PSPC1-interchanged interactions with PTK6 and β-catenin synergize oncogenic subcellular translocations and tumor progression

Nat Commun. 2019 Dec 16;10(1):5716. doi: 10.1038/s41467-019-13665-6.

Abstract

Hepatocellular carcinoma (HCC) is one of the most lethal cancers worldwide due to metastasis. Paraspeckle component 1 (PSPC1) upregulation has been identified as an HCC pro-metastatic activator associated with poor patient prognosis, but with a lack of targeting strategy. Here, we report that PSPC1, a nuclear substrate of PTK6, sequesters PTK6 in the nucleus and loses its metastasis driving capability. Conversely, PSPC1 upregulation or PSPC1-Y523F mutation promotes epithelial-mesenchymal transition, stemness, and metastasis via cytoplasmic translocation of active PTK6 and nuclear translocation of β-catenin, which interacts with PSPC1 to augment Wnt3a autocrine signaling. The aberrant nucleocytoplasmic shuttling of active PTK6/β-catenin is reversed by expressing the PSPC1 C-terminal interacting domain (PSPC1-CT131), thereby suppressing PSPC1/PTK6/β-catenin-activated metastasis to prolong the survival of HCC orthotopic mice. Thus, PSPC1 is the contextual determinant of the oncogenic switch of PTK6/β-catenin subcellular localizations, and PSPC1-CT131 functions as a dual inhibitor of PSPC1 and PTK6 with potential for improving cancer therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Animals
  • Carcinoma, Hepatocellular / genetics
  • Carcinoma, Hepatocellular / mortality
  • Carcinoma, Hepatocellular / pathology*
  • Cell Line, Tumor
  • Cell Nucleus / metabolism
  • Cytoplasm / metabolism
  • Disease Progression
  • Epithelial-Mesenchymal Transition / genetics
  • Female
  • Humans
  • Kaplan-Meier Estimate
  • Liver / pathology
  • Liver Neoplasms / genetics
  • Liver Neoplasms / mortality
  • Liver Neoplasms / pathology*
  • Male
  • Mice
  • Middle Aged
  • Mutation
  • Neoplasm Proteins / metabolism*
  • Protein-Tyrosine Kinases / metabolism*
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • Signal Transduction
  • Up-Regulation
  • Wnt3A Protein / metabolism
  • Xenograft Model Antitumor Assays
  • Young Adult
  • beta Catenin / metabolism*

Substances

  • CTNNB1 protein, human
  • Neoplasm Proteins
  • PSPC1 protein, human
  • RNA-Binding Proteins
  • WNT3A protein, human
  • Wnt3A Protein
  • beta Catenin
  • Protein-Tyrosine Kinases
  • PTK6 protein, human