Non-coding RNAs and colitis-associated cancer: Mechanisms and clinical applications

Colitis-associated cancer (CAC) is one of the most severe complications of inflammatory bowel disease (IBD), which has caused a worse survival rate in IBD patients. Although the exact aetiology and pathogenesis of CAC are not completely elucidated, evidence indicates that non-coding RNAs are closely involved and play a key role.

This review aims to summarise the major findings of non-coding RNAs in the development of CAC and present the potential mechanistic links between non-coding RNAs and CAC pathogenesis. The results show that non-coding RNAs can hinder DNA mismatch repair proteins and obstruct chromosome passenger complexes to increase microsatellite instability and accumulate chromosomal instability, respectively. The data also suggest that DNA promoter methylation or RNA methylation modifications of non-coding RNA are the main mechanisms to regulate oncogene or tumour suppressor expression during the CAC progression. Other factors, including gut microbiota perturbations, immune dysregulation and barrier dysfunction, are also regulated and influenced by non-coding RNAs. Besides, non-coding RNAs as molecular managers are associated with multiple critical signalling pathways governing the initiation, progression and metastasis of CAC, including the janus kinase/signal transducer and activator of transcription (JAK/STAT), nuclear factor-kappa B (NF-κB), extracellular signal-regulated kinase (ERK), Toll-like receptor 4 (TLR4), Wnt/β-catenin and phosphatidylinositol 3-Kinase/Protein Kinase B (PI3K/AKT) pathways. In addition, non-coding RNAs can be detected in colon tissues or blood, and their aberrant expressions and diagnostic and prognostic roles are also discussed and confirmed in CAC patients.

It is believed that a deepening understanding of non-coding RNAs in CAC pathogenesis may prevent the progression to carcinogenesis, and will offer new effective therapies for CAC patients.