Temozolomide increases MHC-I expression via NF-κB signaling in glioma stem cells

Gliomas are the most common and primary tumors of the central nervous system in adults. Temozolomide (TMZ) is the main drug used to treat glioma; however, prognosis remains poor for most patients. Glioma stem cells (GSCs) are thought to enable glioma initiation and evasion from immune surveillance; their immunogenicity can be determined by expression of major histocompatibility complex (MHC)-I. The present study investigated the effect of TMZ on MHC-I expression in GSCs. Glioma spheres were cultured in serum-free medium containing epidermal growth factor, basic fibroblast growth factor, and B27; MHC-I expression was detected by immunocytochemistry, quantitative real-time PCR, and flow cytometry. Nuclear factor (NF)-kB expression in glioma stem cells was detected by Western blot. TMZ enhanced MHC-I expression in GSCs, and NF-kB was activated. TMZ treatment increased MHC-I expression via modulation of NF-kB signaling in GSCs. In addition to being a chemotherapeutic agent, TMZ may also serve as an immunomodulatory agent in the treatment of glioma patients.