[Effects of surfactin on proliferation, apoptosis and cytoskeleton in human breast cancer MCF-7 cells].

We studied the effect of surfactin on cell proliferation, apoptosis and the cytoskeleton in human breast cancer cell line MCF-7 in vitro. The result of 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) showed that the surfactin inhibited proliferation of MCF-7 cells in a dose- and time-dependent manner, with IC50 at 48 h of 27.3 micromol/L. Surfactin-induced cell death was considered to be apoptotic by observing the typical apoptotic morphological changes by AO/EB staining. Flow cytometric analysis also demonstrated that surfactin caused time-dependent apoptosis of MCF-7 cells through cell arrest at G2/M phase. Immunofluorescence and Western blotting showed that surfactin significantly suppressed the expression of vimentin, induced the alpha-tubulin depolymerization and rearrangement and then the skeleton system of the cells changed dramatically. Based on our findings, surfactin can significantly inhibit the growth of MCF-7 cells and induce apoptosis.