Tumor growth effects of rapamycin on human biliary tract cancer cells

BACKGROUND Liver transplantation is an important treatment option for patients with liver-originated tumors including biliary tract carcinomas (BTCs). Post-transplant tumor recurrence remains a limiting factor for long-term survival. The mammalian target of rapamycin-targeting immunosuppressive drug rapamycin could be helpful in lowering BTC recurrence rates. Therein, we investigated the antiproliferative effect of rapamycin on BTC cells and compared it with standard immunosuppressants. METHODS We investigated two human BTC cell lines. We performed cell cycle and proliferation analyses after treatment with different doses of rapamycin and the standard immunosuppressants, cyclosporine A and tacrolimus. RESULTS Rapamycin inhibited the growth of two BTC cell lines in vitro. By contrast, an increase in cell growth was observed among the cells treated with the standard immunosuppressants. CONCLUSIONS These results support the hypothesis that rapamycin inhibits BTC cell proliferation and thus might be the preferred immunosuppressant for patients after a liver transplantation because of BTC.