Knockout of fibronectin expression in GBM cell lines inhibited proliferation and migration, increased sensitivity to apoptosis induced by temozolomide in vitro, and markedly suppressed GBM tumor growth and promoted animal survival.
Western blot analysis, the reverse transcription-quantitative polymerase chain reaction, immunohistochemistry, apoptosis assays and immunofluorescence were employed to examine the effects of tunicamycin on apoptosis, viability, aggressiveness and cell cycle arrest of glioblastoma cells by downregulation of the expression levels of fibronectin and epithelial cadherin.
Further, TGF-β induced EDA+FN and EDB+FN in human cerebral microvascular endothelial cells and glioblastoma-derived endothelial cells in a SMAD3- and SMAD4-dependent manner.
Overexpression of fibronectin is strongly associated with the perivascular regions of glioblastoma multiforme and plays a critical role in migrating and invasive glioma cells.
Pep-1 was used to overcome the blood-brain tumor barrier (BBTB) and home to glioma cells via interleukin-13 receptor-α2-mediated endocytosis, and CREKA was used to bind to fibrin-fibronectin complexes abundantly expressed in tumor microenvironment for enhanced retention in the GBM.
Here, it is demonstrated that the invasive phenotype of glioblastoma multiforme is orchestrated by the transcription factor NF-κB which, via metalloproteinases (MMP), regulates fibronectin processing.
In addition, the expression of integrin αV and its strong ligand FN was prominently increased in glioblastomas developed from mouse intracranial GIC xenografts.
The ability of KCC009 to interfere with the permissive remodeling of fibronectin in the ECM in glioblastomas suggests a novel target to enhance sensitivity to chemotherapy directed not only at the tumor mass, but also invading glioblastoma cells.
The levels of fibronectin (FN) and GFAP mRNA of ten human glioblastoma cell lines, determined by Northern blot hybridization of RNA, were related to other phenotypic characteristics [cell morphology and expression of the genes encoding platelet-derived growth factor (PDGF) receptors].