Abstract
During the process of X-ray-induced neoplastic transformation of Syrian / golden hamster embryo (SHE) cells, cell morphology altered progressively. While normal SHE cells showed flat and well extended morphology, anchorage-independent clones were slightly refractive and tumorigenic cells became spindle-shaped and highly refractive.
By immunostaining method, we observed that actin microfilaments were well organized in normal SHE cells. Although same pattern still existed in anchorage-independent clones, actin microfilaments completely disappeared in tumorigenic cells. In the case of tubulin fibers, we detected an increment of the number of fibers also in tumorigenic cells. Fibronectin meshwork gradually decreased during the malignant progression of Xirradiated cells. Only vimentin filaments did not altered during the progression of neoplastic transformation.
From western blot analysis, we could not find differences in the amount of actin and tubulin among SHE cells, anchorage-independent clones and tumorigenic cells.
These results suggest that multistep changes of cytoskeletal organization and extracellular matrix cause the stepwise change in cell morphology, and that disappearance of these organization may play a role in the acquisition of tumorigenicity.
