Expression Pattern Of E-cadherin Research Articles

Claudin-1 induces epithelial–mesenchymal transition through activation of the c-Abl-ERK signaling pathway in human liver cells

Claudins (CLDNs) are a family of integral membrane proteins central to the formation of tight junctions, structures that are involved in paracellular transport and cellular growth and differentiation, and are critical for the maintenance of cellular polarity. Recent studies have provided evidence that CLDNs are aberrantly expressed in diverse types of human cancers, including hepatocellular carcinomas (HCCs). However, little is known about how CLDN expression is involved in cancer progression. In this study, we show that CLDN1 has a causal role in the epithelial-mesenchymal transition (EMT) in human liver cells, and that the c-Abl-Ras-Raf-1-ERK1/2 signaling axis is critical for the induction of malignant progression by CLDN1. Overexpression of CLDN1 induced expression of the EMT-regulating transcription factors Slug and Zeb1, and thereby led to repression of E-cadherin, β-catenin expression, enhanced expression of N-cadherin and Vimentin, a loss of cell adhesion, and increased cell motility in normal liver cells and HCC cells. In line with these findings, inhibition of either c-Abl or ERK clearly attenuated CLDN1-induced EMT, as evidenced by a reversal of N-cadherin and E-cadherin expression patterns, and restored normal motility. Collectively, these results indicate that CLDN1 is necessary for the induction of EMT in human liver cells, and that activation of the c-Abl-Ras-Raf-1-ERK1/2 signaling pathway is required for CLDN1-induced acquisition of the malignant phenotype. The present observations suggest that CLDN1 could be exploited as a biomarker for liver cancer metastasis and might provide a pivotal point for therapeutic intervention in HCC.

E-cadherin in canine mast cell tumors: Decreased expression and altered subcellular localization in Grade 3 tumors

Mast cell tumors (MCTs) are the most frequent round cell tumors in dogs and comprise approximately 21% of all canine cutaneous tumors. MCTs are highly invasive and metastatic corresponding to the histological grade. E-cadherin is an adhesion molecule expressed in epithelial cells and although it is an epithelial cellular marker, studies have shown expression of E-cadherin in canine round cell tumors. To better characterize the expression pattern of E-cadherin in several different histological grades of MCTs in dogs, the expression and localization of the adhesion molecule was investigated using immunohistochemistry. For this purpose, 18 cutaneous MCTs were classified into three histological grades, 1, 2 or 3. Clinical history and follow-up data were available for all of the dogs. Cytoplasmic and nuclear expressions of E-cadherin in all three types of tumors were verified by immunostaining using two different antibodies. There was decreased E-cadherin expression in the more aggressive MCTs (Grade 3), suggesting an association between E-cadherin and tumor aggressiveness. Additionally, the loss of E-cadherin expression in either the cytoplasm or nucleus in more aggressive and undifferentiated tumor types confirmed the importance of cellular adhesion in tumor behavior.

Overexpression of ETV4 is oncogenic in prostate cells through promotion of both cell proliferation and epithelial to mesenchymal transition

The discovery of translocations that involve one of the genes of the ETS family (ERG, ETV1, ETV4 and ETV5) has been a major advance in understanding the molecular basis of prostate cancer (PC). Each one of these translocations results in deregulated expression of one of the ETS proteins. Here, we focus on the mechanism whereby overexpression of the ETV4 gene mediates oncogenesis in the prostate. By siRNA technology, we show that ETV4 inhibition in the PC3 cancer cell line reduces not only cell mobility and anchorage-independent growth, but also cell proliferation, cell cycle progression and tumor growth in a xenograft model. Conversely, ETV4 overexpression in the nonmalignant human prostate cell line (RWPE) increases anchorage-independent growth, cell mobility and cell proliferation, which is probably mediated by downregulation of p21, producing accelerated progression through the cell cycle. ETV4 overexpression is associated with changes in the pattern of E-cadherin and N-cadherin expression; the cells also become spindle-shaped, and these changes are characteristic of the so-called epithelial to mesenchymal transition (EMT). In RWPE cells overexpressing ETV4 EMT results from a marked increase in EMT-specific transcription factors such as TWIST1, SLUG1, ZEB1 and ZEB2. Thus, whereas ETV4 shares with the other ETS proteins (ERG, ETV5 and ETV1) a major role in invasiveness and cell migration, it emerges as unique in that it increases at the same time also the rate of proliferation of PC cells. Considering the wide spectrum in the clinical course of patients with PC, it may be highly relevant that ETV4 is capable of inducing most and perhaps all of the features that make a tumor aggressive.

