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C Flössel

Publications and source records attributed to C Flössel.

17 recordsLinked to original sources
PubMed1999

Localization of tissue factor in actin-filament-rich membrane areas of epithelial cells.

Tissue factor (TF), the cellular receptor and cofactor for clotting factor VII/VIIa (FVII/VIIa), is known mainly as the initiator of the coagulation protease cascade. Recently, it was shown that inactivation of the murine TF gene (TF-/-) results in embryonic lethality which is most likely due to some failure of vascular integrity. On the other hand, gene disruption in mice of coagulation proteins like FVII, prothrombin, and fibrinogen results in phenotypes of embryonic development that contrast with that of TF-/-, suggesting a role for TF beyond fibrin formation in embryogenesis. In addition, there is a growing body of evidence that cellular TF may be involved in nonhemostatic functions. To determine the microtopography of membrane TF with regard to the cytoskeleton organization, we examined the expression patterns of TF and cytoskeletal proteins in various cell lines by means of double immunofluorescence and electron microscopy (EM). In spreading cells, a granular membrane TF expression of the cell cortex and a pronounced granular TF staining of microspikes, lamellipodes, and ruffled membrane areas were observed. Especially, actin and alpha-actinin were in close proximity to TF in these regions. Colocalization of TF and nonmuscle filamin (ABP-280) at the leading edge of spreading cells indicated an association of TF with the actin filament system, too. Using scanning EM we found gold-labeled TF at long processes and actin-filament-containing microspikes of neighboring cells in both branching and contact sites. By the means of immunogold EM we observed that TF is localized at the cell surface in a spotty pattern, at the base and at the top of budding processes. The observed staining pattern points to a connection of TF with elements of the cytoskeleton in these highly dynamic membrane regions, a fact which is underlined by the recently described molecular interaction of TF's cytoplasmic domain with ABP-280. In cells undergoing cytokinesis, we detected also strong TF expression in dynamic membrane areas and protrusions of the midbodies, indicating an accumulation of TF in actin-rich membrane areas with high contractile activity. In addition, we were able to demonstrate that immobilized ligands for TF, both catalytically active and inactive FVIIa or anti-TF mAbs, accelerated adhesion and spreading of TF-expressing cancer cells. Thus, our findings support the contention that ligation of cellular TF may be involved in morphogenic processes such as adhesion and spreading by an association to cytoskeletal structures. On the other hand, incubation of these cells with proteolytically active FVIIa but not with covalently inactivated FVIIa (DEGR-FVIIa) or anti-TF mAbs in solution resulted in increased motility of these cells, indicating that not only ligation of TF but also the proteolytic activity of TF-FVIIa complex is involved in cell migration.

Actin Cytoskeleton↗
PubMed1997

[Primary renal plasmacytoma. A case report].

We describe a patient with a primary renal plasmacytoma. In the literature available, only six clinical cases have been reported. A 64-year-old patient is presented who had the clinical signs of a renal cell carcinoma. Histological examination after nephrectomy, however, revealed a plasmacytoma. Based on this case, we discuss how one should proceed in this disease. Primary renal plasmacytoma can be tentatively diagnosed preoperatively only in the presence of paraproteinemia or Bence-Jones proteinuria, as it cannot be distinguished from other renal tumors by imaging procedures. Postoperatively, further staging procedures must rule out bone involvement (solitary myeloma or multiple myeloma). Nephrectomy is required in patients with plasmacytoma only if renal complications occur.

Carcinoma, Renal Cell↗
PubMed1996

Tissue factor expression during human and mouse development.

