Gene, genetics and genetic medicines in gastroenterology: Current status and its future

Table 15 Newer techniques of gene editing tools and their applications in gastrointestinal tract disorders

Technique	Mechanism	GIT applications
CRISPR-Cas9/12/13	DNA or RNA targeting via guide RNA and nuclease	Cancer mutations (APC, KRAS), viral hepatitis, IBD models
Base/prime editing	Precise base or sequence correction without DSBs	CFTR mutations, APC mutations
ZFNs	DNA-binding proteins fused to nucleases	HBV suppression (preclinical)
TALENs	TALE DNA-binding fused to nucleases	Cancer cell targeting, liver disease models
Epigenome editing	dCas9 fused to activators/repressors	Regulation of PD-L1, IBD immune genes
RNAi (siRNA, ASO)	Degrade/block specific mRNAs	Lumasiran (PH1), fazirsiran (A1AT deficiency)

GIT: Gastrointestinal tract; CRISPR: Clustered regularly interspaced short palindromic repeats; ZFNs: Zinc finger nucleases; TALENs: Transcription activator-like effector nucleases; RNAi: RNA interference; ASO: Antisense oligonucleotides; siRNA: Small interfering RNA; mRNA: Messenger RNA; DSBs: Double-strand breaks; TALE: Transcription activator-like effector; dCas9: Dead clustered regularly interspaced short palindromic repeats-associated protein 9; IBD: Inflammatory bowel disease; HBV: Hepatitis B virus; PD-L1: Programmed death-ligand 1.