Expression Of EMT-related Markers Research Articles

Expression of epithelial-mesenchymal transition-related markers in triple-negative breast cancer: ZEB1 as a potential biomarker for poor clinical outcome.

Triple-negative breast cancer (TNBC) is a heterogeneous group of disease with a well-known association with epithelial-mesenchymal transition (EMT) and breast cancer stem cell phenotype. Recent studies have shown that TNBC can be classified into 6 subtypes, including basal-like, mesenchymal-like, and mesenchymal stem-like subtypes. However, clinical significance of the EMT in TNBC remains unclear. We analyzed immunohistochemical expression of EMT-related markers, including EMT markers (expression of vimentin, smooth muscle actin, osteonectin, and N-cadherin; loss of E-cadherin), EMT inducers (ZEB1 and CD146), and breast cancer stem cell markers (CD44(+)/CD24(-) and aldehyde dehydrogenase 1) in 173 TNBCs and correlated their expression with clinicopathological features of the tumors, including clinical outcome. Expressions of vimentin, CD44(+)/CD24(-), and CD146 were more frequent in basal-like TNBCs than non-basal-like TNBCs. Whereas CD146 expression was closely associated with the expression of various EMT markers and CD44(+)/CD24(-) phenotype, ZEB1 expression correlated only with the expression of smooth muscle actin. Expressions of vimentin, smooth muscle actin, osteonectin, and ZEB1 and loss of E-cadherin were more frequently found in metaplastic carcinomas than in other histologic subtypes. In survival analyses, EMT markers were not associated with patients' clinical outcomes. However, ZEB1 expression was found to be an independent prognostic factor for poor disease-free survival. These findings indicate that expression of EMT-related markers in TNBCs can be a signature of a certain subgroup of TNBC, which is associated with metaplastic carcinoma, and ZEB1 expression can serve as a potential biomarker to define a subgroup of TNBC associated with poor clinical outcomes.

Short hairpin RNA- mediated gene knockdown of FOXM1 inhibits the proliferation and metastasis of human colon cancer cells through reversal of epithelial-to-mesenchymal transformation.

BackgroundThe Forkhead box M1 (FOXM1) is an oncogenic transcription factor and plays a significant role in cell EMT, proliferation, metastasis in a multitude of human solid tumors including colorectal cancer (CRC). However, the underlying molecular mechanisms by which FoxM1 contributes to epithelial-to-mesenchymal (EMT) and metastasis have not been fully elucidated in CRC.MethodsIn our study, we investigated FOXM1 protein expression in 87 CRC tissue specimens, invasive lymph nodes and adjacent paired normal colorectal tissues by immunohistochemical analysis. Then we transfected FOXM1 specific shRNA into SW620 cells to examine effect of FOXM1 on proliferation, colony formation, migration and invasion in vitro. Western blotting and real-time PCR were used to detect the protein and mRNA expression of FOXM1 and EMT-related markers.ResultsFOXM1 was overexpressed in CRC tissues, invasive lymph nodes and CRC cell lines. FoxM1 overexpression was significantly associated with lymph node metastasis (P < 0.001), and tumor recurrence (P < 0.001). Moreover, downregulation of FOXM1 in SW620 cells by shRNA approach inhibited cell growth, clonogenicity, migration and invasion in vitro. In addition, decreased FOXM1 expression in SW620 cells reversed the acquisition of EMT phenotype by up-regulating E-cadherin, as well as reduction Vimentin and Snail expressions at protein and mRNA levels.ConclusionsFOXM1 may regulate CRC cells metastasis through EMT program and FOXM1 may be a potential target for treatment of CRC.

