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See detailInnovative Proteomics for the Discovery of Systemically Accessible Cancer Biomarkers Suitable for Imaging and Targeted Therapies
Turtoi, Andrei ULg; De Pauw, Edwin ULg; Castronovo, Vincenzo ULg

in American Journal of Pathology (2011), 178(1), 12-18

The discovery of biomarkers that are readily accessible through the circulating blood and are selectively overexpressed in pathological tissues has become a major research objective, particularly in the ... [more ▼]

The discovery of biomarkers that are readily accessible through the circulating blood and are selectively overexpressed in pathological tissues has become a major research objective, particularly in the field of oncology. Indisputably, this group of molecules has a high potential to serve as an innovative tool for effective imaging and targeted cancer therapy approaches. In this attractive therapeutic concept, specific cancer proteins are reached by intravenously administered ligands that are coupled to cytotoxic drugs. Such compounds are able to induce cancer destruction while sparing normal tissues. Owing to the performance of mass spectrometry technology, current high-throughput proteomic analysis allows for the identification of a high number of proteins that are differentially expressed in the cancerous tissues. However, such approaches provide no information regarding the effective accessibility of the biomarkers and, therefore, the possibility for these discovered proteins to be targeted. To bypass this major limitation, which clearly slows the discovery of such biomarkers, innovative methodological strategies have been developed to enrich the clinical specimens before the mass spectrometry analysis. The focus is laid on the group of proteins that are necessarily located either at the exterior face of the plasma membrane or in the extracellular matrix. The present review addresses the current technologies meant for the discovery and analysis of accessible antigens from clinically relevant samples. [less ▲]

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See detailPericyte requirement for anti-leak action of angiopoietin-1 and vascular remodeling in sustained inflammation
Fuxe, J.; Tabruyn, Sébastien ULg; Colton, K. et al

in American Journal of Pathology (2011), 178(6), 2897-909

Blood vessel leakiness is an early, transient event in acute inflammation but can also persist as vessels undergo remodeling in sustained inflammation. Angiopoietin/Tie2 signaling can reduce the leakiness ... [more ▼]

Blood vessel leakiness is an early, transient event in acute inflammation but can also persist as vessels undergo remodeling in sustained inflammation. Angiopoietin/Tie2 signaling can reduce the leakiness through changes in endothelial cells. The role of pericytes in this action has been unknown. We used the selective PDGF-B-blocking oligonucleotide aptamer AX102 to determine whether disruption of pericyte-endothelial crosstalk alters vascular leakiness or remodeling in the airways of mice under four different conditions: i) baseline, ii) acute inflammation induced by bradykinin, iii) sustained inflammation after 7-day infection by the respiratory pathogen Mycoplasma pulmonis, or iv) leakage after bradykinin challenge in the presence of vascular stabilization by the angiopoietin-1 (Ang1) mimic COMP-Ang1 for 7 days. AX102 reduced pericyte coverage but did not alter the leakage of microspheres from tracheal blood vessels at baseline or after bradykinin; however, AX102 exaggerated leakage at 7 days after M. pulmonis infection and increased vascular remodeling and disease severity at 14 days. AX102 also abolished the antileakage effect of COMP-Ang1 at 7 days. Together, these findings show that pericyte contributions to endothelial stability have greater dependence on PDGF-B during the development of sustained inflammation, when pericyte dynamics accompany vascular remodeling, than under baseline conditions or in acute inflammation. The findings also show that the antileakage action of Ang1 requires PDGF-dependent actions of pericytes in maintaining endothelial stability. [less ▲]

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See detailAngiopoietin/Tie2 signaling transforms capillaries into venules primed for leukocyte trafficking in airway inflammation.
Fuxe, Jonas; Lashnits, Erin; O'Brien, Shaun et al

in American Journal of Pathology (2010), 176(4), 2009-18

Vascular endothelial growth factor (VEGF) is a key angiogenic factor in tumors, but less is known about what drives vascular remodeling in inflammation, where plasma leakage and leukocyte influx are ... [more ▼]

