Figure 7.

miR-200 s and their targets Fli-1 and TCF12 promote breast cancer cell invasion in ECM. CAFs expressing vectors encoding miR-200 s were grown in a Col-I gel for 10 days and then treated with detergent extraction. MDA-MB-231 breast cancer cells were seeded onto the Col-I gel and cultured for 5 days. The architecture of the paraffin-embedded Col-I gel was visualized by PR staining, and the invasive cells in the ECM gel were visualized by H&E staining; representative images are shown (Scale bars, 100 μm). (a–c) Matrices derived from the indicated fibroblasts were analyzed by PR staining for collagen deposition and orientation. (d–f) MDA-MB-231 cell invasion in the Col-I gel that was remodeled by the indicated fibroblasts. (g) MDA-MB-231 cell invasion in the Col-I gel that was remodeled by the indicated CAFs was determined after ectopically expressing Fli-1 in CAF/miR-200c cells or TCF12 in CAF/miR-141 cells. (h) MDA-MB-231 cell invasion in the Col-I gel that was remodeled by the indicated NFs was investigated after knocking down Fli-1 and miR-200c or TCF12 and miR-141 expression using specific shRNAs