S100 Calcium-Binding Protein A6 Promotes Epithelial-Mesenchymal Transition through β-Catenin in Pancreatic Cancer Cell Line

The pathogenesis of pancreatic ductal adenocarcinoma (PDAC) remains poorly understood. S100 calcium-binding protein A6 (S100A6) has been associated with PDAC; however, the effect of S100A6 on PDAC migration and invasion has not yet been explored. In this study, Panc-1 cells were transfected with a plasmid to induce overexpression of S100A6, and β-catenin was knocked down using a specific short hairpin RNA (shRNA). The wound-healing and Transwell assays demonstrated that S100A6 promoted PDAC cell migration and invasion. Furthermore, β-catenin shRNA inhibited the migration and invasion of PDAC cells. We confirmed that S100A6 induces PDAC cell migration and invasion via activation of β-catenin in vitro. Assessment of mRNA and protein levels revealed that S100A6 induces increased expression of β-catenin, N-cadherin and vimentin, and decreased expression of E-cadherin in PDAC cells. β-catenin shRNA also altered the expression of epithelial-mesenchymal transition (EMT)-related markers in PDAC cells. Specifically, expression of E-cadherin was increased, whereas expression of N-cadherin and vimentin was decreased. Finally, we demonstrated that S100A6 alters the expression of EMT-related markers via β-catenin activation. In conclusion, S100A6 induces EMT and promotes cell migration and invasion in a β-catenin-dependent manner. S100A6 may therefore represent a novel potential therapeutic target for the treatment of pancreatic cancer.

Helicobacter pylori Might Induce TGF-β1-Mediated EMT by Means of cagE.

Epithelial-mesenchymal transition (EMT), in which polarized epithelial cells have mesenchymal cell phenotypes, is thought to be a key process of invasion and metastasis of cancer. Transforming growth factor beta-1 (TGF-β1) is known to be carcinogenic and Helicobacter pylori is a predominant carcinogen of gastric cancer. Our study aimed to determine whether TGF-β1 or H. pylori infection enhances EMT process and cytotoxin-associated gene E (CagE) is associated with EMT. Human gastric cancer cell AGS and MKN45 were treated with recombinant TGF-β1 or H. pylori including cagE-negative (ΔcagE) mutant. Besides the assessment of EMT-related markers expression levels by means of RT-qPCR, Western blot, and immunofluorescence assay, the induction of in vitro EMT on gastric cancer cells (AGS and MKN cell lines) was confirmed by wound-healing assay and invasion assay. When gastric cancer cells were treated with TGF-β1 or various strains of cagE-positive H. pylori, EMT-related marker altered significantly. However, the ΔcagE mutant did not. Wound-healing assay and invasion assay showed enhanced migration ability of the cells treated with cagE-positive H. pylori but not in ΔcagE mutant. EMT induction in gastric cancer cells by TGF-β1 was confirmed. Only infection with cagE-positive H. pylori upregulated the TGF-β1-mediated EMT pathway and consequently promotes EMT. Therefore, H. pylori might induce TGF-β1-mediated EMT associated with the cagE.

FAK activation is required for IGF1R-mediated regulation of EMT, migration, and invasion in mesenchymal triple negative breast cancer cells.

Triple negative breast cancer (TNBC) is a highly metastatic disease that currently lacks effective prevention and treatment strategies. The insulin-like growth factor 1 receptor (IGF1R) and focal adhesion kinase (FAK) signaling pathways function in numerous developmental processes, and alterations in both are linked with a number of common pathological diseases. Overexpression of IGF1R and FAK are closely associated with metastatic breast tumors. The present study investigated the interrelationship between IGF1R and FAK signaling in regulating the malignant properties of TNBC cells. Using small hairpin RNA (shRNA)-mediated IGF1R silencing methods, we showed that IGF1R is essential for sustaining mesenchymal morphologies of TNBC cells and modulates the expression of EMT-related markers. We further showed that IGF1R overexpression promotes migratory and invasive behaviors of TNBC cell lines. Most importantly, IGF1R-driven migration and invasion is predominantly mediated by FAK activation and can be suppressed using pharmacological inhibitors of FAK. Our findings in TNBC cells demonstrate a novel role of the IGF1R/FAK signaling pathway in regulating critical processes involved in the metastatic cascade. These results may improve the current understanding of the basic molecular mechanisms of TNBC metastasis and provide a strong rationale for co-targeting of IGF1R and FAK as therapy for mesenchymal TNBCs.