Vascular endothelial growth factor (VEGF) is a key angiogenic factor in tumors, but less is known about what drives vascular remodeling in inflammation, where plasma leakage and leukocyte influx are prominent features. In chronic airway inflammation in mice infected by the bacterium Mycoplasma pulmonis (M. pulmonis), the segment of the microvasculature that supports leukocyte adhesion and migration expands through remodeling of capillaries into vessels with features of venules. Here, we report that the angiopoietin/Tie2 pathway is an essential driving force for capillary remodeling into venules in M. pulmonis-infected mouse airways. Similar to M. pulmonis infection, systemic overexpression of angiopoietin-1 (Ang1) resulted in remodeling of airway capillaries into venular-like vessels that expressed venous markers like P-selectin, ICAM-1, and EphB4 and were sites of leukocyte adhesion during lipopolysaccharide-induced acute inflammation. Ang1 and Ang2 protein increased in M. pulmonis-infected mouse airways but came from different cellular sources: Ang1 was expressed in infiltrating neutrophils and Ang2 in endothelial cells. Indeed, systemic administration of soluble Tie2 inhibited capillary remodeling, induction of venous markers, and leukocyte influx in M. pulmonis-infected mouse airways. Together, these findings suggest that blockade of the Ang/Tie2 pathway may represent a therapeutic approach in airway inflammation. [less ▲]

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See detailAngiopoietin-2-Driven Vascular Remodeling in Airway Inflammation
Tabruyn, Sébastien ULg; Colton, K.; Morisada, T. et al

in American Journal of Pathology (2010)

Vascular remodeling is a feature of chronic inflammation during which capillaries transform into venules that expand the region of the vasculature in which leakage and leukocyte emigration both occur ... [more ▼]

Vascular remodeling is a feature of chronic inflammation during which capillaries transform into venules that expand the region of the vasculature in which leakage and leukocyte emigration both occur. Recently, we found that angiopoietin/Tie2 receptor signaling drives the transformation of capillaries into venules at an early stage of the sustained inflammatory response in the airways of mice infected with Mycoplasma pulmonis. However, the precise contributions of both angiopoietin-1 (Ang1) and angiopoietin-2 (Ang2) are not clear. In this study, we sought to determine the contribution of Ang2 to this vascular remodeling. Ang2 mRNA expression levels increased and phosphorylated Tie2 immunoreactivity in mucosal blood vessels decreased, indicative of diminished receptor signaling after infection. Selective inhibition of Ang2 throughout the infection by administration of either of two distinct function-blocking antibodies reduced the suppression of Tie2 phosphorylation and decreased the remodeling of mucosal capillaries into venules, the amount of leukocyte influx, and disease severity. These findings are consistent with Ang2 acting as an antagonist of Tie2 receptors and the reduction of Tie2 phosphorylation in endothelial cells rendering the vasculature more responsive to cytokines that promote both vascular remodeling and the consequences of inflammation after M. pulmonis infection. By blocking such changes, Ang2 inhibitors may prove beneficial in the treatment of sustained inflammation in which vascular remodeling, leakage, and leukocyte influx contribute to its pathophysiology. [less ▲]

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See detailIncrease in viral load, viral integration, and gain of telomerase genes during uterine cervical carcinogenesis can be simultaneously assessed by the HPV 16/18 MLPA-assay.
Theelen, Wendy; Speel, Ernst*-Jan M; Herfs, Michael ULg et al

in American Journal of Pathology (2010), 177(4), 2022-33

Oncogenic human papillomavirus (HPV) infection is the most important risk factor in cervical carcinogenesis cases; high viral loads, viral integration into the host genome, and gain of the telomerase ... [more ▼]

Oncogenic human papillomavirus (HPV) infection is the most important risk factor in cervical carcinogenesis cases; high viral loads, viral integration into the host genome, and gain of the telomerase-related genes, TERT and TERC, are all factors associated with progression to cancer. A recently developed multiparameter HPV 16/18 multiplex ligation-dependent probe amplification (MLPA) assay, which allows the simultaneous assessment of these factors, was applied to a series of 67 normal and (pre)malignant frozen uterine cervical samples, as well as to 91 cytological preparations, to test the ability of the MLPA assay to identify high-risk lesions on the basis of these factors. Validation was performed using quantitative PCR, the PapilloCheck and fluorescence in situ hybridization. Only 5 out of 37 normal tissue samples or low-grade cervical lesions (ie, CIN1 and condyloma) showed either an HPV16 viral load higher than 25 copies per cell, viral integration, and/or gain of one of the telomerase-related genes, whereas for the high-grade cervical lesions, one or more of these risk factors was found in 25 of 30 cases. The HPV MLPA assay showed a sensitivity of 83% and a specificity of 86% in frozen cervical specimens. Furthermore, the feasibility of the MLPA assay was shown for cytological samples, where in 57% of high-grade squamous intraepithelial lesion cases, the high-risk factors were detected using this assay. [less ▲]

