Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1519670 (tumor angiogenesis)
 6,052 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Inducible nitric oxide (NO) synthase (iNOS) appears to be a marker of tumor progression in colon carcinogenesis. Here we investigated effects of NO on selected chemokines that differentially regulate angiogenesis, namely pro-angiogenic interleukin (IL)-8 as well as tumor-suppressive interferon-inducible protein-10 (IP-10) and monokine induced by interferon-gamma (MIG). These chemokines are expressed by DLD-1 colon carcinoma cells after stimulation with IL-1beta/interferon-gamma. Expression of IL-8 was markedly upregulated by NO. Moreover, NO enhanced expression of vascular endothelial growth factor (VEGF). In contrast, expression of IP-10 and MIG was suppressed by NO. The present data are consistent with previous observations that link NO to enhanced tumor angiogenesis and imply that NO-mediated upregulation of IL-8 and VEGF as well as downregulation of IP-10 and MIG may contribute to this phenomenon.
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PMID:Nitric oxide differentially regulates pro- and anti-angiogenic markers in DLD-1 colon carcinoma cells. 1506 30

A replication-defective adenoviral vector, Ad.Egr-TNF.11D, was engineered by ligating the CArG (CC(A/T)6GG) elements of the Egr-1 gene promoter upstream to a cDNA encoding human tumor necrosis factor-alpha. We report here that Ad.Egr-TNF.11D is activated by the clinically important anticancer agents cisplatin, cyclophosphamide, doxorubicin, 5-fluorouracil, gemcitabine, and paclitaxel. N-acetylcysteine, a free radical scavenger, blocked induction of tumor necrosis factor-alpha by anticancer agents, supporting a role for reactive oxygen intermediates in activation of the CArG sequences. Importantly, resistance of PC-3 human prostate carcinoma and PROb rat colon carcinoma tumors to doxorubicin in vivo was reversed by combining doxorubicin with Ad.Egr-TNF and resulted in significant antitumor effects. Treatment with Ad.Egr-TNF.11D has been associated with inhibition of tumor angiogenesis. In this context, a significant decrease in tumor microvessel density was observed following combined treatment with doxorubicin and Ad.Egr-TNF.11D as compared with either agent alone. These data show that Ad.Egr-TNF.11D is activated by diverse anticancer drugs.
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PMID:Chemoinducible gene therapy: a strategy to enhance doxorubicin antitumor activity. 1536 11

Progression of tumors to invasive and metastatic forms requires that tumor cells undergo dramatic morphologic changes, a process regulated by Rho GTPases. Elevated expression of RhoA and RhoC, as well as the Rho effector proteins ROCK I and ROCK II, are commonly observed in human cancers and are often associated with more invasive and metastatic phenotypes. To examine how ROCK contributes to the progression of solid tumors, we established a conditionally activated form of ROCK II by fusing the kinase domain to the estrogen receptor hormone-binding domain (ROCK:ER). ROCK:ER-expressing colon carcinoma cells grown as tumors in immunocompromised nude mice organized into discrete clusters surrounding blood vessels. However, ROCK:ER activation resulted in the aggressive dissemination of tumor cells into the surrounding stroma, indicating that increased ROCK signaling is sufficient to promote invasion from solid tumors. In addition, tumors in which ROCK:ER was activated were more highly vascularized, indicating that ROCK contributes to tumor angiogenesis. ROCK:ER activation resulted in changes to epithelial morphology and organization that facilitated motility in vitro, likely by inducing the redistribution of proteins such as ezrin, as well as adherens junction and extracellular matrix-binding proteins. These results suggest that ROCK inhibitors would be useful antimetastatic and antiangiogenic chemotherapeutic agents in tumors associated with elevated RhoA, RhoC, ROCK I, or ROCK II expression.
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PMID:Conditional ROCK activation in vivo induces tumor cell dissemination and angiogenesis. 1560 64

Inhibition of tumor angiogenesis is a promising approach for cancer therapy. As an endothelial cell-specific receptor kinase expressed almost exclusively on the surface of vascular endothelium, Tie-2 has an important role in tumor angiogenesis. To explore the therapeutic potential of blocking Tie-2 receptor-interaction pathway, an adenoviral vector was used to deliver a recombinant single-chain antibody fragment rabbit intrabody (pAd-2S03) capable of inhibition of both mouse and human Tie-2 surface expression. pAd-2S03 was given to mice with well-established primary tumors, either a human Kaposi's sarcoma (SLK) or a human colon carcinoma (SW1222). The intrabody significantly inhibited growth of both tumors (75% and 63%, respectively) when compared with pAd-GFP control-treated tumors (P < 0.01). Histopathologic analysis of cryosections taken from mice treated with pAd-2S03 revealed a marked decrease in vessel density, which was reduced by >87% in both tumor models when compared with control-treated tumors (P < 0.01). In contrast, human Tie-2-monospecific pAd-1S05 intrabody did not affect the growth of tumors, indicating that the antitumor effect of pAd-2S03 was due to the inhibition of tumor angiogenesis in these murine models. Our results show that the Tie-2 receptor pathway is essential for both SLK sarcoma and SW1222 colon carcinoma xenograft growth. The present study shows the potential utility of antiangiogenic agents that target the endothelium-specific receptor Tie-2 for down-regulation or genetic deletion.
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PMID:Targeting tumor angiogenesis with adenovirus-delivered anti-Tie-2 intrabody. 1570 98

