Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0178874 (tumor progression)
 40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Zinc-alpha(2)-glycoprotein (Znalpha(2)gp) is widely distributed in body fluids and epithelia. Its expression in stratified epithelia increases with differentiation. We previously showed that Zn alpha(2)gp has ribonuclease activity, and that squamous tumor cells grown on a matrix of Znalpha(2)gp were growth-inhibited. Here we demonstrate, both by adding Znalpha(2)gp to the culture medium and, more unequivocally, by stably transfecting SiHa cells with Znalpha(2)gp cDNA, that the introduction of Znalpha(2)gp into SiHa tumor cells reduces proliferation. In response to Znalpha(2)gp, we find an accumulation of the cell population in G(2)/M by flow cytometry, paralleling the reduction of proliferation. In order to distinguish growth inhibition by cell cycle arrest from that produced by apoptosis or differentiation, we examine by RT-PCR how Znalpha(2)gp affects the expression of genes commonly used as markers of these properties. No changes are observed for PCNA, p53, c-myc, or bcl-2. Only cdc2 expression responds to Znalpha(2)gp, with a reduction of up to over a factor of two. Cdc2 is the only cyclin-dependent kinase regulating the G(2)/M transition without redundancy and is required as a rate-limiting step in the cell cycle. Its increased expression has been directly linked to increased proliferation and decreased differentiation of advanced tumors; conversely, its downregulation by Znalpha(2)gp might hinder tumor progression. J. Cell. Biochem. Suppl. 36: 162-169, 2001.
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PMID:Zinc-alpha(2)-glycoprotein hinders cell proliferation and reduces cdc2 expression. 1145 81

Fibronectin (FN) is a glycoprotein component of connective tissue. It is involved in cancer progression. FN plays a role in non-neoplasmatic lung pathology in which fibronectin gene polymorphisms (RFLPs) have been studied. The aim of our work was to evaluate the frequency of two of fibronectin RFLPs: genotypes AB, AA, BB (HaeIII) and CD, CC, DD (MspI) in patients with lung cancer. The studied group consisted of 63 patients with squamous cell lung cancer and 53 controls without any malignant or proliferative disease. There were no statistically significant differences in the distribution of studied genotypes between lung cancer patients and controls.
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PMID:Fibronectin gene polymorphism in patients with lung cancer. 1160 51

Non-small cell lung cancer (NSCLC) is a systemic illness. The majority of newly diagnosed patients depend on systemic chemotherapy to improve outcome. Among the new chemotherapeutic agents recently tested, paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) has shown convincing single-agent activity in advanced NSCLC. The two initial phase II studies using paclitaxel alone showed a 1-year survival rate of 40%, comparable to that seen with combination regimens. Paclitaxel/carboplatin is one of several standard regimens for patients with stage IIIB to IV disease. It is as effective as any other new agent/platinum combination studied to date; it is easy to administer and well tolerated. Identification of the molecular and genetic events involved in each step of tumor progression seems to be crucial both to understanding lung cancer and for the development of new pharmacologic compounds that target specific cellular processes affecting growth and proliferation. An innovative strategy is to combine established chemotherapy with these new compounds. Resistance to available chemotherapy drugs is the major obstacle to effective chemotherapy. Genetic abnormalities could play a role in outlining some patterns of chemoresistance. Acquired resistance to paclitaxel can be mediated by several mechanisms, including overexpression of p-glycoprotein, altered expression of beta-tubulin isotypes, intrinsic or acquired mutations in beta-tubulin, and expression of novel genes. Beta-tubulin mutations were recently identified in 33% of 49 NSCLC patients, none of whom had an objective response to paclitaxel treatment. Cisplatin resistance is associated with several molecular alterations, including overexpression of metallothionein and the mRNA level of the excision repair cross-complementing (ERCC1) gene. Early detection of circulating cancer cells in peripheral blood would enable more accurate lung cancer staging. Furthermore, sequential measurements of DNA concentration may be used to monitor the effects of therapy. Serum DNA can be used as a surrogate for detecting genetic abnormalities and as a potential guide for customizing treatment. We analyzed the presence of beta-tubulin mutations in serum DNA from NSCLC patients and from healthy individuals. Beta-tubulin mutations were detected in 42% of the 131 patients and in none of the control group. Several clinical studies are proposed to develop more customized approaches in lung cancer.
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PMID:Predicting response to paclitaxel/carboplatin-based therapy in non-small cell lung cancer. 1160 82

