Marked downregulation of the granulopoiesis regulator LEF1 is associated with disease progression in the myelodysplastic syndromes.

Lymphoid enhancer-binding factor 1 (LEF1) is a neutrophilic granulopoiesis regulator whose absence is critical in congenital neutropenia. We have shown LEF1 downregulation in the CD34(+) cells of the majority of myelodysplastic syndromes (MDS) patients. LEF1 was the most significant differentially expressed gene between early and advanced MDS. Marked LEF1 downregulation was found in 27/32 patients with advanced MDS and in 6/35 patients with early MDS, and was associated with neutropenia. Downregulation of LEF1 mRNA was reflected at the protein level. Immunostaining for CD34/LEF1 may represent a marker of advanced MDS. LEF1 may play a role in the defective maturation of myeloid progenitors in MDS.