| Abstract: | Erlotinib is highly effective in lung cancer patients with epidermal growth factor receptor (EGFR) mutations. However, despite initial favorable responses, most patients rapidly develop resistance to erlotinib soon after the initial treatment. This study aims to identify new genes and pathways associated with erlotinib resistance mechanisms in order to develop novel therapeutic strategies. Here, we induced knockout (KO) mutations in erlotinib‐resistant human lung cancer cells (NCI‐H820) using a genome‐scale CRISPR‐Cas9 sgRNA library to screen for genes involved in erlotinib susceptibility. The spectrum of sgRNAs incorporated among erlotinib‐treated cells was substantially different to that of the untreated cells. Gene set analyses showed a significant depletion of ‘cell cycle process’ and ‘protein ubiquitination pathway’ genes among erlotinib‐treated cells. Chemical inhibitors targeting genes in these two pathways, such as nutlin‐3 and carfilzomib, increased cancer cell death when combined with erlotinib in both in vitro cell line and in vivo patient‐derived xenograft experiments. Therefore, we propose that targeting cell cycle processes or protein ubiquitination pathways are promising treatment strategies for overcoming resistance to EGFR inhibitors in lung cancer.Abbreviations- ATCC
- American Type Culture Collection
- edgeR
- bioconductor software package for examining differential expression of replicated count data
- EGFR
- epidermal growth factor receptor
- GeCKO
- genome‐scale CRISPR/Cas9 knockout
- HGF
- hepatocyte growth factor
- MAGeCK‐VISPR algorithm
- comprehensive quality control analysis and visualization pipeline for CRISPR/Cas9 screens based on MAGeCK VISPR
- MOI
- multiplicity of infection
- NSCLC
- non‐small‐cell lung cancer
- SCLC
- small cell lung cancer
- sgRNA
- single‐guide RNA
- TKIs
- tyrosine kinase inhibitors
|
