Screening of gastric cancer cell sublines using the adhesion method

OBJECTIVE: To screen subpopulations of gastric cancer cell lines with different malignant phenotypes. METHODS: Two subpopulations from the human gastric cancer cell line MKN-45 were separated by using the laminin adhesion method. One subpopulation was less invasive and non-metastatic, whereas the other was more invasive and metastatic. The relative invasiveness and migratory capacities of the two subgroups were observed by using the Boyden chamber and by inoculating the cells into nude mice. RESULTS: The two subgroups, the laminin-adherent cells (Lm+) and the laminin non-adherent cells (Lm–), were separated. During in vitro experiments, the Lm+ cells were more invasive and their migratory ability was greater relative to the Lm– cells. The rates of tumor formation after subcutaneous inoculation in nude mice and of lung tumor foci formation after tail vein inoculation were higher in Lm+ cells than those in Lm– cells. In vivo, Lm+ cells were found to have higher metastatic potential and to be more invasive. CONCLUSIONS: In vitro, the adhesion method is a simple and time-saving way to screen a particular phenotypic cell subpopulation with a high success rate. There are discrepancies in invasiveness and migratory ability between in vitro Lm+ and Lm– cells, which suggests that these properties of gastric cancer cells are closely related to their adhesiveness to the basement membrane and extracellular matrix.