Long-term exposure to relaxin decreases cell motility and in vitro invasiveness. (a) MDA/RLN2 and MDA/EGFP transfectants were subjected to motility assays as described for Figure 2. (b) In contrast to a 24-hour short-term exposure, long-term incubation of MDA-MB-231 cells with 500 ng/ml rhRLN for eight days did not cause changes in cellular motility with the number of migrated cells remaining unchanged when compared with controls (medium). Experiments were performed in triplicates and five microscopic fields were counted for each filter. The results are shown in the graph as mean ± SEM. (a, b) One-way ANOVA analysis was performed. **p < 0.005 when different from (a) MDA/EGFP or (b) medium treatment. MDA/RLN2 and MDA/EGFP transfectants were seeded on 8 μm porous filters coated with (c) collagen A and (d) laminin to assess in vitro invasiveness. Experiments were assessed as described for motility assays. The results of three independent experiments are shown in the graph as mean ± SEM. One-way ANOVA analysis was performed. **p < 0.005 when different from MDA/EGFP control.