Objective: To investigate the therapeutic effect of a novel suicide gene system, yeast cytosine deaminase (YCD)/5-Fluorocytosine(5-FC), on P388/DBA murine leukemia model. Methods: P388-YCD-eGFP clone was selected afte...Objective: To investigate the therapeutic effect of a novel suicide gene system, yeast cytosine deaminase (YCD)/5-Fluorocytosine(5-FC), on P388/DBA murine leukemia model. Methods: P388-YCD-eGFP clone was selected after retrovirus transduction by limited dilution. P388-eGFP and wild type (wt) P388 cells were used as controls. (1) Tumorigenesis study: DBA mice were inoculated intravenously with P388-YCD-eGFP, P388-eGFP or wt P388 cells at a dosage of 5×10~6 per mouse (n=5). (2) Therapeutic effect study of 5-FC: After inoculation with P388-YCD-eGFP, P388-eGFP or wt P388 cells (n=5), 5-FC was administered at a dosage of 5 μmol/d in each mouse for 2 weeks. 20 μmol/d 5-FC were administered on the 8~ th day in case 5 μmol/d did not work. The percentage of eGFP^+ cells was detected by flow cytometry, frozen section or HE section. Results: Mice in YCD, eGFP and wt P388 group developed leukemia and survived (8.0±1.0) d, (7.6±0.89) d and (7.8±1.64) d (P>0.05), respectively. After being treated with 5-FC for 2 weeks, mice in YCD and eGFP^+ groups survived (13.2±1.79) d and (8.4±0.58) d (P<0.05). When 20 μmol/d 5-FC was administered, the percentage of eGFP^+ cells dropped from 21.9%±16.09% to 5.4%±5.6%, as well detected by FACS within 24h after treatment. Conclusion: 5-FC can eliminate YCD gene modified cells in vivo when cells are inoculated intravenously. YCD is an efficient suicide gene system in vivo.展开更多
基金Supported in part by grants from"Outstanding physicianProgram" of public Health Department of ShanghaiMunicipal Government,China(98BR0 2 9),National NaturalScience Foundation of China(30 170 379
文摘Objective: To investigate the therapeutic effect of a novel suicide gene system, yeast cytosine deaminase (YCD)/5-Fluorocytosine(5-FC), on P388/DBA murine leukemia model. Methods: P388-YCD-eGFP clone was selected after retrovirus transduction by limited dilution. P388-eGFP and wild type (wt) P388 cells were used as controls. (1) Tumorigenesis study: DBA mice were inoculated intravenously with P388-YCD-eGFP, P388-eGFP or wt P388 cells at a dosage of 5×10~6 per mouse (n=5). (2) Therapeutic effect study of 5-FC: After inoculation with P388-YCD-eGFP, P388-eGFP or wt P388 cells (n=5), 5-FC was administered at a dosage of 5 μmol/d in each mouse for 2 weeks. 20 μmol/d 5-FC were administered on the 8~ th day in case 5 μmol/d did not work. The percentage of eGFP^+ cells was detected by flow cytometry, frozen section or HE section. Results: Mice in YCD, eGFP and wt P388 group developed leukemia and survived (8.0±1.0) d, (7.6±0.89) d and (7.8±1.64) d (P>0.05), respectively. After being treated with 5-FC for 2 weeks, mice in YCD and eGFP^+ groups survived (13.2±1.79) d and (8.4±0.58) d (P<0.05). When 20 μmol/d 5-FC was administered, the percentage of eGFP^+ cells dropped from 21.9%±16.09% to 5.4%±5.6%, as well detected by FACS within 24h after treatment. Conclusion: 5-FC can eliminate YCD gene modified cells in vivo when cells are inoculated intravenously. YCD is an efficient suicide gene system in vivo.
