Journal: Oncology Letters

Article Title: Curcumin increases the sensitivity of K562/DOX cells to doxorubicin by targeting S100 calcium-binding protein A8 and P-glycoprotein

doi: 10.3892/ol.2019.11083

Figure Lengend Snippet: Addition of curcumin enhances apoptosis induced by DOX in K562/DOX cells. (A) Effects of curcumin (2 µM), DOX (4 µM) and si-S100A8 used alone or in combination on the intracellular free calcium ion concentration in K562/DOX cells. Effects of curcumin (2 µM), DOX (4 µM) and si-S100A8 used alone or in combination on the protein expression of (B) Bcl-xL, Bax and (C) CHOP in K562/DOX cells. (D) Effects of curcumin (2 µM), DOX (4 µM) and si-S100A8 used alone or in combination on caspase-3 activity. (E) K562/DOX cells were stained with DAPI after pre-treatment and observed under an inverted fluorescence microscope (magnification, ×40) and the relative fluorescence intensity analysis of DAPI was determined. DNA fragmentation is indicated by red arrows. ***P<0.001. DOX, doxorubicin; K562/DOX, DOX-resistant K562 cell line; S100A8, S100 calcium-binding protein A8; Bcl-xL, B-cell lymphoma extra-large; Bax, Bcl-2-associated X protein; CHOP, CCAAT/enhancer-binding protein homologous protein; si-S100A8, small interfering RNA targeting S100A8.

Article Snippet: Antibodies against P-gp (cat. no. 13342; 1:1,500 dilution) and CCAAT/enhancer-binding protein homologous protein (CHOP; cat. no. 2895; 1:2,000 dilution) were obtained from Cell Signaling Technology, Inc.; anti-S100A8 antibody (cat. no. 15792-1-AP; 1:1,500 dilution) was obtained from ProteinTech Group, Inc., whereas antibodies specific for Bcl extra-large (Bcl-xL; cat. no. bs-5234R; 1:1,000 dilution), Bcl-2-associated X protein (Bax; cat. no. bs-0127R; 1:1,000 dilution) and β-actin (cat. no. bs-0061R; 1:1,000 dilution) were purchased from Bioss Antibodies.

Techniques: Concentration Assay, Expressing, Activity Assay, Staining, Fluorescence, Microscopy, Binding Assay, Small Interfering RNA