Group I PAK inhibitor IPA-3 induces cell death and affects cell adhesivity to fibronectin in human hematopoietic cells

PLoS One. 2014 Mar 24;9(3):e92560. doi: 10.1371/journal.pone.0092560. eCollection 2014.

Abstract

P21-activated kinases (PAKs) are involved in the regulation of multiple processes including cell proliferation, adhesion and migration. However, the current knowledge about their function is mainly based on results obtained in adherent cell types. We investigated the effect of group I PAK inhibition using the compound IPA-3 in a variety of human leukemic cell lines (JURL-MK1, MOLM-7, K562, CML-T1, HL-60, Karpas-299, Jurkat, HEL) as well as in primary blood cells. IPA-3 induced cell death with EC50 ranging from 5 to more than 20 μM. Similar range was found for IPA-3-mediated dephosphorylation of a known PAK downstream effector, cofilin. The cell death was associated with caspase-3 activation, PARP cleavage and apoptotic DNA fragmentation. In parallel, 20 μM IPA-3 treatment induced rapid and marked decrease of the cell adhesivity to fibronectin. Per contra, partial reduction of PAK activity using lower dose IPA-3 or siRNA resulted in a slight increase in the cell adhesivity. The changes in the cell adhesivity were also studied using real-time microimpedance measurement and by interference reflection microscopy. Significant differences in the intracellular IPA-3 level among various cell lines were observed indicating that an active mechanism is involved in IPA-3 transport.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Depolymerizing Factors / chemistry
  • Actin Depolymerizing Factors / metabolism
  • Apoptosis / drug effects*
  • Blood Cells / cytology*
  • Blood Cells / drug effects*
  • Cell Adhesion / drug effects
  • Cell Proliferation / drug effects
  • Disulfides / metabolism
  • Disulfides / pharmacology*
  • Fibronectins / metabolism*
  • Gene Expression Regulation / drug effects
  • Gene Silencing
  • Hematopoiesis / drug effects
  • Humans
  • Intracellular Space / drug effects
  • Intracellular Space / metabolism
  • Leukemia / pathology
  • Lymphoma / pathology
  • Naphthols / metabolism
  • Naphthols / pharmacology*
  • Phosphorylation / drug effects
  • Protein Kinase Inhibitors / metabolism
  • Protein Kinase Inhibitors / pharmacology*
  • RNA, Small Interfering / genetics
  • Serine / metabolism
  • p21-Activated Kinases / antagonists & inhibitors*
  • p21-Activated Kinases / deficiency
  • p21-Activated Kinases / genetics

Substances

  • Actin Depolymerizing Factors
  • Disulfides
  • Fibronectins
  • IPA-3 compound
  • Naphthols
  • Protein Kinase Inhibitors
  • RNA, Small Interfering
  • Serine
  • p21-Activated Kinases

Grants and funding

The work was supported by the Ministry of Health of the Czech Republic (Project for conceptual development of research organization No 00023736) and by European Union (grants ERDF OPPK CZ.2.16/3.1.00/24001 and CZ.2.16/3.1.00/28007). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.