الفهرس | Only 14 pages are availabe for public view |
Abstract Background: High-grade gliomas (HGGs) are aggressive brain tumors with high vascularity. Furthermore, because the blood brain barrier (BBB) protects the tumor bulk, at least partially, the endothelial cells of brain tumors are much more easily exposed than tumor substances. As a result, in brain tumors, it appears that targeting the endothelium is more promising in terms of imaging and therapeutic potential. Prostatic specific membrane antigen (PSMA) is expressed specifically by the endothelium of the neovasculature in many solid tumors, implying a role for PSMA in tumor angiogenesis. Aim of the work: Evaluation of the immunohistochemical (IHC) expression of PSMA in neovasculature (identified by CD 31) of high-grade gliomas and its relationship to other clinical and pathological features in order to determine its potential prognostic value. Methods: 69 cases of high-grade gliomas were obtained by collecting archived paraffin blocks, from the Pathology department, of Kasr Al-Ainy, Faculty of Medicine, Cairo University, during the period from January 2015 till January 2020 and private labs to evaluate the IHC expression of PSMA in neovasculature. PSMA expression was assessed using the composite PSMA staining score. A score (0) was considered negative while scores 1-7 were considered positive (1–4, 5–6 or 7; weak, moderate or strong respectively). Results: PSMA expression was detected in endothelial cells of tumor microvessels (TMV) as well as in tumor parenchymal cells in ”(53/69) (76.8%) and 39/69 (56.5%)” of cases respectively, while it was not detected in normal brain tissue found occasionally admixed with our cases. There was no statistically significant relationship between PSMA expression in TMV and tumor cells and any of [tumor site, histological grade]. Yet, there was a statistically significant relationship between PSMA expression in TMV or in tumor cells and various glioma subtypes. Conclusion: Evidently, PSMA was expressed in a significant proportion of TMV and tumor cells of HGGs, Thus, PSMA may represent a promising target for theranostic approaches, in conjunction with current standard care, to improve diagnostic and treatment efficacy through PSMA-inhibiting drugs or PSMA-mediated administration of chemotherapeutics or radiation agents. |