Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: UMLS:C0027651 (tumor)
685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The matrix metalloproteinase enzymes have been implicated in tumor invasion and metastasis by a series of correlative immunohistochemical studies. In addition, direct evidence for the role of these enzymes in this pathologic process comes from studies using specific metalloproteinase inhibitors to block tumor invasion and metastasis formation, both in vitro and in vivo. Synthetic oligonucleotide primers for four metalloproteinases (MMP-1, MMP-2, MMP-9, MMP-10) and their tissue inhibitors (TIMP-1, TIMP-2) were selected, synthesized, and optimized in the reverse transcriptase-polymerase chain reaction (RT-PCR) to study the qualitative profile of these enzymes and inhibitors in cultured human tumor cells and tumor tissues. These primers are specific and generate unique amplification products for each appropriate enzyme and inhibitor. Slight enhancement in the amplification of cDNA products was achieved by adding dimethylsulfoxide to the reaction mixture, but commercial enhancement reagents were ineffective. Using this RT-PCR method, cDNA amplification was successful with RNA from as few as 20 cultured tumor cells. The RT-PCR analysis was done on three invasive human colon adenocarcinomas and their paired adjacent normal mucosa. The results show MMP-1 and MMP-2 products in all three tumors, and MMP-2 detected in one of the three normal mucosa samples; TIMP-2 expression was present in two of three patients and awaits quantitative assessment of RT-PCR products.
...
PMID:Reverse transcription-polymerase chain reaction phenotyping of metalloproteinases and inhibitors involved in tumor matrix invasion. 826 80

EDTA inhibitable type IV collagenolytic activity copurified with laminin preparations from the Engelbreth-Holm-Swarm (EHS) tumor. Several gelatinolytic and type IV collagenolytic matrix metalloproteinase (MMP) species were visualized in EHS laminin from three different sources by gelatin and type IV collagen substrate gel electrophoresis. Incubation with 4-aminophenylmercuric acetate and trypsin suggested that laminin contained both active and latent MMPs. EHS-derived reconstituted basement membrane, Matrigel, was found to possess an MMP profile identical to that of laminin. The presence of 72-kDa (MMP-2) and 92-kDa (MMP-9) gelatinases/type IV collagenases was demonstrated in laminin and Matrigel preparations by Western blot analysis. A rough quantitation of MMP-2 and MMP-9 in 30 micrograms of laminin and 100 micrograms of Matrigel was between 0.3 and 0.6 ng. The presence of these contaminants must be considered in experiments addressing the effects of EHS laminin or Matrigel on cell behavior and, in particular, stimulation of cellular proteolytic activity.
...
PMID:Identification of the 72-kDa (MMP-2) and 92-kDa (MMP-9) gelatinase/type IV collagenase in preparations of laminin and Matrigel. 829 37

Matrilysin, a member of the matrix metalloproteinase family, is structurally different from the other matrix metalloproteinases by virtue of the absence of a conserved COOH-terminal protein domain. In addition, matrilysin mRNA is regulated in a specific and distinct manner in normal and malignant tissues. Analysis of the genomic structure of the human matrilysin gene revealed that the organization of the first five exons is highly conserved among the different members of the matrix metalloproteinase family, but that matrilysin contains an atypical sixth exon. The promoter region of the matrilysin gene has several features that are conserved among several other matrix metalloproteinase family members, including the presence of TATA, AP-1, and PEA3 elements. Comparison of the expression of the human matrilysin promoter with rat stromelysin promoter/chloramphenicol acetyltransferase constructs in HeLa cells revealed that constructs containing AP-1 and PEA3 elements respond similarly to epidermal growth factor and tumor promoter (12-O-tetradecanoyl-phorbol-13-acetate) induction, but that the addition of upstream stromelysin sequences results in an increased transcriptional activity not observed with upstream matrilysin sequences. The similarities and differences observed between the promoters of matrilysin and the other metalloproteinases may provide insights into the molecular mechanisms that regulate the expression of this family of enzymes as a whole and the factors that distinguish the expression patterns of individual family members.
...
PMID:Structure and expression of the human gene for the matrix metalloproteinase matrilysin. 829 54

The presence and distribution of mRNAs encoding a matrix metalloproteinase (MMP) stromelysin 3 and two tissue inhibitors of MMP, TIMP1 and TIMP-2 have been studied by in situ hybridization of 18 human epidermoid head and neck carcinomas and four normal tissues. We found that in 16 tumors out of 18, stromelysin 3 mRNAs were only expressed by fibroblasts which were in close contact to invasive cancer cells. Tumor cells and normal tissues were not labeled. TIMP-1 mRNAs were detected in well differentiated cancer cells and in endothelial cells in all the cancers. In 13 out of the 18 carcinomas, TIMP-2 mRNAs were localized in only a few stromal cells near well differentiated invasive cancer cells and in endothelial cells. The significant expression of TIMP-1 and TIMP-2 mRNAS may lead to less aggressive MMPs, especially in the case of stromelysin 3, in the invasive process of the stroma.
...
PMID:Localization by in situ hybridization of mRNAs encoding stromelysin 3 and tissue inhibitors of metallo-proteinases TIMP-1 and TIMP-2 in human head and neck carcinomas. 830 24

