Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although unmethylated CpG dinucleotide-containing oligodeoxynucleotides (CpG ODN) are able to inhibit tumor metastasis through the induction of antitumor immunity, their stability and delivery to antigen presenting cells needs to be improved. In this study, we formulated a CpG ODN complex with cationic liposomes (CpG ODN-lipoplex) and its antitumor activity was evaluated in peritoneal dissemination models of tumor cells stably labeled with firefly luciferase gene. A single intraperitoneal administration of CpG ODN-lipoplex greatly reduced the number of tumor cells to 0.01% or lower compared with that detected in untreated mice, which may be associated with increased production of TNF-alpha and IL-12. CpG ODN-lipoplex increased the survival time of the tumor-bearing mice, and most long-term survivors rejected rechallenged tumor cells. These results indicate that a single dosing of CpG ODN-lipoplex is effective in inhibiting peritoneal dissemination and inducing long-lasting antitumor immunity.
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PMID:Inhibition of peritoneal dissemination of tumor cells by single dosing of phosphodiester CpG oligonucleotide/cationic liposome complex. 1699 62

Approaches to improve the oncolytic potency of replication-competent adenoviruses include the insertion of therapeutic transgenes into the viral genome. Little is known about the levels and duration of in vivo transgene expression by cells infected with such "armed" viruses. Using a tumor-selective adenovirus encoding firefly luciferase (AdDelta24CMV-Luc) we investigated these questions in an intracranial mouse model for malignant glioma. Luciferase expression was detected by bioluminescence imaging, and the effect of the immunosuppressive agent cyclophosphamide (CPA) on transgene expression was assessed. Intratumoral AdDelta24CMV-Luc injection led to a localized dose-dependent expression of luciferase. Surprisingly, this expression decreased rapidly during the course of 14 days. In contrast, mice injected with nonreplicating Ad.CMV-Luc demonstrated stable transgene expression. Treatment of mice with CPA in combination with AdDelta24CMV-Luc retarded the loss of transgene expression. Staining of mouse brains for inflammatory cells demonstrated decreased tumor infiltration by immune cells in CPA-treated mice. Moreover, in immunodeficient NOD/SCID mice loss of transgene expression was less rapid and not prevented by CPA treatment. Together, our data demonstrate that transgene expression and viral replication decrease rapidly after intratumoral injection of oncolytic adenovirus in mouse brains and that treatment with the immunomodulator CPA prolongs viral-mediated gene expression.
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PMID:Cyclophosphamide increases transgene expression mediated by an oncolytic adenovirus in glioma-bearing mice monitored by bioluminescence imaging. 1699 14

Although surgical removal is a primary option for treating tumors, it can lead to the increased growth of metastatic tumors. Because surgical procedures may generate reactive oxygen species (ROS), known promoters of tumor metastasis and growth, we investigated whether PEGylated catalase (PEG-catalase, plasma half-life of 13.6 h) was able to prevent this after surgical removal of a footpad tumor in mice. Murine melanoma cells labeled with the firefly luciferase gene were used to monitor the distribution of tumor cells. After inoculation into the footpad, tumor cells were found in the lung, and the number increased with time. The surgical removal of the footpad tumor significantly (p < 0.05) increased the number of metastatic tumor cells and the level of plasma lipoperoxides. An intravenous injection of PEG-catalase significantly (p < 0.05) suppressed the metastatic tumor growth as well as the peroxidation. Quantitative RT-PCR and Western blot analyses indicated that PEG-catalase markedly reduced the increase in the expression of epidermal growth factor receptor. These findings indicate that the removal of tumor produces ROS, which then aggravate metastatic tumor growth by activating several growth factors. PEG-catalase can effectively prevent this metastatic tumor growth by detoxifying the ROS.
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PMID:PEGylated catalase prevents metastatic tumor growth aggravated by tumor removal. 1702 72

