Gastroenterology

Gastroenterology

Volume 144, Issue 7, June 2013, Pages 1530-1542.e12
Gastroenterology

Original Research
Full Report: Basic and Translational—Liver
Yes-Associated Protein Up-regulates Jagged-1 and Activates the NOTCH Pathway in Human Hepatocellular Carcinoma

https://doi.org/10.1053/j.gastro.2013.02.009Get rights and content

Background & Aims

Cancer cells often lose contact inhibition to undergo anchorage-independent proliferation and become resistant to apoptosis by inactivating the Hippo signaling pathway, resulting in activation of the transcriptional co-activator yes-associated protein (YAP). However, the oncogenic mechanisms of YAP activity are unclear.

Methods

By using cross-species analysis of expression data, the Notch ligand Jagged-1 (Jag-1) was identified as a downstream target of YAP in hepatocytes and hepatocellular carcinoma (HCC) cells. We analyzed the functions of YAP in HCC cells via overexpression and RNA silencing experiments. We used transgenic mice that overexpressed a constitutively activated form of YAP (YAPS127A), and measured protein levels in HCC, colorectal and pancreatic tumor samples from patients.

Results

Human HCC cell lines and mouse hepatocytes that overexpress YAPS127A up-regulated Jag-1, leading to activation of the Notch pathway and increased proliferation. Induction of Jag-1, activation of Notch, and cell proliferation required binding of YAP to its transcriptional partner TEA domain family member 4 (TEAD4); TEAD4 binding required the Mst1/2 but not β-catenin signaling. Levels of YAP correlated with Jag-1 expression and Notch signaling in human tumor samples and correlated with shorter survival times of patients with HCC or colorectal cancer.

Conclusions

The transcriptional regulator YAP up-regulates Jag-1 to activate Notch signaling in HCC cells and mouse hepatocytes. YAP-dependent activity of Jag-1 and Notch correlate in human HCC and colorectal tumor samples with patient survival times, suggesting the use of YAP and Notch inhibitors as therapeutics for gastrointestinal cancer. Transcript profiling: microarray information was deposited at the Gene Expression Omnibus database (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?token=jxepvsumwosqkve&acc=GSE35004).

Section snippets

Materials and Methods

For a detailed description of methods and antibodies used in this study see the Supplemental Materials and Methods section and Supplemental Table 1.

YAP Overexpression Supports HCC Cell Viability and Migration

Comprehensive immunohistochemical analysis of human specimens revealed weak/absent hepatocellular staining for nuclear or cytoplasmic YAP in normal or cirrhotic livers, dysplastic nodules, and hepatocellular adenomas (Supplementary Figure 1A). In contrast, nuclear YAP expression significantly increased in HCC, showing moderate to high expression in up to 67% of all cases (Supplementary Figure 1B and C). Nuclear YAP expression correlated with proliferation (Ki67 staining; r = 0.3; P < .001), but

Discussion

Accumulating evidence supports the importance of the tumor-suppressive Hippo pathway and its mediator YAP in cancer.1, 3, 4, 5, 6, 7, 12, 23 Here, we show that overexpression of YAP exerts its tumor-supporting properties partly through TEAD4-dependent Jag-1 expression and subsequent activation of the Notch pathway in gastrointestinal cancers. Our in vitro data provide evidence that YAP not only regulates proliferation and apoptosis but also affects cell migration in tumor cell lines of

Acknowledgments

The authors thank M. Bissinger, U. Müller, and S. Messnard for technical assistance; and T. R. Brummelkamp (Whitehead Institute for Biomedical Research, Cambridge, MA) and F. D. Camargo (Stem Cell Program, Children's Hospital, Boston, MA) for providing the Col1A1-YAPS127A mice.

References (36)

  • B. Zhao et al.

    The Hippo pathway in organ size control, tissue regeneration and stem cell self-renewal

    Nat Cell Biol

    (2011)
  • B. Zhao et al.

    Inactivation of YAP oncoprotein by the Hippo pathway is involved in cell contact inhibition and tissue growth control

    Genes Dev

    (2007)
  • M.Z. Xu et al.

    Yes-associated protein is an independent prognostic marker in hepatocellular carcinoma

    Cancer

    (2009)
  • K.P. Lee et al.

    The Hippo-Salvador pathway restrains hepatic oval cell proliferation, liver size, and liver tumorigenesis

    Proc Natl Acad Sci U S A

    (2010)
  • L. Lu et al.

    Hippo signaling is a potent in vivo growth and tumor suppressor pathway in the mammalian liver

    Proc Natl Acad Sci U S A

    (2010)
  • M.C. Cantarini et al.

    Aspartyl-asparagyl beta hydroxylase over-expression in human hepatoma is linked to activation of insulin-like growth factor and notch signaling mechanisms

    Hepatology

    (2006)
  • R. Qi et al.

    Notch1 signaling inhibits growth of human hepatocellular carcinoma through induction of cell cycle arrest and apoptosis

    Cancer Res

    (2003)
  • X.Q. Wang et al.

    Notch1-Snail1-E-cadherin pathway in metastatic hepatocellular carcinoma

    Int J Cancer

    (2012)
  • Cited by (267)

    • Anti-Jagged-1 immunotherapy in cancer

      2022, Advances in Medical Sciences
    • Hepatocarcinogenesis and the role of next-generation sequencing in liver cancer

      2022, Theranostics and Precision Medicine for the Management of Hepatocellular Carcinoma, Volume 2: Diagnosis, Therapeutic Targets, and Molecular Mechanisms
    View all citing articles on Scopus

    Conflicts of interest The authors disclose no conflicts.

    Funding This study was supported by grants from the Deutsche Forschungsgemeinschaft (SFB/TRR77 to K.B. and P.S., Ev168/2-1 to M.E., and Do622/2-1 to F.D.), the Helmholtz Alliance Immunotherapy of Cancer (P.S. and D.F.T.), the Virtual Liver Network (P.S. and K.B.), the Monika Kutzner Stiftung (D.F.T.), and National Institutes of Health R01CA136606 (X.C.). Also supported by the tissue bank of the National Center for Tumor Disease Heidelberg.

    §

    Authors share co-senior authorship.

    View full text