Fig 2: The NF-?B pathway inhibitor abrogates the promotive role of LMP1 for lymphoma cell growth and p53 degradation. (A) The proliferation ability of KHYG-1 and SNT-8 cells evaluated by EdU staining; (B) Cell viability after CFSE staining determined by flow cytometry; (C) Cell cycle distribution detected by flow cytometry; (D) Cell apoptosis level assessed by flow cytometry; (E) Ubiquitination of p53 in KHYG-1 and SNT-8 cells detected by Co-IP. The data was performed as means ± SD of three independent experiments. One-way ANOVA was used to compare the mean of samples among multiple groups, followed by Tukey’s multiple comparisons test. The data was performed as means ± SD of three independent experiments. *p < 0.05, **p < 0.01 vs. the LMP1 + DMSO group; #p < 0.05, ##p < 0.01 vs. the shLMP1 + DMSO group.

Fig 3: Specific activation of p53 or inhibition of Bcl-2 inhibits the LMP1 action on lymphoma cell viability and apoptosis. (A) Bcl-2 expression in KHYG-1 cells and p53 expression in SNT-8 cells determined by Western blot; (B) The proliferation ability of KHYG-1 and SNT-8 cells evaluated by EdU staining; (C) Cell viability after CFSE staining determined by flow cytometry; (D) Cell cycle distribution detected by flow cytometry; (E) Cell apoptosis level assessed by flow cytometry. The data was performed as means ± SD of three independent experiments. One-way ANOVA was used to compare the mean of samples among multiple groups, followed by Tukey’s multiple comparisons test. *p < 0.05, **p < 0.01 vs. the LMP1 + DMSO group; #p < 0.05, ##p < 0.01 vs. the shLMP1 + DMSO group.

Fig 4: LMP1 activates the NF-?B pathway to induce MDM2-mediated p53 protein degradation. (A) NF-?B p65 phosphorylation levels and p53, MDM2, Bax and Bcl-2 protein expression in cells detected by Western blot (one-way ANOVA was used to compare the mean of samples among multiple groups, followed by Tukey’s multiple comparisons test); (B) MDM2 and p53 binding in KHYG-1 and SNT-8 cells detected by Co-IP; (C) Ubiquitination of p53 in KHYG-1 and SNT-8 cells detected by Co-IP. The data was performed as means ± SD of three independent experiments. *p < 0.05, **p < 0.01 vs. the Lv-NC group; #p < 0.05, ##p < 0.01 vs. the Scr group.

Fig 5: MG132 significantly attenuates the action of LMP1 on lymphoma cell growth and p53 degradation. (A) Ubiquitination of p53 in KHYG-1 cells detected by Co-IP; (B) The proliferation ability of KHYG-1 cells evaluated by EdU staining; (C) Cell viability after CFSE staining determined by flow cytometry; (D) Cell cycle distribution detected by flow cytometry; (E) Cell apoptosis level assessed by flow cytometry. The data was performed as means ± SD of three independent experiments. Unpaired t-test was applied to compare the mean of samples between groups. The data was performed as means ± SD of three independent experiments. *p < 0.05, **p < 0.01 vs. the LMP1 + DMSO group.