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1.
J Cell Mol Med ; 20(5): 855-63, 2016 May.
Article in English | MEDLINE | ID: mdl-26859834

ABSTRACT

Cardiovascular disease (CVD) is a major cause of morbidity and mortality in rheumatoid arthritis (RA). There are limited experimental data on vascular involvement in arthritis models. To study the link between CVD and inflammation in RA, we developed a model of vascular dysfunction and articular inflammation by collagen-induced arthritis (CIA) in C57Bl/6 (B6) mice. We studied the expression of vascular inflammatory markers in CIA with and without concomitant hyperlipidic diet (HD). Collagen-induced arthritis was induced with intradermal injection of chicken type-II collagen followed by a boost 21 days later. Mice with and without CIA were fed a standard diet or an HD for 12 weeks starting from the day of the boost. Arthritis severity was evaluated with a validated clinical score. Aortic mRNA levels of vascular cell adhesion molecule-1 (VCAM-1), inducible nitric oxide synthase (iNOS) and interleukin-17 were analysed by quantitative RT-PCR. Vascular cell adhesion molecule-1 localization in the aortic sinus was determined by immunohistochemistry. Atherosclerotic plaque presence was assessed in aortas. Collagen-induced arthritis was associated with increased expression of VCAM-1, independent of diet. VCAM-1 overexpression was detectable as early as 4 weeks after collagen immunization and persisted after 15 weeks. The HD induced atheroma plaque formation and aortic iNOS expression regardless of CIA. Concomitant CIA and HD had no additive effect on atheroma or VCAM-1 or iNOS expression. CIA and an HD diet induced a distinct and independent expression of large-vessel inflammation markers in B6 mice. This model may be relevant for the study of CVD in RA.


Subject(s)
Aorta/immunology , Arthritis, Experimental/immunology , Atherosclerosis/immunology , Plaque, Atherosclerotic/immunology , Vascular Cell Adhesion Molecule-1/immunology , Animals , Aorta/pathology , Arthritis, Experimental/chemically induced , Arthritis, Experimental/genetics , Arthritis, Experimental/pathology , Arthritis, Rheumatoid/genetics , Arthritis, Rheumatoid/immunology , Arthritis, Rheumatoid/pathology , Atherosclerosis/etiology , Atherosclerosis/genetics , Atherosclerosis/pathology , Biomarkers/metabolism , Collagen/administration & dosage , Diet, High-Fat/adverse effects , Gene Expression , Humans , Inflammation , Interleukin-17/genetics , Interleukin-17/immunology , Male , Mice , Mice, Inbred C57BL , Nitric Oxide Synthase Type II/genetics , Nitric Oxide Synthase Type II/immunology , Plaque, Atherosclerotic/etiology , Plaque, Atherosclerotic/genetics , Plaque, Atherosclerotic/pathology , RNA, Messenger/genetics , RNA, Messenger/immunology , Severity of Illness Index , Vascular Cell Adhesion Molecule-1/genetics
2.
J Cell Mol Med ; 20(10): 1956-65, 2016 10.
Article in English | MEDLINE | ID: mdl-27464833

ABSTRACT

The SN 1 alkylating agents activate the mismatch repair system leading to delayed G2 /M cell cycle arrest and DNA repair with subsequent survival or cell death. STAT1, an anti-proliferative and pro-apoptotic transcription factor is known to potentiate p53 and to affect DNA-damage cellular response. We studied whether STAT1 may modulate cell fate following activation of the mismatch repair system upon exposure to the alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Using STAT1-proficient or -deficient cell lines, we found that STAT1 is required for: (i) reduction in the extent of DNA lesions, (ii) rapid phosphorylation of T68-CHK2 and of S15-p53, (iii) progression through the G2 /M checkpoint and (iv) long-term survival following treatment with MNNG. Presence of STAT1 is critical for the formation of a p53-DNA complex comprising: STAT1, c-Abl and MLH1 following exposure to MNNG. Importantly, presence of STAT1 allows recruitment of c-Abl to p53-DNA complex and links c-Abl tyrosine kinase activity to MNNG-toxicity. Thus, our data highlight the important modulatory role of STAT1 in the signalling pathway activated by the mismatch repair system. This ability of STAT1 to favour resistance to MNNG indicates the targeting of STAT1 pathway as a therapeutic option for enhancing the efficacy of SN1 alkylating agent-based chemotherapy.


