A novel model for invasion of cancer cells using the submucosal layer of the human stomach

An in vitro model for studying the invasion mechanism of cancer cells was established using the submucosal layer of the human stomach. Submucosa prepared from a surgical specimen was maintained in an organ culture. The cytoarchitecture of the cultured submucosa remained well preserved; viability remained for over 2 weeks. When human gastric cancer cell lines MKN45, MKN74, and Kato III were seeded onto the submucosal slices, cancer cells of MKN45 and KATO III invaded the submucosa 3 days after inoculation. However, MKN74 cells were not seen in the submucosal slices. Our invasion model, which mimics the in vivo conditions of the submucosa of human stomach, may make it possible to analyze actual events of human gastrointestinal malignant cell invasion in normal submucosa in vitro. The usefulness of our invasion model lies in the choice of the submucosal layer of the human stomach as the host tissue. The histarchitecture of the submucosal slices indicates that the model has potential for studies of the mechanism of interactions between carcinoma cells and host tissue similar to interactions that may occur in vivo. Moreover, this method allows the continuous microscopic observation of cells within the living submucosa. Using this model, a novel approach to controlling the local invasion of tumor cells may lead to a promising, radical cure for these intractable neoplasms. Our model system is an in vitro model that is facile, inexpensive, and experimentally manipulative.