Figure 5.

Glutamate antagonists enhance antiproliferative effect of cytostatic drugs. Cyclophosphamide (CPM; 1.5 mM) and thiotepa (100 μM) decreased viability of TE671 and SKNAS cells as measured by means of the MTT assay. The effect of cyclophosphamide and thiotepa on viability of TE671 and SKNAS cells was enhanced by dizocilpine (100 μM) and GYKI52466 (100 μM). Tumor cells were incubated for 96 h in culture medium (control) and with either cytostatic drug in the absence or presence of glutamate antagonists. Decrease of cell viability by the cytostatic drug in control cultures was set as 100% (dotted line). Enhancement of cytostatic effect by glutamate antagonists is expressed as % of the cell viability decrease achieved with the cytostatic drug alone. Bars represent mean increase of cytostatic effect expressed in percentage ± SEM (n = 6). ***, P < 0.001 vs. cytostatic drug alone, Student's t test.