Figure 1.

Effect of PLK1 inhibitor BI2536 in nine different squamous cell carcinoma cell lines versus untreated control. Growth inhibitory effect of the single agent BI2536 at a fixed cell line-specific concentration of 2.5 nmol/l after 72 h in nine different squamous carcinoma cell lines (black columns) is shown. The corresponding untreated tumor cell lines (grey columns) served as controls and were incubated according to the instructions of the suppliers with antibiotics at 37°C in the cell type-specific medium Quantum 263 with L-glutamine. The number of absolute tumor cells in the treated and control cell lines was determined in a Rosenthal chamber at 72 h after treatment or incubation with Quantum 263 (controls), respectively. The mean values of three independent experiments with standard deviation are shown. Single agent differences versus untreated controls are indicated by asterisks. BI2536 inhibited cell proliferation significantly in all nine cell lines treated (p<0.009 versus controls for all nine cell lines).