Measurement of tumor growth in vivo

All procedures involving animals were conducted in accordance with the institutional animal welfare guidelines of the Chung Shan Medical University. 5–6 weeks old immuno-deficient nude mice (BALB/c nu/nu mice) were used for the xenograft model. OCSC (1 × 10⁴ cells/0.2 mL/mouse) were injected subcutaneously into the right axilla and the day of cell implantation was designated as day 0. Mice were randomly divided into two groups and fed with either saline (control) or GMI (150 μg/day/kg) by oral gavage 8 days post implantation. Tumor size measurement was performed using an IVIS50 animal imaging system (Xenogen Corp.). The volume was calculated (according to the following formula: [length Χ width²]/2), and then analyzed by Image-Pro Plus software. After 20 days, animals were euthanized followed by tissue excision for phosphor-Stat3 analysis.