Among the GBM cases it was noted that the IDH1 immunopositive tumors (R132H mutant protein; n=17) had a low MnSOD expression as opposed to IDH1 immunonegative tumors (n=106), which had high expression of MnSOD (p=0.0307).
Three GBM-O samples had IDH1 (p.R132H) mutations; two of these also demonstrated 1p/19q co-deletion and had a proneural transcriptional profile, a molecular signature characteristic of oligodendroglioma.
A total of 15.3% of enrolled GBMs demonstrated loss of ATRX expression (ATRX-), 10.4% expressed an aberrant IDH1 R132H protein (IDH1+), and 48.4% exhibited p53 overexpression (p53+).
Tumors with NF1/Ch17 loss were predominantly adult GBM (4/5); lacked EGFR amplification (0/4), strong p53 immunolabeling (1/5), or IDH1 (R132H) protein expression (0/5); but expressed the mesenchymal marker podoplanin in 4/5.
Using antibody against p53 and IDH1 R132H, the authors immunohistochemically analyzed GBM tissue from patients who had undergone surgery at the University of Miyazaki Hospital during August 2005-December 2011.
One index case with glioblastoma multiforme (GBM) diagnosed at age 54 and had a family history comprised of a paternal aunt with GBM at age 55, carried the p53 R158H mutation, which is predicted to be functional and has previously been implicated as a cause of Li-Fraumeni syndrome.