RNAi-mediated knockdown of the c-jun gene sensitizes radioresistant human nasopharyngeal carcinoma cell line CNE-2R to radiation

Guo,Si-Yan; Zhu,Xiao-Dong; Ge,Lian-Ying; Qu,Song; Li,Ling; Su,Fang; Guo,Ya

doi:10.3892/or.2014.3692

RNAi-mediated knockdown of the c-jun gene sensitizes radioresistant human nasopharyngeal carcinoma cell line CNE-2R to radiation

Authors:
- Si-Yan Guo
- Xiao-Dong Zhu
- Lian-Ying Ge
- Song Qu
- Ling Li
- Fang Su
- Ya Guo
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Affiliations: Department of Radiation Oncology, The Affiliated Cancer Hospital of Guangxi Medical University, Cancer Institute of Guangxi Zhuang Autonomous Region, Nanning, Guangxi 530021, P.R. China, Department of Oncology, The Second Affiliated Hospital of Xian Jiaotong University, Xian, Shaanxi 710049, P.R. China
Published online on: December 22, 2014 https://doi.org/10.3892/or.2014.3692
Pages: 1155-1160

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Abstract

This study aimed to investigate the effect of RNA interference (RNAi)-mediated downregulation of the expression of the c-jun gene (a proto-oncogene) on the radiosensitivity of a radioresistant human nasopharyngeal carcinoma cell line (CNE-2R) and to validate its potential as an anticancer target. A lentiviral vector with c-jun small hairpin RNA (shRNA) was constructed and transfected into CNE-2R cells. The gene silencing efficiency of these recombinants was confirmed by RT-PCR and western blotting. Radiosensitivity, cell proliferation, cell cycle profile and apoptosis were assessed using colony formation assay, CCK-8 assay and flow cytometry, respectively. The lentiviral shRNA efficiently knocked down the expression of c-jun at both the mRNA and protein levels (P<0.05). c-jun-downregulated CNE-2R cells exhibited significantly decreased cell proliferation and enhanced radiosensitivity compared to the control group (P<0.05), and the effects were likely due to G2/M phase arrest and enhanced cell apoptosis. These data provide evidence that c-jun may be involved in the radioresistance of nasopharyngeal carcinoma (NPC) and knockdown of the c-jun gene may be a potential strategy to enhance the radiation sensitivity of NPC.

