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Journal of Environmental Pathology, Toxicology and Oncology
IF: 1.241 5-Year IF: 1.349 SJR: 0.356 SNIP: 0.613 CiteScore™: 1.61

ISSN Print: 0731-8898
ISSN Online: 2162-6537

Journal of Environmental Pathology, Toxicology and Oncology

DOI: 10.1615/JEnvironPatholToxicolOncol.v24.i4.60
pages 291-298

Enhancement of Radiation Cytotoxicity in Murine Cancer Cells by Electroporation: In Vitro and In Vivo Studies

Pratip Shil
Biophysics Laboratory, Department of Physics, University of Pune, Pune 411007 India
Surendra H. Sanghvi
Radiation Biology & Health Sciences Division, Bhabha Atomic Research Center, Mumbai, India
Pandit B. Vidyasagar
Biophysics Laboratory, Department of Physics, University of Pune, Pune 411007 India
Kaushala Prasad Mishra
Department of Life Sciences, University of Mumbai, Mumbai, India; Nehru Gram Bharati University, Allahabad, UP, India; Foundation for Education and Research, India and BM International Research Centre, Mumbai, India


Increasing evidence has accumulated in recent years to suggest that the cell membrane forms the vital common target for action by ionizing radiation and electroporation. The present work describes the use of electric pulses for enhancement of radiation-induced cytotoxicity of cancer cells both in vitro and in vivo. In vitro: low dose rate (0.37 Gy/min) Co60 γ-rays (2 Gy) in combination with electric pulses of square wave (2 kV/cm, 200 μs duration, 8 pulses/burst, 10 times) significantly enhanced the cytotoxicity in Ehrlich ascites carcinoma cells (EAC), probably through enhanced production of intracellular reactive oxygen species (ROS).The intracellular generation of ROS and changes in oxidative damage-mediated membrane fluidity were determined by fluorescence using DCH-FDA and DPH, respectively, as probes. Both radiation and electroporation, separately, have been observed to produce ROS in a dose-dependent fashion. We show that the combined treatment of cells with radiation and electroporation significantly increased intracellular ROS and changed membrane fluidity of EAC cells as compared to the effects by each individual treatment. In vivo studies have been carried out with murine fibrosarcoma as a model system. The localized treatment of a fibrosarcoma tumor, grown in the right hind leg of Swiss mice, had been carried out using radiation (Co60 γ-rays, 2 Gy, dose rate: 0.37 Gy /min) and electric pulses (1 kV/cm, 200 μs, 8 pulses/burst, 10 times). Studies on tumor growth kinetics have shown a significant growth delay (by 50% to that of control) 7 days after treatment of tumor with radiation and electroporation. The results suggest that radiocytotoxicity of tumor cells in vitro as well as in vivo were enhanced significantly by electric pulses, which may offer a potentially improved treatment of cancer.