Downregulation of Bmi-1 is associated with suppressed tumorigenesis and induced apoptosis in CD44+ nasopharyngeal carcinoma cancer stem-like cells

Xu,Xinhua; Liu,Yang; Su,Jin; Li,Daojun; Hu,Juan; Huang,Qiao; Lu,Mingqian; Liu,Xiaoyan; Ren,Jinghua; Chen,Weihong; Sun,Lidan

doi:10.3892/or.2015.4414

Downregulation of Bmi-1 is associated with suppressed tumorigenesis and induced apoptosis in CD44+ nasopharyngeal carcinoma cancer stem-like cells

Authors:
- Xinhua Xu
- Yang Liu
- Jin Su
- Daojun Li
- Juan Hu
- Qiao Huang
- Mingqian Lu
- Xiaoyan Liu
- Jinghua Ren
- Weihong Chen
- Lidan Sun
View Affiliations

Affiliations: The First College of Clinical Medical Science, China Three Gorges University and Department of Oncology, Yichang Central People's Hospital, Yichang, Hubei 443003, P.R. China, Oncology Institute, China Three Gorges University, Yichang, Hubei 443003, P.R. China, Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430023, P.R. China, Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, Department of Medical College, China Three Gorges University, Yichang, Hubei 443002, P.R. China
Published online on: November 12, 2015 https://doi.org/10.3892/or.2015.4414
Pages: 923-931

Metrics: Total Views: 0 (Spandidos Publications: | PMC Statistics: )

Metrics: Total PDF Downloads: 0 (Spandidos Publications: | PMC Statistics: )

Cited By (CrossRef): 0 citations Loading Articles...

Abstract

Bmi-1 (B-cell-specific Moloney murine leukemia virus insertion site 1) is a member of the Polycomb group gene (PcG) family, which is involved in the proliferation, migration and tumorigenesis of several types of cancer stem cells (CSCs). However, its precise role and mechanism in CD44+ nasopharyngeal carcinoma (NPC) cancer stem-like cells (CSC-LCs) remain poorly understood. In our previous study, we successfully silenced Bmi-1 by short hairpin RNA (shRNA) in CD44+ NPC CSC-LCs and obtained stable Bmi-1 knockdown (KD) cell lines. In the present study, we tested the cell proliferation by CCK-8 assay and apoptosis by ﬂow cytometry. Scratch wound healing assay, together with Transwell migration and invasion assays were used to measure the migration and invasion capacity. We further evaluated the tumorigenicity of CD44+ NPC CSC-LCs transfected with Bmi-1 shRNA in vivo. Based on our results, knockdown of Bmi-1 by shRNA resulted in the inhibition of tumor proliferation, migration and invasion in vitro, followed by cell apoptosis. In addition, our results preliminarily demonstrated that inhibition of Bmi-1 expression by shRNA increased tumor apoptosis through the p16INK4a-p14ARF-p53 pathway. Bmi-1 silencing in CD44+ NPC CSC-LCs also resulted in the failure to develop tumors in vivo. These results provide important insights into the role of Bmi-1 in the occurrence and development of NPC. Based on our findings, regulation of Bmi-1 in CD44+ NPC CSC-LCs may provide a potential molecular target for the therapy of NPC, and targeted silencing of Bmi-1 by shRNA may have clinical future implications in NPC therapy.

