Establishment of a visible peritoneal micrometastatic model from a gastric adenocarcinoma cell line by green fluorescent protein.

To establish a visible peritoneal micrometastatic model, an enhanced green fluorescent protein (EGFP) expressing plasmid vector was transfected into the gastric cancer cell line, MKN-45. Highly expressing EGFP cells were injected into the peritoneal cavity of nude mice. Then, the peritoneum and abdominal organs were harvested and observed on days 1, 4 and 7. Fluorescence stereomicroscopy identified peritoneal micrometastases that had been undetected by stereomicroscopy. Micrometastases as small as a single cell are detectable in this model. This peritoneal micrometastatic model should be a useful tool for research on metastasis of gastric cancer.