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Transcriptome-wide off-target RNA editing induced by CRISPR-guided DNA base editors [ABE-max]

UID: 11041

Author(s): Grunewald, Julian, Lareau, Caleb A.* * MSK affiliated

Description
Summary from GEO:

"CRISPR-Cas base editor technology enables targeted nucleotide alterations and is being rapidly deployed for research and potential therapeutic applications. The most widely used base editors induce DNA cytosine (C) deamination with rat APOBEC1 (rAPOBEC1) enzyme, which is targeted by a linked Cas protein-guide RNA (gRNA) complex. Previous studies of cytosine base editor (CBE) specificity have identified off-target DNA edits in human cells. Here we show that a CBE with rAPOBEC1 can cause extensive transcriptome-wide RNA cytosine deamination in human cells, inducing tens of thousands of C-to-uracil (U) edits with frequencies ranging from 0.07% to 100% in 38% - 58% of expressed genes. CBE-induced RNA edits occur in both protein-coding and non-protein-coding sequences and generate missense, nonsense, splice site, 5’ UTR, and 3’ UTR mutations. We engineered two CBE variants bearing rAPOBEC1 mutations that substantially decrease the numbers of RNA edits (reductions of >390-fold and >3,800-fold) in human cells. These variants also showed more precise on-target DNA editing and, with the majority of gRNAs tested, editing efficiencies comparable to those observed with wild-type CBE. Finally, we show that recently described adenine base editors (ABEs) can also induce transcriptome-wide RNA edits. These results have important implications for the research and therapeutic uses of base editors, illustrate the feasibility of engineering improved variants with reduced RNA editing activities, and suggest the need to more fully define and characterize the RNA off-target effects of deaminase enzymes in base editor platforms."

Overall design from GEO:

"HEK293T cells were transfected with pCMV-ABEmax-P2A-EGFP or control pCMV-bpNLS-32AAlinker-nCas9(D10A)-bpNLS constructs with HEK site 2 gRNA as described below. Cells were sorted for top 5% GFP based on FITC signal. RNA-seq was performed to measure transcriptional changes associated with different constructs."
Subject of Study
Subject(s)
Access via GEO


Accession #: GSE126502

Access via BioProject


Accession #: PRJNA522238

Access via SRA


Accession #: SRP185812

Access Restrictions
Free to All
Access Instructions
The NCBI Gene Expression Omnibus. BioProject, and SRA databases provide open access to these files.
Associated Publications
Equipment Used
Illumina HiSeq 2500
Dataset Format(s)
TSV
Dataset Size
334.8 KB
Data Catalog Record Updated
2023-11-15