7474

WNT5A

We have shown that Wnt5A increases the motility of melanoma cells. To explore cellular pathways involving Wnt5A, we compared gain-of-function (WNT5A stable transfectants) versus loss-of-function (siRNA knockdown) of WNT5A by microarray analysis. Increasing WNT5A suppressed the expression of several genes, which were re-expressed after small interference RNA-mediated knockdown of WNT5A. Genes affected by WNT5A include KISS-1, a metastasis suppressor, and CD44, involved in tumor cell homing during metastasis. This could be validated at the protein level using both small interference RNA and recombinant Wnt5A (rWnt5A). Among the genes up-regulated by WNT5A was the gene vimentin, associated with an epithelial to mesenchymal transition (EMT), which involves decreases in E-cadherin, due to up-regulation of the transcriptional repressor, Snail. rWnt5A treatment increases Snail and vimentin expression, and decreases E-cadherin, even in the presence of dominant-negativeTCF4, suggesting that this activation is independent of Wnt/beta-catenin signaling. Because Wnt5A can signal via protein kinase C (PKC), the role of PKC in Wnt5A-mediated motility and EMT was also assessed using PKC inhibition and activation studies. Treating cells expressing low levels of Wnt5A with phorbol ester increased Snail expression inhibiting PKC in cells expressing high levels of Wnt5A decreased Snail. Furthermore, inhibition of PKC before Wnt5A treatment blocked Snail expression, implying that Wnt5A can potentiate melanoma metastasis via the induction of EMT in a PKC-dependent manner.

By mining DNA microarray data bases at GenBank, we identified up-regulation of membrane type 1 matrix metalloproteinase (MT1-MMP) in human primary and metastatic prostate cancer specimens as compared with nonmalignant prostate tissues. To explore the role of up-regulated MT1-MMP in early stage cancer progression, we have employed a three-dimensional cell culture model. Minimally invasive human prostate cancer cells (LNCaP) were transfected with MT1-green fluorescent protein (GFP) chimeric cDNA as compared with GFP cDNA, and morphologic and phenotypic changes were characterized. GFP-expressing LNCaP cells formed multicellular spheroids with cuboidal-like epithelial morphology, whereas MT1-GFP-expressing cells displayed a fibroblast-like morphology and a scattered growth pattern in type I collagen gels. Cell morphologic changes were accompanied by decreased epithelial markers and enhanced mesenchymal markers, consistent with epithelial-to-mesenchymal transition. MT1-MMP-induced morphologic change and cell scattering were abrogated by target inhibition of either the catalytic domain or the hemopexin domain. We further demonstrated that MT1-MMP-induced phenotypic changes were dependent upon up-regulation of Wnt5a, which has been implicated in epithelial-to-mesenchymal transition. We conclude that MT1-MMP plays an important role in early cancer dissemination by converting epithelial cells to migratory mesenchymal-like cells.

expression of Snail has been shown to mediate epithelial-mesenchymal transition (EMT) of epithelial cells and carcinomas, characterized by morphological alterations with disappearance and appearance of E-cadherin and vimentin, respectively. Here, we show that ectopic expression of Snail in human epidermoid carcinoma A431 cells (Snail/A431) induces the representative EMT, resulting in remarkable motile and invasive properties of the cells. expression of Wnt5a, its receptor Ror2 and matrix metalloproteinase (MMP)-2 is induced in Snail/A431, but not in control A431 cells. Interestingly, suppressed expression of either Wnt5a or Ror2 in Snail/A431 cells results in the inhibition of in vitro cell motility and invasiveness, at least partly mediated by MMP-2, without affecting characteristics of EMT, i.e., mesenchymal morphology, and down- and up-regulations of E-cadherin and vimentin, respectively. We further show that endogenous Snail is required for sustained expression of Wnt5a, Ror2 and MMP-13 in human osteosarcoma SaOS-2 cells. The results indicate that expression of both Wnt5a and Ror2 is induced during Snail-mediated EMT or malignant progression of cancer cells and that consequently activated Wnt5a-Ror2 signaling confers highly motile and invasive properties on cancer cells. Thus, Wnt5a-Ror2 signaling can be a target of cancer therapies to prevent cancer cells from undergoing invasion and metastasis.CI - (c) 2011 The Authors. Journal compilation (c) 2011 by the Molecular Biology Society of Japan/Blackwell Publishing Ltd.

