• Open Access

MiR-21 regulates epithelial-mesenchymal transition phenotype and hypoxia-inducible factor-1α expression in third-sphere forming breast cancer stem cell-like cells

Authors

  • Mingli Han,

    1. Department of General Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
    2. The Key Laboratory of Laboratory Medical Diagnostics in the Ministry of Education, Chongqing Medical University, Chongqing, China
    3. Department of Clinical Biochemistry, Chongqing Medical University, Chongqing, China
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    • These authors contributed equally to this work.
  • Yimeng Wang,

    1. Department of Emergency, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
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    • These authors contributed equally to this work.
  • Manran Liu,

    1. The Key Laboratory of Laboratory Medical Diagnostics in the Ministry of Education, Chongqing Medical University, Chongqing, China
    2. Department of Clinical Biochemistry, Chongqing Medical University, Chongqing, China
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  • Xiaokai Bi,

    1. Department of General Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
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  • Junjie Bao,

    1. Department of General Surgery, Dazhou Central Hospital, Sichuan, China
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  • Ni Zeng,

    1. Department of General Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
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  • Zhikun Zhu,

    1. Department of General Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
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  • Zhiqiang Mo,

    1. Department of General Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
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  • Chengyi Wu,

    Corresponding author
    • Department of General Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
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  • Xin Chen

    Corresponding author
    • Department of General Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
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To whom correspondence should be addressed.

E-mail: wuchengyi1192@163.com; chenxin1192@126.com

Abstract

Cancer stem cells (CSCs) are predicted to be critical drivers of tumor progression due to their “stemness”, but the molecular mechanism of CSCs in regulating metastasis remains to be elucidated. Epithelial-mesenchymal transition (EMT), hypoxia-inducible factor (HIF)-1α, and miR-21, all of which contribute to cell migration for metastasis, are interrelated with CSCs. In the present study, third-sphere forming (3-S) CSC-like cells, which showed elevated CSC surface markers (ALDH1+ and CD44+/CD24−/low) and sphereforming capacity as well as migration and invasion capacities, were cultured and isolated from breast cancer MCF-7 parental cells, to evaluate the role of miR-21 in regulating the CSC-like cell biological features, especially EMT. EMT, which was assessed by overexpression of mesenchymal cell markers (N-cadherin, Vimentin, alpha-smooth muscle actin [α-SMA]) and suppression of epithelial cell marker (E-cadherin), was induced in 3-S CSC-like cells. Moreover, both of HIF-1α and miR-21 were upregulated in the CSC-like cells. Interestingly, antagonism of miR-21 by antagomir led to reversal of EMT, downexpression of HIF-1α, as well as suppression of invasion and migration, which indicates a key role of miR-21 involved in regulate CSC-associated features. In conclusion, we demonstrated that the formation of CSC-like cells undergoing process of EMT-like associated with overexpression of HIF-1α, both of which are regulated by miR-21. (Cancer Sci 2012; 103: 1058–1064)

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