title: DNA-liposome complexes transduction of herpes simplex virus thymidine kinase renders human tongue cancer cell line sensitive to ganciclovir in vitro.
abstract: OBJECTIVE
  To evaluate, in vitro, the cytotoxicity of the herpes simplex virus thymidine kinase (HSV1-tk) gene and ganciclovir (GCV) treatment, a widely used prodrug/suicide gene therapy, in human tongue cancer cell line Tbp-TL.
  
  
  METHODS
  Retrovirus expressing plasmid-liposome complex transduction was used. After treatment with G418 for 3 weeks, the integrated HSV1-tk gene was detected by PCR test with the primers specifically designed for HSV1-tk cDNA; HSV1-tk mRNA was detected with in situ hybridization method. In vitro cytotoxicity effect of HSV-GCV on Tbp-TL was detected with MTT and trypan blue exclusion test.
  
  
  RESULTS
  In vitro experiments demonstrated dose- and time-dependent cell death by transduction of the HSV1-tk gene followed by GCV treatment. The IC50 (the concentration required to elicit 50% growth inhibition) shifted from 1000 micrograms/mL in non-transduced Tbp-TL cells to 1.1 micrograms/mL in Tbp-TL/TK cells transduced with HSV1-tk gene, with the therapeutic index of 1000. Treatment with GCV at a dose of 10 micrograms/mL for 5 days led to complete cell death in HSV1-tk transduced tumor cells. When mixed with tk positive cells, the non-transduced cells (both the parent Tbp-TL cells as well as another non-transduced cell, the human muco-epidermoid carcinoma cell line M3SP2) were also killed by a degree associated with the percentage of tk positive cells. Seventy to 90% of the mixed cells were killed with only 10% to 20% tk positive cells involved.
  
  
  CONCLUSIONS
  These results suggest that the HSV-tk/GCV approach to human tongue cancer cell line may be efficacious, with a wide therapeutic range, and that it exerts a bystander effect in vitro.
authors: Department of Oral Biology, College of Stomatology, Fourth Military Medical University (FMMU), No. 1 Kang Fu Road, Xi'an 710032, P. R. China.
authors: J H
authors: JH
authors: Wang
authors: Z Q
authors: ZQ
authors: Situ
authors: J Z
authors: JZ
authors: Wu
authors: B
authors: B
authors: Liu
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use*; D000998:Antiviral Agents / Q000627:therapeutic use*; D018277:Carcinoma, Mucoepidermoid / Q000188:drug therapy; D016923:Cell Death / Q000235:genetics; D004396:Coloring Agents; D004279:DNA, Viral / Q000235:genetics*; D004305:Dose-Response Relationship, Drug; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D015774:Ganciclovir / Q000627:therapeutic use*; D015316:Genetic Therapy; D006801:Humans; D017403:In Situ Hybridization; D008081:Liposomes; D016133:Polymerase Chain Reaction; D011355:Prodrugs / Q000627:therapeutic use; D018139:Simplexvirus / Q000201:enzymology / Q000235:genetics*; D013778:Tetrazolium Salts; D013844:Thiazoles; D013937:Thymidine Kinase / Q000235:genetics*; D013997:Time Factors; D014062:Tongue Neoplasms / Q000188:drug therapy*; D014161:Transduction, Genetic; D014343:Trypan Blue; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D000998:Antiviral Agents; D004396:Coloring Agents; D004279:DNA, Viral; D008081:Liposomes; D011355:Prodrugs; D013778:Tetrazolium Salts; D013844:Thiazoles; D013937:Thymidine Kinase; C022616:thiazolyl blue; D014343:Trypan Blue; D015774:Ganciclovir