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Evidence-Based Complementary and Alternative Medicine
Volume 2013 (2013), Article ID 459271, 8 pages
http://dx.doi.org/10.1155/2013/459271
Research Article

Therapeutic and Radiosensitizing Effects of Armillaridin on Human Esophageal Cancer Cells

1Department of Medical Research, Mackay Memorial Hospital, Taipei 25160, Taiwan
2Department of Biotechnology, Hungkuang University, Taichung 43302, Taiwan
3Department of Radiation Oncology, Mackay Memorial Hospital, Taipei 10449, Taiwan
4Graduate Institute of Pharmacology, Taipei Medical University, Taipei 11031, Taiwan

Received 9 April 2013; Revised 1 June 2013; Accepted 2 June 2013

Academic Editor: Shrikant Anant

Copyright © 2013 Chih-Wen Chi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background. Armillaridin (AM) is isolated from Armillaria mellea. We examined the anticancer activity and radiosensitizing effect on human esophageal cancer cells. Methods. Human squamous cell carcinoma (CE81T/VGH and TE-2) and adenocarcinoma (BE-3 and SKGT-4) cell lines were cultured. The MTT assay was used for cell viability. The cell cycle was analyzed using propidium iodide staining. Mitochondrial transmembrane potential was measured by DiOC6(3) staining. The colony formation assay was performed for estimation of the radiation surviving fraction. Human CE81T/VGH xenografts were established for evaluation of therapeutic activity in vivo. Results. AM inhibited the viability of four human esophageal cancer cell lines with an estimated concentration of 50% inhibition (IC50) which was 3.4–6.9  M. AM induced a hypoploid cell population and morphological alterations typical of apoptosis in cells. This apoptosis induction was accompanied by a reduction of mitochondrial transmembrane potential. AM accumulated cell cycle at G2/M phase and enhanced the radiosensitivity in CE81T/VGH cells. In vivo, AM inhibited the growth of CE81T/VGH xenografts without significant impact on body weight and white blood cell counts. Conclusion. Armillaridin could inhibit growth and enhance radiosensitivity of human esophageal cancer cells. There might be potential to integrate AM with radiotherapy for esophageal cancer treatment.