Recent Advancements in Reducing the Off-Target Effect of CRISPR-Cas9 Genome Editing
Misganaw Asmamaw Mengstie, Muluken Teshome Azezew, Tadesse Asmamaw Dejenie, Assefa Agegnehu Teshome, Fitalew Tadele Admasu, Awgichew Behaile Teklemariam, Anemut Tilahun, Melaku Mekonnen Agidew, Dagnew Getnet Adugna, Habtamu Geremew, Endeshaw Chekol Abebe
Abstract
The CRISPR-Cas (Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)) and the associated protein (Cas9) system, a young but well-studied genome-editing tool, holds plausible solutions to a wide range of genetic disorders. The single-guide RNA (sgRNA) with a 20-base user-defined spacer sequence and the Cas9 endonuclease form the core of the CRISPR-Cas9 system. This sgRNA can direct the Cas9 nuclease to any genomic region that includes a protospacer adjacent motif (PAM) just downstream and matches the spacer sequence. The current challenge in the clinical applications of CRISPR-Cas9 genome-editing technology is the potential off-target effects that can cause DNA cleavage at the incorrect sites. Off-target genome editing confuses and diminishes the therapeutic potential of CRISPR-Cas9 in addition to potentially casting doubt on scientific findings regarding the activities of genes. In this review, we summarize the recent technological advancements in reducing the off-target effect of CRISPR-Cas9 genome editing.