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W Stetler-Stevenson

Publications and source records attributed to W Stetler-Stevenson.

17 recordsLinked to original sources
PubMed2000

Pentosan polysulfate decreases proliferation and extracellular matrix deposition by vascular smooth muscle cells isolated from failed hemodialysis access grafts.

BACKGROUND: Vascular access failure is a major cause of morbidity, and increased costs in patients undergoing maintenance hemodialysis. Stenosis, the most common underlying cause of loss of patency in failed grafts, appears to be caused by an obstructing mass of tissue containing proliferating smooth muscle cells and their associated extracellular matrix. METHODS: To determine whether this process was amenable to pharmacologic intervention and/or prevention, we obtained samples of the material occluding vascular accesses from 7 patients undergoing revision surgery in order to characterize the cells contributing to the stenosis. In all 7 patients the outgrowth contained predominantly smooth muscle-like cells admixed with fibroblasts, which produced a large amount of type IV and type I collagen. RESULTS: Treatment with pentosan polysulfate inhibited cell proliferation and significantly reduced the accumulation of types I and type IV collagens. This was associated with increase in metalloproteinase-9 (MMP-9) and a shift of tissue inhibitor of metalloproteinase-3 (TIMP-3) from the cell layer into the medium. CONCLUSION: These data suggest that pentosan polysulfate (PPS) may have a favorable effect in patients with a polytetrafluoroethylene (PFTE) graft by decreasing cell proliferation and collagen deposition.

Blood Vessel Prosthesis↗
PubMed2000

High preoperative plasma tissue inhibitor of metalloproteinase-1 levels are associated with short survival of patients with colorectal cancer.

The objective of the present study was to measure preoperative plasma tissue inhibitor of metalloproteinase (TIMP)-1 levels in colorectal cancer patients and relate these values to clinical and biochemical patient characteristics. TIMP-1 levels were determined by ELISA in EDTA plasma samples collected preoperatively from 588 colorectal cancer patients. Plasma TIMP-1 levels were distributed with a median value of 141.1 microg/liter (range, 53.7-788.7 microg/liter). Whereas no significant differences were found in the median plasma TIMP-1 levels among patients with Dukes' stage A, B, and C disease, patients with Dukes' stage D disease had significantly higher plasma TIMP-1 levels (P < 0.0001); however, high plasma TIMP-1 levels were not restricted to advanced disease. A relatively weak correlation between plasma TIMP-1 level and age was found (r = 0.35; P < 0.0001). There was no significant difference in TIMP-1 levels between males and females (P = 0.97). Univariate analysis demonstrated an increasing risk of mortality with increasing TIMP-1 levels [scored as the log(e)(TIMP-1); hazard ratio = 3.3; 95% confidence interval, 2.6-4.2; P < 0.0001]. Including covariates (Dukes' stage, primary tumor location, gender, age, plasminogen activator inhibitor type 1, and soluble urokinase plasminogen activator receptor) in a multivariate analysis, TIMP-1 was retained in the final model (hazard ratio = 2.5; 95% confidence interval, 1.7-3.7; P < 0.0001). This study showed a highly significant association between preoperative plasma TIMP-1 levels and survival in colorectal cancer patients, with higher plasma TIMP-1 levels being associated with poor outcome. Independent of clinical parameters including Dukes' stage, plasma TIMP-1 levels were found to strongly predict prognosis of colorectal cancer patients. Additional studies are needed to validate the clinical usefulness of plasma TIMP-1 measurements.

Adult↗
PubMed1998

Adenovirus-mediated gene transfer of the human tissue inhibitor of metalloproteinase-2 blocks vascular smooth muscle cell invasiveness in vitro and modulates neointimal development in vivo.

BACKGROUND: Endovascular injury induced by balloon withdrawal leads to the increased activation of matrix metalloproteinases (MMPs) in the vascular wall, allowing smooth muscle cells (SMCs) to digest the surrounding extracellular matrix (ECM) and migrate from the media into the intima. The objective of this study was to examine the effects of a replication-deficient adenovirus carrying the cDNA for human tissue inhibitor of metalloproteinase-2 (AdCMV.hTIMP-2) on SMC function in vitro and neointimal development in the injured rat carotid artery. METHODS AND RESULTS: Infection of cultured rat aortic SMCs at a multiplicity of infection of 100 with AdCMV.hTIMP-2 resulted in high-level expression of hTIMP-2 mRNA and protein secretion into the medium. Conditioned media (CM) from AdCMV. hTIMP-2-infected but not control virus (AdCMV.null or AdCMV. betagal)-infected SMCs inhibited MMP-2 activity on gelatin zymograms as well as the chemoattractant-directed migration of SMCs across reconstituted basement membrane proteins in the Boyden chamber assay. In contrast, AdCMV.hTIMP-2 CM had no effect on chemoattractant-directed migration of SMCs occurring in the absence of an ECM barrier or on the proliferation of cultured neointimal SMCs. Delivery of AdCMV.hTIMP-2 (2.5x10(9) pfu) to the carotid artery wall at the time of balloon withdrawal injury inhibited SMC migration into the intima by 36% (P<0.05) at 4 days and neointimal area by 53% (P<0.01) at 8 days and by 12% (P=NS) at 21 days after injury. AdCMV.hTIMP-2 had no effect on medial area. CONCLUSIONS: Adenovirus-mediated hTIMP-2 gene transfer inhibits SMC invasiveness in vitro and in vivo and delays neointimal development after carotid injury.

