Targeting endogenously active Ras by MSOR impacts on cell survival. (A) Confocal images of Cos-7 cells transiently expressing EGFP or mono-, di- or trivalent wild-type RBD probes. Scale bar 10 μm. (B) The fraction of dead cells among E1-, E1-R1- or E1-R3-expressing cells was determined by measuring Annexin V-positive cells using FACS and normalized to the EGFP-expressing condition. Data represent three independent experiments. (C) Caspase gene expression in COS-7 cells, transiently transfected with an expression construct for K-RasG12V along with E1 or E1-R3 was analyzed on a custom oligonucleotide microarray. Signals were assessed densitometrically and normalized to the E1 expression level. See Material and methods for a more detailed description. Data are derived from three independent experiments. See Material and methods for a more detailed description.