Abstract 1059: EGF induces epithelial-mesenchymal transition and cancer stem cell properties in human oral squamous cell carcinoma

Abstract Head and neck cancer is one of the 10 most common cancers worldwide. Despite advances in therapeutic research in the last few decades, morbidity and mortality remain unchanged. Recurrent and metastatic oral squamous cell carcinoma (OSCC) of the head and neck may have correlated with epithelial-mesenchymal transition (EMT), a property acquired by cancer stem cells (CSCs). In our study, SCC-1 cells (a human tongue cancer cell line) treated with epidermal growth factor (EGF) underwent EMT as confirmed by morphological changes and expression of EMT-related markers using Western blot, immunocytostaining, and flow cytometric analyses. Our data showed that, in comparison with non-treated cells, EGF treatment induced SCC-1 cells to undergo EMT, characterized by spindle-shaped mesenchymal-like morphology, an altered suppression of E-cadherin and promotion of vimentin expression, and an enhanced invasive capacity. Our results also indicated that EGF significantly enriched the fraction of CD44+/CD24low/- CSCs in SCC-1 cells, from 7∼8% to 25∼29%, and simultaneously increased the expression of aldehyde dehydrogenase 1 (ALDH1), a common marker for stem cells. Moreover, the purified CD44+/CD24low/- CSC population displayed stem cell properties associated with EMT phenotypes and increased migration and invasion abilities in vitro. Using a murine orthotopic tongue cancer model transplanted with stably GFP-expressing SCC-1 cells (GFP-SCC-1), we confirmed that EGF can promote tumor metastasis to cervical lymph nodes, and simultaneously augmented CD44 and ALDH1 expression in these invasive tumor cells. Taken together, we have demonstrated that EGF-induced EMT process is closely associated with the acquisition of CSC properties in human OSCC, which may contribute to the increased distant metastasis and recurrence of head and neck cancer. Further elucidation of the underlying mechanisms will facilitate development of new generation of effective therapies that aim to specifically target CSCs and eliminate the “root” of cancer recurrence. This work was supported by National Institute of Health Research Grant, R01DE 019932, Oral and Maxillofacial Surgery Foundation Research Support, 002894, and the Schoenleber funding support. Citation Format: Qilin Xu, Qunzhou Zhang, Anh Le. EGF induces epithelial-mesenchymal transition and cancer stem cell properties in human oral squamous cell carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1059. doi:10.1158/1538-7445.AM2014-1059

Upregulation of autophagy by hypoxia-inducible factor-1α promotes EMT and metastatic ability of CD133+ pancreatic cancer stem-like cells during intermittent hypoxia.

Epithelial-to-mesenchymal transition (EMT) facilitates the escape of pancreatic cancer cells from the primary tumor site, which is a key early event in metastasis. In the present study, we examined if intermittent hypoxia facilitates the invasiveness of human pancreatic cancer cell lines (Panc-1 and BxPC-3) by Transwell assay. We used western blotting and flow cytometry analysis to quantify stem-like cells in the migratory cells during intermittent hypoxia in the human pancreatic cancer cells. Under normoxia or intermittent hypoxia, the expression of autophagy-related proteins (LC3-II and Beclin), hypoxia-inducible factor-1α (HIF-1α) and EMT-related markers (E-cadherin, Vimentin and N-cadherin) was examined by western blotting. siRNA and the autophagic inhibitor were used to access the role of HIF-1α and autophagy in promoting metastasis and EMT. Under intermittent hypoxia, pancreatic cancer cells demonstrated enhanced invasive ability and enriched stem-like cells. The migratory cells displayed stem-like cell characteristics and elevated the expression of LC3-II and Beclin-1, HIF-1α, E-cadherin, Vimentin and N-cadherin under intermittent hypoxia conditions. Moreover, enhanced autophagy was induced by the elevated level of HIF-1α. The metastatic ability and EMT of pancreatic cancer stem cells was associated with HIF-1α and autophagy. This novel finding may indicate the specific role of HIF-1α and autophagy in promoting the metastatic ability of pancreatic cancer stem cells. Additionally, it emphasizes the importance of developing therapeutic strategies targeting cancer stem cells and autophagy to reduce metastasis.

