Cytotrophoblasts (from term placentae) and cells from the choriocarcinoma cell line JAr were cultivated either separately or in co-culture for 72 h. RNA was isolated from the cell cultures and Northern blots were developed using equal amounts of RNA. The RNA was hybridized with cDNA probes for CG alpha, CG beta and hPL. Corresponding m-RNAs were detected in the three RNAs except for hPL m-RNA which was absent from JAr cells RNA. The abundance of CG alpha and CG beta m-RNA in the RNA of the co-culture was higher than their accumulative abundances in the RNAs from cytotrophoblasts and JAr cells cultured alone and the abundance of hPL m-RNA in the RNA of the co-cultures was as high as that in the RNA from cytotrophoblasts cultured alone. On the basis of previous findings (Hochberg et al, 1991), it can be assumed that the cytotrophoblasts in the co-cultures are responsible for the increase in hormonal m-RNA production. It could be calculated that the abundances of the CG alpha, CG beta and hPL m-RNAs in the RNA which originated in the cytotrophoblast nuclei were 20, 100 and 10-fold higher respectively in the co-culture compared to those in the culture of cytotrophoblasts. This effect is limited to certain genes only as the concentration of the 92kD collagenase m-RNA and uPA (urokinase type plasminogen activator) m-RNA, which are both produced in cytotrophoblasts to a much higher extent than in JAr cells, and are not increased by cultivating the cytotrophoblasts with JAr cells in co-culture.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Communication↗

PubMedDate not supplied

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 with regard to cellular kinetics and morphologic changes during cell-cell interaction in an in vitro model of trophoblastic neoplasia. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Cell Communication↗