A review of the current understanding and clinical utility of miRNAs in esophageal cancer

Abstract

Background: MicroRNAs (miRNAs) are a class of small, well-conserved, non-coding RNAs that regulate the translation of RNAs. They have a role in biological and pathological process including cell differentiation, apoptosis, proliferation and metabolism. Since their discovery, they have been shown to have a potential role in cancer pathogenesis through their function as oncogenes or tumor suppressors. A substantial number of miRNAs show differential expression in esophageal cancer tissues, and so have been investigated for possible use in diagnosis. Furthermore, there is increasing interest in their use as prognostic markers and determining treatment response, as well as identifying their downstream targets and understanding their mode of action.

Methods: We analyzed the most recent studies on miRNAs in esophageal cancer and/or Barrett's esophagus (BE). The publications were identified by searching in PuBMed for the following terms: Barrett's esophagus and microRNA; esophageal cancer and microRNA.

Results: Four miRNAs (mi-R-25, -99a, -133a and -133b) showed good potential as diagnostic markers and interestingly five (mi-R-21, -27b, -126, - 143 and -145) appeared to be useful both as diagnostic and prognostic/predictive markers.

Conclusion: The data so far on miRNAs in esophageal carcinogenesis is promising but further work is required to determine whether miRNAs can be used as biomarkers, not only in the clinical setting or added to individualized treatment regimes but also in non-invasive test by making use of miRNAs identified in blood.

Keywords: 5-FU; 5-fluorouracil; B cell lymphoma 2; BE; Barrett's esophagus; Bcl-2; Biomarkers; CD47; CDH1; Cluster of differentiation 47; DGCR8; DICER1; Diagnosis; E-Cadherin; EAC; ESCC; Esophageal adenocarcinoma; Esophageal squamous cell carcinoma; F box/WD repeat containing protein 7; FBXW7; FSCN1; HGD; High grade dysplasia; IGF1R; IRS; Insulin like growth factor receptor 1; LATS2; LDHB; LGD; LNM; Low grade dysplasia; Lymph node metastasis; MDR1; MISH; MicroRNA; MicroRNA [ribonucleic acid]; NE; Normal epithelium; Oesophageal cancer; P27; PPP2R1B; Pasha protein; Prognosis; Protein 53; Quantitative reverse transcription polymerase chain reaction; RNA; RNASEN; Rap1a; Rap1b; Ras related protein 1a; Ras related protein 1b; Ribonuclease 3 enzyme gene; ascin homolog 1, actin bundling protein; endoribonuclease of RNase III family; inflammatory risk score; lactate dehydrogenase B; large tumor suppressor, homolog 2; miRNA in situ hybridization; miRNA/miR; multi drug resistance 1; p53; protein 27; protein phosphatase 2 regulatory subunit beta isoform; qRT-PCR; ribonucleic acid.