BACKGROUND: Pancreatic cancer is one of the most lethal cancers worldwide. The aim of this study was to determine the expression pattern, clinical significance, and biological functions of Wnt5a in pancreatic cancer. METHODS: Immunohistochemistry was performed to examine Wnt5a expression in 134 surgically resected pancreatic adenocarcinoma and adjacent normal pancreatic tissues. Associations of Wnt5a expression with clinicopathological factors and cancer-specific survival were analyzed. The effects of Wnt5a overexpression or silencing on the invasiveness and epithelial-to-mesenchymal transition (EMT) of pancreatic cancer cells were studied. Silencing of beta-catenin by small interfering RNA was done to determine its role in the Wnt5a-mediated tumor phenotype. RESULTS: The percentage of Wnt5a positive expression showed a bell-shaped pattern in pancreatic cancer tissues, peaking in well-differentiated carcinomas. The median cancer-specific survival was comparable between patients with positive versus negative expression of Wnt5a. Overexpression of Wnt5a promoted the migration and invasion of pancreatic cancer cells, whereas Wnt5a depletion had an inhibitory effect. In an orthotopic pancreatic cancer mouse model, Wnt5a overexpression resulted in increased invasiveness and metastasis, coupled with induction of EMT in tumor cells. Treatment with recombinant Wnt5a elevated the nuclear beta-catenin level in pancreatic cancer cells, without altering the Ror2 expression. Targeted reduction of beta-catenin antagonized exogenous Wnt5a-induced EMT and invasiveness in pancreatic cancer cells. CONCLUSION: Upregulation of Wnt5a promotes EMT and metastasis in pancreatic cancer models, which involves activation of beta-catenin-dependent canonical Wnt signaling. These findings warrant further investigation of the clinical relevance of Wnt5 upregulation in pancreatic cancer.

Colon cancer remains one of the lethal malignancies in the world. Aberrant activation of canonical Wnt/beta-catenin signaling pathway has been observed in colon cancer. In contrast, the non-canonical Wnt signaling functions remain obscure. Wnt5a is a representative non-canonical Wnt ligand which has gained extensive attention nowadays. Wnt5a has been shown to play an important role in EMT in prostate cancer and melanoma, but its role in colon cancer is still ambiguous. Here we have evaluated Wnt5a expression in a large cohort of 217 colon cancers by immunohistochemistry and analyzed its correlation with clinicopathologic characteristics. We found that expression of Wnt5a was diminished significantly in majority of primary colon cancers and negatively related with EMT biomarkers. To further enlighten the mechanism which Wnt5a regulates EMT in vitro, we established ectopic Wnt5a expression models. Protein analysis demonstrated that Wnt5a inhibited EMT and antagonized canonical Wnt signaling in colon cancer cells. Overexpression of Wnt5a impaired cell motility and invasion and inhibited cell proliferation by manipulating Bax. Moreover, Wnt5a suppressed the tumor growth in nude mice and impaired tumorigenicity in vivo. Wnt5a also induced intracellular calcium and activated non-canonical Wnt/Ca(2+) signaling in colon cancer. In summary, although Wnt5a was down-regulated in majority of colon cancers, enhanced Wnt5a expression predict preferable outcome in colon cancer patients. Our findings indicate that Wnt5a might act as tumor suppressor by inhibiting cell proliferation and attenuating EMT in colon cancer cells. Wnt5a could be used as a novel prognostic marker and/or therapeutic target for colon cancer in the future.CI - (c) 2014 Wiley Periodicals, Inc.

