ROCK Inhibition Facilitates In Vitro Expansion of Glioblastoma Stem-Like Cells

PLoS One. 2015 Jul 13;10(7):e0132823. doi: 10.1371/journal.pone.0132823. eCollection 2015.

Abstract

Due to their stem-like characteristics and their resistance to existing chemo- and radiation therapies, there is a growing appreciation that cancer stem cells (CSCs) are the root cause behind cancer metastasis and recurrence. However, these cells represent a small subpopulation of cancer cells and are difficult to propagate in vitro. Glioblastoma is an extremely deadly form of brain cancer that is hypothesized to have a subpopulation of CSCs called glioblastoma stem cells (GSCs; also called brain tumor initiating cells, BTICs). We propose the use of selective Rho-kinase (ROCK) inhibitors, Y-27632 and fasudil, to promote GSC/BTIC-like cell survival and propagation in vitro. ROCK inhibitors have been implicated in suppressing apoptosis, and it was hypothesized that they would increase the number of GSC/BTIC-like cells grown in vitro and improve cloning efficiencies. Indeed, our data demonstrate that transient and continuous supplementation of non-toxic concentrations of Y-27632 and fasudil inhibited apoptosis, enhanced the cells' ability to form spheres, and increased stem cell marker expressing GSC/BTIC-like cell subpopulation. Our data indicated that pharmacological and genetic (siRNA) inhibitions of the ROCK pathway facilitates in vitro expansion of GSC/BTIC-like cells. Thus, ROCK pathway inhibition shows promise for future optimization of CSC culture media.

Publication types

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

MeSH terms

  • Apoptosis / drug effects
  • Brain Neoplasms / pathology*
  • Cell Line, Tumor
  • Glioblastoma / pathology*
  • Humans
  • In Vitro Techniques
  • Neoplastic Stem Cells / pathology*
  • Protein Kinase Inhibitors / pharmacology
  • rho-Associated Kinases / antagonists & inhibitors*

Substances

  • Protein Kinase Inhibitors
  • rho-Associated Kinases