Increased E-cadherin mRNA Research Articles

The flavonoid quercetin reduces cell migration and increases NIS and E-cadherin mRNA in the human thyroid cancer cell line BCPAP

Thyroid cancer is the most frequent cancer of the endocrine system. Most patients are treated with thyroidectomy followed by radioiodine therapy. However, in part of the patients, a reduction of the sodium-iodide symporter (NIS) occurs, rendering radioiodine therapy ineffective. Moreover, epithelial–mesenchymal transition (EMT) may occur, leading to more aggressive and invasive features. Herein, we evaluated the effect of the flavonoid quercetin on EMT and NIS expression in BCPAP, a papillary thyroid carcinoma cell line. BCPAP was treated with 100 μM quercetin for 24 h and cell viability, apoptosis, EMT markers and NIS were evaluated. Quercetin decreased cell viability by enhancing apoptosis. The flavonoid also reduced matrix metalloproteinase 9 and increased E-cadherin mRNA levels, inhibiting BCPAP adhesion and migration. Additionally, quercetin increased NIS expression and function. Thus, our results suggest that quercetin could be useful as adjuvant in thyroid cancer therapy, inducing apoptosis, reducing invasion and increasing the efficacy of radioiodine therapy.

MiR-200b attenuates IL-6 production through IKK\u03b2 and ZEB1 in human gingival fibroblasts

ObjectiveMicroRNAs (miRNAs) play important roles in biological processes such as cell differentiation, development, infection, immune response, inflammation and tumorigenesis. We previously reported that the expression of miR-200b was significantly increased in inflamed gingiva compared with non-inflamed gingiva. To elucidate the roles of miR-200b in the inflamed gingiva, we have analyzed the effects of miR-200b on the expression of IL-6 in human gingival fibroblasts (HGF).Materials and methodsTotal RNA and protein were extracted from HGF after stimulation by interleukin-1β (IL-1β; 1 ng/ml) or tumor necrosis factor-α (TNF-α; 10 ng/ml) and transfected with miR-200b expression plasmid or miR-200b inhibitor. IL-6, IL-1β, inhibitor of nuclear factor kappa-B kinaseβ (IKKβ), Zinc-finger E-box-binding homeobox 1 (ZEB1) and E-cadherin mRNA and protein levels were analyzed by real-time PCR and Western blot.ResultsIL-1β and TNF-α increased IL-6 mRNA and protein levels, and they were significantly suppressed by miR-200b overexpression, whereas they were further increased by miR-200b inhibitor in HGF. IKKβ and ZEB1 which are target genes of miR-200b negatively regulate E-cadherin. MiR-200b suppressed the expression of IKKβ and ZEB1 and increased E-cadherin mRNA and protein levels in HGF.ConclusionsThese results suggest that miR-200b attenuates inflammatory response via IKKβ and ZEB1 in periodontal tissue.

BHX, a novel pyrazoline derivative, inhibits breast cancer cell invasion by reversing the epithelial-mesenchymal transition and down-regulating Wnt/\u03b2-catenin signalling

The novel pyrazoline derivative, BHX, has recently been shown to exhibit potent anti-tumour activity by blocking the Wnt/β-catenin signalling pathway. However, its effect on breast cancer growth and invasion are unknown. Our results show that BHX suppresses MDA-MB-231 cell viability and colony formation in a dose-dependent manner, and induces apoptosis and G0/G1 phase arrest. BHX-treated breast cancer cells showed morphological characteristics of cells undergoing apoptosis. Furthermore, BHX inhibited cell migration and invasion, which was associated with increased E-cadherin mRNA and protein expression, and down-regulation of SNAIL and vimentin. In addition, BHX induced the generation of intracellular ROS and decreased β-catenin protein and mRNA expression. We used a mouse xenograft model to investigate the effects of BHX in vivo, where the growth of MDA-MB-231 xenografted tumours was suppressed in nude mice treated continuously with BHX for 21 days. Finally, the rat plasma concentration of BHX was measured by ultra-performance liquid-chromatography tandem mass spectrometry and the pharmacokinetic parameters of BHX were processed by non-compartmental analysis. In conclusion, BHX merits further study as a novel therapeutic small molecule for the treatment of breast cancer.

CCL22 and IL-37 inhibit the proliferation and epithelial-mesenchymal transition process of NSCLC A549 cells.