Adenoviridae↗
PubMed1995

Elevated tissue inhibitor of metalloproteinase 1 RNA in colorectal cancer stroma correlates with lymph node and distant metastases.

Tissue inhibitor of metalloproteinase (TIMP) inhibits the proteolytic activity of several matrix metalloproteinases centrally involved in tumor invasion and metastases. The purpose of this study was to determine the origin of TIMP-1 mRNA production in both human colorectal cancer (CRC) and metastatic liver lesions as well as define the relationships between TIMP-1 RNA expression and standard clinicopathological variables of CRC. Total cellular RNA, extracted from 56 CRC and 10 liver metastases, were examined by Northern blot hybridization. The mean/normal mucosa fold increase of TIMP-1 RNA was significantly elevated in both CRC (12.1 +/- 1.7) and liver metastases (10.0 +/- 3.6). No relationship was noted between TIMP-1 expression and tumor size, location nor differentiation. Based on lymph node metastases status, significantly higher TIMP-1 RNA levels were found in CRC with metastases than in those without metastases (15.6 +/- 3.3 versus 7.9 +/- 1.3) (P = 0.04). Similarly, TIMP-1 RNA levels were higher in primary CRC with distant metastases than those without distant metastases (17.6 +/- 4.1 versus 9.3 +/- 1.9) (P = 0. 04). In situ hybridization localized TIMP-1 mRNA predominantly in tumor stroma within spindle fibroblast-like cells rather than in cancer cells themselves. The correlation between the increased TIMP-1 mRNA level and advanced CRC stage noted in this study reflects a possible growth-promoting function for TIMP-1 in human CRC.

Aged↗
PubMed1992

Expression of matrix metalloproteinase genes in transformed rat cell lines of high and low metastatic potential.

The enzymes that comprise the family of matrix metalloproteinases (MMPs) share the capacity to degrade extracellular matrix components. A large body of evidence indicates that certain members of this metalloproteinase gene family play critical roles in determining the malignant phenotype of solid tumors. We previously have derived transformed cell lines with vastly different metastatic potentials by transfecting different combinations of oncogenes into primary rat embryo cells. Conditioned medium from those cell lines was assayed by Western blot analysis for the production of four separate matrix metalloproteinases to see whether a correlation could be found between protease expression and the metastatic phenotype. The transformed rat embryo cell lines with high metastatic potential were found to produce high levels of the stromelysin 1 (MMP-3) and stromelysin 2 (MMP-10) proteases, while the nonmetastatic lines produced low or undetectable levels of these two enzymes. No correlation was seen between the metastatic phenotype of the cell lines and the level of expression of two other matrix metalloproteinases, the M(r) 72,000 type IV collagenase (MMP-2) and the M(r) 92,000 gelatinase (MMP-9). These data suggest that the differential regulation of the stromelysin proteases may contribute to the difference seen in the metastatic potential of these cell lines.

Animals↗
PubMed1992

Immunoassay of type IV collagenase/gelatinase (MMP-2) in human plasma.

We have developed a sensitive and specific sandwich type enzyme-linked immunosorbent assay (ELISA) to detect type IV collagenase (MMP-2) in human plasma which employs the combination of affinity purified rabbit polyclonal antibodies and mouse monoclonal antibodies to human MMP-2. The MMP-2 ELISA detects latent and activated MMP-2, MMP-2 complexed with TIMP and MMP-2 complexed with alpha 2 macroglobulin (65% efficiency). To determine whether physiologic conditions associated with increased connective tissue turnover are accompanied by increased MMP-2 levels in plasma, we compared enzyme levels in pregnant and nonpregnant women. Plasma MMP-2 (mean +/- standard deviation) was significantly increased (p less than 0.05) in the second half of pregnancy (650 +/- 312) as compared to early pregnancy (356 +/- 139) or the nonpregnant state (387 +/- 193). As a result of the linkage between type IV collagenase production by cancer cells and the metastatic phenotype, the assay of MMP-2 in plasma is of potential clinical value in cancer.

