Fig. 3

SUSD4 is involved in cell migration and invasion. To determine the role of SUSD4 in breast cancer, several functional assays were preformed. The growth assay showed no difference between SUSD4a- and mock- transfected MDA-MB-231 (a), while the SUSD4a-transfected BT20 cells grew slower after 72 hours (f). The ability of cancer cells to adhere to matrigel was not affected by SUSD4a (b, g), but the protein could influence migration. Random migration was decreased in BT20 cells expressing SUSD4a after 3 hours (h), but not in MDA-MB-231 cells (c). SUSD4a decreased both directed migration (d, i), along a gradient of serum, and invasion through a layer of matrigel (e, j) in both tested cell lines. The data represents at least three independent experiments ± SD. SUSD4a was compared to mock by 2-way ANOVA with Bonferroni post-test (a, c, f, h), or unpaired Student’s t-test (b, d, e, g, i, j). The symbols ns, *, **, and *** stand for not significant, p < 0.05, p < 0.01, and p < 0.001