A genome-wide screen identifies E2F6 as critical factor for TMZ chemoresistance in EGFRvIII expressing GBM (DNA-seq)

We conducted a genome-wide screen by clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 library to identify genes which are particularly resistant to EGFRvIII GBM cells under the chemo-stress of TMZ. In vitro and in vivo validation of EGFRvIII-specific targets revealed several strong hits, including E2F6. Mechanistic studies demonstrated that E2F6 reveals its resistance to TMZ through NF-κB and TMZ inducement. A pooled genome-wide CRISPR-Cas9-based screen using a sgRNA lentiviral library harboring 123,411 sgRNAs which target 20,914 human genes were performed to transduce EGFRwt and EGFRvIII U87 cells ( no replicate), then treated with TMZ for 7 and 14 days. The end time point of each screen was compared to day 0 in order to determine which sgRNAs were overrepresented or underrepresented in the population.