RESUMO
EGFR-mutant NSCLCs frequently respond to EGFR tyrosine kinase inhibitors (TKIs). However, the responses are not durable, and the magnitude of tumor regression is variable, suggesting the existence of genetic modifiers of EGFR dependency. Here, we applied a genome-wide CRISPR-Cas9 screening to identify genetic determinants of EGFR TKI sensitivity and uncovered putative candidates. We show that knockout of RIC8A, essential for G-alpha protein activation, enhanced EGFR TKI-induced cell death. Mechanistically, we demonstrate that RIC8A is a positive regulator of YAP signaling, activation of which rescued the EGFR TKI sensitizing phenotype resulting from RIC8A knockout. We also show that knockout of ARIH2, or other components in the Cullin-5 E3 complex, conferred resistance to EGFR inhibition, in part by promoting nascent protein synthesis through METAP2. Together, these data uncover a spectrum of previously unidentified regulators of EGFR TKI sensitivity in EGFR-mutant human NSCLC, providing insights into the heterogeneity of EGFR TKI treatment responses.
Assuntos
Sistemas CRISPR-Cas , Carcinoma Pulmonar de Células não Pequenas/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Células A549 , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Linhagem Celular Tumoral , Proteínas Culina , Receptores ErbB/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Inativação de Genes , Fatores de Troca do Nucleotídeo Guanina/genética , Células HEK293 , Humanos , Metionil Aminopeptidases/metabolismo , Camundongos , Camundongos Nus , Receptores de Ácidos Lisofosfatídicos/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo , Transcriptoma , Ubiquitina-Proteína Ligases/genética , Proteínas de Sinalização YAP , Proteína rhoA de Ligação ao GTP/metabolismoRESUMO
We have used a combination of SDS-PAGE and LTQ-Orbitrap MS to explore the proteome of the highly invasive MDA-MB-231 breast cancer cell line. Based on about 520 000 MS/MS spectra, a total of 3481 proteins were identified and subsequently classified according to their cellular distribution and molecular function. Interestingly, a large proportion of proteins (38%) were from cellular membranes and we were able to characterize numerous proteins involved in cancer initiation and progression such as the tumor suppressor p53 and the epidermal growth factor receptor. Together, this study represents the largest proteome database of breast cancer cells realized to date and demonstrates the value of using Orbitrap MS for deeper proteome analysis.