Related to Testes-Specific, Vespid, and Pathogenesis Protein-1 (RTVP-1) Is Overexpressed in Gliomas and Regulates the Growth, Survival, and Invasion of Glioma Cells

Authors:
Rosenzweig T, Ziv-Av A, Xiang C, Lu W, Cazacu S, Taler D, Miller CG, Reich R, Shoshan Y, Anikster Y, Kazimirsky G, Sarid R, Brodie C
In:
Source: Cancer Res
Publication Date: (2006)
Issue: 66(8): 4139-48
Research Area:
Cancer Research/Cell Biology
Neurobiology
Cells used in publication:
U87
Species: human
Tissue Origin: brain
A172
Species: human
Tissue Origin: brain
Abstract
In this study, we examined the expression and functions of related to testes-specific, vespid, and pathogenesis protein 1 (RTVP-1) in glioma cells. RTVP-1 was expressed in high levels in glioblastomas, whereas its expression in low-grade astrocytomas and normal brains was very low. Transfection of glioma cells with small interfering RNAs targeting RTVP-1 decreased cell proliferation in all the cell lines examined and induced cell apoptosis in some of them. Overexpression of RTVP-1 increased astrocyte and glioma cell proliferation and the anchorage-independent growth of the cells. In addition, overexpression of RTVP-1 rendered glioma cells more resistant to the apoptotic effect of tumor necrosis factor-related apoptosis-inducing ligand and serum deprivation. To delineate the molecular mechanisms involved in the survival effects of RTVP-1, we examined the expression and phosphorylation of various apoptosis-related proteins. We found that overexpression of RTVP-1 decreased the phosphorylation of c-Jun-NH(2)-kinase and increased the expression of Bcl(2) and that the protective effect of RTVP-1 was partially mediated by Bcl(2). Finally, we found that RTVP-1 regulated the invasion of glioma cells as was evident by their enhanced migration through Matrigel and by their increased invasion in a spheroid confrontation assay. The increased invasive potential of the RTVP-1 overexpressors was also shown by the increased activity of matrix metalloproteinase 2 in these cells. Our results suggest that the expression of RTVP-1 is correlated with the degree of malignancy of astrocytic tumors and that RTVP-1 is involved in the regulation of the growth, survival, and invasion of glioma cells. Collectively, these findings suggest that RTVP-1 is a potential therapeutic target in gliomas.