TBIO-26. NON-CANONICAL OPEN READING FRAMES ENCODE FUNCTIONAL PROTEINS ESSENTIAL FOR CANCER CELL SURVIVAL

Autor: Zhe Ji, Ginevra Botta, Todd R. Golub, Victor Luria, Joshua M. Dempster, Nicholas J. Lyons, Briana Fritchman, Federica Piccioni, Karolina Stumbraite, Karl R. Clauser, Jacob D. Jaffe, Zohra Kalani, David E. Root, Vickie M. Wang, Li Wang, Douglas Alan, Oana M. Enache, Adam Brown, Marc W. Kirschner, Jennifer Roth, Thomas M Green, Karsten Krug, John R. Prensner, Amy Goodale, Xiaoping Yang, Amir Karger
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Neuro-Oncology
ISSN: 1523-5866
1522-8517
Popis: The brain is the foremost non-gonadal tissue for expression of non-coding RNAs of unclear function. Yet, whether such transcripts are truly non-coding or rather the source of non-canonical protein translation is unknown. Here, we used functional genomic screens to establish the cellular bioactivity of non-canonical proteins located in putative non-coding RNAs or untranslated regions of protein-coding genes. We experimentally interrogated 553 open reading frames (ORFs) identified by ribosome profiling for three major phenotypes: 257 (46%) demonstrated protein translation when ectopically expressed in HEK293T cells, 401 (73%) induced gene expression changes following ectopic expression across 4 cancer cell types, and 57 (10%) induced a viability defect when the endogenous ORF was knocked out using CRISPR/Cas9 in 8 human cancer cell lines. CRISPR tiling and start codon mutagenesis indicated that the biological impact of these non-canonical ORFs required their translation as opposed to RNA-mediated effects. We functionally characterized one of these ORFs, G029442—renamed GREP1 (Glycine-Rich Extracellular Protein-1)—as a cancer-implicated gene with high expression in multiple cancer types, such as gliomas. GREP1 knockout in >200 cancer cell lines reduced cell viability in multiple cancer types, including glioblastoma, in a cell-autonomous manner and produced cell cycle arrest via single-cell RNA sequencing. Analysis of the secretome of GREP1-expressing cells showed increased abundance of the oncogenic cytokine GDF15, and GDF15 supplementation mitigated the growth inhibitory effect of GREP1 knock-out. Taken together, these experiments suggest that the non-canonical ORFeome is surprisingly rich in biologically active proteins and potential cancer therapeutic targets deserving of further study.
Databáze: OpenAIRE
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