Growth factor receptors and medulloblastoma.

Growth factors and their receptors play important roles in the regulation of cell division, development and differentiation. Neurotrophins are growth factors which have not been shown, until recently, to be associated with human neoplasia. Medulloblastoma is a central nervous system tumor which is thought to arise from the external granule cell layer of the cerebellum. Platelet Derived Growth Factor (PDGF) or Epidermal Growth Factor (EGF) and/or their receptors have not been found to have a significant role in the development of this tumor. Neurotrophins, however, which regulate cerebellar development in a time-dependent manner, appear to be important in medulloblastoma and the presence of high levels of TrkC expression, a neurotrophin receptor, is associated with a better outcome. The potential role of these growth factors and their receptors in manipulating the behavior of this tumor is discussed.