TABLE 1.

Circulating miRNAs and their possible/identified targets in different gastrointestinal disorders.

Circulating miRNAs	Diseases	Up/down	Potential/identified target genes	Roles	References
miR-25-3p	CRC	Up	KLF2, KLF4	Promoting CRC vascular permeability and angiogenesis	Zeng et al., 2018
miR-106b-3p	CRC	Up	DLC-1	Promoting CRC metastasis	Liu et al., 2020
miR-1229	CRC	Up	HIPK2	Promoting CRC angiogenesis	Hu et al., 2019
miR-590-5p	CRC	Down	NF90	Inhibiting CRC angiogenesis and metastasis	Zhou Q. et al., 2016
miR-622	CRC	Down	CXCR4, K-Ras	Inhibiting CRC angiogenesis and metastasis	Fang et al., 2016, 2019
miR-382	CRC	Down	NR2F2	Inhibiting CRC cell growth and invasion	Zhou B. et al., 2016
miR-409-3p	CRC	Down	Beclin-1	Inhibiting autophagy	Tan et al., 2016
miR-223	IBD	Up	CLDN8	Dysfunction of the intestinal epithelial barrier	Wang et al., 2016
miR-21	IBD	Up	RhoB	Dysfunction of the intestinal epithelial barrier	Yang et al., 2013
miR-320	IBD	Down	NOD2	Disruption of immune homeostasis	Pierdomenico et al., 2016
miR-31	IBD	Up	IL6st, IL7r, IL17ra	Suppressing inflammation	Tian et al., 2019

Up and down indicate upregulated and downregulated circulating miRNA expression levels in diseased tissues compared with normal tissues, respectively. Roles, roles of miRNAs in the pathogenesis of gastrointestinal disorders; CRC, colorectal cancer; IBD, inflammatory bowel disease.