Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0677930 (primary tumor)
 20,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The process of cancer metastasis consists of multiple sequential and highly selective steps. The vast majority of tumor cells that enter the circulation die rapidly and only a few survive and proliferate to form distant metastases. This survival is not random. Metastases are clonal in origin and are produced by specialized subpopulations of cells that preexist in a heterogeneous primary tumor. Metastatic cells of the murine K-1735 melanoma survive in the circulation to produce experimental lung metastases, whereas nonmetastatic cells do not. After incubation with different cytokines or LPS, nonmetastatic cells exhibit a high level of inducible nitric oxide synthase (iNOS) activity and nitric oxide (NO) production, whereas metastatic cells do not. To provide direct evidence for the inverse correlation between the production of endogenous NO and the ability of K-1735 cells to produce metastasis in syngeneic mice, highly metastatic clone 4 cells (C4.P), which express low levels of iNOS, were transfected with a functional iNOS (C4.L8), inactive mutated iNOS (C4.S2), or neomycin resistance (C4.Neo) genes in medium containing 3 mM NMA. C4.P, C4.Neo3, and C4.S2.3 cells were highly metastatic, whereas C4.L8.5 cells were not. Moreover, C4.L8.5 cells produced slow-growing subcutaneous tumors in nude mice, whereas the other three cell lines produced fast-growing tumors. In vitro studies indicated that the expression of iNOS in C4.L8.5 cells was associated with apoptosis. Multiple intravenous injections of liposomes containing a synthetic lipopeptide upregulated iNOS expression in murine M5076 reticulum sarcoma cells growing as hepatic metastases. The induction of iNOS was associated with the complete regression of the lesions. Collectively, these data demonstrate that the expression of iNOS in tumor cells is associated with apoptosis, suppression of tumorigenicity, abrogation of metastasis, and regression of established hepatic metastases.
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PMID:Activation of nitric oxide synthase gene for inhibition of cancer metastasis. 869 Oct 63

To identify genes associated with tumor metastasis, we prepared 5 cDNA libraries using mRNA from normal ovaries, paired primary and metastatic ovarian tumors, as well as paired cultured ovarian tumor cells. By differential screening, we identified 12 clones, which can be divided into 3 classes based on hybridization to various probes. Class 1 clones showed no reaction with the normal probe, slight or no reaction with the primary probe, but high reaction with the metastatic probe. Class 2 clones showed some reaction with normal and primary probes, but showed stronger reaction with the metastatic probe. Class 3 clones showed strong hybridization to the normal probe, slight or no reaction with the primary probe, and did not hybridize with the metastatic clone. These clones were further analyzed by determination of DNA sequence. One of the class 1 clones (clone 1) was identified as ferritin heavy chain. Northern blot analysis showed higher expression of ferritin H-chain in metastatic samples compared to primary tumor in 16/23 pairs of samples analyzed so far.
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PMID:Elevated expression of ferritin H-chain mRNA in metastatic ovarian tumor. 895 66

The process of cancer metastasis consists of multiple sequential and highly selective steps. The vast majority of tumor cells that enter the circulation die rapidly; only a few survive to produce metastases. This survival is not random. Metastases are clonal in origin and are produced by specialized subpopulations of cells that preexist in a heterogeneous primary tumor. Experimental studies concluded that metastatic cells survive in the circulation whereas nonmetastatic cells do not. In part, this difference is due to an inverse correlation between expression of endogenous inducible nitric oxide synthase (iNOS) and production of nitric oxide (NO) and metastatic potential. Direct evidence for the role of iNOS in metastasis has been provided by our data on transfection of highly metastatic murine K-1735 clone 4 (C4.P) cells which express low levels of iNOS, with a functional iNOS (C4.L8), inactive mutated iNOS (C4.S2), or neomycin resistance (C4.Neo) genes in medium containing 3 mM of the specific iNOS inhibitor NG-L-methyl arginine (NMA). C4.P, C4.Neo, and C4.S2 cells were highly metastatic, whereas C4.L8 cells were not. Moreover, C4.L8 cells produced slow-growing subcutaneous tumors in nude mice, whereas the other 3 cell lines produced fast-growing tumors. In vitro studies indicated that the expression of iNOS in C4.L8.5 cells was associated with either cytostasis or cytolysis via apoptosis, depending upon NO output. The tumor cells producing high levels of NO underwent autocytolysis and produced cytolysis of bystander cells under both in vitro and in vivo conditions. Multiple i.v. injections of liposomes containing a synthetic lipopeptide upregulated iNOS expression in murine M5076 reticulum sarcoma cells growing as hepatic metastases. The induction of iNOS was associated with the complete regression of the lesions. Transfection of interferon-beta suppressed tumor formation and eradicated metastases, which was apparently linked to iNOS expression and NO production in host cells such as macrophage. Besides mediating cell death, NO produced tumor suppression by regulating expression of genes related to metastasis, e.g., survival, invasion, and angiogenesis. Suppression of metastasis can be achieved through use of immunomodulators that induce iNOS expression in tumor lesions or by the direct delivery of the iNOS gene to tumor cells or host cells through liposome and/or viral vectors.
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PMID:Therapy of cancer metastasis by activation of the inducible nitric oxide synthase. 954 23

A nonhydrolyzable ether analogue of RRR-alpha-tocopherol, 2,5,7,8-tetramethyl-2R-(4R, 8R, 12-trimethyltridecyl)chroman-6-yloxyacetic acid, called RRR-alpha-tocopheryloxyacetic acid or RRR-alpha-tocopherol ether-linked acetic acid analogue (alpha-TEA), exhibits antitumor activity in vitro and in vivo using a syngeneic BALB/c mouse mammary tumor model (line 66 clone 4 stably transfected with green fluorescent protein). Treatment of cells with 5, 10, and 20 micro g/ml alpha-TEA for 3 days produced 6, 34, and 50% apoptosis, respectively, and treatment of cells with 10 micro g/ml for 2, 3, 4, and 5 days produced 20, 35, 47, and 58% apoptosis, respectively. A liposomal formulation of alpha-TEA administered by aerosol reduced s.c. tumor growth and lung metastasis. Alpha-TEA-treated animals showed a significant decrease in tumor volumes over 17 days of aerosol treatment (P < 0.001). Forty percent of aerosol as well as untreated control mice had visible, macroscopic lung metastases versus none (0%) of the alpha-TEA-treated mice. On the basis of fluorescence microscopic examination of the surface (top and bottom) of flattened whole left lung lobes, an average of 60 +/- 15 and 102 +/- 17 versus 11 +/- 4 fluorescent microscopic metastases was observed in aerosol control and untreated control versus alpha-TEA-treated animals, respectively. Alpha-TEA formulated in ethanol + peanut oil (5 mg/mouse/day) delivered by gavage did not reduce s.c. primary tumor burden; however, fluorescent microscopic lung metastases were significantly reduced (P < 0.0021). In summary, alpha-TEA formulated in liposomes and delivered by aerosol is a potent antitumor agent and reduces lung metastasis.
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PMID:Novel vitamin E analogue decreases syngeneic mouse mammary tumor burden and reduces lung metastasis. 1274 5