NHERF-1: modulator of glioblastoma cell migration and invasion.
The invasive nature of malignant gliomas is a clinical problem rendering tumors incurable by conventional treatment modalities such as surgery, ionizing radiation, and temozolomide. Na(+)/H(+) exchanger regulatory factor 1 (NHERF-1) is a multifunctional adaptor protein, recruiting cytoplasmic signaling proteins and membrane receptors/transporters into functional complexes. This study revealed that NHERF-1 expression is increased in highly invasive cells that reside in the rim of glioblastoma multiforme (GBM) tumors and that NHERF-1 sustains glioma migration and invasion. Gene expression profiles were evaluated from laser capture-microdissected human GBM cells isolated from patient tumor cores and corresponding invaded white matter regions. The role of NHERF-1 in the migration and dispersion of GBM cell lines was examined by reducing its expression with small-interfering RNA followed by radial migration, three-dimensional collagen dispersion, immunofluorescence, and survival assays. The in situ expression of NHERF-1 protein was restricted to glioma cells and the vascular endothelium, with minimal to no detection in adjacent normal brain tissue. Depletion of NHERF-1 arrested migration and dispersion of glioma cell lines and caused an increase in cell-cell cohesiveness. Glioblastoma multiforme cells with depleted NHERF-1 evidenced a marked decrease in stress fibers, a larger cell size, and a more rounded shape with fewer cellular processes. When NHERF-1 expression was reduced, glioma cells became sensitized to temozolomide treatment resulting in increased apoptosis. Taken together, these results provide the first evidence for NHERF-1 as a participant in the highly invasive phenotype of malignant gliomas and implicate NHERF-1 as a possible therapeutic target for treatment of GBM.
Kislin
Kerri L
KL
Cancer and Cell Biology Division, Translational Genomics Research Institute, Phoenix, AZ 85004, USA.
McDonough
Wendy S
WS
Eschbacher
Jennifer M
JM
Armstrong
Brock A
BA
Berens
Michael E
ME
D015153:Blotting, Western; D001932:Brain Neoplasms / Q000235:genetics / Q000378:metabolism*; D002448:Cell Adhesion / Q000235:genetics; D002465:Cell Movement / Q000235:genetics; D005455:Fluorescent Antibody Technique; D020869:Gene Expression Profiling; D005909:Glioblastoma / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D007834:Lasers; D042282:Microdissection; D009361:Neoplasm Invasiveness / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics / Q000378:metabolism*; D046888:Tissue Array Analysis; D014162:Transfection
D010750:Phosphoproteins; D034741:RNA, Small Interfering; D017923:Sodium-Hydrogen Exchangers; C093376:sodium-hydrogen exchanger regulatory factor