Ziv-Av A, Giladi ND, Lee HK, Cazacu S, Finniss S, Xiang C, Pauker MH, Barda-Saad M, Poisson L, and Brodie C. RTVP-1 regulates glioma cell migration and invasion via interaction with N-WASP and hnRNPK. Oncotarget 2015; 6(23):19826-19840.
Glioblastoma (GBM) are characterized by increased invasion into the surrounding normal brain tissue. RTVP-1 is highly expressed in GBM and regulates the migration and invasion of glioma cells. To further study RTVP-1 effects we performed a pull-down assay using His-tagged RTVP-1 followed by mass spectrometry and found that RTVP-1 was associated with the actin polymerization regulator, N-WASP. This association was further validated by co-immunoprecipitation and FRET analysis. We found that RTVP-1 increased cell spreading, migration and invasion and these effects were at least partly mediated by N-WASP. Another protein which was found by the pull-down assay to interact with RTVP-1 is hnRNPK. This protein has been recently reported to associate with and to inhibit the effect of N-WASP on cell spreading. hnRNPK decreased cell migration, spreading and invasion in glioma cells. Using co-immunoprecipitation we validated the interactions of hnRNPK with N-WASP and RTVP-1 in glioma cells. In addition, we found that overexpression of RTVP-1 decreased the association of N-WASP and hnRNPK. In summary, we report that RTVP-1 regulates glioma cell spreading, migration and invasion and that these effects are mediated via interaction with N-WASP and by interfering with the inhibitory effect of hnRNPK on the function of this protein.
Medical Subject Headings
Brain Neoplasms; Cell Line, Tumor; Cell Movement; Cell Shape; Fluorescence Resonance Energy Transfer; Gene Expression Regulation, Neoplastic; Glioblastoma; Heterogeneous-Nuclear Ribonucleoprotein K; Humans; Immunoprecipitation; Mass Spectrometry; Neoplasm Invasiveness; Neoplasm Proteins; Neoplastic Stem Cells; Nerve Tissue Proteins; Protein Binding; Proteomics; RNA Interference; Ribonucleoproteins; Signal Transduction; Transfection; Tumor Cells, Cultured; Wiskott-Aldrich Syndrome Protein, Neuronal