Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1326912 (tumorigenesis)
 57,481 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cytokines are potent modulators of the physiological immune response. A number of reactive processes are associated with a deregulation of this cytokine expression. Animal models with transgenic mice or transfection experiments have shown that an autocrine or paracrine pathway might be involved in tumor progression and/or tumorigenesis. The study of cytokine expression in malignant lymphomas showed a heterogeneous expression pattern with a number of cases which quantitatively show indications for a marked deregulation of the cytokine expression. The expression od IL-7 and IL-9 seem to be special features of Hodgkin's disease and large cell anaplastic lymphomas. Transfection experiment with IL-9 into mouse T cells results in an autocrine loop and tumorigenesis of the transfected cells. These tumors share a number of similarities to Hodgkin's disease and large cell anaplastic lymphomas in human.
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PMID:[Cytokines and malignant lymphomas]. 128 79

Interleukin 6 (IL-6) is a polyfunctional cytokine which regulates the immune response, the acute-phase reaction and haemopoiesis. IL-6 plays a critical role in differentiation of B cells into plasma cells, and is a potent growth factor for plasmacytomas and myelomas. A relationship between IL-6 and polyclonal plasma cell abnormalities has been demonstrated. Abnormal production of IL-6 was first suggested to be related to hypergammaglobulinaemia with autoantibody production in patients with cardiac myxoma. A role of IL-6 in the generation of plasmacytoma has also been indicated. In support of these clinical and experimental observations, we demonstrated that transgenic C57BL/6 mice carrying the human IL-6 gene showed a massive polyclonal plasmacytosis with production of autoantibodies. However, the tumour was not transplantable to syngeneic animals. Susceptibility to pristane-induced plasmacytomagenesis is genetically determined--pristane can induce plasmacytomas in BALB/c but not in C57BL/6 mice. IL-6 transgenic C57BL/6 mice were backcrossed to BALB/c mice to elucidate the genetic influence on plasmacytomagenesis. Transplantable monoclonal plasmacytoma with a t(12;15) chromosomal translocation was generated in some of the backcrossed mice, indicating that IL-6 plays a key role in the multistep oncogenesis of plasma cell neoplasia.
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PMID:The role of interleukin 6 in plasmacytomagenesis. 142 13

Deregulation of the proto-oncogene MYC by specific chromosomal translocations has been shown to be essential but not sufficient for the development of Burkitt's lymphoma (BL). To identify other genes which either mark important steps in tumorigenesis or which reflect the cellular differentiation state of BL cells we have compared tumor cells to immortalized lymphoblastoid B cells by subtractive hybridization. We have identified a complementary DNA clone which encodes a novel member of the superfamily of GTP-binding (G) protein-coupled receptors, designated BLR1. The corresponding mRNA is expressed in BL and lymphatic tissues but not in other cell lines either of the B cell lineage or of other hematopoietic or non-hematopoietic origin. This exclusive expression of BLR1 and the oncogenic potential of this receptor class supports the hypothesis that BLR1 exerts a regulatory function in BL lymphomagenesis and/or B cell differentiation. Moreover, the protein sequence is highly related to that of receptors for the cytokine interleukin (IL)-8 and other neutrophil chemoattractants. We conclude that BLR1 may represent a potential candidate involved in the process of physiologic trafficking, cell-cell interactions, and activation of mature B lymphocytes in lymphatic tissues.
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PMID:Differentiation-specific expression of a novel G protein-coupled receptor from Burkitt's lymphoma. 142 7

