IL8 increases cellular invasive potentials. (A) Transwell migration (left) and invasion (right) assays of MCF10A and MCF10ATw cells towards 20% horse serum for 24 h. MCF10ATw cells were treated as indicated. α-IL8 Ab, IL8 neutralizing antibody, 10 μg/ml; SB225002, 10 nM; Repertaxin, 400 μM; n.s. not significant. Mean±SD, n = 3, *P ≤ 0.1, **P ≤ 0.05. (B) Proliferation assays for MCF10A, MCF10ATw and MCF10ATw cells cultured as indicated with conditions described in (A) for 24 h. Mean±SD, n = 3. (C) Representative images of cells from transwell migration and invasion experiments described in (A). Scale bar, 160 μm. (D) Gelatin zymography assays of conditioned media collected from MCF10A, MCF10ATw or MCF10ATw cell cultures treated with indicated compounds for 24 h. SB225002, 100 nM; Repertaxin, 400 nM. (E) Transwell invasion assays (left) of BT549 cells towards 20% fetal bovine serum for 24 h. Cells were stably transduced with control shRNAs (shCtrl1, shCtrl2), shRNA against IL8 (shIL8) or TWIST1 (shTw). Mean ± SD, n = 3, **P ≤ 0.05. Representative images (right) of BT549 cells that invaded through Matrigel. Scale bar, 160 μm. (F) Proliferation assays (24 h) for BT549 cells stably transduced with shCtrls, or shRNA against IL8 (shIL8) or TWIST1 (shTw) under conditions described in (E). Mean±SD, n = 3.