Brain and cancer: the protective role of erythropoietin

Erythropoietin (Epo) is a pleiotropic agent, that is to say, it can act on several cell types indifferent ways. An independent system Epo/Epo receptor (EpoR) was detected in brain, leading tothe hypothesis that this hormone could be involved in cerebral functions. Epo/EpoR expressionchanges during ontogenesis, thus indicating the importance of this system in neurodevelopment.Moreover, the hypoxia-induced production of Epo in the adult brain suggests that it could exert aneurotrophic and neuroprotective effect in case of brain injury. Epo could also influence neuro-transmission, inducing neurotransmitters (NT) release. Epo therapy in anemic cancer patients isstill a controversial issue, because of its possible action as a growth and an angiogenic factor. In ourspeculative hypothesis Epo could be involved in a ‘‘two steps process’’ that, after a neo-vascularization phase, leads to its down regulation. Moreover, Epo-activated signaling pathwayscould be modulated as possible targets to interfere in neoplastic cells cycle. In conclusion,treatment with rHuEpo could change therapeutical perspectives in different pathological condi-tions, such as central nervous system (CNS) diseases, but further studies are needed to clarify itsphysiopathological activities in different clinical fields.