Non-invasive imaging of engineered human tumors in the living chicken embryo

The growing interest in engineered tumor models prompted us to devise a method for the non-invasive assessment of such models. Here, we report on bioluminescence imaging (BLI) for the assessment of engineered tumor models in the fertilized chicken egg, i.e, chick chorioallantoic membrane (CAM) assay. One prostate cancer (PC-3) and two osteosarcoma (MG63 and HOS) cell lines were modified with luciferase reporter genes. To create engineered tumors, these cell lines were seeded either onto basement membrane extract (BME) or gelfoam scaffolds, and subsequently grafted in vivo onto the CAM. BLI enabled non-invasive, specific detection of the engineered tumors on the CAM in the living chicken embryo. Further, BLI permitted daily, quantitative monitoring of the engineered tumors over the course of up to 7 days. Data showed that an extracellular matrix (ECM) composed of BME supported growth of reporter gene marked PC-3 tumors but did not support MG63 or HOS tumor growth. However, MG63 tumors engineered on the collagen-based gelfoam ECM showed a temporal proliferation burst in MG63 tumors. Together, the data demonstrated imaging of engineered human cancer models in living chicken embryos. The combination of CAM assay and BLI holds significant potential for the examination of a broad range of engineered tumor models.