Subject(s)
Alkylating Agents/pharmacology , Methylnitronitrosoguanidine/pharmacology , STAT1 Transcription Factor/deficiency , Cell Cycle/drug effects , Cell Death/drug effects , Cell Line, Tumor , Cell Survival/drug effects , Checkpoint Kinase 2/metabolism , Cytoprotection/drug effects , DNA/metabolism , DNA Breaks, Double-Stranded/drug effects , Histones/metabolism , Humans , Imatinib Mesylate/pharmacology , Protein Isoforms/metabolism , Proto-Oncogene Proteins c-abl/metabolism , STAT1 Transcription Factor/metabolism , Tumor Suppressor Protein p53/metabolism
3.
Int J Mol Sci ; 14(10): 20508-42, 2013 Oct 14.
Article in English | MEDLINE | ID: mdl-24129182

ABSTRACT

Abnormalities in melatonin physiology may be involved or closely linked to the pathophysiology and behavioral expression of autistic disorder, given its role in neurodevelopment and reports of sleep-wake rhythm disturbances, decreased nocturnal melatonin production, and beneficial therapeutic effects of melatonin in individuals with autism. In addition, melatonin, as a pineal gland hormone produced from serotonin, is of special interest in autistic disorder given reported alterations in central and peripheral serotonin neurobiology. More specifically, the role of melatonin in the ontogenetic establishment of circadian rhythms and the synchronization of peripheral oscillators opens interesting perspectives to ascertain better the mechanisms underlying the significant relationship found between lower nocturnal melatonin excretion and increased severity of autistic social communication impairments, especially for verbal communication and social imitative play. In this article, first we review the studies on melatonin levels and the treatment studies of melatonin in autistic disorder. Then, we discuss the relationships between melatonin and autistic behavioral impairments with regard to social communication (verbal and non-verbal communication, social interaction), and repetitive behaviors or interests with difficulties adapting to change. In conclusion, we emphasize that randomized clinical trials in autism spectrum disorders are warranted to establish potential therapeutic efficacy of melatonin for social communication impairments and stereotyped behaviors or interests.


Subject(s)
Child Development Disorders, Pervasive/metabolism , Child Development Disorders, Pervasive/therapy , Melatonin/metabolism , Animals , Child Development Disorders, Pervasive/physiopathology , Communication Disorders/metabolism , Communication Disorders/physiopathology , Communication Disorders/therapy , Humans
4.
Diagnostics (Basel) ; 13(5)2023 Mar 01.
Article in English | MEDLINE | ID: mdl-36900081

ABSTRACT

Next generation sequencing analysis is crucial for therapeutic decision in various solid tumor contexts. The sequencing method must remain accurate and robust throughout the instrument lifespan allowing the biological validation of patients' results. This study aims to evaluate the long-term sequencing performances of the Oncomine Focus assay kit allowing theranostic DNA and RNA variants detection on the Ion S5XL instrument. We evaluated the sequencing performances of 73 consecutive chips over a 21-month period and detailed the sequencing data obtained from both quality controls and clinical samples. The metrics describing sequencing quality remained stable throughout the study. We showed that an average of 11 × 106 (±0.3 × 106) reads were obtained using a 520 chip leading to an average of 6.0 × 105 (±2.6 × 105) mapped reads per sample. Of 400 consecutive samples, 95.8 ± 16% of amplicons reached the depth threshold of 500X. Slight modifications of the bioinformatics workflow improved DNA analytical sensitivity and allowed the systematic detection of expected SNV, indel, CNV, and RNA alterations in quality controls samples. The low inter-run variability of DNA and RNA-even at low variant allelic fraction, amplification factor, or reads counts-indicated that our method was adapted to clinical practice. The analysis of 429 clinical DNA samples indicated that the modified bioinformatics workflow allowed detection of 353 DNA variants and 88 gene amplifications. RNA analysis of 55 clinical samples revealed 7 alterations. This is the first study showing the long-term robustness of the Oncomine Focus assay in clinical routine practice.

