Qi Zhang, Chao Hu, Yanjiao He, Guilin Li
This paper aims to investigate the role and mechanism of autophagy in meningioma. A total of 182 meningiomas which diagnosed in the ultrastructural pathology department of Beijing Neurosurgical Institute, Beijing Tiantan Hospital from 1993 to 2021. Light microscope, electron microscope, western blotting and immunohistochemical staining were used. 182 meningiomas, 104 males and 78 females. There were 174 WHO grade 1 benign meningiomas, including 62 meningothelial types, 39 fibrous type, 58 transitional types, 15 angiomatous types, 6 WHO grade 2 cases, including 4 clear cell types and 2 atypical types, 2 WHO grade 3 anaplastic types. Transmission electron microscopy (TEM) showed that the incidence of autophagosomes as a high expression in 27 cases, most of which were meningothelial meningiomas. Immunohistochemical markers EMA, PR, Vimentin, SSTR-2, Ki67, and CD34 were positively expressed in most of the tumors, GFAP, S-100, desmin, C-erbB-2 expression were negative. Western blotting was used to detect the up-regulated proteins of LC3, Beclin1, and down-regulated proteins of Bax, Caspase3, mTOR, PI3K, Akt, S6 and 4EBP1in meningothelial meningiomas compared with the none –meningothelial control group.Autophagy is induced by down-regulating PI3K/Akt/mTOR signaling pathway molecules in meningothelial meningiomas, which can inhibit tumor apoptosis and promote tumorigenesis.