Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gelatin zymography is the common method for examining matrix metalloproteinase-2 (MMP-2) in cells and media samples. Activation of the latent MMP-2 zymogen involves its binding to the cell surface MT1-MMP*TIMP-2 (membrane type-1 matrix metalloproteinase/tissue inhibitor of matrix metalloproteinase-2) complex with subsequent cleavage of proMMP-2 by TIMP-2-free adjacent MT1-MMP. This is followed by autolytic maturation of the activation intermediate and the release of the mature MMP-2 species from cell surfaces into the extracellular milieu. To observe the MMP-2 activation pathway in more detail, proMMP-2-deficient MCF7 breast carcinoma cells expressing MT1-MMP were incubated with excess proMMP-2 to saturate the available MT1-MMP*TIMP-2 surface receptors. After removal of the unbound material, the kinetics of proMMP-2 activation and MMP-2 release from cells into media was monitored by gelatin zymography and substrate cleavage. Our observations demonstrate that gelatin zymography is insufficient for providing meaningful information about the status of MMP-2. The proteolytically competent mature MMP-2 moiety alone, but not in its complex with TIMP-2, was released from the cells. In tissue culture conditions, the enzyme's proteolytic activity was suppressed in the next 30 to 60 minutes by tissue inhibitors of MMPs, especially by TIMP-1. The picture emerges that there is a likely temporal regulation of MMP-2 activity by TIMPs in tumor cells. These relatively rapid changes of the MMP-2 status cannot be detected by gelatin zymography. Additional studies are needed to examine the significance of this phenomenon in vivo.
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PMID:Gelatin zymography and substrate cleavage assays of matrix metalloproteinase-2 in breast carcinoma cells overexpressing membrane type-1 matrix metalloproteinase. 1242 18

Various extracts prepared from stems of Euonymus alatus were tested for cytotoxic activity on human hepatocellular carcinoma cell line, Hep3B cells using the XTT assay method. Also, the extracts were investigated the inhibitory effects on matrix metalloproteinase (MMP)-9 activity using gelatin zymography. The methanol extract, hexane and ethyl acetate fraction exhibited weak cytotoxic activity (IC(50) of >100 microg/ml). However, butanol (IC(50)=65 microg/ml) and chloroform (IC(50)=85 microg/ml) fraction exhibited strongly cytotoxic activity. Gelatin zymography showed that the Hep3B cells secreted matrix metalloproteinase (MMP), probably including MMP-9, which may be involved in tumor cell invasion and metastasis. The butanol fraction showed stronger inhibitory effect of proteolytic activity than other fractions. Also, the butanol fraction was able to decrease the proteolytic activity of MMP-9 in a concentration-dependent manner on zymography. These results suggest that the butanol fraction from E. alatus has highly inhibitory effect on MMP-9 in comparatively low cytotoxicity.
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PMID:Inhibitory effect of methanol extract of Euonymus alatus on matrix metalloproteinase-9. 1257 16

Photodynamic therapy (PDT) clinical results are promising; however, tumor recurrences can occur and, therefore, methods for improving treatment efficacy are needed. PDT elicits direct tumor cell death and microvascular injury as well as expression of angiogenic, inflammatory, and prosurvival molecules. Preclinical studies combining antiangiogenic drugs or cyclooxygenase-2 inhibitors with PDT show improved treatment responsiveness (A. Ferrario et al., Cancer Res 2000;60:4066-9; A. Ferrario et al., Cancer Res 2002;62:3956-61). In the present study, we evaluated the role of Photofrin-mediated PDT in eliciting expression of matrix metalloproteinases (MMPs) and modulators of MMP activity. We also examined the efficacy of a synthetic MMP inhibitor, Prinomastat, to enhance tumoricidal activity after PDT, using a mouse mammary tumor model. Immunoblot analysis of extracts from PDT-treated tumors demonstrated strong expression of MMPs and extracellular MMP inducer along with a concomitant decrease in expression of tissue inhibitor of metalloproteinase-1. Gelatin zymography and enzyme activity assays performed on protein extracts from treated tumors confirmed the induction of both latent and enzymatically active forms of MMP-9. Immunohistochemical analysis indicated that infiltrating inflammatory cells and endothelial cells were primary sources of MMP-9 expression after PDT, whereas negligible expression was observed in tumor cells. Administration of Prinomastat significantly improved PDT-mediated tumor response (P = 0.02) without affecting normal skin photosensitization. Our results indicate that PDT induces MMPs and that the adjunctive use of an MMP inhibitor can improve PDT tumor responsiveness.
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PMID:The matrix metalloproteinase inhibitor prinomastat enhances photodynamic therapy responsiveness in a mouse tumor model. 1505 80

