Parameters Influencing the Efficiency of the Thymidine Kinase/Ganciclovir Strategy in Human Glioblastoma Cell Lines

The gene therapy strategy using the hsv1-thymidine kinase gene (TK) and ganciclovir (GCV) injections that has been used for treating human glioblastomas has not been as effective as expected after the first animal experiments. A better understanding of the different steps involved in this treatment, like gene transfer, gene expression, and sensitivity of the recipient cells is needed. Therefore, we studied 7 human glioblastoma cell lines (U87, U118, U251, SNB19, SNB75, SF295, SF539) for their sensitivity to the TK/GCV system. We also studied their in vitro bystander effect and their in vitro transfectability using LipofectAMINE as a transfection enhancer. According to this in vitro analysis, most of the glioblastoma cell lines should be sensitive to the TK/GCV system, but there is a significant need for agents to increase transfection efficiency.