Abstract
Colon cancer is a common malignancy worldwide and there is an urgent requirement to develop effective treatment strategies. In recent years, tumor immunotherapy has become a new method of effectively treating tumors. Chimeric antigen receptor (CAR) T cell technology combines the precise targeting specificity of monoclonal antibodies with the strong toxicity and persistence of cytotoxic T cells to specifically recognize tumor‑associated antigens and promote tumor cell death efficiently and permanently, without depending on major histocompatibility complex restriction. In the present study, epithelial cell adhesion molecule (EpCAM)‑targeting CAR T cells (EpCAM‑CAR‑T) were developed, and their ability to kill cancer cells in vitro was assessed. Firstly, an EpCAM‑CAR plasmid was constructed using molecular biology techniques, and transfected into T cells to obtain EpCAM‑CAR‑T cells. Transfection efficiency was assessed using reverse transcription‑quantitative PCR and flow cytometry. Next, the expression levels of EpCAM in five colon cancer cell lines were examined by western blotting and flow cytometry. Finally, the effect of EpCAM‑CAR‑T cells on cancer cell death was examined in vitro via co‑culture experiments. T cells stably expressing EpCAM‑CAR were successfully obtained, and the transduction efficiency according to flow cytometry was 50.4%. In vitro experiments showed that EpCAM‑CAR‑T cells exhibited a significantly higher apoptotic effect on cancer cells compared with untransfected T cells. Analyses also demonstrated that this effect was dependent on the ratio of EpCAM‑CAR‑T cells to tumor cells, and the expression of surface EpCAM. Similarly, the ELISA results showed that interleukin (IL)‑2 IL‑6 and interferon‑γ levels were significantly elevated following exposure to EpCAM‑CAR‑T cells compared to exposure to untransfected T cells, and were dependent on the number of EpCAM‑CAR‑T cells and the amount of EpCAM expressed on the surface of tumor cells. The present study provided a basis for the clinical application of CAR‑T cell therapy against solid tumors, and a provided a new strategy for the treatment of colon cancer.