MiR-429 inhibits cells growth and invasion and regulates EMT-related marker genes by targeting Onecut2 in colorectal carcinoma.

The 5-year survival rate for colorectal cancer is approximately 55 % because of its invasion and metastasis. The epithelial–mesenchymal transition (EMT) is one of the well-defined processes during the invasion and distant metastasis of primary epithelial tumors. miR-429, a member of the miR-200 family of microRNAs, was previously shown to inhibit the expression of transcriptional repressors ZEB1/delta EF1 and SIP1/ZEB2, and regulate EMT. In this study, we showed that miR-429 was significantly downregulated in colorectal carcinoma (CRC) tissues and cell lines. We found that miR-429 inhibited the proliferation and growth of CRC cells in vitro and in vivo, suggesting that miR-429 could play a role in CRC tumorigenesis. We also showed that downregulation of miR-429 may contribute to carcinogenesis and the initiation of EMT of CRC by targeting Onecut2. Further researches indicated that miR-429 inhibited the cells migration and invasion and reversed TGF-β-induced EMT changes in SW620 and SW480 cells. miR-429 could reverse the change of EMT-related markers genes induced by TGF-β1, such as E-cadherin, CTNNA1, CTNNB1, TFN, CD44, MMP2, Vimentin, Slug, Snail, and ZEB2 by targeting Onecut2. Taken together, our data showed that transcript factor Onecut2 is involved in the EMT, migration and invasion of CRC cells; miR-429 inhibits the initiation of EMT and regulated expression of EMT-related markers by targeting Onecut2; and miR-429 or Onecut2 is the important therapy target for CRC. Electronic supplementary materialThe online version of this article (doi:10.1007/s11010-013-1950-x) contains supplementary material, which is available to authorized users.

Mesenchymal phenotype after chemotherapy is associated with chemoresistance and poor clinical outcome in esophageal cancer

The relationship between the epithelial-mesenchymal transition (EMT) and resistance to anticancer treatment has attracted attention in recent years. However, to date, there is no direct clinical evidence for a link between the mesenchymal phenotype and chemoresistance in human malignancies. The expression of EMT-related markers, including E-cadherin, Snail, vimentin, ZEB1, β-catenin and N-cadherin was examined immunohistochemically in 185 tissue samples from patients with esophageal cancer (including 93 patients who received preoperative chemotherapy followed by surgery and 92 patients who underwent surgery without preoperative therapy). The relationship between the expression of the above markers and clinical outcome including prognosis and response to chemotherapy was also examined. The expression of E-cadherin, a marker of epithelial cells, was significantly lower in residual tumors than chemo-naive tumors (P=0.003). The expression of Snail (P=0.028), ZEB1 (P<0.001) and N-cadherin (P=0.001), markers of mesenchymal cells, was higher in residual tumors than in chemonaive tumors. The expression of E-cadherin correlated inversely with that of Snail (P<0.001). Reduced expression of E-cadherin and increased expression of Snail in residual tumors from patients who received chemotherapy correlated significantly with poor response to chemotherapy and short survival time. Multivariate analysis identified Snail expression as an independent prognostic factor, along with tumor depth, in patients who received preoperative chemotherapy for esophageal cancer. The results suggest transition of residual esophageal cancer cells to mesenchymal phenotype after chemotherapy and this contributes to resistance to chemotherapy and poor prognosis in patients with esophageal cancer.

Heterogeneity of Mesenchymal Markers Expression—Molecular Profiles of Cancer Cells Disseminated by Lymphatic and Hematogenous Routes in Breast Cancer

