Establishment of a novel benign meningioma cell line spontaneously immortalized under hypoxic conditions

Meningiomas are the most frequent brain tumors, typically benign and curable by surgery. However, some patients experience repeated recurrences from residual tumors. To address such cases, the development of novel therapeutic options is crucial. For this purpose, the availability of cell lines that possess the characteristics of benign meningiomas is essential. Here, we established a benign meningioma cell line under 3% O₂ hypoxic conditions without the induction of immortalization genes. This cell line, named TKB-MEN2, has been stably grown for over two years with more than 20 passages. There were no hotspot telomerase reverse transcriptase (TERT) promoter mutations or cyclin-dependent kinase inhibitor 2A/2B (CDKN2A/2B) homozygous deletions, which are genetic features typical of malignant meningiomas. Cultured under hypoxic conditions, this cell line showed fewer characteristics of cellular senescence, such as morphological changes, IL-6 secretion, and lower senescence-associated b-galactosidase activity, compared to the same cell line cultured under 20% O₂ conditions. This immortalized non-transgenic cell line appears to reflect the characteristics of a genuine benign meningioma, potentially allowing the identification of new therapeutic targets and the development of novel therapies for benign meningiomas.