Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The major cause of failure in the treatment of patients with solid malignancies is failure to prevent or control the spread of metastases. The metastatic process is a series of interrelated steps that must be accomplished before distant tumour foci can be established. Tumour cell motility is a complex process, which is involved in many of these steps. The mechanisms by which motility is stimulated and physically generated are complex and as yet poorly understood. Viewing the cell as a chemomechanical engine that relies on a tension based system for movement allows us to design chemotherapeutic strategies to inhibit tumour cell motility directly. Chemotherapeutic agents that block stimulation, interfere with cell-ECM interactions and interfere with cytoskeletal mechanics are already being tested. Further studies will be needed to define their efficacy.
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PMID:Cell motility as a chemotherapeutic target. 168 57

Immunohistochemical ABC method was used to study the distribution of fibronectin (FN), laminin (LN) and type I, III & IV collagens (Ic, IIIc, IVc) as well as estrogen and progesterone receptors (ER, PgR) in 20 breast carcinomas and 10 benign mammary lesions. LN and IVc were found in vascular and epithelial basement membranes (BMs), and FN was found in BMs and non-BMs. Ic and IIIc were only detected in stroma. LN, IVc and FN displayed continuous linear patterns in benign lesions where Ic and IIIc were sparsely and FN was intensively distributed. BMs in carcinomas were absent in varying degrees, Ic, IIIc and IVc exhibited heterogeneous staining and sparse FN distribution. No differences were noted in ECM staining patterns and ER & PgR levels in patients with and without lymph node metastases. The above data suggest that there is an obvious decrease of BM in breast cancer, and a heterogeneous change in Ic, IIIc and IVc due to stroma-tumor cell reactions, which may play important roles in limiting cancer growth. The immunodetection of BM changes in infiltrating ductal breast carcinoma does not help to evaluate the metastatic potential of tumors and is unrelated to the levels of ER and PgR.
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PMID:[Immunohistochemical detection of extracellular matrix in human breast carcinoma]. 816 85

Invasive cells show changes in adhesion, motility and the protease-antiprotease balance. In this paper the authors derive a model based on a continuum approach that describes the behaviour of the invasive cells. The invasive cells are studied in the context of their interaction with normal cells, noninvasive tumour cells, ECM proteins and the proteases. The authors briefly describe the methods of mathematical analysis used and then go on to highlight the biological inferences drawn from the mathematical analysis. Based on the results from the modelling the authors suggest that the movement of cells under the simultaneous effects of a haptotactic gradient and a concomitantly created chemotactic gradient is oscillatory both with respect to the speed of invasion and the wave profile of the invasive cells. They further demonstrate that the average speed of invasion can be computed as a measure of the phenotypic properties of the cell and the matrix. They use the model to suggest an intuitive explanation for the occurrence of noninvasion with high protease expression on the basis of chemotactic gradients that prevent invasion. The authors have studied the effect of the diffusivity of the protease on an invading cell and shown that increase in diffusivity initially results in enhanced invasion, but extreme increases in protease diffusivity can result in noninvasion.
Invasion Metastasis 1996
PMID:Biological inferences from a mathematical model for malignant invasion. 931 86

Matrix metalloproteinases (MMPs) play an important role in tumor cell invasion and metastasis. These processes require the dissolution of the basement membrane and invasion of the stromal matrix (ECM), and are mediated by MMPs. Consequently, MMP inhibitors may be attractive as new anticancer agents. To examine the potential contribution of collagenase-1 (MMP-1) in invasion of stromal matrix, we used the highly invasive and metastatic breast cancer cell line MDA-MB-231 as a model system. These cells express procollagenase-1 constitutively and this expression can be repressed by all-trans retinoic acid. Invasion of these cells into a collagen type I matrix was assessed by scanning electron microscopy (SEM), and was quantitated with a computer program and confocal laser scanning microscopy (CLSM). We found that MDA-MB-231 cells freely invaded the collagen type I matrix, suggesting that these cells possess a mechanism for activating the latent collagenase-1. In contrast, down-regulation of collagenase-1 expression by all-trans retinoic acid caused these cells to become less invasive. To confirm a role for collagenase-1 in mediating collagen type I invasion, assays were carried out in the presence of FN-439, an inhibitor of collagenase-1 enzyme activity. We found that in the presence of the proteinase inhibitor, invasion of type I collagen by MDA-MB-231 cells was also reduced. These results indicate that collagenase-1 produced by the breast tumor cells may enhance stromal matrix degradation by enabling the tumor cells to modulate their own invasive behavior, and suggest that decreasing collagenase-1 levels may be effective in breast cancer therapy.
Clin Exp Metastasis 1999 May
PMID:Human breast cancer cells activate procollagenase-1 and invade type I collagen: invasion is inhibited by all-trans retinoic acid. 1043 8

