Integrin α6β4 Controls the Expression of Genes Associated with Cell Motility, Invasion, and Metastasis, Including S100A4/Metastasin

Abstract

The integrin ␣6␤4 is associated with carcinoma progression by contributing to apoptosis resistance, invasion, and metastasis, due in part to the activation of select transcription factors. To identify genes regulated by the ␣6␤4 integrin, we compared gene expression profiles of MDA-MB-435 cells that stably express integrin ␣6␤4 (MDA/␤4) and vector-only-transfected cells (MDA/mock) using Affymetrix GeneChip analysis. Our results show that integrin ␣6␤4 altered the expression of 538 genes (p < 0.01). Of these genes, 36 are associated with pathways implicated in cell motility and metastasis, including S100A4/ metastasin. S100A4 expression correlated well with integrin ␣6␤4 expression in established cell lines. Suppression of S100A4 by small interference RNA resulted in a reduced capacity of ␣6␤4-expressing cells to invade a reconstituted basement membrane in response to lysophosphatidic acid. Using small interference RNA, promoter analysis, and chromatin immunoprecipitation, we demonstrate that S100A4 is regulated by NFAT5, thus identifying the first target of NFAT5 in cancer. In addition, several genes that are known to be regulated by DNA methylation were up-regulated dramatically by integrin ␣6␤4 expression, including S100A4, FST, PDLIM4, CAPG, and Nkx2.2. Notably, inhibition of DNA methyltransferases stimulated expression of these genes in cells lacking the ␣6␤4 integrin, whereas demethylase inhibitors suppressed expression in ␣6␤4 integrin-expressing cells. Alterations in DNA methylation were confirmed by bisulfate sequencing, thus suggesting that integrin ␣6␤4 signaling can lead to the demethylation of select promoters. In summary, our data suggest that integrin ␣6␤4 confers a motile and invasive phenotype to breast carcinoma cells by regulating proinvasive and prometastatic gene expression.Integrins are receptors for the extracellular matrix, which have two major functions. The first is an adhesive function that secures cells to the surrounding extracellular matrix or, in the case of cell motility, provides traction for locomotion. Their second function is to transduce signals that are essential for cells to sense and integrate cues from the extracellular matrix, which include signals for directed cell motility, anchorage-dependent survival, and growth (1). As a result, integrin signaling and function are critical for most biological events in higher eukaryotes, both under normal and pathological conditions. In recent years, one integrin species, the ␣6␤4 integrin, has garnered much attention for its ability to promote an invasive and metastatic phenotype in carcinomas.In cells of epithelial origin, the integrin ␣6␤4 nucleates the formation of hemidesmosomes that link the cytokeratin cytoskeleton to the laminins found in the basement membrane, which are essential for epithelial integrity (2). During wound healing or the epithelial to mesenchymal transition (EMT), 2 the ␣6␤4 integrin is phosphorylated, is released from hemidesmosomes, and then binds the actin cytoskeleton (3). Under these conditions, the ␣6␤4...

Dual role of the ddx5/ddx17 RNA helicases in the control of the pro-migratory NFAT5 transcription factor

“…As expected, the depletion of NFAT5 decreased the S100A4 and LCN2 mRNA levels ( Figure 3a). In addition, chromatin immunoprecipitation (ChIP) assay using NFAT5 antibody indicated that NFAT5 was bound to the S100A4 and LCN2 promoters (Figure 3b, Supplementary Figure S3), as expected (Chen et al, 2009).…”

“…Regulation of NFAT5 by ddx5/ddx17 S Germann et al It has been reported that NFAT5 regulates the transcriptional activity of the S100A4 gene in a direct manner (Chen et al, 2009. S100A4 or metastasin, which is a member of the S100 family of calcium-binding proteins, has been shown to have an important role in breast cancer progression (Helfman et al, 2005;Garrett Regulation of NFAT5 by ddx5/ddx17 S Germann et al et al, 2006).…”

Integrin α6β4 Promotes Autocrine Epidermal Growth Factor Receptor (EGFR) Signaling to Stimulate Migration and Invasion toward Hepatocyte Growth Factor (HGF)

“…We have found that signaling through the integrin ␣6␤4 dramatically alters the transcriptome, leading to the up-regulation of key pro-invasion and metastatic genes such as autotaxin/ ENPP2 (9), S100A4 (10), and TIAM1 (11). In this study, we find that in pancreatic carcinoma cells the integrin ␣6␤4 stimulates the expression of AREG 2 and EREG, which are ligands for EGFR.…”

“…Furthermore, this integrin can promote pancreatic carcinoma invasiveness (11), in part through transcriptional regulation (10,11). Transcriptional profiling of integrin ␣6␤4-responsive genes (characterized in Ref.…”

High expression of integrin β6 in association with the Rho–Rac pathway identifies a poor prognostic subgroup within HER2 amplified breast cancers

“…A large body of evidence exists for the integrin‐mediated cell migration and invasion through activation of the Rho–Rac pathway 27, 28. To look for the probability of such an association in the clinical specimens, we assayed for the transcript abundance of the genes involved in this pathway.…”