Cripto-1 contributes to stemness in hepatocellular carcinoma by stabilizing Dishevelled-3 and activating Wnt/β-catenin pathway

Cell Death Differ. 2018 Aug;25(8):1426-1441. doi: 10.1038/s41418-018-0059-x. Epub 2018 Feb 14.

Abstract

Identification and characterization of functional molecular targets conferring stemness properties in hepatocellular carcinoma (HCC) offers crucial insights to overcome the major hurdles of tumor recurrence, metastasis and chemoresistance in clinical management. In the current study, we investigated the significance of Cripto-1 in contributing to HCC stemness. Cripto-1 was upregulated in the sorafenib-resistant clones derived from HCC cell lines and patient-derived xenograft that we previously developed, suggesting an association between Cripto-1 and stemness. By in vitro experiments, Cripto-1 fostered cell proliferation, migration, and invasion. It also enhanced self-renewal ability and conferred chemoresistance of HCC cells. Consistently, silencing of Cripto-1 suppressed in vivo tumorigenicity on serial transplantation. On the downstream signaling mechanism, expression of major components of Wnt/β-catenin pathway β-catenin, AXIN2, and C-MYC, accompanied by β-catenin activity was reduced upon Cripto-1 knockdown. The suppressive effects on stemness properties with Cripto-1 knockdown in vitro and in vivo were partially rescued by forced expression of constitutively active β-catenin. Further elucidation revealed the binding of Cripto-1 to Frizzled-7 (FZD7), low-density lipoprotein receptor-related protein 6 (LRP6) and Dishevelled-3 (DVL3) of the Wnt/β-catenin pathway and stabilized DVL3 protein. Analyses with clinical samples validated Cripto-1 overexpression in HCC tissues, as well as a positive correlation between Cripto-1 and AXIN2 expressions. High Cripto-1 level in tumor was associated with poorer disease-free survival of HCC patients. Taken together, Cripto-1 binds to FZD7/LRP6 and DVL3, stabilizes DVL3 expression and activates the Wnt/β-catenin signaling cascade to confer stemness in HCC. Our study findings substantiated the role of Cripto-1 in determining stemness phenotypes of HCC and mechanistically in modulating the Wnt/β-catenin signaling cascade, one of the most frequently deregulated pathways in liver cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Axin Protein / genetics
  • Axin Protein / metabolism
  • Carcinoma, Hepatocellular / metabolism
  • Carcinoma, Hepatocellular / pathology
  • Cell Line, Tumor
  • Dishevelled Proteins / chemistry
  • Dishevelled Proteins / metabolism*
  • Drug Resistance, Neoplasm / drug effects
  • Frizzled Receptors / chemistry
  • Frizzled Receptors / metabolism
  • GPI-Linked Proteins / antagonists & inhibitors
  • GPI-Linked Proteins / genetics
  • GPI-Linked Proteins / metabolism*
  • Humans
  • Intercellular Signaling Peptides and Proteins / genetics
  • Intercellular Signaling Peptides and Proteins / metabolism*
  • Liver Neoplasms / metabolism
  • Liver Neoplasms / pathology
  • Low Density Lipoprotein Receptor-Related Protein-6 / chemistry
  • Low Density Lipoprotein Receptor-Related Protein-6 / metabolism
  • Mice
  • Mice, Inbred NOD
  • Mice, SCID
  • Neoplasm Proteins / antagonists & inhibitors
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism*
  • Protein Binding
  • RNA Interference
  • RNA, Small Interfering / metabolism
  • Sorafenib / pharmacology
  • Wnt Signaling Pathway*
  • beta Catenin / metabolism*

Substances

  • AXIN2 protein, human
  • Axin Protein
  • DVL3 protein, human
  • Dishevelled Proteins
  • FZD7 protein, human
  • Frizzled Receptors
  • GPI-Linked Proteins
  • Intercellular Signaling Peptides and Proteins
  • LRP6 protein, human
  • Low Density Lipoprotein Receptor-Related Protein-6
  • Neoplasm Proteins
  • RNA, Small Interfering
  • TDGF1 protein, human
  • beta Catenin
  • Sorafenib