Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 40
Filter
2.
Br J Dermatol ; 184(2): 226-236, 2021 02.
Article in English | MEDLINE | ID: mdl-32956489

ABSTRACT

Chronic urticaria (CU) affects about 1% of the world population of all ages, mostly young and middle-aged women. It usually lasts for several years (> 1 year in 25-75% of patients) and often takes > 1 year before effective management is implemented. It presents as chronic spontaneous urticaria (CSU), chronic inducible urticaria (CIndU) or both in the same person. More than 25% of cases are resistant to H1 -antihistamines, even at higher doses, and third- and fourth-line therapies (omalizumab and ciclosporin) control the disease only in two-thirds of H1 -antihistamine-resistant patients. Here we review the impact of CU on different aspects of patients' quality of life and the burden of this chronic disease for the patient and society. CU may have a strong impact on health-related quality of life (HRQoL), particularly when CSU is associated with angio-oedema and/or CIndU (Dermatology Life Quality Index > 10 in 30% of patients). Comorbidities, such as anxiety and depression, which are present in more than 30% of patients with CSU, compound HRQoL impairment. Severe pruritus and the unpredictable occurrence of weals and angio-oedema are responsible for sleep disorders; sexual dysfunction; limitations on daily life, work and sports activities; interfering with life within the family and in society; and patients' performance at school and work (6% absenteeism and 25% presenteeism). Apart from treatment costs, with annual values between 900 and 2400 purchasing power parity dollars (PPP$) in Europe and the USA, CU is associated with a high consumption of medical resources and other indirect costs, which may reach a total annual cost of PPP$ 15 550.


Subject(s)
Chronic Urticaria , Urticaria , Chronic Disease , Europe , Female , Humans , Middle Aged , Omalizumab/therapeutic use , Quality of Life , Urticaria/drug therapy , Urticaria/epidemiology
3.
Article in English | MEDLINE | ID: mdl-32206067

ABSTRACT

BACKGROUND: Oral immunotherapy (OIT) is an emerging approach to the treatment of patients with IgE-mediated food allergy and is in the process of transitioning to clinical practice. OBJECTIVE: To develop patient-oriented clinical practice guidelines on oral immunotherapy based on evidence and ethical imperatives for the provision of safe and efficient food allergy management. MATERIALS AND METHODS: Recommendations were developed using a reflective patient-centered multicriteria approach including 22 criteria organized in five dimensions (clinical, populational, economic, organizational and sociopolitical). Data was obtained from: (1) a review of scientific and ethic literature; (2) consultations of allergists, other healthcare professionals (pediatricians, family physicians, nurses, registered dieticians, psychologists, peer supporters), patients and caregivers; and patient associations through structured consultative panels, interviews and on-line questionnaire; and (3) organizational and economic data from the milieu of care. All data was synthesized by criteria in a multicriteria deliberative guide that served as a platform for structured discussion and development of recommendations for each dimension, based on evidence, ethical imperatives and other considerations. RESULTS: The deliberative grid included 162 articles from the literature and media reviews and data from consultations involving 85 individuals. Thirty-eight (38) recommendations were made for the practice of oral immunotherapy for the treatment of IgE mediated food allergy, based on evidence and a diversity of ethical imperatives. All recommendations were aimed at fostering a context conducive to achieving objectives identified by patients and caregivers with food allergy. Notably, specific recommendations were developed to promote a culture of shared responsibility between patients and healthcare system, equity in access, patient empowerment, shared decision making and personalization of OIT protocols to reflect patients' needs. It also provides recommendations to optimize organization of care to generate capacity to meet demand according to patient choice, e.g. OIT or avoidance. These recommendations were made acknowledging the necessity of ensuring sustainability of the clinical offer in light of various economic considerations. CONCLUSIONS: This innovative CPG methodology was guided by patients' perspectives, clinical evidence as well as ethical and other rationales. This allowed for the creation of a broad set of recommendations that chart optimal clinical practice and define the conditions required to bring about changes to food allergy care that will be sustainable, equitable and conducive to the well-being of all patients in need.

