Figure 1.

Cisplatin‐induced programmed death‐ligand 2 (PD‐L2) expression in anti–tumor drug‐resistant HSC‐2 cells. A, HSC‐2 cells were incubated with various concentrations of cisplatin for 0‐72 h. After cisplatin treatment, the number of viable cells was determined by the CCK8 assay. B, Expression of PD‐L2, ABCG2 and ALDH1 genes in HSC‐2 cells with or without cisplatin treatment (2 μmol/L). Samples were analyzed by RT‐PCR. Data shown are the means from seven culture wells (mean ± SEM). * and ** indicate P < 0.05 and P < 0.01, respectively, vs control (0 h). C, Cells were treated without (control) or with cisplatin (2 μmol/L). Flow cytometry analysis used 20 000 cells/each sample. Mouse IgG‐PE (isotype) was used as a negative control. D, The immunocytochemistry expression of PD‐L2 and ABCG2 in cisplatin‐treated HSC‐2 cells was also confirmed. Scale bar = 50 μm. E, Western blotting was conducted using targeted and β‐actin antibodies in membrane and cytoplasm fractions separated from HSC‐2 cells treated with cisplatin for 24 h. Similar results were obtained from three independent experiments