Increased microRNA-375 expression impairs extracellular matrix degradation and number of mature invadopodia in UMSCC1 cells. Representative images of fluorescent matrix (A, D), tyrosine kinase substrate with 5 SH3 domains (Tks5) (B, E), and cortactin (C, F) immunostaining for UMSCC1 transductant cells. Arrows in zoomed areas show matrix degradation holes colocalized with Tks5 and cortactin puncta. Quantitation of matrix degradation per cell for UMSCC1 transductant cells (G) shown as mean and standard error of the mean (SEM) of 4 independent experiments; **P=.002. Quantitation of invadopodium precursors and mature invadopodia per cell for UMSCC1 transductant cells (H) shown as mean and SEM of 4 independent experiments; *P=.02 (original magnification × 413 [A through F]; original magnification × 1270 [insets A through F]). Abbreviation: n.s., not significant.