OBJECTIVE: To evaluate the killing effects of the cytosine deaminase (CD) gene mediated by adenovirus vector on human pancreatic cancer cell lines in vitro. METHODS: The CD gene was cloned into pAdTrack-CMV-CD, and pA...OBJECTIVE: To evaluate the killing effects of the cytosine deaminase (CD) gene mediated by adenovirus vector on human pancreatic cancer cell lines in vitro. METHODS: The CD gene was cloned into pAdTrack-CMV-CD, and pAdTrack-CMV-CD and pAdEasy-l were recombinated in bacteria. The newly recombinated Ad-CD containing green fluoreseent protein (GFP) was propagated in 293 cells and purified by cesium chloride gradient centrifugation. Human pancreatic cancer cell lines Patu8988 and SW1990 were infected with this virus, then 5-FC was added. XTT assay was used to estimate relative numbers of viable cells. RESULTS: The positive clones were selected by using endonuclease to digest the combinatants and the concentration of viral liquids containing the CD gene was 2×1O^(11) pfu/ml. It was found that significant cytotoxic activities were possesscd by 5-FC for the CD gene transduced pancreatic cell lines, but little effects exerted on the nontransduced pancreatic carcinoma cells. CONCLUSIONS: The CD gene mediated by adenovirus with a high infectivity is efficient for gene therapy of pancreatic carcinoma cell lines. These data demonstrate the therapeutic efficacy of an enzyme prodrug strategy in experimental pancreatic cancer.展开更多
Cytosine deaminase gene of Escherichia coli strain H30 was cloned, and its initiation codon of ’GTG’ was mutated to ’ATG’ by PCR. Prokaryotic recombinant expression vector pBV220CD was constructed. Clone with high...Cytosine deaminase gene of Escherichia coli strain H30 was cloned, and its initiation codon of ’GTG’ was mutated to ’ATG’ by PCR. Prokaryotic recombinant expression vector pBV220CD was constructed. Clone with high enzyme activity were selected by detecting their specific activity of cytosine deaminase. 5FC（5FC, 5fluorocytosine） could induce the lethal toxicity to cells containing active CD gene. DNA sequence analysis indicated that there were 16 altered bases and 5 of them resulted in the alteration of amino acids in predicted peptide by comparing DNA sequence of the clone H30CD11 with high enzyme activity with CD gene reported in Gene Bank.展开更多
基金This work was supported by a grant from Shanghai Science Foundation (No. 994119044).
文摘OBJECTIVE: To evaluate the killing effects of the cytosine deaminase (CD) gene mediated by adenovirus vector on human pancreatic cancer cell lines in vitro. METHODS: The CD gene was cloned into pAdTrack-CMV-CD, and pAdTrack-CMV-CD and pAdEasy-l were recombinated in bacteria. The newly recombinated Ad-CD containing green fluoreseent protein (GFP) was propagated in 293 cells and purified by cesium chloride gradient centrifugation. Human pancreatic cancer cell lines Patu8988 and SW1990 were infected with this virus, then 5-FC was added. XTT assay was used to estimate relative numbers of viable cells. RESULTS: The positive clones were selected by using endonuclease to digest the combinatants and the concentration of viral liquids containing the CD gene was 2×1O^(11) pfu/ml. It was found that significant cytotoxic activities were possesscd by 5-FC for the CD gene transduced pancreatic cell lines, but little effects exerted on the nontransduced pancreatic carcinoma cells. CONCLUSIONS: The CD gene mediated by adenovirus with a high infectivity is efficient for gene therapy of pancreatic carcinoma cell lines. These data demonstrate the therapeutic efficacy of an enzyme prodrug strategy in experimental pancreatic cancer.
文摘Cytosine deaminase gene of Escherichia coli strain H30 was cloned, and its initiation codon of ’GTG’ was mutated to ’ATG’ by PCR. Prokaryotic recombinant expression vector pBV220CD was constructed. Clone with high enzyme activity were selected by detecting their specific activity of cytosine deaminase. 5FC（5FC, 5fluorocytosine） could induce the lethal toxicity to cells containing active CD gene. DNA sequence analysis indicated that there were 16 altered bases and 5 of them resulted in the alteration of amino acids in predicted peptide by comparing DNA sequence of the clone H30CD11 with high enzyme activity with CD gene reported in Gene Bank.