LD78 is a small secreted protein that has a sequence similar to a number of other polypeptides, including murine macrophage inflammatory protein 1 alpha (MIP-1 alpha), interleukin 8 (IL-8), Act-2, monocyte chemoattractant protein 1 (MCP-1), and others. These polypeptides are members of a novel cytokine superfamily that is involved in the inflammatory response, wound healing, hematopoiesis, and tumorigenesis. Specific receptors for purified clonal LD78 protein were measured using four cell lines (HL-60, U937, Jurkat, and MJ). 125I-labeled recombinant LD78 bound most efficiently to U937 cells. We therefore characterized the receptors as being on the surface of U937 cells. Binding reached an equilibrium after incubation for 60 min at 4 degrees C. Scatchard analysis showed that there were two classes of binding sites on U937 cells, high affinity sites (Kd = 5.3 x 10(-9) M) and low affinity sites (Kd = 9.3 x 10(-8) M), with the average number of binding sites per cell being approximately 30,000 and approximately 90,000, respectively. These receptors for LD78 were distinct from the receptors for gamma-IFN and for IL-8. SDS-PAGE analysis of chemically crosslinked 125I-labeled LD78 receptor complexes identified a single band of 52 kDa. The ability to detect specific LD78 receptors should prove valuable in efforts to molecularly clone these receptors and to dissect the biological actions of LD78.
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PMID:Identification and characterization of specific receptors for the LD78 cytokine. 151 Nov 63

Interleukin-6, IL-6, is a pleiotropic cytokine which plays a central role in defense mechanisms, including the immune response, acute phase reaction and hematopoiesis. Abnormal expression of the IL-6 gene has been suggested to be involved in the pathogenesis of a variety of diseases, especially rheumatoid arthritis, Castleman's disease, mesangial proliferative glomerulonephritis, multiple myeloma and Kaposi's sarcoma. In the case of multiple myeloma and Kaposi's sarcoma, the existence of an IL-6-IL-6 receptor autocrine loop has been implicated in the oncogenesis process. On the other hand, IL-6 has a potent anti-tumor activity against certain types of tumors. This anti-tumor effect is mediated by in vivo induction of tumor specific cytotoxic T cells and in part by a growth inhibitory activity of IL-6.
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PMID:The evidence for interleukin-6 as an autocrine growth factor in malignancy. 164 91

Transgenic animal technology has been useful for the direct demonstration of the tumorigenic potential of oncogenes in vivo. Over the past eight years a wide variety of oncogenes and proto-oncogenes from viral and cellular sources have been inserted into the germline of mice with subsequent development of neoplasia. Many of the published reports describe similarities between morphologic features of the transgenic mice tumors and those occurring naturally in humans. We discuss the morphologic features of selected transgenic models carrying viral genes and review their applicability to investigations directed toward understanding cancer in general and specifically gastric cancer, neurofibromatosis and leukemia. Examples of the impact of nutrition, interaction with growth factors and initiation with chemical carcinogens are presented. In one of the models functional similarities to the mechanism of oncogenesis in human T-cell leukemia virus type-1 (HTLV-1) lymphoma may exist with activation of cytokine production and subsequent autocrine stimulation. The transgenic model of proximal gastric cancer demonstrates features similar to those seen in carcinogen-induced neoplasia. These studies underscore the vast potential of transgenic models for inquiry into the genetic and epigenetic basis of human carcinogenesis. However, many features of transgenic cancer models differ from cancer in humans and the specific criteria for judging the value of transgenic models remain unclarified. For example, although the tumors arising in the HTLV-1 Tax transgenic mice show numerous similarities to human neurofibromatosis including development of lesions of the iris, the similarities do not necessarily extend to the molecular involvement of neurofibromatosis-1 (NF-1), a gene with structural and functional homology to GTPase activating proteins. Transgenic experiments of the future will ask questions beyond whether a particular gene is capable of initiating the neoplastic process. The ability to construct systems in vivo with a defined starting point that facilitate further controlled manipulation of events resulting in cancer provide great opportunities to dissect the various molecular pathways involved in such a process. Therefore, gene knockout experiments and disruption of gene function will further enhance our ability to understand the multi-factorial process of tumor development.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Transgenic models of human cancer. 166 87

