CXCL12 increases cell motility dependent from the ECM.

<p>(a) Cells that were attached to different ECM components were observed for one hour using time-lapse video microscopy. The length of their moving path was determined using a cell tracking software (Cell∧D®). (b) MDA-MB-231 and (c) MDA-MB-468 cells showed different patterns of chemokine stimulated motility (□ unstimulated; ▪ 25ng/ml; ///50ng/ml; ≡ 100ng/ml CXCL12). Highly metastatic MDA-MB-231 cells were more motile at CI and LN (*p<0.001) with a concentration-dependent stimulation (+p<0.05) of their motility that was not observed at FN. In contrast, low-metastatic MDA-MB-468 cells were less motile at C I and LN, but showed a concentration-dependent stimulation at FN. (d) In CXCR4-knock-down cells (MDA-MB-231-27) these CXCL12-dependent stimulating effects were not found. The results are shown as mean ± SD for three independent experiments. For statistical analysis ECM dependent migration was compared for all three ECM components and concentration dependence of CXCL12 was compared to unstimulated cells. Significances for ECM dependent cell motility are not marked for improved readability.