Biology subjects

Zhang, X.-O.

Publications and source records attributed to Zhang, X.-O..

2 recordsLinked to original sources

bioRxiv2020

Protein arginine methyltransferase 5 promotes metastasis via enhancing EGFR transcription and modulating AKT1 activation by methylation

Protein arginine methyltransferase 5 (PRMT5) regulates a wide range of physiological processes, including cancer cell proliferation and metastasis, by generating symmetric di-methyl-arginine marks on histones and non-histone proteins. Here, we report that PRMT5 directly regulates epidermal growth factor receptor (EGFR) transcription to control EGF stimulated EGFR signaling. Furthermore, PRMT5 modulates protein kinase B (AKT) activation by methylation of AKT1 Arg 15, which is required for its subsequent phosphorylation at AKT1 Thr 308 and Ser 473. The PRMT5/EGFR/AKT axis converges to regulate transcription factors ZEB1, SNAIL, and TWIST1 to promote the epithelial-mesenchymal transition (EMT), in the manner that EGFR and AKT1 compensate each other to support tumor cell invasion and metastasis. Inhibiting PRMT5 methyltransferase activity with a small molecule inhibitor attenuated primary tumor growth and prevented hepatic metastasis in aggressive in vivo tumor models. Collectively, our results support the use of PRMT5 based therapies for metastatic cancer.

cancer biology↗

bioRxiv2020

Optimized RNA-targeting CRISPR/Cas13d technology outperforms shRNA in identifying essential circRNAs

Circular RNAs (circRNAs) are widely expressed, but their functions remain largely unknown. To study circRNAs in a high-throughput manner, short hairpin RNA (shRNA) screens1 have recently been used to deplete circRNAs by targeting their unique back-splicing junction (BSJ) sites. Here, we report frequent discrepancies between shRNA-mediated circRNA knockdown efficiency and the corresponding biological effect, raising pressing concerns about the robustness of shRNA screening for functional circRNAs. To address this issue, we leveraged the CRISPR/Cas13d system2 for circRNAs functional screenings. We optimized a strategy for designing single guide RNAs to deplete circRNAs. We then performed shRNA and CRISPR/Cas13d parallel screenings and demonstrated that shRNA-mediated circRNAs screening yielded a high rate of false positives phenotypes, while optimized CRISPR/Cas13d led to the identification of bona-fide functional circRNAs. Collectively, we developed a specific and reliable approach to functionalize circRNAs in a high-throughput manner.

molecular biology↗