Chronic Exposure to the Tumor Promoter TPA Mimics Differentiating Effects of Serum in Primary Cultures of Cerebellar Granules

We investigated the effect of tumor promoter TPA on the differentiation of cerebellar granule cells in vitro. Cells chronically treated with nanomolar concentrations of TPA fully attain terminal differentiation in serum-free media. Neuronal features induced by TPA are similar to those induced by serum which is considered essential for survival and maturation of granule cells. The possible role of protein kinase C., the major phorbol ester receptor, in mediating the differentiating effect of TPA is discussed.