Fig. 2.

Fetuin-A interacts synergistically with CXCL12 to attract tumor cells. In panel A, chemo-attraction assay was performed as described in Section 2 using the breast carcinoma cell line, BT-549. The lower wells were coated with either 0.3 or 0.5 mg/ml of fetuin-A in SFM overnight at 4 °C, washed and the wells reconstituted with either 500 μl of SFM or CXCL12 (100 ng/ml) in SFM. Other lower wells contained only indicated concentrations of CXCL12 (50–150 ng/ml) in SFM. The BT-549 cells (25,000 cells/well) in 500 μl of SFM were then added to the upper wells and their attraction towards the respective lower wells monitored. The bars represent the means of three separate experiments under the same conditions ± SD (one way ANOVA *P < 0.001). In panel B, the chemo-attraction assay was repeated with increasing concentrations of fetuin-A (0–1 mg/ml) in 500 μl of SFM in the lower wells (open bars). BT-549 cells (25,000 cells/chamber) were added to the upper wells in 500 μl of SFM without (open bars) or containing fetuin-A (0–1 mg/ml) (solid bars). When fetuin-A was in the top wells with cells, the lower wells contained 500 μl of SFM. The bars represent mean number of cells per microscope field of three separate experiments.