Experimental and clinical studies on radiation and curcumin in human glioma

Abstract

Purpose There is progressing evidence for the anti-cancer potential of the natural compound and dietary spice curcumin. Curcumin has been ascribed to be cytotoxic for various tumour cell types, to inhibit cell proliferation and to interfere with the cellular oxidant status. The compound has been notified as a therapeutic agent with radiosensitizing potential in brain tumour therapy. We considered the rationale to combine curcumin with radiation in the treatment of human glioblastoma multiforme (GBM). Method Determination of clonogenic cell survival following exposure of U251 human glioma cells to single dose (1–6 Gy) and fractionated irradiation (5 daily fractions of 2 Gy) without and with curcumin. Additional literature search focused on the interaction between curcumin and radiotherapy in experimental and clinical studies on human glioma. Results No interaction was found on the survival of U251 human glioma cells after irradiation in combination with curcumin at clinically achievable concentrations. Experimental in vitro and in vivo data together with clinical bioavailability data from the literature do not give evidence for a radiosensitizing effect of curcumin. Reported GBM intratumoural curcumin concentrations are too low to either exert an own cytotoxic effect or to synergistically interact with radiation. Novel approaches are being explored to increase the bioavailability of curcumin and to facilitate transport over the blood–brain barrier, aimed to reach therapeutic curcumin levels at the tumour site. Conclusion There is neither a biological nor clinical rationale for using curcumin as radiosensitizer in the therapy of GBM patients.

Radiotherapy of High-Grade Gliomas: First Half of 2021 Update with Special Reference to Radiosensitization Studies

“…Curcumin has been proposed as a therapeutic agent with radiosensitizing potential in brain tumor therapy [81]. No interaction was found on the survival of U251 human glioma cells after irradiation in combination with curcumin at clinically achievable concentrations.…”

“…Reported HGG intratumoral curcumin concentrations were too low to either exert their own cytotoxic effect or to synergistically interact with IR. At present, there is neither a biological nor clinical rationale for using curcumin as a radiosensitizer in the therapy of HGG patients [81].…”

Circular RNA: A novel type of biomarker for glioma (Review)

“…circRNAs regulate the tumorigenicity of glioma cells. Numerous genetic studies on glioma have determined that gene mutations can promote the tumorigenicity of glioma cells (2,78,79). In general, glioma-related genes can be separated into two classes: Oncogenes and tumor suppressor genes.…”

“…Glioma is the most prevalent type of primary tumor of the central nervous system and accounts for >75% of malignant brain tumors (1,2). Histologically, glial-derived tumors, or gliomas, share characteristics of normal glial cells, glial or neural precursors and stem cells, and are generally named based on these similarities (3)(4)(5).…”

“…Recent advances in molecular understanding have provided new insights and novel molecular subclassification of gliomas. These molecular subtypes include subependymal giant cell astrocytoma, pilocytic astrocytoma, epithelioid glioblastoma, oligodendroglioma and mesenchymal glioblastoma ( 2 , 3 ). Early detection of gliomas may be difficult due to their deep location in the brain and lack of obvious clinical symptoms at the early stages ( 4 , 6 ).…”