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

Metalloproteinases (MMPs), a family of enzymes that participate in extracellular matrix degradation and remodeling, may play a role in tumor invasion and metastasis and have been correlated with tumor behavior and survival. The action of MMPs is regulated by tissue inhibitors of MMPs (TIMPs). Adenocarcinomas of the uterine cervix are neoplasms that primarily affect young women and are associated with human papillomavirus (HPV). Eighteen cervical adenocarcinomas and 5 controls were immunohistochemically analyzed for the expression of MMP-2, MMP-3, MMP-9, and their inhibitors, TIMP-1 and TIMP-2, in tumor cells and peritumoral stromal cells. These cells were also studied for the presence of MMP-2, MMP-9, and TIMP-2 mRNA by in situ hybridization (ISH). HPV status was studied using ISH for HPV 16 and 18. MMP-2 and -9 were expressed immunohistochemically in tumor cells in 17 of 18 tumors, MMP-3 in 5, TIMP-1 in 3, and TIMP-2 in 1. Stromal cells of most tumors expressed all the above proteins. The normal endocervical epithelium was uniformly negative for MMP-2, MMP-3, MMP-9, and TIMP-2, and variably expressed TIMP-1. Intense signals for MMP-2, MMP-9, and TIMP-2 mRNA were less frequently detected by ISH in tumor cells and peritumoral stromal cells and were absent in normal endocervical epithelium. All tumors contained HPV DNA 16, 18, or both. MMP and TIMP expression did not correlate with tumor type, grade, or HPV type. MMPs and their inhibitors are present in most cervical adenocarcinomas, independent of tumor grade or subtype, but with the exception of TIMP-1, they are not expressed in nonneoplastic endocervical epithelium. This finding might be helpful in the diagnosis of endocervical adenocarcinomas. HPV is prevalent in cervical adenocarcinomas, but its role in determining tumor behavior remains unclear.
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PMID:Expression of metalloproteinases and their inhibitors in adenocarcinoma of the uterine cervix. 978 29

Matrix metalloproteinase (MMP) activity has been associated with tumor invasion and metastasis in many different tumor types, but recent studies also support a role for these enzymes in earlier stages of the tumor progression continuum. Specifically, the expression pattern of MMPs in benign human and mouse gastrointestinal tumors suggests that they may function in the development or growth of non-invasive tumors. To address the contribution of MMP activity to the development of intestinal adenomas, we administered the synthetic MMP inhibitor batimastat and expressed the tissue inhibitor of metalloproteinases-1 (TIMP-1) in the gastrointestinal tract of Min mice, which spontaneously develop pre-malignant small and large intestinal tumors. Batimastat administration resulted in a 48% decrease in the number of Min tumors. This reduction in tumor number is similar to that observed in mice lacking the metalloproteinase matrilysin, and demonstrates the therapeutic and chemopreventive potential of MMP inhibitors for pre-malignant intestinal tumors. In contrast, forced TIMP-1 expression in transgenic mice had no effect or, in one line, unexpectedly augmented Min tumor multiplicity by 32%. This observation supports an in vivo tumor-promoting activity of TIMP-1 that could be related to the growth stimulatory effects of TIMP that have been documented in vitro. Taken together, these 2 approaches of modulating MMP activity in Min mice support a critical function of MMPs in Min tumorigenesis, underscore the importance of an MMP/inhibitor balance in maintaining tissue homeostasis and demonstrate that endogenous MMP inhibitors can have complex effects in particular cellular contexts.
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PMID:Differing effects of endogenous and synthetic inhibitors of metalloproteinases on intestinal tumorigenesis. 980 34