Breast cancers can metastasize via hematogenous and lymphatic routes, however in some patients only one type of metastases are detected, suggesting a certain proclivity in metastatic patterns. Since epithelial-mesenchymal transition (EMT) plays an important role in cancer dissemination it would be worthwhile to find if a specific profile of EMT gene expression exists that is related to either lymphatic or hematogenous dissemination. Our study aimed at evaluating gene expression profile of EMT-related markers in primary tumors (PT) and correlated them with the pattern of metastatic spread. From 99 early breast cancer patients peripheral blood samples (N = 99), matched PT (N = 47) and lymph node metastases (LNM; N = 22) were collected. Expression of TWIST1, SNAI1, SNAI2 and VIM was analyzed in those samples. Additionally expression of CK19, MGB1 and HER2 was measured in CTCs-enriched blood fractions (CTCs-EBF). Results were correlated with each other and with clinico-pathological data of the patients. Results show that the mesenchymal phenotype of CTCs-EBF correlated with poor clinico-pathological characteristics of the patients. Additionally, PT shared more similarities with LNM than with CTCs-EBF. Nevertheless, LNM showed increased expression of EMT-related markers than PT; and EMT itself in PT did not seem to be necessary for lymphatic dissemination.

EMT markers in lung adenocarcinoma pleural effusion spheroid cells

Epithelial-to-mesenchymal transition (EMT) is a process in which cells undergo a developmental switch from epithelial to mesenchymal phenotype. This process has been related to embryologic morphogenesis but also to cancer progression and metastasis. The aim of the current study was to investigate the expression of EMT-related markers in adherent and spheroid cell cultures derived from malignant pleural effusions (MPEs) of patients affected by lung adenocarcinoma. On the basis of efficient in vitro propagation, six cases of MPEs were selected and analyzed by immunocytochemistry staining for EMT markers and by RT-PCR for transcription factors known to orchestrate EMT. EMT markers immunostaining showed in spheroids a statistically significant correlation between the loss of E-cadherin immunoreactivity and overexpression of N-cadherin (P < 0.001). Likewise loss of EpCAM epithelial marker was coincident with Vimentin overexpression (P < 0.001). RT-PCR analysis of transcription factors Snail, Slug, and Twist showed a highly variable expression, although a general trend to increase was observed. Importantly, in some selected cases it was possible to establish a precise relationship between spheroid formation, EMT switch and increased upregulation of the marker related to cancer stemness such as ALDH positivity. Therefore, MPE-derived cell cultures, while recapitulating the heterogeneity of lung cancer, are a suitable system to study the mechanisms at the basis of EMT and to understand its relationship with the generation of cancer stem cells.

TACC3 promotes epithelial–mesenchymal transition (EMT) through the activation of PI3K/Akt and ERK signaling pathways

Transforming acidic coiled-coil protein 3 (TACC3) is a member of the TACC family, essential for mitotic spindle dynamics and centrosome integrity during mitosis. Mounting evidence suggests that deregulation of TACC3 is associated with various types of human cancer. However, the molecular mechanisms by which TACC3 contributes to the development of cancer remain largely unknown. Here, we propose a novel mechanism by which TACC3 regulates epithelial–mesenchymal transition (EMT). By modulating the expression of TACC3, we found that overexpression of TACC3 leads to changes in cell morphology, proliferation, transforming capability, migratory/invasive behavior as well as the expression of EMT-related markers. Moreover, phosphatidylinositol 3-kinase (PI3K)/Akt and extracellular signal-regulated protein kinases (ERKs) signaling pathways are critical for TACC3-mediated EMT process. Notably, depletion of TACC3 is sufficient to suppress EMT phenotype. Collectively, our findings identify TACC3 as a driver of tumorigenesis as well as an inducer of oncogenic EMT and highlight its overexpression as a potential therapeutic target for preventing EMT-associated tumor progression and invasion.

Abstract P5-04-03: Epithelial-mesenchymal transition is associated with in situ to invasive transition of basal-like breast cancer