5.
Blood ; 116(22): 4588-90, 2010 Nov 25.
Article in English | MEDLINE | ID: mdl-20739656

ABSTRACT

Recent developments in the management of chronic lymphocytic leukemia (CLL) patients have made necessary the availability of dependable prognostic factors. We have developed a prognostic index derived from the multivariate analysis of 339 stage A patients at diagnosis, exhaustively studied for classical and recent predictive markers. Only 4 biologic parameters were found to be independent predictors of progression-free survival (PFS): serum thymidine kinase (sTK), lymphocytosis, ß2-microglobulin, and CD38 expression. Two groups were distinguishable: cases with no or 1 risk factor (among whom 85% did not progress after 7 years), and cases with 2 or more factors showing a median PFS of 20 months. Finally, we propose an easy, fast, cost-effective strategy for a trustworthy prognostication in stage A patients, who currently represent more than 80% of the CLL population, allowing physicians to adapt follow-up individually.


Subject(s)
Leukemia, Lymphocytic, Chronic, B-Cell/diagnosis , Disease-Free Survival , Humans , Multivariate Analysis , Prognosis
6.
Clin Res Hepatol Gastroenterol ; 45(4): 101691, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33852952

ABSTRACT

BACKGROUND: The prevalence and prognosis association of microsatellite instability (MSI) in oesogastric junction and gastric adenocarcinoma (OGC) have been reported with conflicting results. METHODS: Patients with OGC from 2010 to 2015 were enrolled in this retrospective multicenter study. MSI was determined by genotyping. MLH1 promoter methylation and BRAFV600E mutation were screened in the MSI tumors. RESULTS: Among 315 tumors analyzed, 39 (12.4%) were of the MSI phenotype. Compared to MSS tumors, MSI tumors were more frequent in patients >70 years (17% vs 9%, p=0.048) and in gastric antral primary (20% versus 5% in junction tumor and 12% in fundus tumor. Among 29 MSI tumors analyzed, 28 had a loss of MLH1 protein expression and 27 had MLH1 promotor hypermethylation. None had a BRAF V600E mutation. The 4-year cumulative incidence of recurrence for patients with resected tumor was significantly lower in dMMR tumors versus pMMR tumors (17% versus 47%, p=0.01). For the patients with unresectable tumor the median overall survival was 11 months in MSS group and 14 months in MSI group (p=0.24). CONCLUSION: MSI prevalence in OGC was 12.4%, associated with antral localization and advanced age. Patients with MSI tumors had a lower cumulative incidence of recurrence after surgery. MSI phenotype was mainly associated with loss of MLH1 protein expression, MLH1 promotor hypermethylation and had no BRAFV600E mutation.


Subject(s)
Adenocarcinoma , Microsatellite Instability , Stomach Neoplasms , Adenocarcinoma/genetics , Humans , MutL Protein Homolog 1/genetics , Prevalence , Prognosis , Retrospective Studies , Stomach Neoplasms/genetics
7.
Anticancer Res ; 29(5): 1615-20, 2009 May.
Article in English | MEDLINE | ID: mdl-19443375

ABSTRACT

BACKGROUND: Microsatellite Instability (MSI) status is a good prognostic factor for colorectal cancer (CRC) but its predictive value for chemosensitivity remains controversial. A previous meta-analysis (MA) in the adjuvant setting showed that MSI-high (H) status did not predict the efficacy of chemotherapy. The predictive value of MSI status on the effect of metastatic chemotherapy was investigated by MA. PATIENTS AND METHODS: Studies were identified by electronic search through PubMed, Embase and ASCO proceedings online databases, using several key words (colorectal cancer, chemotherapy, microsatellite instability). For each study, the ratio of response rate (RR), complete (CR) and partial response (PR) divided by stable disease and progression was calculated. From 190 articles and 100 abstracts, only eight independent studies were selected. The data were analysed with a random-effect model (due to heterogeneity between studies) using EasyMA software. Statistical calculations were performed on six studies representing 964 patients (mean age 63 years; 91 MSI-H; 873 microsatellite stable (MSS) tumours). A total of 287 patients received 5-fluorouracil (5FU)-based chemotherapy, whereas 678 patients received combinations of 5FU or capecitabine with oxaliplatin and/or irinotecan. RESULTS: No benefit of metastatic chemotherapy in terms of RR for MSI-H patients compared with MSS patients was found. The global hazard ratio (HR) for RR was 0.82 (95% confidence interval, CI: 0.95; 0.65-1.03; p=0.09). CONCLUSION: MSI status does not predict the effect of chemotherapy which is similar in MSI-H and MSS metastatic CRC tumours.


