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J M Foidart

Publications and source records attributed to J M Foidart.

At least 127 records · Page 7Linked to original sources
PubMed1997

[Stromal proteases in the progression of breast cancer].

Matrix metalloproteases represent a family of proteases secreted as latent inactive enzymes able to degrade the majority of extracellular matrix components. These enzymes are overexpressed during several pathological tissue remodelings including tumor progression and tumor invasion. It was indeed classically admitted that matrix metalloproteases involved in tumoral progression were preferentially expressed by cancerous cells. Our studies on gelatinase A and stromelysin-3 have, however, demonstrated that their messenger RNAS are detected in fibroblasts of the peritumoral stroma in human mammary carcinoma and not in the cancerous cells themselves. By immunohistochemistry, we have detected gelatinase A in the cytoplasm of fibroblasts and at the surface of the tumor cells. This membrane localization of the protein could result from its binding, following secretion by the neighbouring stromal cells, to a specific binding site expressed at the surface of the carcinoma cells. These cells are indeed able to induce an increased proteolytic activity by enhancing the transcription of these enzymes by peritumoral fibroblasts. These enzymes represent therefore potential targets for the development of new therapeutic strategies.

Breast Neoplasms↗
PubMed1997

Emerging roles for proteinases in cancer.

Metalloproteinases and serine proteinases have been associated with tumor invasion and formation of metastasis which represent the major obstacles to cancer cure. The contribution of proteinases in these processes was initially thought to be the destruction of extracellular matrices. However, recent evidence suggests that they mainly affect tumor growth rather than invasion. Proteinases can indeed generate active matrix protein fragments, influence the release, the activation and the bioavailability of growth factors, and consequently modulate tumor cell growth, apoptosis and angiogenesis. Additionally, proteinases, their receptors and/or inhibitors can be directly involved in cell migration and in the processing or shedding of cell surface proteins. Further elucidation of the functions of proteinases is essential for the development of novel anticancer strategies.

Animals↗
PubMed1996

Heparin-binding domain, type 1 and type 2 repeats of thrombospondin mediate its interaction with human breast cancer cells.

Thrombospondin is an adhesive glycoprotein that promotes breast cancer cell adhesion to human vascular endothelial cells (Incardona et al., 1995). In this study, we have identified the molecular domains of thrombospondin that mediate its binding to specific receptors on the human breast adenocarcinoma cell line, MDA-MB-231. Two recombinant fragments from the amino-terminus (TSPN18 and TSPN28), and the fusion proteins of the type 1 and type 2 repeats of human thrombospondin, inhibited binding of radiolabeled thrombospondin to MDA-MB-231 cells in suspension by 40-60% at 50 micrograms/ml whereas the type 3 repeat, carboxy-terminus and unfused glutathione-S-transferase as well as the synthetic peptide Gly-Arg-Gly-Asp-Ser (500 micrograms/ml) had little or no effect. Heparin and various glycosaminoglycans as heparan sulfate, chondroitin sulfates A, B or C, and fucoidan inhibited thrombospondin binding to MDA-MB-231 cells by more than 60% whereas dextran sulfate had only little effect. Treatment of cells with heparitinase, chondroitinase ABC, and hyaluronidase, but not with neuraminidase, induced 30-50% inhibition of thrombospondin binding suggesting the participation of both heparan sulfate and chondroitin sulfate cell surface-associated molecules. Inhibition of proteoglycan sulfation by chlorate or inhibition of glycosaminoglycan chain formation by two beta-D-xylosides also led to a substantial inhibition of thrombospondin binding. Our results indicate that several domains within the thrombospondin molecule, namely the amino-terminus, type 1 and type 2 repeats, participate in its binding to specific receptors bearing sulfated glycosaminoglycans on MDA-MB-231 cells. Biological assays have indicated that, in addition to these domains, the peptide Gly-Arg-Gly-Asp-Ser inhibited MDA-MB-231 cell attachment to thrombospondin suggesting that the last type 3 repeat of the molecule may also contribute to its cell adhesive activity.

