Disulfiram/cytarabine eradicates a subset of acute myeloid leukemia stem cells with high aldehyde dehydrogenase...

Most patients with acute myeloid leukemia (AML) achieve complete remission (CR) after induction chemotherapy, however, in some patients, the disease subsequently relapses and may lead to death. Leukemia stem cells (LSC) have been identified as the main cause for recurrence. Increased aldehyde dehydrogenase (ALDH^high) activity in a variety of cancer stem cells prevents effective action of chemotherapeutic drugs. In this study, we found that approximately 50.7% of AML patients had ALDH^high, and the presence of ALDH^high stem cells was associated with poor cytogenetic prognosis. Lentiviral vector transduced ALDH^high leukemia cell lines are insensitive to the conventional chemotherapy drug cytarabine, and inhibition of ALDH activity by disulfiram (DSF) can increase the sensitivity of ALDH^high leukemia cells to cytarabine. Unlike traditional chemotherapy drugs, DSF is not toxic to healthy umbilical cord blood stem cells. An ALDH^high leukemia cell xenograft model was established using immunodeficient mice to mimic the disease environment, and DSF and cytarabine were found to eliminate the ALDH^high leukemia cells in transplanted mice while not affecting the healthy blood cells of mice. These findings suggest that DSF may have therapeutic potential by inhibiting ALDH activity and thereby increasing chemosensitivity.