Figure 4.

Enhancement of FUdR cytotoxicity in HeLa cells and in FUdR-resistant variants by antisense ODN 83. Cells were treated with antisense ODN 83 or scrambled control ODN 32 for 4 h, followed immediately by coincubation with FUdR for 4 days. Proliferation was determined by increase in cell number. IC₅₀ values were interpolated from plotted data, from a series of experiments represented by Figure 3. The value presented is the IC₅₀ of the ODN 83-treated cells as a percentage of that of the control ODN 32-treated cells, calculated within individual experiments. All values for relative resistance are significantly different from that of control ODN-treated cells, P<0.001. ^aThis value is reproduced from Table 1 (see table for s.d. and n values for these averages). Resistance index was calculated by dividing the IC₅₀ of the FUdR-resistant line by that of the parent HeLa cell line, within each individual experiment. ^bRelative proliferation is the relative increase in cell number, as a percentage of the control ODN-treated cells, of the cultures treated with antisense ODN 83 alone.