Fig. 2.
Naamidine A (NA)-induced G1 cell cycle arrest. (a) Fluorescence-activated cell sorter (FACS) cell cycle analysis after NA treatment of A431 cells for 12 h. When treated with 30 μmol/l NA, an increase in percentage of cells in the G1 phase of the cell cycle occurs with a concomitant withdrawal of cells in the S phase. The t-test statistical analysis was used to compare the changes in percentage G1 and percentage S phase populations to untreated control cells, which yielded a P ≤ 0.005 (*). (b) Western blot analysis of cell cycle inhibitor p21waf1/cip1 protein expression levels after NA (30 μmol/l) or epidermal growth factor (EGF) (2 nmol/l) treatment. Induction of p21 protein levels occurs within 1 h of NA treatment with maximum induction after 2 h. Full-length western blots are presented in Supplemental Figure S1.