Tumor Biology

, Volume 37, Issue 7, pp 9671–9680 | Cite as

NANOG regulates epithelial-mesenchymal transition and chemoresistance through activation of the STAT3 pathway in epithelial ovarian cancer

  • Suqing Liu
  • Jing Sun
  • Bin Cai
  • Xiaowei Xi
  • Liu Yang
  • Zhenbo Zhang
  • Youji Feng
  • Yunyan Sun
Original Article


NANOG is a key transcription factor that is overexpressed and plays an important role in various cancers. Its overexpression is associated with highly tumorigenic, drug-resistant, and poor prognosis. However, the underlying mechanism of action of NANOG in ovarian cancer remains unclear. Epithelial-mesenchymal transition (EMT), which is a critical process in cancer invasion and metastasis, is also associated with drug resistance. We determined whether NANOG is associated with EMT and chemoresistance in epithelial ovarian cancer cells. NANOG expression was increased in epithelial ovarian cancer cells (HEY and SKOV3) compared with normal epithelial ovarian cells (Moody). Low expression of NANOG increased the expression of E-cadherin and decreased the expression of vimentin, β-catenin, and Snail. Furthermore, the cell migration and invasion abilities were decreased. The multidrug resistance genes MDR-1 and GST-π were also downregulated when NANOG was lowly expressed. The cells that were transfected with the si-NANOG plasmid were more sensitive to cisplatin compared with the cells that were transfected with empty vector. The data demonstrated that Stat3 was correlated with NANOG-mediated EMT and drug resistance. The silencing of Stat3 expression abrogated NANOG-mediated EMT changes and increased the sensitivity of the cells to chemotherapy. These results suggest that NANOG mediates EMT and drug resistance through activation of the Stat3 pathway in epithelial ovarian cancer.


NANOG EMT Chemoresistance Stat3 Ovarian cancer 



This study was funded by the Natural Science Foundation of Shanghai (12ZR1424300) and the National Natural Science Foundation (30600674).

Compliance with ethical standards

All procedures performed in studies involving human participants were in accordance with the ethical standards of institutional and national research committees, with the 1964 Declaration of Helsinki and its later amendments or with comparable ethical standards.

