Proliferation and clonogenicity in urothelial cancer cells after siRNA mediated knockdown of HDAC8. (A) Relative cell viability in several urothelial carcinoma cell lines after siRNA mediated knockdown of HDAC8 compared to irrelevant control (72 h). The percentage of viable cells was measured by ATP-assay and is displayed on the y-axis. p < 0.01 and p < 0.001 were defined as highly significant and marked as * and **. (B) Giemsa-staining of colonies from irrelevant siRNA and HDAC8 siRNA transfected RT-112, VM-CUB1, SW-1710, 639-V and UM-UC-3 cells compared to an untreated control (72 h).