Expression and Function of miR-155 in Diseases of the Gastrointestinal Tract.

Jianhua Wan,Wenting Xu,Liang Xia,Nonghua Lu

doi:10.3390/ijms17050709

Abstract

MicroRNAs (miRNAs) are a type of small noncoding RNA that can regulate the expression of target genes under physiological and pathophysiological conditions. miR-155 is a multifunctional miRNA with inflammation-related and oncogenic roles. In particular, the dysregulation of miR-155 has been strongly implicated in Helicobacter pylori-related gastric disease, inflammatory bowel disease, and colorectal cancer in addition to being involved in molecular changes of important targets and signaling pathways. This review focuses on the expression and function of miR-155 during inflammation and carcinogenesis and its potential use as an effective therapeutic target for certain gastrointestinal diseases.

Highlights

MicroRNAs are an abundant class of small noncoding RNAs that mostly down-regulate protein expression by either inducing mRNA degradation or suppressing protein synthesis
Saito et al [43] found that the expression levels of miR-155 in gastric MALT lymphoma lesions were significantly higher than those in the corresponding non-tumor gastric mucosae using miRNA microarray analysis and quantitative RT-PCR; this is associated with H. pylori eradication by targeting tumor protein p53-inducible nuclear protein 1(TP53INP), which induces cell cycle arrest and apoptosis
The intestinal mucosal barrier plays an indispensable role in maintaining normalintestinal function and is composed of a layer of cross-linked, highly differentiated epithelial cells located at the apical junction complex (AJC). miR-155 over-expression inhibits RhoA protein expression, which down-regulates the expression of zonula occludens-1 (ZO-1) and E-cadherin, two major component proteins of the AJC [62]

Summary

Introduction

MicroRNAs (miRNAs) are an abundant class of small noncoding RNAs that mostly down-regulate protein expression by either inducing mRNA degradation or suppressing protein synthesis. Pri-miRNA cleaves to the miRNA precursor (pre-miRNA) via the RNase III enzyme Drosha and the double-stranded-RNA-binding protein DGCR8 [2]. Numerous reports indicate that miRNAs are associated with the posttranscriptional regulation of many proteins that are involved in numerous physiological and pathological processes [6,7], such as hematopoietic lineage differentiation, immunity, inflammation, cancer, and cardiovascular diseases [8]. Abnormal miR-155 expression can be detected during Helicobacter pylori infection, and increased expression is observed in patients with inflammatory bowel disease (IBD) and colorectal cancer (CRC) [11,12,13]. MiR-155 may have unique functions in the immune-mediated process of certain gastrointestinal diseases

Inflammation and Cancer

Intestinal Diseases

Findings

Discussion and Conclusions