Activin A (ACVA) is a member of the TGF-β superfamily of cytokines and involved in a wide range of biological processes including tissue morphogenesis and repair, fibrosis, inflammation, neural development, hematopoiesis, reproductive system function, and carcinogenesis. To test the effect of ACVA on cell apoptosis, A549 cells were seeded into 96-well plates at a density of 3,000 cells/well with 1% serum standard DMEM including various concentrations of recombinant human ACVA. After incubated for 48h, cells were observed by inverted microscope and cell proliferation was measured by Cell Counting Kit-8 (CCK-8). Briefly, 10 µL of CCK-8 solution was added to each well of the plate, then the absorbance at 450 nm was measured using a microplate reader after incubating the plate for 2 hours at 37℃. Proliferation of A549 cells after incubation with ACVA for 48h observed by inverted microscope was shown in Figure 1. Cell viability was assessed by CCK-8 (Cell Counting Kit-8 ) assay after incubation with recombinant human ACVA for 48h. The result was shown in Figure 2. It was obvious that ACVA significantly inhibit cell viability of A549 cells. The ED50 is 5.09 μg/mL.

Figure 2. Inhibition of A549 cells proliferation after stimulated with ACVA.