STAT activation status differentiates leukemogenic from non-leukemogenic stem cells in AML and is suppressed by arsenic in t(6;9)-positive AML
Claudia Oancea1, Brigitte Rüster2, Boris Brill3, Jessica Roos1, Maria Heinssmann1, Gesine Bug1, Afsar Ali Mian1, Nathalie Andrea Guillen1, Steven M. Kornblau4, Reinhard Henschler2,5 and Martin Ruthardt1
1 Department of Hematology, Goethe University, Frankfurt, Germany
2 Department of Transfusion Medicine and Immunohematology, Goethe University, Frankfurt, Germany
3 Georg-Speyer-Haus, Institute for Biomedical Research, Frankfurt am Main, Germany
4 Section of Molecular Hematology and Therapy, Department of Leukemia, The University of Texas, MD Anderson Cancer Center, Houston, TX, USA
5 University Clinic Munich, Department for Transfusion Medicine, Cell Therapy and Hemostaseology, Munich, Germany
Correspondence:
Martin Ruthardt, email:
Keywords: leukemia initiating cell; t(6;9); STAT5; arsenic trioxide
Received: September 19, 2014 Accepted: October 19, 2014 Published: October 19, 2014
Abstract
Acute myeloid leukemia (AML) is characterized by an aberrant self-renewal of hematopoietic stem cells (HSC) and a block in differentiation. The major therapeutic challenge is the characterization of the leukemic stem cell as a target for the eradication of the disease. Until now the biology of AML-associated fusion proteins (AAFPs), such as the t(15;17)-PML/RARα, t(8;21)-RUNX1/RUNX1T1 and t(6;9)-DEK/NUP214, all able to induce AML in mice, was investigated in different models and genetic backgrounds, not directly comparable to each other. To avoid the bias of different techniques and models we expressed these three AML-inducing oncogenes in an identical genetic background and compared their influence on the HSC compartment in vitro and in vivo.
These AAFPs exerted differential effects on HSCs and PML/RARα, similar to DEK/NUP214, induced a leukemic phenotype from a small subpopulation of HSCs with a surface marker pattern of long-term HSC and characterized by activated STAT3 and 5. In contrast the established AML occurred from mature populations in the bone marrow. The activation of STAT5 by PML/RARα and DEK/NUP214 was confirmed in t(15;17)(PML/RARα) and t(6;9)(DEK/NUP214)-positive patients as compared to normal CD34+ cells. The activation of STAT5 was reduced upon the exposure to Arsenic which was accompanied by apoptosis in both PML/RARα- and DEK/NUP214-positive leukemic cells. These findings indicate that in AML the activation of STATs plays a decisive role in the biology of the leukemic stem cell. Furthermore we establish exposure to arsenic as a novel concept for the treatment of this high risk t(6;9)-positive AML.
