(A)
GPX2 mRNA expression in human bladder cell lines, RT4, T24, 5637, and TCCSUP, was assessed by qRT-PCR. The mRNA expression level of GPX2 in RT4 cells, established from low grade UC, was significantly higher than in other cell lines established from invasive high grade UC. Mean ± SD; ****p<0.0001. (B) mRNA expression level of GPX2 in RT4 cells was confirmed by qRT-PCR 2 days after transfection with two different GPX2-targeting and negative control (NC) siRNAs. Mean ± SD; ****p<0.0001. (C) Western blotting analyses at five days after siRNA transfection of RT4 cells. The expression of GPX2 was reduced, but that of cdc25B, cyclin D1, cyclin B, caspase 7, and caspase 3 were not changed. β-actin was used as internal loading control. (D) Proliferation rate of RT4 cells following transfection with GPX2-targeting and NC siRNAs. Mean ± SD; ****p<0.0001. (E) Guava® apoptosis analysis of RT4 cells after siRNA transfection shows that GPX2 knock-down induced apoptosis. Mean; ****p<0.0001. (F) DCFH-DA assay was used to quantify intracellular ROS levels after knock-down of GPX2 by siRNA in RT4 cells. Mean ± SD; ****p<0.0001.