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See detailRegulation of p63 Isoforms by Snail and Slug Transcription Factors in Human Squamous Cell Carcinoma.
Herfs, Michael ULg; Hubert, Pascale ULg; Suarez-Carmona, Meggy ULg et al

in American Journal of Pathology (2010), 176(4), 1941-1949

TP63 is a p53-related gene that contains two alternative promoters, which give rise to transcripts that encode proteins with (TAp63) or without (DeltaNp63) an amino-transactivating domain. Whereas the ... [more ▼]

TP63 is a p53-related gene that contains two alternative promoters, which give rise to transcripts that encode proteins with (TAp63) or without (DeltaNp63) an amino-transactivating domain. Whereas the expression of p63 is required for proper development of epithelial structures, the role of p63 in tumorigenesis remains unclear. Here, we investigated the role of Snail and Slug transcription factors, known to promote epithelial-to-mesenchymal transitions during development and cancer, in the regulation of p63 isoforms in human squamous cell carcinoma (SCC). In the present study, we observed that the expressions of DeltaN and TAp63 isoforms were, respectively, down- and up-regulated by both Snail and Slug. However, the induction of TAp63 was not directly caused by these two transcription factors but resulted from the loss of DeltaNp63, which acts as dominant-negative inhibitor of TAp63. In SCC cell lines and cancer tissues, high expression of Snail and Slug was also significantly associated with altered p63 expression. Finally, we showed that DeltaNp63 silencing reduced cell-cell adhesion and increased the migratory properties of cancer cells. These data suggest that the disruption of p63 expression induced by Snail and Slug plays a crucial role in tumor progression. Therefore, p63 and its regulating factors could constitute novel prognosis markers in patients with SCC and attractive targets for the therapeutic modulation of neoplastic cell invasiveness. [less ▲]

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See detailIL-4Ralpha responsiveness of non-CD4 T cells contributes to resistance in schistosoma mansoni infection in pan-T cell-specific IL-4Ralpha-deficient mice.
Dewals, Benjamin G ULg; Hoving, Jennifer C; Leeto, Mosiuoa et al

in American Journal of Pathology (2009), 175(2), 706-16

Interleukin (IL)-4 and IL-13 are T helper 2 cytokines whose biological functions are induced through a common IL-4 receptor alpha chain (IL-4Ralpha). CD4(+) T cell-specific IL-4Ralpha-mediated signaling ... [more ▼]

Interleukin (IL)-4 and IL-13 are T helper 2 cytokines whose biological functions are induced through a common IL-4 receptor alpha chain (IL-4Ralpha). CD4(+) T cell-specific IL-4Ralpha-mediated signaling drives susceptibility to Leishmania major infection, but is not essential to host survival following Schistosoma mansoni infection. Here we generated a novel mouse model lacking IL-4Ralpha expression specifically on all T cells (iLck(cre)Il4ra(-/lox)), which was compared with CD4(+) T cell-specific IL-4Ralpha-deficient mice (Lck(cre)Il4ra(-/lox)), to investigate the possible roles of IL-4Ralpha responsive non-CD4(+) T cells during either L. major or S. mansoni infection. Our results demonstrate a successful generation of transgene-bearing hemizygous iLck(cre)Il4ra(-/lox) BALB/c mice that have effective deletion of IL-4Ralpha on all T-cell populations. We show that iLck(cre)Il4ra(-/lox) mice infected with L. major developed a healing disease phenotype as previously observed in Lck(cre)Il4ra(-/lox) mice, demonstrating that absence of IL-4Ralpha-responsive non-CD4(+) in addition to CD4(+) T cells does not further affect transformation of BALB/c to a healer phenotype. In acute schistosomiasis, however, iLck(cre)Il4ra(-/lox) mice showed enhanced mortality compared with Il4ra(-/lox) and Lck(cre)Il4ra(-/lox) mice. iLck(cre)Il4ra(-/lox) mice died with similar kinetics to highly susceptible Il4ra(-/-) mice, despite controlling gut inflammation. In addition, iLck(cre)Il4ra(-/lox) mice presented increased liver granuloma sizes, as compared with Lck(cre)Il4ra(-/lox) mice, with similar eosinophils, fibrosis, and liver damage. In conclusion, IL-4Ralpha-responsive non-CD4(+) T cells prolong survival to acute schistosomiasis and contribute to the better control of hepatic granulomatous inflammation. [less ▲]