Conflicts of interest



  1. 1.
    Siegel R, Ma J, Zou Z, Jemal A. Cancer statistics, 2014. CA Cancer J Clin. 2014;64:9–29.CrossRefPubMedGoogle Scholar
  2. 2.
    Ozols RF. Treatment goals in ovarian cancer. Int J Gynecol Cancer. 2005;15 Suppl 1:3–11.CrossRefPubMedGoogle Scholar
  3. 3.
    Wang J, Rao S, Chu J, Shen X, Levasseur DN, Theunissen TW, et al. A protein interaction network for pluripotency of embryonic stem cells. Nature. 2006;444:364–8.CrossRefPubMedGoogle Scholar
  4. 4.
    Chambers I, Colby D, Robertson M, Nichols J, Lee S, Tweedie S, et al. Functional expression cloning of Nanog, a pluripotency sustaining factor in embryonic stem cells. Cell. 2003;113:643–55.CrossRefPubMedGoogle Scholar
  5. 5.
    Gillis AJ, Stoop H, Biermann K, van Gurp RJ, Swartzman E, Cribbes S, et al. Expression and interdependencies of pluripotency factors LIN28, OCT3/4, NANOG and SOX2 in human testicular germ cells and tumours of the testis. Int J Androl. 2011;34:e160–74.CrossRefPubMedGoogle Scholar
  6. 6.
    Shan J, Shen J, Liu L, Xia F, Xu C, Duan G, et al. Nanog regulates self-renewal of cancer stem cells through the insulin-like growth factor pathway in human hepatocellular carcinoma. Hepatology. 2012;56:1004–14.CrossRefPubMedGoogle Scholar
  7. 7.
    Chiou SH, Wang ML, Chou YT, Chen CJ, Hong CF, Hsieh WJ, et al. Coexpression of Oct4 and Nanog enhances malignancy in lung adenocarcinoma by inducing cancer stem cell-like properties and epithelial-mesenchymal transdifferentiation. Cancer Res. 2010;70:10433–44.CrossRefPubMedGoogle Scholar
  8. 8.
    Jeter CR, Liu B, Liu X, Chen X, Liu C, Calhoun-Davis T, et al. NANOG promotes cancer stem cell characteristics and prostate cancer resistance to androgen deprivation. Oncogene. 2011;30:3833–45.CrossRefPubMedPubMedCentralGoogle Scholar
  9. 9.
    Ezeh UI, Turek PJ, Reijo RA, Clark AT. Human embryonic stem cell genes OCT4, NANOG, STELLAR, and GDF3 are expressed in both seminoma and breast carcinoma. Cancer. 2005;104:2255–65.CrossRefPubMedGoogle Scholar
  10. 10.
    Wang D, Lu P, Zhang H, Luo M, Zhang X, Wei X, et al. Oct-4 and Nanog promote the epithelial-mesenchymal transition of breast cancer stem cells and are associated with poor prognosis in breast cancer patients. Oncotarget. 2014;5:10803–15.CrossRefPubMedPubMedCentralGoogle Scholar
  11. 11.
    Ding Y, Yu AQ, Li CL, Fang J, Zeng Y, Li DS. TALEN-mediated Nanog disruption results in less invasiveness, more chemosensitivity and reversal of EMT in Hela cells. Oncotarget. 2014;5:8393–401.CrossRefPubMedPubMedCentralGoogle Scholar
  12. 12.
    Gu TT, Liu SY, Zheng PS. Cytoplasmic NANOG-positive stromal cells promote human cervical cancer progression. Am J Pathol. 2012;181:652–61.CrossRefPubMedGoogle Scholar
  13. 13.
    Di J, Duiveman-de Boer T, Zusterzeel PL, Figdor CG, Massuger LF, Torensma R. The stem cell markers Oct4A, Nanog and c-Myc are expressed in ascites cells and tumor tissue of ovarian cancer patients. Cell Oncol. 2013;36:363–74.CrossRefGoogle Scholar
  14. 14.
    Pan Y, Jiao J, Zhou C, Cheng Q, Hu Y, Chen H. Nanog is highly expressed in ovarian serous cystadenocarcinoma and correlated with clinical stage and pathological grade. Pathobiology. 2010;77:283–8.CrossRefPubMedGoogle Scholar
  15. 15.
    Lee M, Nam EJ, Kim SW, Kim S, Kim JH, Kim YT. Prognostic impact of the cancer stem cell-related marker NANOG in ovarian serous carcinoma. Int J Gynecol Cancer. 2012;22:1489–96.CrossRefPubMedGoogle Scholar
  16. 16.
    Yadav A, Kumar B, Datta J, Teknos TN, Kumar P. IL-6 promotes head and neck tumor metastasis by inducing epithelial-mesenchymal transition via the JAK-STAT3-SNAIL signaling pathway. Mol Cancer Res. 2011;9:1658–67.CrossRefPubMedPubMedCentralGoogle Scholar
  17. 17.
    Yin X, Zhang BH, Zheng SS, Gao DM, Qiu SJ, Wu WZ, et al. Coexpression of gene Oct4 and Nanog initiates stem cell characteristics in hepatocellular carcinoma and promotes epithelial-mesenchymal transition through activation of Stat3/Snail signaling. J Hematol Oncol. 2015;8:23.CrossRefPubMedPubMedCentralGoogle Scholar
