<p>F factor plasmid-mediated Epstein-Barr virus genome introduction establishes an EBV positive NPC cell model</p>

Abstract

Background Most Epstein-Barr virus (EBV)-positive cells lose the EBV episomes upon prolonged propagation. Purpose The purposes of this study were to establish a simple cell model for nasopharyngeal carcinoma (NPC) research by introducing a plasmid with the EBV genome into NPC cells and then to investigate the resulting changes in malignant biological behaviour and NPC-associated signalling pathways. Methods HONE1 NPC cells were transfected with F-factor plasmids including the EBV genome (HONE1-EBV cells). Then cell proliferation, migration, cell cycle distribution and apoptosis were evaluated in vitro by using CCK8, transwell and flow cytometry assays respectively. EBV-encoded proteins and cell signal tranducting proteins were detected by western blot assays. EBV-encoded RNAs were detected by in situ hybridization. EBV particles were assayed by transmission electron microscope (TEM). The morphology of cells were detected by immunofluorescence assays for alpha-tubulin. Results Latent membrane protein 1 (LMP1), latent membrane protein 2A (LMP2A), Epstein-Barr nuclear antigen 1 (EBNA1) and EBV-encoded small RNAs (EBERs) were successfully expressed in HONE1-EBV cells. No EBV particles were founded by TEM. Introduction of the EBV genome significantly promoted proliferation, cell cycle progression and migration and inhibited apoptosis in HONE1 cells. Immunofluorescence assays showed that the morphology of HONE1-EBV cells changed into spindle. Furthermore, EBV genome introduction significantly inhibited the JAK/STAT signalling pathway, while it activated the PI3K-AKT and NF-κB signalling pathways in HONE1 cells. Conclusion These findings suggest that F-factor plasmid-mediated EBV genome introduction was successful in constructing an EBV positive cell model, which showed deteriorated biological behavior and activated NPC-associated signalling pathways. This model can serve as a good tool for studying EBV in NPC, but the subtle differences in cancer-associated pathways must be considered.

Comprehensive analysis of key genes associated with ceRNA networks in nasopharyngeal carcinoma based on bioinformatics analysis

“…The PI3K/Akt pathway is vital to NPC progression, metastasis, and invasion [54]. After the EBV genome is introduced into the NPC cells, this pathway could be activated [55]. A study showed that inhibiting the PI3K/Akt pathway could suppress NPC cell metastasis by inducing mesenchymal-epithelial reverting transition [56].…”

­ Comprehensive analysis of key genes associated with ceRNA networks in nasopharyngeal carcinoma based on bioinformatics analysis

“…The PI3K/Akt pathway is vital to NPC progression, metastasis, and invasion [52]. After the EBV genome is introduced into the NPC cells, this pathway could be activated [53]. A study showed that inhibiting the PI3K/Akt pathway could suppress NPC cell metastasis by inducing mesenchymal-epithelial reverting transition [54].…”

Signaling pathways of EBV-induced oncogenesis

“…The JAK/STAT signaling pathway was significantly inhibited, whereas the NF-κB and PI3K/AKT signaling pathways were enhanced in HONE1 cells. The direct effect on cells can be illustrated by enhanced cell proliferation and migration, accelerated cell cycle progression, and inhibited cell apoptosis [ 72 ]. A comprehensive examination of various signaling pathways could be helpful for making correct decisions regarding treatment.…”