Upregulation of mitogen-activated protein kinase in ganglioglioma.

Ganglioglioma (GG) is a low-grade neoplasm, often associated with intractable epilepsy in pediatric patients. Available data suggest a relationship between GG and other glioneuronal lesions. So far, little is known about activation of kinases belonging to the mTor (mammalian target of rapamycin) pathway, although its upregulation is often found in brain tumors. Involvement of mTor kinase is responsible for excessive proliferation. In the current study we focused on the possible role of the Erk/Mapk (extracellular-signal-regulated kinase/mitogen-activated protein kinase) pathway in GG development. Eight GG tumors were resected from pediatric patients. Collected data reveal activation of proteins from the Erk pathway: Mek (extracellular regulated protein kinase kinase/mitogen-activated protein kinase kinase), Erk, Rsk1 (ribosomal S6 kinase 1), Rheb (Ras homolog enriched in brain) and Msk1 (mitogen- and stress-activated protein kinase 1), as detected by the western blot method. Moreover, activation of other proteins upstream of mTor - IGF-1R β (insulin-like growth factor 1β receptor), INR β (insulin receptor β), Akt/PKB (protein kinase B) - or downstream - 4E-BP1 (eukaryotic translation initiation factor 4E-binding protein 1) and rpS6 (ribosomal protein S6) - was also confirmed.