It is well established that hypoxia potently stimulates tumor angiogenesis by activating hypoxia inducible factor-1 (HIF-1)-induced proangiogenic factors, such as vascular endothelial growth factor. However, very little is known about the role of hypoxia in incipient angiogenesis in avascular tumors during their early stages of growth. To noninvasively investigate the functional significance of hypoxia and HIF-1 activation in incipient tumor angiogenesis, we genetically engineered HCT116 human colon carcinoma cells and 4T1 mouse mammary carcinoma cells with constitutively expressed red fluorescence protein as a tumor marker and green fluorescence protein (GFP) as a reporter for hypoxia and HIF-1 activation. The accuracy of GFP fluorescence in reporting hypoxia was confirmed by flow cytometry analysis and by immunohistochemical comparison with pimonidazole, a well-established hypoxia marker drug. Mouse dorsal skin-fold window chambers showed that incipient angiogenesis preceded a detectable level of hypoxia. The detectable levels of hypoxia were spatially and temporally related with more intensive secondary angiogenesis following the initial onset of new vessel formation. Selective killing of hypoxic cells by tirapazamine efficiently eliminated or delayed the detection of hypoxic cells, but it did not significantly delay the onset of incipient angiogenesis. These findings provide the first in vivo evidence that incipient tumor angiogenesis may not depend on hypoxia or HIF-1 activation. This is in contrast to the clear role of hypoxia in driving angiogenesis once initial tumor microvessel formation has occurred.
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PMID:Observation of incipient tumor angiogenesis that is independent of hypoxia and hypoxia inducible factor-1 activation. 1599 19

Targeting tumor endothelium is an important strategy for cancer therapy. We evaluated the effectiveness of gene therapy, that is, intramuscular delivery of plasmid DNA encoding tumstatin (pSecTag2B-tum), combined with gemcitabine administration in vitro and in vivo, using colon carcinoma (CT26) and Lewis lung carcinoma (LLC) murine models. The in vitro growth-inhibitory and proapoptotic effects of gemcitabine and/or tumstatin on human umbilical vein endothelial cells (HUVECs) and mouse endothelial cells (SVEC4-10), respectively, were assessed. in vitro, conditioned medium from pSecTag2B-tum-transfected COS cells inhibited the growth of endothelial cells but not of CT26 or LLC cells, whereas gemcitabine inhibited the growth of both endothelial cells and CT26 and LLC cells. Mice bearing subcutaneously established CT26 or LLC tumors received pSecTag2B-tum alone or in combination with gemcitabine to assess tumor growth inhibition. in vivo, combined treatment with pSecTag2B-tum and gemcitabine significantly decreased tumor growth through increased inhibition of tumor angiogenesis and increased tumor cell apoptosis compared with either agent alone. Enhanced antiproliferative and proapoptotic activity of the combination therapy on tumor-associated endothelial cells was calculated to be significant. This study suggests that combined treatment by the intramuscular delivery of plasmid DNA encoding tumstatin and gemcitabine augments tumor growth inhibition by suppressing angiogenesis and enhancing apoptosis in murine models. A combination of these agents could be used in future studies and translated into the clinical setting.
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PMID:Enhanced antitumor effect of the combination of tumstatin gene therapy and gemcitabine in murine models. 1614 6

The immunization approaches with DNA vaccine priming and subsequent protein or peptide boosting has been widely tested in various models of infectious diseases. However, these approaches are seldom reported in the areas of cancer immunotherapy. In this study we combined endoglin plasmid DNA and recombinant protein as vaccines and used them to prime and boost, simultaneously, as a vaccine strategy. Our results showed that combination of endoglin DNA and protein vaccines could enhance both protective and therapeutic anti-tumor efficacy in both colon carcinoma and Lewis lung carcinoma models. Significant inhibition of tumor angiogenesis was found in the tumor tissues. The titers of autoantibodies against murine endoglin were significantly increased and the antibody levels lasted longer in the mice with combined endoglin DNA and recombinant protein vaccination. CTL response against endoglin-positive HUVECs, but not against endoglin-negative tumor cells was found in the mice combined DNA with protein vaccination. In addition, combination of endoglin DNA and recombinant protein vaccination significantly induced IFN-gamma secreting cells. These observations suggested that a combination of endoglin DNA and recombinant protein immunization as a vaccine strategy was superior to those using endoglin DNA or recombinant protein alone as vaccines.
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PMID:Combination of recombinant xenogeneic endoglin DNA and protein vaccination enhances anti-tumor effects. 1769 Oct 24

