ABSTRACT
Abstract he level of transcription factor activity critically regulates cell fate decisions such as he matopoietic stem cell self-renewal and differentiation. The balance between hematopoietic stem cell self-renewal and differentiation needs to be tightly controlled, as a shift towards
differentiation might exhaust the stem cell pool while a shift towards self-renewal might mark the onset of leukemic transformation. A number of transcription factors have been proposed to be critically involved in governing stem cell fate and lineage commitment, such as HOX transcription factors, c-Myc, Notchl, P-Catenin, C/EBPa, PU.l and STATS. It is therefore no surprise that dysregulation of these transcription factors can also contribute to the development of leukemias. This review will discuss the role of STAT 5 in both normal and leukemic hematopoietic stem cells as well as mechanisms by which STAT5 can contribute to the development of human leukemias.