In the present study, we aimed to investigate the effects of CC chemokine ligand 22 (CCL22) and interleukin-37 (IL-37) on the proliferation and epithelial-mesenchymal transition (EMT) of non-small cell lung cancer (NSCLC) A549 cells. pDsRed-CCL22 and pEGFP-IL-37 plasmids were constructed. A549 cells were divided into six groups: the control, the pDsRed-N1 blank plasmid, the pEGFP-C1 blank plasmid, the pDsRed-CCL22 plasmid, the pEGFP‑IL-37 plasmid and the pDsRed-CCL22+pEGFP-IL-37 plasmid group. Expression levels and localization of CCL22 and IL-37 in cells were detected by confocal microscopy. Phase-contrast microscopy was applied for observing cellular morphology. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used for detecting the mRNA levels of vimentin, N-cadherin and E-cadherin, and their protein expression levels were tested using western blotting. Constructed plasmids expressed CCL22 and IL-37, both of which had a co-localization in the cell membrane. MTT assay and cell observation results revealed that CCL22 and IL-37 inhibited the proliferation and EMT process of the A549 cells. The results of RT-qPCR and western blotting revealed that decreased vimentin and N-cadherin mRNA and protein expression levels, and increased E-cadherin mRNA and protein expression levels were found in the pDsRed-CCL22 plasmid, pEGFP-IL-37 plasmid and pDsRed‑CCL22+pEGFP‑IL-37 plasmid groups when compared with the control, the pDsRed-N1 blank plasmid and the pEGFP-C1 blank plasmid groups (all P<0.05), and decreased vimentin and N-cadherin mRNA and protein expression levels and increased E-cadherin mRNA and protein expression levels were found in the pDsRed‑CCL22+pEGFP‑IL-37 plasmid group when compared with the pDsRed-CCL22 plasmid and the pEGFP‑IL-37 plasmid groups (all P<0.05). CCL22 and IL-37 with a co-localization in the A549 cells inhibited the proliferation and EMT process in A549 cells. The antitumor effects of CCL22 and IL37 provide a strategy for the treatment of NSCLC.

Abstract 521: Connexin 43 and E-cadherin modulate prostate cancer cell migration

Abstract Connexins play a major role in cell-cell communication and form a bidirectional signaling pathway to assemble gap junctions and, along with cadherins, alter cell behaviors, such as motility. To assess the effect of Connexin 43 (Cx43) on migration of prostate cancer cells we performed two types of migration assays using shRNA Cx43 transfected PC3 cells with suppressed Cx 43. Wound healing and transwell chamber assays were used to assess the migratory potential of stably transfected shCx43-PC3 cells. When we reduced Cx 43 we saw approximately a two-fold reduction in migration of shCx43 transfected PC3 cells compared to those transfected with scramble controls. Since suppression of Cx43 reduced migration of the highly migratory PC3 cells, we wondered whether this reflected a partial loss of mesenchymal traits (e.g., motility) and acquisition of epithelial markers, (e.g.,E-cadherin expression). Using quantitative RT-PCR, E-cadherin expression was assessed in shCx43-PC3 and scramble control cells. Suppression of Cx43 increased E-cadherin mRNA levels 5-fold or greater in shCx43-PC3 cells than in scramble control cells. An alternative approach used to transcriptionally up-regulate E-cadherin mRNA in PC3 cells (via suppression of a transcriptional repressor) resulted in a similar approximately 2.5-fold suppression of migration as measured by wound healing and transwell chamber assays. Thus, an inverse relation of Cx 43 and E-cadherin was observed in prostate cancer cells and alterations in either led to aberrant migration. These results were consistent with our hypothesis that differential connexin expression in prostate cancer cells contributes to different metastatic potential. To correlate differential connexin subunit expression with migratory potential, we quantified gene expression of 13 different Connexin subunits in non-invasive LNCaP and in invasive PC3 cells using qRTPCR. In LNCaP cells we observed low levels of Cx43 along with high levels of Cx32 and E-cadherin expression and the converse in PC3 cells. Overall, these results suggest that reducing high levels of Cx43, associated with enhanced E-cadherin expression and reduced migratory behavior could potentially block lethal metastatic tumor progression of prostate cancer cells. Citation Format: Abdulaziz Aloliqi, Ao Zhang, Adina Brett-Morris, Justin Lathia, Gail C. Fraizer. Connexin 43 and E-cadherin modulate prostate cancer cell migration. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 521. doi:10.1158/1538-7445.AM2015-521

HIF1α deficiency reduces inflammation in a mouse model of proximal colon cancer.

