Non-canonical Hedgehog signaling contributes to chemotaxis in cholangiocarcinoma

Nataliya Razumilava, Sergio A. Gradilone, Rory L. Smoot, Joachim C. Mertens, Steven F. Bronk, Alphonse E. Sirica, Gregory J. Gores

Research output: Contribution to journalArticle

42 Scopus citations

Abstract

Background & Aims The Hedgehog signaling pathway contributes to cholangiocarcinoma biology. However, canonical Hedgehog signaling requires cilia, and cholangiocarcinoma cells often do not express cilia. To resolve this paradox, we examined non-canonical (G-protein coupled, pertussis toxin sensitive) Hedgehog signaling in cholangiocarcinoma cells. Methods Human [non-malignant (H69), malignant (HuCC-T1 and Mz-ChA-1)] and rat [non-malignant (BDE1 and NRC), and malignant (BDEneu)] cell lines were employed for this study. A BDEΔLoop2 cell line with the dominant-negative receptor Patched-1 was generated with the Sleeping Beauty transposon transfection system. Results Cilia expression was readily identified in non-malignant, but not in malignant cholangiocarcinoma cell lines. Although the canonical Hh signaling pathway was markedly attenuated in cholangiocarcinoma cells, they were chemotactic to purmorphamine, a small-molecule direct Smoothened agonist. Purmorphamine also induced remodeling of the actin cytoskeleton with formation of filopodia and lamellipodia-like protrusions. All these biological features of cell migration were pertussis toxin sensitive, a feature of G-protein coupled (Gis) receptors. To further test the role of Hedgehog signaling in vivo, we employed a syngeneic orthotopic rat model of cholangiocarcinoma. In vivo, genetic inhibition of the Hedgehog signaling pathway employing BDE ΔLoop2 cells or pharmacological inhibition with a small-molecule antagonist of Smoothened, vismodegib, was tumor and metastasis suppressive. Conclusions Cholangiocarcinoma cells exhibit non-canonical Hedgehog signaling with chemotaxis despite impaired cilia expression. This non-canonical Hedgehog signaling pathway appears to contribute to cholangiocarcinoma progression, thereby, supporting a role for Hedgehog pathway inhibition in human cholangiocarcinoma.

Original languageEnglish (US)
Pages (from-to)599-605
Number of pages7
JournalJournal of hepatology
Volume60
Issue number3
DOIs
StatePublished - Mar 1 2014

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Keywords

  • Biliary tract cancer
  • Dominant-negative Ptch1
  • G-protein coupled receptor
  • Patched-1
  • Smoothened

ASJC Scopus subject areas

  • Hepatology

Cite this

Razumilava, N., Gradilone, S. A., Smoot, R. L., Mertens, J. C., Bronk, S. F., Sirica, A. E., & Gores, G. J. (2014). Non-canonical Hedgehog signaling contributes to chemotaxis in cholangiocarcinoma. Journal of hepatology, 60(3), 599-605. https://doi.org/10.1016/j.jhep.2013.11.005