[Invasion of spheroid aggregate of mouse lung adenocarcinoma (LA 795) cells into embryonic chick heart fragments].

An in vitro invasion model of tumor cell spheroid aggregate was established by using mouse lung adenocarcinoma cell line (LA795) and precultured embryonic chick heart fragments (PHF). The spheroid aggregates of LA795 cells were prepared by incubating a suspension of trypsinized LA795 cells on a gyratory shaker. Spheroid aggregates of LA795 cells in diameter of 0.2 mm were selected and confronted with PHF (diameter of 0.4 mm) on semisolid medium for 3-4 hours, then, individual confronting pairs were transferred into fluid medium for further co-culture on gyratory shaker. After 1, 3, 5 and 7 days, multiplicated confronting pairs were processed for histological and ultrastructural study. The invasive capacity and the invasion process of LA795 cells were examined. The results demonstrated that LA795 cell line has a high capacity of invasion and malignancy in vitro. This spheroid invasion model is very useful for studying invasiveness of tumor cells in vitro.