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See detailTransforming growth factor-beta1-mediated Slug and Snail transcription factor up-regulation reduces the density of Langerhans cells in epithelial metaplasia by affecting E-cadherin expression
Herfs, Michael ULg; Hubert, Pascale ULg; Kholod, Natalia et al

in American Journal of Pathology (2008), 172(5), 1391-402

Epithelial metaplasia (EpM) is an acquired tissue abnormality resulting from the transformation of epithelium into another tissue with a different structure and function. This adaptative process is ... [more ▼]

Epithelial metaplasia (EpM) is an acquired tissue abnormality resulting from the transformation of epithelium into another tissue with a different structure and function. This adaptative process is associated with an increased frequency of (pre)cancerous lesions. We propose that EpM is involved in cancer development by altering the expression of adhesion molecules important for cell-mediated antitumor immunity. Langerhans cells (LCs) are intraepithelial dendritic cells that initiate immune responses against viral or tumor antigens on both skin and mucosal surfaces. In the present study, we showed by immunohistology that the density of CD1a LCs is reduced in EpM of the uterine cervix compared with native squamous epithelium and that the low number of LCs observed in EpM correlates with the down-regulation of cell-surface E-cadherin. We also demonstrated that transforming growth factor- 1 is not only overexpressed in metaplastic tissues but also reduces E-cadherin expression in keratinocytes in vitro by inducing the promoter activity of Slug and Snail transcription factors. Finally, we showed that in vitro-generated LCs adhere poorly to keratinocytes transfected with either Slug or Snail DNA. These data suggest that transforming growth factor- 1 indirectly reduces antigenpresenting cell density in EpM by affecting E-cadherin expression, which might explain the increased susceptibility of abnormal tissue differentiation to the development of cancer by the establishment of local immunodeficiency responsible for EpM tumorigenesis. [less ▲]

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See detailTumoral and choroidal vascularization: differential cellular mechanisms involving plasminogen activator inhibitor type I.
Jost, Maud; Maillard, Catherine ULg; Lecomte, Julie ULg et al

in American Journal of Pathology (2007), 171(4), 1369-80

An adequate balance between serine proteases and their plasminogen activator inhibitor-1 (PAI-1) is critical for pathological angiogenesis. PAI-1 deficiency in mice is associated with impaired choroidal ... [more ▼]

An adequate balance between serine proteases and their plasminogen activator inhibitor-1 (PAI-1) is critical for pathological angiogenesis. PAI-1 deficiency in mice is associated with impaired choroidal neovascularization (CNV) and tumoral angiogenesis. In the present work, we demonstrate unexpected differences in the contribution of bone marrow (BM)-derived cells in these two processes regulated by PAI-1. PAI-1(-/-) mice grafted with BM-derived from wild-type mice were able to support laser-induced CNV formation but not skin carcinoma vascularization. Engraftment of irradiated wild-type mice with PAI-1(-/-) BM prevented CNV formation, demonstrating the crucial role of PAI-1 delivered by BM-derived cells. In contrast, the transient infiltration of tumor transplants by local PAI-1-producing host cells rather than by BM cells was sufficient to rescue tumor growth and angiogenesis in PAI-1-deficient mice. These data identify PAI-1 as a molecular determinant of a local permissive soil for tumor angiogenesis. Altogether, the present study demonstrates that different cellular mechanisms contribute to PAI-1-regulated tumoral and CNV. PAI-1 contributes to BM-dependent choroidal vascularization and to BM-independent tumor growth and angiogenesis. [less ▲]

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See detailExpression of histone deacetylase 8, a class I histone deacetylase, is restricted to cells showing smooth muscle differentiation in normal human tissues
Waltregny, David ULg; de Leval, Laurence ULg; Glenisson, Wendy et al

in American Journal of Pathology (2004), 165(2), 553-564

Histone deacetylases (HDACs) were originally identified as nuclear enzymes involved in gene transcription regulation. Until recently, it was thought that their activity was restricted within the nucleus ... [more ▼]