Subject(s)
Antineoplastic Agents/therapeutic use , Colorectal Neoplasms/genetics , Genomic Instability , Microsatellite Repeats/genetics , Neoplasm Metastasis , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/pathology , Humans , Middle Aged
8.
Eur J Gastroenterol Hepatol ; 30(3): 302-309, 2018 03.
Article in English | MEDLINE | ID: mdl-29271782

ABSTRACT

BACKGROUND: A few direct antiviral agents have been studied in difficult-to-treat patients infected by hepatitis C virus (HCV) genotype 4 (GT4). The efficacy of daclatasvir (DCV), asunaprevir (ASV), pegylated interferon and ribavirin (Peg-IFN/RBV) association was investigated in these patients. PATIENTS AND METHODS: This open-label, single-arm, phase 2 study was conducted in HCV GT4 patients who were null or partial responders to Peg-IFN/RBV. Patients received 24 weeks of DCV (60 mg, once daily), ASV (100 mg, twice daily) and Peg-IFN/RBV. The primary endpoint was sustained virologic response at post-treatment week 12 [sustained virologic response (SVR)12]. RESULTS: Sixty patients were included; 45 (75%) were previous null responders and 27 (45%) had cirrhosis. The most frequent subtypes were GT4a (48%) and GT4d (27%) with 25% of the patients being infected with other subtypes such as 4c, 4r, 4f, 4k, 4j and 4q. The global SVR12 was 95% (90% confidence interval: 90.4-99.6) and 96.3% (90% confidence interval: 87.5-99.5) in cirrhotic patients. All patients achieving SVR12 also achieved SVR24. Previous Peg-IFN/RBV response, IL28b genotype, cirrhosis status or GT4 subtypes did not influence SVR12 rates. Serious adverse events occurred in 13% of the patients, four being cirrhotic and four noncirrhotic. Three (5%) patients stopped HCV therapy prematurely: one because of virologic breakthrough and two because of serious adverse events. Grade 3/4 laboratory abnormalities included leukopenia (33%), neutropenia (27%), thrombocytopenia (4%) and transaminases increase (2%). CONCLUSION: Association of DCV plus ASV and peg-IFN/RBV for 24 weeks demonstrated a high rate of SVR12 in HCV GT4-infected prior nonresponders, independently of the cirrhotic status or the GT4 subtype. The safety profile was acceptable, even in cirrhotic patients.


Subject(s)
Antiviral Agents/therapeutic use , Hepatitis C, Chronic/drug therapy , Imidazoles/therapeutic use , Adult , Antiviral Agents/adverse effects , Carbamates , Drug Therapy, Combination , Female , Genotype , Hepacivirus/classification , Hepacivirus/genetics , Hepacivirus/isolation & purification , Hepatitis C, Chronic/complications , Hepatitis C, Chronic/virology , Humans , Imidazoles/adverse effects , Interferon alpha-2 , Interferon-alpha/adverse effects , Interferon-alpha/therapeutic use , Isoquinolines/adverse effects , Isoquinolines/therapeutic use , Liver Cirrhosis/virology , Male , Middle Aged , Pilot Projects , Pyrrolidines , RNA, Viral/blood , Recombinant Proteins/adverse effects , Recombinant Proteins/therapeutic use , Ribavirin/adverse effects , Ribavirin/therapeutic use , Sulfonamides/adverse effects , Sulfonamides/therapeutic use , Sustained Virologic Response , Treatment Failure , Treatment Outcome , Valine/analogs & derivatives , Viral Load/drug effects
9.
J Geriatr Oncol ; 5(4): 384-8, 2014 Oct 01.
Article in English | MEDLINE | ID: mdl-25176643