Immunophenotypes of Glycogen Rich Clear Cell Carcinoma

PurposeGlycogen rich clear cell carcinoma (GRCC) of the breast is a rare subtype of invasive ductal carcinoma and involves a poor prognosis. In the literature, less than 150 cases have been reported. Many researchers have attempted to characterize GRCC according to electron microscope, flow cytometry, or clinical data. However, an organized study of the immunophenotype of GRCC has yet to be reported.Materials and MethodsHere, we present three cases of GRCC and their immunohistochemical profiles.ResultsHistologically, all three cases contained periodic acid stain (PAS) positive and d-PAS labile granules in their clear cytoplasm. Case I showed positivity for only estrogen receptor (ER) and c-erbB2. Case II exhibited positivity for progesterone receptor and negativity for ER and c-erbB2. Case III presented with triple negative invasive carcinoma. The expression pattern of E-cadherin was concordant with epidermal growth factor receptor and c-kit, but discordant with ki-67. Among these three cases, p53-positive cases exhibited a low proliferative index (ki-67: 15%), while p53-negative cases showed a high proliferative index (ki-67: 50-60%).ConclusionIn conclusion, the immunophenotype of GRCC is not uniform, but is similar to that of conventional ductal carcinoma.

Prostaglandin E(2) and interleukin-1β reduce E-cadherin expression by enhancing snail expression in gastric cancer cells.

Inflammation is closely related to the progression of cancer as well as tumorigenesis. Here, we investigated the effect of prostaglandin E2 (PGE2) and interleukin-1β (IL-1β) on E-cadherin expression in SNU719 gastric cancer cells. E-cadherin expression decreased as the dose or exposure time of PGE2 and IL-1β increased, whereas Snail expression increased with dose or time of PGE2 and IL-1β. E-cadherin expression reduced by PGE2 treatment increased after the transfection of Snail siRNA. Neutralization of IL-1β using anti-IL-1β antibody blocked the expression pattern of E-cadherin and Snail occurred by IL-1β treatment. However, there was no synergic effect of IL-1β and PGE2 on the expression pattern of E-cadherin and Snail. In conclusion, inflammatory mediators reduced E-cadherin expression by enhancing Snail expression in gastric cancer cells. Inflammation-induced transcriptional regulation of E-cadherin in gastric cancer has implications for targeted chemoprevention and therapy.

Comparison Study of E-cadherin Expression in Primary Breast Cancer and its Corresponding Metastatic Lymph Node