epithelial ovarian cancer is one of the most common causes of cancer-related death in women. The majority of epithelial ovarian cancer patients present with metastasis at the time of initial diagnosis. Studies have demonstrated that vasculogenic mimicry (VM) is highly correlated with metastasis and invasiveness, and epithelial-mesenchymal transition (EMT) is pivotal in VM formation. Wnt5a, a member of the Wnt protein family, can activate the non-canonical Wnt signaling pathway mediating cancer initiation and progression. Thus, the present study aimed to investigate the relationship between Wnt5a and VM and its mechanism in epithelial ovarian cancer. The present results showed that Wnt5a staining was significantly correlated with metastasis in epithelial ovarian cancer. The correlation between the expression of Wnt5a and VM or protein kinase Calpha (PKCalpha) indicated that Wnt5a was associated with VM and may be linked to the PKC pathway. In vitro experiments revealed that Wnt5a enhanced the vasculogenic capacity, motility and invasiveness of ovarian cancer cells; however, the PKCalpha inhibitor blocked these effects. Western blot analysis showed that changes in Wnt5a expression coincided with changes in PKC expression and that PI3K and Snail expression increased along with Wnt5a upregulation. However, no change was observed in beta-catenin levels, indicating that Wnt5a may mediate EMT and VM in ovarian cancer cells via the PKCalpha pathway.

The trans-spliced noncoding RNA RMST (tsRMST) is an emerging regulatory lncRNA in the human pluripotency circuit. Previously, we found that tsRMST represses lineage-specific transcription factors through the PRC2 complex and NANOG in human pluripotent stem cells (hESCs). Here, we demonstrate that tsRMST also modulates noncanonical Wnt signaling to suppress the epithelial-to-mesenchymal transition (EMT) and in vitro differentiation of embryonic stem cells (ESCs). Our results demonstrate that disruption of tsRMST expression in hESCs results in the upregulation of WNT5A, EMT, and lineage-specific genes/markers. Furthermore, we found that the PKC inhibitors Go6983 and Go6976 inhibited the effects of WNT5A, indicating that WNT5A promotes the EMT and in vitro differentiation although conventional and novel PKC activation in hESCs. Finally, we showed that either antiserum neutralization of WNT5A or Go6983 treatment in tsRMST knockdown cells decreased the expression of mesenchymal and lineage-specific markers. Together, these findings indicate that tsRMST regulates Wnt and EMT signaling pathways in hESCs by repressing WNT5A, which is a potential EMT inducer for promoting in vitro differentiation of hESCs through PKC activation. Our findings provide further insights into the role of trans-spliced RNA and WNT5A in hESC differentiation, in which EMT plays an important role. Stem Cells 2016;34:2052-2062.CI - (c) 2016 AlphaMed Press.

BACKGROUND: WNT5A (-/-) mammary tissue has been shown to exhibit increased ductal elongation, suggesting elevated mammary cell migration. Increased epithelial cell migration/invasion has often but not always been linked to the epithelial-mesenchymal transition (EMT). In the current study, we investigated the loss of WNT5A in HB2 human mammary epithelial cells and hypothesized that this loss increased their invasion via the EMT. Based on these results, we postulated that suppression of breast cancer cell migration and invasion by WNT5A is due to EMT reversal. METHODS: WNT5A was transiently knocked down using specific siRNAs, whereas WNT5A signaling was induced in MDA-MB468 and MDA-MB231 breast cancer cells by stably transfecting cells with WNT5A or treating them with recombinant WNT5A (rWNT5A). Changes in EMT markers, CD44, pAKT and AKT expression were assessed using Western blotting and immunofluorescence. The physiological relevance of altered WNT5A signaling was assessed using migration and invasion assays. RESULTS: WNT5A knockdown in HB2 mammary epithelial cells resulted in EMT-like changes and increased invasiveness, and these changes were partially reversed by the addition of rWNT5A. These data suggest that WNT5A might inhibit breast cancer cell migration and invasion by a similar EMT reversal. Contrary to our expectations, we did not observe any changes in the EMT status of breast cancer cells, either after treatment with rWNT5A or stable transfection with a WNT5A plasmid, despite the parallel WNT5A-induced inhibition of migration and invasion. Instead, we found that WNT5A signaling impaired CD44 expression and its downstream signaling via AKT. Moreover, knocking down CD44 in breast cancer cells using siRNA impaired cell migration and invasion. CONCLUSIONS: WNT5A bi-directionally regulates EMT in mammary epithelial cells, thereby affecting their migration and invasion. However, the ability of WNT5A to inhibit breast cancer cell migration and invasion is an EMT-independent mechanism that, at least in part, can be explained by decreased CD44 expression.

