Sequential expression of proto-oncogenes during a mouse erythroleukemia cell differentiation.

To investigate the possible involvement of proto-oncogenes in the regulation of cell differentiation and proliferation, their transcriptional levels were measured by Northern blot analysis during the process of dimethyl sulfoxide-induced differentiation of mouse erythroleukemia cells. The differentiation into erythrocytes was accompanied by sequential transient expression of the proto-oncogenes in the order of c-fos, c-myb, c-myc and c-k-ras, during the first 48 hr of differentiation induction. Following the transient expression of these proto-oncogenes, adult type sss-globin and embryonic type yl-globin gene transcripts appeared and accumulated in terminally differentiated cells. The expression of ten other proto-oncogenes examined here were not detected, nor dramatically changed during differentiation process.