Antibodies, Monoclonal↗
PubMed1992

Distribution of the 72-kd type IV collagenase in nonneoplastic and neoplastic thyroid tissue.

The 72-kd type IV collagenase (matrix metalloproteinase-2 [MMP-2]) is a neutral metalloproteinase that initiates the degradation of type IV collagen in basement membranes. Its production by tumor cells has been correlated with the invasive and metastatic potential of neoplasms. Two recently developed affinity-purified antibodies against synthetic peptides from the amino terminus (H1) and an internal domain (Ab48) of the molecule were used to investigate immunohistochemically the distribution of this enzyme in a variety of thyroid tissues. All primary carcinomas (20 papillary, seven follicular, and three medullary) as well as nine of 11 metastases were positive, with the more aggressive tumors (tall cell variant of papillary carcinomas and invasive follicular carcinomas) tending to be more reactive than the low-grade tumors (classic and microinvasive papillary carcinomas and minimally invasive follicular tumors). Negative or minimal positivity was found in six cases of normal thyroid, one goiter, and two cases of Graves' disease. Immunoreactive follicular cells were seen focally in areas of inflammation, fibrosis, and distortion of normal follicles, and in Hashimoto's thyroiditis (four cases). Five of nine adenomas showed positive cells, but this could be related to previous trauma to the area. We conclude that there is increased production of the 72-kd type IV collagenase (MMP-2) in thyroid cancer; however, this enzyme also is elevated in benign conditions that are undergoing remodeling and repair.

Adenocarcinoma↗
PubMed1992

Expression of type IV collagenase correlates with the invasion of human lymphoblastoid cell lines and pathogenesis in SCID mice.

An in vitro model, called the Membrane Invasion Culture System (MICS), was used to study the invasive potential of an Epstein-Barr virus (EBV) positive lymphoblastoid cell line (LCL), an EBV-negative Burkitt lymphoma (BL) cell line of American origin and an EBV-positive BL of African origin. MICS measured the ability of these cell lines to invade reconstituted basement membrane-coated filters, which correlated with their tumorigenic and metastatic capabilities in a SCID mouse model. Furthermore, the significantly greater invasive behaviour of the EBV-positive LCL was directly correlated with the cells' ability to express and secrete human type IV collagenase (72 kDa), an important metalloproteinase responsible for the degradation of collagen IV in basement membranes. The data suggest that MICS and the SCID mouse are useful tests of tumorigenicity in lymphoid cells, with measurable effects in both systems related to human type IV collagenase activity. Both models allow further exploration of malignant phenotypes associated with EBV transformation of lymphoid tissues.

Animals↗
PubMed1992

Characterization of metalloproteinases and tissue inhibitors of metalloproteinases in human plasma.

In this study, we have identified and characterized metalloproteinases and tissue inhibitors of metalloproteinases (TIMPs) in human plasma. Treatment of plasma with trypsin or aminophenylmercuric acetate resulted in activation of latent gelatinolytic activity. Fractionation of plasma by gelatin Sepharose chromatography resulted in the isolation of 72 kDa and 92 kDa gelatinases/type IV collagenases. The 72 kDa gelatinase was purified by gel filtration chromatography. Stromelysin-1 was isolated from plasma by Matrex green A affinity chromatography. Immunoblotting of plasma fractions with antibodies to unique peptide regions of human gelatinases differentiated the 72 kDa gelatinase from the 92 kDa gelatinase. Antibodies to the amino terminal peptides of each enzyme were used to determine that plasma gelatinases circulate as latent proenzymes. Immunoblotting with antibodies directed against human stromelysin identified a 57 kDa stromelysin. TIMP-1 (28 kDa) and TIMP-2 (21 kDa) were also identified by immunoblotting of gelatin Sepharose bound plasma proteins using non-crossreacting antibodies to each protein.

Amino Acid Sequence↗
PubMed1992

Immunohistochemical profile of basement membrane proteins and 72 kilodalton type IV collagenase in the implantation placental site. An integrated view.