OBJECTIVES: We previously showed that DeltaNp63beta, a splicing variant of DeltaNp63, mediated EMT and affected cell motility. DNA microarray was thus performed to elucidate the mechanism that DeltaNp63beta affects cell motility. As the results, Wnt5a was significantly down-regulated by DeltaNp63beta overexpression in tongue SCC cell line (SQUU-B) with EMT phenotype. MATERIALS AND METHODS: Seven OSCC cell lines were used. expression of DeltaNp63, Wnt5a, its receptor Ror2, and matrix metalloproteinases (MMPs) were analyzed by RT-PCR, real-time PCR, and western blotting, and gelatin zymography. Furthermore, we examined the effects of siRNA for Wnt5a or Ror2 and recombinant human Wnt5a (rhWnt5a) on motility of tongue SCC cells. Biopsy specimens from tongue SCC patients were used for immunohistochemical staining of Wnt5a and Ror2. RESULTS: Wnt5a and Ror2 were expressed only in SQUU-B cells without DeltaNp63 expression, and negatively associated with DeltaNp63 expression in other cells. DeltaNp63beta overexpression in SQUU-B cells decreased Wnt5a and Ror2 expression. By Wnt5a or Ror2 knockdown, cell motility was remarkably inhibited, but EMT markers expression was unaffected. MMP-2 expression and the activities inversely correlated with DeltaNp63 expression, and were inhibited by Wnt5a or Ror2 knockdown. Cell motility and MMP-2 activities were recovered by adding rhWnt5a in the cells with Wnt5a knockdown, but not in those with Ror2 knockdown. Moreover, immunohistochemical analyses in tongue SCC specimens found that high expression of Wnt5a or Ror2 was associated with poorer prognosis. CONCLUSION: Wnt5a-Ror2 signaling enhanced tongue SCC cell aggressiveness and promoted production of MMP-2 following DeltaNp63beta-mediated EMT.CI - Copyright (c) 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

A recent study indicated that high Wnt5a expression is associated with poor prognosis in non-small-cell lung cancer (NSCLC) patients; however, the underlying mechanism was not clear yet. Immunohistochemistry and Western blotting were performed to examine the protein expression level in NSCLC tissues and cell lines. The role of Wnt5a in clone formation, invasiveness, migration, and epithelial-to-mesenchymal transition (EMT) of NSCLC cells was studied. Luciferase reporter assay was used to evaluate the Tcf/Lef transcriptional activity. For assessing the effects of Wnt5a on tumor growth and metastasis in vivo, A549 cells transfected with sh-Wnt5a were subcutaneously or orthotopically injected into nude mice. In NSCLC tissues, higher expression levels of Wnt5a and ROR2 were found, beta-Catenin was expressed exceptionally, and EMT was prompted. Wnt5a overexpression increased clone formation, migration, and invasion, as well as prompted EMT of NSCLC cell in vitro, whereas Wnt5a knockdown showed the absolutely reversed results. Wnt5a overexpression enhanced the Tcf/Lef transcriptional activity and elevated the nuclear beta-catenin level in NSCLC cells, without altering the ROR2 expression. We also demonstrated that si-beta-catenin antagonized Wnt5a overexpression nduced EMT and invasiveness. Besides, in vivo experiment showed that sh-Wnt5a significantly increased tumor volume and tumor weight, and prompted EMT in A549 tumor-bearing mice as compared with the control. No metastasis was found in the liver tissue after sh-Wnt5a-transfected cells were orthotopically injected into nude mice as compared with the control. In conclusion, Wnt5a promotes EMT and metastasis in NSCLC, which is involved in the activation of beta-catenin-dependent canonical Wnt signaling.CI - (c) 2017 The Author(s).

