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

MJ Larriba, E Martin-Villar, JM García, F Pereira… - …, 2009 - academic.oup.com
MJ Larriba, E Martin-Villar, JM García, F Pereira, C Pena, A Garcia de Herreros, F Bonilla…
Carcinogenesis, 2009academic.oup.com
Vitamin D receptor (VDR) mediates the antitumoral action of the active vitamin D metabolite
1α, 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 …
Abstract
Vitamin D receptor (VDR) mediates the antitumoral action of the active vitamin D metabolite 1α,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 β-catenin nuclear export and the antagonism of the transcriptional activity of β-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.
Oxford University Press