Figure 4.
Glutamate antagonists alter tumor cell morphology and decrease tumor cell motility. Scanning electron micrographs of thyroid carcinoma cells (FTC238) under control conditions (A) and after exposure to dizocilpine (B, 100 μM) or GYKI52466 (C, 100 μM). Tumor cells display numerous pseudopodia (A), which are far less prominent after exposure to glutamate antagonists (B and C). (D) Protrusion of tumor cell pseudopodia of FTC238 cells through the 0.4-μm pores of a polycarbonate filter are shown under control conditions. After exposure to dizocilpine (100 μM) or GYKI52466 (100 μM), protrusion of cell pseudopodia was nearly absent. (E) Glutamate antagonists decrease migration of A549, TE671, and FTC238 cells. The 1 × 105 cells were placed on the upper chambers of 12-well transwells (polycarbonate filter with 3-μm pore size) and allowed to grow for 96 h alone or in the presence of dizocilpine (25 μM) or GYKI52466 (25 μM). The cells, which migrated into the lower chamber through the 3-μm pores of the polycarbonate filter, were counted. Results represent mean ± SEM of six measurements. **, P < 0.01; ***, P < 0.001 vs. control, Student's t test. (Scale bars = 10 μm in A–C and 5 μm in D.)