Studies on the expression and function of Epstein-Barr virus encoded microRNAs in Burkitt lymphoma

Amoroso, Richard Benjamin Couture (2013). Studies on the expression and function of Epstein-Barr virus encoded microRNAs in Burkitt lymphoma. University of Birmingham. Ph.D.

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Abstract

Epstein-Barr virus (EBV) encodes at least 40 microRNAs (miRNAs), an important class of negative regulators that control gene expression through posttranscriptional mechanisms. However the contribution of these EBV-encoded miRNAs to the pathogenesis of virus-associated lymphomas remains poorly understood. Using newly-developed PCR assays, we first quantified the levels of viral BHRF1 and BART miRNAs in a range of EBV-positive cell lines. We show for the first time that all three BHRF1 miRNAs are abundantly expressed in Wp-restricted Burkitt lymphoma (BL) cells, but not Latency I BL cells lacking detectable Cp- or Wp-initiated EBNA transcripts. In contrast to some earlier reports, we also detected robust expression of BART miRNAs in B cell lines, although there was wide variation between individual miRNAs in a given cell. Analysis of BHRF1 and BART transcription, both in latent and lytic infection, suggested that maturation may be a key step in regulating steady-state miRNA levels. We also successfully generated lentiviral systems to express the BHRF1 miRNAs and developed reporter constructs to measure BHRF1 miRNA-dependent repression \(in\) \(vivo\). While attempts to identify BHRF1 miRNA-induced changes on the BL transcriptome were inconclusive, our data suggest that the BHRF1 miRNAs are insufficient to affect BL cell growth and cell survival.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

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