title: Deregulated KLF4 Expression in Myeloid Leukemias Alters Cell Proliferation and Differentiation through MicroRNA and Gene Targets.
abstract: Acute myeloid leukemia (AML) is characterized by increased proliferation and blocked differentiation of hematopoietic progenitors mediated, in part, by altered myeloid transcription factor expression. Decreased Krüppel-like factor 4 (KLF4) expression has been observed in AML, but how decreased KLF4 contributes to AML pathogenesis is largely unknown. We demonstrate decreased KLF4 expression in AML patient samples with various cytogenetic aberrations, confirm that KLF4 overexpression promotes myeloid differentiation and inhibits cell proliferation in AML cell lines, and identify new targets of KLF4. We have demonstrated that microRNA 150 (miR-150) expression is decreased in AML and that reintroducing miR-150 expression induces myeloid differentiation and inhibits proliferation of AML cells. We show that KLF family DNA binding sites are necessary for miR-150 promoter activity and that KLF2 or KLF4 overexpression induces miR-150 expression. miR-150 silencing, alone or in combination with silencing of CDKN1A, a well-described KLF4 target, did not fully reverse KLF4-mediated effects. Gene expression profiling and validation identified putative KLF4-regulated genes, including decreased MYC and downstream MYC-regulated gene expression in KLF4-overexpressing cells. Our findings indicate that decreased KLF4 expression mediates antileukemic effects through regulation of gene and microRNA networks, containing miR-150, CDKN1A, and MYC, and provide mechanistic support for therapeutic strategies increasing KLF4 expression.
authors.affiliation: Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA.
authors.forename: Valerie A
authors.initials: VA
authors.lastname: Morris
authors.affiliation: Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA.
authors.forename: Carrie L
authors.initials: CL
authors.lastname: Cummings
authors.affiliation: Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA.
authors.forename: Brendan
authors.initials: B
authors.lastname: Korb
authors.affiliation: Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA.
authors.forename: Sean
authors.initials: S
authors.lastname: Boaglio
authors.affiliation: Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA Division of Hematology, Department of Medicine, University of Washington, Seattle, Washington, USA voehler@u.washington.edu.
authors.forename: Vivian G
authors.initials: VG
authors.lastname: Oehler
mesh_terms: D001483:Base Sequence; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics; D015973:Gene Expression Regulation, Leukemic; D006801:Humans; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors / Q000235:genetics*; D007951:Leukemia, Myeloid / Q000235:genetics* / Q000473:pathology; D035683:MicroRNAs / Q000235:genetics*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic
chemical_list: D050759:Cyclin-Dependent Kinase Inhibitor p21; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; D035683:MicroRNAs; C096161:KLF2 protein, human; C000715467:KLF4 protein, human; C533097:MIR150, human