TSG-6 cDNA was isolated by differential screening of a lambda cDNA library prepared from tumor necrosis factor (TNF)-treated human diploid FS-4 fibroblasts. We show that TSG-6 mRNA was not detectable in untreated cells, but became readily induced by TNF in normal human fibroblast lines and in peripheral blood mononuclear cells. In contrast, TSG-6 mRNA was undetectable in either control or TNF-treated human vascular endothelial cells and a variety of tumor-derived or virus-transformed cell lines. The sequence of full-length TSG-6 cDNA revealed one major open reading frame predicting a polypeptide of 277 amino acids, including a typical cleavable signal peptide. The NH2-terminal half of the predicted TSG-6 protein sequence shows a significant homology with a region implicated in hyaluronate binding, present in cartilage link protein, proteoglycan core proteins, and the adhesion receptor CD44. The most extensive sequence homology exists between the predicted TSG-6 protein and CD44. Western blot analysis with an antiserum raised against a TSG-6 fusion protein detected a 39-kD glycoprotein in the supernatants of TNF-treated FS-4 cells and of cells transfected with TSG-6 cDNA. Binding of the TSG-6 protein to hyaluronate was demonstrated by coprecipitation. Our data indicate that the inflammatory cytokine (TNF or IL-1)-inducible, secretory TSG-6 protein is a novel member of the family of hyaluronate binding proteins, possibly involved in cell-cell and cell-matrix interactions during inflammation and tumorigenesis.
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PMID:A novel secretory tumor necrosis factor-inducible protein (TSG-6) is a member of the family of hyaluronate binding proteins, closely related to the adhesion receptor CD44. 173 Jul 67

It is well known that expression of certain growth factors leads to tumorigenesis. However, the role of growth inhibitory molecules in this process is less certain. During the last few years several cytokines with growth inhibitory properties have been identified. In spite of the production of these cytokines by the body's immune system, the growth and progression of the tumor continue. In order to understand the mechanisms by which tumor escapes the host defense system, we have used lymphotoxin (LT), a lymphocyte-derived cytokine that is known to selectively inhibit the growth of certain tumor cells. The effect of LT was investigated on NIH-3T3 mouse fibroblast cells that are highly sensitive to its cytotoxic effects and are also tumorigenic in nude mice. On exposure to 10 units/ml of LT, 50% of these cells are killed within 24 h. A stable variant of NIH-3T3 cells that is completely resistant (LT-R) to even 10,000-fold higher concentration of the cytokine than that of sensitive cells (LT-S) was isolated in vitro by repeated exposure to LT. Both LT-S and LT-R displayed similar characteristics when grown both as a monolayer and in soft agar. No significant difference in LT receptor number or affinity between the two cell types was observed. It was not possible to overcome the resistance to LT by the addition of interferon-gamma but the resistance could be overcome by the presence of various chemotherapeutic agents suggesting a difference in the mechanism of action of these two agents.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:In vitro selection of NIH-3T3 cells for resistance to lymphotoxin induces resistance to activated macrophages and enhances tumorigenicity in vivo. 176 39

Reduced expression and/or somatic allelic deletion of nm23 is associated with high metastatic potential in several types of rodent tumors and human breast and colorectal carcinomas. Transfection of murine nm23-1 cDNA into highly metastatic murine K-1735 TK melanoma cells results in a reduced incidence of primary tumor formation, significant reduction in tumor metastatic potential, and altered responsiveness to the cytokine, transforming growth factor beta. Here we discuss emerging concepts concerning nm23, such as its varied pattern of alteration/expression in tumor metastasis, its effect on tumorigenesis, and its possible biochemical functions.
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PMID:Tumor metastasis and nm23: current concepts. 191 Oct 39

Tumorigenesis and invasive capacity of tumor cells are affected by the interactions between the tumor cells and the host cells; in particular, they are regulated by growth factors released from host cells. We have studied the effect of growth factors and cytokine on tumorigenesis and invasive capacity of tumor cells by examining a regressor tumor cell line (ER-1) derived from SHR rat mammary adenocarcinoma. The regressor tumor cells grew progressively in immunosuppressed rats, but spontaneously regressed in normal rats. We studied in vitro effect of growth factors on invasive capacity of ER-1 tumor cells into mesothelial cells obtained from SHR rats. As the results, pretreatment with EGF or TGF-beta significantly enhanced invasive capacity of ER-1 cells, whereas TNF-alpha did not show any effect. We pretreated ER-1 cells with EGF or TGF-beta for 24 hours in vitro, and then intraperitoneally transplanted them into SHR rats. The treated regressor tumor cells grew and killed the host. These results suggest that tumorigenesis and invasive capacity of regressor tumor cells are mediated by growth factors which promote growth and invasive abilities of tumor cells.
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PMID:[Enhancement of tumorigenesis and invasive capacity of regressor tumor cell by growth factors]. 195 44


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