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S Garbisa

Publications and source records attributed to S Garbisa.

At least 73 records · Page 4Linked to original sources
PubMed1987

Secretion of type IV collagenolytic protease and metastatic phenotype: induction by transfection with c-Ha-ras but not c-Ha-ras plus Ad2-E1a.

Activated ras oncogene transfection into suitable recipient cells has been shown to induce the metastatic phenotype (Thorgeirsson, et al., Mol. Cell. Biol., 5: 259-262, 1985). We have used this model system to study the correlation of basement membrane collagenolysis with metastatic propensity. The c-Ha-ras oncogene alone, or combined with v-myc, transfected into early passage rat embryo fibroblasts, induce these cells to secrete high levels of type IV collagenolytic metalloproteinase and to concomitantly exhibit a high incidence of spontaneous metastases in nude mice. Cotransfection of c-Ha-ras plus the adenovirus type 2 E1a gene yields cells which are highly tumorigenic but nonmetastatic and fail to produce type IV collagenase. This effect is due to a suppression of collagenase elaboration, not increased production of a collagenase inhibitor, and not decreased production of a collagenase activator. The characteristics of the collagenase are identical to tumor type IV collagenase described previously. The nonmetastatic cells which failed to produce type IV collagenase retain the ability to secrete high levels of plasminogen activator. Transfection with the protooncogenic forms of Ha-ras or mos, or spontaneous transformation of NIH 3T3 cells or chemical transformation of BALB 3T3 cells yields cells which fail to produce collagenase, are tumorigenic, but totally nonmetastatic. These data support a biochemical linkage of type IV collagenase expression with the metastatic phenotype in this rodent system.

Adenovirus Early Proteins↗
PubMed1987

Hepatocellular carcinoma: expression of basement membrane glycoproteins. An immunohistochemical approach.

The identification and characterization of collagenous and non-collagenous glycoproteins have made it possible to use specific antibodies as tools for the topographical localization of the various connective tissue components, and thus to follow the progression of parenchymal-stromal interactions. This investigation is an approach to the study of in vivo relationships between basement membrane components (type IV collagen, laminin) and neoplastic cells of hepatocellular carcinoma. Ten cases of hepatic carcinomas were analysed and paraffin-embedded sections were immunostained with anti-laminin and anti-type IV collagen antibodies. The avidin-biotin-peroxidase complex technique was used. In well differentiated neoplasms with hepatic tumour cells organized in a trabecular pattern lined by sinusoid structures, type IV collagen was always detected at the sinusoidal level. Laminin was evident only in two cases with a prominent intraparenchymal vascular bed. In less differentiated neoplasms, sinusoids were almost absent and only large tumour vessels were positive for both laminin and type IV collagen. At the interface between tumour tissue and the surrounding stroma, some carcinomatous elements were surrounded by laminin and type IV collagen. Our data further support the hypothesis that basement membrane phenotypic expression may be influenced both by the degree of tumour differentiation and by the characteristics of the micro-environment.

Basement Membrane↗
PubMed1987

The use of reverse-phase high-performance liquid chromatography and precolumn derivatization with dansyl chloride for quantitation of specific amino acids in collagen and elastin.

A rapid and accurate reverse-phase high-performance liquid chromatography procedure for amino acid analysis of connective tissue proteins has been optimized. The method is based on quantitative dansyl chloride precolumn derivatization of protein hydrolyzates and chromatographic separation of the dansyl derivatives on Ultrasphere ODS C18 column. High molar uv absorption of Pro and Hyp derivatives, quantitation of low Des and Ide amounts (60 pmol), and good separation of all the amino acid derivatives (CV mostly less than 0.1%) including Hyl overcome the difficulties of other methods in producing reliable single run amino acid analysis of collagen and elastin. The use of fluorescence detector and the possibility of concentrating derivatized samples would give even higher sensitivity to the system. The procedure appeared to be suitable for single run analysis of other proteins, particularly those having an unbalanced amino acid composition.

Amino Acids↗
PubMed1987

Primary liver cell carcinoma. New insight for a more correct approach to its classification.

Hepatocellular carcinomas, cholangiocellular carcinomas, and "indeterminate" forms have been studied by immunohistochemical detection of several antigens: alpha-fetoprotein and CEA, as well as type IV collagen, laminin, and keratin. While the first two antigens were variably detectable in different samples, in the poorly differentiated areas of hepatocellular carcinoma type IV collagen and laminin were both absent. These basement membrane glycoproteins constantly surrounded the cholangiocellular carcinoma tubular structures and were always present in those areas of the "indeterminate" group where the cells were organized as pseudoglandular or ductular aggregates. Keratin was absent in all cases of hepatocellular carcinoma, was variably detectable in the "indeterminate" neoplasms and was always present in cholangiocellular tumors. The neoplasias with mixed histopathological features usually showed morphological and biochemical biliary differentiation at the periphery, in contact with the collagenous stroma. We postulate that in some cases hepatocarcinoma cells undergo metaplastic transformation giving rise to cholangiocellular forms. Type IV collagen, laminin, and keratin seem to be accurate markers of phenotypical differentiation and show that a continuous phenotypical spectrum exists between hepatocellular and cholangiocellular entities.

