In summary, these findings highlight a key role for PI3K/mTOR signalling in GLI1 regulation in HH-driven cancers and suggest that combined PI3Kα/mTOR inhibition may be particularly interesting for the development of effective treatment strategies in high-risk medulloblastomas.
IMPLICATIONS: These findings raise the possibility of a unique therapeutic approach for medulloblastoma, involving MNK targeting to sensitize medulloblastoma CSCs to PI3Kα inhibition.
Therefore, we investigated the anti-MB efficacies of combined HH inhibitor Vismodegib and PI3K-mTOR dual-inhibitor BEZ235 together or combined individually with cisplatin against high-risk MB.
These results suggest that LncRNA LOXL1-AS1 promoted the proliferation and metastasis of medulloblastoma by activating the PI3K-AKT pathway, providing evidence that knockdown of LncRNA LOXL1-AS1 might be a potential therapeutic strategy against medulloblastoma.
In this context, we demonstrate that the clinically available PI3K inhibitor GDC-0941 enhances the anti-neoplastic efficacy of Axitinib against c-myc-amplified medulloblastoma.
The data from the present study suggest that TRIM59 induces epithelial-to-mesenchymal transition and promotes migration and invasion by PI3K/AKT signaling pathway in medulloblastoma.
Our findings therefore provide a rational to further evaluate Vandetanib in combination with PI3K inhibitors as well as standard chemotherapeutics in vivo for the treatment of most aggressive medulloblastoma variants.
Together, these data reveal a novel molecular signaling network, in which PI3K isoform p110α controls the expression of LIFRα via c-Myc and miR-125b to promote MB cell proliferation.
The mitogen-activated protein kinase (MAPK) pathway, but not the phosphoinositide 3-kinase (PI3K)-Akt pathway, was downregulated in medulloblastoma cells, whereas the PI3K-Akt pathway, but not the MAPK pathway, was downregulated in glioblastoma cells.
We evaluated the distribution and extent of SSR1 and SSR2 expression and correlated it with activation of downstream MEK1-p44/42 MAPK and PI3K-Akt-mTOR pathways in medulloblastomas and PNETs.
Medulloblastoma cells treated with p110alpha inhibitors further displayed reduced activation of Akt and the ribosomal protein S6 kinase in response to stimulation with hepatocyte growth factor and insulin-like growth factor-I.
To examine a role for PI3K/AKT signaling in the molecular pathogenesis of human medulloblastoma, we did an immunohistochemical study of the expression of Ser473-phosphorylated (p)-AKT protein in 22 medulloblastoma samples: All samples displayed p-AKT expression.
A total of 13 mutations of PIK3CA within these specific domains were identified in anaplastic oligodendrogliomas, anaplastic astrocytomas, glioblastoma multiforme, and medulloblastomas, whereas no mutations were identified in ependymomas or low-grade astrocytomas.