PIK3R1 negatively regulates the epithelial-mesenchymal transition and stem-like phenotype of renal cancer cells through the AKT/GSK3β/CTNNB1 signaling pathway

Sci Rep. 2015 Mar 11:5:8997. doi: 10.1038/srep08997.

Abstract

The phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway has been identified as an important pathway in renal cell carcinoma (RCC). We have reported a nonsense mutation in PIK3R1, which encodes the regulatory subunit of PI3K, in a metastatic RCC (mRCC), while the mutation was absent in the corresponding primary RCC (pRCC). To identify the function of PIK3R1 in RCC, we examined its expression in normal kidney, pRCC and mRCC by immunohistochemistry and real-time polymerase chain reaction. The expression of PIK3R1 significantly decreased in pRCC and was further reduced in mRCC compared with normal tissue. Besides, its expression levels were negatively correlated with T-category of tumor stage. Additionally, 786-O and A-704 cells with PIK3R1 depletion introduced by CRISPR/Cas9 system displayed enhanced proliferation, migration and epithelial-mesenchymal transition (EMT), and acquired a stem-like phenotype. Moreover, the PIK3R1 depletion promoted the phosphorylation of AKT in the cells. The knockdown of AKT by shRNA reduced p-GSK3β and CTNNB1 expression in the cells, while the depletion of CTNNB1 impaired stem-like phenotype of the cells. Overall, PIK3R1 down-regulation in RCC promotes propagation, migration, EMT and stem-like phenotype in renal cancer cells through the AKT/GSK3β/CTNNB1 pathway, and may contribute to progression and metastasis of RCC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • CRISPR-Cas Systems
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Cell Proliferation
  • Class Ia Phosphatidylinositol 3-Kinase
  • Disease Progression
  • Down-Regulation
  • Epithelial-Mesenchymal Transition* / genetics
  • Gene Knockout Techniques
  • Glycogen Synthase Kinase 3 / metabolism*
  • Glycogen Synthase Kinase 3 beta
  • Haplotypes
  • Humans
  • Kidney Neoplasms / genetics
  • Kidney Neoplasms / metabolism*
  • Kidney Neoplasms / pathology*
  • Neoplasm Metastasis
  • Neoplastic Stem Cells / metabolism
  • Phenotype
  • Phosphatidylinositol 3-Kinases / genetics
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Phosphorylation
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Signal Transduction*
  • Wnt Signaling Pathway
  • beta Catenin / metabolism*

Substances

  • CTNNB1 protein, human
  • beta Catenin
  • PIK3R1 protein, human
  • Class Ia Phosphatidylinositol 3-Kinase
  • GSK3B protein, human
  • Glycogen Synthase Kinase 3 beta
  • Proto-Oncogene Proteins c-akt
  • Glycogen Synthase Kinase 3