4.
Clin Exp Dermatol ; 43(5): 573-576, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29451318

ABSTRACT

Omalizumab (Xolair® ) is an anti-IgE monoclonal antibody, which may benefit adults with systemic mastocytosis. We report effective treatment with omalizumab in two toddlers with severe diffuse cutaneous mastocytosis. Our cases offer preliminary evidence to support the safe use of omalizumab in paediatric patients with cutaneous mastocytosis.


Subject(s)
Anti-Allergic Agents/therapeutic use , Mastocytosis, Cutaneous/drug therapy , Omalizumab/therapeutic use , Child, Preschool , Humans , Male
5.
Paediatr Child Health ; 21(2): e10-4, 2016 Mar.
Article in English | MEDLINE | ID: mdl-27095888

ABSTRACT

Primary immunodeficiencies are a group of heterogeneous disorders resulting from defects affecting the function of ≥1 parts of the immune system. Current estimates of the prevalence of primary immunodeficiency disease are one in 1200 patients. In Ontario, where the average general practitioner follows 1300 to 2000 patients, an estimated two patients will have primary immunodeficiency. With new primary immunodeficiencies being described at an exponential rate, and those previously described becoming better understood, it is challenging for health care providers to stay up to date. Knowledge gaps delay diagnosis and treatment, leading to increased morbidity and mortality. The present review aims to provide the primary care provider with the tools necessary to recognize primary immunodeficiency and assist in establishing diagnoses.


Les immunodéficiences primaires désignent un groupe de troubles hétérogènes causés par des déficits de la fonction d'au moins une partie du système immunitaire. Les évaluations actuelles de la prévalence des immunodéficiences primaires sont de un cas sur 1 200 patients. En Ontario, où l'omnipraticien moyen suit de 1 300 à 2 000 patients, on estime que deux de ces patients seront atteints d'une immunodéficience primaire. Puisque de nouvelles immunodéficiences primaires sont décrites à un taux exponentiel et que celles qui sont déjà décrites sont de mieux en mieux comprises, il est difficile pour les professionnels de la santé de demeurer à jour. Les lacunes sur le plan du savoir retardent le diagnostic et le traitement, ce qui accroît la morbidité et la mortalité. La présente analyse vise à fournir au dispensateur de soins de première ligne les outils nécessaires pour identifier les immunodéficiences primaires et contribuer à poser les diagnostics.

6.
Clin Exp Allergy ; 45(1): 249-54, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25207855

ABSTRACT

BACKGROUND: Studies suggest that siblings of children with peanut allergy (PNA) have a higher prevalence of PNA than the general population. OBJECTIVES: The Canadian Peanut Allergy Registry was used to assess the percentage of siblings of registered index PNA children who were 1) never exposed to peanut or 2) reportedly diagnosed with PNA by a physician without either a history of allergic reaction or a confirmatory testing. Sociodemographic and clinical factors that may be associated with either outcome were evaluated. METHODS: Parents completed a questionnaire on siblings' sociodemographic characteristics, exposure and reaction to peanut, confirmatory tests performed and whether PNA had been diagnosed. RESULTS: Of 932 Registry families, 748 families responded, representing 922 siblings. 13.6% of siblings had never been exposed to peanut, 70.4% (n = 88) of which were born after the index child. Almost 9% of siblings (80) were reported as PNA, but almost half of this group had no history of an allergic reaction to peanut, including five children who also had no testing to confirm PNA. Of these 5, 4 were born after PNA diagnosis in the index child. In a multivariate regression analysis for siblings at least 3 years old, those born after PNA diagnosis in the index child were more likely to have never been exposed to peanut. In a univariate analysis, siblings born after the diagnosis of PNA in the index child were more likely to be diagnosed with PNA without supportive history or confirmatory testing. CONCLUSIONS AND CLINICAL RELEVANCE: These data estimate that more than 10% of siblings of PNA patients will avoid peanut and that siblings born after the diagnosis of PNA in an index child are more likely to have never been exposed. Educational programs and guidelines that caution against unnecessary avoidance are required.


