Emodin and DHA increase sensitivity of HTLV-1–transformed cell lines to As₂O₃ ± IFN-α treatment. (A) HTLV-1–transformed cells (C8166, MT-2) and IL-2–dependent immortalized cells 1185 and LAF were treated with buffer control, 1 μM As₂O₃/IFN-α (100 U/mL), As₂O₃/IFN-α with 10 μM emodin and DHA (AIDE) for 60 hours, and cellular proliferation was measured using the XTT assay. Results are representative of 3 independent experiments performed in duplicate. (B) Proliferation assay of HTLV-I–transformed C8166 cells treated with increasing amounts of emodin and DHA from 10 to 50μM. (C) Proliferation assay of HTLV-I–transformed C8166 cells treated with increasing amounts of emodin and DHA from 1 to 50 μM in the presence of 1 μM As₂O₃/IFN-α. (D) Proliferation assay of normal PBMCs treated with increasing amounts of emodin and DHA from 1 to 50 μM in the presence of 1 μM As₂O₃/IFN-α. (E) Proliferation assay of HTLV-I–transformed C8166 cells treated with 10 μM emodin and DHA, IFN-α (100 U/mL) and decreasing amounts of As₂O₃, 1 μM, 0.1 μM, and 0.01 μM. (F) Comparison of CEM, Jurkat, and LAF proliferation following treatment with As₂O₃/IFN-α and emodin/DHA. Error bars represent SD.