OBJECTIVETo establish a nude mouse model of orthotopic engineered gastric tumor for in vivo fluorescence imaging studies.

METHODSAn engineered gastric tumor was constructed in vitro using collagen as the scaffold and the human gastric cancer cell line BGC823-EGFP cells expressing enhanced green fluorescence protein (EGFP) as the seed cells. The engineered tumor was then implanted into the stomach of nude mice, and the tumor growth was observed with in vivo fluorescence imaging. The nude mice were sacrificed 6 weeks after the transplantation to assess the tumor growth and metastasis, and the tumor histology was evaluated.

RESULTSThe tumor cells in the engineered tumor model grew well in three-dimensional culture. The success rate of orthotopic gastric tumor implantation was 100% (10/10) in nude mice with metastasis in the abdominal organs. The isolated tumor mass, weighing 1.719∓0.349 g, showed a histological characteristic of poorly differentiated adenocarcinoma. In vivo fluorescence imaging detected EGFP-expressing tumors in the abdominal cavity of the nude mice, but not accurately.

CONCLUSIONThe nude mouse model bearing orthotopic engineered gastric tumor provides a simple animal model for the study of gastric cancer, but a stronger fluorescence than green fluorescence is more desirable for more effective observation in in vivo fluorescence imaging.