Histone deacetylases (HDACs) were originally identified as nuclear enzymes involved in gene transcription regulation. Until recently, it was thought that their activity was restricted within the nucleus, with histones as unique substrates. The demonstration that specific HDACs deacetylate nonhistone proteins, such as p53 and alpha-tubulin, broadened the field of activity of these enzymes. HDAC8, a class I HDAC, is considered to be ubiquitously expressed, as suggested by results of Northern blots performed on tissue RNA extracts, and transfection experiments using various cell lines have indicated that this enzyme may display a prominent nuclear localization. Using immunohistochemistry, we unexpectedly found that, in normal human tissues, HDAC8 is exclusively expressed by cells showing smooth muscle differentiation, including visceral and vascular smooth muscle cells, myoepithelial cells, and myofibroblasts, and is mainly detected in their cytosol. These findings were confirmed in vitro by nucleo-cytoplasmic fractionation and immunoblot experiments performed on human primary smooth muscle cells, and by the cytosolic detection of epitope-tagged HDAC8 overexpressed in fibroblasts. Immunocytochemistry strongly suggested a cytoskeleton-like distribution of the enzyme. Further double-immunofluorescence staining experiments coupled with confocal microscopy analysis showed that epitope-tagged HDAC8 overexpressed in murine fibroblasts formed cytoplasmic stress fiber-like structures that co-localized with the smooth muscle cytoskeleton protein smooth muscle alpha-actin. Our works represent the first demonstration of the restricted expression of a class I HDAC to a specific cell type and indicate that HDAC8, besides being a novel marker of smooth muscle differentiation, may play a role in the biology of these contractile cells. [less ▲]

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See detailMultifunctional role of matrix metalloproteinases in multiple myeloma: a study in the 5T2MM mouse model
Van Valckenborgh, Els; Croucher, Peter I.; De Raeve, Hendrik et al

in American Journal of Pathology (2004), 165(3), 869-878

Matrix metalloproteinases (MMPs) are known to play a role in cell growth, invasion, angiogenesis, metastasis, and bone degradation, all important events in the pathogenesis of cancer. Multiple myeloma is ... [more ▼]

Matrix metalloproteinases (MMPs) are known to play a role in cell growth, invasion, angiogenesis, metastasis, and bone degradation, all important events in the pathogenesis of cancer. Multiple myeloma is a B-cell cancer characterized by the proliferation of malignant plasma cells in the bone marrow, increased angiogenesis, and the development of osteolytic bone disease. The role of MMPs in the development of multiple myeloma is poorly understood. Using SC-964, a potent inhibitor of several MMPs (MMP-2, -3, -8, -9, and -13), we investigated the role of MMPs in the 5T2MM murine model. Reverse transcriptase-polymerase chain reaction demonstrated the presence of mRNA for MMP-2, -8, -9, and -13 in 5T2MM-diseased bone marrow. Mice bearing 5T2MM cells were given access to food containing SC-964. The concentration of SC-964 measured in the plasma of mice after 11 days of treatment was able to inhibit MMP-9 activity in gelatin zymography. Treatment of 5T2MM-bearing mice resulted in a significant reduction in tumor burden, a significant decrease in angiogenesis, and partially protective effect against the development of osteolytic bone disease. The direct role of MMPs in these different processes was confirmed by in vitro experiments. All these results support the multifunctional role of MMPs in the development of multiple myeloma. [less ▲]

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See detailProteases, extracellular matrix and cancer: a workshop of the path B study section
Declerck, Y. A.; Mercurio, A. M.; Stack, M. S. et al

in American Journal of Pathology (2004), 164(4), 1131-39

The role of the extracellular matrix (ECM) in the tumor microenvironment is not limited to being a barrier against tumor invasion. The ECM is a reservoir of cell binding proteins and growth factors that ... [more ▼]

