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

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Query: EC:3.4.24.3 (collagenase)
18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The stroma reaction plays a central role in tumor growth, invasion and metastasis. Tumor growth is dependent on angiogenesis and requires the vascular supply provided by new capillary blood vessels of the stroma. The expression of the gene encoding the transcription factor c-ets1 is localized within fibroblasts and endothelial cells of the stromal compartment. This expression correlates with the accumulation of transcripts for potential target genes such as collagenase I and stromelysin I in stromal fibroblasts surrounding malignant cells in invasive tumors. We suggest that c-Ets1 protein might regulate the transcription of the genes coding for matrix-degrading proteases necessary for both angiogenesis and tumor invasion.
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PMID:Invasive tumors induce c-ets1 transcription factor expression in adjacent stroma. 857 98

Four potent, synthetic inhibitors of matrix metalloproteinases (MMPs) were assessed as inhibitors of tumor growth and spontaneous metastasis to the lung. Mat Ly Lu rat prostate tumor, LOX human melanoma and M27 murine Lewis lung tumor were implanted subcutaneously (s.c.) in mice and allowed to grow for 3-12 days. The lungs of the tumor-bearing mice were then removed and implanted s.c. into untreated mice, and the outgrowth of secondary tumors from the implanted lungs measured. The incidence and rate of outgrowth of secondary tumors increased with the length of primary tumor growth, validating these measurements as indices of spontaneous metastasis to the lung. Compounds were tested by s.c. implantation of minipumps which delivered compound throughout the period of primary tumor growth and spontaneous metastasis to the lung at steady-state drug concentrations orders of magnitude greater than the concentrations needed to either inhibit collagenase, gelatinase or stromelysin in vitro. Inhibitor treatment slowed the growth of primary s.c. Mat Ly Lu and LOX tumors by 40-60% but had no significant effect on the growth of primary M27 tumors. Surprisingly, inhibitor treatment had no significant effect on the ability of the lung to generate secondary tumors when reimplanted s.c. in untreated mice. Because of the possible importance of cathepsins B, H and L in tumor growth and metastasis, the irreversible inhibitor E-64 was also infused by s.c. minipump. E-64 had no effect on the growth or spontaneous metastasis of Mat Ly Lu or M27 tumors.
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PMID:Effect of matrix metalloproteinase inhibitors on tumor growth and spontaneous metastasis. 860 25

Does the c-ets 1 protooncogene take part in the regulation of tumor angiogenesis? The formation of new blood vessels is an essential process in embryonic development and wound healing, for tumor growth and metastasis. In situ hybridization studies have revealed that the protooncogene c-ets 1 is expressed in endothelial cells at the beginning of blood vessel formation, in normal and pathological conditions. C-ets 1 encodes a transcription factor, a protein which binds specifically to DNA and which regulates the transcription of genes containing these specific binding sequences in their promotors. Thus in vitro experiments suggest that c-ets 1 may activate the transcription of genes encoding collagenase 1, stromelysine 1 and urokinase plasminogen activator, proteases involved in extracellular matrix degradation. A working hypothesis is that c-ets 1 takes part in regulating angiogenesis by controlling the transcription of these genes whose activity is necessary for the migration of endothelial cells from preexisting capillaries. This hypothesis is discussed with respect to current experimental evidences and to the complexity of the regulatory network controlling gene transcription and extracellular matrix degradation.
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PMID:[Does the c-ets 1 oncogene participate in the regulation of tumor angiogenesis?]. 880 51

