Combining radiation with autophagy inhibition enhances suppression of tumor growth and angiogenesis in esophageal cancer

Chen,Yongshun; Li,Xiaohong; Guo,Leiming; Wu,Xiaoyuan; He,Chunyu; Zhang,Song; Xiao,Yanjing; Yang,Yuanyuan; Hao,Daxuan

doi:10.3892/mmr.2015.3623

Combining radiation with autophagy inhibition enhances suppression of tumor growth and angiogenesis in esophageal cancer

Authors:
- Yongshun Chen
- Xiaohong Li
- Leiming Guo
- Xiaoyuan Wu
- Chunyu He
- Song Zhang
- Yanjing Xiao
- Yuanyuan Yang
- Daxuan Hao
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Affiliations: Department of Radiation Oncology, Zhengzhou University Affiliated Cancer Hospital, Henan Cancer Hospital, Zhengzhou, Henan 450008, P.R. China, Department of Pathology, Zhengzhou University Affiliated Cancer Hospital, Henan Cancer Hospital, Zhengzhou, Henan 450008, P.R. China, Department of Radiation Oncology, Zhengzhou People's Hospital, Zhengzhou, Henan 450053, P.R. China, Department of Pathology, Zhengzhou University Affiliated Zhengzhou Central Hospital, Zhengzhou, Henan 450003, P.R. China
Published online on: April 16, 2015 https://doi.org/10.3892/mmr.2015.3623
Pages: 1645-1652
Copyright: © Chen et al. This is an open access article distributed under the terms of Creative Commons Attribution License [CC BY_NC 3.0].

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Abstract

Radiotherapy is an effective treatment for esophageal cancer; however, tumor resistance to radiation remains a major biological problem. The present study aimed to investigate whether inhibition of autophagy may decrease overall tumor resistance to radiation. The effects of the autophagy inhibitor 3‑methyladenine (3‑MA) on radiosensitivity were tested in the EC9706 human esophageal squamous cell carcinoma cell line by colony formation assay. Furthermore, the synergistic cytotoxic effects of 3‑MA and radiation were assessed in a tumor xenograft model in nude mice. Mechanistic studies were performed using flow cytometry, immunohistochemistry and western blot analysis. The results of the present study demonstrated that radiation induced an accumulation of autophagosomes and 3‑MA effectively inhibited radiation‑induced autophagy. Inhibition of autophagy was shown to significantly increase the radiosensitivity of the tumors in vitro and in vivo. The enhancement ratio of sensitization in EC9706 cells was 1.76 when the cells were treated with 10 mM 3‑MA, alongside ionizing radiation. In addition, autophagy inhibition increased apoptosis and reduced tumor cell proliferation. The combination of radiation and autophagy inhibition resulted in a significant reduction in tumor volume and vasculature in the murine model. The present study demonstrated in vitro and in vivo that radiation‑induced autophagy has a protective effect against cell death, and inhibition of autophagy is able to enhance the radiosensitivity of esophageal squamous cell carcinoma.

