New Anti-Cancer Impact of Cerium Oxide, Lithium, and Sn-38 Synergy via DNA Methylation-Mediated Reduction of MMP-2 and Modulation of the PI3K/Akt/mTOR Pathway

<b>Background/Objectives:</b> Glioblastoma, the most common primary tumor of the central nervous system, is characterized by high malignancy and poor prognosis. One of the main challenges in neurological disorders is to develop an effective treatment modality that can cross the blood-brain barrier. Nanoparticles are revolutionary for neurodegenerative diseases due to their targeted delivery and ability to overcome biological barriers. Cerium oxide (Ce₂O₃) nanoparticles are suitable for use as drug delivery systems. <b>Methods:</b> In our study, we investigated the anticancer mechanism using SN-38, lithium, and Ce₂O₃, a powerful agent used in GBM treatment. We evaluated their anticancer activities separately and in combination with U373 cell lines. GBM cell line U373 cells were cultured. Then, all groups except the control group were treated with different doses of SN-38 and lithium combination therapy with SN-38, lithium, and Ce₂O₃ combination therapy. The results were evaluated using MTT and ELISA tests. <b>Results:</b> When the results were examined, anticancer activity was detected at PTEN, AKT, mTOR, and BAX/Bcl-2 levels in the SN-38 + NPs 25 µg/mL + Lithium 50 µg/mL and SN-38 + NPs 50 µg/mL + Lithium 50 µg/mL dose groups. In addition, findings that inflammation markers were correlated with the apoptosis mechanism were obtained. <b>Conclusion:</b> This study is the first to report that combining lithium with SN-38 and NPs increased oxidative stress more than lithium with SN-38, leading glioblastoma cells to apoptosis and its potential anticancer activity. These results provide a basis for further investigation of its clinical application in cancer treatment.