Fig. 5

miR-720 maintains the migratory and invasive properties of MDA-MB-231 cells. MDA-MB-231 cells were transfected with 50 nM anti-miR-720 or anti-miR-negative control (Ctrl) for 48 h. Either RNA was isolated (a) or transfected cells subjected to functional assays (b–e). a miR-720 levels. RNA was subjected to RT-qPCR for miR-720. Control condition (Ctrl) was set to 1.0 (mean ± SD from three independent experiments). b Migration assay. Transfected cells were subjected to a migration assay in a Boyden chamber over a 24-h period. The cells that migrated through the chamber were quantified using crystal violet staining. Ctrl was set to 100 % (mean ± SD from three independent experiments). c Matrigel assay. Transfected cells were grown in Matrigel for 11–15 days and then photographed using a Nikon eclipse TS100 microscope at 10× magnification. Scale bar = 100 μm. Representative images of two independent experiments with similar results are shown (left panels). The number of branched colonies were counted. The count in the control sample was set to 1.0 (right panel). d Transendothelial migration assay. Transfected MDA-MB-231 cells were plated in a Boyden chamber that had been coated with a confluent monolayer of HUVEC cells, and the cancer cells that invaded through the HUVEC layer over a 24-h period were quantified using crystal violet staining. Ctrl value for transendothelial (transendo.) migration was set to 100 % (mean ± SD from three independent experiments) and relative (Rel.) migration values given. e ATP assay. Transfected cells were grown for 24 h and ATP levels were measured using an ATPlite 1Step assay. Ctrl was set to 100 % (mean ± SD from three independent experiments). *P < 0.05, ***P < 0.001, Student’s t test. Not sig. not significant