Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001511 (Adhesion)
 5,955 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tumor necrosis factor-alpha (TNF-alpha) plays a role in several disease states such as sepsis, cachexia, and non-insulin-dependent diabetes. TNF-alpha interferes with insulin signaling and inhibits differentiation-specific gene expression in adipose tissue and skeletal muscle. We have examined the mechanisms by which TNF-alpha, in comparison to basic fibroblast growth factor (bFGF), inhibits the insulin-like growth factor-I (IGF-I)-induced differentiation of C2C12 myoblasts. Adhesion of quiescent, suspended myoblasts to collagen in high concentrations of IGF-I (10 nM) induced these cells to proliferate during the initial 24 h postplating and in so doing transiently inhibited the expression of myogenin, an essential transcription factor controlling myoblast differentiation. Low doses of IGF-I (1 nM) were minimally mitogenic and enhanced muscle-specific gene expression. Quiescent myoblasts treated with bFGF in combination with IGF-I did not express myogenin, but expressed proliferating cell nuclear antigen and underwent DNA synthesis. In contrast, TNF-alpha in the presence or absence of 1 nM IGF-I, did not stimulate DNA synthesis in myoblasts. However, TNF-alpha inhibited myogenin mRNA and protein expression. Expression of the cyclin-dependent kinase inhibitor p21 correlated with myogenin expression and myoblast differentiation, but not with growth arrest. These results indicate that both TNF-alpha and bFGF inhibit myogenin expression but differentially influence myoblast proliferation.
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PMID:Tumor necrosis factor-alpha and basic fibroblast growth factor differentially inhibit the insulin-like growth factor-I induced expression of myogenin in C2C12 myoblasts. 1032 64

In colorectal cancers, the local cytokine network and the levels of nitric oxide (NO) and reactive oxygen species (ROS) are known to be closely related to cancer progression and metastasis, but the influence of the currently administered therapies on the cancer microenvironment is not completely understood. We analyzed the levels of reactive oxygen species (ROS), nitric oxide (NO), and cachexia-mediated cytokines (IL-1beta, IL-6, TNF-alpha) in cocultures of human colon carcinoma spheroids prepared with cells derived from tumors of different grades with human normal colon epithelial and myofibroblast cells and normal endothelial cells. We also analyzed the influence of standard chemotherapy with 5-fluorouracil (5-FU) and leucovorin (LV) combined with camptothecin (CPT-11) (IFL regimen with drug concentrations adjusted to in vitro conditions) on these parameters. The results indicated that adhesion of colon carcinoma spheroids to colon epithelium and myofibroblast monolayers induced O2- anion production but decreased NO levels compared to the sum of the radicals released by monocultures of the two types of cells. Coculture of colon carcinoma spheroids with endothelium was an exception to this rule, as only HT29 cells decreased NO production. In cocultures, anticancer drugs additionally, though only slightly and insignificantly, increased the production of the radicals compared to a nontreated coculture, but in monocultures, the drugs, and especially CPT-11, were ROS inducers and simultaneously NO production inhibitors. However, the levels of released ROS and NO were dependent on the stage of colon carcinoma that the cells were derived from. LS180 cells (grade B) grown in monocultures produced the lowest ROS levels but were the best producers of NO. Adhesion of tumor spheroids to normal cells influenced the microenvironmental cytokine network compared to monocultures, decreasing IL-1beta and TNF-alpha secretion but significantly enhancing L-6 levels. The addition of the drugs had no effect on IL-1beta levels but increased TNF-alpha production and lowered the amounts of IL-6. In conclusion, cytotoxic drugs may, dependent on the stage of tumor growth or the type of chemotherapy regimen administered, significantly influence the proinflammatory cytokine network and local ROS and NO levels. Moreover, in cocultures of tumor cells with normal epithelial, myofibroblast, and endothelial cells, ROS production seems to be involved in local cell injury, which was detected by confocal microscopy. On the other hand, high level of NO seems to facilitate tumor cell interactions with the endothelium and metastasis as NO production was the highest in a monoculture of HUVEC and remained at high levels in cocultures of colon cancer cells with HUVEC. Among the proinflammatory cytokines, only IL-6 seems to significantly influence colon carcinoma development and metastasis. Attenuation of IL-6 production after chemotherapy can be a useful prognostic factor of its effectiveness.
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PMID:The importance of release of proinflammatory cytokines, ROS, and NO in different stages of colon carcinoma growth and metastasis after treatment with cytotoxic drugs. 2052