To study the biodistribution of MSCs, we labeled adult murine C57BL/6 MSCs with firefly luciferase and DsRed2 fluorescent protein using nonviral Sleeping Beauty transposons and coinfused labeled MSCs with bone marrow into irradiated allogeneic recipients. Using in vivo whole-body imaging, luciferase signals were shown to be increased between weeks 3 and 12. Unexpectedly, some mice with the highest luciferase signals died and all surviving mice developed foci of sarcoma in their lungs. Two mice also developed sarcomas in their extremities. Common cytogenetic abnormalities were identified in tumor cells isolated from different animals. Original MSC cultures not labeled with transposons, as well as independently isolated cultured MSCs, were found to be cytogenetically abnormal. Moreover, primary MSCs derived from the bone marrow of both BALB/c and C57BL/6 mice showed cytogenetic aberrations after several passages in vitro, showing that transformation was not a strain-specific nor rare event. Clonal evolution was observed in vivo, suggesting that the critical transformation event(s) occurred before infusion. Mapping of the transposition insertion sites did not identify an obvious transposon-related genetic abnormality, and p53 was not overexpressed. Infusion of MSC-derived sarcoma cells resulted in malignant lesions in secondary recipients. This new sarcoma cell line, S1, is unique in having a cytogenetic profile similar to human sarcoma and contains bioluminescent and fluorescent genes, making it useful for investigations of cellular biodistribution and tumor response to therapy in vivo. More importantly, our study indicates that sarcoma can evolve from MSC cultures.
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PMID:Sarcoma derived from cultured mesenchymal stem cells. 1703 75

Hydrogen peroxide may aggravate the peritoneal dissemination of tumor cells by activating the expression of a variety of genes. In this study, we used pegylated catalase (PEG-catalase) to examine whether prolonged retention of catalase activity within the peritoneal cavity is effective in inhibiting peritoneal dissemination in mouse models. Murine B16-BL6 cells or colon 26 cells labeled with firefly luciferase gene were inoculated intraperitoneally into syngeneic mice. Compared with unmodified catalase, PEG-catalase was retained in the peritoneal cavity for a long period after intraperitoneal injection. A single injection of PEG-catalase just before tumor inoculation significantly reduced the number of the tumor cells at 1 and 7 days. The changes in the expression of molecules involved in the metastasis were evaluated by real time quantitative PCR analysis. Inoculation of the tumor cells increased the expression of intercellular adhesion molecule (ICAM)-1 in the greater omentum, which was inhibited by PEG-catalase. An injection of PEG-catalase at 3 days after tumor inoculation also reduced the number of the tumor cells, suggesting that processes other than the adhesion of tumor cells to peritoneal organs are also inhibited. Daily doses of PEG-catalase significantly prolonged the survival time of tumor-bearing mice. These results indicate that intraperitoneal injection of PEG-catalase inhibits the multiple processes of peritoneal dissemination of tumor cells by scavenging hydrogen peroxide in the peritoneal cavity.
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PMID:Inhibition of adhesion and proliferation of peritoneally disseminated tumor cells by pegylated catalase. 1708 58

Mitogen-activated protein kinases (MAPK) play important roles in malignancy. The ability to detect and quantitate MAPKs in live animal models of cancer will facilitate an understanding of disease progression. We have developed a gene expression-based imaging system that detects and quantifies MAPK activity in prostate cancer tumors implanted into severe combined immunodeficient mice. The imaging technology uses a modified version of two-step transcriptional amplification (TSTA). The tissue specificity of gene expression is imparted by an enhanced version of the prostate-specific antigen regulatory region that expresses GAL4-ELK1. GAL4-ELK1 confers MAPK specificity by activating a firefly luciferase (FLuc) reporter gene when the Ets-like transcription factor (ELK) 1 activation domain is phosphorylated by MAPK. FLuc activity in live animals was detected using the Xenogen In vivo Imaging System. We validated the TSTA-ELK1 system by analyzing its response to epidermal growth factor treatment in transfected tissue culture cells and in adenovirus (AdTSTA-ELK1)-injected prostate cancer xenograft tumors. We measured MAPK activity in two well-characterized xenograft models, CWR22 and LAPC9. Although no significant differences in MAPK levels were detected between androgen-dependent and androgen-independent xenografts, the CWR22 models display significantly higher levels of AdTSTA-ELK1 activity versus LAPC9. Western blots of tumor extracts showed that the elevated imaging signal in CWR22 xenografts correlated with elevated levels of phosphorylated extracellular signal-regulated kinase 1/2 but not p38 or c-Jun NH(2)-terminal kinase. We conclude that a gene expression-based optical imaging system can accurately detect and quantify MAPK activity in live animals.
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PMID:Imaging mitogen-activated protein kinase function in xenograft models of prostate cancer. 1710 14

