title: Analysis of transcriptional regulation of the human miR-17-92 cluster; evidence for involvement of Pim-1.
abstract: The human polycistronic miRNA cluster miR-17-92 is frequently overexpressed in hematopoietic malignancies and cancers. Its transcription is in part controlled by an E2F-regulated host gene promoter. An intronic A/T-rich region directly upstream of the miRNA coding region also contributes to cluster expression. Our deletion analysis of the A/T-rich region revealed a strong dependence on c-Myc binding to the functional E3 site. Yet, constructs lacking the 5'-proximal ~1.3 kb or 3'-distal ~0.1 kb of the 1.5 kb A/T-rich region still retained residual specific promoter activity, suggesting multiple transcription start sites (TSS) in this region. Furthermore, the protooncogenic kinase, Pim-1, its phosphorylation target HP1γ and c-Myc colocalize to the E3 region, as inferred from chromatin immunoprecipitation. Analysis of pri-miR-17-92 expression levels in K562 and HeLa cells revealed that silencing of E2F3, c-Myc or Pim-1 negatively affects cluster expression, with a synergistic effect caused by c-Myc/Pim-1 double knockdown in HeLa cells. Thus, we show, for the first time, that the protooncogene Pim-1 is part of the network that regulates transcription of the human miR-17-92 cluster.
authors.affiliation: Institut für Pharmazeutische Chemie, Philipps-Universität Marburg, 35032 Marburg, Germany. arnold.gruenweller@staff.uni-marburg.de.
authors.forename: Maren
authors.initials: M
authors.lastname: Thomas
authors.forename: Kerstin
authors.initials: K
authors.lastname: Lange-Grünweller
authors.forename: Dorothee
authors.initials: D
authors.lastname: Hartmann
authors.forename: Lara
authors.initials: L
authors.lastname: Golde
authors.forename: Julia
authors.initials: J
authors.lastname: Schlereth
authors.forename: Dennis
authors.initials: D
authors.lastname: Streng
authors.forename: Achim
authors.initials: A
authors.lastname: Aigner
authors.forename: Arnold
authors.initials: A
authors.lastname: Grünweller
authors.forename: Roland K
authors.initials: RK
authors.lastname: Hartmann
mesh_terms: D020856:AT Rich Sequence / Q000235:genetics; D001665:Binding Sites / Q000235:genetics; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D005786:Gene Expression Regulation; D056426:Genetic Loci; D015894:Genome, Human; D006367:HeLa Cells; D006801:Humans; D007438:Introns / Q000235:genetics; D020014:K562 Cells; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding / Q000235:genetics; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism; D051573:Proto-Oncogene Proteins c-pim-1 / Q000378:metabolism*; D062085:RNA, Long Noncoding; D014158:Transcription, Genetic
chemical_list: C518294:CBX3 protein, human; D002868:Chromosomal Proteins, Non-Histone; C568997:MIR17HG, human; D035683:MicroRNAs; D016271:Proto-Oncogene Proteins c-myc; D062085:RNA, Long Noncoding; C496634:PIM1 protein, human; D051573:Proto-Oncogene Proteins c-pim-1