ABSTRACTHypoxia-inducible factor 1α (HIF1α) is a transcription factor that regulates the adaptation of cells to hypoxic microenvironments, for example inside solid tumours. Stabilisation of HIF1α can also occur in normoxic conditions in inflamed tissue or as a result of inactivating mutations in negative regulators of HIF1α. Aberrant overexpression of HIF1α in many different cancers has led to intensive efforts to develop HIF1α-targeted therapies. However, the role of HIF1α is still poorly understood in chronic inflammation that predisposes the colon to carcinogenesis. We have previously reported that the transcription of HIF1α is upregulated and that the protein is stabilised in inflammatory lesions that are caused by the non-steroidal anti-inflammatory drug (NSAID) sulindac in the mouse proximal colon. Here, we exploited this side effect of long-term sulindac administration to analyse the role of HIF1α in colon inflammation using mice with a Villin-Cre-induced deletion of Hif1α exon 2 in the intestinal epithelium (Hif1αΔIEC). We also analysed the effect of sulindac sulfide on the aryl hydrocarbon receptor (AHR) pathway in vitro in colon cancer cells. Most sulindac-treated mice developed visible lesions, resembling the appearance of flat adenomas in the human colon, surrounded by macroscopically normal mucosa. Hif1αΔIEC mice still developed lesions but they were smaller than in the Hif1α-floxed siblings (Hif1αF/F). Microscopically, Hif1αΔIEC mice had significantly less severe colon inflammation than Hif1αF/F mice. Molecular analysis showed reduced MIF expression and increased E-cadherin mRNA expression in the colon of sulindac-treated Hif1αΔIEC mice. However, immunohistochemistry analysis revealed a defect of E-cadherin protein expression in sulindac-treated Hif1αΔIEC mice. Sulindac sulfide treatment in vitro upregulated Hif1α, c-JUN and IL8 expression through the AHR pathway. Taken together, HIF1α expression augments inflammation in the proximal colon of sulindac-treated mice, and AHR activation by sulindac might lead to the reduction of E-cadherin protein levels through the mitogen-activated protein kinase (MAPK) pathway.

Molecular Mechanisms Involved in the Synergistic Interaction of the EZH2 Inhibitor 3-Deazaneplanocin A with Gemcitabine in Pancreatic Cancer Cells

Pancreatic ductal adenocarcinoma (PDAC) is characterized by overexpression of enhancer of Zeste homolog-2 (EZH2), which plays a pivotal role in cancer stem cell (CSC) self-renewal through methylation of histone H3 lysine-27 (H3K27me3). Against this background, EZH2 was identified as an attractive target, and we investigated the interaction of the EZH2 inhibitor DZNeP with gemcitabine. EZH2 expression was detected by quantitative PCR in 15 PDAC cells, including seven primary cell cultures, showing that expression values correlated with their originator tumors (Spearman R(2) = 0.89, P = 0.01). EZH2 expression in cancer cells was significantly higher than in normal ductal pancreatic cells and fibroblasts. The 3-deazaneplanocin A (DZNeP; 5 μmol/L, 72-hour exposure) modulated EZH2 and H3K27me3 protein expression and synergistically enhanced the antiproliferative activity of gemcitabine, with combination index values of 0.2 (PANC-1), 0.3 (MIA-PaCa-2), and 0.7 (LPC006). The drug combination reduced the percentages of cells in G(2)-M phase (e.g., from 27% to 19% in PANC-1, P < 0.05) and significantly increased apoptosis compared with gemcitabine alone. Moreover, DZNeP enhanced the mRNA and protein expression of the nucleoside transporters hENT1/hCNT1, possibly because of the significant reduction of deoxynucleotide content (e.g., 25% reduction of deoxycytidine nucleotides in PANC-1), as detected by liquid chromatography/tandem mass spectrometry. DZNeP decreased cell migration, which was additionally reduced by DZNeP/gemcitabine combination (-20% in LPC006, after 8-hour exposure, P < 0.05) and associated with increased E-cadherin mRNA and protein expression. Furthermore, DZNeP and DZNeP/gemcitabine combination significantly reduced the volume of PDAC spheroids growing in CSC-selective medium and decreased the proportion of CD133+ cells. All these molecular mechanisms underlying the synergism of DZNeP/gemcitabine combination support further studies on this novel therapeutic approach for treatment of PDACs.

