Figure 5
From: MDM2 expression in EBV-infected nasopharyngeal carcinoma cells
(a) Enhancement of EBV-LMP1 on p53 activation of mdm2 promoter in NPC-TW06 cells by cotransfection experiment. Lane 1: pGL2-mdm2-Luc plus pGL3-SV40-p53 null; lane 2: pGL2-mdm2-Luc plus pcDNA3.1; lane 3: pGL2-mdm2-Luc plus pcDNA3.1-CMV-LMP1; lane 4: pGL2-mdm2-Luc plus pGL3-SV40-p53; lane 5: pGL2-mdm2-Luc plus pGL3-SV40-p53 plus pcDNA3.1-CMV-LMP1. Lanes 1–3 show only backgound luciferase activity; lane 4 shows an increased luciferase activity (2.6 ×) higher than lane 1; lane 5 reveals a stronger luciferase activity (6.5 ×) higher than lane 1. (b) Comparison of the effect of cotransfection of different plasmids in mt- and wt- p53 NPC cell lines. Lanes 1 and 2: NPC-TW 06 with p53 heterozygous point mutation; lanes 3 and 4: NPC-TW 04 with wt p53. Lanes 1 and 3: pGL2-mdm2-Luc plus pcDNA3.1 were cotransfected into NPC-TW 06 and 04 separately; lanes 2 and 4: pGL2-mdm2-Luc plus pcDNA3.1-CMV-LMP1 were cotransfected into NPC-TW 06 and 04 separately. Lanes 1 and 2 shows only background luciferase activity; lane 3 reveals an increase of luciferase activity (2.2-fold) higher than lane 1; lane 4 shows a stronger luciferase activity (6.3-fold) than lane 1. (c) Investigation of the effect of LMP2A transfection. Lanes 1 and 3: NPC-TW 06 and 04 were cotransfected with pGL2-mdm2-Luc plus pRc/CMV separately; lanes 2 and 4: NPC-TW 06 and 04 were cotransfected with pGL2-mdm2-Luc+pRc/CMV-LMP2A separately. Both lanes 1 and 2 show background luciferase activity in p53 mt NPC-TW 06 line. But in NPC-TW 04 (containing wild type p53), in lanes 3 and 4, both lanes show similar luciferase activity higher than the background level due to endogenous p53 activation; LMP2A does not upregulate endogenous p53 gene to activate more mdm2-luciferase activity.
