Figure 1

Abundant expression of WNK1/OSR1/NKCC1 in primary glioma cells and GBM tissues. A. Representative immunoblots for expression of either phosphorylated (p-) or total (t-) NKCC1, WNK1, OSR1 and SPAK in human neural stem cell (NSC), human astrocyte (HA), primary GC#99, GC#22 and U87. B. Summary data of immunoblotting. Upper and middle panels, expression of each protein was first normalized by α-tubulin and relative expression level in each cell type was then normalized to NSC. Lower panel, expression of each phosphorylated protein was first normalized by its total protein and relative expression level in each cell type was then normalized to NSC. Data are mean ± SEM. n = 3, *p < 0.05 vs. NSC. C. Representative immunofluorescent staining of p-NKCC1, t-NKCC1 in xenograft brain tissues of SCID mouse derived from glioma stem cell (GSC#22). Arrow, representative cells with positive staining of protein of interest. Insets: images with higher magnification. D. Representative immunostaining of p-OSR1, t-OSR1 in xenograft brain tissues of SCID mouse derived from glioma stem cell (GSC#22). White box in whole-brain images indicates the corresponding location of acquisition for high magnification photomicrographs. Arrow, representative cells with positive staining of protein of interest. Insets: negative controls with primary antibodies omitted. E. Representative images of p-OSR1 immunohistochemistry with different p-OSR1 immunohistochemistry staining intensity in a tissue microarray (TMA) of GBM. Arrow, representative cells with positive staining of protein of interest. F. Summary data of percentage of patients observed with different p-OSR1 expression scores with either normal or GBM group.