Binding Sites↗
PubMed1996

Cloning of choriocarcinoma cells shows that invasion correlates with expression and activation of gelatinase A.

Implantation and placental development are dependent upon trophoblast invasion of the endometrium. While the villous trophoblast does not display invasive behavior, the extravillous cytotrophoblast is highly invasive. By cloning BeWo choriocarcinoma cells, we have isolated two distinct clones that share similarities with villous and extravillous cytotrophoblasts. When cultured at the surface of a type I collagen gel, BeWo MC-1 cells were not invasive, whereas BeWo MC-2 cells rapidly invaded this matrix. When injected subcutaneously in nude mice, BeWo MC-1 cells developed a localized tumor and BeWo MC-2 cells developed larger tumors with micrometastases. Gelatinase A expression and minute amounts of gelatinase B were detected in the parental cell line and in both clones. However, the parental and the BeWo MC-2 cells secreted 5-to 10-fold more gelatinase A than the BeWo MC-1 cells. Laminin and matrigel stimulated the production of gelatinase A in BeWo MC-2 cells. Type I collagen promoted the conversion of the 72-kDa progelatinase A in an active enzyme only in parental BeWo and in BeWo MC-2 cells. These clones provide an interesting model for studying the complex mechanisms regulating implantation as well as the controlled invasiveness during implantation compared to tumor invasion.

Animals↗
PubMed1996

Stromelysin-3 expression promotes tumor take in nude mice.

Stromelysin-3 (ST3) is a matrix metalloproteinase expressed in human carcinomas in ways suggesting that it may play a role in tumor progression. To test this possibility, we have performed gene transfer experiments using both anti-sense and sense ST3 expression vectors, and malignant cells either expressing (NIH 3T3 fibroblasts) or not (MCF7 epithelial cells) endogenous ST3. We have compared the ability of parental and transfected cells to cause subcutaneous tumor development in nude mice. 3T3 cells expressing anti-sense ST3 RNA showed reduced tumorigenicity, and MCF7 cells expressing mouse or human ST3 were associated with reduced tumor-free period leading to a significant increased tumor incidence(P<10(-4)). However, once established, the ST3 expressing tumors did not grow faster than those obtained with the parental MCF7 cell line. In addition, tumors obtained after sub-cutaneous injection of ST3-expressing or nonexpressing cells did not exhibit obvious histological differences, and careful examination did not reveal any local invasive tissue areas nor systemic metastases. These in vivo observations were in agreement with those obtained in vitro showing that ST3 expression did not modify proliferative nor invasive properties of transfected cells. Altogether, these results indicate that ST3 expression promotes tumor take in nude mice, presumably by favoring cancer cell survival in a tissue environment initially not permissive for tumor growth. These findings represent the first experimental evidence showing that ST3 can modulate cancer progression.

3T3 Cells↗
PubMed1996

High level of MT-MMP expression is associated with invasiveness of cervical cancer cells.

MMP-2 (gelatinase A) has been associated with the invasive potential of many cancer cells both in vitro and in vivo. It is now becoming clear that the activation of this enzyme might be a key step in tumor invasion. This activation process has been shown to be a membrane-associated pathway inducible by various agents such as collagen type I, concanavalin A or TGF-beta, but its physiological regulation is still largely unresolved. MT-MMP was recently discovered and described as a potential gelatinase-A activator. In the present study, we investigated the expression of MT-MMP (membrane-type metalloproteinase) in cervical cancer cells both in vitro and in vivo. Comparing several in vitro-transformed cervical cell lines, previously shown to display different invasive potentials, our results showed that the ability of cells to overexpress MT-MMP mRNA following ConA induction correlated with their ability to activate gelatinase A and with a highly invasive behavior. Moreover, using immunohistochemistry and in situ hybridization, we found a higher level of MT-MMP expression in invasive cervical carcinoma and lymph node metastases compared to its expression in non-invasive CIN III lesions. Our in vivo observations also clearly demonstrated a cooperation between stromal and tumor cells for the production of MT-MMP. Taken together, our results clearly correlated high level MT-MMP expression with invasiveness, and thus suggested that MT-MMP might play a crucial role in cervical tumor invasion.

