Millimeter wave treatment induces apoptosis via activation of the mitochondrial-dependent pathway in human osteosarcoma cells.

Abstract

Millimeter wave (MW) is an electromagnetic wave with a wavelength between 1 and 10 mm and a frequency of 30-300 GHz that causes multiple biological effects and has been used as a major component in physiotherapies for the clinical treatment of various types of diseases including cancers. However, the precise molecular mechanism of the anticancer activity of millimeter wave remains to be elucidated. In the present study, we investigated the cellular effects of the MW in the U-2OS human osteosarcoma cell line. Our results showed that MW induced cell morphological changes and reduced cell viability in a dose- and time-dependent manner suggesting that MW inhibited the growth of U-2OS cells as demonstrated. Hoechst 33258 staining and Annexin V/propidium iodide double staining exhibited the typical nuclear features of apoptosis and increased the proportion of apoptotic Annexin V-positive cells in a dose-dependent manner, respectively. In addition, MW treatment caused loss of plasma membrane asymmetry, release of cytochrome c, collapse of mitochondrial membrane potential, activation of caspase-9 and -3, and increase of the ratio of pro-apoptotic Bax to anti-apoptotic Bcl-2. Taken together, the results indicate that the U-2OS cell growth inhibitory activity of MW was due to mitochondrial-mediated apoptosis, which may partly explain the anticancer activity of millimeter wave treatment.

• Authors: Guangwen Wu, Xuzheng Chen, Jun Peng, Qiaoyan Cai, Jinxia Ye, Huifeng Xu, Chunsong Zheng, Xihai Li, Hongzhi Ye, Xianxiang Liu
• Journal: International journal of oncology (Int J Oncol) Vol. 40 Issue 5 Pg. 1543-52 (May 2012) ISSN: 1791-2423 [Electronic] Greece
• PMID: 22246399 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Retracted Publication)

Chemical References

• BAX protein, human
• Proto-Oncogene Proteins c-bcl-2
• bcl-2-Associated X Protein
• Cytochromes c
• CASP3 protein, human
• CASP9 protein, human
• Caspase 3
• Caspase 9

Topics

• Apoptosis (radiation effects)
• Bone Neoplasms (metabolism, pathology)
• Caspase 3 (metabolism)
• Caspase 9 (metabolism)
• Cell Line, Tumor
• Cell Shape (radiation effects)
• Cell Survival (radiation effects)
• Cytochromes c (metabolism)
• Dose-Response Relationship, Radiation
• Electromagnetic Radiation
• Humans
• Membrane Potential, Mitochondrial (radiation effects)
• Mitochondria (metabolism, pathology, radiation effects)
• Osteosarcoma (metabolism, pathology)
• Proto-Oncogene Proteins c-bcl-2 (metabolism)
• Signal Transduction (radiation effects)
• Time Factors
• bcl-2-Associated X Protein (metabolism)