epithelial-mesenchymal transition (EMT) describes a process whereby polarized epithelial cells with restricted migration transform into elongated spindle-shaped mesenchymal cells with enhanced motility and invasiveness. Although there are some molecular markers for this process, including the down-regulation of E-cadherin, our understanding of plasma membrane (PM) and associated proteins involved in EMT is limited. To specifically explore molecular alterations occurring at the PM, we used the cationic colloidal silica isolation technique to purify PM fractions from epithelial Madin-Darby canine kidney cells during Ras/TGF-beta-mediated EMT. Proteins in the isolated membrane fractions were separated by one-dimensional SDS-PAGE and subjected to nano-LC-MS/MS-based protein identification. In this study, the first membrane protein analysis of an EMT model, we identified 805 proteins and determined their differential expression using label-free spectral counting. These data reveal that Madin-Darby canine kidney cells switch from cadherin-mediated to integrin-mediated adhesion following Ras/TGF-beta-mediated EMT. Thus, during the EMT process, E-cadherin, claudin 4, desmoplakin, desmoglein-2, and junctional adhesion molecule A were down-regulated, whereas integrins alpha6beta1, alpha3beta1, alpha2beta1, alpha5beta1, alphaVbeta1, and alphaVbeta3 along with their extracellular ligands collagens I and V and fibronectin had increased expression levels. Conspicuously, Wnt-5a expression was elevated in cells undergoing EMT, and transient Wnt-5a siRNA silencing attenuated both cell migration and invasion in these cells. Furthermore, Wnt-5a expression suppressed canonical Wnt signaling induced by Wnt-3a. Wnt-5a may act through the planar cell polarity pathway of the non-canonical Wnt signaling pathway as several of the components and modulators (Wnt-5a, -5b, frizzled 6, collagen triple helix repeat-containing protein 1, tyrosine-protein kinase 7, RhoA, Rac, and JNK) were found to be up-regulated during Ras/TGF-beta-mediated EMT.

Activation of Wnt5a-Ror2 signaling has been shown to be associated with epithelial-to-mesenchymal transition (EMT) of epidermoid carcinoma cells via induction of matrix metalloproteinase-2 (MMP-2). Because EMT has also been implicated in the progression of tissue fibrosis, we examined the possible association of Wnt5a-Ror2 signaling with renal fibrosis. Here, we show that expression of Wnt5a and Ror2 is induced in a damaged mouse kidney after unilateral ureteral obstruction (UUO) treatment. Immunofluorescent analysis showed that Ror2 expression is clearly induced in tubular epithelial cells during renal fibrosis, and these Ror2-expressing cells also express Snail and vimentin, markers of mesenchymal cells, suggesting that Ror2 might be induced in epithelial cells undergoing EMT. We also found that MMP-2 expression is induced at Ror2-positive epithelium adjacent to significantly disrupted tubular basement membrane (TBM). Interestingly, reduced expression of MMP-2 is detected at epithelium in damaged kidneys from Ror2(+/-) mice compared with those from wild-type Ror2(+/+) mice. Importantly, extents of TBM disruption are apparently reduced in damaged kidneys from Ror2(+/-) mice compared with those from wild-type mice. Collectively, these findings indicate that activation of Wnt5a-Ror2 signaling in epithelial cells undergoing EMT may play an important role in disrupting TBM via MMP-2 induction during renal fibrosis.CI - (c) 2013 The Authors Genes to Cells (c) 2013 by the Molecular Biology Society of Japan and Wiley Publishing Asia Pty Ltd.