Fig 5. Effect of DNA methylation on PLAT promoter-driven reporter gene activity.

Reporter gene activity of methylated (M) or unmethylated (NM) plasmids was compared after transfection of HeLa cells (top and center) or HT 1080 (bottom) with pCpGLprom401 and pCpGLprom151 plasmids, which contain the PLAT promoter region from -401 to +151 and -151 to +151, respectively, linked to a CpG-less firefly luciferase gene. Note that reporter gene activity of the methylated plasmids was the same as that of reporter gene plasmids lacking a promoter (empty) and markedly reduced compared to unmethylated plasmids. Results are presented as means ± SEM of 3 to 4 independent experiments.