References of "Dehan, Pierre"
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See detailExpression of type 2 orexin receptor in human endometrium and its epigenetic silencing in endometrial cancer.
Dehan, Pierre ULg; Canon, C.; Trooskens, G. et al

in Journal of Clinical Endocrinology and Metabolism (2013), 98(4), 1549-57

CONTEXT: Orexins A and B are neuropeptides that bind and activate 2 types of receptors. In addition to direct action in the brain, the orexinergic system has broader implications in peripheral organs, and ... [more ▼]

CONTEXT: Orexins A and B are neuropeptides that bind and activate 2 types of receptors. In addition to direct action in the brain, the orexinergic system has broader implications in peripheral organs, and it has been proposed to have a role in the induction of apoptosis. There are very few data on the endometrium. OBJECTIVE: The expression and epigenetic regulation of type 2 orexin receptor (OX2R) was investigated in the human endometrium as well as in endometrial endometrioid carcinoma (EEC). METHODS: OX2R localization was studied by immunohistochemistry in normal endometrium (n = 24) and in EEC (n = 32). The DNA methylation status of a CpG island located in the first exon of OX2R was analyzed by bisulfite sequencing in normal (n = 18), EEC (n = 34), and 3 endometrial cell lines. On the latter, mRNA expression and Western blotting as well as in vitro induction with orexin were performed. RESULTS: Expression of the OX2R protein was detected in normal endometrial epithelia, whereas it was frequently lacking in EEC. This loss was associated with hypermethylation of OX2R in EEC in comparison with normal endometrium (median CpG methylation percentages of 48.85% and 5.85%, respectively). In cell lines, hypermethylation correlated with weak OX2R expression. Additionally, in vitro treatment of the 3 EEC cell lines with orexins A and B did not result in proliferation change CONCLUSIONS: Altogether our data provide evidence for the epigenetic silencing of OX2R in EEC. The implication of the OX2R loss in tumoral progression remains to be elucidated. [less ▲]

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See detailLe role de la genetique et de l'environnement dans le developpement de l'endometriose.
Ballester, M.; Dehan, Pierre ULg; BELIARD, Aude ULg et al

in Revue Médicale de Liège (2012), 67(5-6), 374-80

Endometriosis is usually described as a complex multifactorial disease involving dysregulation of estrogen metabolism, inflammatory and immunological mechanisms. Recently, many authors have questioned the ... [more ▼]

Endometriosis is usually described as a complex multifactorial disease involving dysregulation of estrogen metabolism, inflammatory and immunological mechanisms. Recently, many authors have questioned the environmental pollution and toxins in the formation and development of endometriotic lesions. Therefore, while dioxins and PCBs have been implicated, insufficient data are available until now to confirm this theory. Endometriosis has also been considered as a genetic disease. Indeed, early familial aggregation and twin studies noted a higher risk of endometriosis among relatives. However, demonstration of a genetic component in the pathogenesis of such a multifactorial disease is quite difficult due to many limitations such as ethnic differences, involvement of environmental factors and size of needed patients cohorts. Over the last decade, the epigenetic approach (DNA methylation, histones modifications and microRNA) has allowed to consider many new perspectives. Indeed, dysregulation (hyper- or hypomethylation) of many genes has already been highlighted. This method of analysis is the subject of numerous studies in order to develop diagnostic, prognostic and therapeutic tools for this disease which is becoming a real public health problem. [less ▲]

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See detailCurrent concepts in the pathology and epigenetics of endometrial carcinoma.
Arafa, Mohammad; Somja, Joan ULg; Dehan, Pierre ULg et al

in Pathology (2010), 42(7), 613-7

In the Western world, endometrial carcinoma is the most common malignant tumour of the female genital tract and is the fourth most common cancer in women. Two different clinicopathological subtypes are ... [more ▼]

In the Western world, endometrial carcinoma is the most common malignant tumour of the female genital tract and is the fourth most common cancer in women. Two different clinicopathological subtypes are recognised: the oestrogen-related (type I, endometrioid) and the non-oestrogen related (type II, non-endometrioid). This article reviews the epidemiology, risk factors, genetic alterations during endometrial carcinogenesis, features of tumours and precursors and early detection of the disease. Insights into the epigenetic alterations, with emphasis on DNA methylation during endometrial carcinogenesis, and their diagnostic value are also provided. [less ▲]