ABSTRACT

AIMS: Colorectal cancer (CRC) occurs mostly in the elderly. However, the biology of CRC in elderly has been poorly studied. This study examined the prevalence of deficient mismatch repair phenotype (dMMR) and BRAF mutations according to age. PATIENTS AND METHODS: MMR phenotype was prospectively determined by molecular analysis in patients of all ages undergoing surgery for CRC. BRAF V600E mutation status was analysed in a subset of dMMR tumours. RESULTS: A total of 754 patients who underwent surgery between 2005 and 2008 were included in the study. Amongst them, 272 (36%) were ≥75years old. The proportion of women <75 was 38% and that ≥75 was 53% (p<0.0001). The prevalence of dMMR was 19.4% in patients ≥75 and 10.7% in patients <75 (p=0.0017). For patients ≥75, the prevalence of dMMR was significantly higher in women than in men (27% vs 10.2%, respectively; p=0.003) but was similar in women and men <75 (12.5% vs 9.7%, respectively; p=0.4). We examined BRAF mutation status in 80 patients with dMMR tumours. The V600E BRAF mutation was significantly more frequent in patients ≥75 than in patients <75 (72.2% vs 11.4%, respectively; p<0.001). In patients ≥75, there was no difference in the prevalence of the BRAF V600E mutation according to sex (78% in women and 70% in men, p=0.9). CONCLUSIONS: The prevalence of dMMR in CRC is high in patients over 75. In elderly patients, dMMR tumours are significantly more frequent in women than in men. The BRAF mutation is frequent in elderly patients with CRC.


Subject(s)
Colorectal Neoplasms/genetics , DNA Mismatch Repair/genetics , Geriatric Assessment/methods , Mutation/genetics , Proto-Oncogene Proteins B-raf/genetics , Aged , Aged, 80 and over , Female , Geriatric Assessment/statistics & numerical data , Humans , Male , Phenotype , Prevalence , Prospective Studies , Sex Factors , Survival Analysis
10.
Dig Liver Dis ; 45(3): 245-50, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23102497

ABSTRACT

OBJECTIVE: About 15% of colorectal adenocarcinomas have a deficient DNA mismatch repair phenotype. The frequency of deficient DNA mismatch repair tumours increases with age due to the hypermethylation of hMLH1 promoter. The study aimed to determine the prognostic value of deficient DNA mismatch repair phenotype in elderly patients. DESIGN: Mismatch repair phenotype was retrospectively determined by molecular analysis in consecutive resected colorectal adenocarcinoma specimens from patients over 75 years of age from 4 Oncology centres. RESULTS: 231 patients (median age: 81, range: 75-100) were enrolled from 2005 to 2008. Mean prevalence of deficient DNA mismatch repair phenotype was 22.5%, and 36% for patients over 85 years. Deficient DNA mismatch repair status was significantly associated with older age, female sex, proximal colon primary and high grade tumour. For stage II tumours no deficient DNA mismatch repair tumours had a recurrence at end of follow-up compared to 17% for tumours with proficient phenotype. The proficient phenotype status was significantly associated with worse age-adjusted overall survival [HR 2.60; 95% CI 1.05-6.44; p=0.039]. For stage III tumours a trend for less recurrence was observed for deficient DNA mismatch repair phenotype (16%) compared to proficient phenotype (36%). CONCLUSION: deficient DNA mismatch repair phenotype is a prognostic factor in stage II colorectal tumour in elderly patients. Our results suggest that mismatch repair phenotype should be taken in consideration for adjuvant chemotherapy decision in elderly patients.


