Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It is well accepted that an increase in the expression of cyclooxygenase-2 (COX-2), a key inducible enzyme involved in the production of prostaglandins and other eicosanoids, may play a significant role in carcinogenesis in addition to its well-known role in inflammatory reactions. Whereas previous studies were largely confined to colorectal tumorigenesis, we have shown that a significantly increased expression of COX-2 may also play a role in the development of lung cancer. COX-2 expression was found to be frequently elevated in lung cancer, especially in adenocarcinoma, and the proportion of lung cancer cells with marked COX-2 expression was much higher in lymph node metastases than in the corresponding primary tumors. It was also shown that early stage adenocarcinoma patients with increased COX-2 expression who were surgically treated had a shorter survival. Our studies, which used high- and low-metastatic human lung cancer cell sublines established in our laboratory, revealed an association between metastatic capabilities and COX-2 expression levels: COX-2-specific inhibitors could inhibit in vitro the invasion of the highly metastatic NCI-H460-LNM35 clone through Matrigel-containing basement membrane components as well as the spontaneous in vivo metastasis in SCID mice. Taken together, these findings suggest that an increase in COX-2 expression maybe associated with the development of lung cancer and possibly with the acquisition of an invasive and metastatic phenotype.
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PMID:Increased expression of COX-2 in the development of human lung cancers. 1208 4

Nasopharyngeal carcinoma (NPC) is a malignant tumor associated with Epstein-Barr virus (EBV). Latent membrane protein-1 (LMP-1) is an EBV-encoded oncoprotein and is detected in approximately 50-70% of patients with NPC. LMP-1 is thought to play an essential role in tumorigenesis of NPC. In addition to its transforming properties, LMP-1 has been suggested to be associated with promotion of metastasis. Metastasis is a phenomenon composed of multiple sequential cascades. Reduction of tumor cell adhesion, degradation of extracellular matrix, basement membrane, enhancement of cell motility, and promotion of neovascularization are thought to be essential steps. LMP-1 down-regulates expression of E-cadherin, induces matrix metalloproteinase-9 and urokinase type-plasminogen activator through activation of NF-kappaB and AP-1, and enhances cell motility via ets-1 activation. LMP-1 also induces vascular endothelial growth factor through cyclooxygenase-2 activation and interleukin-8 through NF-kappaB activation. Clinical studies suggested the association of these factors with metastatic status of patients with NPC. In this review, the role of LMP-1 in the metastasis of NPC is discussed.
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PMID:Promotion of metastasis in nasopharyngeal carcinoma by Epstein-Barr virus latent membrane protein-1. 1216 95

Cyclooxygenase-2 (COX-2), an enzyme that catalyzes the synthesis of prostaglandins, is overexpressed in a variety of premalignant and malignant conditions, including oral leukoplakia and squamous cell carcinoma of the head and neck. Increased levels of COX-2 may contribute to carcinogenesis by modulating xenobiotic metabolism, apoptosis, immune surveillance, and angiogenesis. In experimental models, newly developed selective COX-2 inhibitors suppress the formation of tumors, including tongue cancer. These findings provided a rationale for a number of chemoprevention trials that are underway. Selective COX-2 inhibitors also suppress the growth and metastases of established tumors and enhance the anticancer activity of both radiotherapy and chemotherapy in experimental animals. In this review, evidence is presented that inhibition of COX-2 represents a promising strategy to prevent or possibly treat human head and neck cancers.
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PMID:Cyclooxygenase-2: a novel molecular target for the prevention and treatment of head and neck cancer. 1220 6

The results of animal studies have demonstrated that the consumption of omega-3 fatty acids can slow the growth of cancer xenografts, increase the efficacy of chemotherapy and reduce the side effects of the chemotherapy or of the cancer. Molecular mechanisms postulated to contribute to the multiple benefits of omega-3 fatty acids include 1) suppressing the expression of cyclooxygenase-2 in tumors, thus decreasing proliferation of cancer cells and reducing angiogenesis in the tumor; 2) decreasing the expression of AP-1 and ras, two oncogenes implicated in tumor promotion; 3) inducing differentiation of cancer cells; 4) suppressing nuclear factor-kappaB activation and bcl-2 expression, thus allowing apoptosis of cancer cells; and 5) reducing cancer-induced cachexia. It seems reasonable to assume that after appropriate cancer therapy, consumption of omega-3 fatty acids might slow or stop the growth of metastatic cancer cells, increase longevity of cancer patients and improve their quality of life.
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PMID:Omega-3 fatty acids to augment cancer therapy. 1242 78