Base Sequence↗
PubMed1996

Vimentin expression in cervical carcinomas: association with invasive and migratory potential.

Vimentin is an intermediate filament protein normally expressed in mesenchymal cells, but evidence is accumulating in the literature which suggests that the aberrant expression of vimentin in epithelial cancer cells might be related to local invasiveness and metastatic potential. Vimentin expression has previously been associated with invasive properties in an in vitro model consisting of a set of HPV-33-transformed cervical keratinocyte cell lines. In the present study, in order to emphasize those in vitro findings, the expression of vimentin has been investigated in cervical neoplasms of different grades, using immunohistochemistry. A clear association is reported between vimentin expression and metastatic progression, since vimentin was detected in all invasive carcinomas and lymph node metastases, but not in CIN III lesions. These in vivo results are compared with present and previous data obtained in vitro on cervical keratinocyte cell lines, where vimentin expression also correlated with in vitro invasiveness.

Animals↗
PubMed1996

Viral integration sites in human papilloma virus-33-immortalized cervical keratinocyte cell lines.

The viral organization of HPV-33 was determined by Southern blotting in 2 HPV-33-immortalized cervical cell lines (CK11 and CK12) and compared to our previous results obtained on 10 other already characterized HPV-33-immortalized cell lines (CK1 to CK10). As observed in CK1 to CK10, the viral DNA was found integrated in the cellular genome of CK11 and CK12. However, in CK11 and CK12, the integrated viral genome was deleted and mostly limited to the URR and the E6-E7 ORFs, stressing the importance of those sequences in the immortalization process. Furthermore, CK11 and CK12 showed a unique and identical integration site, as observed in CK1 to CK10, which also harbored HPV-33 integrated at a unique and identical site (which was however different from the one evidenced in CK11 and CK12). Indeed, in situ hybridizations on chromosomes allowed the precise localization of the viral DNA on chromosome 13q33-34 in CK1 to CK10 whereas it was mapped to chromosome 9p13 in CK11 and CK12. We discuss the possibility that integration of HPV-33 at those two particular sites has conferred some growth advantages to the cells and could have thus played a crucial role in the immortalization.

Cell Line, Transformed↗
PubMed1996

Membrane-type matrix metalloproteinase-1 expression at the site of human placentation.

Human trophoblast implantation is a highly regulated process of invasion that requires action of proteolytic enzymes to degrade extracellular matrix components of the endometrium. Among these enzymes, matrix metalloproteinases (MMPs) seem to be particularly important in this degradative process. We previously showed that gelatinase A is extensively expressed in vivo in the human placenta. A new MMP, MT-MMP-1 (membrane-type matrix metalloproteinase-1), which is thought to activate progelatinase A, has recently been described. In this study, we examined the expression of MT-MMP-1, by immunohistochemistry and in situ hybridization, in human placental bed biopsies taken during the first trimester of gestation. Human first trimester intermediate trophoblasts synthesized MT-MMP-1 mRNAs and the protein. The MT-MMP-1 pattern of distribution in placental beds was similar to that of gelatinase A, suggesting a pivotal role for MT-MMP-1 in placentation, perhaps by activating progelatinase A.

Blotting, Northern↗
PubMed1996

Identification of post-transplant anti-alpha 5 (IV) collagen alloantibodies in X-linked Alport syndrome.

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.

Adolescent↗
PubMed1996

Sera from patients with anti-GBM nephritis including goodpasture syndrome show heterogenous reactivity to recombinant NC1 domain of type IV collagen alpha chains.

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.

Adult↗
PubMed1995

Cell surface binding of TIMP-2 and pro-MMP-2/TIMP-2 complex.

