Identification of c-Myb Target Genes in K562 Cells Reveals a Role for c-Myb as a Master Regulator

• Published in: Genes & cancer 2011-08, Vol.2 (8), p.805-817
• Main Authors: Lorenzo, Petra Isabel, Brendeford, Elen Margrethe, Gilfillan, Siv, Gavrilov, Alexey A, Leedsak, Marit, Razin, Sergey V, Eskeland, Ragnhild, Sæther, Thomas, Gabrielsen, Odd Stokke
• Format: Article
• Language: English
• Subjects: Original
• ISSN: 1947-6019; 1947-6027
• DOI: 10.1177/1947601911428224

The c-Myb transcription factor is an important regulator of hematopoietic cell development. c-Myb is expressed in immature hematopoietic cells and plays a direct role in lineage fate selection, cell cycle progression, and differentiation of myeloid as well as B- and T-lymphoid progenitor cells. As a DNA-binding transcription factor, c-Myb regulates specific gene programs through activation of target genes. Still, our understanding of these programs is incomplete. Here, we report a set of novel c-Myb target genes, identified using a combined approach: specific c-Myb knockdown by 2 different siRNAs and subsequent global expression profiling, combined with the confirmation of direct binding of c-Myb to the target promoters by ChIP assays. The combination of these 2 approaches, as well as additional validation such as cloning and testing the promoters in reporter assays, confirmed that MYADM, LMO2, GATA2, STAT5A, and IKZF1 are target genes of c-Myb. Additional studies, using chromosome conformation capture, demonstrated that c-Myb target genes may directly interact with each other, indicating that these genes may be coordinately regulated. Of the 5 novel target genes identified, 3 are transcription factors, and one is a transcriptional co-regulator, supporting a role of c-Myb as a master regulator controlling the expression of other transcriptional regulators in the hematopoietic system.