Allium sativum potentiates suicide gene therapy for murine transitional cell carcinoma

This study evaluated the synergistic effect of Allium sativum (AS) with sui cide gene therapy for transitional cell carcinoma (TCC) of the bladder. Sub cutaneous TCCs were established in syngeneic C3H/He mice with I x 10(5) MBT -2 cells. AS liquid extract was injected at the site of rumor transplantati on on Day 1 for three weeks (Experiment I) and into the established tumors weekly for five weeks (Experiment II) in combination with or without gene t herapy using a replication-defective adenoviral vector containing a herpes simplex virus thymidine kinase (HSV-TK) gene under the transcriptional cont rol of Rous sarcoma virus (RSV) promoter (Ad-RSV-TK,, 5 x 10(8) plaque-form ing units) plus ganciclovir (20 mg/kg/day ip). AS demonstrated a statistica lly significant reduction in incidence of TCC (cumulative dose 25 mg of AS) . Combination AS-suicide gene therapy significantly inhibited the tumor gro wth compared with the controls; which was evidenced by apoptosis on histomo rphological and immunohistochemical studies. These results suggest that AS had a definite antitumor effect in inhibiting tumorigenesis and growth of T CC in a murine model. AS treatment combined with suicide gene therapy had s ignificant additive antitumor effects on TCC and may provide a novel and ef fective treatment modality for TCC of the bladder.