Objective To explore the effect of activin A on the migration and adhesion of murine breast cancer 4T1 cells.

Methods The viability of in vitro cultured 4T1 cells was studied using the 3- (4,5-dimethyl-2-thiazyl)-2,5-diphenyl-2h-tetrazolium bromide (MTT) assay. Scratch assay was conducted to evaluate the wound healing capacity of 4T1 cells. The ability of adhesion of 4T1 cells was detected by real time cell analysis (RTCA). The microfluidic chip-based cell patterning was used to assay 4T1 cells migration.

Results  MTT assay results showed that the optical density (OD) values of culture medium of 4T1 cells of control group, treated with activin A of 1.25, 5, and 20 (ng/mL) for 24 hours were 0.47 ± 0.01, 0.53 ± 0.006, 0.63 ± 0.02, and 0.66 ± 0.02 and those treated for 48 hours were 0.63 ± 0.04, 0.68 ± 0.01, 0.75 ± 0.03, and 0.85 ± 0.03, respectively, indicating significantly increased viability of 4T1 cells treated with activin A of 5 and 20 ng/mL (P < 0.01 for all). Significantly difference was observed in percentage of migration area between 4T1 cells of control (18.3 ± 2.15%) and those treated with activin A (37.0 ± 1.44%) in scratch-wounded test (P < 0.01). The microfluidic observation showed that the number of migrated cells per vision field was 16 ± 3 for 4T1 cells treated with 20 ng/mL activin A for 12 hours, significantly higher than that (8 ± 2) of control cells in microfluidic chip-based cell patterning (P < 0.01). RTCA showed a significant difference in cell index between control 4T1 cells and the 4T1 cells treated with 20 ng/mL activin A for 8 hours (1.06 ± 0.12 vs. 1.43 ± 0.05, P < 0.01).

Conclusion In summary, activin A promotes not only viability, but also migration and adhesion of murine breast cancer 4T1 cells, which may play an important role in metastasis of breast cancer cells.