C-Myc mRNA and protein levels were not grade-related, but validated subdivision of the 36 benign meningiomas into two groups, Groups IA and IB, based on histological and clinical features (Ki-67-proliferative index, absence or presence of mitoses, rate of recurrence and incidence of perilesional edema).
Further validation methods for gene expression included quantitative PCR (qPCR), western blot and immunohistochemistry analysis, and these methods confirmed that RIZ1 is significantly downregulated in malignant meningioma tissues, as compared with benign meningiomas.
We have studied the role of micro-RNA 145 (miR-145) in meningiomas and detected significantly reduced miR-145 expression in atypical and anaplastic tumors as compared with benign meningiomas.
Together with histological grade, increased co-expression of MIF and MMP9 in tumor might be a valuable predictor for recurrence, especially for benign meningiomas.
Additionally, we found significant upregulation of CCNB1 and MKI67 in recurrent tumors in comparison with primary tumors of benign meningiomas (P<0.05).
ELISA analysis showed that patients with benign meningiomas and ovarian cancers had the highest serum levels of EGFL6 (mean concentration: 672 pg/ml for benign meningiomas, and 616 pg/ml for ovarian cancers).
We examined by immunohistochemistry the expression of HGF/SF and its cMET receptor in a group of patients with benign meningioma with or without recurrence (n = 17 and n = 25, respectively), after a minimal follow-up of least 6 years.
Together with histological grade, increased co-expression of MIF and MMP9 in tumor might be a valuable predictor for recurrence, especially for benign meningiomas.
We performed direct sodium bisulfite sequencing in a series of 50 meningiomas, including 27 benign meningiomas [World Health Organization (WHO) grade I], 11 atypical meningiomas (WHO grade II) and 12 anaplastic meningiomas (WHO grade III), and found hypermethylation of TIMP3 in 67% of anaplastic meningiomas, but only 22% of atypical and 17% of benign meningiomas.
The immunoprofile was similar to normal cap cells with one exception; whereas normal cells were uniformly negative forPR, nuclear positivity was seen in 64% of hyperplasias, a frequency similar to that of benign meningiomas.
The reported patient, in addition to glioma, had suffered from benign meningioma in the past but did not show any clinical signs of Cowden disease or other hereditary diseases typically associated with PTEN germline mutations.