Tumor suppressor activity of KLF6 mediated by downregulation of the PTTG1 oncogene

FEBS Lett. 2010 Mar 5;584(5):1006-10. doi: 10.1016/j.febslet.2010.01.049. Epub 2010 Jan 30.

Abstract

The tumor suppressor Kruppel-like factor 6 (KLF6) is frequently inactivated in hepatocellular carcinoma (HCC). To unearth downstream transcriptional targets of KLF6, cDNA microarray analysis of whole liver was compared between KLF6+/+ and KLF6+/- mice. Pituitary tumor transforming gene 1 (PTTG1), an oncogene, was the most up-regulated transcript in KLF6+/- liver. In human HCCs, KLF6 mRNA was significantly decreased, associated with increased PTTG1. In HepG2, KLF6 transcriptionally repressed PTTG1 by direct promoter interaction. Whereas KLF6 downregulation by siRNA increased HepG2 proliferation, siRNA to PTTG1 was anti-proliferative. PTTG1 downregulation represents a novel tumor suppressor pathway of KLF6.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Carcinoma, Hepatocellular / genetics
  • Carcinoma, Hepatocellular / metabolism
  • Cell Line, Tumor
  • Cell Proliferation
  • Chromatin Immunoprecipitation
  • Humans
  • In Vitro Techniques
  • Kruppel-Like Factor 6
  • Kruppel-Like Transcription Factors / genetics
  • Kruppel-Like Transcription Factors / metabolism*
  • Liver Neoplasms / genetics
  • Liver Neoplasms / metabolism
  • Mice
  • Mice, Mutant Strains
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism*
  • Promoter Regions, Genetic / genetics
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / metabolism*
  • RNA, Small Interfering
  • Reverse Transcriptase Polymerase Chain Reaction
  • Securin

Substances

  • Klf6 protein, mouse
  • Kruppel-Like Factor 6
  • Kruppel-Like Transcription Factors
  • Neoplasm Proteins
  • Proto-Oncogene Proteins
  • RNA, Small Interfering
  • Securin
  • pituitary tumor-transforming protein 1, human