Snail2 cooperates with Snail1 in the repression of vitamin D receptor in colon cancer

Carcinogenesis. 2009 Aug;30(8):1459-68. doi: 10.1093/carcin/bgp140. Epub 2009 Jun 5.

Abstract

Vitamin D receptor (VDR) mediates the antitumoral action of the active vitamin D metabolite 1alpha,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)). VDR expression is lost during colon cancer progression causing unresponsiveness to 1,25(OH)(2)D(3) and its analogs. Previously, Snail1, an inducer of epithelial-to-mesenchymal transition (EMT), was reported to inhibit VDR expression. Here, we show that Snail2/Slug, but not other EMT inducers such as Zeb1, Zeb2, E47 or Twist1, represses VDR gene promoter. Moreover, Snail2 and Snail1 show additive repressing effect on VDR promoter. Snail2 inhibits VDR RNA and protein and blocks the induction of E-cadherin and an adhesive phenotype by 1,25(OH)(2)D(3). Snail2 reduces the ligand-induced VDR transcriptional activation of a consensus response element and of the CYP24 promoter. Concordantly, Snail2 inhibits the induction of CYP24 RNA and p21(CIP1), filamin A and vinculin proteins and the repression of c-MYC by 1,25(OH)(2)D(3). Additionally, Snail2 abrogates beta-catenin nuclear export and the antagonism of the transcriptional activity of beta-catenin-T-cell factor complexes by 1,25(OH)(2)D(3). SNAI2 expression is upregulated in 58% of colorectal tumors and correlates inversely with that of VDR. However, VDR downregulation is higher in tumors coexpressing SNAI2 and SNAI1 than in those expressing only one of these genes. Together, these data indicate that Snail2 and Snail1 cooperate for VDR repression in colon cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / genetics
  • Adenocarcinoma / metabolism*
  • Adenocarcinoma / secondary
  • Blotting, Western
  • Cadherins / genetics
  • Cadherins / metabolism
  • Colorectal Neoplasms / genetics
  • Colorectal Neoplasms / metabolism*
  • Colorectal Neoplasms / pathology*
  • Fluorescent Antibody Technique
  • Humans
  • Immunoenzyme Techniques
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Promoter Regions, Genetic
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Receptors, Calcitriol / antagonists & inhibitors
  • Receptors, Calcitriol / genetics*
  • Receptors, Calcitriol / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction
  • Snail Family Transcription Factors
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Transcription, Genetic*
  • Twist-Related Protein 1 / genetics
  • Twist-Related Protein 1 / metabolism
  • Vitamin D / analogs & derivatives
  • Vitamin D / pharmacology
  • Wnt Proteins / genetics
  • Wnt Proteins / metabolism
  • beta Catenin / genetics
  • beta Catenin / metabolism

Substances

  • Cadherins
  • Nuclear Proteins
  • RNA, Messenger
  • Receptors, Calcitriol
  • SNAI1 protein, human
  • SNAI2 protein, human
  • Snail Family Transcription Factors
  • TWIST1 protein, human
  • Transcription Factors
  • Twist-Related Protein 1
  • Wnt Proteins
  • beta Catenin
  • dihydroxy-vitamin D3
  • Vitamin D