Expression of interleukin-8 (IL-8) by human melanoma cells correlates with their metastatic potential. Moreover, UV-B irradiation of primary cutaneous melanoma cells induces IL-8 mRNA and protein production and increases both tumor growth and metastasis in nude mice. Although IL-8 has been shown to be an angiogenic factor, the biological consequences of increased IL-8 production by melanoma cells and the role of IL-8 in the metastatic process remains unclear. The purpose of this study was to determine the role of IL-8 in tumor growth and metastasis of human melanoma cells. Nonmetastatic SB-2 melanoma cells with negligible levels of IL-8 were transfected with IL-8 cDNA and subsequently analyzed for changes in their tumorigenic and metastatic potential. Enforced expression of IL-8 rendered the melanoma cells highly tumorigenic and increased their metastatic potential as compared with parental and control transfected cells. The IL-8-transfected cells displayed up-regulation in M(r) 72,000 collagenase type IV (MMP-2) mRNA and collagenase activity and increased invasiveness through Matrigel-coated filters. Moreover, when the MMP-2 promoter was linked upstream of the chloramphenicol acetyltransferase (CAT) reporter gene, CAT activity was up-regulated in IL-8 but not in control transfected cells, suggesting that IL-8 is involved in MMP-2 gene transcription. Activation of type IV collagenase by IL-8 can enhance the invasion of host stroma by the tumor cells and increase angiogenesis and, hence, metastasis.
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PMID:Expression of interleukin-8 by human melanoma cells up-regulates MMP-2 activity and increases tumor growth and metastasis. 932 44

Although a number of effective therapies are available for localized prostate cancer, metastatic prostate cancer is difficult to treat and impossible to cure. Identification of the gene products that enable a prostatic carcinoma cell to metastasize should facilitate an understanding of the processes leading to metastasis. To characterize the contribution of matrix metalloproteinase-9 (MMP-9, gelatinase B or the 92-kd type IV gelatinase/collagenase) to the development of metastasis in prostate cancer, we reduced MMP-9 expression in metastatic murine prostatic carcinoma cells using a ribozyme. The ribozyme transfected cells had lower basal levels of MMP-9 as well as decreased levels after stimulation by transforming growth factor-beta or phorbol 12-myristate 13-acetate when compared with the parental cells or with control transfectants. The cells with down-regulated MMP-9 were unable to form lung colonies in the experimental metastasis assay, whereas the controls and parental cells readily formed metastases. All cell types readily formed tumors after injection and down-regulation of MMP-9 did not adversely affect the rate of tumor growth. Thus, MMP-9 expression is required for hematogenous metastasis in a murine prostate model system raising the possibility that it may play an equivalent role in human prostate cancer.
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PMID:Requirement for matrix metalloproteinase-9 (gelatinase B) expression in metastasis by murine prostate carcinoma. 946 86

Dietary genistein, a natural flavone compound found in soy, has been proposed to be responsible for the low rate of breast cancer in Asian women. The cellular mechanisms of genistein's chemopreventive effects in vio have been largely unexplored. In our previous studies, we found that genistein exerted pronounced antiproliferative effects on both estrogen receptor-positive and -negative human breast carcinoma cells through G2-M arrest, induction of p21WAF1/CIP1 expression, and apoptosis. Because chemopreventive effects need not be limited to antiproliferation, we decided to examine whether genistein exerted other suppressive effects on breast carcinoma progression. Genistein inhibited invasion in vitro of MCF-7 and MDA-MB-231 cells. This inhibition was characterized by down-regulation of MMP (matrix metalloproteinase)-9 and up-regulation of tissue inhibitor of metalloproteinase-1, the former of which was transcriptionally regulated at activation protein-1 sites in the MMP-9 promoter. Genistein's in vitro effects on MMP-9 and tissue inhibitor of metalloproteinase-1 were also demonstrated in in vivo studies in nude mouse xenografts of MDA-MB-231 and MCF-7 cells. In these xenograft studies, genistein inhibited tumor growth, stimulated apoptosis, and upregulated p21WAF1/CIP1 expression. In the MDA-MB-231 xenograft, genistein also inhibited angiogenesis by decreasing vessel density and decreasing the levels of vascular endothelial growth factor and transforming growth factor-beta1. These in vitro and in vivo studies demonstrate that genistein exerts multiple suppressive effects on breast carcinoma cells, suggesting that its mechanism of chemoprevention is pleiotropic.
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PMID:Genistein exerts multiple suppressive effects on human breast carcinoma cells. 980 90

