UMLS:C0677930 - FACTA Search

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Query: UMLS:C0677930 (primary tumor)
20,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Production of immunosuppressive factors is one of the mechanisms by which tumors evade immunosurveillance. Soluble factors hampering dendritic cell (DC) development have recently been identified in culture supernatants derived from tumor cell lines. In this study, we investigated the presence of such factors in 24-h culture supernatants from freshly excised solid human tumors (colon, breast, renal cell carcinoma, and melanoma). While primary tumor-derived supernatant (TDSN) profoundly hampered the in vitro DC differentiation from CD14(+) plastic-adherent monocytes or CD34(+) precursors (based on morphology and CD1a/CD14 phenotype), the effects of tested tumor cell line-derived supernatants were minor. Cyclooxygenase (COX)-1- and COX-2-regulated prostanoids present in the primary TDSN were found to be solely responsible for the observed hampered differentiation of monocyte-derived DC (MoDC). In contrast, both prostanoids and IL-6 were found to contribute to the TDSN-induced inhibition of DC differentiation from CD34(+) precursor cells. While the addition of TDSN during differentiation interfered with the ability of CD34-derived DC to stimulate a primary allogeneic T cell response, it actually increased this ability of MoDC. These opposite effects were correlated to different effects of the TDSN on the expression levels of CD86 and HLA-DR on the DC from the different precursor origins. Although TDSN increased the T cell-stimulatory capacity of MoDC, TDSN inhibited the IL-12 production and increased the IL-10 production of MoDC, thus skewing them to a type-2 T cell-inducing phenotype. In conclusion, this study demonstrates that primary tumors negatively impact DC development and function through COX-1 and -2 regulated factors, whereas tumor-derived cell lines may lose this ability upon in vitro propagation.
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PMID:Prostanoids play a major role in the primary tumor-induced inhibition of dendritic cell differentiation. 1197 Sep 75

It is well known that about 70% of cancer cases are due to environmental, dietary, or lifestyle factors. Accordingly, these cases maybe avoided by appropriate modifications. In addition, active chemoprevention has become a major interventional approach following the epidemiological observation of a beneficial effect of nonsteroidal anti-inflammatory drugs (NSAIDs) in colon cancer prevention. This is chiefly due to the inhibition of the cyclooxygenase (COX) enzymes. The COX enzymatic system includes two isoenzymes, COX-1 and COX-2, that convert arachidonic acid to prostaglandins. COX-1 is constitutively expressed and synthesizes cytoprotective prostaglandins in the gastrointestinal tract. COX-2 is inducible by the oncogenes ras and scr and other cytokines; it is overexpressed in human cancer cells in which it stimulates cellular division and angiogenesis and inhibits apoptosis. NSAIDs restore apoptosis and decrease tumor mitogenesis and angiogenesis. Most cancer cells have been found to exhibit overexpression of COX-2. Epidemiological studies showed a lower risk of developing cancer of the colon, breast, esophagus, and stomach following the ingestion of NSAIDs. The use of NSAIDs in low dose was associated with a statistically significant decrease in the risk of adenomatous polyps and of overt colon cancer. The regressive effects of sulindac on foci of aberrant crypts in the colon (considered to be precursors of adenoma), and on adenocarcinoma of the colon, are of particular interest because this NSAID does not have an inhibitory effect on COX. This may support the view that the antineoplastic effect of NSAIDs may also be due to a mechanism other than COX-2 inhibition. In breast cancer, large cohort studies reported a 40 to 50% reduced risk of developing cancer, a smaller size of the primary tumor, and a reduction in the number of involved axillary lymph nodes. Similar findings have been reported in the esophagus and stomach, but not in gastric cardia adenocarcinoma. The recent development of selective COX-2 inhibitors resulted in better clinical tolerance than that associated with NSAIDs in general, with the absence of gastrointestinal side effects known to occur after the inhibition of COX-1. Encouraging results have been obtained with these new agents in familial adenomatous polyposis, colon, breast, and prostate cancer.
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PMID:Epidemiological and clinical aspects of nonsteroidal anti-inflammatory drugs and cancer risks. 1208 6

