TGF-β1 induces epigenetic silence of TIP30 to promote tumor metastasis in esophageal carcinoma

Oncotarget. 2015 Feb 10;6(4):2120-33. doi: 10.18632/oncotarget.2940.

Abstract

TGF-β1, a potent EMT (epithelial-mesenchymal transition) inducer present in the tumor microenvironment, is involved in the metastasis and progression of various carcinomas, including esophageal squamous cell carcinoma (ESCC). TIP30 (30kDa HIV-1 Tat interacting protein) is a putative tumor metastasis suppressor. Here, we found TIP30 was decreased in cells undergoing EMT induced by TGF-β1, an occurrence that was related to promoter hypermethylation. TGF-β1 induced TIP30 hypermethylation via increasing DNMT1 and DNMT3A expression, which could be restored by TGF-β antibodies. In our in vitro and in vivo studies, we showed that silence of TIP30 led to EMT, enhanced migrative and invasive abilities of ESCC cells, promoted tumor metastasis in xenografted mice; alternatively, overexpression of TIP30 inhibited TGF-β1-induced EMT, and metastatic abilities of ESCC cells. Mechanically, TIP30 silencing induced the nuclear translocation and transcriptional activation of β-catenin in an AKT-dependent manner, which further resulted in the initiation of EMT. Consistently, TIP30 was frequently methylated and downregulated in ESCC patients. Loss of TIP30 correlated with nuclear β-catenin and aberrant E-cadherin expression. TIP30 was a powerful marker in predicting the prognosis of ESCC. Taken together, our results suggest a novel and critical role of TIP30 involved in TGF-β1-induced activation of AKT/β-catenin signaling and ESCC metastasis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetyltransferases / genetics*
  • Acetyltransferases / metabolism
  • Aged
  • Animals
  • Carcinoma, Squamous Cell / genetics*
  • Carcinoma, Squamous Cell / metabolism
  • Carcinoma, Squamous Cell / pathology
  • Cell Line, Tumor
  • DNA (Cytosine-5-)-Methyltransferase 1
  • DNA (Cytosine-5-)-Methyltransferases / genetics
  • DNA (Cytosine-5-)-Methyltransferases / metabolism
  • DNA Methylation / drug effects*
  • DNA Methyltransferase 3A
  • Epigenesis, Genetic / drug effects
  • Epithelial-Mesenchymal Transition / drug effects
  • Epithelial-Mesenchymal Transition / genetics
  • Esophageal Neoplasms / genetics*
  • Esophageal Neoplasms / metabolism
  • Esophageal Neoplasms / pathology
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Male
  • Mice, Inbred BALB C
  • Mice, Nude
  • Middle Aged
  • Neoplasm Metastasis
  • Prognosis
  • RNA Interference
  • Survival Analysis
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism
  • Transforming Growth Factor beta1 / metabolism
  • Transforming Growth Factor beta1 / pharmacology*
  • Transplantation, Heterologous
  • beta Catenin / genetics
  • beta Catenin / metabolism

Substances

  • DNMT3A protein, human
  • Dnmt3a protein, mouse
  • Transcription Factors
  • Transforming Growth Factor beta1
  • beta Catenin
  • DNA (Cytosine-5-)-Methyltransferase 1
  • DNA (Cytosine-5-)-Methyltransferases
  • DNA Methyltransferase 3A
  • DNMT1 protein, human
  • Dnmt1 protein, mouse
  • Acetyltransferases
  • HTATIP2 protein, human