The mitochondrial apoptosis profile in meningiomas and gliomas: Comparing the effects of patient sex, tumor histology, and grade.

Abstract

e14063 Background: Gliomas and meningiomas are the most common malignant (primary) and benign brain tumors, respectively. Mitochondrial dysfunction plays an important role in the pathogenesis of neoplasms across all locations. This study aimed to investigate the features of key apoptosis marker levels in the mitochondria (Mx) of brain tumor cells. Methods: The study included 18 patients with supratentorial brain tumors: gliomas (n=12, comprising LGG G2 (17%, n=3) and HGG G3 (50%, n=9)) and meningiomas (n=6). All patients underwent cytoreductive tumor resection. Progression within the first year was observed in all glioblastoma patients and one patient with G3 astrocytoma. The mean patient age was 52.91 ± 12.03 years, with 56% male and 44% female. Mitochondria were isolated using standard differential centrifugation with an Avanti J-E high-speed refrigerated centrifuge (Beckman Coulter, USA). The mitochondrial fractions were analyzed by enzyme-linked immunosorbent assay (ELISA) for cytochrome C (Bioscience, Austria), AIF and Bcl-2 (Cloud-Clone Corp., China), and calcium (Ca²⁺) (Abris, Russia) content. Statistical analysis followed standard guidelines for medical research. Results: AIF content in glioma Mx did not differ from that in meningioma Mx for patients of either sex. Only in males was Ca²⁺ content in meningioma Mx 4.3-fold lower than in females with meningiomas (p=0.0001) and males with gliomas (p=0.0011). The Bcl-2 level in glioma Mx was lower than in meningioma Mx by 5.6-fold in males (p=0.00001) and 5.8-fold in females (p=0.00001). Bcl-2 levels in meningioma Mx did not differ between sexes, whereas Bcl-2 content in glioma Mx was 1.5-fold lower in males than in females (p=0.025). The most notable findings were related to cytochrome C content. In meningioma Mx, the lowest values were characteristic of females, being 2.0-fold lower (p=0.0016) than in males with meningiomas. Conversely, in glioma Mx, the lowest values were in males, being 1.8-fold lower (p=0.0093) than in females with gliomas. Consequently, cytochrome C content in glioma Mx was 1.7-fold lower in males (p=0.0102) and 2.2-fold higher in females (p=0.0025) compared to patients of the corresponding sex with meningiomas. Conclusions: The mitochondrial apoptosis profile in brain tumors is not consistently linked to histological type, tumor grade, or malignancy. Patient sex appears to be a more significant factor, particularly regarding cytochrome C content.