The role of the extracellular matrix (ECM) in the tumor microenvironment is not limited to being a barrier against tumor invasion. The ECM is a reservoir of cell binding proteins and growth factors that affect tumor cell behavior. It is also substantially modified by proteases produced by tumor cells or stroma cells. As a result of the activity of these proteases, cell-cell and cell-ECM interactions are altered, new biologically active ECM molecules are generated, and the bioavailability and activity of many growth factors, growth factor receptors, and cytokines are modified. ECM-degrading proteases also play a critical role in angiogenesis, where they can act as positive as well as negative regulators of endothelial cell proliferation and vascular morphogenesis. This review article summarizes some of the most relevant findings made over the recent years that were discussed at a workshop organized by the Path B Study Section of the National Institutes of Health in October 2002. [less ▲]

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See detailE-cadherin mediates MMP down-regulation in highly invasive bronchial tumor cells
Nawrocki-Raby, B.; Gilles, Christine ULg; Polette, M. et al

in American Journal of Pathology (2003), 163(2), 653-661

The disorganization of E-cadherin/catenin complexes and the overexpression of matrix metalloproteinases (MMPs) are frequently involved in the capacity of epithelial cells to acquire an invasive phenotype ... [more ▼]

The disorganization of E-cadherin/catenin complexes and the overexpression of matrix metalloproteinases (MMPs) are frequently involved in the capacity of epithelial cells to acquire an invasive phenotype. The functional link between F-cadherin and MMPs was studied by transfecting invasive bronchial BZR tumor cells with human E-cadherin cDNA. Using different in vitro (cell dispersion, modified Boyden chamber) and in vivo assays (human airway epithelial xenograft), we showed that E-cadherin-positive clones displayed a decrease of invasive abilities. As shown by immunoprecipitation, the re-expressed E-cadherin was able to sequestrate one part of free cytoplasmic beta-catenin in BZR cells. The decrease of beta-catenin transcriptional activity in E-cadherin-transfected clones was demonstrated using the TOP-FLASH reporter construct. Finally, we observed a decrease of MMP-1, MMP-3, MMP-9, and MT1-MMP, both at the mRNA and at the protein levels, in E-cadherin-positive clones whereas no changes in MMP-2, TIMP-1, or TIMP-2 were observed when compared with control clones. Moreover, zymography analysis revealed a loss of MMP-2 activation ability in E-cadherin-positive clones treated with the concanavalin A lectin. These data demonstrate a direct role of E-cadherin/catenin complex organization in the regulation of MMPs and suggest an implication of this regulation in the expression of an invasive phenotype by bronchial tumor cells. [less ▲]

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See detailMatrix metalloproteinase-9 contributes to choroidal neovascularization
Lambert, Vincent ULg; Munaut, Carine ULg; Jost, M. et al

in American Journal of Pathology (2002), 161(4), 1247-1253

Age-related macular degeneration (AMD) is the primary cause of irreversible photoreceptors loss in adult patients and current therapies are limited. Increased levels of matrix metalloproteinases (MMPs ... [more ▼]

Age-related macular degeneration (AMD) is the primary cause of irreversible photoreceptors loss in adult patients and current therapies are limited. Increased levels of matrix metalloproteinases (MMPs) have been documented in neovascularization of severe ocular pathologies such as AMD and proliferative diabetic retinopathy. We report here that MMP-9 (gelatinase B) expression is induced and temporally regulated in the course of experimental choroidal neovascularization. We used transgenic mice expressing beta-galactosidase reporter gene under the dependence of MMP-9 promoter and RT-PCR analysis on choroidal neovascular structures microdissected from serial sections by laser pressure catapulting to show that MMP-9 expression is up-regulated concomitantly with the appearance of inflammatory cells in the subretinal lesion. In mice deficient in MMP-9 expression the development of choroidal neovascularization induced by laser photocoagulation still occurred, but at a reduced level. [less ▲]

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See detailMatrix metalloproteinase-9 deficiency impairs cellular infiltration and bronchial hyperresponsiveness during allergen-induced airway inflammation
Cataldo, Didier ULg; Tournoy, K. G.; Vermaelen, K. et al

in American Journal of Pathology (2002), 161(2), 491-498

We investigated the specific role of matrix metalloproteinase (MMP)-9 in allergic asthma using a murine model of allergen-induced airway inflammation and airway hyperresponsiveness in MMP-9(-/-) mice and ... [more ▼]