We investigated the ability of angiogenesis in PC9/F9 cells (from a highly metastatic human lung adenocarcinoma cell line) as compared with PC9 cells (from a low metastatic human lung adenocarcinoma cell line). In vivo tumor growth assay using BALB/c nude mice (7 mice/group), showed that the tumor volume of PC9/F9 cells on day 35 (230.7+/-31.3 mm(3)) was significantly larger than that of PC9 cells (90.9+/-24.7 mm(3)) (p<0.001). However, there was no significant difference between PC9/F9 cells and PC9 cells in an in vitro growth assay. In a dorsal air sac assay (DAS assay) using ICR mice (3 mice/group), PC9/F9 cells (4.7+/-1.2 vessels) showed stronger neovascurizationin in compared with PC9 cells (0.3+/-0.4 vessels) (p<0.05). In an enzyme linked immunosorbent assay (ELISA) and Western blotting analysis there were no significant differences between PC9/F9 cells and PC9 cells in the protein expression of vascular endothelial growth factor (VEGF). There was no significant difference between the gene expression levels of PC9/F9 cells and PC9 cells on cDNA array analysis. Matrix metalloproteinase-2 (MMP-2) activity in PC9/F9 cells was remarkably stronger than that of PC9 cells in Gelatin Zymography. From these results, we considered that of the increased metastasis of PC9/F9 cells might be induced by augmented angiogenesis. Furthermore, we speculated that the augmented angiogenesis of the highly metastatic PC9/F9 cell line might be induced by increased MMP-2 activity.
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PMID:The difference of angiogenesis in human lung adenocarcinoma cell lines with different metastatic potency. 1522 9

We investigated the interaction between tumor cells and stromal fibroblasts in tumor invasion of oral squamous cell carcinoma. Gelatin zymography showed that high levels of matrix metalloproteinase (MMP)-9 were present in the tissue of squamous cell carcinoma. When tumor cells and fibroblasts were isolated from the tissue and cultured separately, significant levels of MMP-9 were lost in the culture media of tumor cells as well as fibroblasts. When tumor cells and fibroblasts were cocultured in the presence of tumor necrosis factor alpha, high levels of MMP-9 were recovered in the culture media. The levels of MMP-9, which were secreted from tumor cells, but not fibroblasts, correlated with the number of cocultured fibroblasts. Cocultured fibroblasts, moreover, enhanced the induction of an active form of MMP-9, cell motility, and the activation of a transcription factor NF-kappaB in tumor cells. Stromal fibroblasts may induce NF-kappaB activation and promote the invasion of oral squamous cell carcinoma.
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PMID:NF-kappaB involvement in tumor-stroma interaction of squamous cell carcinoma. 1550 97