Tumor cell invasion and metastasis requires precise coordination of adherence to the extracellular matrix (ECM) and controlled degradation of its components. lnvasive cells secrete proteolytic enzymes known as matrix metalloproteinases which degrade specific basement membrane molecules. Expression of these enzymes is regulated by multiple signaling mechanisms, including attachment to the extracellular matrix via integrins. All-trans retinoic acid can inhibit tumor cell invasion of ECM by regulating matrix metalloproteinase expression. Using a series of squamous cell carcinoma lines, we investigated the interactions between integrin and retinoic acid signaling in these cells. In a cell line sensitive to RA-mediated inhibition of invasion, this ligand downregulated MMP-9 activity in cells grown on specific ECM molecules but not on plastic. Inhibition of integrin signaling with anti-alpha1 antibodies or MAPK pathway inhibitors abrogated RA mediated down-regulation of MMP-9 activity and invasion. The effects of RA and MAPK signaling on MMP-9 activity was mediated at the transcriptional level. These data indicate that crosstalk between RA- and integrin dependent signaling pathways regulate MMP activity and invasion in squamous cell carcinoma lines.
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PMID:alpha2beta1 integrin signaling via the mitogen activated protein kinase pathway modulates retinoic acid-dependent tumor cell invasion and transcriptional downregulation of matrix metalloproteinase 9 activity. 982 20

Overexpression of the epithelial specific matrix metalloproteinase matrilysin (MAT) has been correlated with enhanced tumorigenicity and tumor cell invasion using in vitro model systems. We have determined the effects of MAT expression on the development of mammary tumorigenesis using transgenic mice that express human MAT under the control of the mouse mammary tumor virus (MMTV)-long terminal repeat promoter/enhancer. Examination of mammary glands from multiparous MMTV-MAT animals revealed the development of premalignant hyperplastic alveolar nodules in 50% of aged females. MMTV-MAT mice were mated with MMTV-neu transgenic mice to determine the effect of MAT on neu-induced mammary tumorigenesis. Bigenic MMTV-MAT/neu female offspring developed primary mammary tumors approximately 13 weeks earlier than did MMTV-neu controls. The mechanism of enhanced neu-induced tumorigenesis was explored. No discernible difference in Neu receptor dimerization or activation was detected in MMTV-MAT/neu tumors or mammary glands compared to MMTV-neu controls. A similar percentage of MMTV-MAT/neu and MMTV-neu tumors acquired deletions in the neu transgene, which have previously been shown to result in constitutive receptor activation. The presence of premalignant nodules and the accelerated development of oncogene-induced mammary tumors suggest that expression of MAT in the mammary epithelium contributes to early-stage mammary tumorigenesis.
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PMID:The matrix metalloproteinase matrilysin influences early-stage mammary tumorigenesis. 985 86

Activation of the matrix metalloproteinase 2 (MMP-2) has been shown to play a major role in the proteolysis of extracellular matrix (ECM) associated with tumor invasion. Although the precise mechanism of this activation remains elusive, levels of the membrane type 1-MMP (MT1-MMP) at the cell surface and of the tissue inhibitor of MMP-2 (TIMP-2) appear to be two important determinants. Induction of MMP-2 activation in cells cultivated on collagen type I gels indicated that the ECM is important in the regulation of this process. In this study, we show that SPARC/osteonectin, a small ECM-associated matricellular glycoprotein, can induce MMP-2 activation in two invasive breast cancer cell lines (MDA-MB-231 and BT549) but not in a noninvasive counterpart (MCF-7), which lacks MT1-MMP. Using a set of peptides from different regions of SPARC, we found that peptide 1.1 (corresponding to the NH2-terminal region of the protein) contained the activity that induced MMP-2 activation. Despite the requirement for MT1-MMP, seen in MCF-7 cells transfected with MT1-MMP, the activation of MMP-2 by SPARC peptide 1.1 was not associated with increased steady-state levels of MT1-MMP mRNA or protein in either MT1-MMP-transfected MCF-7 cells or constitutively expressing MDA-MB-231 and BT549 cells. We did, however, detect decreased levels of TIMP-2 protein in the media of cells incubated with peptide 1.1 or recombinant SPARC; thus, the induction of MMP-2 activation by SPARC might be due in part to a diminution of TIMP-2 protein. We conclude that SPARC, and specifically its NH2-terminal domain, regulates the activation of MMP-2 at the cell surface and is therefore likely to contribute to the proteolytic pathways associated with tumor invasion.
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PMID:SPARC/osteonectin induces matrix metalloproteinase 2 activation in human breast cancer cell lines. 985 90

