Low-Dose DMC Significantly Enhances the Effect of TMZ on Glioma Cells by Targeting Multiple Signaling Pathways Both In Vivo and In Vitro.

Temozolomide (TMZ) is widely used for treating glioblastoma (GBM), which can effectively inhibit the GBM growth for some months; however, it still cannot prevent the invariable recurrence of GBM. Improving the chemotherapeutic sensitization becomes an urgent agenda. In this study, we found low-dose demethoxycurcumin (DMC) could enhance the sensitivity of TMZ on glioma cells, and high-dose DMC has more significant effects on GBM cells compared with TMZ treatment alone both in vitro and in vivo. And co-administration of DMC and TMZ resulted in a significant increase in GBM apoptosis and a marked inhibition of cell growth pathogenesis of GBM. Mechanistically, DMC and TMZ synergistically increase intracellular level of reactive oxygen species (ROS) production, activate caspase-3-dependent apoptotic pathway, and inactivate of JAK/STAT3 signaling pathway in GBMs, which account for the cell apoptosis and proliferation inhibition. Together, these data implicate that low-dose DMC combined with TMZ represents an effective therapy regimen against GBMs by targeting multiple signaling pathways.