Date : 27/06/2011

Internship proposal for : Master 2

Laboratory
Unité Polarité Cellulaire, Migration et Cancer
Institut Pasteur
25 rue du Dr Roux
75724 Paris cedex 15
Website : http://www.pasteur.fr/ip/easysite/pasteur/fr/recherche/departements-scientifiques/biologie-cellulaire-et-infection/unites-et-groupes/groupe-a-5-ans-polarite-et-migration-cellulaires
Main discipline : Cell Biology
Lab director : Sandrine Etienne-Manneville

Mentor
Sandrine Etienne-Manneville
email : Cet e-mail est protégé contre les robots collecteurs de mails, votre navigateur doit accepter le Javascript pour le voir
phone : +33 1 40 61 39 05

Subjects
1.: cell polarity
2.: mechanotransduction
3.: cytoskeleton

Tools and methodologies
1.: techniques de pointe de microscopie (TIRF, Spinning disc...)
2.: microfabrication (micropatrons, microfluidique, structures 3D...)
3.: micromanipulation (ablation laser, pince magnétique et optique)

Summary of lab's interests

Cell polarity is defined by the ability of a cell to be morphologically, structurally and functionally organized along a polarity axis. Polarity is a critical parameter in most cellular functions such as cell division and cell differentiation. It is also a key step leading to the initiation and the regulation of cell migration. The biological importance of cell polarity is reflected by its crucial role during development and also by the fact that polarity is strongly perturbed in tumors. Our major aim is to decipher the fundamental molecular mechanisms controlling cell polarity. We have tackled this question by studying cell polarity during astrocyte migration. Astrocytes are major glial cells of the central nervous system. Under pathological situations involving inflammation of the cerebral tissue, astrocytes become reactive, polarize and migrate in the direction of the inflammatory site. Astrocytes or their progenitors can give rise to astrocytomas and glioblastomas, which are extremely invasive brain tumors and are associated with a very poor prognosis. The mechanical properties of the cell microenvironment can modulate gene expression and cell polarity to control cell morphology and behaviour. Moreover, alterations the physical properties of the tissue are involved in cancer development. However, the mechanisms responsible for the transduction of mechanical constraints within the cell to control cell polarity and behaviour still remain obscure.

Summary of project

The goal of this project is to study how mechanical constraints can influence cell polarity and to determine the specific role of various cytoskeletal elements in this context. This project relies on three major approaches: 1- Primary culture of normal and tumoral cells. Microfabrication (micropatterning, microfluidics) will be used to generate controled cellular environnement in 2D and 3D. l'utilisation de cultures primaires de cellules normales et tumorales. 2- Application of forces on cells and analysis of cell mechanical responses. The substrate rigidity will be reproducibly and precisely controlled using functionnalized acrylamide-based gells. Cells will be mechanically challenged either indirectly by manipulating the substrates or directly by using magnetic and optical tweezers. Analysis of substrate deformation will allow us to determine the amplitude and localization of forces generated by the cell in response to these stimulations. 3- Analysis of the cytoskeleton function in control of cell polarity. Nucleus, centrosome, Golgi apparatus and cytoskeletal structure will be visualized in live cells using cells expressing GFP tagged proteins. Drug treatments, specific siRNA and laser ablation will be used to determine the role of microfilaments, microtubules and intermediate filaments in mechanotransduction and cell polarity.