Rac1-dependent lamellipodial motility in prostate cancer PC-3 cells revealed by optogenetic control of Rac1 activity

PLoS One. 2014 May 21;9(5):e97749. doi: 10.1371/journal.pone.0097749. eCollection 2014.

Abstract

The lamellipodium, an essential structure for cell migration, plays an important role in the invasion and metastasis of cancer cells. Although Rac1 recognized as a key player in the formation of lamellipodia, the molecular mechanisms underlying lamellipodial motility are not fully understood. Optogenetic technology enabled us to spatiotemporally control the activity of photoactivatable Rac1 (PA-Rac1) in living cells. Using this system, we revealed the role of phosphatidylinositol 3-kinase (PI3K) in Rac1-dependent lamellipodial motility in PC-3 prostate cancer cells. Through local blue laser irradiation of PA-Rac1-expressing cells, lamellipodial motility was reversibly induced. First, outward extension of a lamellipodium parallel to the substratum was observed. The extended lamellipodium then showed ruffling activity at the periphery. Notably, PI(3,4,5)P3 and WAVE2 were localized in the extending lamellipodium in a PI3K-dependent manner. We confirmed that the inhibition of PI3K activity greatly suppressed lamellipodial extension, while the ruffling activity was less affected. These results suggest that Rac1-induced lamellipodial motility consists of two distinct activities, PI3K-dependent outward extension and PI3K-independent ruffling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Enzyme Inhibitors / pharmacology
  • Humans
  • Male
  • Movement*
  • Optogenetics*
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphoinositide-3 Kinase Inhibitors
  • Prostatic Neoplasms / pathology*
  • Protein Transport
  • Pseudopodia / metabolism*
  • rac1 GTP-Binding Protein / metabolism*

Substances

  • Enzyme Inhibitors
  • Phosphoinositide-3 Kinase Inhibitors
  • rac1 GTP-Binding Protein

Grant support

This study was supported by Japan Society for the Promotion of Science (JSPS) KAKENHI (http://www.jsps.go.jp/english/e-grants/index.html) 25861427 to TK; 24659087 and 23390039 to NA; 26860136 and 24890154 to KK; 25860142 to YE; 24390369 to YK. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.