Smokeless tobacco usage is a growing public health concern in the United States. Epidemiological evidence shows a correlation between use of chewing tobacco, lesions of the oral cavity and the incidence of oral and other cancers. However, the molecular mechanism(s) underlying the oral cancer causation are yet unknown. The major constituents of tobacco are known to cause inflammation, DNA damage and cell death. We propose modulation of inflammatory mediators by smokeless tobacco as a novel mechanism for the development of oral cancer. Exposure of hamster cheek pouches to smokeless tobacco extract (STE) results in cleavage of the anti-inflammatory peptide from the anti-inflammatory protein annexin I. Annexin I is produced from cultured oral epithelial cells and its expression is modulated by STE. We further show that STE exposure of oral epithelial cells results in upregulation of the pro-inflammatory protein COX-2. COX-2 is also upregulated in immortalized human oral epithelial cells, human squamous cell carcinoma cells and in primary tumor tissues from head and neck cancer. In summary, we find that exposure to smokeless tobacco results in loss of the anti-inflammatory activity of annexin I and upregulation of the pro-inflammatory COX-2 in oral cells. The dual effect of these regulatory events leads the cells down the carcinogenic pathway.
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PMID:Modulation of annexin I and cyclooxygenase-2 in smokeless tobacco-induced inflammation and oral cancer. 1287 Jun 56

Pathological expression of human ErbB-2 protein, also known as HER-2, is common in many types of cancer. ErbB-2 is a member of the EGF receptor tyrosine kinase family and has been rigorously studied as a signaling molecule on the cell membrane. Here, we report that ErbB-2 is also expressed in the nucleus in cultured cells as well as primary tumor tissues. Nuclear ErbB-2 was found to associate with multiple genomic targets in vivo, including the cyclooxygenase enzyme COX-2 gene promoter. ErbB-2 forms a complex at a specific nucleotide sequence of the COX-2 promoter and is able to stimulate its transcription. This study demonstrates the presence of ErbB-2 in the nucleus and identifies the function of ErbB-2 as a transcriptional regulator.
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PMID:Binding at and transactivation of the COX-2 promoter by nuclear tyrosine kinase receptor ErbB-2. 1538 May 16

Cancer is a dynamic process that involves many complex factors, which may explain why a "magic bullet" cure for cancer has not been found. Death rates are still rising for many types of cancers, which possibly contributes to the increased interest in chemoprevention as an alternative approach to the control of cancer. This strategy for cancer control is based on the presumption that because cancer develops through a multi-step process, each step may be a prospective target for reversing or suppressing the process. Thus, the design and development of chemopreventive agents that act on specific and/or multiple molecular and cellular targets is gaining support as a rational approach to control cancer. Nutritional or dietary factors have attracted a great deal of interest because of their perceived ability to act as highly effective chemopreventive agents. They are professed as being generally safe and may have efficacy as chemopreventive agents by preventing or reversing premalignant lesions and/or reducing second primary tumor incidence. Many of these dietary compounds appear to act on multiple target signaling pathways. Some of the most interesting and well documented are resveratrol and components of tea, including EGCG, theaflavins and caffeine. This review will focus on recent work regarding three well-accepted cellular/molecular mechanisms that may at least partially explain the effectiveness of selected food factors, including those indicated above, as chemopreventive anti-promotion agents. These food compounds may act by: (1) inducing apoptosis in cancer cells; (2) inhibiting neoplastic transformation through the inhibition of AP-1 and/or NF-kappaB activation; and/or (3) suppressing COX-2 overexpression in cancer cells.
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PMID:Targeting signal transduction pathways by chemopreventive agents. 1547 50

