E-GEOD-41477 - Mutant p53 attenuates the anti-tumorigenic activity of fibroblasts secreted interferon (IFN) beta
Released on 10 October 2013, last updated on 2 June 2014
Mutations in the p53 tumor suppressor protein are highly frequent in tumors and often endow cells with tumorigenic capacities. We sought to examine a possible role for mutant p53 in the cross-talk between cancer cells and their surrounding stroma, which is a crucial factor affecting tumor outcome. Here we present a novel model which enables to individually monitor the response of cancer cells and stromal cells (fibroblasts) to co-culturing. We found that fibroblasts elicit the interferon beta (IFNβ) pathway when in contact with cancer cells, thereby inhibiting their migration. Mutant p53 in the tumor was able to alleviate this response via SOCS1 mediated inhibition of STAT1 phosphorylation. IFNβ on the other hand, reduced mutant p53 RNA levels by restricting its RNA stabilizer, WIG1. These data underscore mutant p53 oncogenic properties in the context of the tumor microenvironment and suggest that mutant p53 positive cancer patients might benefit from IFNβ treatment. As we planned to investigate the effect of mutant p53 we chose to work with lung cancer cells (H1299) which are null for p53 expression and introduce them with two p53 ‘hotsopt’ mutations residing within the DNA binding domain namely R175H and R248Q (H1299175 and H1299248 respectively, Figure 1A and B). The cells were then labeled with a red fluorescent protein (dsRed), while lung CAFs (HK3-T) were labeled with a green fluorescent protein (GFP). The labeled populations were co-cultivated for 24 hours and separated by Fluorescence Associated Cell Sorting (FACS) based on their specific fluorescent marker. RNA was extracted and samples were loaded on chips. Samples were loaded against a common reference sample which contained equal amount of RNA from all samples.
transcription profiling by array
Shlomi Madar <email@example.com>, Shalom Madar, Varda Rotter