An hTERT/ZEB1 complex directly regulates E-cadherin to promote epithelial-to-mesenchymal transition (EMT) in colorectal cancer

Oncotarget. 2016 Jan 5;7(1):351-61. doi: 10.18632/oncotarget.5968.

Abstract

In human cancer, high telomerase expression is correlated with tumor aggressiveness and metastatic potential. Telomerase activation occurs through telomerase reverse transcriptase (hTERT) induction, which contributes to malignant transformation by stabilizing telomeres. Previous studies have shown that hTERT can promote tumor invasion and metastasis of gastric cancer, liver cancer and esophageal cancer. Epithelial-to-mesenchymal transition (EMT), a requirement for tumor invasion and metastasis, plays a key role in cancer progression. Although hTERT promotes EMT through Wnt signaling in several cancers, it is unknown if other signaling pathways are involved. In the present study, we found that hTERT and ZEB1 form a complex, which directly binds to the E-cadherin promoter, and then inhibits E-cadherin expression and promots EMT in colorectal cancer cells. hTERT overexpression in HCT116 and SW480 cells could induce E-cadherin down-regulation. However, E-cadherin expression was recovered when ZEB1 function was impaired even during hTERT overexpression. Taken together, our findings suggest that hTERT can promote cancer metastasis by stimulating EMT through the ZEB1 pathway and therefore inhibiting them may prevent cancer progression.

Keywords: CRC; EMT; ZEB1; hTERT.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Cadherins / genetics*
  • Cadherins / metabolism
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Colorectal Neoplasms / genetics*
  • Colorectal Neoplasms / metabolism
  • Colorectal Neoplasms / pathology
  • Epithelial-Mesenchymal Transition / genetics*
  • Gene Expression Regulation, Neoplastic*
  • HCT116 Cells
  • Homeodomain Proteins / genetics*
  • Homeodomain Proteins / metabolism
  • Humans
  • Mice, Inbred BALB C
  • Mice, Inbred NOD
  • Mice, Nude
  • Mice, SCID
  • Microscopy, Fluorescence
  • Neoplasm Metastasis
  • Promoter Regions, Genetic / genetics
  • Protein Binding
  • RNA Interference
  • Reverse Transcriptase Polymerase Chain Reaction
  • Telomerase / genetics*
  • Telomerase / metabolism
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism
  • Transplantation, Heterologous
  • Zinc Finger E-box-Binding Homeobox 1

Substances

  • Cadherins
  • Homeodomain Proteins
  • Transcription Factors
  • ZEB1 protein, human
  • Zinc Finger E-box-Binding Homeobox 1
  • TERT protein, human
  • Telomerase