Cell proliferation and protooncogene induction in oligodendroglial progenitors

Publisher Website
Google Scholar
Abstract
Cell proliferation and the expression of the protoon‐cogenes c‐fos and c‐jun have been examined in the primary cultures of oligodendroglial (OL) progenitor cells in response to phorbol 12‐myristate 13‐acetate (PMA), serum, insulin, insulin‐like growth factor‐I (IGF‐I), platelet‐derived growth factor (PDGF), and fibroblast growth factor (FGF). Combined [3H]thymidine autoradiography and immunocytochemistry was used to asses the mitogenic response of O4 (an oligodendrocyte‐specific marker)‐positive OL progenitors. In addition, the rate of DNA synthesis was measured by the incorporation of [3H]thymidine into acid‐precipitable material. It was found that all of the agents tested stimulated DNA synthesis in OL progenitors and induced a rapid increase in c‐fos and c‐jun protooncogene expression. The induction of c‐fos gene expression and DNA synthesis in response to PMA was completely blocked by 1‐(5‐isoquinolinyl‐sulfonyl)‐2‐methylpiperazine (H‐7), a potent inhibitor of protein kinase C (PKC), thereby suggesting a role for PKC in the control of c‐fos expression and cell proliferation in OL progenitors.