-/-) mice showed enhanced protein levels of caveolin-1 in their atrial tissues. Although the details of cellular mechanisms that underlie the relationship between caveolin-1 and P2X7R in atrial cardiomyocytes and the electrophysiological consequences of the increased P2X7R expression in atrial cells of cav-1(-/-) mice remain to be elucidated, the cardiomyopathy detectable in cav-1(-/-) mice is possibly related to a disturbed crosstalk between P2X7R and caveolin-1 in different heart cell populations.


Subject(s)
Caveolin 1/deficiency , Heart Atria/cytology , Myocytes, Cardiac/metabolism , Receptors, Purinergic P2/biosynthesis , Receptors, Purinergic P2/genetics , Animals , Blotting, Western , Female , Immunohistochemistry , Mice , RNA, Messenger/genetics , Receptors, Purinergic P2X7 , Reverse Transcriptase Polymerase Chain Reaction
7.
Mult Scler ; 16(7): 878-82, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20483882

ABSTRACT

BACKGROUND: There is a need for follow-up studies of the familial situation of multiple sclerosis (MS) patients. OBJECTIVES: To evaluate the probability of MS patients to remain in marriage or relationship with the same partner after onset of MS in comparison with the population. PATIENTS AND METHODS: All 2538 Danes with onset of MS 1980-1989, retrieved from the Danish MS-Registry, and 50,760 matched and randomly drawn control persons were included. Information on family status was retrieved from Statistics Denmark. Cox analyses were used with onset as starting point. RESULTS: Five years after onset, the cumulative probability of remaining in the same relationship was 86% in patients vs. 89% in controls. The probabilities continued to deviate, and at 24 years, the probability was 33% in patients vs. 53% in the control persons (p < 0.001). Among patients with young onset (< 36 years of age), those with no children had a higher risk of divorce than those having children less than 7 years (Hazard Ratio 1.51; p < 0.0001), and men had a higher risk of divorce than women (Hazard Ratio 1.33; p < 0.01). CONCLUSION: MS significantly affects the probability of remaining in the same relationship compared with the background population.


Subject(s)
Cost of Illness , Divorce , Family Relations , Multiple Sclerosis/psychology , Spouses/psychology , Adult , Age of Onset , Case-Control Studies , Denmark/epidemiology , Divorce/statistics & numerical data , Family Characteristics , Female , Humans , Logistic Models , Male , Multiple Sclerosis/epidemiology , Proportional Hazards Models , Prospective Studies , Registries , Risk Assessment , Risk Factors , Sex Factors , Time Factors
8.
Eur J Neurol ; 17(11): 1346-51, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20402759

ABSTRACT

BACKGROUND: Time to disability pension is one of the endpoints to be used to determine the prognosis of multiple sclerosis (MS) in prospective studies. OBJECTIVE: To assess the time to cessation of work and receiving disability pension in MS, and how it may depend on gender, type of work and age and symptom at onset. METHOD: A total of 2240 Danes with onset of definite/probable MS 1980-1989, identified from the Danish MS-Registry, were included. Information on social endpoints was retrieved from Statistics Denmark. Cox regression analyses were used with onset as starting point. RESULTS: Afferent onset symptoms [hazard ratio (HR 0.57)] and non-physical type of work (HR 0.70) were favourable prognostic factors compared with high age at onset, physical work and efferent symptoms at onset. The mean time to disability pension was 13 years for patients with afferent/brainstem onset symptom but 8.7 years for those with efferent onset symptoms (P < 0.0001). The effect of onset symptom was reduced and the effect of sex became significant when all covariates and age at onset were included in multivariate Cox regression. CONCLUSIONS: Onset age, type of onset symptom and work are robust predictors of disability pension in MS. Disability pension proves to be a reliable milestone in estimation of the prognosis of MS.


Subject(s)
Demography , Multiple Sclerosis/economics , Multiple Sclerosis/epidemiology , Pensions/statistics & numerical data , Retirement/statistics & numerical data , Age of Onset , Cohort Studies , Denmark , Disability Evaluation , Disabled Persons/statistics & numerical data , Disease Progression , Female , Humans , Male , Predictive Value of Tests , Probability , Prognosis , Proportional Hazards Models
9.
Mult Scler ; 15(3): 294-8, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19028828