In the adult organism the cellular distribution of tissue factor (TF) expression corresponds to biological boundary layers forming a hemostatic barrier ready to activate blood coagulation after tissue injury. Whether TF expression might also play a role in development is unknown. To determine the significance of TF in ontogenesis, we examined the pattern of TF expression in mouse development and compared it with the distribution of TF in human post-implantation embryos and fetuses of corresponding gestational age. At early embryonic periods of murine (6.5 and 7.5 pc) and human (stage 5) development, there was strong expression of TF in both ectodermal and entodermal cells. In situ hybridization and immunohistochemistry demonstrated that TF mRNA and protein were expressed widely in epithelial areas with high levels of morphogenic activity during organogenesis. Staining for TF was seen during ontogenetic development in tissues such as epidermis, myocardium, bronchial epithelium, and hepatocytes, which express TF in the adult organism. Surprisingly, during renal development and in adults, expression of TF differed between humans and mice. In humans, maturing stage glomeruli were stained for TF whereas in mice, TF was absent from glomeruli but was present in the epithelia of tubular segments. In neuroepithelial cells, there was a substantial expression of TF. Moreover, there was robust TF expression in tissues such as skeletal muscle and pancreas, which do not express it in the adult. In contrast, expression of the physiological ligand for TF, factor VII, was not detectable during early stages of human embryogenesis using immunohistochemistry. The temporal and spatial pattern of TF expression during murine and human development supports the contention that TF serves as an important morphogenic factor during embryogenesis.

Adult↗
PubMed1995

Malignant neurofibroma of the urinary bladder.

We report a case of a large malignant neurofibroma of the urinary bladder occurring in a 33-year-old patient with Recklinghausen's neurofibromatosis. Urologic manifestations of neurofibromatosis are infrequent; a neurofibroma of the bladder with malignant degeneration is an extreme rarity. To date only 3 cases have been described in the literature.

Adult↗
PubMed1994

Immunohistochemical detection of tissue factor (TF) on paraffin sections of routinely fixed human tissue.

Tissue factor (TF), a 47 kDa transmembrane glycoprotein, is the essential receptor and cofactor for factor VII/VIIa. Its distribution in normal tissues and in tumours has been recently investigated immunohistochemically with monoclonal and polyclonal anti-TF antibodies in frozen sections. The cardinal problem of this technique is the difficulty of determining exactly the localization of the reaction product at least in certain tissues. Here, we demonstrate a method using monoclonal anti-TF antibodies to detect TF in routinely fixed, microwaved, paraffin-embedded tissues. Generally, there were no fundamental differences in TF distribution in frozen and paraffin-embedded material. However, in most cases, the paraffin sections allow a better cellular localization of TF. For example, the staining pattern for TF in both kinds of sections is identical in kidney, brain and skin. The paraffin-embedded material, however, clearly shows that TF expression is restricted to the parietal and the visceral epithelia of Bowman's capsule of glomeruli in the kidney, and to astrocytes and their processes in the brain. TF reactivity in the skin is revealed to be cell membrane-bound; in cardiomyocytes TF shows an exclusively sarcolemmal localization. The immunohistological detection of TF in paraffin sections is a powerful tool for systematic studies on the possible role of TF in the context of physiological and pathological studies.

Antibodies, Monoclonal↗
PubMed1994

[Demonstration and possible prognostic value of the nucleolar organizer region (NOR), the microtubule-associated proteins 1A/1B (MAP) and the intermediate filaments vimentin and cytokeratin 19 in invasive ductal breast carcinoma].

We examined the expression of the nucleolar organizer region, the microtubule-associated protein and the intermediate filaments vimentin and cytokeratin 19 and their possible value for prognosis in 51 infiltrating ductal breast carcinomas. We registered the highest NOR counts in pT2/3-tumors, in poorly differentiated breast carcinomas, in tumors with a strong MAP- and vimentin expression (this holds true for vimentin only in pT2/3-tumors). There was a relationship between areas of NOR and the differentiation degree on the one hand and the MAP- and vimentin expression on the other hand. The area of nucleolus increased with the decrease of differentiation and with the increase of vimentin expression, respectively. The expression of cytokeratin 19 showed no homogeneous relations to the traditional prognostic factors as well as to the parameters of the NOR. The area of nucleus had no prognostic value in our study. The value of the NOR is limited by its high variation. The NORs are suitable only as an adjuvant factor for the prognosis. Further studies into MAP and vimentin and their role in the prognosis of infiltrating ductal breast carcinomas appear to be important.

Age Factors↗
PubMed1993

Cellular localization of tissue factor in human breast cancer cell lines.

