The nuclear transporter importin-11 regulates the Wnt/β-catenin pathway and acts as a tumor promoter in glioma

Int J Biol Macromol. 2021 Apr 15:176:145-156. doi: 10.1016/j.ijbiomac.2021.02.043. Epub 2021 Feb 8.

Abstract

Karyopherins mediate the macromolecular transport between the cytoplasm and the nucleus and participate in cancer progression. However, the role and mechanism of importin-11 (IPO11), a member of the karyopherin family, in glioma progression remain undefined. Effects of IPO11 on glioma progression were detected using CCK-8, colony formation assay, flow cytometry analysis, caspase-3 activity assay, and Transwell invasion assay. Western blot analysis was used to detect the expression of active caspase-3, active caspase-7, active caspase-9, N-cadherin, Vimentin, E-cadherin, β-catenin, and c-Myc. The activity of Wnt/β-catenin pathway was evaluated by the T-cell factor/lymphoid enhancer factor (TCF/LEF) transcription factor reporter assay. Results showed that IPO11 knockdown inhibited proliferation and reduced colony number in glioma cells. IPO11 silencing promoted the apoptotic rate, increased expression levels of active caspase-3, caspase-7, and caspase-9, and enhanced caspase-3 activity. Moreover, IPO11 silencing inhibited glioma cell invasion by suppressing epithelial-to-mesenchymal transition (EMT). Mechanistically, IPO11 knockdown inactivated the Wnt/β-catenin pathway. β-Catenin overexpression abolished the effects of IPO11 silencing on the proliferation, apoptosis, and invasion in glioma cells. Furthermore, IPO11 silencing blocked the malignant phenotypes and repressed the Wnt/β-catenin pathway in vivo. In conclusion, IPO11 knockdown suppressed the malignant phenotypes of glioma cells by inactivating the Wnt/β-catenin pathway.

Keywords: Glioma; IPO11; Tumor promoter; Wnt/β-catenin.

MeSH terms

  • Animals
  • Apoptosis / genetics
  • Apoptosis / physiology
  • Brain Neoplasms / genetics
  • Brain Neoplasms / metabolism*
  • Brain Neoplasms / pathology
  • Carcinogens / antagonists & inhibitors
  • Carcinogens / metabolism*
  • Cell Line, Tumor
  • Cell Proliferation / genetics
  • Cell Proliferation / physiology
  • Female
  • Gene Knockdown Techniques
  • Glioma / genetics
  • Glioma / metabolism*
  • Glioma / pathology
  • Heterografts
  • Humans
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Neoplasm Invasiveness / genetics
  • Neoplasm Invasiveness / pathology
  • Neoplasm Invasiveness / physiopathology
  • Phenotype
  • Transcriptome
  • Up-Regulation
  • Wnt Signaling Pathway
  • beta Catenin / genetics
  • beta Catenin / metabolism
  • beta Karyopherins / antagonists & inhibitors
  • beta Karyopherins / genetics
  • beta Karyopherins / metabolism*

Substances

  • CTNNB1 protein, human
  • Carcinogens
  • IPO11 protein, human
  • beta Catenin
  • beta Karyopherins