Mutant p53 counteracts IFNβ by SOCS1-mediated attenuation of STAT1 phosphorylation.
(A) Cells were treated with IFNβ for 16 h, fixed and sorted by an “Image stream” FACS. The upper panel depicts representative images from each condition and the graph represents the mean pixel intensity of STAT1 positive cells for the entire population. (B) Same as in A, here the graph shows the similarity between p-STAT and DAPI staining, thereby quantifying both the expression and localization of pSTAT1. (C) Cells were treated with IFNβ for the designated durations, shown is a graph depicting nuclear p-STAT1. (D) The cells were also collected for RNA analysis and a QRT-PCR for SOCS1 expression was performed. (E) H1299175 cells were introduced with RNAi against LacZ as a control or against SOCS1. p = 0.002 (F) Cells were then treated with IFNβ for 24 h. Shown is a QRT-PCR analysis of MX1 expression. p<0.05. (G) Cells were seeded in trans-wells in serum-free media and treated with IFNβ for 24 h. Migrating cells were collected and counted.