  18. 18.
    Bourguignon LY, Earle C, Wong G, Spevak CC, Krueger K. Stem cell marker (Nanog) and Stat-3 signaling promote MicroRNA-21 expression and chemoresistance in hyaluronan/CD44-activated head and neck squamous cell carcinoma cells. Oncogene. 2012;31:149–60.CrossRefPubMedGoogle Scholar
  19. 19.
    Chiu WT, Huang YF, Tsai HY, Chen CC, Chang CH, Huang SC, et al. FOXM1 confers to epithelial-mesenchymal transition, stemness and chemoresistance in epithelial ovarian carcinoma cells. Oncotarget. 2015;6:2349–65.CrossRefPubMedGoogle Scholar
  20. 20.
    Sun C, Sun L, Jiang K, Gao DM, Kang XN, Wang C, et al. NANOG promotes liver cancer cell invasion by inducing epithelial-mesenchymal transition through NODAL/SMAD3 signaling pathway. Int J Biochem Cell Biol. 2013;45:1099–108.CrossRefPubMedGoogle Scholar
  21. 21.
    Liu CW, Li CH, Peng YJ, Cheng YW, Chen HW, Liao PL, et al. Snail regulates Nanog status during the epithelial-mesenchymal transition via the Smad1/Akt/GSK3beta signaling pathway in non-small-cell lung cancer. Oncotarget. 2014;5:3880–94.CrossRefPubMedPubMedCentralGoogle Scholar
  22. 22.
    Dang H, Ding W, Emerson D, Rountree CB. Snail1 induces epithelial-to-mesenchymal transition and tumor initiating stem cell characteristics. BMC Cancer. 2011;11:396.CrossRefPubMedPubMedCentralGoogle Scholar
  23. 23.
    Zhang Z, Zhu Y, Lai Y, Wu X, Feng Z, Yu Y, et al. Follicle-stimulating hormone inhibits apoptosis in ovarian cancer cells by regulating the OCT4 stem cell signaling pathway. Int J Oncol. 2013;43:1194–204.PubMedPubMedCentralGoogle Scholar
  24. 24.
    Wei Y, Zhang Z, Liao H, Wu L, Wu X, Zhou D, et al. Nuclear estrogen receptor-mediated Notch signaling and GPR30-mediated PI3K/AKT signaling in the regulation of endometrial cancer cell proliferation. Oncol Rep. 2012;27:504–10.PubMedGoogle Scholar
  25. 25.
    Chiou SH, Yu CC, Huang CY, Lin SC, Liu CJ, Tsai TH, et al. Positive correlations of Oct-4 and Nanog in oral cancer stem-like cells and high-grade oral squamous cell carcinoma. Clin Cancer Res. 2008;14:4085–95.CrossRefPubMedGoogle Scholar
  26. 26.
    Tsai LL, Hu FW, Lee SS, Yu CH, Yu CC, Chang YC. Oct4 mediates tumor initiating properties in oral squamous cell carcinomas through the regulation of epithelial-mesenchymal transition. PLoS One. 2014;9:e87207.CrossRefPubMedPubMedCentralGoogle Scholar
  27. 27.
    Polyak K, Weinberg RA. Transitions between epithelial and mesenchymal states: acquisition of malignant and stem cell traits. Nat Rev Cancer. 2009;9:265–73.CrossRefPubMedGoogle Scholar
  28. 28.
    Cao W, Liu Y, Zhang R, Zhang B, Wang T, Zhu X, et al. Homoharringtonine induces apoptosis and inhibits STAT3 via IL-6/JAK1/STAT3 signal pathway in Gefitinib-resistant lung cancer cells. Sci Rep. 2015;5:8477.CrossRefPubMedPubMedCentralGoogle Scholar
  29. 29.
    Johnston PA, Sen M, Hua Y, Camarco DP, Shun TY, Lazo JS, et al. HCS campaign to identify selective inhibitors of IL-6-induced STAT3 pathway activation in head and neck cancer cell lines. Assay Drug Dev Technol. 2015;13:356–76.CrossRefPubMedPubMedCentralGoogle Scholar
  30. 30.
    Sanchez-Lopez E, Flashner-Abramson E, Shalapour S, Zhong Z, Taniguchi K, Levitzki A, Karin M. Targeting colorectal cancer via its microenvironment by inhibiting IGF-1 receptor-insulin receptor substrate and STAT3 signaling. Oncogene. 2015. doi: 10.1038/onc.2015.326.
  31. 31.
    Zhao H, Guo Y, Li S, Han R, Ying J, Zhu H, et al. A novel anti-cancer agent Icaritin suppresses hepatocellular carcinoma initiation and malignant growth through the IL-6/Jak2/Stat3 pathway. Oncotarget. 2015;6:31927–43.PubMedPubMedCentralGoogle Scholar
  32. 32.
    Jordan CT, Guzman ML, Noble M. Cancer stem cells. N Engl J Med. 2006;355:1253–61.CrossRefPubMedGoogle Scholar
  33. 33.
    Mani SA, Guo W, Liao MJ, Eaton EN, Ayyanan A, Zhou AY, et al. The epithelial-mesenchymal transition generates cells with properties of stem cells. Cell. 2008;133:704–15.CrossRefPubMedPubMedCentralGoogle Scholar
