Figure 6. Overexpression of E2F1 overcame G1 arrest induced by CIP2A siRNA knockdown and upregulated expression of Cdk1 and Cdk2 protein in 16E7-expressing cells.

(A) Western blot analysis of E2F1, Cdk1, Cdk2, cyclin A2, Cdk4, Cdk6 and Cyclin D1 protein levels in RPE1–16E7 cells transfected with CIP2A siRNA, then transfected with pCMV or pCMV-E2F1 plasmid. (B) Flow cytometry of cells treated with/out bleomycin stained with PI. G1, S and G2 phase are indicated.