View Figures

View References

1	Lung ML, Cheung AK, KO JM, Lung HL, Cheng Y and Dai W: The interplay of host genetic factors and Epstein-Barr virus in the development of nasopharyngeal carcinoma. Chin J Cancer. 33:556–568. 2014. View Article : Google Scholar : PubMed/NCBI
2	Adham M, Kurniawan AN, Muhtadi AI, Roezin A, Hermani B, Gondhowiardjo S, Tan IB and Middeldorp JM: Nasopharyngeal carcinoma in Indonesia: Epidemiology, incidence, signs, and symptoms at presentation. Chin J Cancer. 31:185–196. 2012. View Article : Google Scholar : PubMed/NCBI
3	Lee AW, Lin JC and Ng WT: Current management of nasopharyngeal cancer. Semin Radiat Oncol. 22:233–244. 2012. View Article : Google Scholar : PubMed/NCBI
4	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
5	Li R, Wu X, Wei H and Tian S: Characterization of side population cells isolated from the gastric cancer cell line SGC-7901. Oncol Lett. 5:877–883. 2013.PubMed/NCBI
6	Wang S, Xu ZY, Wang LF and Su W: CD133⁺ cancer stem cells in lung cancer. Front Biosci (Landmark Ed). 18:447–453. 2013. View Article : Google Scholar
7	Cufi S, Corominas-Faja B, Vazquez-Martin A, Oliveras-Ferraros C, Dorca J, Bosch-Barrera J, Martin-Castillo B and Menendez JA: Metformin-induced preferential killing of breast cancer initiating CD44⁺CD24^−/low cells is sufficient to overcome primary resistance to trastuzumab in HER2⁺ human breast cancer xenografts. Oncotarget. 3:395–398. 2012. View Article : Google Scholar : PubMed/NCBI
8	Meng E, Long B, Sullivan P, McClellan S, Finan MA, Reed E, Shevde L and Rocconi RP: CD44⁺/CD24⁻ ovarian cancer cells demonstrate cancer stem cell properties and correlate to survival. Clin Exp Metastasis. 29:939–948. 2012. View Article : Google Scholar : PubMed/NCBI
9	Vasuri F, Resta L, Fittipaldi S, Malvi D and Pasquinelli G: RUNX-1 and CD44 as markers of resident stem cell derivation in undifferentiated intimal sarcoma of pulmonary artery. Histopathology. 61:737–743. 2012.PubMed/NCBI
10	Dhingra S, Feng W, Brown RE, Zhou Z, Khoury T, Zhang R and Tan D: Clinicopathologic significance of putative stem cell markers, CD44 and nestin, in gastric adenocarcinoma. Int J Clin Exp Pathol. 4:733–741. 2011.PubMed/NCBI
11	Rao GH, Liu HM, Li BW, Hao JJ, Yang YL, Wang MR, Wang XH, Wang J, Jin HJ, Du L, et al: Establishment of a human colorectal cancer cell line P6C with stem cell properties and resistance to chemotherapeutic drugs. Acta Pharmacol Sin. 34:793–804. 2013. View Article : Google Scholar : PubMed/NCBI
12	Shang Z, Cai Q, Zhang M, Zhu S, Ma Y, Sun L, Jiang N, Tian J, Niu X, Chen J, et al: A switch from CD44⁺ cell to EMT cell drives the metastasis of prostate cancer. Oncotarget. 6:1202–1216. 2015. View Article : Google Scholar
13	Prince ME, Sivanandan R, Kaczorowski A, Wolf GT, Kaplan MJ, Dalerba P, Weissman IL, Clarke MF and Ailles LE: Identification of a subpopulation of cells with cancer stem cell properties in head and neck squamous cell carcinoma. Proc Natl Acad Sci USA. 104:973–978. 2007. View Article : Google Scholar : PubMed/NCBI
14	Shigeishi H, Biddle A, Gammon L, Emich H, Rodini CO, Gemenetzidis E, Fazil B, Sugiyama M, Kamata N and Mackenzie IC: Maintenance of stem cell self-renewal in head and neck cancers requires actions of GSK3β influenced by CD44 and RHAMM. Stem Cells. 31:2073–2083. 2013. View Article : Google Scholar : PubMed/NCBI