Increased cyclooxygenase-2 expression has been reported to be a poor prognostic indicator in a number of cancers. In this study we investigated the relationship between COX-2 expression in squamous cell carcinoma of the esophagus and tumor characteristics and patient survival. The study group consisted of 90 men and 48 women who underwent esophagectomy for squamous cell carcinoma of the esophagus between October 1984 and May 1985. COX-2 expression was measured by immunohistochemistry in 138 primary cancers, 23 metastatic lymph nodes and 21 normal esophageal stumps. The relationship between the extent of staining for COX-2 and clinicopathological features and survival was determined. The extent of staining for COX-2 in both primary and metastatic cancers was higher than in normal squamous epithelia (P = 0.002 and P < 0.0001 respectively), and the grade of staining in the primary tumor correlated positively with the finding of lymph node metastases (P = 0.03). The 5-year survival rate in patients with less than 10% COX-2 positive cells was 47.5% compared to 23.2% in patients with more than 10% COX-2 positive cells (P = 0.0036). The relationship between survival and COX-2 staining was not due to COX-2 being a surrogate marker for TNM stage. Our results show that the expression of COX-2 is elevated in squamous cell carcinoma of the esophagus compared to normal epithelium and correlates with lymph node metastases. Survival was longer in those patients whose tumors expressed lower levels of COX-2.
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PMID:Cyclooxygenase-2 expression in squamous cell carcinoma of the esophagus. 1698 31

The ECRG4 gene was initially identified and cloned in our laboratory from human normal esophageal epithelium (GenBank accession no. AF325503). We revealed the expression of ECRG4 protein was downregulated in 68.5% (89/130) ESCC samples using tissue microarray. The low ECRG4 protein expression was significantly associated with regional lymph node metastasis, primary tumor size, and tumor stage in ESCC (p < 0.05). ECRG4 mRNA expression was downregulated in ESCC due to the hypermethylation in the gene promoter. The treatment with 5-aza-2'-deoxycytidine, which is a DNA methyltransferase inhibitor restored ECRG4 mRNA expression in ESCC cells. The result indicated that promoter hypermethylation may be 1 main mechanism leading to the silencing of ECRG4. The high expression of ECRG4 in patients with ESCC was associated with longer survival compared with those with low ECRG4 expression by Kaplan-Meier survival analysis (p < 0.05). ECRG4 protein was an independent prognostic factor for ESCC by multivariable Cox proportional hazards regression analysis (p < 0.05). The restoration of ECRG4 expression in ESCC cells inhibited cell proliferation, colony formation, anchorage-independent growth, cell cycle progression and tumor growth in vivo (p < 0.05). The transfection of ECRG4 gene in ESCC cells inhibited the expression of NF-kappaB and nuclear translocation, in addition to the expression of COX-2, a NF-kappaB target gene, was attenuated. Taken together, ECRG4 is a novel candidate tumor suppressor gene in ESCC, and ECRG4 protein is a candidate prognostic marker for ESCC.
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PMID:Expression of esophageal cancer related gene 4 (ECRG4), a novel tumor suppressor gene, in esophageal cancer and its inhibitory effect on the tumor growth in vitro and in vivo. 1952 89