We have examined the effect of a synthetic low-molecular-weight matrix metalloproteinase inhibitor, [4-(N-hydroxyamino)-2R-isobutyl-3S- (thiopen-2-ylthiomethyl)-succinyl]-L-phenylalanine-N-meth yla mide (BB-94), on human ovarian carcinoma xenografts growing in nude mice. The xenografts grew as thick intraperitoneal mucinous ascites containing free-floating tumor cell clumps. The ascites increased in volume, causing death approximately 3 weeks after introduction. Treatment with BB-94 caused resolution of ascitic disease. Tumor burden was dramatically reduced, and survival increased 5-6-fold. The increase in survival was dose dependent. The effects observed with BB-94 appeared to be due to its matrix metalloproteinase inhibiting effects, inasmuch as its inactive diastereoisomer had no effect on tumor biology. Following treatment with BB-94, free-floating clumps of tumor cells became surrounded by a capsule of host cells. These clumps of tumor cells typically formed one small (approximately 8 mm) avascular tumor of bright white appearance loosely attached to fat in the peritoneum. Tumor cells within these capsules often appeared to be necrotic. Gel substrate analysis demonstrated that activated Mr 92,000 type IV collagenase was present in the xenografts. We propose that inhibition of this enzyme causes the transition of ascites to solid tumors, concomitantly slowing tumor cell growth and allowing the development of tumor stroma.
...
PMID:A synthetic matrix metalloproteinase inhibitor decreases tumor burden and prolongs survival of mice bearing human ovarian carcinoma xenografts. 834 86

Two members of the matrix metalloproteinase family of enzymes, interstitial collagenase and 92-kDa gelatinase, have been implicated in the pathogenesis of rheumatoid arthritis and tumor metastasis. In order to characterize the activities of these enzymes, we have developed a fluorogenic peptide substrate which is efficiently hydrolyzed by both enzymes. This substrate was developed based on the addition of the fluorescent tag, N-methyl-anthranilic acid (Nma), to several previously synthesized substrates that had been evaluated with respect to their turnover by interstitial collagenase. One substrate, Dnp-Pro-Cha-Gly-Cys(Me)-His-Ala-Lys-(Nma)-NH2, had favorable solubility characteristics, was > 98% quenched, and produced a single cleavage product, Dnp-Pro-Cha-Gly, with a high fluorescence yield with both interstitial collagenase and 92-kDa gelatinase. Since the assay depends on measurement of increases in fluorescence, the position of the Nma group also proved to be important for optimization of the fluorescence signal. The assay is free from interference by organomercurial compounds and the cleavage product has excitation and emission spectra compatible with filters commonly available on commercial plate readers. The assay has been adapted to a 96-well format and provides a rapid screening protocol for the evaluation of inhibitors of these enzymes.
...
PMID:A high throughput fluorogenic substrate for interstitial collagenase (MMP-1) and gelatinase (MMP-9). 836 16

The invasion of blood vessel walls is a critical step in cancer metastasis, in which endothelial cells and their vascular basement membranes act as barriers to tumor cell passage. Here we report that Walker 256 carcinosarcoma (W256) cells degrade subendothelial matrices by a process involving both the generation of hydrogen peroxide and the secretion of a matrix metalloproteinase. As an assay of basement membrane degradation, [3H]proline-labeled subendothelial matrices were exposed to W256 cells in the presence or absence of the chemotactic peptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP). The release of [3H]proline, in the presence of 5 x 10(6) W256 cells, was increased from 49 +/- 2.5 to 64 +/- 2.2% by the addition of 10(-6) M fMLP. In the presence of fMLP-activated W256 cells, [3H]proline release was completely inhibited by the addition of 2000 units/ml catalase or by the metalloproteinase inhibitors 1,10-phenanthroline and EDTA at concentrations > or = 10 micrograms/ml. alpha 1-Antitrypsin or alpha 2-macroglobulin were without effect. Cell-free supernatants obtained from activated W256 cells were also able to promote basement membrane degradation. Electrophoresis of the cell-free supernatants from fMLP or PMA-activated W256 cells in gelatin-containing sodium dodecyl sulfate-polyacrylamide gels revealed a major band of gelatinolytic activity at 94 kDa. The 94-kDa band represented the activity of a latent gelatinase since incubation with 1 mM 4-aminophenylmercuric acetate (APMA; a known activator of latent metalloproteinases) resulted in the loss of gelatinolytic activity at 94 kDa and the appearance of five new bands of lower molecular weight (M(r) 86, 79, 74, 70, and 66 kDa). Two of these lower molecular weight bands (M(r) 86 and 66 kDa) were also detected in the absence of APMA, following 10-fold concentration of the cell-free supernatants. When the cell-free supernatants of phorbol myristate acetate-activated W256 cells (concentrated 10-fold) were incubated with increasing concentrations of hydrogen peroxide (35 to 70 mM), the band at 66 kDa demonstrated enhanced gelatinolytic activity. We suggest that W256 cells can secrete a latent metalloproteinase of molecular weight 94 kDa which, when activated by hydrogen peroxide, can degrade subendothelial matrices.
...
PMID:Walker 256 tumor cell degradation of extracellular matrices involves a latent gelatinase activated by reactive oxygen species. 839 53