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1	Jia WH, Huang QH, Liao J, et al: Trends in incidence and mortality of nasopharyngeal carcinoma over a 20–25 year period (1978/1983–2002) in Sihui and Cangwu counties in southern China. BMC Cancer. 6:1782006. View Article : Google Scholar
2	Lee AW, Poon YF, Foo W, et al: Retrospective analysis of 5037 patients with nasopharyngeal carcinoma treated during 1976–1985: overall survival and patterns of failure. Int J Radiat Oncol Biol Phys. 23:261–270. 1992. View Article : Google Scholar
3	Leung SF, Teo PM, Shiu WW, Tsao SY and Leung TW: Clinical features and management of distant metastases of nasopharyngeal carcinoma. J Otolaryngol. 20:27–29. 1991.PubMed/NCBI
4	Shaulian E: AP-1 - The Jun proteins: Oncogenes or tumor suppressors in disguise? Cell Signal. 22:894–899. 2010. View Article : Google Scholar : PubMed/NCBI
5	Gao L, Huang S, Ren WH, et al: Jun activation domain-binding protein 1 expression in oral squamous cell carcinomas inversely correlates with the cell cycle inhibitor p27. Med Oncol. 29:2499–2504. 2012. View Article : Google Scholar : PubMed/NCBI
6	Song X, Tao YG, Deng XY, et al: Heterodimer formation between c-Jun and Jun B proteins mediated by Epstein-Barr virus encoded latent membrane protein 1. Cell Signal. 16:1153–1162. 2004. View Article : Google Scholar : PubMed/NCBI
7	Gonzalez-Villasana V, Gutierrez-Puente Y and Tari AM: Cyclooxygenase-2 utilizes Jun N-terminal kinases to induce invasion, but not tamoxifen resistance, in MCF-7 breast cancer cells. Oncol Rep. 30:1506–1510. 2013.PubMed/NCBI
8	Wang CY, Chen CL, Tseng YL, et al: Annexin A2 silencing induces G2 arrest of non-small cell lung cancer cells through p53-dependent and -independent mechanisms. J Biol Chem. 287:32512–32524. 2012. View Article : Google Scholar : PubMed/NCBI
9	Qing H, Gong W, Che Y, et al: PAK1-dependent MAPK pathway activation is required for colorectal cancer cell proliferation. Tumour Biol. 33:985–994. 2012. View Article : Google Scholar : PubMed/NCBI
10	Shimura T, Kakuda S, Ochiai Y, et al: Acquired radioresistance of human tumor cells by DNA-PK/AKT/GSK3beta-mediated cyclin D1 overexpression. Oncogene. 29:4826–4837. 2010. View Article : Google Scholar : PubMed/NCBI
11	Shimura T: Acquired radioresistance of cancer and the AKT/GSK3β/cyclin D1 overexpression cycle. J Radiat Res. 52:539–544. 2011. View Article : Google Scholar
12	Guo Y, Zhu XD, Qu S, et al: Identification of genes involved in radioresistance of nasopharyngeal carcinoma by integrating gene ontology and protein-protein interaction networks. Int J Oncol. 40:85–92. 2012.
13	Zhang JS, Li DM, Ma Y, et al: γ-Tocotrienol induces paraptosis-like cell death in human colon carcinoma SW620 cells. PLoS One. 8:e577792013. View Article : Google Scholar
14	Perri F, Bosso D, Buonerba C, Lorenzo GD and Scarpati GD: Locally advanced nasopharyngeal carcinoma: Current and emerging treatment strategies. World J Clin Oncol. 2:377–383. 2011. View Article : Google Scholar : PubMed/NCBI
15	Kikuchi J, Kinoshita I, Shimizu Y, et al: Simultaneous blockade of AP-1 and phosphatidylinositol 3-kinase pathway in non-small cell lung cancer cells. Br J Cancer. 99:2013–2019. 2008. View Article : Google Scholar : PubMed/NCBI
16	Kajanne R, Miettinen P, Tenhunen M and Leppä S: Transcription factor AP-1 promotes growth and radioresistance in prostate cancer cells. Int J Oncol. 35:1175–1182. 2009.PubMed/NCBI
17	Golding SE, Morgan RN, Adams BR, Hawkins AJ, Povirk LF and Valerie K: Pro-survival AKT and ERK signaling from EGFR and mutant EGFRvIII enhances DNA double-strand break repair in human glioma cells. Cancer Biol Ther. 8:730–738. 2009. View Article : Google Scholar : PubMed/NCBI
18	Hatanpaa KJ, Burma S, Zhao D and Habib AA: Epidermal growth factor receptor in glioma: signal transduction, neuropathology, imaging, and radioresistance. Neoplasia. 12:675–684. 2010.PubMed/NCBI
19	Grana TM, Sartor CI and Cox AD: Epidermal growth factor receptor autocrine signaling in RIE-1 cells transformed by the Ras oncogene enhances radiation resistance. Cancer Res. 63:7807–7814. 2003.PubMed/NCBI
20	Bergström JD, Westermark B and Heldin NE: Epidermal growth factor receptor signaling activates met in human anaplastic thyroid carcinoma cells. Exp Cell Res. 259:293–299. 2000. View Article : Google Scholar : PubMed/NCBI
21	Denning MF, Dlugosz AA, Cheng C, et al: Cross-talk between epidermal growth factor receptor and protein kinase C during calcium-induced differentiation of keratinocytes. Exp Dermatol. 9:192–199. 2000. View Article : Google Scholar : PubMed/NCBI
22	Izquierdo M: Short interfering RNAs as a tool for cancer gene therapy. Cancer Gene Ther. 12:217–227. 2005. View Article : Google Scholar
23	Pawlik TM and Keyomarsi K: Role of cell cycle in mediating sensitivity to radiotherapy. Int J Radiat Oncol Biol Phys. 59:928–942. 2004. View Article : Google Scholar : PubMed/NCBI
24	Shinomiya N: New concepts in radiation-induced apoptosis: ‘premitotic apoptosis’ and ‘postmitotic apoptosis’. J Cell Mol Med. 5:240–253. 2001. View Article : Google Scholar
25	Shi W, Bastianutto C, Li A, et al: Multiple dysregulated pathways in nasopharyngeal carcinoma revealed by gene expression profiling. Int J Cancer. 119:2467–2475. 2006. View Article : Google Scholar : PubMed/NCBI
26	Eferl R and Wagner EF: AP-1: a double-edged sword in tumorigenesis. Nat Rev Cancer. 3:859–868. 2003. View Article : Google Scholar : PubMed/NCBI
27	Shaulian E and Karin M: AP-1 as a regulator of cell life and death. Nat Cell Biol. 4:E131–E136. 2002. View Article : Google Scholar : PubMed/NCBI
28	Kutuk O, Poli G and Basaga H: Resveratrol protects against 4-hydroxynonenal-induced apoptosis by blocking JNK and c-JUN/AP-1 signaling. Toxicol Sci. 90:120–132. 2006. View Article : Google Scholar
29	Hu Z, Tao YG, Yang LF, et al: Effect of JIP on the proliferation and apoptosis of nasopharyngeal carcinoma cells. Ai Zheng. 21:1182–1186. 2002.(In Chinese).
30	Nateri AS, Spencer-Dene B and Behrens A: Interaction of phosphorylated c-Jun with TCF4 regulates intestinal cancer development. Nature. 437:281–285. 2005. View Article : Google Scholar : PubMed/NCBI
31	Su ZZ, Lee SG, Emdad L, et al: Cloning and characterization of SARI (suppressor of AP-1, regulated by IFN). Proc Natl Acad Sci USA. 105:20906–20911. 2008. View Article : Google Scholar : PubMed/NCBI