Genes 2014, 5(3), 726-738; https://doi.org/10.3390/genes5030726
Enterococcus faecalis Infection and Reactive Oxygen Species Down-Regulates the miR-17-92 Cluster in Gastric Adenocarcinoma Cell Culture
1
Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen 2200, Denmark
2
Center for Genomic Medicine, Rigshospitalet, University of Copenhagen, Copenhagen 2100, Denmark
3
Department of Clinical Biochemistry, Næstved Hospital, Næstved 4700, Denmark
*
Author to whom correspondence should be addressed.
Received: 5 May 2014 / Revised: 14 July 2014 / Accepted: 13 August 2014 / Published: 28 August 2014
(This article belongs to the Special Issue miRNA Regulation)
Abstract
Chronic inflammation due to bacterial overgrowth of the stomach predisposes to the development of gastric cancer and is also associated with high levels of reactive oxygen species (ROS). In recent years increasing attention has been drawn to microRNAs (miRNAs) due to their role in the pathogenesis of many human diseases including gastric cancer. Here we studied the impact of infection by the gram-positive bacteria Enterococcus faecalis (E. faecalis) on global miRNA expression as well as the effect of ROS on selected miRNAs. Human gastric adenocarcinoma cell line MKN74 was infected with living E. faecalis for 24 h or for 5 days or with E. faecalis lysate for 5 days. The miRNA expression was examined by microarray analysis using Affymetrix GeneChip miRNA Arrays. To test the effect of ROS, MKN74 cells were treated with 100 mM tert-Butyl hydroperoxide (TBHP). Following 5 days of E. faecalis infection we found 91 differentially expressed miRNAs in response to living bacteria and 2 miRNAs responded to E. faecalis lysate. We verified the down-regulation of the miR-17-92 and miR-106-363 clusters and of other miRNAs involved in the oxidative stress-response by qRT-PCR. We conclude that only infection by living E. faecalis bacteria caused a significant global response in miRNA expression in the MKN74 cell culture. E. faecalis infection as well as ROS stimulation down-regulated the expression of the miR-17-92 cluster. We believe that these changes could reflect a general response of gastric epithelial cells to bacterial infections. View Full-TextKeywords:
miRNA; reactive oxygen species; E. faecalis; miR-17-92 cluster; infection
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MDPI and ACS Style
Strickertsson, J.A.B.; Rasmussen, L.J.; Friis-Hansen, L. Enterococcus faecalis Infection and Reactive Oxygen Species Down-Regulates the miR-17-92 Cluster in Gastric Adenocarcinoma Cell Culture. Genes 2014, 5, 726-738.