title: NDRG2 Promotes GATA-1 Expression through Regulation of the JAK2/STAT Pathway in PMA-stimulated U937 Cells.
abstract: BACKGROUND
  N-myc downstream-regulated gene 2 (NDRG2), a member of a newly described family of differentiation-related genes, has been characterized as a regulator of dendritic cells. However, the role of NDRG2 on the expression and activation of transcription factors in blood cells remains poorly understood. In this study, we investigated the effects of NDRG2 overexpression on GATA-1 expression in PMA-stimulated U937 cells.
  
  
  METHODS
  We generated NDRG2-overexpressing U937 cell line (U937-NDRG2) and treated the cells with PMA to investigate the role of NDRG2 on GATA-1 expression.
  
  
  RESULTS
  NDRG2 overexpression in U937 cells significantly induced GATA-1 expression in response to PMA stimulation. Interestingly, JAK2/STAT and BMP-4/Smad pathways associated with the induction of GATA-1 were activated in PMA-stimulated U937-NDRG2 cells. We found that the inhibition of JAK2 activation, but not of BMP-4/Smad signaling, can elicit a decrease of PMA-induced GATA-1 expression in U937-NDRG2 cells.
  
  
  CONCLUSIONS
  The results reveal that NDRG2 promotes the expression of GATA-1 through activation of the JAK2/STAT pathway, but not through the regulation of the BMP-4/Smad pathway in U937 cells. Our findings further suggest that NDRG2 may play a role as a regulator of erythrocyte and megakaryocyte differentiation during hematopoiesis.
authors.affiliation: Department of Biological Science and the Research Center for Women's Disease, Sookmyung Women's University, Seoul 140-742, Korea.
authors.forename: Kyeongah
authors.initials: K
authors.lastname: Kang
authors.forename: Hyeyoun
authors.initials: H
authors.lastname: Jung
authors.forename: Sorim
authors.initials: S
authors.lastname: Nam
authors.forename: Jong-Seok
authors.initials: JS
authors.lastname: Lim