Tissue inhibitor of metalloproteinases (TIMP-2) is a low molecular weight proteinase inhibitor capable of inhibiting activated matrix metalloproteinases (MMPs). TIMP-2 is found both free and in a 1:1 stoichiometric complex with the pro-enzyme form of MMP-2 (pro-MMP-2/TIMP-2 complex). We have measured the binding of recombinant TIMP-2 to intact HT-1080 and MCF-7 cells. HT-1080 cells in suspension bound 125I-labeled rTIMP-2 with a Kd of 2.5 nM and 30,000 sites/cell. Monolayers of MCF-7 cells were similarly found to bind [125I]rTIMP-2 with a Kd of 1.6 nM and 25,000 sites/cell. Specific binding of MMP-2 alone to HT-1080 cells was not observed; however, pro-MMP-2/TIMP-2 complex was capable of binding to the surface of HT-1080 cells in a TIMP-2-dependent manner. Binding of rTIMP-2 was not competed by the presence of TIMP-1. These results suggest that rTIMP-2 alone binds directly to the cell surface of HT-1080 and MCF-7 cell lines, and TIMP-2 is capable of localizing MMP-2 to the surface of HT-1080 cells via interaction with a specific binding site.

Cell Line↗
PubMed1995

Thrombospondin modulates human breast adenocarcinoma cell adhesion to human vascular endothelial cells.

Thrombospondin (TSP), a M(r) 450,000 cytoadhesive glycoprotein, has been shown to potentiate tumor cell metastasis in mice by a mechanism that involves the hemostatic system of the host. In this study, the potential involvement of TSP in the interaction of human mammary adenocarcinoma MCF-7 cells with human umbilical vein endothelial cells (HUVECs) in culture was investigated. Using an ELISA, preconfluent HUVECs synthesized 100-fold more TSP than did MCF-7 cells during 24 h of culture (20 versus 0.2 microgram/10(6) cells). Confocal microscopy localized TSP within intercellular junctions between aggregated MCF-7 cells in suspension. On adherent cells, TSP exhibited a patchy distribution both on the cell surface and in the cytosol. In HUVECs, TSP strongly stained the perinuclear space and was also found in association with cytoskeletal microfibrils. Flow cytometric analysis indicated the presence of a large number of unoccupied receptors for TSP on MCF-7 cells. Binding studies using [125I]TSP demonstrated the presence of 1.6 x 10(6) sites/cell with an apparent Kd of 28 nM. Attachment of radiolabeled MCF-7 cells to a TSP-coated substrate and to HUVEC monolayers was inhibited in the presence of a polyclonal antibody to TSP (10 micrograms/ml) or increasing concentrations (1-10 micrograms/ml) of soluble TSP. Neither nonimmune IgG nor the cell adhesion peptide Gly-Arg-Gly-Asp-Ser (100 micrograms/ml) inhibited these interactions. Inhibition was also observed with heparin (10 micrograms/ml), suggesting the participation of TSP heparin-binding domain(s) and heparin-like molecules. In the presence of an excess of soluble TSP or anti-TSP antibody, MCF-7 cells did not form aggregates in suspension and preformed aggregates were readily dissociated by the addition of soluble TSP. These results indicate that mammary adenocarcinoma cells use TSP to form aggregates and to attach to human endothelial cells. These interactions may have physiological implications during the hematogenous spread of tumor cells.

Adenocarcinoma↗
PubMed1995

Plasma membrane-dependent activation of gelatinase A in human vascular endothelial cells.

