title: Global gene expression analyses of hematopoietic stem cell-like cell lines with inducible Lhx2 expression.
abstract: BACKGROUND
  Expression of the LIM-homeobox gene Lhx2 in murine hematopoietic cells allows for the generation of hematopoietic stem cell (HSC)-like cell lines. To address the molecular basis of Lhx2 function, we generated HSC-like cell lines where Lhx2 expression is regulated by a tet-on system and hence dependent on the presence of doxycyclin (dox). These cell lines efficiently down-regulate Lhx2 expression upon dox withdrawal leading to a rapid differentiation into various myeloid cell types.
  
  
  RESULTS
  Global gene expression of these cell lines cultured in dox was compared to different time points after dox withdrawal using microarray technology. We identified 267 differentially expressed genes. The majority of the genes overlapping with HSC-specific databases were those down-regulated after turning off Lhx2 expression and a majority of the genes overlapping with those defined as late progenitor-specific genes were the up-regulated genes, suggesting that these cell lines represent a relevant model system for normal HSCs also at the level of global gene expression. Moreover, in situ hybridisations of several genes down-regulated after dox withdrawal showed overlapping expression patterns with Lhx2 in various tissues during embryonic development.
  
  
  CONCLUSIONS
  Global gene expression analysis of HSC-like cell lines with inducible Lhx2 expression has identified genes putatively linked to self-renewal/differentiation of HSCs, and function of Lhx2 in organ development and stem/progenitor cells of non-hematopoietic origin.
authors.affiliation: Umeå Center for Molecular Medicin, Umeå Universitet, 90187 Umeå, Sweden. karin.richter@ucmm.umu.se
authors.forename: Karin
authors.initials: K
authors.lastname: Richter
authors.forename: Valtteri
authors.initials: V
authors.lastname: Wirta
authors.forename: Lina
authors.initials: L
authors.lastname: Dahl
authors.forename: Sara
authors.initials: S
authors.lastname: Bruce
authors.forename: Joakim
authors.initials: J
authors.lastname: Lundeberg
authors.forename: Leif
authors.initials: L
authors.lastname: Carlsson
authors.forename: Cecilia
authors.initials: C
authors.lastname: Williams
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D015536:Down-Regulation; D004318:Doxycycline / Q000378:metabolism / Q000494:pharmacology; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism; D005786:Gene Expression Regulation; D006412:Hematopoietic Stem Cells / Q000187:drug effects / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D017403:In Situ Hybridization; D060850:LIM-Homeodomain Proteins; D051379:Mice; D008954:Models, Biological; D020411:Oligonucleotide Array Sequence Analysis; D013752:Tetracycline / Q000378:metabolism / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; C489784:Lhx2 protein, mouse; D014157:Transcription Factors; D013752:Tetracycline; D004318:Doxycycline