Adenoma, Bile Duct↗
PubMed1987

Immunohistochemical study of basement membrane antigens in bronchioloalveolar carcinoma.

Bronchioloalveolar carcinoma (BAC), not yet completely defined as a biologic entity, has recently been classified into two different types. Immunohistochemical investigations, aimed at characterizing basement membrane (BM) behavior in the two types of BAC, revealed different distribution patterns. The first (Type I BAC) showed a linear staining for laminin and Type IV collagen similar to normal lung. Fibronectin was widely present in the septal interstitium and patchily distributed along the BM. The second (Type II BAC) showed a variable reaction for Type IV collagen and fibronectin, whereas laminin was absent or appeared as short, interrupted tracts around the epithelial neoplastic population, similar to conventional adenocarcinoma of the lung. These results suggest that only Type I BAC shows structural characteristics different from those of conventional adenocarcinoma of the lung.

Adenocarcinoma↗
PubMed1986

Transient expression of type IV collagenolytic metalloproteinase by human mononuclear phagocytes.

A type IV collagenolytic metalloproteinase secreted by human monocytes/macrophages has been isolated and characterized. Monocytes isolated from peripheral blood and cultured in vitro exhibited a high type IV collagenolytic activity during the first and second day, but such activity declined markedly over subsequent days. Type IV collagenolytic activity was also transiently elaborated by macrophages isolated from (a) bronchioalveolar lavage of patients with pulmonary sarcoidosis, (b) primary human colostrum, and (c) peritoneal lavage of a patient with peritonitis. In contrast, macrophages isolated from the bronchioalveolar lavage of normal individuals, or from noninflammatory peritoneal fluids, failed to exhibit type IV collagenolytic activity. A type IV collagenolytic neutral proteinase was purified from macrophages isolated from inflammatory peritoneal fluid. The proteinase has a mass of 67 kDa on gel electrophoresis and is not altered in its migration under reducing conditions. It produces a characteristic 1/4-3/4 cleavage of type IV collagen, and its activity is abolished by treatment with EDTA but not phenylmethanesulfonyl fluoride. The isoelectric pH of the proteinase is 5.2 as judged by two-dimensional gel electrophoresis. The amino acid composition of the proteinase was notable for a high content of serine, glutamic acid, glycine, and alanine and no detectable hydroxyproline, cysteine, or methionine residues. The carbohydrate content of the proteinase was 11.2%, and galactose was the most abundant monosaccharide (8.7%) released following acid hydrolysis, followed by glucose (1.3%), mannose (1.2%), and trace amounts of fucose and galactosamine. Such a type IV collagenolytic protease may play an important role during the traversal of the vascular basement membrane by extravasating monocytes. The biochemical characteristics and biologic function of the macrophage proteinase may be similar or identical to the type IV collagenolytic proteinase identified in metastatic tumor cells.

Adult↗
PubMed1986

Behaviour of basement membrane antigens in gastric and colorectal cancer. Immunohistochemical study.

Eighty gastric and colorectal lesions including cases of dysplasia and carcinoma were studied by immunohistochemical techniques to investigate the behaviour of laminin, type IV collagen and fibronectin. Their distribution was examined on frozen and formalin-fixed, paraffin-embedded samples. In the same lesions, interruption, fragmentation and absence of basement membrane (BM) antigen-staining were observed. Carcinomas with well differentiated glandular structures were always surrounded by a well defined BM as in normal, non-pathological tissues. On the contrary, undifferentiated areas arranged in nests or sheets were usually negative for laminin and type IV collagen. Anomalous BM staining was strictly related to the degree of differentiation of tumor tissue, while no correlation existed between carcinoma staging and BM antigen presence, either in gastric or colorectal neoplasms. Immunostaining with antibody against type IV collagenase showed a massive positivity in the early gastric carcinomas examined, while in colorectal cancer only granulocytes showed it.

Antigens↗
PubMed1986

Detection of extracellular matrix antigens (fibronectin, laminin, type IV in collagen) in paraffin embedded sections by avidin-biotin-peroxidase complex labelling.

