Abstract
BACKGROUND: Evaluation of novel drugs for clinical development depends on screening technologies and informative preclinical models. Here we developed a multicolor bioluminescent imaging platform to simultaneously investigate transcription factor NF-κB signaling and apoptosis. METHODS: The human breast cancer cell line (MDA-MB-231) was genetically modified to express green, red and blue light emitting luciferases to monitor cell number and viability, NF-κB promoter activity and to perform specific cell sorting and detection, respectively. The pro-luciferin substrate Z-DEVD-animoluciferin was employed to determine apoptotic caspase 3/7 activity. We used the cell line for the in vitro evaluation of natural compounds and in vivo optical imaging of tumor necrosis factor TNFα-induced NF-κB activation. RESULTS: Celastrol, resveratrol, sulphoraphane and curcumin inhibited the NF-κB promoter activity significantly and in a dose dependent manner. All compounds except resveratrol induced caspase 3/7 dependent apoptosis. Multicolor bioluminescence in vivo imaging allowed the investigation of tumor growth and NF-κB induction in a mouse model of breast cancer. CONCLUSION: Our new method provides an imaging platform for the identification, validation, screening and optimization of compounds acting on NF-κB signaling and apoptosis both in vitro and in vivo.