Selective apoptosis of multiple myeloma cells in primary samples induced by arsenic trioxide

Objectives Currently, multiple myeloma (MM) is an incurable disease. Despite the fact that arsenic trioxide (ATO) shows promising results in vitro, data from treatment of patients with MM are disappointing. Due to these discrepancies, we compared the efficacy and selectivity of ATO at two different concentrations in samples from MM patients. Methods The extent of apoptosis induced by 2 and 5 µM ATO was evaluated by flow cytometry using annexin V. 34 diagnostic bone marrow samples obtained from MM patients were analysed. Results 5 µM ATO efficiently induced apoptosis in primary samples. Besides efficacy, also selectivity of action on MM cells in comparison to remaining haematopoietic cells was demonstrated for 5 µM ATO but not for 2 µM ATO. Discussion Our study on primary samples confirmed that ATO has a potential role in therapeutic management of MM. Further controlled studies on MM patients are needed.