Suicide gene therapy for human uterine adenocarcinoma cells using herpes simplex virus thymidine kinase.
In gene therapy, the herpes simplex virus thymidine kinase (HSV-tk) gene is widely used as a suicide agent. Tumor cells expressing HSV-tk are sensitive to nucleoside analogs such as ganciclovir (GCV). An advantage of this system is the bystander killing effect whereby HSV-tk-positive cells exposed to GCV are lethal to surrounding HSV-tk-negative cells. We transfected the HSV-tk gene into a human cervical adenocarcinoma cell line, BU25TK-, and a human endometrial adenocarcinoma cell line, HHUA, by the Lipofectine method. The sensitivity of HSV-tk-positive cells to GCV and bystander killing effect on HSV-tk-negative cells were examined in vitro. HSV-tk-positive cells were sensitive to GCV at concentrations of 1 to 100 microg/ml in a dose- and time-dependent manner. The growth of HSV-tk-negative cells was inhibited when the population of cultured cells contained more than about 3% HSV-tk-positive cells. Moreover, for BU25TK- cells, HSV-tk-positive cells were injected into SCID mice subcutaneously and the effects of GCV therapy and bystander killing at a daily concentration of 25 mg/kg for 14 days were examined. HSV-tk-positive tumors transduced into SCID mice almost disappeared upon GCV treatment. Furthermore, tumor reduction was observed when mixtures of HSV-tk-negative cells containing more than 20% HSV-tk-positive cells were injected into SCID mice. In conclusion, the HSV-tk/GCV system might be applied to both cervical and endometrial adenocarcinoma.
Kunishige
I
I
Department of Obstetrics and Gynecology, Osaka University Medical School, 2-2 Yamadaoka, Suita, Osaka, 565, Japan.
Samejima
Y
Y
Shiki
Y
Y
Moriyama
A
A
Meruelo
D
D
Saji
F
F
Murata
Y
Y
D000230:Adenocarcinoma / Q000235:genetics / Q000628:therapy*; D000818:Animals; D005260:Female; D015774:Ganciclovir / Q000627:therapeutic use; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D018139:Simplexvirus / Q000235:genetics; D013937:Thymidine Kinase / Q000235:genetics; D014407:Tumor Cells, Cultured; D014594:Uterine Neoplasms / Q000235:genetics / Q000628:therapy*
D013937:Thymidine Kinase; D015774:Ganciclovir