Subject(s)
Adenocarcinoma/genetics , Colorectal Neoplasms/genetics , DNA Mismatch Repair/physiology , Microsatellite Instability , Age Factors , Aged , Aged, 80 and over , DNA Methylation , DNA Mismatch Repair/genetics , Disease-Free Survival , Female , Humans , Male , Phenotype , Prognosis , Retrospective Studies
12.
Target Oncol ; 4(1): 57-62, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19343302

ABSTRACT

Microsatellite instability (MSI) status is a good prognostic factor for colorectal cancer (CRC), but its predictive value for chemosensitivity remains controversial. We recently performed a meta-analysis (MA) in adjuvant setting showing that MSI high (MSI-H) status did not predict the efficacy of chemotherapy. Studies were identified by electronic search through PubMed, Embase and ASCO proceedings online databases, using several keywords (colorectal cancer, chemotherapy, microsatellite instability). For each study, we calculated the ratio of response rate, complete and partial responses divided by stable disease and progression. Our MA dealt with the predictive value of MSI status on the effect of metastatic chemotherapy using various combinations of 5FU, oxaliplatin or CPT11. From 159 articles and 76 abstracts, we selected only seven independent studies. Data were analysed with a random-effect model (due to heterogeneity between studies) using EasyMA software. Statistical calculations were performed on five studies representing 860 patients (mean age 63 years; 87 MSI-H; 733 microsatellite stable [MSS] tumors). A total of 287 patients received 5FU-based chemotherapy, whereas 574 patients received combinations of 5FU or capecitabine with oxaliplatin and/or irinotecan. Our MA found no benefit of metastatic chemotherapy in terms of response rate for MSI-H patients compared with MSS patients. The global hazard ratio for response rate was 0.83 (95% confidence interval: 0.95; 0.65-1.05; p = 0.11). In conclusion, MSI status did not predict the effect of chemotherapy for metastatic CRC. Metastatic chemotherapy had a similar effect on both MSI-H or on MSS tumors.


Subject(s)
Biomarkers, Tumor/genetics , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Microsatellite Instability , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Capecitabine , Clinical Trials as Topic , Colorectal Neoplasms/diagnosis , Colorectal Neoplasms/therapy , DNA Mutational Analysis , Databases, Bibliographic , Deoxycytidine/administration & dosage , Deoxycytidine/analogs & derivatives , Fluorouracil/administration & dosage , Fluorouracil/analogs & derivatives , Humans , Neoplasm Metastasis , Organoplatinum Compounds/administration & dosage , Oxaliplatin , Predictive Value of Tests , Prognosis , Treatment Outcome
13.
Eur J Cancer ; 45(10): 1890-6, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19427194

ABSTRACT

BACKGROUND: Microsatellite instability (MSI) status in predicting the efficacy of adjuvant chemotherapy in colorectal cancer remains controversial. MATERIALS AND METHODS: Studies were identified through PubMed, Embase and ASCO proceedings with a combination of keywords (colorectal cancer, chemotherapy and MSI). RESULTS: A MA was performed for treated and non-treated MSI population on seven studies. Statistical calculations were performed on 7 studies representing 3690 patients; mean age: 65.5 years; 810 stage II and 2444 stage III (75%). MSI-high (MSI-H) was found in 454 patients (14% of the global population), and microsatellite stable (MSS) in 2871. A total of 1444 patients received 5-fluorouracil (5FU)-based chemotherapy, whereas 1518 patients did not. For MSI-H patients, there was no statistically significant difference for RFS whether or not they received chemotherapy (5 studies); HR RFS: 0.96 (95% confidence interval (CI): 0.62-1.49); HR OS (6 studies): 0.70 (95% CI: 0.44-1.09; p=0.12). Elsewhere, we found a significant interaction between MSI status (MSI-H or MSS) and therapeutic status suggesting a lesser benefit for MSI-H than for MSS patients (HR interaction RFS: 0.77 (95% CI: 0.67-0.87)). CONCLUSION: We found similar RFS for treated and untreated MSI-H patients, showing that MSI-H status, in addition to being a good prognostic factor is also a predictive factor of non response.


Subject(s)
Antineoplastic Agents/therapeutic use , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Microsatellite Instability , Aged , Chemotherapy, Adjuvant , Colorectal Neoplasms/pathology , Female , Humans , Male , Middle Aged , Neoplasm Staging , Prognosis , Survival Analysis , Treatment Outcome
14.
J Virol ; 79(8): 4936-43, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15795279

