MicroRNA alterations in Barrett's esophagus, esophageal adenocarcinoma, and esophageal adenocarcinoma cell lines following cranberry extract treatment: Insights for chemoprevention

Abstract

Background: Aberrant expression of small noncoding endogenous RNA molecules known as microRNAs (miRNAs) is documented to occur in multiple cancer types including esophageal adencarcinoma (EAC) and its only known precursor, Barrett's esophagus (BE). Recent studies have linked dysregulation of specific miRNAs to histological grade, neoplastic progression and metastatic potential.

Materials and methods: Herein, we present a summary of previously reported dysregulated miRNAs in BE and EAC tissues as well as EAC cell lines and evaluate a cranberry proanthocyanidin rich extract's (C-PAC) ability to modulate miRNA expression patterns of three human EAC cell lines (JHEso-Ad-1, OE33 and OE19).

Results: A review of 13 published studies revealed dysregulation of 87 miRNAs in BE and EAC tissues, whereas 52 miRNAs have been reported to be altered in BE or EAC cell lines, with 48% overlap with miRNA changes reported in tissues. We report for the first time C-PAC-induced modulation of five miRNAs in three EAC cell lines resulting in 26 validated gene targets and identification of key signaling pathways including p53, angiogenesis, T-cell activation and apoptosis. Additionally, mutiple cancer related networks were ideintified as modulated by C-PAC utilizing Kyoto Encyclopedia of Genes and Genomes (KEGG), Protein Analysis Through Evolutionary Relationships (PANTHER), and MetaCore analysis tools.

Conclusions: Study results support the cancer inhibitory potential of C-PAC is in part attributable to C-PAC's ability to modify miRNA profiles within EAC cells. A number of C-PAC-modulated miRNAs have been been identified as dysregulated in BE and EAC. Further insights into miRNA dysregulation and modulation by select cancer preventive agents will support improved targeted interventions in high-risk cohorts.

Keywords: Barrett's esophagus; JHAD1; OE19; OE33; chemoprevention; cranberry; esophageal adenocarcinoma; microRNA; polyphenols; proanthocyanidins.

Figure 1

Inhibition of cell viability by cranberry proanthocyanidins (C-PAC). (a) C-PAC–induced inhibition of JHAD1 cellular viability over time. (b) C-PAC–induced inhibition of OE19 cellular viability over time. Reported inhibition is relative to vehicle or media-treated esophageal adenocarcinoma cells. Evaluations were in replicates of six per cell line, per experimental time point (^*P < 0.05, significantly different from media-treated controls by t-test)

Figure 2

Effects of C-PAC treatment on miRNA expression patterns in JHAD1, OE19 and OE33 esophageal adenocarcinoma cell lines. (a) Details of commonly up and downregulated miRNAs following a 6-hour C-PAC treatment by cell line; (b) Venn diagram illustrating the number of C-PAC upregulated miRNAs in each cell line; (c) Venn diagram illustrating the number of downregulated miRNAs associated with C-PAC treatment