An immunohistochemical study was performed to investigate the interactions between trophoblast and the extracellular matrix in the implantation site of early pregnancies. Two basement membrane-related proteins (type IV collagen and laminin), as well as the expression of the 72 kilodalton type IV collagenase, were studied with affinity-purified antibodies. human placental lactogen, human chorionic gonadotropins, and AE1/AE3 cytokeratins were used to identify the different cell populations involved in the implantation process. All types of trophoblastic cells, from villous cells to the different types of intermediate trophoblast, expressed the 72 kilodalton type IV collagenase. Decidual cells, Hofbauer's cells, villous fibroblasts, and amnion were also positive. Laminin and type IV collagen were expressed in all basement membranes, including large decidual and intermediate trophoblast cells, and the villous stroma. Nitabuch's layer, an acellular degradative zone at the site of initial attachment, showed positivity for type IV collagen. The extracellular matrix in the implantation site seems to be a meshwork of, among other components, laminin and type IV collagen, in which the invading trophoblastic cells are embedded. The invasive capacity of these cells in vivo may be, at least in part, mediated by their type IV collagenolytic activity along with that of the decidual cells, thus regulating the permeability of the extracellular matrix.

Amino Acid Sequence↗
PubMed1990

Placental site trophoblastic tumor associated with immature ovarian teratoma.

This paper describes a woman who developed three malignancies within a very short time. Two of these, immature teratoma and placental site trophoblastic tumor, were rare gynecological neoplasms. The third was a breast carcinoma. This is the first report of an association of placental site trophoblastic tumor with a primary germ cell tumor of the ovary.

Adult↗
PubMed1988

Monoclonal antibodies to type IV collagenase recognize a protein with limited sequence homology to interstitial collagenase and stromelysin.

Type IV collagenase is a metalloproteinase associated with metastatic tumor cells. It specifically cleaves the triple helical basement membrane (type IV) collagen molecule at a single site. Monoclonal antibodies which block the activity of the human type IV collagenase were developed and used to purify this antigen. The purified type IV collagenase was partially sequenced following cyanogen bromide and trypsin cleavage. The amino acid sequence of the human type IV collagenase fragments revealed a region homologous to the human interstitial collagenase and stromelysin. However, several sequences in type IV collagenase were identified which are distinct from the latter. Polyclonal antibodies were raised against a synthetic peptide derived from such a sequence. Following affinity purification, the antibodies recognized the denatured human type IV collagenase in Western immunoblotting. These data indicate that type IV collagenase is a distinct member of a general family of metalloproteinases.

Amino Acid Sequence↗
PubMedDate not supplied

Increased expression of membrane-type matrix metalloproteinase and preferential localization of matrix metalloproteinase-2 to the neointima of balloon-injured rat carotid arteries.

BACKGROUND: Remodeling of the injured vascular wall is dependent on the action of several extracellular proteases. Previous studies have shown that expression of matrix metalloproteinases (MMP-2 and MMP-9) is upregulated after vascular injury and that MMP-2 is required for the migration of cultured vascular smooth muscle cells across complex extracellular matrix barriers. The present study examined changes in the expression of membrane-type metalloproteinase (MT-MMP-1), a putative regulator of MMP-2, in the tissue localization of MMP-2, and in the expression of activated and latent forms of MMP-2 and the tissue inhibitor of metalloproteinases, TIMP-2, in rat carotid arteries subjected to balloon catheter injury. METHODS AND RESULTS: MT-MMP-1 mRNA levels increased sixfold after 3 days of injury, coinciding with an increase in MMP-2 activation assessed by gelatin zymography. Western blotting and gelatin zymography showed an increase in MMP-2 protein levels beginning 5 to 7 days after injury; immunocytochemistry and Western blotting showed that the increase occurred preferentially in the developing neointima. CONCLUSIONS: These results show that increased expression of MT-MMP-1 and activation of MMP-2 occurs early after injury to the rat carotid artery and that at later times MMP-2 is preferentially localized to the developing neointima.

Angioplasty, Balloon↗
PubMedDate not supplied

Type IV collagenase/gelatinase (MMP-2) is not increased in plasma of patients with cancer.

We have developed a sensitive and specific sandwich-type enzyme-linked immunosorbent assay to detect M(r) 72,000 type IV collagenase [matrix metalloproteinase 2 (MMP-2)] in human plasma. As a result of the linkage between MMP-2 production by cancer cells and the metastatic phenotype, we undertook this study to compare plasma MMP-2 levels in healthy individuals, patients with various types of cancer, and hospitalized patients with chronic diseases other than cancer. The results demonstrate that MMP-2 levels are not increased in cancer patients regardless of the extent of disseminated malignancy. In an effort to explain this data, we compared MMP-2 secretion by human umbilical vein endothelial cells and lung cancer cells passaged as cell lines. Endothelial cells secreted higher levels of MMP-2 than did lung cancer cells propagated in vitro. We propose that blood vessel lining cells make a sizable contribution to plasma levels of MMP-2 and may thereby obfuscate the detection of increased levels of MMP-2 originating from extravascular sources such as solid tumors.

Adult↗