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See detailDNA methylation and cancer diagnosis: new methods and applications.
Dehan, Pierre ULg; Kustermans, Gaëlle ULg; Guénin, Samuel ULg et al

in Expert Review of Molecular Diagnostics (2009), 9(7), 651-7

Methylation of cytosines in cytosine-guanine (CpG) dinucleotides is one of the most important epigenetic alterations in animals. The presence of methylcytosine in the promoter of specific genes has ... [more ▼]

Methylation of cytosines in cytosine-guanine (CpG) dinucleotides is one of the most important epigenetic alterations in animals. The presence of methylcytosine in the promoter of specific genes has profound consequences on local chromatin structure and on the regulation of gene expression. Changes in DNA methylation play a central role in carcinogenesis. Hypermethylation and consecutive transcriptional silencing of tumor-suppressor genes has been documented in numerous cancers. The identification of target genes silenced by this modification has a great impact on diagnosis, classification, definition of risk groups and prognosis of cancer patients. Here we outline genome-wide techniques aiming at the identification of relevant methylated promoters. Methods and applications allowing clinicians to monitor the methylation of target genes will be also reviewed. [less ▲]

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See detailSequence-optimised E2 constructs from BVDV-1b and BVDV-2 for DNA immunisation in cattle
Couvreur, B.; Letellier, C.; Olivier, Fabrice ULg et al

in Veterinary Research (2007), 38(6, NOV-DEC), 819-834

We report DNA immunisation experiments in cattle using plasmid constructs that encoded glycoprotein E2 from bovine viral diarrhoea virus (BVDV)-1 (E2.1) and BVDV-2 (E2.2). The coding sequences were ... [more ▼]

We report DNA immunisation experiments in cattle using plasmid constructs that encoded glycoprotein E2 from bovine viral diarrhoea virus (BVDV)-1 (E2.1) and BVDV-2 (E2.2). The coding sequences were optimised for efficient expression in mammalian cells. A modified leader peptide sequence from protein gD of BoHV1 was inserted upstream of the E2 coding sequences for efficient membrane export of the proteins. Recombinant E2 were efficiently expressed in COS7 cells and they presented the native viral epitopes as judged by differential recognition by antisera from cattle infected with BVDV-1 or BVDV-2. Inoculation of pooled plasmid DNA in young cattle elicited antibodies capable of neutralising viral strains representing the major circulating BVDV genotypes. [less ▲]

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See detailPoint mutations in an infectious bovine viral diarrhoea virus type 2 cDNA transcript that yields an attenuated and protective viral progeny
Dehan, Pierre ULg; Couvreur, B.; Hamers, C. et al

in Vaccine (2005), 23(33), 4236-4246

An infectious cDNA clone of the hypervirulent bovine viral diarrhoea virus (BVDV) strain 890 (isolate 256) was produced by a streamlined PCR procedure. As compared to the published sequence of strain 890 ... [more ▼]

An infectious cDNA clone of the hypervirulent bovine viral diarrhoea virus (BVDV) strain 890 (isolate 256) was produced by a streamlined PCR procedure. As compared to the published sequence of strain 890, the nucleotide sequencing of cloned cDNA corresponding to isolate 256 revealed several mutations seven of which were attributed to the cloning procedure. The infectious transcript was transfected into permissive cells and led to viral multiplication (AvrII+ strain). In vitro, viral titres reached by the parental strain exceed those of the AvrII+ strain by more than one order of magnitude. The latter was clearly less virulent to young calves as indicated by clinical, haematological and virological parameters. Thirty-four days after inoculation with AvrII+ strain, calves were challenged with the virulent parental strain. The animals were protected as compared to unvaccinated controls. Therefore, our approach led to the production of an attenuated strain with potential use as a vaccine strain and will be useful for studies of virulence determinants in BVDV-2. (c) 2005 Elsevier Ltd. All rights reserved. [less ▲]

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See detailDiarrhée virale bovine et maladie des muqueuses
Pastoret, Paul-Pierre ULg; Hamers, C.; Dehan, Pierre ULg

in Lefevre, P.-C.; Blancou, J.; Chermette, R. (Eds.) Principales maladies infectieuses et parasitaires du bétail (2003)

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See detailDiversity among Bovine Pestiviruses
Hamers, C.; Dehan, Pierre ULg; Couvreur, B. et al

in Veterinary Journal (2001), 161(2), 112-22

Bovine viral diarrhoea virus (BVDV) isolates are characterized by an important genetic, antigenic and pathogenic diversity. The emergence of new hypervirulent BVDV strains in North America has provided ... [more ▼]

