Figure 2

Honokiol inhibits migration and invasion of breast cancer cells. (a) MCF7 and MDA-MB-231 cells were subjected to scratch-migration assay. Culture media were replaced with media containing honokiol (2.5 μM) or untreated media (U). The 100-ng/ml epidermal growth factor (EGF) treatment was used as positive control. The plates were photographed at the identical location of the initial image (0 hours) at 24 hours. The results shown are representative of three independent experiments performed in triplicate. The histogram shows the fold change in migration. *P < 0.01, compared with untreated controls. (b) MCF7 and MDA-MB-231 cells were subjected to spheroid-migration assay. Culture media were replaced with media containing honokiol (2.5 μM) or untreated media (U). The spheroids were photographed 48 hours after treatment. The results shown are representative of three independent experiments performed in triplicate. The histograms show percentage migration. *P < 0.01, compared with untreated controls. (c) MCF7 and MDA-MB-231 cells were cultured in Matrigel invasion chambers followed by treatment with honokiol (HNK, 1.0, 2.5 μM) for 24 hours, as indicated. U, untreated controls. The number of cells that invaded through the Matrigel was counted in five different regions. The slides were blinded to remove counting bias. The histograms show the mean of three independent experiments performed in triplicate. *P < 0.005, compared with untreated controls. (d) Breast cancer cells (MDA-MB-231) were treated with honokiol (HNK, 2.5 μM) for indicated time intervals. U, untreated cells. Total protein was isolated, and equal amounts of proteins were resolved with SDS-PAGE and subjected to immunoblot analysis by using specific antibodies for phosphorylated FAK. The membranes were reblotted by using total FAK antibodies as controls. The blots are representative of multiple independent experiments.