Subject(s)
Arachis , Peanut Hypersensitivity/diagnosis , Peanut Hypersensitivity/epidemiology , Registries , Siblings , Surveys and Questionnaires , Adolescent , Canada/epidemiology , Child , Female , Humans , Male
7.
Allergy ; 68(2): 131-41, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23157275

ABSTRACT

BACKGROUND: Chronic spontaneous urticaria (CSU) is one of the most costly allergic conditions challenging physicians as well as patients and their families. Despite evident lacunae in the understanding of the pathogenesis, at least some findings suggest that psychosocial factors likely contribute to the development and exacerbation of CSU. We aim to assess the contribution of psychological factors to CSU. METHODS: Systematic search of PubMed and OVID/Medline databases was conducted from 1 January 1935 to 1 January 2012. Studies selected include original research in English, Spanish and French exploring the association between CSU and psychosocial factors. Two investigators independently reviewed all titles and abstracts to identify potentially relevant articles and resolved discrepancies by repeated review and discussion and arbitration of a third reviewer. Quality of systematic reviews and meta-analyses was assessed using a measure based on the Newcastle-Ottawa Scale and psychological conditions of CSU patients. RESULTS: We identified 114 eligible studies spanning 77 years and featuring 17 reviews, 67 studies related to neither CSU nor psychosocial factors, and eight studies that provided either no prevalence estimates or insufficient sample size. Pooling effect sizes using random effects, analyses revealed that, despite large heterogeneity (I(2) of 97.60%), psychosocial factors had a prevalence of 46.09% (95% confidence interval, 44.01%, 48.08%). CONCLUSION: Future research needs to better establish the contribution of psychosocial factors to the pathogenesis and exacerbation of CSU, and explore the possible benefit of behavioural interventions to the development of new management strategies.


Subject(s)
Urticaria/epidemiology , Urticaria/psychology , Behavior Therapy , Case-Control Studies , Chronic Disease , Confidence Intervals , Cross-Sectional Studies , Disease Progression , Female , Humans , Male , Needs Assessment , Odds Ratio , Prevalence , Prognosis , Psychology , Quebec/epidemiology , Reference Values , Severity of Illness Index , Urticaria/physiopathology , Urticaria/therapy
8.
Allergy ; 68(12): 1605-9, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24410784

ABSTRACT

Prompt epinephrine administration is crucial in managing anaphylaxis, but epinephrine auto-injectors (EAIs) are underutilized by patients and their families. Children with peanut allergy were recruited from the Allergy Clinics at the Montreal Children's Hospital, food allergy advocacy organizations and organizations providing products to allergic individuals. Parents of children who had been prescribed an EAI were queried on whether they were fearful of using it and on factors that may contribute to fear. A majority of parents (672/1209 = 56%) expressed fear regarding the use of the EAI. Parents attributed the fear to hurting the child, using the EAI incorrectly or a bad outcome. Parents whose child had longer disease duration or a severe reaction and parents who were satisfied with the EAI training or found it easy to use were less likely to be afraid. Families may benefit from simulation training and more education on the recognition and management of anaphylaxis.


Subject(s)
Epinephrine/administration & dosage , Fear , Peanut Hypersensitivity/drug therapy , Peanut Hypersensitivity/psychology , Adolescent , Anaphylaxis/prevention & control , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Injections, Intramuscular , Male , Peanut Hypersensitivity/epidemiology , Risk Factors
9.
J Allergy (Cairo) ; 2012: 858306, 2012.
Article in English | MEDLINE | ID: mdl-22187574

