E-Cadherin Expression in GBM 50. du Plessis DG, Rutherfoord GS, Joyce KA, Walker C (2004) Phenotypic and genotypic characterization of glioblastoma multiforme with epithelial differen- tiation and adenoid formations. Clin Neuropathol 23: 141–148. 51. Ozolek JA, Finkelstein SD, Couce ME (2004) Gliosarcoma with epithelial differentiation: immunohistochemical and molecular characterization. A case report and review of the literature. Mod Pathol 17: 739–745. 52. Phillips HS, Kharbanda S, Chen R, Forrest WF, Soriano RH, et al. (2006) Molecular subclasses of high-grade glioma predict prognosis, delineate a pattern of disease progression, and resemble stages in neurogenesis. Cancer Cell 9: 157–173. 53. Perez TD, Tamada M, Sheetz MP, Nelson WJ (2008) Immediate-early signaling induced by E-cadherin engagement and adhesion. J Biol Chem 283: 5014–5022. 54. Yamada S, Nelson WJ (2007) Localized zones of Rho and Rac activities drive initiation and expansion of epithelial cell-cell adhesion. J Cell Biol 178: 517–527. 55. Friedl P, Wolf K (2003) Tumour-cell invasion and migration: diversity and escape mechanisms. Nat Rev Cancer 3: 362–374. 56. Sarkaria JN, Carlson BL, Schroeder MA, Grogan P, Brown PD, et al. (2006) Use of an orthotopic xenograft model for assessing the effect of epidermal growth factor receptor amplification on glioblastoma radiation response. Clin Cancer Res 12: 2264–2271. 57. Sarkaria JN, Yang L, Grogan PT, Kitange GJ, Carlson BL, et al. (2007) Identification of molecular characteristics correlated with glioblastoma sensitivity to EGFR kinase inhibition through use of an intracranial xenograft test panel. Mol Cancer Ther 6: 1167–1174. 58. Yang L, Clarke MJ, Carlson BL, Mladek AC, Schroeder MA, et al. (2008) PTEN loss does not predict for response to RAD001 (Everolimus) in a glioblastoma orthotopic xenograft test panel. Clin Cancer Res 14: 3993–4001. 59. Bible KC, Boerner SA, Kaufmann SH (1999) A one-step method for protein estimation in biological samples: nitration of tyrosine in nitric acid. Anal Biochem 267: 217–221. 60. Livak KJ, Schmittgen TD (2001) Analysis of relative gene expression data using real-time quantitative PCR and the 2(-Delta Delta C(T)) Method. Methods 25: 402–408. PLoS ONE | www.plosone.org 12 October 2010 | Volume 5 | Issue 10 | e13665