One of the primary antioxidant enzymes, manganese-containing superoxide dismutase (MnSOD), has shown the ability to reverse malignant phenotypes in a variety of human tumor cells that are low or absent in MnSOD expression. We have observed that overexpression of human MnSOD in human breast cancer MCF-7 cells inhibits tumor growth both in vitro and in vivo. The signaling pathway underlying the MnSOD induced tumor suppression is unknown. We demonstrate here that transcriptional and DNA binding ability of AP-1 and NF-kappaB, but not SP-1, were inhibited (by 50%) in the MCF-7 cell line overexpressing MnSOD. When transiently expressing, MnSOD inhibited AP-1 but increased NF-kappaB transactivation, which can be abolished by sodium pyruvate, a hydrogen peroxide scavenger. To analyze the target genes responsible for MnSOD-induced tumor suppression, genes related to tumor growth and responsive to AP-1 or NF-kappaB were analyzed. AP-1 responsive collagenase I, stromelysin I, and NF-kappaB responsive IL-1 and IL-6 were down-regulated in the MnSOD stable transfectants compared to the control cell lines. Since TPA induces differentiation in human breast cancer cells and up-regulates MnSOD gene in HeLa cells, MnSOD expression and AP-1 and NF-kappaB activity were measured under TPA treatment. The results showed that TPA induced endogenous MnSOD expression and inhibited both AP-1 and NF-kappaB. Together, these results suggest that tumor suppression by overexpressing MnSOD is related to a modulation of AP-1 and NF-kappaB, which causes a down-regulation of genes responsible for tumor malignant phenotype.
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PMID:Inhibition of AP-1 and NF-kappaB by manganese-containing superoxide dismutase in human breast cancer cells. 983 61

Matrix metalloproteinases (MMPs) are believed to contribute to the complex process of cancer progression. They also exhibit an alpha1-proteinase inhibitor (alphaPI)-degrading activity generating a carboxyl-terminal fragment of approximately 5 kd (alphaPI-C). This study reports that overexpression of alphaPI-C in S2-020, a cloned subline derived from the human pancreas adenocarcinoma cell line SUIT-2, potentiates the growth capability of the cells in nude mice. After stable transfection of a vector containing a chimeric cDNA encoding a signal peptide sequence of tissue inhibitor of metalloproteinase-1 followed by cDNA for alphaPI-C into S2-020 cells, three clones that stably secrete alphaPI-C were obtained. The ectopic expression of alphaPI-C did not alter in vitro cellular growth. However, subcutaneous injection of the alphaPI-C-secreting clones resulted in tumors that were 1.5 to 3-fold larger than those of control clones with an increased tendency to invasiveness and lymph node metastasis. These effects could be a result of modulation of natural killer (NK) cell-mediated control of tumor growth in nude mice, as the growth advantage of alphaPI-C-secreting clones was not observed in NK-depleted mice, and alphaPI-C-secreting clones showed decreased NK sensitivity in vitro. In addition, production of alphaPI and generation of the cleaved form of alphaPI by MMP were observed in various human tumor cell lines and in a highly metastatic subline of SUIT-2 in vitro. These results provide experimental evidence that the alphaPI-degrading activity of MMPs may play a role in tumor progression not only via the inactivation of alphaPI but also via the generation of alphaPI-C.
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PMID:Enhanced tumor growth and invasiveness in vivo by a carboxyl-terminal fragment of alpha1-proteinase inhibitor generated by matrix metalloproteinases: a possible modulatory role in natural killer cytotoxicity. 1002 4

