C/EBPδ gene targets in human keratinocytes

PLoS One. 2010 Nov 2;5(11):e13789. doi: 10.1371/journal.pone.0013789.

Abstract

C/EBPs are a family of B-Zip transcription factors--TFs--involved in the regulation of differentiation in several tissues. The two most studied members--C/EBPα and C/EBPβ--play important roles in skin homeostasis and their ablation reveals cells with stem cells signatures. Much less is known about C/EBPδ which is highly expressed in the granular layer of interfollicular epidermis and is a direct target of p63, the master regular of multilayered epithelia. We identified C/EBPδ target genes in human primary keratinocytes by ChIP on chip and profiling of cells functionally inactivated with siRNA. Categorization suggests a role in differentiation and control of cell-cycle, particularly of G2/M genes. Among positively controlled targets are numerous genes involved in barrier function. Functional inactivation of C/EBPδ as well as overexpressions of two TF targets--MafB and SOX2--affect expression of markers of keratinocyte differentiation. We performed IHC on skin tumor tissue arrays: expression of C/EBPδ is lost in Basal Cell Carcinomas, but a majority of Squamous Cell Carcinomas showed elevated levels of the protein. Our data indicate that C/EBPδ plays a role in late stages of keratinocyte differentiation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • CCAAT-Enhancer-Binding Protein-delta / genetics*
  • CCAAT-Enhancer-Binding Protein-delta / metabolism
  • Cell Differentiation
  • Cells, Cultured
  • Gene Expression Profiling*
  • Humans
  • Immunohistochemistry
  • Keratinocytes / cytology
  • Keratinocytes / metabolism*
  • MafB Transcription Factor / genetics
  • MafB Transcription Factor / metabolism
  • Oligonucleotide Array Sequence Analysis
  • Reverse Transcriptase Polymerase Chain Reaction
  • SOXB1 Transcription Factors / genetics
  • SOXB1 Transcription Factors / metabolism
  • Skin / metabolism
  • Skin / pathology
  • Skin Neoplasms / genetics
  • Skin Neoplasms / metabolism
  • Skin Neoplasms / pathology
  • Tissue Array Analysis

Substances

  • MAFB protein, human
  • MafB Transcription Factor
  • SOX2 protein, human
  • SOXB1 Transcription Factors
  • CCAAT-Enhancer-Binding Protein-delta