ABSTRACT

BACKGROUND: The idea of physical trauma being involved in the causation of multiple sclerosis (MS) had been discussed since the earliest description of the illness. Despite the ongoing debate, the proposed association between physical and especially head trauma and MS failed to be proved or to be refuted conclusively. OBJECTIVE: To determine whether head trauma is associated with an increased risk of developing MS. METHOD: A cohort of 150,868 subjects, 95,111 men, and 55,757 women registered in the National Danish Patient Registry with hospital admission for cerebral concussion, contusion, or skull fracture between 1977 and 1992, aged under 55, was selected. This trauma cohort was linked with the Danish MS Registry and followed up to the end of 1999 to retrieve subjects who had onset of MS after the year of the head trauma. We calculated the expected number of subjects, who, under a null-hypothesis, would subsequently develop MS, by using population age-, year-, and sex-specific MS-incidence densities from the Danish MS Registry. RESULTS: For men and women combined, the observed to expected number of MS cases (possible cases included) with onset after the head injury was 182/193.6 (standardized incidence ratio [SIR], 0.94; 95% CI, 0.81-1.09) and for possible MS excluded, 171/164.7 (SIR, 1.04; 95% CI, 0.89-1.21). In an analysis of a sub-cohort of 16,425 subjects with severe trauma (contusion, traumatic cerebral hemorrhage, and base or skull fracture), the observed to expected numbers, including possible MS, were 15/15.3 (SIR, 0.98; 95% CI, 0.55-1.62) and with possible MS excluded, 13/12.9 (SIR, 1.01; 95% CI, 0.53-1.73). As for the total group and for any of the subgroups and for men and women separately, none of the SIRs differed statistically significantly from unity. Neither were there any trends, which could be missed by type II errors. CONCLUSION: Head injury of any severity does not affect the risk of acquiring MS later in life.


Subject(s)
Craniocerebral Trauma/epidemiology , Multiple Sclerosis/epidemiology , Adolescent , Adult , Child , Child, Preschool , Cohort Studies , Female , Humans , Male , Middle Aged , Prospective Studies , Risk Factors , Young Adult
10.
Clin Immunol ; 128(1): 57-65, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18434252

ABSTRACT

Th1 related chemokines CCL3 and CCL5 and Th2 related CCL4 as ligands of the receptor CCR5 contribute to disease development in animal models of type 1 diabetes. In humans, no data are available addressing the role of these chemokines regarding disease progression and remission. We investigated longitudinally circulating concentrations of CCR5 ligands of 256 newly diagnosed patients with type 1 diabetes. CCR5 ligands were differentially associated with beta-cell function and clinical remission. CCL5 was decreased in remitters and positively associated with HbA1c suggestive of a Th1 associated progression of the disease. Likewise, CCL3 was negatively related to C-peptide and positively associated with the beta-cell stress marker proinsulin but increased in remitters. CCL4 associated with decreased beta-cell stress shown by negative association with proinsulin. Blockage of chemokines or antagonism of CCR5 by therapeutic agents such as maraviroc may provide a new therapeutic target to ameliorate disease progression in type 1 diabetes.


Subject(s)
C-Peptide/blood , Chemokines/blood , Diabetes Mellitus, Type 1/blood , Glycated Hemoglobin/analysis , Proinsulin/blood , Receptors, CCR5/blood , Adolescent , Biomarkers/blood , Chemokine CCL3/blood , Chemokine CCL4/blood , Chemokine CCL5/blood , Child , Child, Preschool , Diabetes Mellitus, Type 1/physiopathology , Disease Progression , Enzyme-Linked Immunosorbent Assay , Female , Humans , Infant , Male
11.
Horm Metab Res ; 40(6): 416-21, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18415893

ABSTRACT

Chemokines are a group of small proteins that recruit different leukocyte subtypes to sites of inflammation and play important roles in initiating and maintaining immunological responses in autoimmune endocrine diseases including Graves' disease (GD) and Hashimoto's thyroiditis (HT). Previous studies have found increased gene and protein expression of different kinds of chemokines not only within the thyroid gland but also within thyroid cells in GD or HT patients. A few studies have determined serum levels of chemokines, with conflicting results. We measured circulating concentrations of CCL2, CCL5, CXCL9, and CXCL10 in patients with GD, HT, and nontoxic nodular thyroid disease (NNT). While CCL2 and CXCL9 concentrations were comparable in patients with either AITD or NNT, CCL5 was significantly increased in GD patients compared with HT or NNT subjects. In contrast, CXCL10 levels were lower in patients with GD, but the difference was statistically significant only when compared with patients with HT (p=0.0018). Importantly, GD patients who relapsed or went into remission had significantly different levels of CXCL9 (p=0.0252). Serum levels of CCL2, CCL5, CXCL9, and CXCL10 did not reveal any correlation with thyroid volume; with the levels of thyrotropin (TSH), FT3, or FT4; or with the titers of TSH receptor antibody and thyroperoxidase antibody. These data suggest that the expression patterns of chemokines in various thyroid diseases differ from each other, which may reflect the distinct immune responses in HT and GD.


