Radiotherapy Enhancement with Electroporation in Human Intestinal Colon Cancer HT-29 Cells

Abstract

Background: The efficiency of radiotherapy for tumors can be enhanced with different radiosensitizers. Previous<br />studies have shown that electroporation (EP) can sensitize some cancer cell lines to ionizing radiation (IR). HT-29<br />is a radiation resistant colorectal cancer cell line, representative of a cancer type which is the second cause of cancer<br />mortalities in developed countries. The present study aimed to evaluate radiosensitizing effects of EP on HT-29 cells<br />in vitro exposed to 6 MV X-ray photon beams. Methods: HT-29 cells were exposed to a 6 MV X-ray photon beam<br />as the control or to a combination of electroporation and irradiation. The response of cells was evaluated by colony<br />formation assay and survival curves. Results: The survival fraction of the HT-29 cells was significantly decreased by<br />electroporation prior to radiotherapy. A single electric pulse increased colorectal HT-29 cancer cell sensitivity to megavoltage<br />radiation by a factor of 1.36. Conclusion: Our findings showed that EP before radiotherapy can significantly<br />enhance tumor cell sensitivity. This combined treatment modality should be assessed for its applicability in clinic settings<br />for employment against radioresistant cancers. However, to facilitate achieving this goal, many different tumors with<br />a broad range of radiosensitivities should be evaluated.