Orthotopic mouse xenograft model, imaging, and drug administration

Animal studies were performed as previously described⁵⁷ and were approved by University of Florida Institutional Animal Care and Use Committee. Briefly, luciferase-expressing MDA-MB-231 cells were transduced with lentiviral vector containing either scramble (control) or JAB1 shRNA. Transduced cells were then injected into 4th left mammary fat pad of 5-week-old female nude mice (Jackson Lab, Bar Harbor, ME) at 3 × 10⁶ cells per mouse (5 mice each group) and tumor outgrowth was monitored weekly by measuring fluorescence in Xenogen IVIS-200 In Vivo imaging system (PerkinElmer Inc, Waltham, MA) for 4 weeks. In a parallel group, luciferase-expressing MDA-MB-231 cells were similarly injected. After 5 days of tumor cell injections, mice were randomized into two groups (5 per group) and treated daily with either vehicle or 1 µmol/kg of SB203580 i.p. for 4 weeks. Tumor growth were monitored weekly though Xenogen IVIS-200 in vivo imaging system.