[Studies on thymidine kinase gene (TK) and GCV system for treatment of human retinoblastoma (RB)].

The antitumor effect of herpes simplex virus thymidine kinase (HSV-TK)/GCV system on human retinoblastoma (RB) was studied here. A retroviral vector with tk gene (pLXSN-TK) was transduced into packaging cell line PA317. Recombinant retroviral was obtained and employed to infect human RB cells. The in vitro efficacy of TK/GCV was evaluated by survival rate of RB cells with and without TK transduced 5 days after treated with GCV. A nude mouse model with heteroplantation of human RB was established to examine the in vivo efficacy. Mice with RB were given an in situ injection of retrovirus followed by treatment with GCV for 14 days (50 mg/kg). The RB/TK cells in tissue culture dish showed far more sensitive to GCV than RB cells. The tumors in RB mice with TK gene transduced were much smaller than those in control. The results indicate that HSV-TK/GCV system can suppress growth of RB both in vitro and in vivo. It could be a valuable method for treatment of RB patients.