Human prostate cancer displays a high degree of variability in its rate of spread, which could be due largely to differences in the invasive potential of the tumor cells. The degradation of the basal lamina and stromal extracellular matrix is mediated in part by the secretion of matrix metalloproteinases (MMPs). Matrilysin (PUMP-1, MMP-7) and gelatinase A (M(r) 72,000 type IV collagenase, MMP-2) have been shown to be overexpressed in prostate carcinoma. We have expressed the single MMP matrilysin in the tumorigenic but nonmetastatic human prostate tumor cell line DU-145 to determine if matrilysin has a functional role in prostate tumor cell invasion. DU-145 cells expressing matrilysin were significantly more invasive than vector-only transfected cell lines as assayed by a severe combined immunodeficient mouse model of tumor cell invasion. Vector-only transfected DU-145 cells injected i.p. into severe combined immunodeficient mice invaded the diaphragm in only 1 of 9 mice (11%), whereas matrilysin-transfected DU-145 cells invaded the diaphragm in 12 of 18 mice (66%). The difference between the controls and matrilysin-transfected cells was statistically significant (P < 0.006). These results suggest a functional role for matrilysin in the initial invasion of prostate cancer through the epithelial basal lamina and into the surrounding stroma.
...
PMID:Expression of the metalloproteinase matrilysin in DU-145 cells increases their invasive potential in severe combined immunodeficient mice. 841 33

In vitro analyses of basement membrane invasiveness employing Matrigel (a murine tumor extract rich in basement membrane components) have been performed on human breast cancer model systems. Constitutive invasiveness of different human breast cancer (HBC) cell lines has been examined as well as regulation by steroid hormones, growth factors, and oncogenes. Carcinoma cells exhibiting a mesenchymal-like phenotype (vimentin expression, lack of cell border associated uvomorulin) show dramatically increased motility, invasiveness, and metastatic potential in nude mice. These findings support the hypothesis that epithelial to mesenchymal transition (EMT)-like events may be instrumental in the metastatic progression of human breast cancer. The MCF-7 subline MCF-7ADR appears to have undergone such a transition. The importance of such a transition may be reflected in the emergence of vimentin expression as an indicator of poor prognosis in HBC. Matrix degradation and laminin recognition are highlighted as potential targets for antimetastatic therapy, and analyses of laminin attachment and the matrix metalloproteinase (MMP) family in HBC cell lines are summarized. Matrigel-based assays have proved useful in the study of the molecular mechanisms of basement membrane invasiveness, their regulation in HBC cells, and their potential as targets for antimetastatic therapy.
...
PMID:Molecular and cellular analysis of basement membrane invasion by human breast cancer cells in Matrigel-based in vitro assays. 843 79

The 72 kDa type IV collagenase (gelatinase), a matrix metalloproteinase (MMP-2), has been proposed to potentiate the invasion and metastasis of malignant tumors. To determine the potential role of the MMP-2 in human gliomas and normal brain tissue, we examined the relative amounts of protein, mRNA, and distribution. Using gelatin zymography, densitometry, and an enzyme-linked immunosorbent assay for the quantitative determination of the MMP-2, we found that the enzyme's activity was significantly elevated in malignant astrocytomas, especially in glioblastoma multiforme, compared to low-grade glioma and normal brain tissues. As determined by Northern blot analysis, the amount of MMP-2 mRNA transcript was higher in anaplastic astrocytomas and glioblastoma multiforme tumors than in normal brain tissues or low-grade gliomas, a finding that was consistent with the amounts of MMP-2 protein detected in these tissues. Immunohistochemical studies demonstrated that MMP-2 was localized in tumor cells and vasculature cells of malignant astrocytomas. Staining intensity was clearly lower in low-grade astrocytomas, and immunoreactivity was very low or undetectable in normal brain astrocytes. The results suggest that expression of the MMP-2 is dramatically upregulated in malignant gliomas, correlating with the malignant progression of human gliomas in vivo.
...
PMID:Expression and localization of 72 kDa type IV collagenase (MMP-2) in human malignant gliomas in vivo. 852 15


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---