ABSTRACT

Background. Studies suggest that the rising prevalence of food allergy during recent decades may have stabilized. Although genetics undoubtedly contribute to the emergence of food allergy, it is likely that other factors play a crucial role in mediating such short-term changes. Objective. To identify potential demographic predictors of food allergies. Methods. We performed a cross-Canada, random telephone survey. Criteria for food allergy were self-report of convincing symptoms and/or physician diagnosis of allergy. Multivariate logistic regressions were used to assess potential determinants. Results. Of 10,596 households surveyed in 2008/2009, 3666 responded, representing 9667 individuals. Peanut, tree nut, and sesame allergy were more common in children (odds ratio (OR) 2.24 (95% CI, 1.40, 3.59), 1.73 (95% CI, 1.11, 2.68), and 5.63 (95% CI, 1.39, 22.87), resp.) while fish and shellfish allergy were less common in children (OR 0.17 (95% CI, 0.04, 0.72) and 0.29 (95% CI, 0.14, 0.61)). Tree nut and shellfish allergy were less common in males (OR 0.55 (95% CI, 0.36, 0.83) and 0.63 (95% CI, 0.43, 0.91)). Shellfish allergy was more common in urban settings (OR 1.55 (95% CI, 1.04, 2.31)). There was a trend for most food allergies to be more prevalent in the more educated (tree nut OR 1.90 (95% CI, 1.18, 3.04)) and less prevalent in immigrants (shellfish OR 0.49 (95% CI, 0.26, 0.95)), but wide CIs preclude definitive conclusions for most foods. Conclusions. Our results reveal that in addition to age and sex, place of residence, socioeconomic status, and birth place may influence the development of food allergy.

10.
Allergy ; 66(1): 1-14, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20560905

ABSTRACT

Anaphylaxis is a clinical emergency, and recent reports suggest increased prevalence. A diverse set of primary genetic and environmental influences may confer susceptibility to anaphylactic reactions. Anaphylaxis presents diagnostic and therapeutic challenges. It often manifests with a broad array of symptoms and signs that might be similar to other diseases. The management of anaphylaxis consists of emergency treatment of acute episodes as well as preventive strategies to avoid recurrences. Treatment is complicated by its rapid onset and progression, presence of concurrent diseases or medications, and need for long-term allergen avoidance. Health care professionals must be able to recognize the signs of anaphylaxis, treat an episode promptly and appropriately, and provide preventive recommendations. Recognizing the gaps in our understanding and management of anaphylaxis may help identify promising targets for future treatment and prevention and areas that require further study.


Subject(s)
Anaphylaxis , Epinephrine/therapeutic use , Adolescent , Adult , Aged , Aged, 80 and over , Allergens/adverse effects , Allergens/immunology , Anaphylaxis/drug therapy , Anaphylaxis/epidemiology , Anaphylaxis/genetics , Anaphylaxis/physiopathology , Child , Genetic Predisposition to Disease , Humans , Middle Aged , Prevalence , Research/trends , Risk Factors , Young Adult
11.
Blood Cancer J ; 1(7): e31, 2011 Jul.
Article in English | MEDLINE | ID: mdl-22829187

ABSTRACT

Malignant cells are known to have increased glucose uptake and accelerated glucose metabolism. Using liquid chromatography and mass spectrometry, we found that treatment of acute lymphoblastic leukemia (ALL) cells with the glucocorticoid (GC) dexamethasone (Dex) resulted in profound inhibition of glycolysis. We thus demonstrate that Dex reduced glucose consumption, glucose utilization and glucose uptake by leukemic cells. Furthermore, Dex treatment decreased the levels of the plasma membrane-associated glucose transporter GLUT1, thus revealing the mechanism for the inhibition of glucose uptake. Inhibition of glucose uptake correlated with induction of cell death in ALL cell lines and in leukemic blasts from ALL patients cultured ex vivo. Addition of di-methyl succinate could partially overcome cell death induced by Dex in RS4;11 cells, thereby further supporting the notion that inhibition of glycolysis contributes to the induction of apoptosis. Finally, Dex killed RS4;11 cells significantly more efficiently when cultured in lower glucose concentrations suggesting that modulation of glucose levels might influence the effectiveness of GC treatment in ALL. In summary, our data show that GC treatment blocks glucose uptake by leukemic cells leading to inhibition of glycolysis and that these effects play an important role in the induction of cell death by these drugs.