Synthetic (glyco-)peptides of the homophilic recognition domain of E-cadherin lead to increased E-cadherin mRNA synthesis and are inductors of cell differentiation in primary lung cancer cell lines

E-cadherin is one of the critical molecules involved in the metastatic process in many types of cancer. Once combined, E-cadherin exceeds the amount of membranous E-cadherin on the cellular surface by activation of intracellular signaling cascades. Studies on transformed keratinocytes of the HaCat cell line showed induction of differentiation by synthetical partial structures of the homophilic binding region of E-cadherin. The knowledge of effects in lung cancer cells is sparse. Therefore, the effects in primary lung cancer cell lines were investigated. Four primary lung cancer cell lines were incubated for 3, 6, 12, 15, 18, and 24 h with synthetic partial structures (peptide and glycopeptide). The control substance was sodium butyrate. mRNA was isolated, and relative quantification of E-cadherin was performed using the Real-Time PCR. During the stimulation period, morphologic pictures were taken, and immunohistochemical staining of membranous E-cadherin was performed. Life/dead assays were used to display cell vitality. The intracellular E-cadherin mRNA amount was increased after incubation with the synthetic partial structures. Life/dead assays showed improved survival and integrated cell/cell bindings after stimulation with the partial structures. Increased cell mortality was revealed after sodium butyrate incubation. An effect mediated via E-cadherin on the cellular surface is proposed. The two synthetic partial structures of the homophilic binding region of E-cadherin increased the intracellular E-cadherin mRNA amount, cell–cell bindings, and survival of the tumor cells. Extracellular binding by synthetic partial structures to the binding region may have a beneficial influence on tumor progression in the metastatic process.

Abstract 5650: Silibinin inhibits epithelial to mesenchymal transition in prostate cancer cells: Role of E-cadherin and beyond

Abstract Prostate cancer (PCA) is second leading cause of cancer-related deaths in US men. High morbidity and mortality in PCA patients are due to its metastatic spread to distant organs. Epithelial to mesenchymal transition (EMT) in PCA cells is considered a pre-requisite for acquiring advanced migratory/invasive phenotype, and for subsequent metastasis. Even though multiple signaling mechanisms and cellular changes are involved in EMT, loss of E-cadherin is considered as the single most important biological event in PCA cells for acquiring an invasive mesenchymal phenotype. Accordingly, we hypothesized that promoting E-cadherin expression in PCA cells using non-toxic phytochemicals, such as silibinin, would prevent EMT and subsequent metastasis. Recently, we have established strong efficacy of silibinin against PCA cells and currently it is in phase II clinical trial in PCA patients, but its efficacy and mechanism against EMT in PCA cells are largely unknown. Results of present study showed that silibinin strongly inhibits migratory potential of quiescent PC3 and PC3MM2 PCA cells in wound healing assay (P less than 0.001); and invasive potential of PC3 (by 11-66%), PC3MM2 (by 11-61%) and C4-2B (by 32-71%) cells in transwell matrigel invasion assay. Importantly, cell viability assay confirmed that anti-invasive effect of silibinin was not due to its cytotoxicity. Immunoblot analysis showed that silibinin increases E-cadherin expression in PC3 cells in a dose and time dependent manner, which was at cellular membrane as evidenced by sub-cellular fractional and confocal analyses. Silibinin treatment also decreased the level of transcriptional repressors (Snail1, Slug and ZEB1) and increased E-cadherin mRNA expression. Silibinin treatment also decreased the level of phosphorylated Src and Hakai (an E-3 ubiquitin ligase) suggesting post-translational stabilization of E-cadherin. In other studies, silibinin decreased nuclear and cytoplasmic level of beta-catenin but not in cellular membrane. Morphological examination supported these molecular alterations as silibinin treated PC3 cells were more adherent. Similar E-cadherin increase, beta-catenin decrease and morphological changes with silibinin were also observed in PC3MM2 and C4-2B cells. Next, we generated PC3 cells with stable knock-down of E-cadherin expression (ShEC-PC3) and respective control cells (Sh-PC3). Employing these cells, we found that the anti-migratory/anti-invasive potential of silibinin is only partially dependent on E-cadherin. Since molecules, other than E-cadherin, affected by silibinin treatment (beta-catenin, Snail1, Slug and ZEB1) could also directly influence EMT-related changes, our findings suggest multiple molecular targets of silibinin in its anti-EMT and anti-migratory/anti-invasive potential. Overall, the results of present study suggest silibinin usefulness against PCA metastasis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5650.