ABSTRACT

Constitutive activation of signal transducer and activator of transcription 1 (STAT1) is a distinctive feature of Epstein-Barr virus (EBV)-immortalized B cells (lymphoblastoid cell lines [LCLs]). The expression of STAT1 in these cells is modulated by the latent membrane protein 1 (LMP1), but the mechanism of STAT1 activation has remained unclear. We demonstrate that the tyrosine phosphorylation of STAT1 in LCLs results from an indirect pathway encompassing an NF-kappaB-dependent secretion of interferons (IFNs). The cell culture supernatant of LCLs induced tyrosine phosphorylation of STAT1 in cells with no constitutively activated STAT1. Moreover, removal of supernatant from LCLs was sufficient to decrease the phosphorylation of STAT1. Inhibition of NF-kappaB activity by different pharmacological inhibitors (i.e., parthenolide, MG132 and BAY 11-7082) and by overexpressed mutated IkappaBalpha prevented the activation of STAT1. To identify the factors involved, we performed macroarray cDNA profiling with or without inhibition of NF-kappaB. The expression of several cytokines was NF-kappaB dependent among those alpha and gamma IFNs (IFN-alpha and IFN-gamma), known activators of STAT1. By real-time PCR and enzyme-linked immunosorbent assay we show that IFN-alpha and IFN-gamma are expressed and released by LCLs in an NF-kappaB-dependent manner. Finally, the blocking of the IFN-alpha and IFN-gamma by neutralizing antibodies led to the complete inhibition of tyrosine phosphorylation of STAT1. Taken together, our results clearly show that LMP1-induced tyrosine phosphorylation of STAT1 is almost exclusively due to the NF-kappaB-dependent secretion of IFNs. Whether this response, which is usually considered to be antiviral, is in fact required for the persistence of the virus remains to be elucidated.


Subject(s)
B-Lymphocytes/immunology , DNA-Binding Proteins/metabolism , Herpesvirus 4, Human/immunology , NF-kappa B/immunology , Trans-Activators/metabolism , Viral Matrix Proteins/physiology , B-Lymphocytes/virology , Burkitt Lymphoma , Cell Line , Cell Line, Tumor , Cell Transformation, Viral , Cytokines/genetics , DNA-Binding Proteins/genetics , Genes, Reporter , Humans , Luciferases/genetics , Phosphorylation , Reverse Transcriptase Polymerase Chain Reaction , STAT1 Transcription Factor , Trans-Activators/genetics , Transfection
15.
J Pediatr Hematol Oncol ; 27(8): 416-9, 2005 Aug.
Article in English | MEDLINE | ID: mdl-16096522

ABSTRACT

Congenital dyserythropoietic anemia type I (CDA I) is a rare disorder of erythropoiesis. The objective of this study was to describe the clinical and laboratory manifestations, the diagnosis procedure, the therapeutic approaches and outcome in CDA I. The 12 patients included belong to the retrospective French Multicenter Study. Clinical and biologic data were compiled. Biologic tests included light and, in some cases, electron microscopy, ektacytometry, and red cell membrane protein electrophoresis. Neonatal manifestations (anemia, early jaundice, and/or splenomegaly) and bone abnormalities were present in 11 of the 12 and 6 of the 12 patients, respectively. CDA I was initially misdiagnosed in four children. By the time of diagnosis, anemia with reticulocytosis lower than expected in a hemolytic anemia was present in all patients. Bone marrow electron microscopy examination revealed characteristic findings in all nine children. Red cell membrane protein 4.1 was reduced in all five children. At least one transfusion was required in 11 of the 12 children. Interferon alpha2 corrected anemia in the three children who received monthly transfusions. CDA I is commonly misdiagnosed in children. It should be sought in patients with unexplained chronic anemia, especially when associated with neonatal manifestations, jaundice, splenomegaly, subnormal or low reticulocytosis, and congenital bone malformations.


Subject(s)
Anemia, Dyserythropoietic, Congenital/pathology , Anemia/etiology , Adolescent , Adult , Anemia, Dyserythropoietic, Congenital/complications , Anemia, Dyserythropoietic, Congenital/diagnosis , Anemia, Dyserythropoietic, Congenital/therapy , Bone Diseases/etiology , Child , Child, Preschool , Chronic Disease , Cohort Studies , Diagnosis, Differential , Female , France , Humans , Infant , Jaundice/etiology , Male , Microscopy, Electron , Splenomegaly/etiology
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