Expression of tissue factor (TF), the cellular receptor of clotting factor VII/VIIa, is a feature of certain malignant tumours. The TF gene has been classified as an immediate early gene responsive to serum and cytokines. Thus, the regulation of TF gene expression seems to play a role in cell growth. Recently, we have shown that constitutive TF expression in MCF-7 breast cancer cells is modulated by such growth factors as EGF, TGF alpha, and IL-1. The present study deals with the immunocytochemically detectable cellular distribution of TF in human breast cancer cell lines MCF-7 and MaTu stimulated by EGF and TGF alpha. In MCF-7 cells growing logarithmically, stimulation led to a significant increase of TF mRNA after 2 h (in situ hybridization, Northern blot) and to maximum TF expression after 6 h (immunohistochemistry). When decorated by monoclonal antibodies, TF protein showed a pronounced localization at ruffled membrane areas, cell edges, and processes of spreading cells after 6 and 20 h. In more flattened cells TF was concentrated in peripheric lamellae and microspikes communicating with neighbouring cells. After epithelial colony pattern had established, TF was predominantly accumulated at the intercellular boundaries. The vary same distribution patterns as seen in MCF-7 cells were true for the stimulated MaTu cell line.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1992

Immunohistological detection of tissue factor in normal and abnormal human mammary glands using monoclonal antibodies.

Tissue factor (TF) is the primary cell-bound initiator of the coagulation protease cascade. The cytological distribution of TF in various tissues may be described on the basis of immunohistochemistry with epitope-defined monoclonal antibodies and the extravascular distribution of TF apparently represents a haemostatic envelope ready to activate coagulation when vascular integrity is disrupted. The present study localized TF in human breast cancer tissues when compared with normal breast gland tissues and benign disorders of the mammary gland. By use of a cocktail of three epitope-defined monoclonal antibodies, TF was detected only in the myoepithelia of the resting breast gland. In proliferating disorders like fibrocystic disease or in fibroadenomas, both myoepithelia and luminal epithelia showed TF expression. Of 115 breast cancers 93 reacted with anti-TF, in an inhomogeneous manner in terms of intensity and number of positive cells. There was a tendency for more positive and intensely stained cells to be found in well-differentiated structures such as tubules. Invasive ductal carcinomas exhibiting more positive and more strongly stained cells were less commonly metastatic to lymph nodes when compared with the tumours with no detectable or very low TF immunostaining. A semi-quantitatively recorded score of TF immunostaining correlated with the procoagulatory activity measured (7 fibroadenomas and 24 carcinomas). The results of this study suggest that proliferation and differentiation of the mammary gland is associated with enhanced TF expression in the epithelia which are negative for TF staining in the resting gland. Malignant growth is characterized by randomly expressed epithelial TF, which expression is enhanced and more frequent in well-differentiated tumour cells.

Antibodies, Monoclonal↗
PubMed1992

Constitutive tissue factor expression of human breast cancer cell line MCF-7 is modulated by growth factors.

Expression of tissue factor, the initiator of the extrinsic coagulation protease cascade, is a feature of certain malignant tumours. To study the modulation of tissue factor expression we incubated the breast cancer cell line MCF-7 with several growth factors. Epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha) and interleukin-1 (IL-1) rapidly increased tissue factor expression of MCF-7 cells peaking at 6-8 h after starting point of incubation, as determined by clotting test, enzyme linked immunosorbent assay and flow cytometry. The data presented support the hypothesis that modulation of constitutive tissue factor expression in tumour cells by TGF alpha and IL-1 could also occur in vivo possibly resulting from interactions of stromal and cancer cells. The meaning for tumour biology, however, remains unclear.

Blood Coagulation Tests↗
PubMed1992

An ELISA for tissue factor using monoclonal antibodies.

