Skip to main content

In vivo validation of metastasis-regulating microRNA-766 in human triple-negative breast cancer cells


Breast cancer is the second most common cancer and the most frequent cancer in women worldwide. Recent improvements in early detection and effective adjuvant chemotherapies have improved the survival of breast cancer patients. Even with initial disease remission, one-third of all breast cancer patients will relapse with distant metastasis. Breast cancer metastasis is largely an incurable disease and the main cause of death among breast cancer patients. Cancer metastasis is comprised of complex processes that are usually not controllable by intervention of a single molecular target. As a single microRNA (miRNA) can affect the aggressiveness of breast cancer cells by concurrently modulating multiple pathway effectors, a metastasis-regulating miRNA would represent a good disease target candidate. In this study, we evaluated the functional capacity of a newly defined human metastasis-related miRNA, miR-766, which was previously identified by comparing a patient-derived xenograft primary tumor model and a metastasis model. Compared to vector-transfected control cells, miR-766-overexpressed triple-negative breast cancer cells exhibited similar primary tumor growth in the orthotopic xenograft model. In contrast, tumor sphere formation and Matrigel invasion were significantly decreased in miR-766-overexpressed breast cancer cells compared with control cancer cells. In addition, lung metastasis was dramatically reduced in miR-766-overexpressed breast cancer cells compared with control cells. Thus, miR-766 affected the distant metastasis process to a greater extent than cancer cell proliferation and primary tumor growth, and may represent a future therapeutic target to effectively control fatal breast cancer metastasis.


  1. 1.

    American Cancer Society. Breast Cancer Facts & Figures 2011–2012. <>

  2. 2.

    Polyak K. Breast cancer: origins and evolution. J Clin Invest 2007; 117(11): 3155–3163.

    CAS  Article  Google Scholar 

  3. 3.

    Hornberger J, Alvarado M, Rebecca C, Gutierrez FIR, Yu T, Gradishar WJ. Clinical validity/utility, change in practice patterns, and economic implications of risk stratifiers to predict outcomes for early-stage breast cancer: a systematic review. J Natl Cancer Inst 2012; 104(14): 1068–1079.

    Article  Google Scholar 

  4. 4.

    Early Breast Cancer Trialists’ Collaborative Group (EBCTCG). Effects of chemotherapy and hormonal therapy for early breast cancer on recurrence and 15-year survival: an overview of the randomised trials. Lancet 2005; 365(9472): 1687–1717.

    Google Scholar 

  5. 5.

    El Saghir N, Tfayli A, Hatoum H, Nachef Z, Dinh P, Awada A. Treatment of metastatic breast cancer: state-of-the-art, subtypes and perspectives. Crit Rev Oncol Hematol 2011; 80(3): 433–449.

    Article  Google Scholar 

  6. 6.

    Eckhardt B, Francis P, Parker B, Anderson RL. Strategies for the discovery and development of therapies for metastatic breast cancer. Nat Rev Drug Discov 2012; 11(6): 479–497.

    CAS  Article  Google Scholar 

  7. 7.

    Oh K, Ko E, Kim H, Park A, Moon H, Noh D, Lee DS. Transglutaminase 2 facilitates the distant hematogenous metastasis of breast cancer by modulating interleukin-6 in cancer cells. Breast Cancer Res 2011; 13(5): R96.

    Google Scholar 

  8. 8.

    Oh K, Lee O, Shon S, Nam O, Ryu P, Seo M, Lee DS. A mutual activation loop between breast cancer cells and myeloid- derived suppressor cells facilitates spontaneous metastasis through IL-6 trans-signaling in a murine model. Breast Cancer Res 2013; 15(5): R79.

    Google Scholar 

  9. 9.

    Inui M, Martello G, Piccolo S. MicroRNA control of signal transduction. Nat Rev Mol Cell Biol 2010; 11(4): 252–263.

    CAS  Article  Google Scholar 

  10. 10.

    Bartel DP. MicroRNAs: target recognition and regulatory functions. Cell 2009; 136(2): 215–233.

    CAS  PubMed  Google Scholar 

  11. 11.

    Jonas S, Izaurralde E. Towards a molecular understanding of microRNA-mediated gene silencing. Nat Rev Genet 2015; 16(7): 421–433.

    CAS  Article  Google Scholar 

  12. 12.

    Nicoloso M, Spizzo R, Shimizu M, Rossi S, Calin GA. MicroRNAs—the micro steering wheel of tumour metastases. Nat Rev Cancer 2009; 9(4): 293–302.

    CAS  Article  Google Scholar 

  13. 13.

