MORPHOLOGIC CHARACTERISTICS OF THE INTERACTION BETWEEN NORMAL CYTOTROPHOBLASTS AND THEIR MALIGNANT COUNTERPART IN THE DEVELOPMENT OF TROPHOBLASTIC NEOPLASIA

OBJECTIVES: To define the biology of the tumor-host cell interaction w ith regard to cellular kinetics and morphologic changes during cell-ce ll interaction in an in vitro model of trophoblastic neoplasia. METHOD S: Using a coculture in vitro system of cytotrophoblasts and choriocar cinoma cells, we investigated the cellular kinetics and the morphologi c changes in these interacting cells. A fully automatic time-lapse ima ge system was used to record phase contrast images of the cocultural c ells in a tissue culture chamber. To examine cytoskeletal structure, i mmunofluorescent-labeled antibodies against intermediate filaments wer e used. Slides were examined with a confocal laser scanning microscope and subjected to computed analysis. RESULTS: The choriocarcinoma cell s attract normal cytotrophoblasts using what resembles pseudopodia to engulf the latter cells and thus form slow-growing colonies. In this p rocess, new hybrid cells are formed, which can be differentiated from their original contributors by morphologic characteristics. CONCLUSION : This phenomenon supports our previous biochemical and molecular data on the role of cell-cell interaction in the complex process of cytotr ophoblast transformation and the development of gestational trophoblas tic neoplasia.