Abstract BACKGROUND: Epithelial-mesenchymal transition (EMT) is known to play an important role in breast cancer invasion and metastatic progression and to be associated with cancer stem cells and basal-like subtype. However, its role in the progression of in situ to invasive breast carcinoma is uncertain. To investigate this question, we evaluated the difference in the expression of EMT-related markers between pure ductal carcinoma in situ (DCIS) and invasive carcinomas according to molecular subtype. METHODS: We performed immunohistochemical analyses of EMT-related markers [expression of vimentin, smooth muscle actin (SMA), osteonectin and N-cadherin, translocation of β-catenin and loss of E-cadherin] and breast cancer stem cell markers (CD44+/CD24−, ALDH1) in 320 invasive carcinomas and 179 pure DCIS of breast using tissue microarrays. We also analyzed 39 basal-like invasive cancers with adjacent DCIS component to determine the difference in the expression of EMT-related markers in the invasive and DICS component within individual cases. RESULTS: In invasive carcinomas, vimentin, SMA and osteonectin were highly expressed in basal-like subtype. In addition, loss of E-cadherin and translocation of β-catenin were most frequently found in basal-like subtype. Furthermore, there were positive correlations between the expression of EMT-related markers and stem cell markers (CD44+/CD24- and ALDH1). However, there was no significant difference in the expression of EMT-related markers according to molecular subtype in pure DCIS. When comparing invasive carcinoma with pure DCIS, expression of EMT-related markers was significantly higher in invasive carcinoma than in pure DCIS. Subgroup analysis revealed higher expression of EMT-related markers in invasive carcinoma than in DCIS in basal-like subtype, but not in non-basal-like subtypes. Moreover, in 39 basal-like invasive cancers with adjacent DCIS, expression of mesenchymal markers was increased in invasive component compared to DCIS component. CONCLUSIONS: Our study confirmed that EMT is an intrinsic characteristic of basal-like subtype and is associated with breast cancer with stem cell phenotype. However, increased expression of EMT-related markers in invasive carcinoma compared to pure DCIS, especially in basal-like subtype, and in the invasive component of basal-like invasive carcinoma with DCIS component also suggests a role of EMT in the transition of in situ- to invasive carcinoma in basal-like breast cancer. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-04-03.

Endoplasmic reticulum protein 29 regulates epithelial cell integrity during the mesenchymal–epithelial transition in breast cancer cells

The epithelial-mesenchymal transition (EMT) correlates with disruption of cell-cell adhesion, loss of cell polarity and development of epithelial cell malignancy. Identifying novel molecules that inhibit EMT has profound potential for developing mechanism-based therapeutics. We previously demonstrated that the endoplasmic reticulum protein 29 (ERp29) is a novel factor that can drive mesenchymal-epithelial transition (MET) and induce cell growth arrest in MDA-MB-231 cells. Here, we show that ERp29 is an important molecule in establishing epithelial cell integrity during the MET. We demonstrate that ERp29 regulates MET in a cell context-dependent manner. ERp29 overexpression induced a complete MET in mesenchymal MDA-MB-231 cells through downregulating the expression of transcriptional repressors (for example, Slug, Snai1, ZEB2 and Twist) of E-cadherin. In contrast, overexpression of ERp29 induces incomplete MET in basal-like BT549 cells in which the expression of EMT-related markers (for example, vimentin; cytokeratin 19 (CK19) and E-cadherin) and the transcriptional repressors of E-cadherin were not altered. However, ERp29 overexpression in both cell-types resulted in loss of filamentous stress fibers, formation of cortical actin and restoration of an epithelial phenotype. Mechanistic studies revealed that overexpression of ERp29 in both cell-types upregulated the expression of TJ proteins (zonula-occludens-1 (ZO-1) and occludin) and the core apical-basal polarity proteins (Par3 and Scribble) at the membrane to enhance cell-cell contact and cell polarization. Knockdown of ERp29 in the epithelial MCF-7 cells decreased the expression of these proteins, leading to the disruption of cell-cell adhesion. Taken together, ERp29 is a novel molecule that regulates MET and epithelial cell integrity in breast cancer cells.

Epithelial mesenchymal transition correlates with CD24+CD44+ and CD133+ cells in pancreatic cancer