13.
Eur J Pediatr ; 166(3): 269-72, 2007 Mar.
Article in English | MEDLINE | ID: mdl-16944239

ABSTRACT

Cochlear dysplasia is a rare congenital anomaly. However, early detection of this anomaly can prevent serious consequences. We describe three cases of cochlear dysplasia that presented with recurrent meningitis and cerebro-spinal fluid (CSF) leak in children in which early diagnosis prevented further complications.


Subject(s)
Cochlea/pathology , Cochlear Diseases/complications , Meningitis, Pneumococcal/complications , Child, Preschool , Cochlea/abnormalities , Cochlear Diseases/diagnosis , Female , Humans , Infant , Male , Meningitis, Pneumococcal/diagnosis , Meningitis, Pneumococcal/physiopathology
14.
Apoptosis ; 8(3): 263-8, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12766486

ABSTRACT

We have developed an apoptosis assay based on measurement of a neoepitope of cytokeratin-18 (CK18-Asp396) exposed after caspase-cleavage and detected by the monoclonal antibody M30. The total amount of caspase-cleaved CK18 which has accumulated in cells and tissue culture media during apoptosis is measured by ELISA. The sensitivity is sufficient for use in the 96-well format to allow high-through-put screening of drug libraries. We here describe strategies allowing classification of pro-apoptotic compounds according to their profiles of induction of apoptosis in the presence of pharmacological inhibitors. The time course of induction of CK18 cleavage can furthermore be used to distinguish structurally similar compounds. We propose that compounds that induce rapid CK18 cleavage have mechanisms of actions distinct from conventional genotoxic and microtubuli-targeting agents, and we present one example of an agent that induces almost immediate mitochondrial depolarization and cytochrome c release. Finally, CK18-Asp396 cleavage products are released from cells in tissue culture, and presumably from tumor cells in vivo. These products can be measured in sera from cancer patients. We present evidence suggesting that it will be possible to use the M30-ELISA assay for measuring chemotherapy-induced apoptosis in patient sera, opening possibilities for monitoring therapy.


Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Drug Evaluation, Preclinical/methods , Enzyme-Linked Immunosorbent Assay/methods , Neoplasms/drug therapy , Antibodies, Monoclonal , Antineoplastic Agents/classification , Apoptosis/physiology , Aspartic Acid/metabolism , Caspases/metabolism , Cell Line, Tumor , Cytochromes c/metabolism , Drug Evaluation, Preclinical/instrumentation , Enzyme Inhibitors/pharmacology , Enzyme-Linked Immunosorbent Assay/instrumentation , Epitopes/immunology , Humans , Keratins/blood , Keratins/immunology , Membrane Potentials/drug effects , Membrane Potentials/physiology , Mitochondria/drug effects , Mitochondria/metabolism , Neoplasm Recurrence, Local/blood , Neoplasms/blood , Peptide Fragments/blood , Predictive Value of Tests , Reproducibility of Results , Treatment Outcome
15.
Mol Cell Biol ; 21(11): 3684-91, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11340162

ABSTRACT

In a panel of four human melanoma cell lines, equitoxic doses of cisplatin induced the proapoptotic conformation of the Bcl-2 family protein Bak prior to the execution phase of apoptosis. Because cisplatin-induced modulation of the related Bax protein was seen in only one cell line, a degree of specificity in the signal to Bak is indicated. Little is known about upstream regulation of Bak activity. In this study, we examined whether the apoptosis-specific pathway mediated by a kinase fragment of MEKK1 (DeltaMEKK1) is involved in the observed Bak modulation. We report that expression of a kinase-inactive fragment of MEKK1 (dominant negative MEKK [dnMEKK]) efficiently blocked cisplatin-induced modulation of Bak and cytochrome c release and consequently also reduced DEVDase activation and nuclear fragmentation. Accordingly, expression of a kinase-active MEKK1 fragment (dominant positive MEKK) was sufficient to induce modulation of Bak in three cell lines and to induce apoptosis in two of these. dnMEKK did not block cisplatin-induced c-Jun N-terminal kinase (JNK) activation, in agreement with a specifically proapoptotic role for the DeltaMEKK1 pathway. Finally, we show that reduction of Bak expression by antisense Bak reduced cisplatin-induced loss of mitochondrial integrity and caspase cleavage activity in breast cancer cell lines. In summary, we have identified Bak as a cisplatin-regulated component downstream in a proapoptotic, JNK-independent DeltaMEKK1 pathway.


