Malignant
astrocytomas are able to invade neighboring and distant areas of the normal brain. Signaling pathway alterations play important role in the development of
astrocytomas. Deregulation of eukaryotic translation
initiation factor 4E (
eIF4E) by MAP
kinase-interacting
kinases (Mnk) on Ser-209 directly or PI3K/mTOR/S6K pathway indirectly has a critical effect on promoting cellular proliferation, malignant transformation and
metastasis. We examined and analyzed the correlation between expression of p-Mnk1, p-eIF4E and p-p70S6K
proteins and clinicopathological features in 103
astrocytomas and 54 non-tumorous brain tissues. The results indicated that positive percentage of overexpression of p-Mnk1 and p-eIF4E
proteins in
astrocytomas were significantly higher than that of in the non-tumorous brain tissues (P < 0.05). Elevated p-Mnk1 and p-eIF4E and co-overexpressed three
proteins were associated with
tumor recurrence (P = 0.003, P = 0.006, P = 0.007, respectively). Overexpressed p-eIF4E significantly correlated with the
tumor size (P = 0.019). In addition, overexpression of p-eIF4E and three
proteins common expression were related to the WHO grade of
astrocytomas (P = 0.001, P = 0.044 respectively). Spearman's rank correlation test further showed that the expression of p-Mnk1 was strongly positive correlated with the expression of p-eIF4E in
astrocytomas (r = 0.294, P = 0.003). Besides, overexpression of p-eIF4E and co-expression of p-Mnk1, p-eIF4E and p-p70S6K
proteins were inversely correlated with overall survival rates of
astrocytomas. Multivariate Cox regression analysis further identified that the elevated p-eIF4E expression, three
proteins common expression were correlated with unfavorable prognosis of
astrocytomas regardless of ages and WHO grades. Taken together, overexpression of p-eIF4E and co-expression of p-Mnk1, p-eIF4E and p-p70S6K
proteins could be used as novel independent poor prognostic
biomarkers for patients with
astrocytomas.