The role of cellular micro-RNAs in Epstein-Barr virus induced cellular transformation and oncogenesis

Smith, Nikki (2011). The role of cellular micro-RNAs in Epstein-Barr virus induced cellular transformation and oncogenesis. University of Birmingham. Ph.D.

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Abstract

Micro-RNAs (miRNAs) are a class of non-coding RNA which post-transcriptionally regulate gene expression. Epstein-Barr Virus (EBV) transforms resting B-cells in vitro to establish continuously proliferating lymphoblastoid cell lines (LCLs) and is aetiologically linked to lymphomas. Little is known about the contribution of miRNAs to the transformation of B cells. We initially examined the regulation of the oncogenic miR-155, which is highly expressed in Hodgkin’s lymphoma but was reportedly absent in Burkitt’s lymphoma. We found that miR-155 was up-regulated by EBV-LMP1 expression, and that a reported defect of miR-155 processing in Burkitt’s lymphoma was a misinterpretation of data. Next, to identify cellular miRNAs and genes modulated during EBV-induced transformation, we compared the expression profiles of resting B cells and B cells either infected with EBV or stimulated to proliferate with CD40L and IL4. This revealed that a large proportion of miRNAs and genes differentially regulated by EBV and not by CD40L/IL4 were modulated by EBV interaction with its CD21 receptor complex, but these changes were maintained or amplified in LCLs; and included a set of tumour suppressor genes down-regulated by EBV. In addition, bioinformatics analysis indicated that EBV modulates the expression of multiple miRNAs predicted to target the same cellular genes.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):