Disulfiram/copper selectively eradicates AML leukemia stem cells in vitro and in vivo by simultaneous induction of ROS-JNK and inhibition of NF-\u03baB and Nrf2

Bing Xu,Shiyun Wang,Vinodh Kannappan,Manman Deng,Rongwei Li,Huijuan Dong,Kai Chen,Lingli He,Weiguang Wang,Jie Zha

doi:10.1038/cddis.2017.176

Abstract

Acute myeloid leukemia (AML) is a heterogeneous malignancy. Despite the advances in past decades, the clinical outcomes of AML patients remain poor. Leukemia stem cells (LSCs) is the major cause of the recurrence of AML even after aggressive treatment making, promoting development of LSC-targeted agents is an urgent clinical need. Although the antitumor activity of disulfiram (DS), an approved anti-alcoholism drug, has been demonstrated in multiple types of tumors including hematological malignancies such as AML, it remains unknown whether this agent would also be able to target cancer stem cells like LSCs. Here, we report the in vitro and in vivo activity of DS in combination with copper (Cu) against CD34+/CD38+ leukemia stem-like cells sorted from KG1α and Kasumi-1 AML cell lines, as well as primary CD34+ AML samples. DS plus Cu (DS/Cu) displayed marked inhibition of proliferation, induction of apoptosis, and suppression of colony formation in cultured AML cells while sparing the normal counterparts. DS/Cu also significantly inhibited the growth of human CD34+/CD38+ leukemic cell-derived xenografts in NOD/SCID mice. Mechanistically, DS/Cu-induced cytotoxicity was closely associated with activation of the stress-related ROS-JNK pathway as well as simultaneous inactivation of the pro-survival Nrf2 and nuclear factor-κB pathways. In summary, our findings indicate that DS/Cu selectively targets leukemia stem-like cells both in vitro and in vivo, thus suggesting a promising LSC-targeted activity of this repurposed agent for treatment of relapsed and refractory AML.

Highlights

Despite the conventional multi-drug combinational therapies, the most preferred and efficacious treatment, have largely improved the long-term disease-free survival (DFS) of patients with acute myeloid leukemia (AML), virtually all of these patients will eventually relapse owing to drug-resistant Leukemia stem cells (LSCs) that are not eradicated by current standard therapies
We report that DS in combination with Cu has a potent and selective anti-leukemia property in vitro against leukemia stem-like cells (e.g., CD34+/CD38− KG1α and Kasumi-1 cells and primary CD34+ cells isolated from AML patients) as well as is highly effective in vivo in CD34+/CD38− leukemic cell-derived xenograft mouse models, in association with induction of apoptosis via activation of the stress-related Reactive oxygen species (ROS)-jun NH2-terminal kinase (JNK) pathway and inhibition of the pro-survival Nrf[2] and Nuclear factor-κB (NF-κB) pathways
Leukemia stem-like cells were enriched from KG1α cell line, a subclone cell line of KG1 cells, by sorting a CD34+/CD38− cell population using fluorescenceactivated cell sorting (FACS)

Summary

Introduction

Despite the conventional multi-drug combinational therapies, the most preferred and efficacious treatment, have largely improved the long-term disease-free survival (DFS) of patients with AML, virtually all of these patients will eventually relapse owing to drug-resistant LSCs that are not eradicated by current standard therapies. This has become a major hindrance to success of AML treatment.[5] To prolong the duration of DFS as well as overall survival, new therapeutic agents targeting LSCs with low/non systemic toxicity are urgently needed for AML treatment. Disulfiram (DS) is a Food and Drug Administration (FDA)-approved anti-alcoholism drug that has been used in clinic for 460 years.[9,10] As a divalent metal ion chelator, DS is able to strongly chelate copper (Cu) to form a disulfiram/

Methods

Results

Conclusion