EBNA۱ Upregulates P۵۳-Inhibiting Genes in Burkitt's Lymphoma Cell Line

Background: Suppression of p۵۳ is an important mechanism in Epstein-Barr virus associate-tumors and described as EBNA۱-USP۷ which is a key axis in p۵۳ suppression. Thus, in this study, we aimed to evaluate the function of EBNA۱ on the expression of p۵۳-inhibiting genes including HDAC-۱, MDM۲, MDM۴, Sirt-۳, and PSMD۱۰ and the influence of USP۷ inhibition using GNE-۶۷۷۶ on p۵۳ at protein/mRNA level. Methods:  The electroporation method was used to transfect the BL۲۸ cell line with EBNA۱. Cells with stable EBNA۱ expression were selected by Hygromycin B treatment. The expression of seven genes, including PSMD۱۰, HDAC-۱, USP۷, MDM۲, P۵۳, Sirt-۳, and MDM۴, was evaluated using a real-time PCR assay. For evaluating the effects of USP۷ inhibition, the cells were treated with GNE-۶۷۷۶; after ۲۴ hours and ۴ days, the cells were collected and again expression of interest genes was evaluated. Results: MDM۲ (P=۰.۰۲۸), MDM۴ (P=۰.۰۲۸), USP۷ (P=۰.۰۲۸), and HDAC۱ (P=۰.۰۱۵) all showed significantly higher expression in EBNA۱-harboring cells compared to control plasmid transfected cells, while p۵۳ mRNA expression was only marginally downregulated in EBNA۱ harboring cells (P=۰.۶۸۵). Four-day after treatment, none of the studied genes was significantly changed. Also, in the first ۲۴-hour after treatment, mRNA expression of p۵۳ was downregulated (P=۰.۶۸۵), but after ۴ days it was upregulated (P=۰.۷) insignificantly. Conclusions: It seems that EBNA۱ could strongly upregulate p۵۳-inhibiting genes including HDAC۱, MDM۲, MDM۴, and USP۷. Moreover, it appears that the effects of USP۷ suppression on p۵۳ at protein/mRNA level depend on the cell nature; however, further research is needed.

کلیدواژه ها:

Keywords: Epstein-Barr virus ، EBNA۱ ، P۵۳ ، USP۷ ، P۵۳-inhibiting Genes.