Transforming growth factor beta 1 or TGF-β1 is a polypeptide member of the transforming growth factor beta superfamily of cytokines. It is a secreted protein that performs many cellular functions, including the control of cell growth, cell proliferation, cell differentiation, and apoptosis. To test the effect of TGF-β1 on cell apoptosis, A549 cells were seeded into 96-well plates at a density of 5,000 cells/well with 1% serum standard DMEM including various concentrations of recombinant mouseTGF-β1. After incubated for 48h, cells were observed by inverted microscope and cell proliferation was measured by Cell Counting Kit-8 (CCK-8). Briefly, 10µL of CCK-8 solution was added to each well of the plate, then the absorbance at 450nm was measured using a microplate reader after incubating the plate for 2 hours at 37℃. Proliferation of A549 cells after incubation with TGF-β1 for 48h observed by inverted microscope was shown in Figure 1. Cell viability was assessed by CCK-8 assay after incubation with recombinant mouse TGF-β1 for 48h. The result was shown in Figure 2. It was obvious that TGF-β1 significantly inhibit cell viability of A549 cells. The ED50 is 7.1μg/mL. (A) A549 cells cultured in DMEM, stimulated with 12.5μg/mL TGF-β1 for 48h;
(B) Unstimulated A549 cells cultured in DMEM for 48h.
Figure. Inhibition of A549 cells proliferation after stimulated with TGF-β1

Figure. Inhibition of A549 cells proliferation after stimulated with TGF-β1.