mediated #Alpelisib randurls[1|1|,|CHEM1|]# knockdown of HDAC8 UCCs were seeded in 6-well plates and grown for 24 h before transfection. Cells were transfected with 10 nM HDAC8 Silencer® Select validated siRNA (#4390824, s31698, Ambion, Life Technologies, Darmstadt, Germany) or a Silencer® Select Negative Control #2 validated siRNA (#4390846, Ambion, Life Technologies, Darmstadt, Germany) using Lipofectamine RNAi MAX (Invitrogen, Life Technologies, Darmstadt, Germany), according to the manufacturer’s protocol. After transfection cells were incubated for 72 h before use for further experiments. Determination of mean inhibitory concentrations (IC50) and viability The mean inhibitory concentrations (IC50) and cell viability were measured trough total cellular ATP as an indicator for viable cells using the CellTiter-Glo® Luminescent Cell Viability Assay (Promega, Mannheim, Germany). UCCs were seeded into 96-well plates and grown for 24 h before inhibitor treatment with the indicated drug click here concentration or DMSO and further grown for 72 h. In another experiment, cells were plated in 6-well plates and grown for 24 h before siRNA-mediated knockdown of HDAC8. Viability measurements were performed after 72 h by transferring the cells into 96-well plates using CellTiter-Glo Reagent according
to manufacturer’s protocol in a Wallac Victor 1420 Multilabel Counter (PerkinElmer, Rodgau, Germany). Colony forming assay and Giemsa-staining The colony forming assay was carried out 72 h after siRNA mediated HDAC8 knockdown and HDAC8 inhibitor treatment. Then, cells were plated in 6-well plates at a density of 500 to 1,000 cells per well. After 10 days, cells were washed with PBS (Biochrom, Merck Millipore, Berlin, Germany), shortly fixed in 50% methanol and incubated for 10 min in 100% methanol. The colonies were
stained with Giemsa (Merck, Darmstadt, Germany). Colony number and size was determined with ImageJ software (http://rsbweb.nih.gov/ij/). Cell cycle analysis by flow cytometry UCCs were transfected with HDAC8 siRNA or an irrelevant control siRNA or, in another experiment, cultured with the determined IC50 concentrations of the HDAC8 selective inhibitors c2, c5 and c6, the pan HDAC-inhibitor SAHA (2.5 μM) or DMSO. Cell cycle analysis was performed after 72 h by staining the attached cells and cells in the supernatant with a PI-buffer containing Janus kinase (JAK) 50 μg/ml propidium iodide, 0.1% sodium citrate and 0.1% Triton X-100  and flow cytometry using a BD LSR Fortessa cell analyzer system and FACSDiva software 6.2 (Becton Dickinson Biosciences, Heidelberg, Germany). Migration assay Cell migration was determined in wound healing assays by means of Ibidi Culture-Insert (Ibidi, Martinsried, Germany). The cell suspension was placed in both compartments allowing growth in the designated area only. The cells were treated with IC50 concentrations of c2, c5, c6 or 2.5 μM SAHA 48 h prior to plating.