Genome-wide CRISPR screen identifies ELP5 as a determinant of gemcitabine sensitivity in gallbladder cancer

• Published in: Nature communications 2019-12, Vol.10 (1), p.5492-14, Article 5492
• Main Authors: Xu, Sunwang, Zhan, Ming, Jiang, Cen, He, Min, Yang, Linhua, Shen, Hui, Huang, Shuai, Huang, Xince, Lin, Ruirong, Shi, Yongheng, Liu, Qiang, Chen, Wei, Mohan, Man, Wang, Jian
• Format: Article
• Language: English
• Subjects: 13/1; 13/105; 13/109; 13/2; 13/31; 14; 42; 42/40; 45/47; 631/67/1504; 631/80/82; 64/60; Adult; Aged; Aged, 80 and over; Antimetabolites, Antineoplastic - administration & dosage; Apoptosis; Apoptosis - drug effects; Cancer; Carrier Proteins - antagonists & inhibitors; Carrier Proteins - genetics; Carrier Proteins - metabolism; Chemotherapy; Clustered Regularly Interspaced Short Palindromic Repeats; Cohort Studies; CRISPR; Deoxycytidine - administration & dosage; Deoxycytidine - analogs & derivatives; Elongation; Female; Gallbladder; Gallbladder cancer; Gallbladder Neoplasms - drug therapy; Gallbladder Neoplasms - genetics; Gallbladder Neoplasms - metabolism; Gemcitabine; Genome-Wide Association Study; Genomes; Heterogeneous-Nuclear Ribonucleoproteins - genetics; Heterogeneous-Nuclear Ribonucleoproteins - metabolism; Humanities and Social Sciences; Humans; Internal Ribosome Entry Sites; Male; Metastases; Middle Aged; mRNA; multidisciplinary; p53 Protein; RNA Processing, Post-Transcriptional; RNA, Transfer - genetics; RNA, Transfer - metabolism; Science; Science (multidisciplinary); Sensitivity; Translation; tRNA; tRNA Ala; Tumor Suppressor Protein p53 - genetics; Tumor Suppressor Protein p53 - metabolism; Uridine
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-13420-x

Gemcitabine is the first-line treatment for locally advanced and metastatic gallbladder cancer (GBC), but poor gemcitabine response is universal. Here, we utilize a genome-wide CRISPR screen to identify that loss of ELP5 reduces the gemcitabine-induced apoptosis in GBC cells in a P53-dependent manner through the Elongator complex and other uridine 34 (U 34 ) tRNA-modifying enzymes. Mechanistically, loss of ELP5 impairs the integrity and stability of the Elongator complex to abrogate wobble U 34 tRNA modification, and directly impedes the wobble U 34 modification-dependent translation of hnRNPQ mRNA, a validated P53 internal ribosomal entry site (IRES) trans -acting factor. Downregulated hnRNPQ is unable to drive P53 IRES-dependent translation, but rescuing a U 34 modification-independent hnRNPQ mutant could restore P53 translation and gemcitabine sensitivity in ELP5 -depleted GBC cells. GBC patients with lower ELP5, hnRNPQ, or P53 expression have poor survival outcomes after gemcitabine chemotherapy. These results indicate that the Elongator/hnRNPQ/P53 axis controls gemcitabine sensitivity in GBC cells. Gemcitabine is used to treat gallbaldder cancer but patient responses are variable. Here, the authors use a genome-wide CRISPR screen and identify the translational elongator protein ELP5 as a protein that is important for mediating gemcitabine-induced apoptosis.