We investigated the specific role of matrix metalloproteinase (MMP)-9 in allergic asthma using a murine model of allergen-induced airway inflammation and airway hyperresponsiveness in MMP-9(-/-) mice and their corresponding wild-type (WT) littermates. After a single intraperitoneal sensitization to ovalbumin, the mice were exposed daily either to ovalbumin (1%) or phosphate-buffered saline aerosols from days 14 to 21. Significantly less peribronchial mononuclear cell infiltration of the airways and less lymphocytes in the bronchoalveolar lavage fluid were detected in challenged MMP-9(-/-) as compared to WT mice. In contrast, comparable numbers of bronchoalveolar lavage fluid eosinophils; were observed in both genotypes. After allergen exposure, the WT mice developed a significant airway hyperresponsiveness to carbachol whereas the MMP-9(-/-) mice failed to do so. Allergen exposure induced an increase of MMP-9-related gelatinolytic activity in WT lung extracts. Quantitative reverse transcriptase-polymerase chain reaction showed increased mRNA levels of MMP-12, MMP-14, and urokinase-type plasminogen activator after allergen exposure in the lung extracts of WT mice but not in MMP-9-deficient mice. in contrast, the expression of tissue inhibitor of metalloproteinases-1 was enhanced after allergen exposure in both groups. We conclude that MMP-9 plays a key role in the development of airway inflammation after allergenexposure. [less ▲]

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See detailAnti-CD3/anti-epidermal growth factor receptor-bispecific antibody retargeting of lymphocytes against human neoplastic keratinocytes in an autologous organotypic culture model
Renard, I.; Mezzanzanica, Delia; Canevari, Silvana et al

in American Journal of Pathology (2002), 160(1), 113-122

Local cellular immune defects have been described in several tumors including human papillomavirus (HPV)-associated cervical cancer. This observation suggests the potential therapeutic benefit of immune ... [more ▼]

Local cellular immune defects have been described in several tumors including human papillomavirus (HPV)-associated cervical cancer. This observation suggests the potential therapeutic benefit of immune manipulations that restore cellular immunity. Here, we evaluated the ability of bispecific monoclonal antibodies (bimAbs) to redirect T cells against keratinocytes transformed in vitro by HPV in an autologous three-dimensional culture model (organotypic cultures). The epidermal growth factor receptor (EGFR) was chosen as target for an anti-CD3/anti-EGFR bimAb because it is overexpressed in many malignant epithelial lesions and only weakly expressed in the basal layers of normal squamous epithelium. Interestingly, in organotypic cultures, the pattern of expression of EGFR was similar to that observed in vivo. The ability of T cells retargeted by CD3/EGFR bimAb to lyse HPV-transformed cell lines was confirmed in monolayer cultures. In autologous organotypic cultures, an increase in apoptotic HPV(+) keratinocytes and a significant decrease in the thickness of HPV(+) organotypic cultures were observed when activated lymphocytes and bimAbs were added to the cultures, whereas organotypic cultures of normal keratinocytes were not significantly affected. These data were similar to those obtained in the allogeneic model. These results suggest the potential usefulness of CD3-EGFR bimAb-retargeted lymphocytes in immunotherapeutic protocols for malignant epithelial lesions. [less ▲]

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See detailp63 is a prostate basal cell marker and is required for prostate development.
Signoretti, Sabina; Waltregny, David ULg; Dilks, James et al

in American Journal of Pathology (2000), 157(6), 1769-75

The p53 homologue p63 encodes for different isotypes able to either transactivate p53 reporter genes (TAp63) or act as p53-dominant-negatives (DeltaNp63). p63 is expressed in the basal cells of many ... [more ▼]

The p53 homologue p63 encodes for different isotypes able to either transactivate p53 reporter genes (TAp63) or act as p53-dominant-negatives (DeltaNp63). p63 is expressed in the basal cells of many epithelial organs and its germline inactivation in the mouse results in agenesis of organs such as skin appendages and the breast. Here, we show that prostate basal cells, but not secretory or neuroendocrine cells, express p63. In addition, prostate basal cells in culture predominantly express the DeltaNp63alpha isotype. In contrast, p63 protein is not detected in human prostate adenocarcinomas. Finally, and most importantly, p63(-/-) mice do not develop the prostate. These results indicate that p63 is required for prostate development and support the hypothesis that basal cells represent and/or include prostate stem cells. Furthermore, our results show that p63 immunohistochemistry may be a valuable tool in the differential diagnosis of benign versus malignant prostatic lesions. [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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