To inhibit peritoneal dissemination of tumor cells by destroying hydrogen peroxide, ethylenediamine-conjugated catalase (ED-catalase), a cationized derivative, was injected into the peritoneal cavity of mice. ED-catalase had about a 6-fold longer retention time within the cavity than unmodified catalase. Peritoneal dissemination was evaluated after intraperitoneal inoculation of B16-BL6/Luc, a melanoma clone stably expressing firefly luciferase, by measuring luciferase activity. An intraperitoneal injection of ED-catalase just before tumor inoculation significantly reduced the number of tumor cells in peritoneal organs. Catalase was less effective, confirming the importance of the retention of the enzyme within the cavity for the inhibition. ED-catalase injected 3 days after tumor inoculation was also effective in inhibiting tumor growth. A real-time quantitative PCR analysis revealed that ED-catalase significantly suppressed the expression of intercellular adhesion molecule-1. Daily dosing of ED-catalase for 7 days significantly prolonged the survival of tumor-bearing mice. These findings indicate that ED-catalase, which is retained for a long time within the peritoneal cavity, is highly effective in inhibiting the adhesion and proliferation of peritoneally disseminated tumor cells, and in increasing the survival of tumor-bearing mice.
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PMID:Inhibition of peritoneal dissemination of tumor cells by cationized catalase in mice. 1738 24

Multimodality imaging using several reporter genes and imaging technologies has become an increasingly important tool in determining the location(s), magnitude, and time variation of reporter gene expression in small animals. We have reported construction and validation of several triple fusion genes composed of a bioluminescent, a fluorescent, and a positron emission tomography (PET) reporter gene in cell culture and in living subjects. However, the bioluminescent and fluorescent components of fusion reporter proteins encoded by these vectors possess lesser activities when compared with the bioluminescent and fluorescent components of the nonfusions. In this study, we first created a mutant (mtfl) of a thermostable firefly luciferase (tfl) bearing the peroxisome localization signal to have greater cytoplasmic localization and improved access for its substrate, d-luciferin. Comparison between the three luciferases [mtfl, tfl, and firefly luciferase (fl)] both in cell culture and in living mice revealed that mtfl possessed 6- to 10-fold (in vitro) and 2-fold (in vivo) higher activity than fl. The improved version of the triple fusion vector carrying mtfl as the bioluminescent reporter component showed significantly (P < 0.05) higher bioluminescence than the previous triple fusion vectors. Of the three different red fluorescent reporter genes (jred, hcred, and mrfp1, isolated from jellyfish chromophore, coral Heteractis crispa, and coral Discosoma, respectively) evaluated, mrfp1 was able to preserve highest expression as a component of the triple fusion reporter gene for in vivo fluorescence imaging. A truncated version of wild-type herpes simplex virus 1 (HSV1) thymidine kinase gene (wttk) retained a higher expression level than the truncated mutant HSV1-sr39 TK (ttk) as the third reporter component of this improved triple fusion vector. Multimodality imaging of tumor-bearing mice using bioluminescence and microPET showed higher luciferase activity [(2.7 +/- 0.1 versus 1.9 +/- 0.1) x (10(6) p/s/cm(2)/sr)] but similar level of fluorine-18-labeled 2'-fluoro-2'-deoxyarabinofuranosyl-5-ethyluracil (18F-FEAU) uptake (1.37 +/- 0.15 versus 1.37 +/- 0.2) percentage injected dose per gram] by mtfl-mrfp1-wttk-expressing tumors compared with the fl-mrfp1-wttk-expressing tumors. Both tumors showed 4- to 5-fold higher accumulation (P < 0.05) of 18F-FEAU than fluorine-18-labeled 9-(4-fluoro-3-hydroxymethylbutyl)guanine. This improved triple fusion reporter vector will enable high sensitivity detection of lower numbers of cells from living animals using the combined bioluminescence, fluorescence, and microPET imaging techniques.
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PMID:Construction and validation of improved triple fusion reporter gene vectors for molecular imaging of living subjects. 1740 15

