Amlexanox Enhances Temozolomide-Induced Antitumor Effects in Human Glioblastoma Cells by Inhibiting IKBKE and the Akt-mTOR Signaling Pathway

Temozolomide (TMZ), as the first-line chemotherapeutic agent for the treatment of glioblastoma multiforme (GBM), often fails to improve the prognosis of GBM patients due to the quick development of resistance. The need for more effective management of GBM is urgent. The aim of this study is to evaluate the efficacy of combined therapy with TMZ and amlexanox, a selective inhibitor of IKBKE, for GBM. We found that the combined treatment resulted in significant induction of cellular apoptosis and the inhibition of cell viability, migration, and invasion in primary glioma cells and in the human glioma cell line, U87 MG. As expected, TMZ enhanced the expression of p-AMPK and amlexanox led to the reduction of IKBKE, with no impact on p-AMPK. Furthermore, we demonstrated that compared to other groups treated with each component alone, TMZ combined with amlexanox effectively reversed the TMZ-induced activation of Akt and inhibited the phosphorylation of mTOR. In addition, the combination treatment also clearly reduced in vivo tumor volume and prolonged median survival time in the xenograft mouse model. These results suggest that amlexanox sensitized the primary glioma cells and U87 MG cells to TMZ at least partially through the suppression of IKBKE activation and the attenuation of TMZ-induced Akt activation. Overall, combined treatment with TMZ and amlexanox may provide a promising possibility for improving the prognosis of glioblastoma patients in clinical practice.