JAK/STAT3 signaling is required for TGF-β-induced epithelial-mesenchymal transition in lung cancer cells

  • Authors:
    • Reng-Yun Liu
    • Yuanyuan Zeng
    • Zhe Lei
    • Longqiang Wang
    • Haiping Yang
    • Zeyi Liu
    • Jun Zhao
    • Hong-Tao Zhang
  • View Affiliations

  • Published online on: February 21, 2014     https://doi.org/10.3892/ijo.2014.2310
  • Pages: 1643-1651
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Abstract

Epithelial-mesenchymal transition (EMT), a key step in the early stages of cancer metastasis, is orchestrated by several signaling pathways, including IL-6/JAK/STAT3 and TGF-β/Smad signaling. However, an association between the two signaling pathways during the EMT process is largely unknown. Here, we focused on lung cancer and demonstrated that TGF-β1 induced the phosphorylation of Smad3 (p-Smad3), upregulation of Snail, a fibroblast-like morphology, and downregulation of E-cadherin as well as upregulation of vimentin in lung cancer cell lines. SIS3 (an inhibitor of Smad3) suppressed TGF-β1-induced activation of Smad3, upregulation of Snail and the EMT process. Importantly, the JAK2/STAT3-specific inhibitor AG490 blocked Stat3 phosphorylation, resulting in attenuated levels of TGF-β1-induced p-Smad3, Snail, MMP2, and Smad-mediated PAI-1 promoter reporter gene activity in A549 and H1650 cells. Subsequently, AG490 inhibited TGF-β-induced cell migration and invasion. Moreover, exogenous IL-6 treatment stimulated Stat3 activation, enhanced TGF-β-induced expression of p-Smad3 and Snail, aggravated the EMT process, and increased lung cancer cell migration and invasion induced by TGF-β1. Our findings show that the JAK/STAT3 pathway is required for TGF-β-induced EMT and cancer cell migration and invasion via upregulation of the expression of p-Smad3 and Snail, and the IL-6/JAK/STAT3 and TGF-β/Smad signaling synergistically enhance EMT in lung carcinomas. The present study suggests a novel rationale for inhibiting cancer metastasis using anti-IL-6/JAK/STAT3 and anti-TGF-β/Smad therapeutic strategies.
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May-2014
Volume 44 Issue 5

Print ISSN: 1019-6439
Online ISSN:1791-2423

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Spandidos Publications style
Liu R, Zeng Y, Lei Z, Wang L, Yang H, Liu Z, Zhao J and Zhang H: JAK/STAT3 signaling is required for TGF-β-induced epithelial-mesenchymal transition in lung cancer cells. Int J Oncol 44: 1643-1651, 2014
APA
Liu, R., Zeng, Y., Lei, Z., Wang, L., Yang, H., Liu, Z. ... Zhang, H. (2014). JAK/STAT3 signaling is required for TGF-β-induced epithelial-mesenchymal transition in lung cancer cells. International Journal of Oncology, 44, 1643-1651. https://doi.org/10.3892/ijo.2014.2310
MLA
Liu, R., Zeng, Y., Lei, Z., Wang, L., Yang, H., Liu, Z., Zhao, J., Zhang, H."JAK/STAT3 signaling is required for TGF-β-induced epithelial-mesenchymal transition in lung cancer cells". International Journal of Oncology 44.5 (2014): 1643-1651.
Chicago
Liu, R., Zeng, Y., Lei, Z., Wang, L., Yang, H., Liu, Z., Zhao, J., Zhang, H."JAK/STAT3 signaling is required for TGF-β-induced epithelial-mesenchymal transition in lung cancer cells". International Journal of Oncology 44, no. 5 (2014): 1643-1651. https://doi.org/10.3892/ijo.2014.2310