[Dynamics of the spreading of normal and transformed hamster cells].

Morphological peculiarities of spreading studied by scanning electron microscopy in two lines of transformed hamster fibroblasts (HETR and HEC--40) were compared to the normal hamster embryo fibroblasts (NHG). The surface of spherical not streading cells was of a mixed type microrelief (small blebs and microvilli). In transformed cells, the microvillous component was more developed than in their normal counterparts. During cell spreading distinct differences were observed between normal and transformed cells in their cell surface contact interaction with solid substratum. NHF cells formed a well-developed concentrically disposed thin lamelloplasm, while HEC-40 cells had asimmetrically disposed lamelloplasm in combination with long filopodia and HETR cells had a rather thick lamelloplasm consisting of several fragments (often forming star-like pattern). At the polarization stage of spreading neither HETR nor HEC-40 reached the same degree of spreading and flattening as NHF. Moreover, the dorsal surface of transformed cells had a complex microrelief in contrast to a rather smooth surface of NHF. These results are discussed in connection with earlier results on spreading of normal and transformed mouse fibroblasts.