Figure 2.

Treatment with auranofin (AF) selectively induces apoptosis of cultured and primary CLL CD19⁺ cells independent of cytogenetics or IGHV mutation status, despite coculture with NLCs and reduced in vivo leukemia burden. A, IC₅₀ values for the primary CLL patient cells treated with auranofin for 24 hours subgrouped by IGHV mutational (U, unmutated; M, mutated) status. Black line, median IC₅₀ value. B, IC₅₀ values for primary CLL patient cells treated with auranofin for 24 hours subgrouped by ZAP70 status. Black line, median IC₅₀ value. C, cell viability of primary CLL cells from patients subgrouped by ZAP70 status (ZAP70⁺n = 12; ZAP70⁻n = 15) following treatment with the indicated concentrations of auranofin for 24 hours. Each point on the line represents the mean viability of the CLL cells at each concentration of auranofin; bars, SEM. *, cell viability values significantly less in ZAP70⁺ auranofin-treated cells than ZAP70⁻ auranofin-treated cells (P < 0.05). D, percent apoptosis of MEC-1 cells and CD19⁺ primary CLL cells (11q deleted, 13q deleted, and 17p deleted) exposed to the indicated doses of auranofin for 48 hours. *, apoptosis values significantly greater in 17p-deleted CLL than in 11q- and 13q-deleted CLL cells at 0.25 µmol/L of auranofin (P < 0.05). **, apoptosis values significantly greater in 17p-deleted CLL than in 11q-and 13q-deleted CLL cells at 0.5 µmol/L of auranofin (P < 0.05). E, the percentage of sub-G₁ cells and percentage of Annexin V-positive, apoptotic MEC-1 cells following 24-hour exposure to auranofin. Immunoblot analyses were also conducted as indicated. F, IC₅₀ values for the primary CLL patient cells treated with auranofin for 24 hours, subgrouped by adverse (ADV) or favorable (FAV) cytogenetics. Black line, median IC₅₀ value. G, percent apoptosis of MEC-1 cells with and without coculture on HK cells following treatment with auranofin for 48 hours. *, values significantly less in MEC-1 cells cocultured with HK cells compared with MEC-1 without coculture (P < 0.05). H, primary CLL cells (n = 4) were cultured with or without NLCs and exposed to two times the IC₅₀ of auranofin for 24 hours. At the end of treatment, the percentage of nonviable cells was determined by flow cytometry. The absolute viability of the CLL cells in each condition is shown. I, treatment of TCL-1 mice (n = 5) with auranofin (10 mg/kg, 5 days per week for 2 weeks) significantly reduced the leukemia cell burden. Columns represent the mean ± SEM of the leukemia cell burden in all 5 mice tested. J, Kaplan-Meier survival plot of TCL-1 mice treated with auranofin compared with untreated mice. (P = 0.001, log-rank (Mantel-Cox) test.