Identification of epithelial membrane protein 2 (EMP2) as a molecular marker and correlate for angiogenesis in meningioma

Purpose Although intracranial meningiomas are the most common primary brain tumor in adults, treatment options are few and have traditionally been limited to surgical resection and radiotherapy. Additional targeted therapies and biomarkers are needed, especially as complete surgical resection is frequently not feasible in many patients. Methods Non-pathologic brain tissue from 3 patients undergoing routine autopsies and tumor specimens from 16 patients requiring surgical resection for meningioma were collected. EMP2 protein expression was evaluated by immunohistochemistry and western blot analysis. EMP2 mRNA expression was also investigated using surgical specimens and validated by analysis of several independent NCBI GEO databases. Results EMP2 mRNA expression levels were found to be higher in meningioma relative to non-pathologic meninges ( P = 0.0013 ) and brain ( P = 0.0011 ). Concordantly, strong EMP2 protein expression was demonstrated in 100% of meningioma specimens from all 16 patients, with no observable protein expression in normal brain tissue samples from 3 subjects ( P