Selective inhibition of eicosanoid synthesis is thought to have effects on carcinogenesis in lung and colon cancer. However, it is still unknown whether pancreatic cancer might also be influenced. Therefore we evaluated the impact of selective cyclooxygenase-2 inhibitor Celebrex and selective 5-lipoxygenase inhibitor Zyflo on liver metastasis in a solid model of pancreatic adenocarcinoma in Syrian hamster. In week 33, the animals were sacrificed and incidence of pancreatic carcinomas and number and size of liver metastases were determined. Activities of antioxidative enzymes (GSHPX/SOD) and concentrations of products of lipidperoxidation were measured in liver metastases and non-metastatic hepatic tissue. The incidence (54.5 vs. 100%), number (3.17 +/- 0.98 vs. 6.75 +/- 0.71) and size (2.67 +/- 1.97 vs. 11.75 +/- 1.98 mm2) of liver metastases were decreased by combined therapy of Zyflo and Celebrex (P < 0.05). Furthermore, activities of GSHPX ([73.77 +/- 5.67]*10(5) vs. [15.49 +/- 4.02]*10(5) U/mg prot.; P < 0.05) and SOD (474.92 +/- 108.8 vs. 127.89 +/- 38.75 U/mg prot.; P < 0.05) were increased, while lipidperoxidation (0.31 +/- 0.08 nmol/mg prot. vs. 1.54 +/- 0.55 nmol/mg prot.; P < 0.05) was decreased by combination therapy, in non-metastatic hepatic tissue. Moreover, combined therapy increased lipidperoxidation in liver metastases (0.47 +/- 0.09 vs. 1.95 +/- 0.12 nmol/mg prot.; P < 0.05). Thus, a combination of Celebrex and Zyflo might be a new concept to decrease tumour growth in liver metastases in advanced pancreatic cancer.
Clin Exp Metastasis 2002
PMID:Effects of Celebrex and Zyflo on liver metastasis and lipidperoxidation in pancreatic cancer in Syrian hamsters. 1255 73

Cyclooxygenase-2 (COX-2) is over expressed in a variety of premalignant and malignant conditions. It may contribute to carcinogenesis by modulating xenobiotic metabolism, apoptosis, immune surveillance, and angiogenesis. Selective COX-2 inhibitors suppress the formation of tumors in experimental models. Selective COX-2 inhibitors also suppress the growth and metastases of established tumors and enhance the anticancer activity of both radiotherapy and chemotherapy in experimental animals. This review aims at discussing evidence that inhibition of COX-2 represents a promising strategy to treat, prevent or possibly prevent human malignancies. Importantly, selective COX-2 inhibitors do not inhibit platelet function and cause fewer gastrointestinal side effects (peptic ulcer disease) than traditional nonsteroidal anti-inflammatory drugs (NSAIDS). More clinical trials are warranted to define the role of selective COX-2 inhibitors in the prevention and treatment of cancer along with their assessment of toxicity.
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PMID:Role of COX-2 specific inhibitors in oncogenesis. 1281 42

In order to develop new therapeutic regimens for biliary tract cancers, which carry dismal prognoses, the establishment of a human biliary tract cancer xenograft model is essential. Herein, we report the successful establishment and characterization of two xenograft models of human biliary tract cancers. An adenosquamous gallbladder cancer cell line (TGBC-44) and a bile duct adenocarcinoma cell line (TGBC-47) were obtained from fresh surgical specimens in our department and subcutaneously inoculated into nude mice. The overall tumor take rate was 100% and solid tumors grew measurable after 5 and 7 days for TGBC-44 and TGBC-47, respectively. Tumor doubling time was 3.9+/-1.1 and 4.1+/-0.5 days in the exponential growth phase in TGBC-44 and TGBC-47 xenografts, respectively. Isozyme test and karyotype analysis confirmed the human origin. Histopathology analysis revealed that the TGBC-44 xenograft retained both the squamous and the adenocarcinoma components, and the TGBC-47 xenograft exhibited poorly differentiated adenocarcinoma as in the corresponding original tumors. Immunohistochemistry and Western blotting studies revealed positive and similar expression of platelet derived endothelial growth factor/thymidine phosphorylase (PDGF/TP), thymidylate synthase (TS), and cyclooxygenase-2 (COX-2) in both original tumors and xenograft models. No macroscopic metastases were found at the time of sacrifice. We have successfully established two models of human biliary tract cancer, gallbladder and bile duct cancer. Models retained the morphological and biochemical characteristics of the original tumor and demonstrated constant biological behavior in all transplanted mice. These models could be useful tools for developing new diagnostic and therapeutic strategies against biliary tract cancers.
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PMID:Establishment and characterization of novel xenograft models of human biliary tract carcinomas. 1453 68