    Moon H, Oh K, Lee J, Lee M, Kim J, Yoo T, Seo M, Park A, Ryu H, Jung E, Kim N, Jeong S, Han W, Lee D, Noh DY. Prognostic and functional importance of the engraftment-associated genes in the patient-derived xenograft models of triple-negative breast cancers. Breast Cancer Res Treat 2015; 154(1): 13–22.

    Article  Google Scholar 

  14. 14.

    Ito M, Hiramatsu H, Kobayashi K, Suzue K, Kawahata M, Hioki K, Ueyama Y, Koyanagi Y, Sugamura K, Tsuji K, Heike T, Nakahata T. NOD/SCID/gamma(c)(null) mouse: an excellent recipient mouse model for engraftment of human cells. Blood 2002; 100(9): 3175–3182.

    CAS  PubMed  Google Scholar 

  15. 15.

    Perou C, Sørlie T, Eisen M, van de Rijn M, Jeffrey S, Rees C, Pollack J, Ross D, Johnsen H, Akslen L, Fluge O, Pergamenschikov A, Williams C, Zhu S, Lønning P, Borresen- Dale A, Brown P, Botstein D. Molecular portraits of human breast tumours. Nature 2000; 406(6797): 747–752.

    CAS  PubMed  Google Scholar 

  16. 16.

    Ahmad A. Pathways to breast cancer recurrence. ISRN Oncol 2013; 2013: 290568.

    PubMed  PubMed Central  Google Scholar 

  17. 17.

    Santos R, Ursu O, Gaulton A, Bento A, Donadi R, Bologa C, Karlsson A, Al-Lazikani B, Hersey A, Oprea T, Overington JR A comprehensive map of molecular drug targets. Nat Rev Drug Discov 2017; 16(1): 19–34.

    CAS  Article  Google Scholar 

  18. 18.

    Mimeault M, Batra SK. Altered gene products involved in the malignant reprogramming of cancer stem/progenitor cells and multitargeted therapies. Mol Aspects Med 2014; 39: 3–32.

    CAS  Article  Google Scholar 

  19. 19.

    Gandellini P, Doldi V, Zaffaroni N. microRNAs as players and signals in the metastatic cascade: Implications for the development of novel anti-metastatic therapies. Semin Cancer Biol 2017; 44: 132–140.

    CAS  Article  Google Scholar 

  20. 20.

    Rupaimoole R, Slack FJ. MicroRNA therapeutics: towards a new era for the management of cancer and other diseases. Nat Rev Drug Discov 2017; 16(3): 203–222.

    CAS  Article  Google Scholar 

  21. 21.

    Teoh S, Das S. The Role of MicroRNAs in Diagnosis, Prognosis, Metastasis and Resistant Cases in Breast Cancer. Curr Pharm Des 2017; 23(12): 1845–1859.

    CAS  Article  Google Scholar 

  22. 22.

    Kalluri R. The biology and function of fibroblasts in cancer. Nat Rev Cancer 2016; 16(9): 582–598.

    CAS  Article  Google Scholar 

  23. 23.

    Mantovani A, Marchesi F, Malesci A, Laghi L, Allavena P. Tumour-associated macrophages as treatment targets in oncology. Nat Rev Clin Oncol 2017; 14(7): 399–416.

    CAS  Article  Google Scholar 

  24. 24.

    Gabrilovich D, Ostrand-Rosenberg S, Bronte V. Coordinated regulation of myeloid cells by tumours. Nat Rev Immunol 2012; 12(4): 253–268.

    CAS  Article  Google Scholar 

  25. 25.

    Peinado H, Zhang H, Matei I, Costa-Silva B, Hoshino A, Rodrigues G, Psaila B, Kaplan R, Bromberg J, Kang Y, Bissell M, Cox T, Giaccia A, Erler J, Hiratsuka S, Ghajar C, Lyden D. Pre-metastatic niches: organ-specific homes for metastases. Nat Rev Cancer 2017; 17(5): 302–317.

    CAS  Article  Google Scholar 

  26. 26.

    Garzon R, Marcucci G, Croce CM. Targeting microRNAs in cancer: rationale, strategies and challenges. Nat Rev Drug Discov 2010; 9(10): 775–789.

    CAS  Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to Dong-Sup Lee.

Rights and permissions

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Oh, K., Lee, DS. In vivo validation of metastasis-regulating microRNA-766 in human triple-negative breast cancer cells. Lab Anim Res 33, 256–263 (2017).

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


  • Human triple-negative breast cancer
  • microRNA
  • metastasis