Understanding the molecular mechanisms of invasion and metastasis is crucial for the development of novel therapeutic strategies to treat metastases. Considerable studies revealed that the establishment of metastasis is the final outcome of a series of processes such as tumor growth, angiogenesis, tumor cell detachment and invasion of extracellular matrix. Each step of this multistep process is essential for tumor cell survival and establishment of secondary lesions and is regulated by interactions of tumor cells with host microenvironment. This review is focused on the molecular mechanisms involved in the regulation of this processes. The central role of adhesion molecules and ECM degrading proteinases in disruption of cell-cell and cell-ECM associations as well as degradation of extracellular matrix and basement membranes is emphasized.
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PMID:Invasion and metastasis in pancreatic cancer. 1043 84

Several studies have shown that extracellular matrix reduces chemotherapeutic drugs-induced apoptosis in small cell lung cancer cells, myelomas and gliomas. We have investigated the protective effect of defined extracellular matrix components and of extracellular matrix from different cell types (fibroblasts, hepatocytes and intestinal epithelial cells) on the toxicity of three types of chemotherapeutic drugs on colon cancer cells. Human colon cancer cell lines LS174T and LiM6 were plated on plastic, on hepatocyte-derived ECM or on stromal ECM and in the presence of the antimetabolite 5-fluorouracil (5-FU). the topoisomerase I inhibitor camptothecin and the topoisomerase II inhibitor etoposide. We determined IC50 for the drugs for each of these culture conditions. We also determined the expression of the anti-apoptotic proteins bcl-2 and bcl-x (L) under these culture conditions. We found that stromal ECM protected LiM6 cells from the toxicity of etoposide and LS174T, but not LiM6 cells, from the toxicity of camptothecin. Collagen 1, fibronectin and fibroblast-derived ECM rendered LiM6 cells, but not LS174T, more sensitive to the harmful effect of 5-FU. Both colon cell lines had increased expression of anti-apoptotic proteins bcl-2 and bcl-x(L) when cultured on the various ECMs and with the drugs, but there was no correlation between a protective ECM effect and expression of the anti-apoptotic proteins. Stromal-derived ECM may protect colon cancer cells from etoposide and camptothecin-induced apotosis, through a mechanism that is not bcl-2 or bcl-x(L) dependant.
Clin Exp Metastasis 2002
PMID:Stromal extracellular matrix reduces chemotherapy-induced apoptosis in colon cancer cell lines. 1191 83

Epithelial-mesenchymal transformation (EMT) is an important process in development that is characterized by loss of E-cadherin, beta-catenin relocalization, and acquisition of elongated cell shape and ability to invade ECM. beta-catenin has been shown to activate LEF-1 transcription during EMT induced in vitro by c-Fos. Here, we ask whether or not LEF-1 directly introduced into epithelial cells in an adenovirus construct can induce EMT. In normal epithelial cell lines, such as HCE and MDCK cells, that contain functional APC, nuclear beta-catenin induced by exogenous LEF-1 is rapidly exported and EMT is not induced. Leptomycin-B blocks beta-catenin nuclear export, but no EMT occurs due to toxicity. Addition of Wnt-1 to normal epithelial cell lines stabilizes cytoplasmic beta-catenin that LEF-1 then transports to nuclei, causing a small amount of EMT. Our experiments demonstrated, however, that overexpressed LEF-1 upregulates nuclear beta-catenin and promotes dramatic EMT in DLD-1 epithelial tumors that retain nuclear beta-catenin. This EMT is reversible if the LEF-1 virus is removed. Thus, our results demonstrate that LEF-1 can induce EMT directly when its transcription activity is activated by stable nuclear beta-catenin. Normal adult epithelial cells appear to use APC to keep beta-catenin out of the nucleus, thereby avoiding pathologies such as metastases due to LEF/beta-catenin-induced EMT.
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PMID:Direct evidence for a role of beta-catenin/LEF-1 signaling pathway in induction of EMT. 1209 32

