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Geon Oh, Yongha Gi, Heehun Sung, Jaehyun Seo, Hyunwoo Kim
Department of Bioengineering, Korea University, Seoul 02841,Republic of Korea
Yunhui Jo
Institute of Global Health Technology(IGHT), Korea University, Seoul 02841, Republic of Korea
Jaemin Lee
Department of Internal Medicine, Anam Hospital, Korea University College of Medicine, Seoul 02841, Republic of Korea
Myonggeun Yoon
FieldCure Ltd.,Seoul 02852, Republic of Korea
Department of Bioengineering, Korea University, Seoul, 02841, Republic of Korea
FieldCure Ltd, Seoul, 02481, Republic of Korea
Institute of Global Health Technology, Korea University, Seoul, 02841, Republic of Korea
J. Korean Phys. Soc. 81, 1020–1028 (2022).
Department of Bioengineering, Korea University, Seoul, Republic of Korea
Jong Hyun Kim & Myonggeun Yoon
FieldCure Ltd, Seoul, Republic of Korea
Institute of Global Health Technology, Korea University, Seoul, Republic of Korea
J. Korean Phys. Soc. 81, 1029–1038 (2022).
Background: Tumor-treating fields (TTFields) therapy is increasingly utilized clinically because of its demonstrated efficacy in cancer treatment. However, the risk of skin burns must still be reduced to improve patient safety and posttreatment quality of life.
Purpose: The purpose of this study was to evaluate the methods of constructing electrode arrays that reduce current density exceeding threshold values, which can cause skin burns during TTFields therapy.
Methods: Electrode and body models were generated using COMSOL software. The body model had the dielectric properties of the scalp. The average current density beneath the central region of the electrode was maintained at ∼31 mA/cm2 RMS. The deviations in current density at the edges of the electrode were reduced by three methods:adjustment of the ceramic thickness ratio of the center to the edge from 1/5 to 4/5, adjustment of the radius of the metal plate from 5.0 to 8.0 mm, and insertion of an insulator of width 0.5 to 2 mm at the edge.
Results: While using a single circular electrode, adjustment of the ceramic thickness ratio, adjustment of the metal plate radius, and insertion of an insulator near the edge reduced the deviations of current density by 14.6%, 67.7%, and 75.3%, respectively. Similarly, while using circular electrode arrays, inserting an insulator at the edge of each electrode reduced the deviations of current density significantly, from 8.62 to 2.40 mA/cm2.
Conclusions: Insertion of an insulator at the edge of each electrode was found to be the most effective method of attaining uniform current density distribution beneath the electrode, thereby lowering the risk of adverse effects of TTFields therapy.
Heehun Sung Geon Oh, Yongha Gi, Jaehyeon Seo
Department of Bioengineering, Korea University, Seoul,Republic of Korea
Institute of Global Health Technology (IGHT), Korea University, Seoul,Republic of Korea
Hyunwoo Kim, Sangmin Park, Myonggeun Yoon
FieldCure Ltd, Seoul,Republic of Korea
Med Phys. 2022;49:4837–4844.
Glioblastoma multiforme (GBM), the most common type of brain tumor, is a very aggressive and treatment-refractory cancer, with a 5-year survival rate of approximately 5%. Hyperthermia (HT) and tumor treating fields (TTF) therapy have been used to treat cancer, either alone or in combination with other treatment methods. Both treatments have been reported to increase the efficacy of other treatment techniques and to improve patient prognosis. The present study evaluated the therapeutic effects of combining HT and TTF on GBM cell lines. Cells were subjected to HT, TTF, HT+TTF, or neither treatment, followed by comparisons of cell proliferation, apoptosis, migration and invasiveness. Clonogenic assays showed that the two treatments had a synergistic effect. The levels of cleaved PARP and cleaved caspase-3 were higher and apoptosis was increased in cells treated with HT+TTF than in cells treated with HT or TTF alone. In addition, HT+TTF showed greater inhibition of GBM cell migration and invasiveness and greater downregulation of STAT3 than either HT or TTF alone. The stronger anticancer effect of HT+TTF suggested that this combination treatment can increase the survival rate of patients with difficult-to-treat cancers such as GBM.
Yunhui Jo, Young In Han
Institute of Global Health Technology (IGHT), Korea University, Seoul, Republic of Korea
Eunjun Lee, Geon Oh, Heehun Sung, Yongha Gi, Hyunwoo Kim, Sangmin Park
Department of Biomedical Engineering, Korea University, Seoul, Republic of Korea
Jaehyeon Seo
Department of Bioconvergence Engineering, Korea University, Seoul, Republic of Korea
Am J Cancer Res. 2022; 12(3): 1423–1432.
Background
Tumor-treating fields (TTFields) is an emerging non-invasive cancer-treatment modality using alternating electric fields with low intensities and an intermediate range of frequency. TTFields affects an extensive range of charged and polarizable cellular factors known to be involved in cell division. However, it causes side-effects, such as DNA damage and apoptosis, in healthy cells.
Objective
To investigate whether thymidine can have an effect on the DNA damage and apoptosis, we arrested the cell cycle of human glioblastoma cells (U373) at G1/S phase by using thymidine and then exposed these cells to TTFields.
Methods
Cancer cell lines and normal cell (HaCaT) were arrested by thymidine double block method. Cells were seeded into the gap of between the insulated wires. The exposed in alternative electric fields at 120 kHz, 1.2 V/cm. They were counted the cell numbers and analyzed for cancer malignant such as colony formation, Annexin V/PI staining, γH2AX and RT-PCR.
Results
The colony-forming ability and DNA damage of the control cells without thymidine treatment were significantly decreased, and the expression levels of BRCA1, PCNA, CDC25C, and MAD2 were distinctly increased. Interestingly, however, cells treated with thymidine did not change the colony formation, apoptosis, DNA damage, or gene expression pattern.
Conclusions
These results demonstrated that thymidine can inhibit the TTFields-caused DNA damage and apoptosis, suggesting that combining TTFields and conventional treatments, such as chemotherapy, may enhance prognosis and decrease side effects compared with those of TTFields or conventional treatments alone.
Hyesun Jeong, Sunghoi Hong
School of Biosystems and Biomedical Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
Department of Public Health Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
Yunhui Jo, Myonggeun Yoon
Department of Bio- Convergence Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
Genes Genom 43, 995–1001 (2021)