The application discloses a liver-targeted
gene editing
system based on endogenous
promoter hijacking and application, and belongs to the field of biological
medicine. The
system is composed of an LNP-wrapped modified Cas
nuclease mRNA (first component) and a
promoter-free
viral vector carrying a therapeutic
transgene donor (second component). The
system uses LNP to realize the transient burst expression of Cas
nuclease in the liver, mediates the generation of double-strand breaks at the site of endogenous high-expression genes, induces the site-specific integration of therapeutic transgenes without exogenous promoters, and hijacks the expression driven by endogenous promoters by using the splice
acceptor (SA) mechanism. The application solves the risk of
carcinogenesis caused by random integration of exogenous strong promoters and the immunotoxicity of long-term expression of nucleases through a "double safety lock" design. Experimental results prove that the system has high editing efficiency, long-term stability and no off-target, and can be used for various liver-derived metabolic diseases such as hemophilia, hypercholesterolemia and the like.