Radiosensitization and Radioprotection by Curcumin in Glioblastoma and Other Cancers

Abstract

Radiation therapy plays an important role in almost every cancer treatment. However, radiation toxicity to normal tissues, mainly due to the generation of reactive free radicals, has limited the efficacy of radiotherapy in clinical practice. Curcumin has been reported to possess significant antitumor properties. Although curcumin can sensitize cancer cells to irradiation, healthy cells are much less sensitive to this effect, and thus, curcumin is thought to be a potent, yet safe anti-cancer agent. In this review, a summary of the role of curcumin as both a radiosensitizer and radioprotector has been presented, based on the most recent data from the experimental and clinical evaluation of curcumin in different cancer cell lines, animal models, and human patients.

Keywords: cancer; curcumin; radiation therapy; radiosensitizer.

Figure 1

Chemical structure of curcumin.

Figure 2

Molecular targets of curcumin contribute to radiosensitization in different cancers. Abbreviations: CDK: cyclin-dependent kinase; Akt: protein kinase B; ILK: integrin-linked kinase; FAK: focal adhesion kinase; DNMT: DNA methyltransferase; EGFR: endothelial growth factor receptor; EMT: epithelial–mesenchymal transition; ROS: reactive oxygen species; TR: trypanothione reductase; HIF-1a: hypoxia-inducible factor 1-alpha; HSP90: heat shock protein 90; NF-κB: nuclear factor-κB; bax: bcl-2-like protein 4, TNF-a: tumor necrosis factor-a; MDR1: multidrug resistance protein 1; XRCC5: X-ray repair cross-complementing 5; LIG4: ligase 4; PNPK: polynucleotide kinase/phosphatase; Gli1: glioma-associated oncogene homologue 1; SMO: smoothened.