Favourable prognosis in medulloblastoma with extensive nodularity is associated with mitogen-activated protein kinase upregulation.
Medulloblastoma with extensive nodularity (MBEN) is the only type of medulloblastoma (MB), an aggressive CNS tumour of childhood, that is connected with favourable prognosis. In patients with MBEN tumour resection and chemotherapy are sometimes sufficient. While development of other types of MB is usually connected with activation of the wingless pathway, sonic hedgehog pathway or mammalian target of rapamycin (mTor) pathway, little is known about the molecular basis of MBEN pathophysiology. In the present paper we evaluated activation of the mTor pathway and kinases upstream of mTor, mitogen-activated protein kinase (MAPK/Erk) and protein kinase B (PKB/Akt) in an MBEN sample. Using western blot technique with antibodies directed against active, phosphorylated forms of proteins, we found upregulation of mTor, Akt and Erk. Thus we postulate that the mTor pathway, often implicated in the development of CNS tumours, is also responsible for MBEN progression. Especially interesting seems implication of Erk and other kinases belonging to the same pathway: mitogen-activated protein kinase kinase (MEK-1) or phospho-ribosomal S6 kinase-1 (p90 RSK1), whose activity we usually demonstrate in more benign neoplasms. However, it remains to be clarified whether Erk pathway activation is actually prognostic for benign tumour development.
Department of Histology and Embryology, Center for Biostructure Research, Medical University of Warsaw, Poland. jaroslaw.jozwiak@gmail.com
Jarosław
J
Jóźwiak
Iwona
I
Sontowska
Barbara
B
Bikowska
Wiesława
W
Grajkowska
Ryszard
R
Galus
Marcin
M
Roszkowski
D002528:Cerebellar Neoplasms / Q000201:enzymology* / Q000473:pathology; D006801:Humans; D020935:MAP Kinase Signaling System / Q000502:physiology*; D008527:Medulloblastoma / Q000201:enzymology* / Q000473:pathology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010766:Phosphorylation; D011379:Prognosis; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism; D015854:Up-Regulation
D058570:TOR Serine-Threonine Kinases; D020928:Mitogen-Activated Protein Kinases