An avidin-biotin-peroxidase labelling method was applied to frozen sections and to routine-fixed, paraffin-embedded sections, and compared with immunohistochemical results of stromal antigen detection (type IV collagen, laminin and fibronectin) obtained in parallel on different neoplasias. Lung, breast and gastrointestinal tract tumors were studied. Superimposable sections were obtained from cryostat and formalin-fixed, paraffin-embedded specimens (previously digested by pepsin). The data demonstrate the potential use of immunohistochemical investigation of paraffin-embedded tissues for histological analyses of tumors.

Avidin↗
PubMed1985

Sequential behaviour of extracellular matrix glycoproteins in an experimental model of hepatic fibrosis.

The behaviour of extracellular matrix glycoproteins (fibronectin, laminin, basement membrane heparan-sulphate proteoglycan, type III, IV and V collagens) has been investigated in a sequential model of experimental hepatic fibrosis, using an immunofluorescence technique. The presence of some basement membrane macromolecules (such as type IV and V collagens, laminin and basement membrane heparan-sulphate proteoglycan) is detectable only in the early stages of septa formation, while type III collagen and fibronectin persist in late septa. These data suggest that hepatic fibroplasia proceeds through different steps in which stromal glycoproteins are preferentially engaged, as happens during organogenesis.

Animals↗
PubMed1984

Macromolecular organization and functional architecture of basement membranes.

Basement membranes (BMs) are extracellular laminar matrices produced by endothelial and epithelial cells. They are composed by three major intrinsic macromolecules: type IV collagen, laminin and heparan sulfate proteoglycan (HSP), and by two major extrinsic ones: fibronectin and type V collagen. The intrinsic components are assembled in a three-dimensional network (type IV collagen) to which cells stick (by laminin) and through which (HSP) they interact with the stromal compartment. The BM is a barrier to be crossed by any cell that leaves the stroma to enter into the circulation or vice versa. Metastatic tumor cells secrete a protease which specifically degrades the BM collagen and some evidence suggests that the same enzyme is used also by normal monocytes.

Animals↗
PubMed1983

Basement membrane collagen: degradation by migrating endothelial cells.

One of the first steps in neovascularization is dissolution of the basement membrane at the point of endothelial outgrowth. An assay was developed to determine whether basement membrane collagens (types IV and V) are degraded by endothelial cells migrating toward a chemotactic stimulus. Fetal bovine endothelial cells were placed on one side of a filter containing the collagen substrate, and a chemoattractant derived from retinal extracts was placed on the opposite side. Degradation of both type IV and type V collagens was observed when the retinal factor was placed on the side of the filter opposite the endothelial cells. Metalloproteinases that cleaved type IV and type V collagens could be extracted from the endothelial cells with detergents. Such endothelial cell-associated (possibly membrane-bound) proteinases may locally disrupt the basement membrane and facilitate the outgrowth of capillary sprouts toward the angiogenic stimulus.

Animals↗
PubMed1983

Degradation of basement membrane components by vascular endothelial cells: role in neovascularization.

A retina-derived substance (or substances) has been identified that stimulates vascular endothelial cells to degrade three structural components of basement membrane: type IV collagen, fibronectin and laminin. In basement membrane surrounding existing blood vessels, endothelial cells stimulated in this way can presumably migrate through the resulting gaps and form new vascular sprouts. These events may therefore represent the earliest steps in the formation of new blood vessels.

Animals↗
PubMed1982

Role of collagenases in tumor cell invasion.

Collagenases are a family of metalloproteinases which may play a role in facilitating tumor cell invasion of the extracellular matrix. Tumor cells traverse two types of extracellular matrix: basement membranes and interstitial stroma, at multiple stages of the metastatic process. The matrix is a dense meshwork of collagen, proteoglycans, elastin and glycoproteins. Normally the matrix does not contain open spaces large enough for cell movement. Therefore numerous investigators have postulated that collagenolytic proteases, secreted by tumor cells or associated host cells, breakdown the extracellular matrix during tumor cell invasion. A large number of animal and human tumors have been shown to contain collagenase at a higher level than corresponding benign tissues. Separate collagenolytic metalloproteinases have been identified which degrade specific types of collagen. A basement membrane collagenolytic protease was shown to be elevated in a series of metastatic murine tumor cells. Immunologic studies using antibodies specific for collagenase have demonstrated that in vivo, tumor cells can produce collagenase. Therefore identification of collagenase in cultured lines of tumor cells is not an artifact of in vitro cultivation. In some cases, tumor cells may induce host cells to produce collagenase. The best evidence to date that collagenases actually play a role in invasion is derived from experiments in which natural collagenase inhibitors block tumor cell invasion of extracellular matrix in vitro.

Animals↗