Figure 4.

DDX11 depletion induces G1 phase arrest in HCC cells. (A) GSEA based on TCGA data indicated that in cases with high expression of DDX11, pathways involved in cell cycle regulation were activated or suppressed. (B) Cells with DDX11 knockdown by shRNA were stained with PI and subjected to cytometry analyses to indicate the alteration of cell cycle. The percentages of cells at each cell cycle or under apoptosis were shown. (C) The expressions of factors contributing to cell cycle regulation, such as p53, MDM2, p21, cyclin E, cyclin D1, and phosphorylated Rb were determined by western blot, in cells with DDX11 silence or overexpression. (D) Stable HepG2 and PLC8024 cells were transfected with p21 siRNA for 36 h. The expression of p21 and DDX11 was determined. (E, F) The effect of p21 on DDX11-mediated G1 phase arrest and cell growth suppression was examined by rescue experiments. Stable cells with DDX11 silence and/or p21 knockdown were subjected to cytometry analyses (E) and colony formation (F). *P < 0.05.