The epithelial-mesenchymal transition (EMT) has been linked to induction of a stem-cell like phenotype, characterized by altered cell surface marker expression and increased tumor formation. The aim of this study was to investigate whether EMT correlates with CD24+CD44+ and CD133+ cells in pancreatic cancer. The morphology of untreated and gemcitabine-treated SW1990 gemcitabine-resistant cells and normal SW1990 cells were compared. NF-κB p65 expression was knocked down using siRNA. Vimentin and E-cadherin expression were analyzed using western blotting, and CD24+CD44+, CD133+ cells were quantified by FACS. Additionally, immunohistochemistry of EMT-associated markers and stem cell-associated markers were performed in 41 cases of human pancreatic ductal adenocarcinoma. In SW1990 gemcitabine-resistant cells, gemcitabine induced a mesenchymal cell phenotype, expression of EMT-related molecular markers and increased CD24+CD44+ and CD133+ cells compared to untreated SW1990 gemcitabine-resistant and SW1990 cells. Knockdown of NF-κB p65 inhibited the ability of gemcitabine to increase the proportion of CD24+CD44+ or CD133+ cells and expression of EMT-related molecular markers. In human pancreatic ductal adenocarcinoma, significant correlations were observed between expression of the EMT-associated markers vimentin and E-cadherin, and stem cell-associated markers CD24, CD133 and CD44. This study demonstrated that EMT correlated with CD24+CD44+ and CD133+ cells in pancreatic cancer. This study also suggests that EMT may induce cancer stem-like cells in pancreatic cancer, with different degrees of EMT probability inducing different proportions of CD24+CD44+ and CD133+ cells.

Metadherin enhances the invasiveness of breast cancer cells by inducing epithelial to mesenchymal transition

The epithelial-mesenchymal transition (EMT) is a process in which polarized epithelial cells are converted into motile mesenchymal cells. During cancer development, EMT is conducive to tumor dissemination and metastatic spread. While overexpression of metadherin (MTDH) in breast cancer cell lines and tissues has been found to be associated with aggressive tumor behavior, its precise role in invasion and metastasis is largely unknown. Here we report that MTDH overexpression could significantly enhance the invasion and migration of breast cancer cells by inducing EMT. Metadherin overexpression led to upregulation of mesenchymal marker fibronectin, downregulation of epithelial marker E-cadherin, and the nuclear accumulation of beta-catenin. Also, transcription factors Snail and Slug were upregulated in breast cancer cells overexpressing MTDH. Overexpression of MTDH enhanced the invasiveness and migration ability of breast cancer cells in vitro. In addition, overexpression of MTDH led to increased acquisition of CD44(+) /CD24(-/low) markers that are characteristic of breast cancer stem cells. We also showed that NF-kappa was involved in the expression of EMT-related markers. Taken together, our results suggest that MTDH could promote EMT in breast cancer cells in driving the progression of their aggressive behavior.

Simultaneous Stimulation with TGF-β1 and TNF-α Induces Epithelial Mesenchymal Transition in Bronchial Epithelial Cells

Background: Airway remodeling is an important feature of chronic airway disease, but the mechanisms involved remain unclear. Recently, epithelial mesenchymal transition (EMT) was reported to be associated with tissue fibrosis. TGF-β1, which is a potent inducer of EMT, is thought to be related to the pathogenesis of airway remodeling. We investigated whether TGF-β1 and/or TNF-α induce EMT in bronchial epithelial cells. Methods: Cultured BEAS-2B cells and primary normal human bronchial epithelial cells (NHBE) were treated with TGF-β1 and/or TNF-α. Morphological changes and the expression of EMT-related markers were evaluated by immunocytochemical staining. Expressions of EMT-related markers, extracellular matrix (ECM) components (collagen type I and versican), and TGF-β receptors I, II, and III were analyzed by quantitative RT-PCR. Migration was evaluated using the Boyden chamber technique. Results: The TGF-β1-induced EMT in BEAS-2B cells was demonstrated on the basis of morphological changes and the downregulation of E-cadherin. Costimulation with TNF-α enhanced the TGF-β1-induced morphological changes and increased vimentin expression. Treatment with TGF-β1 increased the expression of collagen type I and versican. EMT induced with TGF-β1 plus TNF-α promoted cell migration. Stimulation of NHBE with TGF-β1 led to EMT. Conclusion: TGF-β1 induced EMT in BEAS-2B cells, and costimulation with TNF-α enhanced the EMT. As a result of the EMT process, BEAS-2B cells acquired functions of mesenchymal cells. In addition, TGF-β1 treatment induced EMT in NHBE as shown by changes in EMT-related markers. Bronchial epithelial cells might contribute to airway remodeling through EMT.