Matrix metalloproteinases (MMPs) are essential for proper extracellular matrix remodeling. We previously found that a membrane-anchored glycoprotein, RECK, negatively regulates MMP-9 and inhibits tumor invasion and metastasis. Here we show that RECK regulates two other MMPs, MMP-2 and MT1-MMP, known to be involved in cancer progression, that mice lacking a functional RECK gene die around E10.5 with defects in collagen fibrils, the basal lamina, and vascular development, and that this phenotype is partially suppressed by MMP-2 null mutation. Also, vascular sprouting is dramatically suppressed in tumors derived from RECK-expressing fibrosarcoma cells grown in nude mice. These results support a role for RECK in the regulation of MMP-2 in vivo and implicate RECK downregulation in tumor angiogenesis.
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PMID:The membrane-anchored MMP inhibitor RECK is a key regulator of extracellular matrix integrity and angiogenesis. 1174 14

Thrombospondin-1 (TSP-1) is a matricellular glycoprotein that influences cellular phenotype and the structure of the extracellular matrix. These effects are important components of the tissue remodeling that is associated with angiogenesis and neoplasia. The genetic mutations in oncogenes and tumor suppressor genes that occur within tumor cells are frequently associated with decreased expression of TSP-1. However, the TSP-1 that is produced by stromal fibroblasts, endothelial cells and immune cells suppresses tumor progression. TSP-1 inhibits angiogenesis through direct effects on endothelial cell migration and survival and through indirect effects on growth factor mobilization. TSP-1 that is present in the tumor microenvironment also acts to suppress tumor cell growth through activation of transforming growth factor beta in those tumor cells that are responsive to TGF beta. In this review, the molecular basis for the role of TSP-1 in the inhibition of tumor growth and angiogenesis is summarized.
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PMID:Thrombospondin-1 as an endogenous inhibitor of angiogenesis and tumor growth. 1200 65

Fibronectin (Fn) was the first 'structural' glycoprotein intensively studied as an ubiquitous matrix component of early phylogenetic appearance. Its age-dependent increase in plasma and tissues may be accompanied in pathological states, especially in tumor growth, by its proteolytic breakdown by a number of neutral proteases. It was also shown that several of its proteolytic breakdown products exhibit unexpected and mostly harmful biological activities. The first of these effects was a potentiation of malignant transformation. Some fragments had proteolytic activity, others behaved as proinflammatory agents stimulating IL-1 and collagenolytic MMP up-regulation. This matricryptic potential of Fn was followed by several other examples of proteolytic production of biologically active peptides. The study of solid human tumors showed among the early signs of malignant transformation the fragmentation of pericellular Fn, concommitent with the increase of its production by the peritumoral stroma. These results should encourage further investigations concerning the potential importance of Fn production and breakdown during cancer progression.
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PMID:Fibronectin in malignancy. 1208 49

The adverse prognosis associated with malignant astrocytomas (MA) is due in part to the development of resistance by the tumor to chemo- and radiotherapy-induced cytotoxic damage. The mechanisms of resistance are poorly understood but function at the level of the endothelial cell, the blood-brain barrier and the neoplastic cell itself. The classic examples of drug resistance proteins, such as the p-glycoprotein/multidrug resistance protein 1, have been identified within MA biopsy specimens. However, it is questionable to what degree, if at all, these proteins contribute directly to the evolution and prognosis of the MA. Surprisingly, there are specific genes, not traditionally associated with resistance, which appear increasingly relevant to both tumor progression and insensitivity to cytotoxic damage. These genes are involved in cell cycle regulation, and include the retinoblastoma susceptibility gene (Rb), the tumor suppressor gene p53, as well as those encoding the cyclins, their kinases and inhibitors. The interaction between the products of these genes and intratumoral environmental factors appears to involve a dynamic and prognostically adverse selection process. It is from this perspective that the mechanism(s) of hypoxic-ischaemic selection for resistance and its therapeutic repercussions will be analyzed.
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PMID:The molecular genetics of therapeutic resistance in malignant astrocytomas. 1217 77

