Gene expression profile of primary human CD34+CD381o cells differentiating along the megakaryocyte lineage

Objective. To identify genes involved in megakaryopoiesis, high-density oligonucleotide microarrays were used to compare transcript profiles from undifferentiated CD34(+)CD38(lo) cells and culture-derived megakaryocytes (MKs). Materials and Methods. Megakaryocyte differentiation was achieved in vitro by inducing primary human CD34(+)CD38(lo) cells in serum-deprived media supplemented with the cytokine combination of interleukin-3, interleukin-6, stem cell factor, and thrombopoietin for 10 days. Three replicate microarray experiments were performed using hematopoietic cells isolated from three different organ donors and high-density oligonucleotide microarrays. Results. Analysis of gene array data resulted in 304 differentially expressed genes (P less than or equal to 0.001, fold change greater than or equal to3). A third of the 25 most highly up-regulated genes were known to participate in hemostasis (z = 6.75), and no genes known to be associated with MKs were among the down-regulated genes. We also found a large proportion of up-regulated transcripts in gene ontology categories of adhesion and receptor activity (85%) and signal transduction activity (68%). At the same time, 70% of genes within transcription factor functions were down-regulated. Confirmatory studies indicated that the array results correlated with mRNA and protein expression levels in primary MKs. Conclusion. This study provides a global expression profile of human MKs and a list of novel and previously uncharacterized candidate genes that are important components of megakaryopoiesis. (C) 2004 International Society for Experimental Hematology. Published by Elsevier Inc.