Whereas tissue factor, a high-affinity cell-surface receptor and essential cofactor for the serine protease factor VII is constitutively present in certain tissues such as epithelial tissue, brain and placenta, it is not normally expressed by cells within the vasculature. However, the stimulation of monocytes and endothelial cells by a variety of inflammatory and immunological reactions results in the induction of cell surface tissue factor (TF) expression. TF is also expressed on tumour cells, and may play a role in tumour growth and metastasis formation. To examine the role of TF in these processes we developed monoclonal antibodies to human tissue factor apoprotein. The antibodies were characterized by neutralization of the procoagulant activity and by immunoblotting. With two of these monoclonal antibodies a sandwich ELISA was developed for the rapid quantitation of TF. The sensitivity of the assay permits extensive studies involving the modulation of TF expression on small numbers of cells. The results are comparable to the functional clotting assay as evaluated with unpurified TF and with the tumour cell line MCF-7. For certain applications, monitoring of cellular TF expression by ELISA using anti-TF monoclonal antibodies is preferable because it is not influenced by other coagulation factors or by inhibitors of procoagulant activity on the cells.

Animals↗
PubMed1990

Flow cytometric analysis of tissue factor (TF) expression on stimulated monocytes--comparison to procoagulant activity of mononuclear blood cells.

Whereas tissue factor (TF), a 47 kDa transmembrane glycoprotein, is constitutively present in certain tissues such as epithelial tissue, brain, and placenta, it is normally not expressed by cells within the vasculature. However, inflammatory mediators including bacterial lipopolysaccharide (LPS) can stimulate the expression of cell surface procoagulant activity (PCA) on monocytes. In our present study the kinetics (over 24 h) of molecular TF expression on LPS-stimulated monocytes analyzed by flow cytometry corresponds closely to functional PCA of human mononuclear blood cells (MBC). Both PCA and TF expression on monocytes were rapid events reaching their maximum after about 6 h of stimulation. At this time approximately 70-80% of monocytes had also achieved maximum anti-TF MAb receptor density. For certain analytical applications, monitoring of molecular TF expression on monocytes by flow cytometry using anti-TF MAb is favorable because there is no influence by PCA inhibitors.

Antibodies, Monoclonal↗
PubMed1987

Procoagulant activity of human mononuclear blood cells (MBC). Stimulation by concanavalin A and mixed MBC culture.

Human mononuclear blood cells (MBC) express procoagulant activity PCA) upon stimulation in vitro. This thromboplastin activity is generated in monocytes under the influence of T-helper cell-derived signals. The own experiments described here served to establish the methodological basis for human MBC PCA generation in vitro and its measurement. Using Con A as stimulant it was shown that maximum PCA could be detected after 6-8 h of incubation. Incubation of the cells at 37 degrees C resulted in much higher PCA as compared to 40 degrees C. But in most experiments the specific differences between unstimulated controls and the Con A treated cells were more marked at 40 degrees C, because the "spontaneous" activation of controls occurred more slowly. The "spontaneous" activation of controls has been the most troublesome problem throughout the experiments, and was most likely due to traces of endotoxin in the media used. Choosing an incubation temperature of 40 degrees C it was shown that neither glass-adherent (AC) nor non-adherent cells (NAC) responded sufficiently to Con A when incubated separately. Addition of NAC to AC restored the capability to respond to Con A. NAC pulse-stimulated with Con A were able to activate AC. The same has been true for 20 h incubation supernatants of Con A-pulsed NAC. Finally, some two-way MBC mixed culture experiments are described which have been conducted under apparently endotoxin-free conditions. These results clearly show cellular PCA generation to be a sensitive indicator of allogenic recognition.

Blood Coagulation Factors↗
PubMed1984

[Procoagulatory activity of macrophages and monocytes of the guinea pig].

Guinea pig peritoneal macrophages and blood monocytes possess a membrane-bound tissue factor-like procoagulant activity. This activity can be induced to grow by mitogenic lectins and by lymphocyte products released specifically upon contact with immunizing antigens in vitro. The procoagulant activity can be easily measured by a plasma recalcification test. Guinea pig peritoneal cells and mononuclear blood cells from animals immunized with ovalbumin, bovine gamma-globulin or tetanus vaccine reacted to the corresponding antigen in a specific manner by expression of increased amounts of procoagulant activity (ovalbumin: + 16.9%; bovine gamma-globulin: + 26.8%, tetanus vaccine: + 23.5%). Supernatants from peritoneal cells were active in transferring the stimulus to neutral peritoneal cells which expressed thereafter higher amounts of procoagulant activity.

Animals↗