E-Cadherin Expression Is Regulated by miR-192/215 by a Mechanism That Is Independent of the Profibrotic Effects of Transforming Growth Factor-β

OBJECTIVEIncreased deposition of extracellular matrix (ECM) within the kidney is driven by profibrotic mediators including transforming growth factor-β (TGF-β) and connective tissue growth factor (CTGF). We investigated whether some of their effects may be mediated through changes in expression of certain microRNAs (miRNAs).RESEARCH DESIGN AND METHODSProximal tubular cells, primary rat mesangial cells, and human podocytes were analyzed for changes in the expression of key genes, ECM proteins, and miRNA after exposure to TGF-β (1–10 ng/μl). Tubular cells were also infected with CTGF-adenovirus. Kidneys from diabetic apoE mice were also analyzed for changes in gene expression and miRNA levels.RESULTSTGF-β treatment was associated with morphologic and phenotypic changes typical of epithelial-mesenchymal transition (EMT) including increased fibrogenesis in all renal cell types and decreased E-cadherin expression in tubular cells. TGF-β treatment also modulated the expression of certain miRNAs, including decreased expression of miR-192/215 in tubular cells, mesangial cells, which are also decreased in diabetic kidney. Ectopic expression of miR-192/215 increased E-cadherin levels via repressed translation of ZEB2 mRNA, in the presence and absence of TGF-β, as demonstrated by a ZEB2 3′-untranslated region luciferase reporter assay. However, ectopic expression of miR-192/215 did not affect the expression of matrix proteins or their induction by TGF-β. In contrast, CTGF increased miR-192/215 levels, causing a decrease in ZEB2, and consequently increased E-cadherin mRNA.CONCLUSIONSThese data demonstrate the linking role of miRNA-192/215 and ZEB2 in TGF-β/CTGF–mediated changes in E-cadherin expression. These changes appear to occur independently of augmentation of matrix protein synthesis, suggesting that a multistep EMT program is not necessary for fibrogenesis to occur.

Fibroblast Growth Factor 2 Reactivates G1 Checkpoint in SK-N-MC Cells via Regulation of p21, Inhibitor of Differentiation Genes (Id1-3), and Epithelium-Mesenchyme Transition-Like Events

We have recently demonstrated that fibroblast growth factor (FGF)-2 promotes neuroblastoma cell differentiation and overrides their mitogenic response to IGF-I. However, the mechanisms involved are unknown. SK-N-MC cells were cultured with FGF-2 (50 ng/ml) and/or IGF-I (100 ng/ml) up to 48 h. Fluorescence-activated cell sorting analysis indicated that FGF-2 promotes G1/G0 cell cycle phase arrest. Gene expression by RT2-PCR and cellular localization showed up-regulation of p21. We then investigated whether FGF-2-induced differentiation of SK-N-MC cells (by GAP43 and NeuroD-6 expression) involves epithelium-mesenchyme transition interconversion. Real-time PCR (RT2-PCR) showed modulation of genes involved in maintenance of the epithelial phenotype and cell-matrix interactions (E-cadherin, Snail-1, MMPs). Zymography confirmed FGF-2 up-regulated MMP2 and induced MMP9, known to contribute to neuronal differentiation and neurite extension. Id1-3 expression was determined by RT2-PCR. FGF-2 induced Id2, while down-regulating Id1 and Id3. FGF-2 induced nuclear accumulation of ID2 protein, while ID1 and ID3 remained cytoplasmic. RNA interference demonstrated that Id3 regulates differentiation and cell cycle (increased Neuro-D6 and p21 mRNA), while d Id2 modulates epithelium-mesenchyme transition-like events (increased E-cadherin mRNA). In conclusion, we have shown for the first time that FGF-2 induces differentiation of neuroblastoma cells via activation of a complex gene expression program enabling modulation of cell cycle, transcription factors, and suppression of the cancer phenotype. The use of RNA interference indicated that Id-3 is a key regulator of these events, thus pointing to a novel therapeutic target for this devastating childhood cancer.

