Presence of an early lineage stem cell phenotype in meningioma-initiating cells

Meningiomas are a common form of adult brain tumors. Although most meningiomas are benign tumors that are associated with favorable outcomes, a small group of patients develop more aggressive manifestations which currently are more difficult to treat. It has increasingly been recognized that tumor stem-like cells play critical roles in tumor recurrence, angiogenesis, and invasion in malignant brain tumors. Several recent studies identified the stem-like features of sphere-forming cells in human meningiomas. These meningioma sphere cells expressed various progenitor cell biomarkers and can undergo differentiation if appropriate stimuli are applied. Moreover, these meningioma stem-like cells are more resistant to irradiation treatment, and tumorigenic in in vivo xenograft models. These new findings could lead to a better understanding of the development and etiology of meningioma formation and suggest that meningioma stem-like cells may serve as a novel target in therapeutically resistant meningiomas.