Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.73 (urokinase-type plasminogen activator)
 10,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The macrophage colony-stimulating factor (CSF-1) is best known as a hematopoietic cytokine important to macrophage activation. Recently, the importance of CSF-1 and its receptor (encoded by the c-fms proto-oncogene) in epithelial ovarian cancer has also been recognized, with overexpression of CSF-1 denoting poor prognosis in ovarian cancer patients. During macrophage activation, CSF-1 promotes urokinase-type plasminogen activator (uPA) activity; in macrophages and in malignant cells of lung, breast, colon, and prostatic origin, uPA activity is strongly correlated with the ability to invade and, in the malignant cells, to metastasize. While there is clear evidence of CSF-1 and uPA expression in primary and metastatic ovarian cancer, the significance of their expression to invasion of these cells has not been explored. We find that all of our ovarian cancer cell lines which we have studied co-express CSF-1 and uPA transcripts and protein. Urokinase expression in these ovarian cancer cell lines correlates with the degree of tumorigenicity in nude mice, with the most virulent tumor resulting from Hey cells, a strong expressor of uPA. We studied the invasion of these primary and established ovarian cancer cells through a Matrigel (reconstituted basement membrane matrix) barrier. The ability of ovarian cancer cells to invade is strongly correlated with endogenous CSF-1 expression (Pearson's correlation, r = 0.91; P = 0.01). A total of 0.90 +/- 0.16% of Bix3 cells (very weak expressor of CSF-1) invaded through the barrier, in contrast to 6.95 +/- 0.75% of Hey cells (strong CSF-1 expressor) and 10.44 +/- 2.33% of Bixler cells (the strongest CSF-1 expressor). We studied the ability of two of the cell lines to invade human laminin and type IV collagen (Bix3, a weak invader of Matrigel, and Hey, a strong invader), to determine (a) whether our results on a Matrigel matrix may represent a relevant model for invasion in humans and (b) whether there is a potential confounding effect from the cytokines and proteases in Matrigel. On this human simple matrix, we confirm that Bix3 is a weakly invasive cell line (0.33 +/- 0.04% invasion) which contrasted to the strongly invasive Hey cell line (8.51 +/- 0.47%). Treatment of Bix3 cells with exogenous CSF-1 stimulates percentage of invasion by 2-fold and results in a similar increase in the level of uPA transcripts and cellular associated uPA antigen. Furthermore, cell surface-bound uPA increased from 74% in the absence of CSF-1 to 100% (fully saturated) in the presence of CSF-1.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Macrophage colony-stimulating factor mediates invasion of ovarian cancer cells through urokinase. 788 68

Invasion of tissue by macrophages and implantation into the uterine wall by placental trophoblasts are known to be regulated by the macrophage colony-stimulating factor (CSF-1) and its receptor (CSF-1R, the product of the c-fms proto-oncogene). Recently, the clinical importance of CSF-1 and CSF-1R in invasive breast carcinoma has been recognized, but the significance of coexpression of CSF-1 and CSF-1R in mammary epithelial cell invasion has not been explored. In the present study, we investigated the invasive potential of a noninvasive, CSF-1R-negative, mouse mammary epithelial cell line (HC11) expressing a high level of CSF-1, which was stably transfected with the mouse wild-type CSF-1R. Compared with parental cells, transfected cells expressing a wild-type CSF-1R invaded 100-fold more efficiently through a barrier of reconstituted basement membrane (Matrigel) and formed colonies in soft agar, whereas the cellular growth rate was only slightly increased. Analysis of cell-conditioned medium by zymography and quantitative enzyme activity assays showed that clones transfected with a wild-type CSF-1R expressed significantly higher levels of urokinase-type plasminogen activator than did untransfected clones. Furthermore, after injection into the tail veins of BALB/c mice, CSF-1R-expressing clones also produced a 10-fold higher incidence of lung tumors than the parental cell line. We also analyzed HC11 clones transfected with CSF-1R mutated at two major autophosphorylation sites (Tyr-->Phe807 and Tyr-->Phe721). Mutation at Tyr807 eradicated the stimulatory effect of Fms expression on the invasive ability of HC11 cells and substantially reduced the metastatic potential of the transfected clones but did not alter the Fms-induced anchorage-independent growth in soft agar. In contrast, mutation at Tyr721 of Fms had no effect on invasion as measured in the in vitro assay but markedly abolished Fms-induced colony formation in soft agar and eradicated the metastatic potential of the transfected clones. Our results suggest that expression of CSF-1R can facilitate cellular invasion and anchorage-independent growth in mammary epithelial cells, and these two processes are independently regulated by separate phosphotyrosine sites of CSF-1R.
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PMID:Independent regulation of invasion and anchorage-independent growth by different autophosphorylation sites of the macrophage colony-stimulating factor 1 receptor. 897 Nov 79

