Figure 5

Inhibition of CXCR4 signaling decreases hMSC stimulated MCF-7 proliferation and migration in vitro. (A) MCF-7 cells cultured alone were treated with DMSO (control) or SDF-1 (50 ng/ml) for 72 hours. Cells were fixed and stained with anti-Ki-67 (red) and nuclei were counter stained with DAPI (blue). Representative images of MCF-7 cells at 200×. (B) Quantification of cells positive for Ki-67 staining from 10 fields of view per treatment. Data is represented as percent positive cells of total cells counted. Bars represent mean values ± SEM. (C) MCF-7 cells were seeded in the lower chamber of a 24-well plate and a transwell insert was placed in each well. MCF-7 cells or hMSCs were seeded in the upper well. Upper and lower chambers were treated with DMSO (control) or AMD3100 (5 μg/ml). After 7 days of culture, inserts were removed and MTT was added to each well. After 4 hours cells were lysed and absorbance read. All data are represented as mean percent proliferation as compared to MCF-7 + DMSO (control) treated cells ± SEM. (D) MCF-7-GFP cells alone or in combination with hMSCs (1:1) were seeded in the upper chamber of a transwell system where the lower wells contained culture media supplemented with 10% FBS (10%). Upper and lower chambers were treated with DMSO (control) or AMD3100 (5 μg/ml). After 48 hours cells were fixed and the number of GFP-positive migrated cells counted. Bars represent average number of migrated cell per condition ± SEM, (*, p < 0.05; **, p < 0.01).