Figure 1.

(A) Growth curves of HAC-15 cells during long-term treatment with mitotane vs untreated control. Every 3–4 days, cells were treated with 70 µM mitotane in on-off cycles. The total number of population doublings (cumulative population doublings; cPD) is indicated. During long-term treatment, cells initially died, but the population recovered after approximately 30 days. (B) IC₅₀ of mitotane in 12 clones derived from long-term treated HAC-15 cells vs 6 control clones measured by MTT assay after 72 h of incubation. Results are shown in scatter dot plots with mean ± s.d. ***, P < 0.001 (Mann–Whitney test).