The aim of this study was to explore the potential role of AKT2 in glioma cell invasion. Therefore, dominant-negative (DN-AKT2) and antisense AKT2 constructs (AS-AKT2) were transfected into rat C6 glioma cells with elevated endogenous AKT2 expression. In situ hybridization and Western blot analysis were used to identify AKT2 expression. Spheroid culturing was used to assess cell migration and invasion in Matrigel from spheroids. Cell motility and invasion were also evaluated by scratch and Transwell invasion assays, respectively. The secretion of matrix metalloproteinases (MMPs), MMP2 and MMP9, was determined by gelatin zymography. AKT2 expression was inhibited in C6 cells transfected with AS-AKT2 but did not significantly change in cells transfected with DN-AKT2. The cell migration distance from spheroids or the number of cells migrating into the acellular space created by scratching was reduced in cells transfected with DN-AKT2 or AS-AKT2 compared to the control cells. The invasive distance of cells from the spheroids in Matrigel sandwich and the number of invading cells through the Matrigel were also decreased in the DN-AKT2- and AS-AKT2-transfected cells. Gelatin zymography showed that the production of MMP2 and MMP9 was inhibited in transfected cells. In conclusion, AKT2 plays an important role in glioma cell motility and invasion. Therapy based on AKT inhibition may complement currently available treatment to control glioma cell invasion.
Tumour Biol
PMID:Antisense and dominant-negative AKT2 cDNA inhibits glioma cell invasion. 1555 54

Rapamycin has previously been shown to be efficacious against intracerebral glioma xenografts and to act in a cytostatic manner against gliomas. However, very little is known about the mechanism of action of rapamycin. The purpose of our study was to further investigate the in vitro and in vivo mechanisms of action of rapamycin, to elucidate molecular end points that may be applicable for investigation in a clinical trial, and to examine potential mechanisms of treatment failure. In the phosphatase and tensin homolog deleted from chromosome 10 (PTEN)-null glioma cell lines U-87 and D-54, but not the oligodendroglioma cell line HOG (PTEN null), doses of rapamycin at the IC50 resulted in accumulation of cells in G1, with a corresponding decrease in the fraction of cells traversing the S phase as early as 24 h after dosing. All glioma cell lines tested had markedly diminished production of vascular endothelial growth factor (VEGF) when cultured with rapamycin, even at doses below the IC50. After 48 h of exposure to rapamycin, the glioma cell lines (but not HOG cells) showed downregulation of the membrane type-1 matrix metalloproteinase (MMP) invasion molecule. In U-87 cells, MMP-2 was downregulated, and in D-54 cells, both MMP-2 and MMP-9 were downregulated after treatment with rapamycin. Treatment of established subcutaneous U-87 xenografts in vivo resulted in marked tumor regression (P < 0.05). Immunohistochemical studies of subcutaneous U-87 tumors demonstrated diminished production of VEGF in mice treated with rapamycin. Gelatin zymography showed marked reduction of MMP-2 in the mice with subcutaneous U-87 xenografts that were treated with rapamycin as compared with controls treated with phosphatebuffered saline. In contrast, treatment of established intracerebral U-87 xenografts did not result in increased median survival despite inhibition of the Akt pathway within the tumors. Also, in contrast with our findings for subcutaneous tumors, immunohistochemistry and quantitative Western blot analysis results for intracerebral U-87 xenografts indicated that there is not significant VEGF production, which suggests possible deferential regulation of the hypoxia-inducible factor 1alpha in the intracerebral compartment. These findings demonstrate that the complex operational mechanisms of rapamycin against gliomas include cytostasis, anti-VEGF, and anti-invasion activity, but these are dependent on the in vivo location of the tumor and have implications for the design of a clinical trial.
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PMID:Mechanisms of action of rapamycin in gliomas. 1570 Dec 77

We previously identified constitutive Smad signaling in human melanoma cells despite resistance to transforming growth factor-beta (TGF-beta) control of cell proliferation. This led us to investigate the effect of inhibitory Smad7 overexpression on melanoma cell behavior. Using the highly metastatic cell line, 1205-Lu, we thus generated melanoma cell clones constitutively expressing Smad7, and their mock-transfected counterparts. Stable expression of Smad7 resulted in an inhibition of constitutive Smad2/3 phosphorylation, and in a reduced TGF-beta response of Smad3/Smad4-driven gene transactivation, as measured using transfected Smad3/4-specific reporter gene constructs. Smad7 overexpression, however, did not alter their proliferative capacity and resistance to TGF-beta-driven growth inhibition. On the other hand, expression of Smad7 efficiently reduced the capacity of human melanoma cells to invade Matrigel in Boyden migration chambers, while not affecting their motility and adhesion to collagen and laminin. Gelatin zymography identified reduced MMP-2 and MMP-9 secretion by Smad7-expressing melanoma cells as compared with their control counterparts. Smad7-expressing melanoma cells exhibited a dramatically reduced capacity to form colonies under anchorage-independent culture conditions, and, when injected subcutaneously into nude mice, were largely delayed in their ability to form tumors. These results suggest that TGF-beta production by melanoma cells not only affects the tumor environment but also directly contributes to tumor cell aggressiveness through autocrine activation of Smad signaling.
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PMID:Stable overexpression of Smad7 in human melanoma cells inhibits their tumorigenicity in vitro and in vivo. 1600 21