The initiation of the angiogenic process requires a locally confined and time-limited proteolysis of the basement membrane (BM) components at the site of new vessel sprout. Gelatinase A, a member of the matrix metalloproteinase family, degrades BM type IV collagen and is involved in the BM breakdown by migrating tumor cells and endothelial cells (EC). Gelatinase A is synthesized as latent proenzyme and must be activated in order to express its proteolytic activity. A plasma membrane-dependent mechanism of activation has been described for several tumor and transformed cells lines. In the present study, we show that latent (72 kD) and mature (62-59 kD) forms of gelatinase A are present in EC membrane fraction from Triton X-114 extract while only latent form is found in the cytosolic fraction. The incubation of EC membrane fraction with exogenous latent gelatinase A resulted in a significant activation giving rise to 62-59 kD mature forms. 12-O-tetradecanoylphorbol-13-acetate (TPA), a strong potentiator of angiogenesis in vitro and in vivo, increases the amount of both latent and activated forms of gelatinase A in EC membrane fraction as well as the ability of this latter fraction to activate exogenous latent gelatinase A. We show that the mRNA transcript coding for the membrane-integrated MMP, the MT-MMP, previously described as a potential gelatinase A activator in invasive tumor cells is also expressed in vascular EC and is regulated through a TPA sensitive process. This enzyme may be responsible for membrane-dependent gelatinase A activation in normal vascular EC and may therefore be a determinant in the control of BM proteolysis during angiogenesis.

Base Sequence↗
PubMed1995

Purification of progelatinases A and B by continuous-elution electrophoresis.

Progelatinases A and B were purified from HT1080-conditioned culture medium using a continuous-elution electrophoresis. Initially cell culture medium was ammonium sulfate precipitated. The concentrated proteins were affinity chromatographed on gelatin-Sepharose column. The bound gelatinases were eluted with electrophoresis sample buffer and subjected to continuous-elution electrophoresis. In a single run, under the standardized working conditions, the obtained fractions contained four purified enzymes--progelatinase A (M(r) 72,000), its activated forms (M(r) 62,000 and M(r) 59,000), and progelatinase B (M(r) 92,000). Moreover, the continuous-elution electrophoresis allowed the enzymes separation from their respective inhibitors--TIMP-1 (M(r) 28,500) and TIMP-2 (M(r) 21,000). The purified progelatinases A and B demonstrated high specific activities (150-200 U/micrograms).

Ammonium Sulfate↗
PubMed1995

Effects of a new oral contraceptive containing an antimineralocorticoid progestogen, drospirenone, on the renin-aldosterone system, body weight, blood pressure, glucose tolerance, and lipid metabolism.

Combined hormonal oral contraceptives (OCs) may lead to a mild rise in blood pressure and body weight. In rare instances, large increments in blood pressure are measured. We investigated the effect of a combination of ethinyl estradiol (EE) plus a progestogen with antimineralocorticoid, i.e. natriuretic, properties [Drospirenone (DRSP)] on body weight, blood pressure, the renin-aldosterone system, atrial natriuretic factor, plasma lipids, and glucose tolerance. It is anticipated that this will lead to the development of an OC that does not raise body weight or blood pressure. Four groups of 20 women each received 30 micrograms EE plus 3 mg DRSP (group A), 20 micrograms EE plus 3 mg DRSP (group B), 15 micrograms EE plus 3 mg DRSP (group C), and, as a control OC, 30 micrograms EE plus 150 micrograms levonorgestrel (Microgynon, Schering; group D) for 6 months. During the OC-free control cycles before and after treatment and throughout treatment, the target parameters were measured. Between the pretreatment cycle and the sixth treatment cycle, mean body weight fell by 0.8 to 1.7 kg in groups A, B, and C (P < 0.05 vs. D), whereas it rose by 0.7 kg in group D. Systolic and diastolic blood pressures fell by 1-4 mm Hg in groups A, B, and C (significant for A and C vs. D) and increased by 1-2 mm Hg in group D. Renin substrate rose equally in all groups (P < 0.05), whereas PRA and plasma aldosterone rose significantly only in the DRSP groups, presumably due to sodium loss. In the DRSP groups, high density lipoprotein cholesterol rose (P < 0.05), in contrast to group D. Low density lipoprotein cholesterol fell slightly (P > 0.05), whereas triglyceride levels showed a stronger increase in the DRSP groups (P < 0.05) than in group D. All groups attained good cycle control; group A had the best. Side-effects were minimal. To our knowledge, this is the first report on a combined OC that leads to a small decrease in body weight and blood pressure. It may be especially beneficial for women susceptible for a gain in weight and a rise in blood pressure.

Adolescent↗