Establishment of Schwann cell lines by oncogene transfer

Schwann cell cultures prepared from murine sciatic nerves (MuSN), rat sciatic nerves (RSN) and murine dorsal root ganglia (MuDRG) were transformed by the introduction of oncogenes (v-arc, c-Ha-ras, and v-mos). The transformation was carried out by infection with helper-free retroviruses containing the oncogene and the neomycin-resistant gene which were produced in psi-2 cells. After G418 selection and cloning of cells showing spindle shape morphology, six different transformed cell clones, i.e., MuSN-arc, MuDRG-arc, MuDRG-ras, MuDRG-mos, RSN-arc, and RSN-mos, were established. All of the clones were labeled with antibodies to the S-100 protein and the laminin, which are specific markers for Schwann cells. Fibronectin and vimentin were not detected in these cell clones, in contrast to fibroblasts as 3T3 and Rat-2. These cell clones have been maintained with characteristics of Schwann cells for over 18 months. When RSN-mos, one of the Schwann cell clones, and rat retinas were cocultured direct cellular interaction was demonstrated. Furthermore, by the addition of conditioned medium of the RSN-mos, a prominent activity promoting neurite outgrowth in PC12 pheochromocytoma cells was observed.