Research Article
Effects of HERV-R env Knockdown in Combination with Ionizing Radiation on Apoptosis-Related Gene Expression in A549 Lung Cancer Cells
Ja-Rang Lee1, Yi-Deun Jung2, Young-Hyun Kim1,3, Sang-Je Park1, Jae-Won Huh1,3* and Heui-Soo Kim4* | |
1National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju 363-883, Republic of Korea | |
2Stem Cell Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea | |
3University of Science and Technology, National Primate Research Center, KRIBB, Cheongju 363-883, Republic of Korea | |
4Department of Biological Sciences, College of Natural Sciences, Pusan National University, Busan, Republic of Korea | |
*Corresponding Authors: | Heui-Soo Kim Department of Biological Sciences College of Natural Sciences Pusan National University Busan 609-735, Korea Tel: +82-51-510-2259 Fax: +82-51-581-2962 E-mail: khs307@pusan.ac.kr |
Jae-Won Huh National Primate Research Center Korea Research Institute of Bioscience and Biotechnology Cheongju, Korea Tel: +82-43-240-6327 Fax: +82-43-240-6309 E-mail: huhjw@kribb.re.kr |
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Received January 07, 2016; Accepted February 23, 2016; Published March 01, 2016 | |
Citation: Lee JR, Jung YD, Kim YH, Park SJ, Huh JW, et al. (2016) Effects of HERV-R env Knockdown in Combination with Ionizing Radiation on Apoptosis- Related Gene Expression in A549 Lung Cancer Cells. Biochem Physiol 5:200. doi:10.4172/2168-9652.1000200 | |
Copyright: © 2016 Lee JR, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
Abstract
Radiotherapy has played a key role in the management of non–small-cell lung cancer (NSCLC). However, the use of radiotherapy in treating NSCLC is limited because of the intrinsic radiation resistance of tumor cells and injury to adjacent normal tissues. Many oncogenes are reported to be involved in radioresistance. Thus, novel moleculartargeting approaches to enhance the radiosensitivity of NSCLC cells are required to improve the therapeutic efficiency of radiotherapy. In this study, we report that expression of the human endogenous retrovirus-R (HERV-R) env gene is greatly elevated in γ-irradiation resistant A549 cells compared with radiation sensitive H460 cells. In addition, the HERV-R env gene was significantly increased in A549 cells after treatment with γ-irradiation. HERV-R env knockdown by siRNA in irradiated A549 cells led to overexpression of TP53 mRNA, followed by significant elevation in the levels of CDKN1A mRNA. Moreover, the expression of the apoptosis-related FAS-1 gene was increased, whereas the expression levels of the anti-apoptotic gene BCL2 were significantly decreased in the A549 cells in which the HERV-R env was suppressed by γ-irradiation. These results suggest that knockdown of HERV-R env with γ-irradiation causes cell cycle disturbances, which in turn induces apoptosis. In conclusion, the combination of HERV-R env knockdown and γ-irradiation has the potential to improve the therapeutic efficiency of radiotherapy for NSCLC.