siRNA silencing of AKT represses the proliferation and mitosis of HaCaT cells. Following the transfection of HaCaT cells with AKT-specific siRNA, the expression of AKT mRNA and protein was analyzed using (A) reverse transcription-quantitative polymerase chain reaction and (B) western blotting analyses, respectively. (C) The proliferation of HaCaT cells was determined at 12, 24, 36 and 48 h following transfection using a BrdU assay. (D) The percentage of mitotic HaCaT cells were determined at 10, 12, 14, 16 and 18 h following transfection. *P<0.05, **P<0.01 vs. the siRNA control group; miR, microRNA; AKT, protein kinase B; siRNA, small interfering RNA.