Angiostatin, a cleavage product of plasminogen, has been shown to inhibit endothelial cell proliferation and metastatic tumor cell growth. Recently, the production of angiostatin has been correlated with tumor-associated macrophage production of elastolytic metalloproteinases in a murine model of Lewis lung cell carcinoma. In this report we demonstrate that purified murine and human matrix metalloproteinases generate biologically functional angiostatin from plasminogen. Macrophage elastase (MMP-12 or MME) proved to be the most efficient angiostatin-producing MMP. MME was followed by gelatinases and then the stomelysins in catalytic efficiency; interstitial collagenases had little capacity to generate angiostatin. Both recombinant angiostatin and angiostatin generated from recombinant MME-treated plasminogen inhibited human microvascular endothelial cell proliferation and differentiation in vitro. Finally, employing macrophages isolated from MME-deficient mice and their wild-type littermates, we demonstrate that MME is required for the generation of angiostatin that inhibits the proliferation of human microvascular endothelial cells.
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PMID:Matrix metalloproteinases generate angiostatin: effects on neovascularization. 986 16

EMMPRIN (extracellular matrix metalloproteinase inducer) stimulates fibroblast metalloproteinases (MMP) 1, 2 and 3 (Kataoka et al. (1993) Cancer Res. 53, 3154-3158). Here we focus on MMP-1, showing that in lung tumors, MMP-1's cognate mRNA is strongly expressed in stromal fibroblasts adjacent to EMMPRIN-expressing tumor cells. In vitro, EMMPRIN upregulates MMP-1 mRNA expression in a concentration-dependent manner, with a peak accumulation at 24 h. The response is genistein-sensitive, suggesting it is dependent on tyrosine kinase activity. Analysis of tyrosine phosphorylation-dependent MAP kinases ERK 1/2, SAPK/JNK, and p38 showed that the activity of p38 but not that of the other 2 kinases was elevated in response to EMMPRIN. That p38 activity was required for EMMPRIN stimulation of MMP-1 was evident from results showing that the p38 inhibitor SB203580 blocked this response. This is the first available information regarding the mechanism by which tumor-associated molecules upregulate MMP synthesis in stromal fibroblasts.
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PMID:Tumor-derived EMMPRIN (extracellular matrix metalloproteinase inducer) stimulates collagenase transcription through MAPK p38. 987 71

Tumor cells at the stage of tumor progression build up a high tolerance to intrinsic and extrinsic defence systems and/or therapeutic procedures, and the cells deeply infiltrate the adjacent tissue, which is followed by tumor metastasis to remote organs and tissues. This study was designed to investigate the relationship between expression of matrix metalloproteinase-2 (MMP-2) and invasiveness of human bladder cancer cells, using cell lines derived from a parental human urinary bladder tumor cell line, T24. Two subpopulations of the human bladder cancer cell line T24, Hi-T24 and Lo-T24, were selected using an invasion assay and then expression of MMP-2 mRNA and protein was analyzed by reverse-transcription polymerase chain reaction (RT-PCR) and enzyme immunoassay (EIA). The gross morphology, cell growth rate, and adhesion activity to a basement membrane extract (matrigel) of the high-invasive Hi-T24 cells were similar to those of the low-invasive Lo-T24 cells, but the Hi-T24 cells were 3.8-fold more haptotactic through matrigel than the Lo-T24 cells. The haptotactic activity of the Hi-T24 cells was suppressed by the addition of an anti-MMP-2 antibody, and the amounts of MMP-2 protein secreted into the spent medium by the Hi-T24 and Lo-T24 cells were 7.8+/-0.2 and 3.8+/-0.3 ng/ml (P<0.05), respectively. The quantities of tissue inhibitor of metalloproteinase-2 (TIMP-2) protein secreted by Hi-T24 and Lo-T24 cells were 133.2+/-4.3 and 168.7+/-5.6 ng/ml, respectively (P<0.05). The levels of transcription of the genes encoding MMP-2 and the transmembrane MMP, MT-MMP, evaluated by RT-PCR, were higher in the Hi-T24 cells than in the Lo-T24 cells. Expression of the TIMP-2 gene was slightly lower in the Hi-T24 cells than in the Lo-T24 cells. These results indicate that expression of the metalloproteinases are imbalanced at the gene level in human urinary bladder cancer cells at the stage of tumor progression.
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PMID:Tumor progression and expression of matrix metalloproteinase-2 (MMP-2) mRNA by human urinary bladder cancer cells. 987 15