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1	Jemal A, Bray F, Center MM, Ferlay J, Ward E and Forman D: Global cancer statistics. CA Cancer J Clin. 61:69–90. 2011. View Article : Google Scholar : PubMed/NCBI
2	Overgaard J: Hypoxic modification of radiotherapy in squamous cell carcinoma of the head and neck – a systematic review and meta-analysis. Radiother Oncol. 100:22–32. 2011. View Article : Google Scholar : PubMed/NCBI
3	Cooper JS, Guo MD, Herskovic A, et al: Chemoradiotherapy of locally advanced esophageal cancer: Long-term follow-up of a prospective randomized trial (RTOG 85-01). Radiation Therapy Oncology Group. JAMA. 281:1623–1627. 1999. View Article : Google Scholar : PubMed/NCBI
4	Zhu HW, Huo XD, Chen LY, Wang HH and Yu H: Clinical experience with radio-, chemo- and hyperthermotherapy combined trimodality on locally advanced esophageal cancer. Mol Clin Oncol. 1:1009–1012. 2013.
5	Suntharalingam M: Definitive chemoradiation in the management of locally advanced esophageal cancer. Semin Radiat Oncol. 17:22–28. 2007. View Article : Google Scholar
6	Tsuchihara K, Fujii S and Esumi H: Autophagy and cancer: Dynamism of the metabolism of tumor cells and tissues. Cancer Lett. 278:130–138. 2009. View Article : Google Scholar
7	Shimizu S, Yoshida T, Tsujioka M and Arakawa S: Autophagic cell death and cancer. Int J Mol Sci. 15:3145–3153. 2014. View Article : Google Scholar : PubMed/NCBI
8	Czarny P, Pawlowska E, Bialkowska-Warzecha J, Kaarniranta K and Blasiak J: Autophagy in DNA damage response. Int J Mol Sci. 16:2641–2662. 2015. View Article : Google Scholar : PubMed/NCBI
9	Eisenberg-Lerner A and Kimchi A: The paradox of autophagy and its implication in cancer etiology and therapy. Apoptosis. 14:376–391. 2009. View Article : Google Scholar : PubMed/NCBI
10	Brech A, Ahlquist T, Lothe RA and Stenmark H: Autophagy in tumour suppression and promotion. Mol Oncol. 3:366–375. 2009. View Article : Google Scholar : PubMed/NCBI
11	Stroikin Y, Dalen H, Lööf S and Terman A: Inhibition of autophagy with 3-methyladenine results in impaired turnover of lysosomes and accumulation of lipofuscin-like material. Eur J Cell Biol. 83:583–590. 2004. View Article : Google Scholar
12	Chen HY and White E: Role of autophagy in cancer prevention. Cancer Prev Res (Phila). 4:973–983. 2011. View Article : Google Scholar
13	Ramakrishnan S, Nguyen TM, Subramanian IV and Kelekar A: Autophagy and angiogenesis inhibition. Autophagy. 3:512–515. 2007. View Article : Google Scholar : PubMed/NCBI
14	Kumar S, Guru SK, Pathania AS, Kumar A, Bhushan S and Malik F: Autophagy triggered by magnolol derivative negatively regulates angiogenesis. Cell Death Dis. 4:e8892013. View Article : Google Scholar : PubMed/NCBI
15	Du J, Teng RJ, Guan T, Eis A, Kaul S, Konduri GG and Shi Y: Role of autophagy in angiogenesis in aortic endothelial cells. Am J Physiol Cell Physiol. 302:C383–C391. 2012. View Article : Google Scholar :
16	Shen W, Tian C, Chen H, Yang Y, Zhu D, Gao P and Liu J: Oxidative stress mediates chemerin-induced autophagy in endothelial cells. Free Radic Biol Med. 55:73–82. 2013. View Article : Google Scholar
17	Chen YS, Song HX, Lu Y, Li X, Chen T, Zhang Y, Xue JX, Liu H, Kan B, Yang G and Fu T: Autophagy inhibition contributes to radiation sensitization of esophageal squamous carcinoma cells. Dis Esophagus. 24:437–443. 2011. View Article : Google Scholar
18	Zhou GZ, Xu SL, Sun GC and Chen XB: Novel curcumin analogue IHCH exhibits potent anti proliferative effects by inducing autophagy in A549 lung cancer cells. Mol Med Rep. 10:441–446. 2014.PubMed/NCBI