We assessed the antitumor efficacy of KRN951, a novel tyrosine kinase inhibitor of vascular endothelial growth factor receptors, using a rat colon cancer RCN-9 syngeneic model in which the tumor cells are transplanted into the peritoneal cavity of F344 rats. KRN951 treatments that commenced 4 days after tumor transplantation (day 4) significantly inhibited tumor-induced angiogenesis, the formation of tumor nodules in the mesenteric windows, and the accumulation of malignant ascites. Moreover, KRN951 treatments initiated on day 14, by which time angiogenesis and malignant ascites have already been well established, resulted in the regression of newly formed tumor vasculatures with aberrant structures and also in the apparent loss of malignant ascites by the end of the study period. Quantitative analysis of the vessel architecture on mesenteric windows revealed that KRN951 not only regressed, but also normalized the tumor-induced neovasculature. Continuous daily treatments with KRN951 significantly prolonged the survival of rats bearing both early stage and more advanced-stage tumors, compared with the vehicle-treated animals. The results of our current study thus show that KRN951 inhibits colon carcinoma progression in the peritoneal cavity by blocking tumor angiogenesis, ascites formation, and tumor spread, thereby prolonging survival. Moreover, these studies clearly demonstrate the therapeutic effects of KRN951 against established tumors in the peritoneal cavity, including the regression and normalization of the tumor neovasculature. Our findings therefore suggest that KRN951 has significant potential as a future therapeutic agent in the treatment of peritoneal cancers with ascites.
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PMID:Anti-tumor activity and tumor vessel normalization by the vascular endothelial growth factor receptor tyrosine kinase inhibitor KRN951 in a rat peritoneal disseminated tumor model. 1820 Dec 72

The function of p53 tumor suppressor is often altered in various human tumors predominantly through missense-mutations resulting in accumulation of mutant proteins. We revealed that expression of p53 proteins with amino-acid substitutions at codons 175 (R175H), 248 (R248W), and 273 (R273H), representing the hot-spots of mutations in various human tumors, increased the number of vessels in HCT116 human colon carcinoma xenografts and, as a result, accelerated their growth. Stimulation of tumor angiogenesis was connected with about 2-fold increase in intracellular level of reactive oxygen species (ROS). Antioxidant N-acetyl-l-aspartate (NAC) decreased vessels number in tumors formed by cells with inactivated p53 and inhibited their growth. Effect of ROS on angiogenesis in tumors expressing hot-spot p53 mutants was correlated with their ability to increase a content of HIF1 transcriptional factor responsible for up-regulation of VEGF-A mRNAs.
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PMID:p53 hot-spot mutants increase tumor vascularization via ROS-mediated activation of the HIF1/VEGF-A pathway. 1909 59

It was proposed that increased level of mitochondrial reactive oxygen species (ROS), mediating execution of the aging program of an organism, could also be critical for neoplastic transformation and tumorigenesis. This proposal was addressed using new mitochondria-targeted antioxidant SkQ1 (10-(6'-plastoquinonyl) decyltriphenylphosphonium) that scavenges ROS in mitochondria at nanomolar concentrations. We found that diet supplementation with SkQ1 (5 nmol/kg per day) suppressed spontaneous development of tumors (predominantly lymphomas) in p53(-/-) mice. The same dose of SkQ1 inhibited the growth of human colon carcinoma HCT116/p53(-/-) xenografts in athymic mice. Growth of tumor xenografts of human HPV-16-associated cervical carcinoma SiHa was affected by SkQ1 only slightly, but survival of tumor-bearing animals was increased. It was also shown that SkQ1 inhibited the tumor cell proliferation, which was demonstrated for HCT116 p53(-/-) and SiHa cells in culture. Moreover, SkQ1 induced differentiation of various tumor cells in vitro. Coordinated SkQ1-initiated changes in cell shape, cytoskeleton organization, and E-cadherin-positive intercellular contacts were observed in epithelial tumor cells. In Ras- and SV40-transformed fibroblasts, SkQ1 was found to initiate reversal of morphological transformation of a malignant type, restoring actin stress fibers and focal adhesion contacts. SkQ1 suppressed angiogenesis in Matrigel implants, indicating that mitochondrial ROS could be important for tumor angiogenesis. This effect, however, was less pronounced in HCT116/p53(-/-) tumor xenografts. We have also shown that SkQ1 and related positively charged antioxidants are substrates of the P-glycoprotein multidrug resistance pump. The lower anti-tumor effect and decreased intracellular accumulation of SkQ1, found in the case of HCT116 xenografts bearing mutant forms of p53, could be related to a higher level of P-glycoprotein. The effects of traditional antioxidant N-acetyl-L-cysteine (NAC) on tumor growth and tumor cell phenotype were similar to the effects of SkQ1 but more than 1,000,000 times higher doses of NAC than those of SkQ1 were required. Extremely high efficiency of SkQ1, related to its accumulation in the mitochondrial membrane, indicates that mitochondrial ROS production is critical for tumorigenesis at least in some animal models.
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PMID:Mitochondria-targeted plastoquinone derivatives as tools to interrupt execution of the aging program. 3. Inhibitory effect of SkQ1 on tumor development from p53-deficient cells. 1912 16


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