Cyclooxygenase‐2 and RhoA Signaling Disrupts Cell‐Cell Adhesion by the Regulation of the Transcriptional Repressor, ZEB‐1

Cyclooxygenase 2 (COX‐2) plays a critical role in colon cancer and loss of the adhesion molecule E‐cadherin is one of the hallmarks that indicate a tumor cell has become invasive. The aim for this study is to investigate if the transcription repressor ZEB1 is a crucial component linking COX‐2 and RhoA/ROCK signaling to down‐regulation of E‐cadherin. In the cells lines that expressed COX‐2 , activity of RhoA was elevated, and formation adherens junctions were disrupted, which was concomitant with down‐regulation of E‐cadherin. In contrast, inhibition of COX‐2, inactivation of RhoA by expressing dominant negative RhoA or inhibition of ROCK, restored E‐cadherin levels in the same COX‐2 expressing cells. Quantitative real‐time RT‐PCR showed that E‐cadherin was down‐regulated at transcriptional level in cells expressing COX‐2. Furthermore, both protein and mRNA levels of ZEB1 were highly elevated in cells expressing COX‐2. We also found that expression of constitutively active RhoA resulted in increased ZEB1 and decreased E‐cadherin expression, which were prevented when ROCK was inhibited. Importantly, silencing ZEB1 expression in cells expressing COX‐2 markedly increased E‐cadherin mRNA and protein levels. Thus, our results showed for the first time that the RhoA/ROCK pathway mediates COX‐2 signaling to increase ZEB1 expression, which is required to modulate E‐cadherin and formation of adherens junctions.

Polyamines regulate E-cadherin transcription through c-Myc modulating intestinal epithelial barrier function

The integrity of the intestinal epithelial barrier depends on intercellular junctions that are highly regulated by numerous extracellular and intracellular factors. E-cadherin is found primarily at the adherens junctions in the intestinal mucosa and mediates strong cell-cell contacts that have a functional role in forming and regulating the epithelial barrier. Polyamines are necessary for E-cadherin expression, but the exact mechanism underlying polyamines remains elusive. The current study was performed to determine whether polyamines induce E-cadherin expression through the transcription factor c-Myc and whether polyamine-regulated E-cadherin plays a role in maintenance of the epithelial barrier integrity. Decreasing cellular polyamines reduced c-Myc and repressed E-cadherin transcription as indicated by a decrease in levels of E-cadherin promoter activity and its mRNA. Forced expression of the c-myc gene by infection with adenoviral vector containing c-Myc cDNA stimulated E-cadherin promoter activity and increased E-cadherin mRNA and protein levels in polyamine-deficient cells. Experiments using different E-cadherin promoter mutants revealed that induction of E-cadherin transcription by c-Myc was mediated through the E-Pal box located at the proximal region of the E-cadherin promoter. Decreased levels of E-cadherin in polyamine-deficient cells marginally increased basal levels of paracellular permeability but, remarkably, potentiated H(2)O(2)-induced epithelial barrier dysfunction. E-cadherin silencing by transfection with its specific small interfering RNA also increased vulnerability of the epithelial barrier to H(2)O(2). These results indicate that polyamines enhance E-cadherin transcription by activating c-Myc, thus promoting function of the epithelial barrier.

Increased E-cadherin expression in the ligated kidney following unilateral ureteric obstruction

E-cadherin expression in the kidney is used as a surrogate marker of epithelial mesenchymal transition for the testing of various antifibrotic strategies. Here we reexamined E-cadherin expression in the kidneys of rats with unilateral ureteric obstruction, which was previously reported to decrease in parallel with the development of tubulointerstitial disease in this widely used experimental model of renal fibrosis and epithelial mesenchymal transition. E-cadherin mRNA expression was consistently increased both acutely (hours) and chronically (days) in the ligated kidney compared to the cognate non-ligated kidney. Increased E-cadherin protein levels were also found in the ligated kidney particularly in dilated tubular segments. Simulation of early pressure changes in the ligated kidney by mechanical stretch of human renal epithelial cells in culture did not alter E-cadherin expression. Porcine LLCPK-1 cells subjected to hypotonic stretch, however, did have increased E-cadherin mRNA and protein levels, responses that were not prevented by transforming growth factor-beta, a cytokine that promotes epithelial mesenchymal transition. Our findings question the utility of E-cadherin as a marker of epithelial mesenchymal transition in this model of renal fibrosis.