Date of Award

11-1-2023

Degree Type

Thesis

Degree Name

MPhil in Biological and Biomedical Sciences

First Advisor

Dr Kulsoom Ghias

Second Advisor

Dr Syed Hani Abidi

Third Advisor

Khalid Ahmed

Department

Biological and Biomedical Sciences

Abstract

The Epstein-Barr Virus (EBV) has been associated with the progression of prostate cancer. However, the exact molecular mechanisms through which EBV drives the advancement of prostate cancer remain unknown. In order to elucidate the molecular events and pathways that are involved in EBV-driven cancer progression, the prostate cancer cell line DU145 was used as an experimental model to investigate the impact of EBV oncoproteins, LMP1, LMP2, and their combination on the TGF-β pathway, the JAK/STAT pathway, and key epithelial to mesenchymal transition (EMT) markers. DU145 cells were transiently transfected with LMP1, LMP2, or LMP1 and LMP2. The expression of EMT markers and genes in the TGF-β and the JAK/STAT pathway were assessed using qPCR. Subsequently, selected differentially expressed genes were assessed at the protein level through western blotting and immunocytochemistry (ICC), and pathway analysis of the differentially expressed genes was performed. Functionally, the migratory ability of transfected cells was assessed through scratch test assay. qPCR results showed that both LMP1 and LMP2, separately and in combination, led to the downregulation of the SMAD-dependent TGF-β pathway genes while simultaneously upregulating the the TGF-βR1 receptor. In the JAK/STAT pathway, LMP1, LMP2, and co-transfection upregulated JAK1 and TYK2, while STAT3 was upregulated in LMP1 and co-transfected cells. Among the EMT markers, N-cadherin was upregulated, while vimentin was downregulated in all the transfected cells. Additionally, Ecadherin was also downregulated in all except co-transfected cells. The rest of the EMT markers showed varied responses to LMP1, LMP2, and co-transfection. Western blotting and ICC results corroborated some of these alterations in the EMT markers at the protein level. LMP1 and LMP2 transfection enhanced the migratory ability of the cells, with the most significant effect observed in the co-transfected cells. Pathway analysis results showed that interleukin mediated signaling and positive regulation of cardiac epithelial-to-mesenchymal transition were enriched terms associated with the differentially expressed genes. Overall, LMP1 and LMP2 appear to be involved in the EMT program in DU145 prostate cancer cells by down-regulating the canonical-TGF-β pathway and signaling through the JAK/STAT pathway.

First Page

1

Last Page

85

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