Synthetic sphingolipid analogs and anti-cancer drugs synergistically induced human colon and pancreatic cancer cell death through inhibiting ceramide metabolism

Ceramide metabolism is a potential target for anti-cancer therapy. Studies show that chemotherapeutic agents can induce apoptosis and it is mediated by ceramide. Synthesized sphingolipid analogs can induce cell death in human lymphocytes and leukemia cells. By screening a group of synthetic sphingolipid analogs, we found that low concentrations of AD2750 and AD2646 induced cell death in human cancer cells by preventing ceramide from converting to sphingomyelin, individually or in combination with commercial cancer drugs. The combination of low concentrations of Taxol and AD2750 or AD2646 significantly increased cell death on human colon cancer cells (HT29). Co-administering low concentrations of Doxorubicin with AD2750 or AD2646 elevated cellular toxicity on human pancreatic cancer cells (CRL1687). This synergistic effect is related to the elevated cellular ceramide. Combining AD2750 or AD2646 with chemotherapy drugs can be used to manipulate ceramide and sphingomyelin metabolism, potentially to affect the growth of human cancer cells and increase the effectiveness of anti-cancer drugs on killing cancer cells.