Abstract
Background. Epidermal growth factor receptor (EGFR) amplification and TP53 mutation are the two most common genetic alterations in glioblastoma multiforme (GBM). A comprehensive analysis of the TCGA GBM database revealed a subgroup with near mutual exclusivity of EGFR amplification and TP53 mutations indicative of a role of EGFR in regulating wild-type-p53 (wt-p53) function. The relationship between EGFR amplification and wt-p53 function remains undefined and this study describes the biological significance of this interaction in GBM. Methods. Mass spectrometry was used to identify EGFR-dependent p53-interacting proteins.The p53 and DNA-dependent protein kinase catalytic subunit (DNA-PKcs) interaction was detected by co-immunoprecipitation. We used CRISPR-Cas9 gene editing to knockout EGFR and DNA-PKcs and the Edit-R CRIPSR-Cas9 system for conditional knockout of EGFR. ROS activity was measured with a CM-H2DCFDA probe, and real-time PCR was used to quantify expression of p53 target genes. Results. Using glioma sphere-forming cells (GSCs), we identified, DNA-PKcs as a p53 interacting protein that functionally inhibits p53 activity. We demonstrate that EGFR knockdown increased wt-p53 transcriptional activity, which was associated with decreased binding between p53 and DNA-PKcs. We further show that inhibition of DNA-PKcs either by siRNA or an inhibitor (nedisertib) increased wt-p53 transcriptional activity, which was not enhanced further by EGFR knockdown, indicating that EGFR suppressed wt-p53 activity through DNA-PKcs binding with p53. Finally, using conditional EGFR-knockout GSCs, we show that depleting EGFR increased animal survival in mice transplanted with wt-p53 GSCs. Conclusion. This study demonstrates that EGFR signaling inhibits wt-p53 function in GBM by promoting an interaction between p53 and DNA-PKcs.
Original language | English (US) |
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Pages (from-to) | 1712-1725 |
Number of pages | 14 |
Journal | Neuro-oncology |
Volume | 24 |
Issue number | 10 |
DOIs | |
State | Published - Oct 1 2022 |
Keywords
- DNA-PKcs
- EGFR
- glioblastoma
- wt-p53
ASJC Scopus subject areas
- Oncology
- Clinical Neurology
- Cancer Research
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