15	Su J, Xu XH, Huang Q, Lu MQ, Li DJ, Xue F, Yi F, Ren JH and Wu YP: Identification of cancer stem-like CD44⁺ cells in human nasopharyngeal carcinoma cell line. Arch Med Res. 42:15–21. 2011. View Article : Google Scholar : PubMed/NCBI
16	Lun SW, Cheung ST, Cheung PF, To KF, Woo JK, Choy KW, Chow C, Cheung CC, Chung GT, Cheng AS, et al: CD44⁺ cancer stem-like cells in EBV-associated nasopharyngeal carcinoma. PLoS One. 7:e524262012. View Article : Google Scholar
17	Janisiewicz AM, Shin JH, Murillo-Sauca O, Kwok S, Le QT, Kong C, Kaplan MJ and Sunwoo JB: CD44(+) cells have cancer stem cell-like properties in nasopharyngeal carcinoma. Int Forum Allergy Rhinol. 2:465–470. 2012. View Article : Google Scholar : PubMed/NCBI
18	Siemens H, Jackstadt R, Kaller M and Hermeking H: Repression of c-Kit by p53 is mediated by miR-34 and is associated with reduced chemoresistance, migration and stemness. Oncotarget. 4:1399–1415. 2013. View Article : Google Scholar : PubMed/NCBI
19	Tong YQ, Liu B, Zheng HY, He YJ, Gu J, Li F and Li Y: Overexpression of BMI-1 is associated with poor prognosis in cervical cancer. Asia Pac J Clin Oncol. 8:e55–e62. 2012. View Article : Google Scholar : PubMed/NCBI
20	Bhattacharyya J, Mihara K, Ohtsubo M, Yasunaga S, Takei Y, Yanagihara K, Sakai A, Hoshi M, Takihara Y and Kimura A: Overexpression of BMI-1 correlates with drug resistance in B-cell lymphoma cells through the stabilization of survivin expression. Cancer Sci. 103:34–41. 2012. View Article : Google Scholar
21	Wu J, Hu D, Yang G, Zhou J, Yang C, Gao Y and Zhu Z: Down-regulation of BMI-1 cooperates with artemisinin on growth inhibition of nasopharyngeal carcinoma cells. J Cell Biochem. 112:1938–1948. 2011. View Article : Google Scholar : PubMed/NCBI
22	Lu H, Sun HZ, Li H and Cong M: The clinicopathological significance of Bmi-1 expression in pathogenesis and progression of gastric carcinomas. Asian Pac J Cancer Prev. 13:3437–3441. 2012. View Article : Google Scholar : PubMed/NCBI
23	Xu XH, Liu XY, Su J, Li DJ, Huang Q, Lu MQ, Yi F, Ren JH and Chen WH: shRNA targeting Bmi-1 sensitizes CD44⁺ nasopharyngeal cancer stem-like cells to radiotherapy. Oncol Rep. 32:764–770. 2014.PubMed/NCBI
24	Manoranjan B, Wang X, Hallett RM, Venugopal C, Mack SC, McFarlane N, Nolte SM, Scheinemann K, Gunnarsson T, Hassell JA, et al: FoxG1 interacts with Bmi1 to regulate self-renewal and tumorigenicity of medulloblastoma stem cells. Stem Cells. 31:1266–1277. 2013. View Article : Google Scholar : PubMed/NCBI
25	Lukacs RU, Memarzadeh S, Wu H and Witte ON: Bmi-1 is a crucial regulator of prostate stem cell self-renewal and malignant transformation. Cell Stem Cell. 7:682–693. 2010. View Article : Google Scholar : PubMed/NCBI
26	Proctor E, Waghray M, Lee CJ, Heidt DG, Yalamanchili M, Li C, Bednar F and Simeone DM: Bmi1 enhances tumorigenicity and cancer stem cell function in pancreatic adenocarcinoma. PLoS One. 8:e558202013. View Article : Google Scholar : PubMed/NCBI
27	Yao X, Wang X, Zhang S and Zhu H: Effects of Bmi-1 RNAi gene on laryngeal carcinoma Hep-2 cells. Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi. 26:550–557. 2012.In Chinese.
