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T.H. Tseng



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    O12 - Lung Cancer Biology II (ID 87)

    • Event: WCLC 2013
    • Type: Oral Abstract Session
    • Track: Biology
    • Presentations: 1
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      O12.06 - Hedgehog/Gli Promotes Epithelial-Mesenchymal Transition in Non-Small Cell Lung Cancer (ID 2091)

      10:30 - 12:00  |  Author(s): T.H. Tseng

      • Abstract
      • Presentation
      • Slides

      Background
      A majority of non-small cell lung cancer (NSCLC) patients are diagnosed with metastatic phenotypes. Epithelial-to-Mesenchymal Transition (EMT), characterized by loss of epithelial markers, such as E-cadherin, is suggested to be involved in the metastatic process. In addition, aberrant activation of the Hedgehog-Gli(Hh/Gli) signaling pathway is implicated in various cancers, including NSCLC. We hypothesize that the Hh/Gli signaling pathway may regulate EMT in NSCLC, and inhibition of Hh/Gli pathway may provide a novel strategy to treat NSCLC and prevent metastasis.

      Methods
      Tumor tissues of 324 NSCLC patients were analyzed by immunohistochemistry for Gli and E-cadherin expression. Mechanistic studies were carried out in four NSCLC cell lines, A549, H1666, H2170 and H1703. Our lab has developed a novel small molecule Gli inhibitor (Gli-I )that effectively suppresses lung cancer in vitro and in vivo. Gli-I and a Smoothened inhibitor vismodegib were applied to suppress Hh/Gli signaling, while Hh protein was utilized to stimulate the pathway. Upon different treatments, EMT phenotypes were evaluated by wound healing assays and 3D cell invasion assays. Expression of EMT markers was measured by immunofluorescent staining and western blot at protein levels, as well as quantitative RT-PCR at mRNA levels.

      Results
      Our results demonstrated elevated Gli expression in 78% of NSCLC patient tissues. Gli expression was reversely correlated with E-Cadherin in patient tissues and culture cell lines. Inhibition of Hh signaling reduced cell migration and invasion, while stimulation of Hh signaling promoted EMT phenotypes. Specifically, Gli-I significantly suppressed cell proliferation, migration and invasion more effectively than vismodegib. Furthermore, mechanistic studied showed Hh/Gli signaling may regulate EMT through suppressing E-Cadherin.

      Conclusion
      Our results suggested that SHh/Gli signaling promotes cell proliferation and EMT, leading to NSCLC cell invasion and metastasis. Inhibition of Hh/Gli signaling by a novel Gli inhibitor Gli-I suppresses cell proliferation and invasion. Our novel Gli inhibitor holds the promise to provide an effective therapeutics to treat NSCLC and prevent metastasis.

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