Improved in vivo subcutaneous tumor generation by cancer cell sheet transplantation

Abstract

Background/Aim: In vivo subcutaneous tumor models are generally prepared by the injection of a cancer cell suspension to evaluate the pharmaceutical effects on tumor tissues. However, dispersed cells show low biological activities because of enzyme-induced cell harvest treatment, thus limiting the formation of tumor tissues. In this study, a biologically active cancer cell monolayer (cell sheet) was used to improve the efficiency of subcutaneous tumor formation. Materials and Methods: Mouse lung squamous cancer cells (KLN-205) were transplanted on the subcutis of immunocompetent and immunodeficient mice in the form of a dispersed cell suspension or cell sheet, and the tumor formation abilities were independently investigated with considering immunological effects. Results: Mouse lung squamous cancer cells (KLN-205) scarcely formed malignant tumors on the mouse subcutis following injection of the cell suspension. On the other hand, cell transplantation in the cell sheet form successfully achieved effective tumor development due to only weak immunological reactions at the transplanted area. And thus, the cancer cells maintained their proliferative activity to form tumors. Conclusion: Transplantation of the cell sheet is effective to generate subcutaneous tumor-bearing mice, providing a useful alternative to the low tumor formation activities induced with the conventional injection method.