Firefly luciferase (Fluc) has been widely used as a reporter gene. The aim of this study was to investigate immune response to luciferase protein after an intradermal injection of pcDNA3.1-Fluc in immunocompetent BALB/c mice. We observed bioluminescence at injection sites from one to seven days post-injection when pcDNA3.1-Fluc was intradermally injected into ear-pinnae. To observe induced immune response, the percentages of CD8+IFNgamma+ cells in the draining lymphoid cells of immunocompetent BALB/c mice immunized by pcDNA3.1-Fluc were measured. And the tumor growths of CT26/Fluc in pcDNA3.1-Fluc group were monitored by observing bioluminescent signals and measuring tumor mass, and these were compared with those of the pcDNA3.1 group in immunocompetent BALB/c mice and immunodeficient Nu/Nu mice. In the immunocompetent BALB/c mice, percentages of CD8+IFNgamma+ cells in the pcDNA3.1-Fluc group were higher than those in the pcDNA3.1 group. Ten days after tumor inoculation, tumor growth inhibition was found in the pcDNA3.1-Fluc group, but not in the pcDNA3.1 group in the immunocompetent BALB/c mice. No significant difference in tumor growth inhibition was observed when CT26/Fluc was injected into immunodeficient Nu/Nu mice. In terms of cytokine profiles of draining lymphoid cells of immunized mice, IFNgamma protein levels in the pcDNA3.1-Fluc group were higher than in pcDNA3.1 group animals among the immunocompetent BALB/c mice. In conclusion, Fluc induced a Th1 immune response to Fluc protein delivered by injecting pcDNA3.1-Fluc into immunocompetent BALB/c mice. We suggest that immune response to the Fluc gene is cautionary in preclinical or clinical trials involving the Fluc gene, and that the immunologic potential of firefly luciferase as a naked DNA may be useful in cancer immunotherapy.
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PMID:Immune response to firefly luciferase as a naked DNA. 1749 21

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can selectively kill tumor cells and, in combination with other agents, could enhance tumor therapy. We explored the combined therapeutic effects of a secretable form of (S) TRAIL-induced apoptosis and the downregulation of Bcl-2 in human gliomas. We constructed a lentiviral delivery system: 1) for the expression of short hairpin (sh) RNA to downregulate Bcl-2 and for the expression of S-TRAIL to induce apoptosis in glioma cells; and 2) to follow delivery in vitro and the fate of tumors in real time in vivo. We demonstrate that lentiviral-mediated simultaneous downregulation of Bcl-2 and S-TRAIL-induced apoptosis leads to an increased expression of activated caspase-3 and caspase-7, thus resulting in accelerated S-TRAIL-mediated apoptosis in glioma cells in vitro. Using a highly malignant human glioma model expressing EGFRvIII and firefly luciferase, we show that the combined effect of Bcl-2 downregulation and S-TRAIL-induced apoptosis results in complete eradication of gliomas compared to S-TRAIL monotherapy. These results show that simultaneous triggering of TRAIL-mediated death receptor pathway and downregulation of Bcl-2 by shRNA leads to enhanced eradication of gliomas and serves as a template in developing and monitoring combination therapies for the treatment of drug-resistant cancers.
Neoplasia 2007 May
PMID:Tumor therapy mediated by lentiviral expression of shBcl-2 and S-TRAIL. 1753 49


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