Bovine viral diarrhoea virus (BVDV) isolates are characterized by an important genetic, antigenic and pathogenic diversity. The emergence of new hypervirulent BVDV strains in North America has provided clear evidence of pathogenic differences between BVDV strains. The origin of BVDV diversity is related to high mutation rate occurring in RNA viruses but the consequences of mutations obviously depend on the genes which are involved. Mutations in genes encoding for structural proteins of immunological importance may have practical implications.Knowledge of BVDV diversity is important for understanding the wide variety of pathogenesis of diseases caused by the virus, for monitoring the epidemiology of the different types and for the design of optimum laboratory tests and vaccines.This review focuses on the origin and consequences of BVDV diversity with regard to pathogenesis, biotypes, and antigenic and genetic variations. [less ▲]

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See detailDown-Regulation of MT1-MMP expression by the alpha3 chain of type IV collagen inhibits bronchial tumor cell line invasion
Martinella-Catusse, C.; Polette, M.; Noël, Agnès ULg et al

in Laboratory Investigation : Journal of Technical Methods & Pathology (2001), 81

The basement membrane (BM) is the first barrier encountered by tumor cells when they become invasive. Moreover, some invasive tumor clusters are surrounded by a remnant or neosynthetized BM material. We ... [more ▼]

The basement membrane (BM) is the first barrier encountered by tumor cells when they become invasive. Moreover, some invasive tumor clusters are surrounded by a remnant or neosynthetized BM material. We have previously reported the presence of a particular alpha chain of type IV collagen, the alpha3(IV) chain, in bronchopulmonary carcinomas. This chain was not detected in the normal bronchial epithelium, but was found around some invasive tumor cluster BM. In the present study, we examined the effects of the alpha3(IV) chain on the invasive properties of bronchial tumor cell lines, with special emphasis on their expression of matrix metalloproteinase-2 (MMP-2) and its activator, membrane type 1-matrix metalloproteinase (MT1-MMP), which is largely involved in tumor progression. Two epithelial bronchial cell lines (16HBE14o- and BZR), showing different invasive abilities, were evaluated. Using the Boyden chamber invasion assay, we demonstrated that the alpha3(IV) chain inhibits the invasive properties of BZR cells and modifies their morphology by inducing an epithelial cell shape. In the presence of the recombinant NC1 domain of the alpha3(IV) chain, the expression of MMP-2 and tissue inhibitor of metalloproteinase-2 (TIMP-2) was not modified in either cell line. The NC1 alpha3(IV) domain did not modulate the MT1-MMP expression of noninvasive 16HBE14o- cells, whereas a 50% decrease of MT1-MMP mRNA was observed in invasive BZR cells. Accordingly, Western blot analyses showed a disappearance of the 45-kd MT1-MMP form when BZR cells were treated with the recombinant NC1 alpha3(IV) domain. These findings suggest that the alpha3 chain of type IV collagen may play a role in tumor invasion, at least by decreasing the expression and synthesis of MT1-MMP. [less ▲]

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See detailAvancées récentes en biologie moléculaire du virus de la diarrhée virale bovine
Dehan, Pierre ULg; Hamers, C.; Couvreur, B. et al

in Annales de Médecine Vétérinaire (2001), 145

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See detailDifferences in Experimental Virulence of Bovine Viral Diarrhoea Viral Strains Isolated from Haemorrhagic Syndromes
Hamers, C.; Couvreur, B.; Dehan, Pierre ULg et al

in Veterinary Journal (2000), 160(3), 250-8

In the late 1980s, a new hypervirulent and epidemic form of bovine viral diarrhoea virus (BVDV) infection appeared in North America. A similar but sporadic syndrome was later reported in Europe. To ... [more ▼]

In the late 1980s, a new hypervirulent and epidemic form of bovine viral diarrhoea virus (BVDV) infection appeared in North America. A similar but sporadic syndrome was later reported in Europe. To compare the pathogenic characters of the North American and European hypervirulent strains, we inoculated BVDV naive calves with BVDV strains isolated from haemorrhagic syndromes originating in Belgium, France and the USA. The experimental procedure comprised daily clinical examination and measurement of blood and virological parameters.The American BVD890/256 strain induced severe thrombocytopaenia, profuse diarrhoea and pneumonia in all calves, indicating that hypervirulent BVDV could be the primary infectious agent of pneumonia. Interestingly, a strong correlation was observed between the intense viraemia and a decreased platelet count. None of the European strains tested induced significant pathological signs, although isolated from cases presenting haemorrhagic syndrome. [less ▲]

