Sandrine Etienne-Manneville (website)
The goal of this project is to determine the role of phosphoinositides and regulatory enzymes (PI3K and PTEN) in the front-to-rear polarization during collective migration of normal and tumorous cells.
The localization of PIPs and the distribution of PTEN and PI3K will be investigated in vitro and in vivo. In vitro collective migration will be analysed using glial cells migrating in a wound-healing assay. This assay has been thoroughly characterized and successfully used in the lab. The distribution of phosphoinositides will be analysed in these various conditions. Preliminary results obtained in vitro indicate that the distribution of PIP3 and PIP2 is strongly polarized, and that PIP2 synthesis by the lipid phosphatase PTEN was required for directed migration. The role of the polarized distribution of phosphoinositides in polarity signalling will then be determined. PTEN and/or PI3K activity will be inhibited using siRNA or pharmacological inhibitors. Light inducible targeting systems will be used to induce localized changes in phosphoinositide concentrations (collaboration with the Arkowitz group ). The impact of these modifications on integrin and cadherin-mediated polarity signals will be determined. The influence of phosphoinositide distribution on the polarized recycling of integrins and cadherins will be determined by video microscopy. The consequences of phosphoinositide misregulation on polarity signalling will be determined, focussing more particularly on the polarized recruitment of PAR proteins.
Phosphatidyl inositol signalling is perturbed in a vast majority of glioblastomas, tumors that derive from glial cells or their precursors, such as astrocytes. In parallel, the impact of phosphatidyl signalling on the migratory properties of primary astrocytes, neural precursors and glioblastoma cells injected in the zebrafish brain will be determine. How changes in phosphatidyl signalling promotes cell invasion and favors specific route of migration in the brain will be investigated.
This project will broaden our understanding of the role of phosphoinositides in collective directed migration and invasion. and should lead to a better understanding of the consequences of alterations of PTEN or PI3K signalling in cancer cell invasion.
- Peglion F, Llense F, Etienne-Manneville S. Adherens junction treadmilling during collective migration. Nat Cell Biol. 2014 Jul;16(7):639–51.
- Hopkins BD, Hodakoski C, Barrows D, Mense SM, Parsons RE. PTEN function: the long and the short of it. Trends Biochem Sci. 2014 Apr;39(4):183–90.
- Höland K, Salm F, Arcaro A. The phosphoinositide 3-kinase signaling pathway as a therapeutic target in grade IV brain tumors. Curr Cancer Drug Targets. 2011 Oct;11(8):894–918.
- Lima-Fernandes E, Enslen H, Camand E, Kotelevets L, Boularan C, Achour L, et al. Distinct functional outputs of PTEN signalling are controlled by dynamic association with β-arrestins. EMBO J. 2011 Jul 6;30(13):2557–68.
- Raftopoulou M, Etienne-Manneville S, Self A, Nicholls S, Hall A. Regulation of cell migration by the C2 domain of the tumor suppressor PTEN. Science. 2004 Feb 20;303(5661):1179–81.