Interferon-α/β enhances temozolomide activity against MGMT-positive glioma stem-like cells

Abstract

Glioma is one of the most common primary tumors of the central nervous system in adults. Glioblastoma (GBM) is the most lethal type of glioma, whose 5-year survival is 9.8% at best. Glioma stem-like cells (GSCs) play an important role in recurrence and treatment resistance. MGMT is a DNA repair protein that removes DNA adducts and therefore attenuates treatment efficiency. It has been reported that interferon-α/β (IFN-α/β) downregulates the level of MGMT and sensitizes glioma cells to temozolomide. In the present study, we assessed whether IFN-α/β is able to sensitize GSCs to temozolomide by modulating MGMT expression. Upon the treatment of IFN-α/β, the efficacy of temozolomide against MGMT-positive GSCs was markedly enhanced by combination treatment with IFN-α/β when compared with the temozolomide single agent group, and MGMT expression was markedly decreased at the same time. Further mechanistic study showed that IFN-α/β suppressed the NF-κB activity, which further mediated the sensitization of MGMT-positive GSCs to temozolomide. Our data therefore demonstrated that the application of IFN-α/β is a promising agent with which to enhance temozolomide efficiency and reduce drug resistance, and our findings shed light on improving clinical outcomes and prolonging the survival of patients with malignant gliomas.