Caffeic acid phenethyl ester (CAPE) derived from honeybee propolis has been used as a folk medicine. Recent study also revealed that CAPE has several biological activities including antioxidation, anti-inflammation and inhibition of tumor growth. The present study investigated the effect of CAPE on tumor invasion and metastasis by determining the regulation of matrix metalloproteinases (MMPs). Matrix metalloproteinases, which are zinc-dependent proteolytic enzymes, play a pivotal role in tumor metastasis by cleavage of extracellular matrix (ECM) as well as nonmatrix substrates. On this line, we examined the influence of CAPE on the gene expression of MMPs (MMP-2, MMP-9, MT1-MMP), tissue inhibitor of metalloproteinase-2 (TIMP-2) and in vitro invasiveness of human fibrosarcoma cells. Dose-dependent decreases in MMP and TIMP-2 mRNA levels were observed in CAPE-treated HT1080 human fibrosarcoma cells as detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Gelatin zymography analysis also exhibited a significant down-regulation of MMP-2 and MMP-9 expression in HT1080 cells treated with CAPE compared to controls. In addition, CAPE inhibited the activated MMP-2 activity as well as invasion, motility, cell migration and colony formation of tumor cells. These data therefore provide direct evidence for the role of CAPE as a potent antimetastatic agent, which can markedly inhibit the metastatic and invasive capacity of malignant cells.
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PMID:Inhibitory effects of caffeic acid phenethyl ester on cancer cell metastasis mediated by the down-regulation of matrix metalloproteinase expression in human HT1080 fibrosarcoma cells. 1621 27

Matrix metalloproteinases (MMPs), zinc-dependent proteolytic enzymes, play a pivotal role in tumor metastasis by cleavage of extracellular matrix as well as non-matrix substrates. In this study, we examined the influence of DA-125, a new anthracyclin analog, on the gene expression of MMPs (MMP-2, MMP-9 and MT1-MMP), tissue inhibitor of metalloproteinases (TIMP-1 and TIMP-2) and in vitro invasiveness of human fibrosarcoma cells. Dose-dependent decreases of MMPs and TIMPs mRNA levels were observed in DA-125-treated HT1080 human fibrosarcoma cells detected by reverse transcriptase-polymerase chain reaction. Gelatin zymography analysis also showed a significant down-regulation of MMP-2 and MMP-9 expression in HT1080 cells treated with DA-125 compared to controls. In addition, DA-125 inhibited the invasion, motility and cell migration, and colony formation of tumor cells. These data, therefore, provide direct evidence for the role of DA-125 as a potential cancer chemotherapeutic agent, which can markedly inhibit the invasive capacity of malignant cells. Further, to clarify the transcriptional regulatory pathway, we primarily investigated the role of nuclear factor-kappaB (NF-kappaB) in the expression of MMPs by DA-125 in HT1080 cells. Electrophoretic mobility shift assay demonstrated that DA-125 modulates the binding activity of NF-kappaB. Using the luciferase reporter gene assay, a dose-dependent down-regulation of NF-kappaB-mediated luciferase expression was also observed. These results suggest that DA-125 down-regulates MMPs expression in HT1080 cells through the NF-kappaB-mediated pathway.
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PMID:Inhibitory effect of DA-125, a new anthracyclin analog antitumor agent, on the invasion of human fibrosarcoma cells by down-regulating the matrix metalloproteinases. 1627 Dec 63


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