Pharmacological Substances

In total, 5 different pharmacological substances were tested in the experiments. All of them were obtained as powders from LC Laboratories (Woburn, MA, USA), except of erufosine, which was synthesized by Prof. Hans-Joerg Eibl (Max Planck Institute for Biophysical Chemistry, Goettingen, Germany). By dissolving in dimethyl sulfoxide (DMSO; Merck Millipore, Burlington, MA, USA), solutions of different concentrations (see below) of erlotinib, selumetinib, trametinib and everolimus were established and stored at 4°C until further utilization. Erufosine was dissolved in phosphate-buffered saline (PBS; Biochrom AG, Berlin, Germany).