Figure 2. Cells exhibit increased fold changes in IC₅₀ concentrations following long-term exposure to cisplatin.

Following maintenance of cisplatin treated sublines in culture for 6 months with cisplatin, IC₅₀ concentrations were re-assessed for each cell line using dose-response curves generated by GraphPad Prism software. A significant increase in IC₅₀ concentration was determined for each cisplatin resistant cell line relative to that for the corresponding age-matched parental cell line.