Electrochemical treatment of human KB cells in vitro

Yun Yen, Jian Ren Li, Bing Sen Zhou, Fernando Rojas, Jonathan Yu, C. K. Chou

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21 Citations (Scopus)

Abstract

Electrochemical treatment (ECT) of cancer is a promising new method by which direct current is delivered into tumor tissue to induce tumor regression. The purpose of this study is to evaluate the effectiveness of ECT on human cancer cells and to investigate the factors that affect ECT. The biological mechanisms of ECT in cancer treatment were also explored. Using human KB cells, ECT was found to delay cell growth by using 0.3 coulombs (C)/ml (1.5 C in 5 ml of culture medium; 3 V, 400 μA for 62.5 min). From the results of a colony-forming assay, it was clearly demonstrated that increasing the ECT dose decreases tumor cell survival. A cytotoxicity study, in which a methylene blue assay was used, determined that, for 2.5 × 105 cells in culture, the ID50 was 0.68 C/ml. For a fixed dose of 0.6 C/ml (3 C in 5 ml), using higher current and shorter treatment time resulted in better cell survival. Time, therefore, is an important factor. When cell concentration was altered, the survival was higher for increased cell concentrations. A thymidine incorporation assay indicated that the amount of [3H]thymidine incorporated into DNA decreased as the ECT dose increased. After treatment with 1 C/ml (5 C in 5 ml; 3 V, 400 μA for 208.4 min), pH at the anode decreased to 4.53 and at the cathode increased to 10.46. These results indicate that ECT is effective for killing human KB cells in vitro and that the toxicity effect is related to charge, current, and treatment time. The effect of pH alteration on cells is one of the mechanisms of ECT.

Original languageEnglish
Pages (from-to)34-41
Number of pages8
JournalBioelectromagnetics
Volume20
Issue number1
DOIs
Publication statusPublished - Dec 1 1999
Externally publishedYes

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Keywords

  • Clonogenic assay
  • Cytotoxicity
  • DNA synthesis
  • pH

ASJC Scopus subject areas

  • Biophysics
  • Physiology
  • Radiology Nuclear Medicine and imaging

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