Medullary thyroid cancer (MTC) is a C cell neoplasm-secreting calcitonin. Surgery remains the only treatment as the primary tumor and metastases resist radio- and chemotherapies. MTC produces high amounts of prostaglandins (PGs). Nonsteroidal antiinflammatory drugs have an antitumoral effect, generally related to the decrease of PG levels. We assessed the therapeutic potential of indomethacin in a model of human (TT cells) tumors in nude mice. Indomethacin (1.5 or 2.0 mg/kg body weight.d for 7 wk) inhibited tumor volume by 49 or 77%, respectively, and decreased the plasma level of CT. Although the terminal deoxynucleotidyltransferase-mediated deoxyuridine triphosphate nick end labeling method revealed few apoptotic nuclei, the number of proliferating cells was significantly decreased (Ki-67 antigen study). Immunological effector recruitment and vascular network was not modified by treatment. The inducible synthesis enzyme, cyclooxygenase-2 (COX-2), was revealed only in infiltrating cells, both in treated and control tumors. The expression of the constitutive synthesis enzyme COX-1 was diminished, and the expression of 15-prostaglandin dehydrogenase, the key enzyme catabolizing PGs, was increased in treated tumors. Thus, our results demonstrated the potential of indomethacin, inhibitor of COX-1 and COX-2, to prevent MTC growth. The synthesis enzyme, COX-1, and the catabolism enzyme 15-prostaglandin dehydrogenase, could be involved in MTC development.
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PMID:Tumor growth inhibition by indomethacin in a mouse model of human medullary thyroid cancer: implication of cyclooxygenases and 15-hydroxyprostaglandin dehydrogenase. 1473 30

Cyclooxygenase-2 (COX-2) is an inducible enzyme that regulates prostaglandin synthesis and is overexpressed at sites of inflammation and in several epithelial cancers. Recently, a causal link for COX-2 in epithelial tumorigenesis was shown in genetically-manipulated animal models of colon and breast carcinoma. Data indicate that COX-2 is involved in the regulation of apoptosis, angiogenesis, and tumor cell invasiveness, which appear to contribute to its effects on tumorigenesis. Multiple studies have shown that nonselective COX and selective COX-2 inhibitors effectively prevent experimental colon cancer. Furthermore, sulindac and the selective COX-2 inhibitor celecoxib were shown to regress colorectal polyps in patients with familial adenomatous polyposis. Although the exact anti-tumor mechanisms of these agents await further study, data indicate that both COX-dependent and COX-independent mechanisms may be important. In this review, the association between COX-2 and colorectal tumorigenesis and potential mechanisms of this effect are discussed. Additionally, evidence supporting the role of NSAIDs and selective COX-2 inhibitors for the prevention and treatment of human colorectal cancer is reviewed.
Cancer Metastasis Rev
PMID:Role of cyclooxygenase-2 in colorectal cancer. 1500 Jan 50

Cyclooxygenase-2 (COX-2) has been identified as a potential target for prevention and therapy of human colorectal cancers (CRC) and other cancers. Because right-sided colon cancers (RSCCs) exhibit clinicopathologic and genetic differences from left-sided colorectal cancers (LSCRCs), determination of COX-2 status in these subsets of CRCs may be clinically relevant in designing COX-2 inhibitor trials for CRC and in subsequent assessment of objective therapeutic response to such therapy. Thirty-six primary CRC resection specimens (18 left, 18 right) from 36 patients were evaluated. Representative tumor sections were subjected to immunohistochemical analysis of COX-2. A semiquantitative system was used to score cytoplasmic COX-2 immunostaining. The tumors were considered COX-2 positive if more than 10% tumor cells showed COX-2 staining. Clinicopathologic and COX-2 data were compared for LSCRCs versus RSCCs. All 18 LSCRCs and 13 of 18 (72%) RSCCs were well to moderately differentiated. Overall rates of COX-2 positivity for the LSCRCs versus RSCCs were 67% (12 of 18) and 33% (6 of 18), respectively (P = 0.04). Furthermore, 11 of 12 (92%) COX-2 positive LSCRCs and 3 of 6 (50%) COX-2 positive RSCCs were stage II-IV at resection. All 12 COX-2 positive LSCRCs were associated with advanced primary tumor and 4 of 12 (33%) LCRCs had distant metastases. These associations could not be evaluated for the RSCCs because of the limited number of COX-2 positive cases. The more frequent expression of COX-2 in LSCRCs as compared with RSCCs supports the hypothesis that COX-2 expression may be related to genetic alterations specific to right- or left-sided CRCs. Further studies are needed to elucidate such relationships. Our data also suggest that stratification of patients with CRC into right- and left-sided subsets may be important in optimal patient selection for COX-2 inhibitor therapy and for subsequent assessment of objective therapeutic response.
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PMID:Cyclooxygenase-2 expression in right- and left-sided colon cancer: a rationale for optimization of cyclooxygenase-2 inhibitor therapy. 1502 97


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