title: Clustered localization of EGFRvIII in glioblastoma cells as detected by high precision localization microscopy.
abstract: For receptor tyrosine kinases supramolecular organization on the cell membrane is critical for their function. Super-resolution fluorescence microscopy techniques have offered new opportunities for the analysis of single receptor localization. Here, we analysed the cluster formation of the epidermal growth factor receptor variant III (EGFRvIII), a deletion variant which is expressed in glioblastoma. The constitutively activated variant EGFRvIII is expressed in cells with an egfr gene amplification and is thought to enhance the tumorigenic potential especially of glioblastoma cells. Due to the lack of an adequate model system, it is still unclear how endogenous EGFRvIII expression alters cellular signalling and if it is organized in clusters like the wild type receptor. We have recently described the establishment of two pairs of iso-genetic cell lines (BS153 and DKMG), displaying endogenous EGFRvIII expression or not. Using these cell lines we investigated single receptor localization of EGFRvIII by high precision localization microscopy. Cluster analysis revealed that EGFRvIII is present in clusters on the surface of the cells, with about 60% or even more receptor molecules being assembled in clusters of approximately 100 nm in diameter whereby the cluster definition was iteratively determined. The signal to signal distance may indicate dimer formation while signal quantification indicates 1 × 106-5 × 106EGFRvIII molecules per cell. Altogether, these data give unique insights into the membrane surface localization of EGFRvIII in glioblastoma cells. These insights will help to unveil the function of this tumour associated receptor variant which might lead to a better understanding of glioblastoma and therefore could lead to improved therapy approaches.
authors.affiliation: Kirchhoff-Institute for Physics, University of Heidelberg, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany. hausmann@kip.uni-heidelberg.de.
authors.forename: Philip S
authors.initials: PS
authors.lastname: Boyd
authors.forename: Nina
authors.initials: N
authors.lastname: Struve
authors.forename: Margund
authors.initials: M
authors.lastname: Bach
authors.forename: Jan Philipp
authors.initials: JP
authors.lastname: Eberle
authors.forename: Martin
authors.initials: M
authors.lastname: Gote
authors.forename: Florian
authors.initials: F
authors.lastname: Schock
authors.forename: Christoph
authors.initials: C
authors.lastname: Cremer
authors.forename: Malte
authors.initials: M
authors.lastname: Kriegs
authors.forename: Michael
authors.initials: M
authors.lastname: Hausmann
mesh_terms: D000818:Animals; D001932:Brain Neoplasms / Q000378:metabolism*; D045744:Cell Line, Tumor; D066246:ErbB Receptors / Q000032:analysis*; D005909:Glioblastoma / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008853:Microscopy
chemical_list: D066246:ErbB Receptors