Subject(s)
Chemokines, CC/blood , Graves Disease/immunology , Thyroiditis, Autoimmune/immunology , Adult , Age Factors , Aged , Analysis of Variance , Autoantibodies/blood , Case-Control Studies , Chemokines, CC/classification , Female , Graves Disease/blood , Humans , Immunoglobulins, Thyroid-Stimulating , Iodide Peroxidase/immunology , Matched-Pair Analysis , Middle Aged , Recurrence , Remission, Spontaneous , Thyroid Nodule/immunology , Thyroiditis, Autoimmune/blood
12.
Genes Dev ; 15(18): 2396-407, 2001 Sep 15.
Article in English | MEDLINE | ID: mdl-11562349

ABSTRACT

The specificity of ubiquitin-mediated protein degradation with regards to the selection of substrates to be polyubiquitinated has only been determined rather recently. Substrate targeting by the N-end rule and HECT (homology to E6AP carboxyl terminus) domain ubiquitin ligases occurs through substrate-specific binding domains. In contrast, the SCF complex recruits substrates through a substrate adaptor protein, the F-box subunit. Despite evidence showing that Cdc20 and Cdh1 bind and activate the anaphase-promoting complex (APC) in a substrate-specific manner, there is no evidence that the activating protein and substrate interact directly; hence, no clear model exists for the mechanism of APC activation or recruitment of substrates. We show here that the activators Cdc20 and Cdh1 can associate with substrates via their N termini. In the absence of APC, Cdc20 and Cdh1 bind substrates reflecting Cdc20-APC and Cdh1-APC specificity. The N termini of Cdc20 and Cdh1 provide specificity functionally, as demonstrated by the generation of active chimeras that display the specificity corresponding to their N termini. Thus, Cdc20 and Cdh1 act as both substrate recognition and activating modules for APC.


Subject(s)
Cell Cycle Proteins/metabolism , Fungal Proteins/metabolism , Ligases/metabolism , Saccharomyces cerevisiae Proteins , Ubiquitin-Protein Ligase Complexes , Amino Acid Sequence , Anaphase-Promoting Complex-Cyclosome , Cdc20 Proteins , Cdh1 Proteins , Cell Cycle Proteins/chemistry , Fungal Proteins/chemistry , Ligases/chemistry , Molecular Sequence Data , Sequence Homology, Amino Acid , Substrate Specificity , Ubiquitin-Protein Ligases
13.
Genes Dev ; 15(14): 1759-64, 2001 Jul 15.
Article in English | MEDLINE | ID: mdl-11459825

ABSTRACT

Exit from mitosis requires the degradation of regulatory proteins including the mitotic cyclins and securin through ubiquitination by the anaphase promoting complex (APC) bound to Cdc20 or Cdh1. Cdc20-APC is regulated through inhibition by the spindle assembly checkpoint protein MAD2. Knowledge of Cdh1-APC regulation is limited to the phosphorylation-dependent dissociation of Cdh1 from APC. We report a novel means of regulating Cdh1 by the MAD2-related gene, MAD2L2. MAD2L2 specifically binds and inhibits Cdh1-APC, paralleling the effect of MAD2 on Cdc20. We suggest that MAD2L2 and MAD2 inhibit the release of substrates from APC and propose a mechanism of inhibition.


Subject(s)
Adaptor Proteins, Signal Transducing , Carrier Proteins/metabolism , Ligases/metabolism , Mitosis/physiology , Saccharomyces cerevisiae Proteins , Ubiquitin-Protein Ligase Complexes , Amino Acid Sequence , Anaphase-Promoting Complex-Cyclosome , Animals , Calcium-Binding Proteins , Carrier Proteins/genetics , Cdc20 Proteins , Cell Cycle Proteins/metabolism , Cloning, Molecular , Fungal Proteins , Ligases/antagonists & inhibitors , Mad2 Proteins , Molecular Sequence Data , Nuclear Proteins , Protein Binding , Sequence Homology, Amino Acid , Ubiquitin-Protein Ligases , Xenopus
15.
FEBS Lett ; 481(1): 57-62, 2000 Sep 08.
Article in English | MEDLINE | ID: mdl-10984615

ABSTRACT

B99 is a p53-inducible gene whose accumulation upon p53 activation is restricted to late S/G2 cells. Here we have analyzed B99 regulation during the cell cycle in murine cells with or without functional p53. We report that B99 accumulates in late S/G2 phase, is phosphorylated in mitosis, and disappears in G1 phase, regardless of the status of p53. As a complement to this observation, we show that B99 is not induced by p53 in quiescent cells. Therefore, B99 expression is modulated both by cell-cycle regulatory mechanisms and by p53, and p53 can increase the cellular levels of B99 only during the window of the cell cycle when it is normally expressed. On the basis of these observations we rename B99 Gtse-1 (G-two- and S-phase-expressed).


