Figure 1.

WNT6 is overexpressed at the mRNA and protein levels in GBM. (A) Expression levels of WNT6 in 27 lower-grade gliomas (LGG; grey dots), 572 glioblastomas (GBM, WHO grade IV; black and colored dots) and 10 unmatched normal brains (black unfilled dots) from TCGA. GBM molecular subtypes are represented as colors (red = classical; blue = proneural; green = neural; yellow = mesenchymal). WNT6 is overexpressed (TCGA data level 3 values ≥ 0.41; above red dashed line) in 16% (n = 89) of GBM samples. (B) WNT6 protein expression in WHO grades I-IV glioma samples from Hospital Santo António cohort assessed by IHC (n = 63; p = 0.037; chi-squared test). Representative images are shown for a WNT6-negative GBM (a), high WNT6 expression in GBM (b) and WHO grade III anaplastic oligoastrocytoma (c), and a WHO grade II diffuse oligodendroglioma with intermediate levels of WNT6 expression (d). WNT6 staining was mostly cytoplasmic in glioma cells (closed arrowheads) and not present in lymphocytes (e; arrow), being almost exclusively negative for endothelial cells (b-d and f; open arrowheads). Bottom graph summarizes IHC data for the whole dataset. LGG: lower-grade glioma; TCGA: The Cancer Genome Atlas; WHO: World Health Organization.