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Louisiana Cancer Research Consortium,1 Tulane Cancer Center,2 Department of Pathology,3 Department of Mathematics, Tulane University, New Orleans, Louisiana4
Received 2 November 2007/ Accepted 13 March 2008
The cellular microRNA miR-155 has been shown to be involved in lymphocyte activation and is expressed in Epstein-Barr virus (EBV)-infected cells displaying type III latency gene expression but not type I latency gene expression. We show here that the elevated levels of miR-155 in type III latency cells is due to EBV gene expression and not epigenetic differences in cell lines tested, and we show that expression in EBV-infected cells requires a conserved AP-1 element in the miR-155 promoter. Gene expression analysis was carried out in a type I latency cell line transduced with an miR-155-expressing retrovirus. This analysis identified both miR-155-suppressed and -induced cellular mRNAs and suggested that in addition to direct targeting of 3' untranslated regions (UTRs), miR-155 alters gene expression in part through the alteration of signal transduction pathways. 3' UTR reporter analysis of predicted miR-155 target genes identified the transcriptional regulatory genes encoding BACH1, ZIC3, HIVEP2, CEBPB, ZNF652, ARID2, and SMAD5 as miR-155 targets. Western blot analysis of the most highly suppressed of these, BACH1, showed lower expression in cells transduced with a miR-155 retrovirus. Inspection of the promoters from genes regulated in EBV-infected cells and in cells infected with an miR-155 retrovirus identified potential binding sequences for BACH1 and ZIC3. Together, these experiments suggest that the induction of miR-155 by EBV contributes to EBV-mediated signaling in part through the modulation of transcriptional regulatory factors.
Published ahead of print on 26 March 2008.
Supplemental material for this article may be found at http://jvi.asm.org/.
| J. Bacteriol. | Mol. Cell. Biol. | Microbiol. Mol. Biol. Rev. |
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| Clin. Vaccine Immunol. | ALL ASM JOURNALS |
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