TRPP2 Enhances Metastasis by Regulating Epithelial-Mesenchymal Transition in Laryngeal Squamous Cell Carcinoma

Cell Physiol Biochem. 2016;39(6):2203-2215. doi: 10.1159/000447914. Epub 2016 Nov 7.

Abstract

Background/aim: Surgery and chemotherapy treatments of human laryngeal squamous cell carcinoma (HLSCC) may fail due to metastasis, in which epithelial-mesenchymal transition (EMT) plays an important role. TRPP2, a nonselective cation channel, is expressed in various cell types and participates in many biological processes. Here, we show that TRPP2 enhanced metastasis by regulating EMT.

Methods: We used immunohistochemistry, western blotting, Ca2+ imaging, transwell and wound healing assays to investigate TRPP2 expression levels in HLSCC tissue, and the role of TRPP2 in invasion and metastasis of a human laryngocarcinoma cell line (Hep2 cell).

Results: We found that TRPP2 protein expression levels were significantly increased in HLSCC tissue; higher TRPP2 levels were associated with decreased patient survival time and degree of differentiation and advanced clinical stage. Knockdown of TRPP2 by transfection with TRPP2 siRNA markedly suppressed ATP-induced Ca2+ release, wound healing, and cell invasion in Hep2 cells. Moreover, TRPP2 siRNA significantly decreased vimentin expression but increased E-cadherin expression in Hep2 cells. In the EMT signalling pathway, TRPP2 siRNA significantly decreased Smad4, STAT3, SNAIL, SLUG and TWIST expression in Hep2 cells.

Conclusion: We revealed a previously unknown function of TRPP2 in cancer development and a TRPP2-dependent mechanism underlying laryngocarcinoma cell invasion and metastasis. Our results suggest that TRPP2 may be used as a biomarker for evaluating patient prognosis and as a novel therapeutic target in HLSCC.

MeSH terms

  • Cadherins / metabolism
  • Calcium / metabolism
  • Carcinoma, Squamous Cell / genetics
  • Carcinoma, Squamous Cell / pathology*
  • Cell Line, Tumor
  • Cell Movement
  • Epithelial-Mesenchymal Transition*
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Immunohistochemistry
  • Laryngeal Neoplasms / genetics
  • Laryngeal Neoplasms / pathology*
  • Neoplasm Invasiveness
  • Neoplasm Metastasis
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism
  • RNA, Small Interfering / metabolism
  • STAT3 Transcription Factor / metabolism
  • Signal Transduction / genetics
  • Smad4 Protein / metabolism
  • Survival Analysis
  • TRPP Cation Channels / genetics
  • TRPP Cation Channels / metabolism*

Substances

  • Cadherins
  • Neoplasm Proteins
  • RNA, Small Interfering
  • STAT3 Transcription Factor
  • Smad4 Protein
  • TRPP Cation Channels
  • polycystic kidney disease 2 protein
  • Calcium