19	Yuan H, Li AJ, Ma SL, Cui LJ, Wu B, Yin L and Wu MC: Inhibition of autophagy significantly enhances combination therapy with sorafenib and HDAC inhibitors for human hepatoma cells. World J Gastroenterol. 20:4953–4962. 2014. View Article : Google Scholar : PubMed/NCBI
20	Nakatogawa H, Ichimura Y and Ohsumi Y: Atg8, a ubiquitin-like protein required for autophagosome formation, mediates membrane tethering and hemifusion. Cell. 130:165–178. 2007. View Article : Google Scholar : PubMed/NCBI
21	Mizushima N, Yoshimori T and Levine B: Methods in mammalian autophagy research. Cell. 140:313–326. 2010. View Article : Google Scholar : PubMed/NCBI
22	Mac Gabbhan F, Qutub AA, Annex BH and Popel AS: Systems biology of pro-angiogenic therapies targeting the VEGF system. Wiley Interdiscip Rev Syst Biol Med. 2:694–707. 2010. View Article : Google Scholar
23	GLOBOCAN 2012: Estimated cancer incidence, mortality and prevalence worldwide in 2012. http://globocan.iarc.fr/Pages/fact_sheets_cancer.aspx. Accessed October 14, 2014.
24	Gwynne S, Hurt C, Evans M, Holden C, Vout L and Crosby T: Definitive chemoradiation for oesophageal cancer – a standard of care in patients with non-metastatic oseophageal cancer. Clin Oncol (R Coll Radiol). 23:182–188. 2011. View Article : Google Scholar
25	Shridhar R, Almhanna K, Meredith KL, Biagioli MC, Chuong MD, Cruz A and Hoffe SE: Radiation therapy and esophageal cancer. Cancer Control. 20:97–110. 2013.PubMed/NCBI
26	Welsh J, Settle SH, Amini A, Xiao L, Suzuki A, Hayashi Y, Hofstetter W, Komaki R, Liao Z and Ajani JA: Failure patterns in patients with esophageal cancer treated with definitive chemo-radiation. Cancer. 118:2632–2640. 2012. View Article : Google Scholar : PubMed/NCBI
27	Dewaele M, Maes H and Agostinis P: ROS-mediated mechanisms of autophagy stimulation and their relevance in cancer therapy. Autophagy. 6:838–854. 2010. View Article : Google Scholar : PubMed/NCBI
28	Wilkinson S and Ryan KM: Autophagy: An adaptable modifier of tumourigenesis. Curr Opin Genet Dev. 20:57–64. 2010. View Article : Google Scholar : PubMed/NCBI
29	Klionsky DJ, Abeliovich H, Agostinis P, Agrawal DK, Aliev G, Askew DS, et al: Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes. Autophagy. 4:151–175. 2008. View Article : Google Scholar : PubMed/NCBI
30	Benzina S, Altmeyer A, Malek F, et al: High-LET radiation combined with oxaliplatin induce autophagy in U-87 glioblastoma cells. Cancer Lett. 264:63–70. 2008. View Article : Google Scholar : PubMed/NCBI
31	Lomonaco SL, Finniss S, Xiang C, Decarvalho A, Umansky F, Kalkanis SN, Mikkelsen T and Brodie C: The induction of autophagy by gamma-radiation contributes to the radioresistance of glioma stem cells. Int J Cancer. 125:717–722. 2009. View Article : Google Scholar : PubMed/NCBI
32	Apel A, Herr I, Schwarz H, Rodemann HP and Mayer A: Blocked autophagy sensitizes resistant carcinoma cells to radiation therapy. Cancer Res. 68:1485–1494. 2008. View Article : Google Scholar : PubMed/NCBI
33	Moretti L, Cha YI, Niermann KJ and Lu B: Switch between apoptosis and autophagy: Radiation-induced endoplasmic reticulum stress? Cell Cycle. 6:793–798. 2007. View Article : Google Scholar : PubMed/NCBI
34	Chen YH, Pan SL, Wang JC, Kuo SH, Cheng JC and Teng CM: Radiation-induced VEGF-C expression and endothelial cell proliferation in lung cancer. Strahlenther Onkol. 190:1154–1162. 2014. View Article : Google Scholar : PubMed/NCBI
35	Yang YP, Hu LF, Zheng HF, Mao CJ, Hu WD, Xiong KP, Wang F and Liu CF: Application and interpretation of current autophagy inhibitors and activators. Acta Pharmacol Sin. 34:625–635. 2013. View Article : Google Scholar : PubMed/NCBI