28	Chen YC, Chang CJ, Hsu HS, Chen YW, Tai LK, Tseng LM, Chiou GY, Chang SC, Kao SY, Chiou SH, et al: Inhibition of tumorigenicity and enhancement of radiochemosensitivity in head and neck squamous cell cancer-derived ALDH1-positive cells by knockdown of Bmi-1. Oral Oncol. 46:158–165. 2010. View Article : Google Scholar
29	Park IK, Qian D, Kiel M, Becker MW, Pihalja M, Weissman IL, Morrison SJ and Clarke MF: Bmi-1 is required for maintenance of adult self-renewing haematopoietic stem cells. Nature. 423:302–305. 2003. View Article : Google Scholar : PubMed/NCBI
30	Jiang Y, Su B, Meng X, Liu C, Liu B, Liu D, Fan Y and Yang H: Effect of siRNA-mediated silencing of Bmi-1 gene expression on HeLa cells. Cancer Sci. 101:379–386. 2010. View Article : Google Scholar
31	Zhu D, Wan X, Huang H, Chen X, Liang W, Zhao F, Lin T, Han J and Xie W: Knockdown of Bmi1 inhibits the stemness properties and tumorigenicity of human bladder cancer stem cell-like side population cells. Oncol Rep. 31:727–736. 2014.
32	Xu Z, Liu H, Lv X, Liu Y, Li S and Li H: Knockdown of the Bmi-1 oncogene inhibits cell proliferation and induces cell apoptosis and is involved in the decrease of Akt phosphorylation in the human breast carcinoma cell line MCF-7. Oncol Rep. 25:409–418. 2011.
33	Chen F, Li Y, Wang L and Hu L: Knockdown of BMI-1 causes cell-cycle arrest and derepresses p16^INK4a, HOXA9 and HOXC13 mRNA expression in HeLa cells. Med Oncol. 28:1201–1209. 2011. View Article : Google Scholar
34	Qin L, Zhang X, Zhang L, Feng Y, Weng GX, Li MZ, Kong QL, Qian CN, Zeng YX, Zeng MS, et al: Downregulation of BMI-1 enhances 5-fluorouracil-induced apoptosis in nasopharyngeal carcinoma cells. Biochem Biophys Res Commun. 371:531–535. 2008. View Article : Google Scholar : PubMed/NCBI
35	Jiang L, Song L, Wu J, Yang Y, Zhu X, Hu B, Cheng SY and Li M: Bmi-1 promotes glioma angiogenesis by activating NF-κB signaling. PLoS One. 8:e555272013. View Article : Google Scholar
36	Lindström MS, Klangby U and Wiman KG: p14^ARF homozygous deletion or MDM2 overexpression in Burkitt lymphoma lines carrying wild type p53. Oncogene. 20:2171–2177. 2001. View Article : Google Scholar
37	Molofsky AV, Pardal R, Iwashita T, Park IK, Clarke MF and Morrison SJ: Bmi-1 dependence distinguishes neural stem cell self-renewal from progenitor proliferation. Nature. 425:962–967. 2003. View Article : Google Scholar : PubMed/NCBI
38	Biehs B, Hu JK, Strauli NB, Sangiorgi E, Jung H, Heber RP, Ho S, Goodwin AF, Dasen JS, Capecchi MR, et al: BMI1 represses Ink4a/Arf and Hox genes to regulate stem cells in the rodent incisor. Nat Cell Biol. 15:846–852. 2013. View Article : Google Scholar : PubMed/NCBI
39	Yoshikawa R, Tsujimura T, Tao L, Kamikonya N and Fujiwara Y: The oncoprotein and stem cell renewal factor BMI1 associates with poor clinical outcome in oesophageal cancer patients undergoing preoperative chemoradiotherapy. BMC Cancer. 12:4612012. View Article : Google Scholar : PubMed/NCBI
40	Yao D, Wang Y, Xue L, Wang H, Zhang J and Zhang X: Different expression pattern and significance of p14^ARF-Mdm2-p53 pathway and Bmi-1 exist between gastric cardia and distal gastric adenocarcinoma. Hum Pathol. 44:844–851. 2013. View Article : Google Scholar