Colony stimulating factor (CSF-1) and its receptor (CSF-1R, product of c-fms proto-oncogene) were initially implicated as essential for normal monocyte development as well as for trophoblastic implantation. However, recent findings have suggested that CSF-1 and CSF-1R might have additional roles in mammary gland development during pregnancy and lactation. Studies with osteopetrotic (op-/op-) mice, which bear a specific mutation that inactivates the CSF-1 gene, demonstrated that op-/op- mothers are incapable of normal milk production due to the incomplete development of their mammary glands during pregnancy. Also, significant increases in the levels of CSF-1 and CSF-1R proteins are observed in the epithelial cells of mammary gland during pregnancy and lactation. In vitro studies investigating the effect of the three major lactogenic hormones (prolactin, insulin, and glucocorticoids) on the expression of CSF-1 and CSF-1R have demonstrated that expression of CSF-1 can be regulated by prolactin and insulin whereas CSF-1R expression is regulated by glucocorticoids. This apparent role for CSF-1/CSF-1R in normal mammary gland development is very intriguing because this receptor/ligand pair has also been found to be important in the biology of breast cancer, where they regulate tumor cell invasion by a urokinase-dependent mechanism. This review aims to summarize recent findings on the role of CSF-1 and its receptor in normal and neoplastic mammary development which may elucidate potential relationships of growth factor-induced biological changes in the breast during pregnancy and tumor progression.
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PMID:The role of CSF-1 in normal and neoplastic breast physiology. 989 62

The phosphatase and tensin homology deleted on chromosome 10 (PTEN) is a tumor suppressor gene with sequence homology to tyrosine phosphatases and the cytoskeletal proteins tensin and auxilin. PTEN has recently been shown to inhibit cell migration and the spreading and formation of focal adhesions. This study investigated the role of PTEN in carcinoma invasion in a lung-cancer cell line and examined the downstream genes regulated by PTEN. We have previously established a cell-line model in human lung adenocarcinoma with different invasive abilities and metastatic potentials. Examining PTEN gene expression in these cell lines, we found that a homozygous deletion in exon 5 is associated with high invasive ability. We then constructed stable constitutive and inducible wild-type PTEN-overexpressed transfectants in the highly invasive cell line CL(1-5). We found that an overexpression of PTEN can inhibit invasion in lung cancer cells. To further explore the downstream genes regulated by PTEN, a high-density complementary DNA (cDNA) microarray technique was used to profile gene changes after PTEN overexpression. Our results indicate a panel of genes that can be modulated by PTEN. PTEN overexpression downregulated genes, including integrin alpha(6), laminin beta(3), heparin-binding epidermal growth factor-like growth factor, urokinase-type plasminogen activator, myb protein B, Akt2, and some expressed sequence tag (EST) clones. In contrast, PTEN overexpression upregulated protein phosphatase 2A1B, ubiquitin protease (unph), secreted phosphoprotein 1, leukocyte elastase inhibitor, nuclear factor-kappaB, cyclic adenosine monophosphate response element binding protein, DNA ligase 1, heat shock protein 90, and some EST genes. Northern hybridization and flow cytometry analysis also confirmed that PTEN overexpression results in the reduced expression of the integrin alpha(6) subunit. The results of this study indicate that PTEN overexpression may inhibit lung cancer invasion by downregulation of a panel of genes including integrin alpha(6). The cDNA microarray technique may be an effective tool to study the downstream function of a tumor suppressor gene.
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PMID:Profiling the downstream genes of tumor suppressor PTEN in lung cancer cells by complementary DNA microarray. 1097 Aug 13