Immortalization of Neural Cells with the c-myc and N-myc Proto-oncogenes

The c-myc and the N-myc proto-oncogenes were employed to immortalize neural progenitor cells. Infection of neural precursors isolated from the mouse at the 10th day of embryonic development (E10) with myc-containing retroviruses resulted in immortalized cell lines representing bipotential E10 neuroepithelial cells. These cell lines have the capacity to differentiate into both glial and neuronal cells either spontaneously in the case of the Zen(myc) cell lines or after addition of fibroblast growth factor to the Dol(myc) cell lines. Infection of migrating neural crest cells with the myc retroviruses gave rise to three different types of immortalized cell lines: (i) cell lines resembling freshly isolated neural crest cells; (ii) cell lines that can differentiate into cells expressing Schwann cell markers when grown at high cell concentrations; and (iii) cell lines that have the ability to differentiate in culture to process-bearing cells which expressed neuronal markers or have the characteristics of Schwann cells. Olfactory epithelial cell lines were generated by infection with Zen retrovirus bearing the N-myc proto-oncogene. Some of the cell lines resemble basal cells and others grow as bipolar cells resembling neurons and expressing the neuronal marker neurofilaments.