Lysosomal disruption preferentially targets acute myeloid leukemia cells and progenitors
Mahadeo A. Sukhai, … , Guri Giaever, Aaron D. Schimmer
Mahadeo A. Sukhai, … , Guri Giaever, Aaron D. Schimmer
Published January 2, 2013; First published December 3, 2012
Citation Information: J Clin Invest. 2013;123(1):315-328. https://doi.org/10.1172/JCI64180.
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Categories: Research Article Oncology

Lysosomal disruption preferentially targets acute myeloid leukemia cells and progenitors

Abstract

Despite efforts to understand and treat acute myeloid leukemia (AML), there remains a need for more comprehensive therapies to prevent AML-associated relapses. To identify new therapeutic strategies for AML, we screened a library of on- and off-patent drugs and identified the antimalarial agent mefloquine as a compound that selectively kills AML cells and AML stem cells in a panel of leukemia cell lines and in mice. Using a yeast genome-wide functional screen for mefloquine sensitizers, we identified genes associated with the yeast vacuole, the homolog of the mammalian lysosome. Consistent with this, we determined that mefloquine disrupts lysosomes, directly permeabilizes the lysosome membrane, and releases cathepsins into the cytosol. Knockdown of the lysosomal membrane proteins LAMP1 and LAMP2 resulted in decreased cell viability, as did treatment of AML cells with known lysosome disrupters. Highlighting a potential therapeutic rationale for this strategy, leukemic cells had significantly larger lysosomes compared with normal cells, and leukemia-initiating cells overexpressed lysosomal biogenesis genes. These results demonstrate that lysosomal disruption preferentially targets AML cells and AML progenitor cells, providing a rationale for testing lysosomal disruption as a novel therapeutic strategy for AML.

Authors

Mahadeo A. Sukhai, Swayam Prabha, Rose Hurren, Angela C. Rutledge, Anna Y. Lee, Shrivani Sriskanthadevan, Hong Sun, Xiaoming Wang, Marko Skrtic, Ayesh Seneviratne, Maria Cusimano, Bozhena Jhas, Marcela Gronda, Neil MacLean, Eunice E. Cho, Paul A. Spagnuolo, Sumaiya Sharmeen, Marinella Gebbia, Malene Urbanus, Kolja Eppert, Dilan Dissanayake, Alexia Jonet, Alexandra Dassonville-Klimpt, Xiaoming Li, Alessandro Datti, Pamela S. Ohashi, Jeff Wrana, Ian Rogers, Pascal Sonnet, William Y. Ellis, Seth J. Corey, Connie Eaves, Mark D. Minden, Jean C.Y. Wang, John E. Dick, Corey Nislow, Guri Giaever, Aaron D. Schimmer

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Figure 1

Mefloquine exhibits cytotoxicity against AML cells in vitro.

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Mefloquine exhibits cytotoxicity against AML cells in vitro. (A) High-th...
(A) High-throughput screen of 100 known drugs (each represented by a diamond) in OCI-AML2 leukemia cells, ranked by EC50 value. (B) (R)- and (S)-mefloquine. (C) Effect of mefloquine treatment (24 hours) on mouse monocyte-derived dendritic cells, mouse bone marrow mononuclear cells, and MDAY-D2 mouse leukemia cells. Data represent the mean percent viability ± SD (Annexin V/PI staining) compared with vehicle-treated controls from 3 independent experiments. (D) Effect of mefloquine treatment (left panel, 30 hours; right panel, 48 hours) on viability (Annexin V/PI staining) of normal human hematopoietic cells (n = 9) and primary human AML samples (n = 17). EC50 values for each sample, calculated using the median effect method (see Methods). *P < 0.05; **P < 0.01; ***P < 0.005. Top bracket indicates comparison between mefloquine sensitive AML and normal samples. Line indicates comparison between all AML and normal samples. (E) Effect of mefloquine treatment (10 μM) on colony forming potential of normal human hematopoietic samples (n = 3) and primary human AML cells (n = 4). Data represent the mean percent inhibition of colony formation ± SD compared with untreated cells. (F) Effect of mefloquine pre-treatment (10 μM, 24 hours) on the engraftment of normal and leukemic cells. Data represent the percent engraftment of human CD45+CD33+ cells in mouse femurs. Each data point represents a single mouse.