Downregulation of activin A leads to a decrease in proliferation.

<p>Treatment with recombinant activin A was not able to promote proliferation of HaCat cells, as revealed by bromodeoxyuridine (BrdU) incorporation index (A) and cell cycle analysis (B). (C) Follistatin at 100 ng/ml significantly blocked BrdU incorporation in SCC-9 ZsGreen LN-1 cells, but no effects on cell cycle distribution were observed (D). Knockdown of activin A significantly decreased proliferation (E), enhancing the number of cells at G0/G1 and reducing the number in the S phase of cell cycle (F). Bars represent the means ± SD of three independent experiments. *p<0.01, **p<0.001, ***p<0.0001.