Fig. 2

Accelerated tumor cell migration and invasion by KLK6 silencing. (A) Representative pictures of FaDu-Mock and FaDu-shKLK6 clones demonstrating a mesenchymal-like morphology (upper panel) after silencing of KLK6 expression accompanied by the presence of stress fibers as determined by phalloidin IF staining (signal in green). Nuclear staining was done with Hoechst 33324 (blue staining); black bar = 50 μm and white bar = 50 μm. (B) Representative bright-field pictures of FaDu-Mock and FaDu-shKLK6 clones at the indicated time points of an in vitro migration assay. Red lines indicate the border of the migration front. Black bar = 500 μm. (C) Differences in tumor cell migration between FaDu-Mock and FaDu-shKLK6 clones is depicted as relative mean values ± SD of three independent experiments. Gap closure was determined by quantification of open areas between two borders at the indicated time points, and the value at the time point 0h was set to 100 %. (D) Representative pictures of invasive FaDu-Mock and FaDu-shKLK6 clones in a matrigel-coated Boyden chamber assay after nuclear staining with Hoechst 33324 (blue staining); white bar = 50 μm. (E) Quantification of the total amount of invading cells is depicted as mean value ± SD of three independent experiments