Subject(s)
Cell Cycle , Microtubule-Associated Proteins/genetics , Transcriptional Activation , Tumor Suppressor Protein p53/metabolism , 3T3 Cells , Animals , Blotting, Western , Cell Extracts , G2 Phase , Gene Deletion , Mice , Mice, Inbred BALB C , Microtubule-Associated Proteins/biosynthesis , Microtubule-Associated Proteins/metabolism , Mitosis , Oocytes , Phosphorylation , Promoter Regions, Genetic/genetics , Tumor Suppressor Protein p53/genetics , Xenopus laevis
16.
Genes Dev ; 14(6): 655-65, 2000 Mar 15.
Article in English | MEDLINE | ID: mdl-10733526

ABSTRACT

The ordered progression through the cell cycle depends on regulating the abundance of several proteins through ubiquitin-mediated proteolysis. Degradation is precisely timed and specific. One key component of the degradation system, the anaphase promoting complex (APC), is a ubiquitin protein ligase. It is activated both during mitosis and late in mitosis/G(1), by the WD repeat proteins Cdc20 and Cdh1, respectively. These activators target distinct sets of substrates. Cdc20-APC requires a well-defined destruction box (D box), whereas Cdh1-APC confers a different and as yet unidentified specificity. We have determined the sequence specificity for Cdh1-APC using two assays, ubiquitination in a completely defined and purified system and degradation promoted by Cdh1-APC in Xenopus extracts. Cdc20 is itself a Cdh1-APC substrate. Vertebrate Cdc20 lacks a D box and therefore is recognized by Cdh1-APC through a different sequence. By analysis of Cdc20 as a substrate, we have identified a new recognition signal. This signal, composed of K-E-N, serves as a general targeting signal for Cdh1-APC. Like the D box, it is transposable to other proteins. Using the KEN box as a template, we have identified cell cycle genes Nek2 and B99 as additional Cdh1-APC substrates. Mutation in the KEN box stabilizes all three proteins against ubiquitination and degradation.


Subject(s)
Fungal Proteins/metabolism , Ligases/genetics , Protein Sorting Signals/metabolism , Saccharomyces cerevisiae Proteins , Ubiquitin-Protein Ligase Complexes , Amino Acid Sequence , Anaphase-Promoting Complex-Cyclosome , Animals , Binding Sites , Cdc20 Proteins , Cdh1 Proteins , Cell Cycle Proteins/metabolism , Cyclin B/chemistry , Cyclin B/metabolism , Ligases/metabolism , Molecular Sequence Data , Ubiquitin-Protein Ligases , Xenopus
17.
Development ; 122(5): 1611-20, 1996 May.
Article in English | MEDLINE | ID: mdl-8625847

ABSTRACT

During embryonic development, certain tissues stream to their destinations by liquidlike spreading movements. According to the 'differential adhesion hypothesis', these movements are guided by cell-adhesion-generated tissue surface tensions (sigmas), operating in the same manner as surface tensions do in the mutual spreading behavior of immiscible liquids, among which the liquid of lower surface tension is always the one that spreads over its partner. In order to conduct a direct physical test of the 'differential adhesion hypothesis', we have measured the sigmas of aggregates of five chick embryonic tissues, using a parallel plate compression apparatus specifically designed for this purpose, and compared the measured values with these tissues' mutual spreading behaviors. We show that aggregates of each of these tissues behave for a time as elasticoviscous liquids with characteristic surface tension values. Chick embryonic limb bud mesoderm (sigma = 20.1 dyne/cm) is enveloped by pigmented epithelium (sigma = 12.6 dyne/cm) which, in turn, is enveloped by heart (sigma = 8.5 dyne/cm) which, in turn, is enveloped by liver (sigma = 4.6 dyne/cm) which, in turn, is enveloped by neural retina (sigma = 1.6 dyne/cm). Thus, as predicted, the tissues' surface tension values fall in the precise sequence required to account for their mutual envelopment behavior.


Subject(s)
Cell Adhesion , Cell Movement , Chick Embryo/physiology , Surface Tension , Animals , Biophysics/instrumentation , Chick Embryo/cytology , Models, Biological , Morphogenesis , Organ Specificity
SELECTION OF CITATIONS
SEARCH DETAIL
...