Ivis 2000 system

Animal experiments were performed in accordance with the laws and regulations governing animal experiments in the Federal Republic of Germany, following the approval of the respective animals’ ethics committee (Regierungspräsidium Karlsruhe, Germany). Initially, eight animals (6 weeks-old) weighing 120-130 g were bought from Charles River Company (Sulzfeld, Germany). The rats were maintained in ventilated macrolon cages, under controlled conditions (22°C ± 1°C temperature, 55% humidity and 12h dark/light rhythm) in a specific pathogen free animal facility at the German Cancer Research Center (DKFZ). They were allowed unlimited access to a commercial chow and autoclaved tap water ad libitum. Prior to the commencement of any experiment, a seven day window was adhered to, for acclimatization. For tumor implantation, the abdominal cavity was opened under anesthesia (Isoflurane) and ∼3 × 10⁶ cells/animal were injected intraportally (via a mesocolic vein) under the microscope. Wounds were closed by suturing the musculature followed by attaching the edges of the separated skins by surgical wound clips. Tumor growth was monitored on a weekly basis by subcutaneous injection of luciferin (500μl/animal), prior to imaging by IVIS 2000 system (Perkin Elmer, US).