Cyclooxygenase (COX)-derived prostaglandin E(2) (PGE(2)) plays a role in the development and progression of several tumor types including head and neck squamous cell carcinoma (HNSCC). Measurements of urinary PGE metabolite (PGE-M) can be used as an index of systemic PGE(2) production. In ever smokers, increased levels of urinary PGE-M reflect increased COX-2 activity. In this study, we determined whether baseline levels of urinary PGE-M were prognostic for ever smoker HNSCC patients. A retrospective chart review of ever smoker HNSCC patients treated with curative intent was done. Fifteen of 31 evaluable patients developed progressive disease (recurrence or a second primary tumor) after a median follow-up of 38 months. There were no statistically significant differences between patients with (n = 15) or without disease progression (n = 16) with regard to stage, site, treatment received, smoking status, and aspirin use during follow-up. Median urinary PGE-M levels were significantly higher in HNSCC patients with disease progression (21.7 ng/mg creatinine) compared with patients without (13.35 ng/mg creatinine; P = 0.03). Importantly, patients with high baseline levels of urinary PGE-M had a significantly greater risk of disease progression (hazard ratio, 4.76, 95% CI, 1.31-17.30; P < 0.01) and death (hazard ratio, 9.54; 95% CI, 1.17-77.7; P = 0.01) than patients with low baseline levels of urinary PGE-M. These differences were most evident among patients with early-stage disease. Taken together, our findings suggest that high baseline levels of urinary PGE-M indicate a poor prognosis in HNSCC patients. Possibly, HNSCC patients with high COX-2 activity manifested by elevated urinary PGE-M will benefit from treatment with a COX-2 inhibitor.
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PMID:Elevated levels of urinary prostaglandin e metabolite indicate a poor prognosis in ever smoker head and neck squamous cell carcinoma patients. 1984 89

Malignant peripheral nerve sheath tumor (MPNST) is a rare soft tissue sarcoma. We established a new human MPNST cell line (designated FMS-1) from MPNST of the right brachial plexus of a 69-year-old woman with NF1. The cell line has been maintained for >24 months with >100 passages. FMS-1 cells showed a fibrosarcoma-like or epithelioid pattern in the heterotransplanted tumor, compared with a fascicular growth pattern of short-spindle tumor cells in the primary tumor. Immunophenotypically, FMS-1 cells showed almost the same characteristics as the primary tumor. Cytogenetic and molecular analyses revealed a deletion in exons 5-8 of the p53 gene. Epidermal growth factor receptor (EGFR) and cyclooxygenase (COX)-2 were expressed in FMS-1 cells. To improve the highly aggressive course and poor prognosis and establish new therapeutic methods, molecular genetic and biological characterizations of MPNST are required. Thus, FMS-1 cells might be useful for investigating biological behaviors and developing new molecular-targeting antitumor drugs for MPNST expressing EGFR or COX-2.
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PMID:Establishment and characterization of a novel human malignant peripheral nerve sheath tumor cell line, FMS-1, that overexpresses epidermal growth factor receptor and cyclooxygenase-2. 1992 Dec 53

Prostaglandins support progression of colorectal cancer by several mechanisms. This conclusion is based on epidemiological and drug intervention long-term studies or retrieved from animal and cell culture experiments. The aim of the present study was to map receptor and enzyme expression for prostanoid metabolism in the presence of high or low PGE2 content within colon cancer tissue at primary tumor operation and after short-term preoperative provision of non-steroidal anti-inflammatory drug (NSAID). Twenty-three unselected patients with colon cancer were randomly selected to receive indomethacin (NSAID) or sham treatment for 3 days before surgery. Normal colon and tumor tissue were collected at operation for RNA extraction. Tissue PGE2 levels were measured by radioimmunoassay. Gene expression was quantified by microarray and real-time PCR. COX-1 expression increased proportionally to COX-2 expression in colon cancer tissue from untreated patients. Indomethacin reduced PGE2 content in normal and tumor tissue with subsequently decreased IP, HPGD and PPARgamma receptor expression in both tumor and normal colon tissue, while subtype EP1-4 receptors were not significantly influenced by indomethacin treatment. MPGES-1 expression was not related to overall PGE2 content in tumor and colon tissue, but decreased significantly in normal tissue during indomethacin exposure. Reduction of tumor tissue PGE2 was related to significant alteration in expression of several hundred genes indicating decreased cell cycling and increased apoptosis during indomethacin treatment, probably related to upregulation of acute phase reactants in tumor tissue. Increased prostanoid activity in colon cancer tissue is related to cross-talk between tumor and stroma cells.
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PMID:Receptor and enzyme expression for prostanoid metabolism in colorectal cancer related to tumor tissue PGE2. 2004 83

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