Retroviral-mediated HSV-tk gene terapy on bladder cancdcer ex vivo and its hystander effect

Objective To observe the effects of hsv tk/gcv system on bladder cancer and its bystander effect by ex vivo. Methods HSV TK gene was transferred into urine bladder cancer cell line T739 by retrovirus in vitro. Tumors were induced in syngeneic mice by peritoneum injection with different ratio of T739 and T739TK cells. At the same time, subcutaneous tumors in back were established with parent T739 cells. After 6 days administration of GCV tumor volume and survival time were investigated. Result Tumor growth was inhibited and mice survival time prolonged with higher TK gene transfer ratio, when the ratio was above 50% subcutaneous tumor growth was also inhibited significantly. Conclusion The effects of hsv tk/gcv on bladder cancer is enhanced by higher gene transfer ratio and the distant bystander effect is found.