Enhancing Therapeutic Approaches in Glioblastoma with Prooxidant Treatments and Synergistic Combinations: <em>In Vitro</em> Experience of Doxorubicin and Photodynamic Therapy

Abstract

Glioblastoma (GBM) is an aggressive brain cancer characterized by significant molecular and cellular heterogeneity, complicating treatment efforts. Current standard therapies, including surgical resection, radiation, and temozolomide (TMZ) chemotherapy, often fail to achieve long-term remission due to tumor recurrence and resistance. A pro-oxidant environment is in-volved in glioma progression, with oxidative stress contributing to the genetic instability that leads to gliomagenesis. However, the generation of reactive oxygen species (ROS) results in the dysregulation of antioxidant defenses in GBM cells, creating a vulnerability that can be thera-peutically exploited. Evaluating pro-oxidant therapies in brain tumors is crucial due to their po-tential to selectively target and eradicate cancer cells by exploiting the elevated oxidative stress levels inherent in these malignant cells, thereby offering a novel and effective strategy for overcoming resistance to conventional therapies. This study investigates the therapeutic potential of doxorubicin (DOX) and photodynamic therapy (PDT) with Me-ALA, focusing on their effects on redox homeostasis. Basal ROS levels and antioxidant gene expression (NFE2L2, CAT, GSR) were quantitatively assessed across GBM cell lines, revealing significant variability probably linked to genetic differences. DOX and PDT treatments, both individually and in combination, were ana-lyzed for their efficacy in inducing oxidative stress and cytotoxicity. An in silico analysis further explored the relationship between gene mutations and oxidative stress in GBM patients, providing insights into the molecular mechanisms underlying treatment responses. Our findings suggest that pro-oxidant therapies, such as DOX and PDT in combination, could selectively target GBM cells, highlighting a promising avenue for improving therapeutic outcomes in GBM.