Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
Department of Medical Physics, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
J Cancer Res Ther. 2023 Apr;19(Supplement):S67-S73. doi: 10.4103/jcrt.JCRT_1087_21.
The purpose of the study was to investigate the radiosensitization effect of radiofrequency (RF) hyperthermia in combination with PEGylated gold nanoparticles (PEG-GNPs) on MCF-7 breast cancer cells under electron beam radiotherapy (EBRT) based on the clonogenic assay.
The cell death of MCF-7 breast cancer cells treated with 13.56 MHz capacitive RF hyperthermia (power: 150W) for 2, 5, 10, and 15 min combined with 6 MeV EBRT, with a dose of 2 Gy, was evaluated in the presence of 20 nm PEG-GNPs with a low nontoxic concentration (20 mg/l). All the treatment groups were incubated for 14 days. Thereafter, survival fractions and viability of the cells were calculated and analyzed against the control group.
The presence of PEG-GNPs inside the MCF-7 cancer cells during electron irradiation decreased cell survival significantly (16.7%) compared to irradiated cells without GNPs. Applying hyperthermia before electron irradiation with a capacitive RF system decreased cell survival by about 53.7%, while hyperthermia without irradiation did not show any significant effect on cell survival. Combining the hyperthermia with the presence of PEG-GNPs in the cells decreased the cell survival by about 67% at the electron irradiation, showing their additive radiosensitization effect.
Low nontoxic concentration of 20 nm PEG-GNPs increases the radiosensitization effect of combining 6 MeV EBRT and RF hyperthermia on MCF-7 cancer cells. Combining hyperthermia with PEG-GNPs in electron radiotherapy could be an appropriate method for enhancing radiotherapy effectiveness on cancerous cells which can be studied on different cells and electron energies in future research.
本研究旨在通过集总式射频（RF）热疗联合聚乙二醇金纳米粒子（PEG-GNPs），基于克隆形成实验，探究其对 MCF-7 乳腺癌细胞在电子束放射治疗（EBRT）下的放射增敏效应。
采用 13.56MHz 电容式 RF 热疗（功率：150W），分别对 MCF-7 乳腺癌细胞作用 2、5、10 和 15min，联合 6 MeV EBRT（剂量为 2Gy），同时加入低毒性浓度（20mg/L）的 20nm PEG-GNPs，评估 MCF-7 乳腺癌细胞的死亡情况。所有处理组孵育 14 天。之后，计算并分析各处理组的存活分数和细胞活力相对于对照组的情况。
电子照射时，PEG-GNPs 存在于 MCF-7 癌细胞内，与无 GNPs 照射的细胞相比，细胞存活率明显降低（16.7%）。采用集总式 RF 系统对电子照射前进行热疗，细胞存活率降低约 53.7%，而无照射的热疗对细胞存活率没有显著影响。在细胞内存在 PEG-GNPs 的情况下，将热疗与电子照射相结合，细胞存活率降低约 67%，表现出其相加的放射增敏效应。
低毒性浓度的 20nm PEG-GNPs 增加了 6 MeV EBRT 联合 RF 热疗对 MCF-7 癌细胞的放射增敏效应。在电子放射治疗中，将热疗与 PEG-GNPs 联合使用可能是增强对癌细胞放射治疗效果的一种合适方法，这可以在未来的研究中在不同细胞和电子能量上进行研究。
