A Biomimicking Tumor Tissue Model Using Hepatocellular Carcinoma Cell Sheet in a Collagen Sandwich System

Cytotoxic efficacy of anticancer drugs has been widely studied with monolayer-cultured cancer cells. However, the drug efficacy under two-dimensional (2D) culture conditions usually differs from that of three-dimensional (3D) culture conditions. In the present study, an in vitro tumor tissue model was constructed by sandwiching a cancer cell monolayer (cancer cell sheet) between two collagen layers as a biomimicking tumor tissue model, and the in vitro cytotoxic efficacy of doxorubicin was investigated. In the biomimicking tumor tissue model, hypoxic areas were observed, and the secretion of vascular endothelial growth factor increased time-dependently. Additionally, cell growth inside the model was significantly slower than that of the 2D culture system. The in vitro cytotoxicity of doxorubicin with the 3D system decreased compared to the 2D system, suggesting that the surrounding collagen layer acted as a barrier much like cancer stroma does. Consequently, this study successfully demonstrated that the cancer cell sheet in collagen sandwich configuration provides a useful in vitro tumor tissue model.