Constitutive activation of signal transducer and activator of transcription 3 regulates expression of vascular endothelial growth factor in human meningioma differentiation

PURPOSE: Janus tyrosine kinases (JAKs) and signal transducer and activator of transcription factors (STATs), especially STAT3, are constitutively activated in human cancers. The function of STAT3 in the pathogenesis of meningioma remains unknown. In this study, we investigated the role of JAK1/STAT3 regulating vascular endothelial growth factor (VEGF) expression in the occurrence and progression of human meningioma. METHODS: We detected the expression of JAK1, p-JAK1, STAT3, p-STAT3, and VEGF in human meningioma and normal dura tissues by RT–PCR, Western blot analysis, and immunohistochemistry. RESULTS: JAK1, p-JAK1, STAT3, p-STAT3, and VEGF showed high expression in grade I and grade II meningioma. The level of STAT3 activation was associated with VEGF expression; all meningioma tumors that expressed p-STAT3 also expressed VEGF. Both frequency of positivity and expression were enhanced with increasing tumor grade; high frequencies and levels were found in grade II tumors, with no expression detected in normal dura tissues (P < 0.05). CONCLUSIONS: VEGF is directly regulated by constitutive STAT3 activity and associated with meningioma differentiation. STAT3 has an important role in the occurrence and development of human meningioma by regulating VEGF expression.