CDKN1C/P57 is regulated by the Notch target gene Hes1 and induces senescence in human hepatocellular carcinoma

Am J Pathol. 2012 Aug;181(2):413-22. doi: 10.1016/j.ajpath.2012.04.019. Epub 2012 Jun 15.


CDKN1C/P57 is a cyclin-dependent kinase inhibitor implicated in different human cancers, including hepatocellular carcinoma (HCC); however, little is known regarding the role of CDKN1C/P57 and its regulation in HCC. In this study, we show that the down-regulation of Notch1 and Notch3 in two HCC cell lines resulted in Hes1 down-regulation, CDKN1C/P57 up-regulation, and reduced cell growth. In line with these data, we report that CDKN1C/P57 is a target of transcriptional repression by the Notch effector, Hes1. We found that the up-regulation of CDKN1C/P57 by cDNA transfection decreased tumor growth, as determined by growth curve, flow cytometry analysis, and cyclin D1 down-regulation, without affecting the apoptosis machinery. Indeed, the expression of Bax, Noxa, PUMA, BNIP(3), and cleaved caspase-3 was not affected by CDKN1C/P57 induction. Morphologically CDKN1C/p57-induced HCC cells became flat and lengthened in shape, accumulated the senescence-associated β-galactosidase marker, and increased P16 protein expression. Evaluation of senescence in cells depleted both for Hes1 and CDKN1C/P57 revealed that the senescent state really depends on the accumulation of CDKN1C/p57. Finally, we validated our in vitro results in primary HCCs, showing that Hes1 protein expression inversely correlates with CDKN1C/P57 mRNA levels. In addition, reduced Hes1 protein expression is accompanied by a shorter time to recurrence after curative resection, suggesting that Hes1 may represent a biomarker for prediction of patients with poor prognosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Apoptosis / genetics
  • Basic Helix-Loop-Helix Transcription Factors / genetics*
  • Carcinoma, Hepatocellular / genetics*
  • Carcinoma, Hepatocellular / pathology*
  • Cell Cycle / genetics
  • Cell Line, Tumor
  • Cell Proliferation
  • Cellular Senescence / genetics*
  • Chromatin Immunoprecipitation
  • Cyclin-Dependent Kinase Inhibitor p57 / genetics*
  • Cyclin-Dependent Kinase Inhibitor p57 / metabolism
  • Female
  • Fluorescent Antibody Technique
  • Gene Expression Regulation, Neoplastic
  • Gene Silencing
  • Homeodomain Proteins / genetics*
  • Humans
  • Liver Neoplasms / genetics
  • Liver Neoplasms / pathology
  • Male
  • Middle Aged
  • Receptor, Notch1 / metabolism*
  • Receptor, Notch3
  • Receptors, Notch / metabolism*
  • Recurrence
  • Signal Transduction
  • Time Factors
  • Transcription Factor HES-1


  • Basic Helix-Loop-Helix Transcription Factors
  • CDKN1C protein, human
  • Cyclin-Dependent Kinase Inhibitor p57
  • Homeodomain Proteins
  • NOTCH1 protein, human
  • NOTCH3 protein, human
  • Receptor, Notch1
  • Receptor, Notch3
  • Receptors, Notch
  • Transcription Factor HES-1
  • HES1 protein, human