Fig 4.

The effects of Notch1 active form ICN1 on cell proliferation and cell cycle arrest. Cells (0.5 ml medium/per well) were plated in 24-well plates and cultured overnight, then transfected with ICN1 or pcDNA (control) and incubated for 5-6 hours. 1.5 ml fresh medium were added and cell were cultured for different time (3 days for cell proliferation, overnight for cell cycle). A, the proliferation assay from three experiments showed that ICN1 induced cell proliferation, with an increase of 9% (ICN1: 200 ng), 18%(400 ng) and 67% (800 ng), respectively. One-way ANOVA showed an significant increase by the dose trend and the highest (Asterisk *) compared to control, with P < 0.01. B, the cell cycle analysis from three experiments showed that ICN1 overexpression induced an increase at phase G1 of cell cycle, with a rate 82.9 ± 0.8% compared to 67.3 ± 1.3% of control, a decrease at phase G2 with a rate 1.7 ± 0.1% (control: 3.9 ± 1.7% and phase S with a rate 15.4 ± 0.9 % (control: 28.8 ± 1.6%).