title: [Effects of CD/5-FC suicide gene therapy system on human malignant glioma cells in vitro].
abstract: OBJECTIVE
  To investigate the killing effects of cytosine deaminase/5-fluorocytosine (CD/5-FC) suicide gene therapy system on human malignant glioma cells in vitro.
  
  
  METHODS
  The pCMVCD plasmid was transfected into the U251 human malignant glioma cells using Lipofectamine 2000-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 the number of viability cells (or cytotoxicity assay), and 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 the high-performance liquid chromatography (HPLC) analysis.
  
  
  RESULTS
  The untreated U251 cells were insensitive to 5-FC, with the IC50 about 6 500 micromol/L. After the transfection, the IC50 was dramatically reduced to about 10 micromol/L. Therefore, gene transfection made G418-resistant clones (U251/CD cells) highly sensitive to 5-FC. HPLC analysis showed that 5-FU was detected in U251/CD cell medium.
  
  
  CONCLUSIONS
  The killing effects of U251 cells modified by CD gene were induced by 5-FC, and the CD/5-FC system was feasible to treat glioma.
authors.affiliation: Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, China. lvsq0518@yahoo.com.cn
authors.forename: Sheng-Qing
authors.initials: SQ
authors.lastname: Lü
authors.forename: Yun-Sheng
authors.initials: YS
authors.lastname: Liu
authors.forename: Hui
authors.initials: H
authors.lastname: Yang
mesh_terms: D001932:Brain Neoplasms / Q000235:genetics* / Q000628:therapy; D043525:Cytosine Deaminase / Q000235:genetics*; D005437:Flucytosine / Q000378:metabolism*; D005472:Fluorouracil / Q000494:pharmacology*; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D005910:Glioma / Q000235:genetics* / Q000628:therapy; D006801:Humans; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D005437:Flucytosine; D043525:Cytosine Deaminase; D005472:Fluorouracil