Tumor invasion into the extracellular matrix (ECM) and basement membrane (BM) is a crucial step of tumor metastasis. In order to investigate the possible therapeutic procedure for the tumor invasion, we investigated the anti-invasive activities of several synthetic serine protease inhibitors. FOY-305, a serine protease inhibitor, showed no cytotoxic activity against human HT-1080 fibrosarcoma cells at concentrations ranging from 0.1 to 100 micrograms/ml, while its analogs ONO-3403 and FO-349 showed slight cytotoxic activities at the concentration of 100 micrograms/ml. These compounds inhibited the activity of urokinase-type plasminogen activator (u-PA) which is one of serine proteases and considered to be associated with tumor invasion and metastasis in fibrin zymography. FOY-305 more potently inhibited the invasion of HT-1080 cells into the reconstituted BM Matrigel, as well inhibited u-PA activity, compared with ONO-3403 and FO-349. These results suggest that the anti-invasive activity of these compounds is consistent with their anti-fibrinolytic activities. In addition, the combined treatment of FOY-305 with FC-336 processing anti-invasive and anti-MMP properties resulted in marked enhancement of anti-invasive activity. In conclusion, FOY-305 inhibited the invasion of tumor cells through interference with the u-PA activity of tumor cells, and this inhibitory activity was augmented by the combination with a MMP inhibitor.
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PMID:Anti-invasive activity of synthetic serine protease inhibitors and its combined effect with a matrix metalloproteinase inhibitor. 989 76

Matrix metalloproteinases have been implicated to play a vital role in glioma invasion as they degrade extracellular matrix to facilitate the subsequent migration of tumor cells into the surrounding brain tissue. The cytokine Interleukin-10 (IL-10) was detected recently in glial tumors in vivo. Expression of specific IL-10 mRNA as well as blood serum levels of IL-10 in glioma patients increased with malignancy suggesting a functional role of IL-10 in glioma progression. Moreover, glioma cell migration in vitro was enhanced in the presence of IL-10. We therefore investigated the expression of the matrix metalloproteinases (MMPs) stromelysin-1 (MMP-3), 72-kDa collagenase (MMP-2), 92-kDa collagenase (MMP-9), matrilysin (MMP-7) and the human macrophage metalloelastase (MMP-12). In addition, a possible relation between exposure of glioma cells to IL-10 and invasiveness of these cells due to MMP expression was analyzed. Experiments with Matrigel coated Boyden chambers revealed a pronounced dose dependent effect of IL-10 on glioma invasiveness. The synthetic MMP-inhibitor Marimastat markedly reduced cell invasion in the Boyden chambers confirming the significance of MMPs in the process of invasion. Subsequently, the expression level of MMPs and the serine protease uPA was investigated in 7 glioma cell lines (U373, GaMG, U251, GHE, SNB19, U138 and D54) by RT-PCR. In all but one cell line no enhancement of MMP expression by IL-10 was detected. Matrilysin in U373 cells was the only protease found to be upregulated in the presence of IL-10 dependent on cell density. The present data suggest that IL-10 related effects on the invasive properties of the cell lines are not directly mediated by an upregulation of matrix metalloproteinase expression.
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PMID:Expression of matrix metalloproteinases in human glioma cell lines in the presence of IL-10. 989 93


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