Figure 1. p16^INK4a transcription activity increased with cell senescence.

A. Schematic presentation of mutants of GC-boxes in the p16^INK4a promoter. Young (B) and senescent (C) 2BS cells were transfected with 1.6 µg GC-box mutants or pGL3-620 along with 0.32 µg pRL-CMV vectors. 48 hours after transfection, cells were harvested and subjected to luciferase activity assays. The luciferase activity was normalized to Renilla luciferase activity. The data represent the mean.±S.E. of three independent experiments.