In vitro efficacy of cinnarizine against lymphoma and multiple myeloma.

Background/Aim: Multiple myeloma, a well-known but still incurable disease, is a hematological malignancy of B-lymphocytes. While standard chemotherapy regimens have been used for years, novel agents, such as lenalidomide and bortezomib, have become an essential part of today's therapies. Nevertheless, new therapeutical strategies are required in the future. Aberrant activation of wingless-related integration site (WNT)/beta-catenin signaling promotes the development of several types of cancer. Recently, it has been demonstrated that the WNT pathway is also activated in lymphoma and myeloma. Thus, the WNT signaling molecules are attractive candidates for the development of targeted therapies. To this extent, we recently confirmed that the diuretic agent ethacrynic acid (EA) and the antifungal agent ciclopirox olamine (CIC) inhibit WNT signaling. Cinnarizine has similar chemical features to those of CIC. Materials and Methods: Thus, in this study the antitumor effect of cinnarizine on myeloma and lymphoma cells was investigated by DiOC6 and propidium iodide (PI)-staining in flow cytometry. Results: Cinnarizine triggered a significant apoptotic activity in all tested myeloma and lymphoma cell lines in a concentration-dependent manner. Interestingly, healthy cells were mainly unaffected. Conclusion: These results reveal a significant selective induction of apoptosis by cinnarizine that might result from an inhibition of WNT signaling and suggest an in vivo efficacy against lymphoma and myeloma.