Effects of curcumin and dexamethasone. (A) Effect of curcumin and dexamethasone on nuclear localization of NF-κB. Enriched CD138⁺ cells (1 × 10⁵ cells/0.1 mL) from bone marrow aspirates of multiple myeloma patient no. 20 were cultured in the absence or presence of curcumin or dexamethasone (50 μM each) for 2 hours, fixed the cells on slides by cytospin centrifugation, and immunostained for NF-κB, as described in “Patients, materials, and methods.” Original magnification, × 200. (B) Effect of curcumin and dexamethasone on phosphorylation of IκBα. A total of 2 × 10⁶ CD138⁺ multiple myeloma cells were treated with curcumin (50 μM) or dexamethasone (50 μM) for the indicated times, and prepared the cytoplasmic extracts, resolved 30 μg cytoplasmic extracts on 10% SDS-PAGE gel, electrotransferred on a nitrocellulose membrane, and probed for phosphorylated IκBα by Western blot analysis. β-actin was used as a loading control. (C) Enriched CD138⁺ cells (2 × 10⁶ cells) from bone marrow aspirates of multiple myeloma patients were treated with curcumin (50 μM), dexamethasone (50 μM) alone, or in combination for 3 hours and then tested for NF-κB activity in the nuclei by electrophoretic mobility shift assay as described in “Patients, materials, and methods.” (D) Effect of curcumin and dexamethasone on nuclear localization of STAT3. Enriched CD138⁺ cells (1 × 10⁵/0.1 mL) from bone marrow aspirates of multiple myeloma patient no. 20 were cultured in the absence or presence of curcumin or dexamethasone (50 μM each) for 2 hours, then fixed the cells on slides by cytospin centrifugation and immunostained for STAT3, as described in “Patients, materials, and methods.” Original magnification, × 200. (E) Effect of curcumin and dexamethasone on phosphorylation of STAT3. A total of 2 × 10⁶ CD138⁺ multiple myeloma cells were treated with curcumin (50 μM) or dexamethasone (50 μM) for the indicated times, prepared the whole cell extracts, resolved the 30 μg whole cell extracts on 10% SDS-PAGE gel, electrotransferred on a nitrocellulose membrane, and probed for phosphorylated STAT3 by Western blot analysis. STAT3 was used as a loading control.