Genome-wide CRISPR screen identifies ELP5 as a determinant of gemcitabine sensitivity in gallbladder cancer
Genome-wide CRISPR screen identifies ELP5 as a determinant of gemcitabine sensitivity in gallbladder cancer
复制标题
全基因组 CRISPR 筛选确定 ELP5 是胆囊癌吉西他滨敏感性的决定因素
DOI：
10.1038/s41467-019-13420-x
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发表时间：
2019-12-02
影响因子：
16.6
通讯作者：
Wang, Jian
中科院分区：
文献类型：
--
作者：
Xu, Sunwang;Zhan, Ming;Wang, Jian
吉西他滨是局部晚期和转移性胆囊癌（GBC）的一线治疗，但吉西他滨不良反应是普遍存在的。在这里，我们利用全基因组CRISPR筛选来确定ELP5的缺失通过延长复合体和其他尿苷34 (U34) trna修饰酶以p53依赖的方式减少吉西他滨诱导的GBC细胞凋亡。从机制上说，ELP5的缺失会损害消除摆动U34tRNA修饰的细长复合物的完整性和稳定性，并直接阻碍摆动u34修饰依赖于hnRNPQ mRNA的翻译，hnRNPQ mRNA是P53内部核糖体进入位点（IRES）反式作用因子。下调的hnRNPQ不能驱动P53 ires依赖性翻译，但是挽救一个不依赖于u34修饰的hnRNPQ突变体可以恢复P53翻译和在elp5缺失的GBC细胞中对吉西他滨的敏感性。ELP5、hnRNPQ或P53表达较低的GBC患者在吉西他滨化疗后生存率较差。这些结果表明，伸长/hnRNPQ/P53轴控制着GBC细胞对吉西他滨的敏感性。
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 (U34) tRNA-modifying enzymes. Mechanistically, loss of ELP5 impairs the integrity and stability of the Elongator complex to abrogate wobble U34tRNA modification, and directly impedes the wobble U34modification-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 U34modification-independent hnRNPQ mutant could restore P53 translation and gemcitabine sensitivity inELP5-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.