Kruppel-like factor-9 (KLF9) inhibits glioblastoma stemness through global transcription repression and integrin α6 inhibition

J Biol Chem. 2014 Nov 21;289(47):32742-56. doi: 10.1074/jbc.M114.588988. Epub 2014 Oct 6.

Abstract

It is increasingly important to understand the molecular basis for the plasticity of neoplastic cells and their capacity to transition between differentiated and stemlike phenotypes. Kruppel-like factor-9 (KLF9), a member of the large KLF transcription factor family, has emerged as a regulator of oncogenesis, cell differentiation, and neural development; however, the molecular basis for the diverse contextual functions of KLF9 remains unclear. This study focused on the functions of KLF9 in human glioblastoma stemlike cells. We established for the first time a genome-wide map of KLF9-regulated targets in human glioblastoma stemlike cells and show that KLF9 functions as a transcriptional repressor and thereby regulates multiple signaling pathways involved in oncogenesis and stem cell regulation. A detailed analysis of one such pathway, integrin signaling, showed that the capacity of KLF9 to inhibit glioblastoma cell stemness and tumorigenicity requires ITGA6 repression. These findings enhance our understanding of the transcriptional networks underlying cancer cell stemness and differentiation and identify KLF9-regulated molecular targets applicable to cancer therapeutics.

Keywords: Cancer Stem Cells; ChIP-Sequencing (ChIP-Seq); Glioblastoma; Kruppel-like Factor (KLF); Transcription Repressor.

Publication types

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

MeSH terms

  • Animals
  • Antibiotics, Antineoplastic / pharmacology
  • Blotting, Western
  • Cell Differentiation / drug effects
  • Cell Differentiation / genetics*
  • Cell Line, Tumor
  • Doxorubicin / pharmacology
  • Gene Expression Regulation, Neoplastic*
  • Glioblastoma / genetics*
  • Glioblastoma / metabolism
  • Glioblastoma / pathology
  • Humans
  • Integrin alpha6 / genetics*
  • Integrin alpha6 / metabolism
  • Kruppel-Like Transcription Factors / genetics*
  • Kruppel-Like Transcription Factors / metabolism
  • Mice, SCID
  • Promoter Regions, Genetic / genetics
  • Protein Binding
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transplantation, Heterologous
  • Tumor Burden / genetics

Substances

  • Antibiotics, Antineoplastic
  • Integrin alpha6
  • KLF9 protein, human
  • Kruppel-Like Transcription Factors
  • Doxorubicin

Associated data

  • GEO/GSE62211
  • GEO/GSE62212