Morphologic characteristics of the interaction between normal cytotrophoblasts and their malignant counterpart in the development of trophoblastic neoplasia

To define the biology of the tumor-host cell interaction with regard to cellular kinetics and morphologic changes during cell-cell interaction in an in vitro model of trophoblastic neoplasia.

Using a coculture in vitro system of cytotrophoblasts and choriocarcinoma cells, we investigated the cellular kinetics and the morphologic changes in these interacting cells. A fully automatic time-lapse image system was used to record phase contrast images of the cocultured cells in a tissue culture chamber. To examine cytoskeletal structure, immunofluorescent-labeled antibodies against intermediate filaments were used. Slides were examined with a confocal laser scanning microscope and subjected to computed analysis.

The choriocarcinoma cells attract normal cytotrophoblasts using what resembles pseudopodia to engulf the latter cells and thus form slow-growing colonies. In this process, new hybrid cells are formed, which can be differentiated from their original contributors by morphologic characteristics.

This phenomenon supports our previous biochemical and molecular data on the role of cell-cell interaction in the complex process of cytotrophoblast transformation and the development of gestational trophoblastic neoplasia.