Figure 1 from Combining Brigatinib with mTOR Inhibition to Effectively Treat NF2-SWN–Associated and Sporadic NF2-Deficient Meningiomas

Morphologic and immunologic characterization of the AG-NF2-Men tumor and immortalized cell line. A and B, Hematoxylin and eosin (H&E) staining of tumor sections of the AG-NF2-Men meningioma from an NF2-SWN patient showed a typical whorling architecture and psammoma bodies. C, IHC analysis of AG-NF2-Men tumor sections revealed membrane and cytoplasmic expression of EMA, commonly found in meningioma cells. D, Immunofluorescence staining detected VIM expression (green) in the cytoplasm of AG-NF2-Men cells. DAPI stained the nuclei in blue. E and F, Phase-contrast micrographs of the AG-NF2-Men primary culture (E) and immortalized cells (F). Like the primary culture, immortalized AG-NF2-Men cells exhibit a spider web–like growth pattern. G, Western blot analysis confirmed that like the Ben-Men-1 cell line established from a sporadic grade 1 meningioma, AG-NF2-Men cells did not express detectable merlin protein, whereas normal meningeal cells (MC) and HeLa cervical carcinoma cells readily expressed merlin. Also, the merlin protein was not detected in primary cultures of four meningiomas from different patients (Men-1 to Men-4). In addition, DSP, a desmosomal component often expressed by meningioma cells, was detected in AG-NF2-Men cells, Ben-Men-1 cells, MCs, and primary meningioma cells. kD, kilodalton of molecular weight.