OBJECTIVETo establish a colon cancer cell line with stable expression of carcinoembryonic antigen(CEA).

METHODSRecombinant lentivirus conjugated with CEACAM5 cDNA were used to transfect wild CT26 cells. Antibiotics were given for 2 weeks to select CEA positive cells. A single transfected clone was obtained using limiting dilution. The 7th and 14th passages of cells cultured in vitro were detected for CEACAM5 mRNA by RT-PCR, and protein by western blot. The location of CEACAM5 expression was examined using fluorescent microscope and immunocytochemistry. The 14th passage cells were injected subcutaneously into mice to create BALB/c model and CEACAM5 protein was detected by in vivo fluorescence image analysis system and immunohistochemistry.

RESULTSCEACAM5 mRNA and protein were found in the 7th and 14th passages of CT26CEA cells, which were proved to locate in the cytoplasm by fluorescence microscope and immunohistochemistry. Abundant CEACAM5 protein was found in subcutaneous tumors by in vivo fluorescence image analysis system and immunohistochemistry.

CONCLUSIONColon cancer cell line CT26 with stable expression of CEA in vitro and in mice can be used as a suitable tool to facilitate research on the impact and mechanism of CEA on colon cancer under normal immune environment.