Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.4.1 (cytosine deaminase)
 747 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To study the possibility of oral gene therapy using live attenuated Salmonella, eukaryotic expression vectors EGFPN1, pLCDSN were introduced into a live attenuated AraA(-) auxotrophic mutant of Salmonella typhimurium (SL3261) and were administered orally to BALB/c and C57BL/6 mice. After six weeks, these mice were challenged with 4T(1) and Lewis cancer cells. Until the tumors reached to about 10 mm in diameter, 5-fluorocytosine was given through intraperitoneal injection. Flow cytometry, confocal microscopy and PCR methods were used to detect the integration and expression of the genes. The inhibition of the tumor and the survival time of the mice were also investigated. Results showed that cytosine deaminase gene integration could be detected in almost all kinds of mice tissue. And the GFP expression was much stronger in spleen and tumor than in other tissues. Cytosine deaminase/5-fluorocytosine system had significant antitumoractivities in vivo. The anti-tumor activities of cytosine deaminase/5-fluorocytosine at 500 mg/kg on 4T(1) and Lewis carcinoma in BALB/c and C57BL/6 mice were more potent than the efficiency of 5-fluorouracil 10 mg/kg(P 0.05). Therefor, this experiment demonstrates the potential value of live attenuated Salmonella as carrier for oral gene therapy.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2001
PMID:Treatment of Tumor in Mice by Oral Administration of Cytosine Deaminase Gene Carried in Live Attenuated Salmonella. 1205 Aug 17

A replication-defective recombinant adenovirus vector containing CMV promoter and Escherichia coli cytosine deaminase (cd) gene (AdCMVCD) was constructed. It was shown by Southern blotting and RT-PCR that cd gene had been inserted into AdCMVCD and was expressed in the infected cells. The recombinant virus was purified by gradient centrifugation in CsCl and its titer was 1x10(15) pfu/L. HeLa and C6 cells infected with AdCMVCD(m.o.i=100) became sensitive to the prodrug 5FC, and the number of viable cells decreased to less than 20% of the control after treatment with 100 &mgr;mol/L 5FC. Significant bystander effect was also observed. When cells infected with AdCMVCD were mixed with wild type cells at a ratio of 3.3 : 96.7, more than 60% of the cells could be killed in the presence of 50 &mgr;mol/L 5FC. These results suggest that the AdCMVCD/5FC system may provide a new approach for gene therapy of cancers.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 1998
PMID:The Construction of an Adenovirus Vector Containing Cytosine Deaminase Gene and Its Application. 1217 77

The possibility of tumor-specific suicidal gene therapy of colorectalcarcinoma was investigated using carcinoembryonic antigen (CEA) -positive human colorectal carcinoma cell line LoVo and CEA-negative HeLa cell line as a model. After confirming cellular specificity of cea promoter by CAT assay, eukaryotic expression plasmid pCEACD was constructed in which the expresstion of E. coli cytosine deaminase (CD) gene was under the control of cea promoter. The expression of CD gene increased the sensitivity of LoVo cells to 5-fluorocytosine (5FC) by 750 fold, while the sensitivity of HeLa cells to 5FC was increased by only 7.5 fold. These results suggest that the expression of CD gene driven by cea promoter specifically killed CEA-positive colorectal carcinoma cells. Transmission electron microscopy and DNA fragmentation assay demonstrate that CD/5FC system induced apoptosis in LoVo cells.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 1998
PMID:Use of Carcinoembryonic Antigen Gene Promoter in Colorectal Carcinoma-specific Suicidal Gene Therapy. 1217 89

The recombinant retroviral vector pLCDSN containing E. coli cytosine deaminase gene was constructed. After packaging with PA317 cell line, the infectious particles were used to infect human colon carcinoma cell line LoVo. A single clone harbouring EC-CD gene was picked after G418 selection. There was no significant difference in cell growth curve or morphology between the LoVo/LCDSN and LoVo cells. Both of them were very sensitive to 5-FU in vitro (IC(50), approximately 0.5 &mgr;mol/L). However, the expression of the CD gene did increase the sensitivity of these cells to the nontoxic prodrug, 5-FC, decreasing the IC(50) for 5-FC from 22 000 &mgr;mol/L for parental LoVo cells to 13 &mgr;mol/L for LoVo/LCDSN cells. Obvious by side effect was also observed. When cells transduced with CD gene were mixed with wild type cells at a ratio of 30:70, above 80% of the cancer cells could be killed after treatment with a nontoxic concentration of 5-FC.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 1997
PMID:Expression of Cytosine Deaminase Gene in Human Colon Carcinoma Cells by Recombinant Retroviral Vector. 1221 18

The purpose of this paper is to investigate the antitumor effects of cytosine deaminase/5-fluorocytosine (CD/5-FC) suicide gene therapy system on human malignant glioma cells in vitro. The pCMVCD plasmid was constructed through the CD gene insertion in the multicloning site of eukaryotic expression vector pcDNA3.0, and confirmed by restriction endonuclease digestion/gene sequencing. The construct was subsequently transfected into the U251 human malignant glioma cells by using LipofectAMINE2000-mediated method. Resistant clones (named U251/CD cells) were isolated by screening with G418 presence. U251/CD cells were incubated with 5-FC in different concentrations to determine viability ratios (or cytotoxicity assay), measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The concentrations of 5-fluorouracil (5-FU) in the media were measured by high-performance liquid chromatography (HPLC) detector. Our results suggested that the untreated U251 cells were insensitive to 5-FC, with the IC(50) about 6500 micromol/L. After transfection, the IC(50) was dramatically reduced to about 10 micromol/L. Therefore, gene transfection made G418-resistant clones (U251/CD cells) be highly sensitive to 5-FC. HPLC analysis showed that 5-FU was detected in U251/CD cell medium. Study on U251 cells genetically modified by CD gene in vitro will play an essential role in glioma gene therapy in vivo. In conclusion, our results indicated that the CD/5-FC system was feasible to treat glioma.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2003 May
PMID:Effects of CD/5-FC suicide gene therapy system on human malignant glioma cells in vitro. 1276 3