Figure 7

Ectopic expression of cystatin E/M suppresses glioma cell motility and invasion. (a) Scratch wound assay. T98G cells were transfected with empty vector (pcDNA3) or cystatin E/M expression vector (pcDNA3-CST6) and allowed to reach ∼90% confluence over 72 h. The monolayer was then wounded with a plastic pipette tip, washed, and photographed over a period of 24 h. U-87MG cells were not examined because they do not form a tightly packed monolayer. (b) Cell invasion assay. U-87MG cells were transfected with empty vector or cystatin E/M expression vector. After 24 h, cells were replated into the Cultrex cell invasion assay kit (Trevigen), allowed to grow for an additional 24 h then cell invasion was measured and set relative to empty vector transfected cells. Similar results were obtained with T98G cells (data not shown). (c) Western blot demonstrating ectopic expression of cystatin E/M in T98G and U-87MG cells. The breast cancer cell line MDA-MB-231 served as a positive control for cystatin E/M expression. Upper and lower bands (gray and black arrowheads) correspond to the glycosylated and non-glycosylated forms of cystatin E/M, respectively.