FIG. 3.
Strategy for the establishment of MTXr HT1080 cells. Cells were plated at 5 × 105 per 15-cm-diameter plate and either left untreated or treated with one of the following: 54 μM PALA for 48 h, 2 μM VP16 for 1 h, 10 μM VP16 for 1 h, 10 μM araC for 4 h, or 10 μM araC for 16 h. After treatment, plates were split 1:4 and cells were allowed to recover in normal medium for 1 to 4 days. After recovery, cells were split 1:2 and selected with either 50 or 100 nM MTX. The selective medium was changed every 3 days.