Taurolidine inhibits tumor cell growth in vitro and in vivo

Background: Taurolidine, a derivative of the amino acid taurine, exhibits a ntiendotoxin, antibacterial, and antiadherence activity. We hypothesized th at Taurolidine may inhibit tumor cell growth, both in an in vitro and in vi vo setting. Our aim was to examine the effect of Taurolidine on the growth of a rat metastatic colorectal tumor cell line (DHD/K12/TRb) in vitro and i n vivo. Methods: In the in vitro experiments, DHD/K12/TRb cells were incubated with 5, 10, 15, 25, mu g/ml of Taurolidine. Cells incubated in culture medium a lone were used as controls. Cell proliferation, cell viability, cell death, and cell apoptosis were measured using commercially available techniques. In the in vivo experiment, ED IX rats were randomized into two groups (n = 10/group). Group A (control) underwent laparotomy and instillation of DHD/K 12/TRb tumor cells intraperitoneally followed by phosphate buffered saline (PBS). Group B received Taurolidine (100 mg/kg) instead of PBS. Animals wer e killed after 24 days and tumor burden assessed by counting the number of tumor nodules in the peritoneal cavity. Results: Incubation of the tumor cells with Taurolidine resulted in a 4-fol d decrease in proliferation rates (25 +/- 4% vs. 100 +/- 28% for controls) and a 4-fold increase in cell necrosis as demonstrated by the increase in L DH release (403 +/- 28% vs. 100 +/- 26% for controls), at a Taurolidine con centration of 25 mu g/ml. A dose-dependent decrease in cell viability was a lso observed. In the in vivo study, local Taurolidine administration result ed in significant decreases in tumor burden (3 +/- 1 nodules in Group B ani mals vs. 649 +/- 101 nodules in Group A animals). Conclusions: Taurolidine inhibits the growth of a rat metastatic colorectal tumor cell Line in vitro and in vivo and thus may have potential in the pr evention of peritoneal metastases.