Fig. 3.

Aly regulates cell cycle progression and cell proliferation. (A) Aly knockdown alters the expression of cell cycle regulators. HeLa cells were transfected with a control scrambled RNA or Aly siRNA and incubated for 48 h. The cell lysate was separated by SDS/PAGE and analyzed by immunoblotting. Cyclin A2 and cyclin B1 protein expression levels were selectively decreased. (B). siAly inhibits S phase progression. HeLa cells were transfected with control or siAly and incubated for 4 days. Cells were treated with BrdU (20 μM) for 1 h at 37°C and then fixed by 3% formaldehyde. The fixed cells were treated with 2 M HCl and neutralized by boric acid (pH 8.4); cells were analyzed by immunostaining analysis against BrdU antibody. Depletion of Aly decreases BrdU incorporation. Results are expressed as mean ± SEM from three independent experiments. (C) Aly knockdown prevents cell proliferation. Twenty-four hours after transfection, HeLa cells were split into six-well dishes (5 × 10⁴) and incubated for 5 days. After cells were fixed by 3% formaldehyde, cells were stained with crystal violet solution. (D) Ablation of Aly decreases cell growth. (E) Knockdown of Aly decreases mRNA export. Results are expressed as mean ± SEM from three independent experiments (P < 0.005, Student's t test).