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See detailLoss of type IV collagen alpha 5 and alpha 6 chains in human invasive prostate carcinomas
Dehan, Pierre ULg; Waltregny, David ULg; Beschin, Alain et al

in American Journal of Pathology (1997), 151(4), 1097-104

Type IV collagen, a major component of basement membranes, is organized in a network responsible for the mechanical resistance of the basement membranes. It also plays a key role in epithelial cell ... [more ▼]

Type IV collagen, a major component of basement membranes, is organized in a network responsible for the mechanical resistance of the basement membranes. It also plays a key role in epithelial cell adhesion to basement membranes. This study was designed to investigate the distribution of type IV collagen alpha-chains in normal, preneoplastic, and malignant prostate basement membranes. For this purpose, immunohistochemistry using specific antibodies raised against the different alpha-chains of type IV collagen was performed in eight normal samples, six prostatic intraepithelial neoplasia, and 20 malignant lesions of the prostate. Our results demonstrate the presence of the "novel" alpha 5 (IV) and alpha 6 (IV) chains along with the "classical" alpha 1 (IV)/alpha 2 (IV) chains in the basement membrane of the normal prostate gland. The alpha 3 (IV) chain was never detected in any prostate specimen. Prostatic intraepithelial neoplasia showed a similar immunostaining pattern to that found in normal glands. In cancer gland basement membranes, we demonstrate for the first time a specific loss of the alpha 5 (IV) and alpha 6 (IV) chains, whereas the classical alpha 1 (IV) and alpha 2 (IV) chains were consistently exhibited. Additionally, type VII collagen colocalized with alpha 5 (IV) collagen chain, and these two proteins, which were always observed in normal and prostatic intraepithelial neoplasia gland basement membranes, were lost in invasive carcinoma basement membranes. This observation raises questions about the possible association or cooperation between alpha 5 (IV)/alpha 6 (IV) chains and anchoring fibrils in prostate glands basement membrane. [less ▲]

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See detailIdentification of Post-Transplant Anti-Alpha 5 (Iv) Collagen Alloantibodies in X-Linked Alport Syndrome
Dehan, Pierre ULg; Van den Heuvel, L. P.; Smeets, H. J. et al

in Nephrology Dialysis Transplantation (1996), 11(10), 1983-8

X-linked Alport syndrome (AS) is a heritable disorder which is associated with mutations in the type IV collagen alpha 5 (IV) chain gene (COL4A5) located on chromosome X. Following renal transplantation ... [more ▼]

X-linked Alport syndrome (AS) is a heritable disorder which is associated with mutations in the type IV collagen alpha 5 (IV) chain gene (COL4A5) located on chromosome X. Following renal transplantation, an average of 6% of male AS patients develop anti-GBM nephritis. We studied the specificity of the antibodies against type IV collagen in the serum of a patient with COL4A5 partial deletion. The specificity of these alloantibodies was determined against collagenase-digested GBM, as well as against recombinant non-collagenous (NC1) domains of the type IV collagen alpha 1(IV)-alpha 6(IV) chains expressed in escherichia coli. Immunoblotting and ELISA demonstrated that these antibodies bound specifically to the NC1 domain of alpha 5(IV) collagen. There was no binding to the NC1 domain of the other chains, including the Goodpasture antigen. Competitive ELISA confirmed the results obtained by ELISA and immunoblotting. This patient developed alloantibodies directed against antigens present in the grafted kidney, but absent from his Alport kidney. The pathogenesis of post-transplantation glomerulonephritis in the Alport patient studied is thus similar to that of Goodpasture syndrome, with the exception that the pathogenic antibodies are targeted to another alpha chain of type IV collagen. [less ▲]

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See detailSera from patients with anti-GBM nephritis including goodpasture syndrome show heterogenous reactivity to recombinant NC1 domain of type IV collagen alpha chains.
Dehan, Pierre ULg; Weber, M.; Zhang, X. et al

in Nephrology Dialysis Transplantation (1996), 11(11), 2215-22

BACKGROUND: Goodpasture (GP) syndrome is defined by the clinical association of pulmonary haemorrhage with rapidly progressive glomerulonephritis. The disease is caused by pathogenic autoantibodies ... [more ▼]

