C/EBPα inhibits hepatocellular carcinoma by reducing Notch3/Hes1/p27 cascades

Dig Liver Dis. 2013 Oct;45(10):844-51. doi: 10.1016/j.dld.2013.03.013. Epub 2013 Jun 28.

Abstract

Background and aims: CCAAT/enhancer binding protein α is one of the key transcription factors of the hepatocyte nuclear factors family, which plays a critical role in liver cell proliferation and differentiation. However, the role of CCAAT/enhancer binding protein α in hepatocarcinogenesis remains to be defined.

Methods: A recombinant adenovirus carrying the C/EBPα gene was constructed to determine its effect on hepatocarcinogenesis in vitro and in vivo.

Results: We demonstrated that overexpression of CCAAT/enhancer binding protein α inhibited the tumourigenicity of Huh7 cells, re-established the expression of certain liver-specific genes and induced G0/G1 arrest. Overexpression of CCAAT/enhancer binding protein α significantly suppressed the proliferation of primary hepatocarcinogenesis cells and tumour associated fibroblasts in vitro. Additionally, intratumoural injection of adenovirus carrying the C/EBPα reduced the growth of subcutaneous hepatocarcinogenesis xenografts in nude mice. Systemic administration of adenovirus carrying the C/EBPα resulted in the eradication of orthotopic liver hepatocarcinogenesis nodules in nude mice. Further, up-regulation of CCAAT/enhancer binding protein α reduced the expression of Notch3, thereby suppressing Hes1 transactivation activity and leading to decreased p27 expression. Overexpression of Hes1 partially abolished the anti-proliferation effect of CCAAT/enhancer binding protein α on Huh7 cells.

Conclusion: These results suggested that the effect of CCAAT/enhancer binding protein α on hepatocarcinogenesis is partially through by reducing Notch3/Hes1/p27 cascades and CCAAT/enhancer binding protein α may possess a novel therapeutic potential for human hepatocarcinogenesis.

Keywords: C/EBPα; Hepatocellular carcinoma; Hes1; Notch3.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoviridae
  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • CCAAT-Enhancer-Binding Protein-alpha / genetics
  • CCAAT-Enhancer-Binding Protein-alpha / metabolism*
  • Carcinoma, Hepatocellular / genetics*
  • Carcinoma, Hepatocellular / metabolism*
  • Carcinoma, Hepatocellular / pathology
  • Cell Line, Tumor
  • Cell Proliferation
  • Cell Transformation, Neoplastic / genetics
  • Cell Transformation, Neoplastic / metabolism*
  • G1 Phase Cell Cycle Checkpoints
  • Gene Expression Regulation, Neoplastic*
  • Genetic Vectors
  • Homeodomain Proteins / metabolism
  • Humans
  • Liver Neoplasms / genetics*
  • Liver Neoplasms / metabolism*
  • Liver Neoplasms / pathology
  • Mice
  • Mice, Inbred BALB C
  • Neoplasm Transplantation
  • Proliferating Cell Nuclear Antigen / metabolism
  • Receptor, Notch3
  • Receptors, Notch / metabolism
  • Signal Transduction
  • Transcription Factor HES-1
  • Transfection

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • CCAAT-Enhancer-Binding Protein-alpha
  • Homeodomain Proteins
  • NOTCH3 protein, human
  • Proliferating Cell Nuclear Antigen
  • Receptor, Notch3
  • Receptors, Notch
  • Transcription Factor HES-1
  • p27 antigen
  • HES1 protein, human