  34. 34.
    Scheel C, Weinberg RA. Cancer stem cells and epithelial-mesenchymal transition: concepts and molecular links. Semin Cancer Biol. 2012;22:396–403.CrossRefPubMedGoogle Scholar
  35. 35.
    Singh A, Settleman J. EMT, cancer stem cells and drug resistance: an emerging axis of evil in the war on cancer. Oncogene. 2010;29:4741–51.CrossRefPubMedPubMedCentralGoogle Scholar
  36. 36.
    Hu L, McArthur C, Jaffe RB. Ovarian cancer stem-like side-population cells are tumourigenic and chemoresistant. Br J Cancer. 2010;102:1276–83.CrossRefPubMedPubMedCentralGoogle Scholar
  37. 37.
    Kashyap V, Rezende NC, Scotland KB, Shaffer SM, Persson JL, Gudas LJ, et al. Regulation of stem cell pluripotency and differentiation involves a mutual regulatory circuit of the NANOG, OCT4, and SOX2 pluripotency transcription factors with polycomb repressive complexes and stem cell microRNAs. Stem Cells Dev. 2009;18:1093–108.CrossRefPubMedPubMedCentralGoogle Scholar
  38. 38.
    Siu MK, Wong ES, Kong DS, Chan HY, Jiang L, Wong OG, et al. Stem cell transcription factor NANOG controls cell migration and invasion via dysregulation of E-cadherin and FoxJ1 and contributes to adverse clinical outcome in ovarian cancers. Oncogene. 2013;32:3500–9.CrossRefPubMedGoogle Scholar
  39. 39.
    Goda K, Bacso Z, Szabo G. Multidrug resistance through the spectacle of P-glycoprotein. Curr Cancer Drug Targets. 2009;9:281–97.CrossRefPubMedGoogle Scholar
  40. 40.
    Lage H. MDR1/P-glycoprotein (ABCB1) as target for RNA interference-mediated reversal of multidrug resistance. Curr Drug Targets. 2006;7:813–21.CrossRefPubMedGoogle Scholar
  41. 41.
    Perez-Tomas R. Multidrug resistance: retrospect and prospects in anti-cancer drug treatment. Curr Med Chem. 2006;13:1859–76.CrossRefPubMedGoogle Scholar
  42. 42.
    He Y, Bi Y, Hua Y, Liu D, Wen S, Wang Q, et al. Ultrasound microbubble-mediated delivery of the siRNAs targeting MDR1 reduces drug resistance of yolk sac carcinoma L2 cells. J Exp Clin Cancer Res. 2011;30:104.CrossRefPubMedPubMedCentralGoogle Scholar
  43. 43.
    Lu D, Shi HC, Wang ZX, Gu XW, Zeng YJ. Multidrug resistance-associated biomarkers PGP, GST-pi, Topo-II and LRP as prognostic factors in primary ovarian carcinoma. Br J Biomed Sci. 2011;68:69–74.CrossRefPubMedGoogle Scholar
  44. 44.
    Latifi A, Abubaker K, Castrechini N, Ward AC, Liongue C, Dobill F, et al. Cisplatin treatment of primary and metastatic epithelial ovarian carcinomas generates residual cells with mesenchymal stem cell-like profile. J Cell Biochem. 2011;112:2850–64.CrossRefPubMedGoogle Scholar
  45. 45.
    Huang S. Regulation of metastases by signal transducer and activator of transcription 3 signaling pathway: clinical implications. Clin Cancer Res. 2007;13:1362–6.CrossRefPubMedGoogle Scholar
  46. 46.
    Silver DL, Naora H, Liu J, Cheng W, Montell DJ. Activated signal transducer and activator of transcription (STAT) 3: localization in focal adhesions and function in ovarian cancer cell motility. Cancer Res. 2004;64:3550–8.CrossRefPubMedGoogle Scholar
  47. 47.
    Bourguignon LY, Peyrollier K, Xia W, Gilad E. Hyaluronan-CD44 interaction activates stem cell marker Nanog, Stat-3-mediated MDR1 gene expression, and ankyrin-regulated multidrug efflux in breast and ovarian tumor cells. J Biol Chem. 2008;283:17635–51.CrossRefPubMedPubMedCentralGoogle Scholar
  48. 48.
    Wen Z, Zhong Z, Darnell Jr JE. Maximal activation of transcription by Stat1 and Stat3 requires both tyrosine and serine phosphorylation. Cell. 1995;82:241–50.CrossRefPubMedGoogle Scholar

Copyright information

© International Society of Oncology and BioMarkers (ISOBM) 2016

Authors and Affiliations

  • Suqing Liu
    • 1
  • Jing Sun
    • 1
  • Bin Cai
    • 1
  • Xiaowei Xi
    • 1
  • Liu Yang
    • 1
  • Zhenbo Zhang
    • 1
  • Youji Feng
    • 1
  • Yunyan Sun
    • 1
  1. 1.Department of Obstetrics and Gynecology, Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghaiChina

Personalised recommendations