¹Department of Medicine, Hematology and Oncology, University of Muenster, Münster, Germany

Correspondence: Dr C Müller-Tidow, Department of Medicine, Hematology and Oncology, University of Muenster, Albert-Schweitzer-Street 33, 48129 Muenster, Germany. E-mail: muellerc@uni-muenster.de

Received 9 January 2007; Revised 30 March 2007; Accepted 5 April 2007; Published online 7 June 2007.

Abstract

Wnt signaling plays an important role in stem cell self-renewal and proliferation. Aberrant activation of Wnt signaling and its downstream targets are intimately linked with several types of cancer with colon cancer being the best-studied example. However, recent results also suggest an important role of Wnt signaling in normal as well as leukemic hematopoietic stem cells. Aberrant activation of Wnt signaling and downstream effectors has been demonstrated in acute myeloid leukemia. Here, mutant receptor tyrosine kinases, such as Flt3 and chimeric transcription factors such as promyelocytic leukemia-retinoic acid receptor- and acute myeloid leukemia1-ETO, induce downstream Wnt signaling events. These findings suggest that the Wnt signaling pathway is an important target in several leukemogenic pathways and may provide a novel opportunity for targeting leukemic stem cells.