BACKGROUND: Goodpasture (GP) syndrome is defined by the clinical association of pulmonary haemorrhage with rapidly progressive glomerulonephritis. The disease is caused by pathogenic autoantibodies directed against type IV collagen, which is a major structural component of glomerular basement membranes (GBM). METHODS: The non-collagenous domains (NC1) of all six human type IV collagen alpha chains was produced in E. coli as recombinant fusion proteins with glutathione-S transferase. Sera from 10 patients with different types of anti-GBM nephritis, including GP syndrome, were tested for reactivity with the six proteins using immunoblotting of denatured and reduced proteins and ELISA without reduction. RESULTS: All 10 sera reacted with the alpha 3 (IV) collagen chain by immunoblotting and ELISA. One serum also recognized the alpha 2(IV), alpha 4(IV), alpha 5(IV) and alpha 6(IV) chains by immunoblotting. ELISA measurements revealed reactivity of several other sera with alpha 2(IV), alpha 4(IV) or alpha 6(IV) but not with alpha 5(IV) collagen chains. No reactivity was observed with the alpha 1(IV) chain. CONCLUSION: Autoantibodies in anti-GBM nephritis may not be directed only against the alpha 3(IV) collagen chain and they frequently recognize conformational epitopes. [less ▲]

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See detailAnti-GBM antibodies from patients with Goodpasture Syndrome react with the NC1 domain of recombinant alpha3 (IV) and alpha4 (IV) collagen chains
Dehan, Pierre ULg; Weber, M.; Reeders, S. et al

in Journal of the American Society of Nephrology [=JASN] (1993), 4

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See detailCharacterization of anti-GBM antibody reactivity subsequent to renal transplantation in two Alport Syndrome patients
Dehan, Pierre ULg; Weber, M.; Reeders, S. et al

in Journal of the American Society of Nephrology [=JASN] (1993), 4

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See detailRelationship between interphasic nucleolar organizer regions and growth rate in two neuroblastoma cell lines.
Derenzini, M.; Pession, A.; Farabegoli, F. et al

in American Journal of Pathology (1989), 134(4), 925-32

The relationship between the quantity of silver-stained interphasic nucleolar organizer regions (NORs) and nuclear synthetic activity, caryotype, and growth rate was studied in two established ... [more ▼]

The relationship between the quantity of silver-stained interphasic nucleolar organizer regions (NORs) and nuclear synthetic activity, caryotype, and growth rate was studied in two established neuroblastoma cell lines (CHP 212 and HTB 10). Statistical analysis of silver-stained NORs revealed four times as many in CHP 212 cells compared with HTB 10 cells. No difference was observed in the ribosomal RNA synthesis between the two cell lines. The caryotype index was 1.2 for CHP 212 and 1.0 for HTB 10 cells. The number of chromosomes carrying NORs and the quantity of ribosomal genes was found to be the same for the two cell lines. Doubling time of CHP 212 cells was 20 hours compared with 54 hours for HTB 10 cells. In CHP 212 cells bindering of cell duplication by serum deprivation induced a progressive lowering (calculated at 48, 72, and 96 hours) of the quantity of silver-stained interphasic NORs. Recovery of duplication by new serum addition induced, after 24 hours, an increase of the quantity of silver-stained interphasic NORs up to control levels. In the light of available data, these results indicate that the quantity of interphasic NORs is strictly correlated only to the growth rate of the cell. [less ▲]

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See detailAction de l'hormone chorionique gonadotrope sur le reseau de jonctions permeables (gap junctions) existant dans les follicules antraux de rat.
Raick, D.; Dehan, Pierre ULg; Baeckeland, E.

in Comptes Rendus des Séances de la Société de Biologie et de ses Filiales (1987), 181(1), 40-5

A morphometrical study of gap junctions has been realized in rat antral follicle after an injection of 20 I. U. of hCG. A clear and rapid reduction of the gap junctions number and of the membranous ... [more ▼]

A morphometrical study of gap junctions has been realized in rat antral follicle after an injection of 20 I. U. of hCG. A clear and rapid reduction of the gap junctions number and of the membranous surface they are occupying has been demonstrated whatever the follicle region one consider. The significance of those gap junction modifications is discussed with respect to resumption of meiotic maturation. [less ▲]

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