Experimental evidence has directly implicated matrix metalloproteinases (MMPs) in the remodeling of the stromal tissue surrounding tumors. Thus, MMP inhibitors could limit the expansion of both neoplastic cell compartment and endothelial cell compartment of a tumor. Much of the work on the role of MMP inhibitors has concentrated on their inhibitory effects on tumor cell invasion. We have examined the effects of a new MMP inhibitor, KB-R7785 (acting on MMP-1, MMP-3, and MMP-9), on tumor angiogenesis and metastasis of murine colon adenocarcinoma (C-26) in two tumor models in BALB/c mice (transparent chamber model and lung colonization model). KB-R7785 has not shown inhibitory effects on in vitro growth of either C-26 or KOP2.16 murine endothelial cells. In vivo, KB-R7785 administrated twice daily for 15 days (100 mg/kg, i.p.), starting the day of tumor inoculation (5 x 10(5) C26 cells) in transparent chamber, has resulted in 88.2% suppression of tumor growth, compared with that in vehicle-administered mice (controls). Tumors grown in controls have doubled their area in 3.3 days, whereas those treated by KB-R7785 progressed almost four times slower (tumor area doubling time, 12 days). KB-R7785 rendered centrally avascular tumors with only a rim of peripheral neovasculature, which had significant lower functional vascular density and vascular area than the corresponding parameters in control tumors 10 days after inoculation [79.9+/-6.7 cm/cm2 versus 164.1+/-10.1 cm/cm2 (P < 0.01) and 19.8+/-1.5% versus 42.6+/-2.7% (P < 0.01), respectively]. In the lung colonization model (tail vein inoculation of 5 x 10(5) C-26 cells), administration of KB-R7785 (100 mg/kg, i.p.) twice daily for 20 days has reduced the number of surface metastasis by 85.8% and abolished the tumor burden, as compared with controls. The few metastatic colonies found in the lungs of KB-R7785 treated mice appeared to be dormant (i.e., staining with von Willebrand factor antibody revealed few, if any, positive cells within the metastatic foci from MMP inhibitor-treated lungs, whereas terminal deoxynucleotidyl transferase-mediated nick end labeling showed a 4-fold increase in the rate of tumor cell apoptosis compared with controls. The fact that KB-R7785 interferes with early steps of angiogenesis and cancer spread suggests that MMP inhibitors may control both primary and secondary tumor growths by limiting the expansion of endothelial cells, as well as cancer cells, composing the tumors.
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PMID:Controlling tumor angiogenesis and metastasis of C26 murine colon adenocarcinoma by a new matrix metalloproteinase inhibitor, KB-R7785, in two tumor models. 1009 56

We have devised a new drug screening assay to discover anti-cancer drugs which inhibit Ras-mediated cellular signals, by utilizing a Ras-responsive element (RRE)-driven reporter gene system. We found that hypothemycin, an anti-bacterial, reduces RRE-dependent transcription. Treatment of tumor cells with hypothemycin resulted in reduced expression of Ras-inducible genes, including MMP (matrix metalloproteinase)-1, MMP-9, transforming growth factor-beta (TGF-beta), and vascular endothelial growth factor (VEGF), but not that of the constitutively expressed gene, MMP-2. The results of zymography demonstrated that hypothemycin reduced the production of MMP-9 and MMP-3, another Ras-inducible MMP, in the culture medium. Hypothemycin selectively inhibits anchorage-independent growth of Ras-transformed cells in comparison with anchorage-dependent growth. These findings suggest that hypothemycin inhibits Ras-mediated cellular signaling. Daily treatment of tumor-bearing mice with hypothemycin resulted in significant inhibition of tumor growth. Since MMP-1, MMP-3 and MMP-9 play important roles in tumor invasion and TGF-beta and VEGF are involved in tumor angiogenesis, hypothemycin is considered to be an example of a new class of antitumor drugs, whose antitumor efficacy can be at least partly attributed to inhibition of Ras-inducible genes.
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PMID:Antitumor efficacy of hypothemycin, a new Ras-signaling inhibitor. 1059 43


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