Figure 2. NA treatment inhibits U251 cell invasion in vitro.

Transwell assays were carried out for U251 cells incubated in PBS (control) or the indicated concentration of NA as described in Methods. Images of cells (stained with Giemsa) that invaded through the matrigel (A–C) or remained on the seeded side (E–G) in a representative experiment are shown, and results of 15 different regions in 3 independent experiments (5 regions per experiment) are summarized in (D) and H for the opposite and seeded sides, respectively.