Molecular Insights into Photodynamic Therapy of Glioma

Abstract

Cancers, a large and heterogeneous group of malignancies, are becoming an increasingly important cause of premature mortality worldwide. 2% of these are primary CNS tumors, of which 24% are gliomas. These tumors are diverse, but what they have in common is one of the most unfavorable prognoses among all cancers. A patient's future varies depending on the grade of the diagnosed glioma. To date, however, no standard treatment for grade IV has been established. All glioblastomas eventually undergo progression or recurrence. The current standard of treatment, which includes surgical intervention, radiation therapy and chemotherapy, is therefore far from sufficient. Work is constantly underway to discover a new, effective form of glioma therapy. Photodynamic therapy (PDT) may be one of them. It involves the local or systemic application of a photosensitive compound - a photosensitizer (PS), which accumulates in the affected tissues. Photosensitizer molecules absorb light of the appropriate wavelength, initiating activation processes leading to the formation of reactive oxygen species and selective destruction of inappropriate cells. Currently, this method has been approved for the treatment of several cancers. Research focusing on the effective use of PDT in glioma therapy is already underway, with promising results. In our work, we present molecular insights into PDT of glioma. Based on the available literature, we analyze and systematize the impact of various molecules, proteins, transporters and transmitters on the efficacy of PDT and the effect of PDT on their expression. In addition, we highlight gaps in current knowledge and point out directions for future research that may contribute to the efficacy of PDT glioma.