CRISPR/Cas9 Gene Editing System Can Alter Gene Expression and Induce DNA Damage Accumulation.

Clustered regularly interspaced short palindromic repeats (CRISPR) and the associated protein (Cas) gene editing can induce P53 activation, large genome fragment deletions, and chromosomal structural variations. Here, gene expression was detected in host cells using transcriptome sequencing following CRISPR/Cas9 gene editing. We found that the gene editing reshaped the gene expression, and the number of differentially expressed genes was correlated with the gene editing efficiency. Moreover, we found that alternative splicing occurred at random sites and that targeting a single site for gene editing may not result in the formation of fusion genes. Further, gene ontology and KEGG enrichment analysis showed that gene editing altered the fundamental biological processes and pathways associated with diseases. Finally, we found that cell growth was not affected; however, the DNA damage response protein-γH2AX-was activated. This study revealed that CRISPR/Cas9 gene editing may induce cancer-related changes and provided basic data for research on the safety risks associated with the use of the CRISPR/Cas9 system.