Matrix metalloproteinases (MMPs), zinc dependent proteolytic enzymes, cleave extracellular matrix (ECM: collagen, laminin, firbronectin, etc) as well as non-matrix substrates (growth factors, cell surface receptors, etc). The deregulation of MMPs is involved in many diseases, such as tumor metastasis, rheumatoid arthritis, and periodontal disease. Metastasis is the major cause of death among cancer patients. In this review, we will focus on the roles of MMPs in tumor metastasis. The process of metastasis involves a cascade of linked, sequential steps that involve multiple host-tumor interactions. Specifically, MMPs are involved in many steps of tumor metastasis. These include tumor invasion, migration, host immune escape, extravasation, angiogenesis, and tumor growth. Therefore, without MMPs, the tumor cell cannot perform successful metastasis. The activities of MMPs are tightly regulated at the gene transcription levels, zymogen activation by proteolysis, and inhibition of active forms by endogenous inhibitors, tissue inhibitor of metalloproteinase (TIMP), and RECK. The detailed regulations of MMPs are described in this review.
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PMID:Roles of matrix metalloproteinases in tumor metastasis and angiogenesis. 1254 83

The defining characteristic of a tumor cell is its ability to escape the constraints imposed by neighboring cells, invade the surrounding tissue, and metastasize to distant sites. This invasive property of tumor cells is dependent on activation of proteases at the cell surface. Most cancer cells secrete the urokinase-type plasminogen activator, which converts cell-bound plasminogen to plasmin. Here we address the issue of whether the plasminogen binding protein, p11, plays a significant role in this process. Transfection of human HT1080 fibrosarcoma cells with the human p11 gene in the antisense orientation resulted in a loss of p11 protein from the cell surface and concomitant decreases in cellular plasmin production, ECM degradation, and cellular invasiveness. The transfected cells demonstrated reduced development of lung metastatic foci in SCID mice. In contrast, HT1080 cells transfected with the p11 gene in the sense orientation displayed increased cell surface p11 protein and concomitant increases in cellular plasmin production, as well as enhanced ECM degradation and enhanced cellular invasiveness. The p11 overexpressing cells showed enhanced development of lung metastatic foci. These data establish that changes in the extracellular expression of the plasminogen receptor protein, p11, dramatically affect tumor cell-mediated pericellular proteolysis.
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PMID:p11 regulates extracellular plasmin production and invasiveness of HT1080 fibrosarcoma cells. 1255 2

We investigated alpha1-antichymotrypsin (ACT) gene expression in xenograft tumors generated by two isogenic human breast cancer cell lines derived from the same parent, MDA-MB-435, which display opposite metastatic behaviors. Microarray and real-time PCR experiments showed an overexpression of this serine protease inhibitor in the metastatic tumors (M-4A4T) and its derived metastases (M4-Mets) compared with the weakly metastatic tumors (NM-2C5T), and its release into the blood was confirmed by western-blotting. However, functional assays in vivo using genetically engineered tumor cells demonstrated that ACT up-regulation was not, by itself, responsible for the metastatic phenotype. We also made observations that ACT gene regulation was sensitive to tumor-host interactions: inoculation of these lines into the mouse mammary gland greatly increased ACT production and accentuated the intrinsic difference observed when they are cultured in vitro. Sensitivity of tumor cells to their environment was further analyzed by in vitro experiments, which demonstrated that a purified ECM environment and soluble components from normal host mammary cells were both able to significantly promote ACT expression. In addition, we took advantage of the xenogeneic nature of the model to measure ACT expression by the host cells (mouse) and the tumor cells (human) within the neoplasm using species-specific primers in real-time PCR experiments. It was found that the presence of tumor cells, irrespective of their metastatic capabilities, induced local ACT production by host cells at the primary and secondary tumor sites. Thus, this work indicates that there is a specific association of ACT overexpression with the metastatic phenotype in our breast cancer metastasis model. Moreover, because of the xenogeneic nature of our system, we were able to provide evidence of tumor-host reciprocal regulation of ACT production.
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PMID:Tumor-host interactions contribute to the elevated expression level of alpha1-antichymotrypsin in metastatic breast tumor xenografts. 1581 Nov 32


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