Alpha2-HS glycoprotein (fetuin) is a major plasma glycoprotein predominantly synthesized by the liver. We have previously demonstrated that human fetuin produced by hepatocellular carcinoma cells can activate the matrix metalloproteinase MMP-9 (gelatinase-B). Stromelysin-1 (MMP-3) is over-expressed in murine skin tumors and is associated with a metastatic cell phenotype. We hypothesize that fetuin plays a role in tumor progression of cell types which by themselves do not have the ability to express fetuin. Immunohistochemical staining revealed that fetuin surrounds the tumor cells in murine squamous cell carcinoma tumor specimens, similar to the expression pattern previously seen for MMP-3. The physical association of fetuin and MMP-3 was demonstrated by immunoprecipitation of radiolabeled fetuin by antibodies to MMP-3. Fetuin facilitates the conversion of pro-MMP-3 to its active form, although this effect is indirect. The association of iodinated fetuin to the cell surface of intact cultured cells derived from a murine tumor with squamous (B9) and spindle (A5) morphologies was determined by binding experiments and Scatchard analysis. Fetuin binds with Bmax values in the range of 1.26-2.1 (mean = 1.7) fmol/1 x 10(5) cells for A5 cells, and 1.5-1.7 (mean = 1.6) fmol/1 x 10(5) cells for B9 cells. The mean KD was 0.46+/-0.19 nmol for both A5 and B9 cells. Our data therefore are consistent with the model that fetuin binds to the cell surface of tumor cells and acts to localize and anchor other molecules important during tumor progression to the plasma membrane.
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PMID:Interactions of alpha2-HS-glycoprotein (fetuin) with MMP-3 and murine squamous cell carcinoma cells. 1237 Jul 42

Targeted gene mutations in mice that cause deficiencies in protein glycosylation have revealed functions for specific glycans structures in embryogenesis, immune cell regulation, fertility and cancer progression. UDP-N-acetylglucosamine:alpha-6-D-mannoside beta1,6 N-acetylglucosaminyltransferase V (GlcNAc-TV or Mgat5) produces N-glycan intermediates that are elongated with poly N-acetyllactosamine to create ligands for the galectin family of mammalian lectins. We generated Mgat5-deficient mice by gene targeting methods in embryonic stem cells, and observed a complex phenotype in adult mice including susceptibility to autoimmune disease, reduced cancer progression and a behavioral defect. We found that Mgat5-modified N-glycans on the T cell receptor (TCR) complex bind to galectin-3, sequestering TCR within a multivalent galectin-glycoprotein lattice that impedes antigen-dependent receptor clustering and signal transduction. Integrin receptor clustering and cell motility are also sensitive to changes in Mgat5-dependent N-glycosylation. These studies demonstrate that low affinity but high avidity interactions between N-glycans and galectins can regulate the distribution of cell surface receptors and their responsiveness to agonists.
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PMID:UDP-N-acetylglucosamine:alpha-6-D-mannoside beta1,6 N-acetylglucosaminyltransferase V (Mgat5) deficient mice. 1241 26

CA125 is an ovarian cancer antigen whose recently elucidated primary structure suggests that CA125 is a giant mucin-like glycoprotein present on the cell surface of tumor cells. Here, we establish a functional link between CA125 and beta-galactoside-binding, cell-surface lectins, which are components of the extracellular matrix implicated in the regulation of cell adhesion, apoptosis, cell proliferation and tumor progression. On the basis of mass spectrometry and immunological analyses, we find that CA125 is a counter receptor for galectin-1, as both soluble and membrane-associated fragments of CA125 derived from HeLa cell lysates are shown to bind specifically to human galectin-1 with high efficiency. This interaction is demonstrated (1) to depend on beta-galactose-terminated, O-linked oligosaccharide chains of CA125, (2) to be preferential for galectin-1 versus galectin-3 and (3) to be regulated by the cellular background in which CA125 is expressed. Despite lacking a conventional signal peptide, a CA125 C-terminal fragment of 1148 amino acids, representing less than 10% of the full-length protein, retains the ability to integrate into secretory membranes such as the endoplasmic reticulum (ER) and the Golgi, and is targeted to the plasma membrane by conventional secretory transport. As demonstrated by a novel assay that reconstitutes non-conventional secretion of galectin-1 based on fluorescence-activated cell sorting (FACS), we find that tumor-derived HeLa cells expressing endogenous CA125 present more than ten times as much galectin-1 on their surface compared with non-tumor-derived, CA125-deficient CHO cells. Intriguingly, both the galectin-1 expression level and the cell-surface binding capacity for galectin-1 are shown to be similar in CHO and HeLa cells, suggesting that CA125 might be a factor involved in the regulation of galectin-1 export to the cell surface.
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PMID:The cancer antigen CA125 represents a novel counter receptor for galectin-1. 1261 72


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