Altogether, these results show that AurA, a well-known kinase of the mitotic machinery, may play alternative roles in human glioblastoma according to the CXCL12 concentration.
Our results demonstrate that (i) GSCs located in the SVZ are specifically resistant to radiation in vivo, (ii) these cells display enhanced mesenchymal roots that are known to be associated with cancer radioresistance, (iii) these mesenchymal traits are specifically upregulated by CXCL12 (stromal cell-derived factor-1) both in vitro and in the SVZ environment, (iv) the amount of SVZ-released CXCL12 mediates GBM resistance to radiation in vitro, and (v) interferes with the CXCL12/CXCR4 signalling system, allowing weakening of the tumor mesenchymal roots and radiosensitizing SVZ-nested GBM cells.
Exogenous administration of CXCL12 rescues the drug-induced decrease in proliferation.<b>Conclusions:</b> This study demonstrates that the CXCL12/CXCR4 axis operates in glioblastoma cells under hypoxic stress via an autocrine-positive feedback mechanism, which promotes survival and cell-cycle progression.
The CXCL12/CXCR4 pathway is upregulated in the glioblastoma tumor microenvironment regulating tumor cell proliferation, local invasion, angiogenesis, and the efficacy of radio-chemotherapy.
The chemokine CXCL12 (also termed SDF-1, stromal cell-derived factor-1) and its receptors CXCR4 and CXCR7 are known to play a pivotal role in tumor progression including glioblastomas (GBM).
Engineering NK Cells Modified With an EGFRvIII-specific Chimeric Antigen Receptor to Overexpress CXCR4 Improves Immunotherapy of CXCL12/SDF-1α-secreting Glioblastoma.
Importantly, CXCL12 inhibited TRAIL activation of the apoptotic pathway in GBM, suggesting that AT-MSCs may support GBM development in vivo by at least two distinct mechanisms-promoting angiogenesis and inhibiting apoptosis.
In fact the signaling pathways involved in the pro-migratory action of CXCL12 may differ in individual glioblastoma and integrate with those resulting from abnormal expression and activation of growth factor receptors.
The SDF-1 3'A genetic variation is correlated with elevated intra-tumor tissue and circulating concentration of CXCL12 in glial tumors: a study on Iranian anaplastic astrocytoma and glioblastoma multiforme patients.
In addition, we demonstrate that the extracellular signal-regulated kinase (ERK)1/2 pathway is only partially implicated in the modulation of CXCL12-induced glioblastoma cell movement, whereas the phosphoinositol-3 kinase (PI3K) pathway is not involved.
In the present study, we demonstrate that CXC chemokine receptor 4 (CXCR4) is expressed in human glioblastoma U251 cell line, and that SDF-1 alpha increases the proliferation, chemotaxis, and invasion in CXCR4+ glioblastoma U251 cells through the activation of ERK1/2 and Akt.
However, the high expressions of CXCR4 and CXCL12 in glioblastomas, the more invasive astrocytomas, suggest a different role of CXCL12/CXCR4 signaling axis in astrocytoma progression.
We previously demonstrated that stromal cell-derived factor 1 (SDF1) exerts a mitogenic activity in glioblastomas through the activation of its receptor CXCR4.
We previously demonstrated that astrocytes and glioblastoma cells express both the chemokine receptor CXCR4 and its ligand stromal cell-derived factor-1 (SDF-1), and that SDF-1alpha treatment induced cell proliferation, supporting the hypothesis that chemokines may play an important role in tumor cells' growth in vitro.