H-ferritin-regulated microRNAs modulate gene expression in K562 cells

PLoS One. 2015 Mar 27;10(3):e0122105. doi: 10.1371/journal.pone.0122105. eCollection 2015.

Abstract

In a previous study, we showed that the silencing of the heavy subunit (FHC) offerritin, the central iron storage molecule in the cell, is accompanied by a modification in global gene expression. In this work, we explored whether different FHC amounts might modulate miRNA expression levels in K562 cells and studied the impact of miRNAs in gene expression profile modifications. To this aim, we performed a miRNA-mRNA integrative analysis in K562 silenced for FHC (K562shFHC) comparing it with K562 transduced with scrambled RNA (K562shRNA). Four miRNAs, namely hsa-let-7g, hsa-let-7f, hsa-let-7i and hsa-miR-125b, were significantly up-regulated in silenced cells. The remarkable down-regulation of these miRNAs, following FHC expression rescue, supports a specific relation between FHC silencing and miRNA-modulation. The integration of target predictions with miRNA and gene expression profiles led to the identification of a regulatory network which includes the miRNAs up-regulated by FHC silencing, as well as91 down-regulated putative target genes. These genes were further classified in 9 networks; the highest scoring network, "Cell Death and Survival, Hematological System Development and Function, Hematopoiesis", is composed by 18 focus molecules including RAF1 and ERK1/2. We confirmed that, following FHC silencing, ERK1/2 phosphorylation is severely impaired and that RAF1 mRNA is significantly down-regulated. Taken all together, our data indicate that, in our experimental model, FHC silencing may affect RAF1/pERK1/2 levels through the modulation of a specific set of miRNAs and add new insights in to the relationship among iron homeostasis and miRNAs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoferritins / genetics*
  • Apoferritins / metabolism
  • Cell Line, Tumor
  • Gene Regulatory Networks*
  • Humans
  • MAP Kinase Signaling System
  • MicroRNAs / genetics*
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • raf Kinases / genetics
  • raf Kinases / metabolism

Substances

  • MicroRNAs
  • mirnlet7 microRNA, human
  • Apoferritins
  • raf Kinases
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3

Grants and funding

This work received support from Italian Ministry of Education, University and Research (PON01_02834 – Prometeo grant to GC; PRIN 2010–11, project number 2010NYKNS7 to SB; Fondazione Cariparo (Excellence Projects 2011–2012) to SB). This study was supported by the Italian Ministry of Education, University and Research (PON01_02834 – Prometeo grant to GC; PRIN 2010–11, project number 2010NYKNS7 to SB) and by Fondazione Cariparo (Excellence Projects 2011–2012) to SB. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.