Subject(s)
Antineoplastic Agents/metabolism , Apoptosis , Cisplatin/metabolism , MAP Kinase Kinase Kinase 1 , Membrane Proteins/metabolism , Protein Serine-Threonine Kinases/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , Antineoplastic Agents/pharmacology , Cisplatin/pharmacology , Cytochrome c Group/metabolism , Enzyme Activation , Humans , Mitogen-Activated Protein Kinase 8 , Mitogen-Activated Protein Kinase 9 , Mitogen-Activated Protein Kinases/metabolism , Proto-Oncogene Proteins/metabolism , Tumor Cells, Cultured , bcl-2 Homologous Antagonist-Killer Protein , bcl-2-Associated X Protein
16.
Toxicol Appl Pharmacol ; 173(1): 56-64, 2001 May 15.
Article in English | MEDLINE | ID: mdl-11350215

ABSTRACT

We have previously shown that one of the most potent rodent hepatocarcinogens, perfluorooctanoic acid (PFOA), induces apoptosis in human HepG2 cells in a dose- and time-dependent manner. In this study we have investigated the involvement of reactive oxygen species (ROS), mitochondria, and caspase-9 in PFOA-induced apoptosis. Treatment with 200 and 400 microM PFOA was found to cause a dramatic increase in the cellular content of superoxide anions and hydrogen peroxide after 3 h. Measurement of the mitochondrial transmembrane potential (Delta Psi(m)) after PFOA treatment showed a dissipation of Delta Psi(m) at 3 h. Caspase-9 activation was seen at 5 h after treatment with 200 microM PFOA. In order to evaluate the importance of these events in PFOA-induced apoptosis, cells were cotreated with PFOA and N-acetylcysteine (NAC), a precursor of glutathione, or Cyclosporin A (CsA), an inhibitor of mitochondrial permeability transition pore (MPT pore). NAC reduced Delta Psi(m) dissipation, caspase 9 activation, and apoptosis, indicating a role for PFOA-induced ROS. In addition, CsA also reduced Delta Psi(m) dissipation, caspase 9 activation, and apoptosis, indicating a role for PFOA-induced opening of the MPT pore. In summary, we have delineated a ROS and mitochondria-mediated pathway for induction of apoptosis by PFOA.


Subject(s)
Apoptosis/drug effects , Caprylates/pharmacology , Carcinoma, Hepatocellular/pathology , Fluorocarbons/pharmacology , Liver Neoplasms/pathology , Mitochondria, Liver/physiology , Reactive Oxygen Species/metabolism , Acetylcysteine/pharmacology , Carcinogens/pharmacology , Caspase 9 , Caspases/metabolism , Cyclosporine/pharmacology , Dose-Response Relationship, Drug , Enzyme Activation/drug effects , Flow Cytometry , Humans , Hydrogen Peroxide/metabolism , Kinetics , Membrane Potentials , Superoxides/metabolism , Tumor Cells, Cultured
17.
Melanoma Res ; 11(1): 11-9, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11254111

ABSTRACT

The regulation of apoptosis is believed to be dependent on the balance of the activities of different intracellular signalling systems. Activation of the SAPK/JNK pathway is implied in pro-apoptotic signalling, while activation of the MEK1/ERK pathway may have a viability-promoting effect. We show here that treatment with the MEK1 inhibitor PD98059 sensitizes the human melanoma cell line C8161 to cisplatin-induced apoptosis. In these cells, cisplatin at 40 microM did not elicit significant cell death, whereas massive cell death was seen when cells were pretreated for 20 h with 40 microM PD98059 before the addition of cisplatin. Concomitant addition of PD98059 and cisplatin did not have any sensitizing effect, and PD98059 on its own did not induce apoptosis. However, in three other human melanoma cell lines PD98059 did not potentiate cisplatin-induced apoptosis. Instead, in one of these cell lines (AA), PD98059 protected against cisplatin-induced cytotoxicity. We conclude that blocking of the MEK1/ERK pathway may, in some instances, potentiate the cytotoxic effect of cisplatin on human melanoma cell lines, whereas in other instances it may have a protective effect. Thus it cannot be regarded as a general approach to sensitizing melanoma cells to drug-induced apoptosis.


Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Cisplatin/pharmacology , Enzyme Inhibitors/pharmacology , Flavonoids/pharmacology , Melanoma/drug therapy , Mitogen-Activated Protein Kinase Kinases/antagonists & inhibitors , Protein Serine-Threonine Kinases/antagonists & inhibitors , Blotting, Western , Caspase 3 , Caspases/metabolism , Cell Cycle/drug effects , Cell Survival/drug effects , DNA Fragmentation , Dose-Response Relationship, Drug , Drug Resistance, Neoplasm , Humans , MAP Kinase Kinase 1 , Mitogen-Activated Protein Kinase 8 , Mitogen-Activated Protein Kinases/metabolism , Phosphorylation , Time Factors , Tumor Cells, Cultured
18.
Electrophoresis ; 21(13): 2737-43, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10949153

ABSTRACT

Biochemical and genetic strategies have implied that aberrant signaling in the extracellular signal-regulated kinase (ERK)/mitogen-activated protein (MAP) kinase pathway contributes significantly to transformed phenotypes. Using PD98059, an inhibitor of the ERK-kinase MEK1, we have here assessed the effects of ERK inhibition on the pattern of protein expression in the metastatic human breast cancer cell line MDA-MB-231. At a concentration of inhibitor which did not significantly affect cell growth, PD98059 induced large changes in the expression of MDA-MB-231 polypeptides. The majority of these changes were due to decreased expression of low-abundance proteins. Decreases of more abundant proteins such as glutathione-S-transferase pi, hsp80 and hsp100 were also recorded. The levels of a few proteins increased, among them cytokeratin 8. We conclude that PD98059 treatment of MDA-MB-231 cells induces large changes in protein expression.


Subject(s)
Breast Neoplasms/enzymology , Enzyme Inhibitors/pharmacology , Flavonoids/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , MAP Kinase Signaling System/drug effects , Mitogen-Activated Protein Kinase 1/antagonists & inhibitors , Mitogen-Activated Protein Kinase Kinases/antagonists & inhibitors , Mitogen-Activated Protein Kinases/antagonists & inhibitors , Neoplasm Proteins/antagonists & inhibitors , Protein Serine-Threonine Kinases/antagonists & inhibitors , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cell Division/drug effects , Dose-Response Relationship, Drug , Electrophoresis, Gel, Two-Dimensional , Female , Gene Expression Profiling , Humans , MAP Kinase Kinase 1 , Mitogen-Activated Protein Kinase 1/physiology , Mitogen-Activated Protein Kinase 3 , Mitogen-Activated Protein Kinases/physiology , Neoplasm Metastasis , Neoplasm Proteins/physiology , Peptides/analysis , Phosphorylation/drug effects , Protein Processing, Post-Translational/drug effects , Subtraction Technique , Tumor Cells, Cultured/drug effects , Tumor Cells, Cultured/enzymology
19.
Apoptosis ; 5(4): 355-67, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11227217

ABSTRACT

Mutationally activated Ras is involved in tumor progression and likely also in drug resistance. Using survival, viability and apoptosis assays, we have here compared the cisplatin sensitivities of FR3T3 rat fibroblasts and a 12V-H-ras transformed subline (Ras2:3). Around 24 h after cisplatin treatment Ras2:3 cells showed higher apoptosis levels and lower viability than FR3T3. This increased sensitivity correlated with weaker cisplatin-induced activation of Jun N-terminal kinase (JNK). In contrast to apoptosis assays, colony formation assays showed that Ras2:3 were more resistant to cisplatin than were FR3T3. This was partly due to the increased cisplatin sensitivity of FR3T3 seeded at low densities, as required in colony formation assays. In addition, Ras2:3 cisplatin survivors had a higher relative proliferative capacity. Cell cycle analyses showed that FR3T3 cells initially responded with a dose-dependent G2 arrest, while Ras2:3 accumulated in S-phase. Experiments with an anti-apoptotic mutant of MEKK1 suggested that the apoptotic response of Ras2:3 cells is not specific to the S-phase fraction. In summary, the cisplatin response of ras-transformed fibroblasts is distinct from that of parental cells, in that they show increased apoptosis, a different cell cycle response and increased post-treatment proliferative capacity. The results illustrate the need to carefully consider methods and protocols for in vitro studies on chemotherapy sensitivity.


Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Cell Survival/drug effects , Cell Transformation, Neoplastic , Cisplatin/pharmacology , Genes, ras , MAP Kinase Kinase Kinase 1 , Animals , Cell Cycle/drug effects , Cell Line, Transformed , Cell Nucleus/metabolism , Dose-Response Relationship, Drug , Enzyme Activation , Fibroblasts , Flow Cytometry , Humans , Mitogen-Activated Protein Kinases/metabolism , Protein Serine-Threonine Kinases/metabolism , Rats , Tumor Stem Cell Assay
20.
Cell Mol Life Sci ; 55(3): 467-71, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10228560

ABSTRACT

Signalling via the protein kinase Raf-MEK-ERK pathway is of major importance for transformation by oncogenes. To identify genes affected by inhibition of this pathway, c-JUN transformed rat fibroblasts were treated with a MEK1 inhibitor (PD98059) and subjected to two-dimensional gel electrophoresis after cell lysis. Gene products with expression influenced by MEK1 inhibition were determined by mass spectrometry of fragments from in-gel tryptic digestions. The expression of pirin, a nuclear factor I-interacting protein, was lowered after inhibition of MEK1. Western blot analysis revealed increased expression of pirin in RAS and c-JUN transformed cells in the absence of PD98059. Inhibition of MEK1 also led to reduced expression of alpha-enolase, phosphoglycerate kinase, elongation factor 2 and heterogeneous nuclear ribonucleoprotein A3, the latter two being detected as truncated proteins. In contrast, the level of ornithine aminotransferase was increased. We conclude that inhibition of MEK1 results in major alterations of protein expression in c-JUN transformed cells, suggesting that this pathway is important for oncogene-induced phenotypic changes.


Subject(s)
Carrier Proteins/biosynthesis , Cell Transformation, Neoplastic/genetics , Fibroblasts/metabolism , Genes, jun , Genes, ras , Mitogen-Activated Protein Kinase Kinases , Mitogen-Activated Protein Kinases , Nuclear Proteins/biosynthesis , Protein Serine-Threonine Kinases/physiology , Protein-Tyrosine Kinases/physiology , Signal Transduction/genetics , Animals , Calcium-Calmodulin-Dependent Protein Kinases/physiology , Carrier Proteins/genetics , Cell Line, Transformed , Dioxygenases , Fibroblasts/drug effects , Flavonoids/pharmacology , Heterogeneous-Nuclear Ribonucleoproteins , MAP Kinase Kinase 1 , Mass Spectrometry , Mitogen-Activated Protein Kinase 1 , Mitogen-Activated Protein Kinase 3 , Nuclear Proteins/genetics , Ornithine-Oxo-Acid Transaminase/biosynthesis , Ornithine-Oxo-Acid Transaminase/genetics , Peptide Elongation Factor 2 , Peptide Elongation Factors/biosynthesis , Peptide Elongation Factors/genetics , Phosphoglycerate Kinase/biosynthesis , Phosphoglycerate Kinase/genetics , Phosphopyruvate Hydratase/biosynthesis , Phosphopyruvate Hydratase/genetics , Protein Serine-Threonine Kinases/antagonists & inhibitors , Protein-Tyrosine Kinases/antagonists & inhibitors , Proto-Oncogene Proteins c-raf/physiology , Rats , Ribonucleoproteins/biosynthesis , Ribonucleoproteins/genetics , Transfection
SELECTION OF CITATIONS
SEARCH DETAIL
...