Introduction: E-cadherin is an intercellular adhesion molecule, whose loss of expression may facilitate the process of cancer invasion and metastasis. Although the expression of E-cadherin has been widely studied in primary breast cancers, little is known about its expression at the corresponding metastatic lymph node. Here we comparatively studied their E-cadherin expression patterns and related them to the pathological data of breast cancer patients. Methods: Only lymph nodes which were pathologically identified as metastases were included in this study to pair up the primary tumors. The quantitative real-time PCR (Q-RT-PCR) technique was used to assess the Ecadherin RNA expression levels in invasive ductal breast cancer subjects. E-cadherin gene copies were normalized using beta-actin gene copies. ER, PR, cerbB2 expressions in the primary tumor were routinely examined by immunohistochemistry method. Tumor characteristics and number of metastatic lymph nodes were gathered from the pathology reports. Results: We tried to explore the relationship between E-cadherin expression in 21 primary tumors and their corresponding metastatic lymph nodes. However, the Q-RT-PCR data shows that an aberrant expression exists in both primary tumors and the corresponding lymph nodes (p=0.115), in which metastatic lymph nodes showed slight higher gene copies comparing to primary sites (77.77 ± 94.74vs43.35 ± 40.03, respectively). It is noteworthy that nodal E-cadherin expression was closely but negatively correlated with tumor size (p 0.05). Conclusions: These study shows that E-cadherin expression is aberrant in invasive ductal cancers and their corresponding metastatic lymph nodes. E-cadherin expression in the metastasized lymph node is closely related to tumor size and number of metastasized lymph nodes.

Association of E-cadherin single nucleotide polymorphisms with the increased risk of endometriosis in Indian women

The objective of the present study was to investigate the association between gene E-cadherin single nucleotide polymorphisms (SNPs) and risk of developing endometriosis in Indian women and to evaluate the role of E-cadherin expression in the pathophysiology of endometriosis. A genetic association study was conducted in 715 endometriosis cases and 500 controls of Indian origin. We genotyped -160 C/A, +54 C/T and -347 G/GA SNPs of gene E-cadherin by PCR-sequencing and PCR-restriction fragment length polymorphism techniques. Haplotype frequencies for multiple loci and the standardized disequilibrium coefficient (D') for pair-wise linkage disequilibrium (LD) were assessed by Haploview Software. In addition, to better understand genetic contributions to the pathophysiology of endometriosis, the expression pattern of E-cadherin in the endometrium of women with and without endometriosis was analyzed by western blot and immunohistochemical analysis. The frequencies of -347GA/GA (P = 0.026) and -160A/A (P = 0.0019) genotypes and -347G/-160A/+54C (P = 0.007) and -347GA/-160A/+54C (P < 0.0001) haplotypes were significantly different between patients and controls. Strong LD was observed between -347G/GA and -160C/A loci (D' = 0.64) when compared with -347G/GA and +54C/T (D' = 0.585) or -160C/A and +54C/T (D' = 0.05) loci in cases. Furthermore, increased membranous E-cadherin expression was observed in cases than in controls. The expression seems to be genotype dependent. In conclusion, the E-cadherin -347GA/GA and -160A/A genotypes and -347GA/-160A/+54C and -347G/-160A/+54C haplotypes may jointly modify the risk of endometriosis in Indian women. In addition, the differential expression of E-cadherin may play an important role in pathogenesis of endometriosis.

Investigation of β-catenin and E-cadherin Expression in Dukes B2 Stage Colorectal Cancer with Tissue Microarray Method. Is It a Marker of Metastatic Potential in Rectal Cancer?

β-catenin and E cadherin are both membrane-associated proteins which are essential regulators and providers of cellular adhesion. In the metastatic cascade of malignant tumours, detachment of tumour cells from each other is a very important step. It has been shown in several tumour types, that reduced expression of these proteins is important. The aim of our study was to clarify the expression profile of these proteins, and correlate the findings with the metastasizing potential of early stage colon and rectal cancers. Formalin fixed and paraffin embedded samples from 79 Dukes B2 stage colorectal cancer were examined using a tissue microarray approach. The expression of β-catenin and E-cadherin proteins was determined immunohistochemically. Our findings indicated that there is a tendency for metastatic spread in cases when membranous expression of β-catenin is lost (p = 0.062). Similarly metastases in negative cases developed more rapidly, than in positive ones (p = 0.05). Survival rate was worse in the negative cases. The risk of metastasis in rectal cancer was significantly higher in the β-catenin membranously negative than positive groups (p = 0.024) and in case of β-catenin nuclear expression the risk was also higher (p = 0.047). Reduced E-cadherin expression also correlated with development of metastatic disease, but this association was statistically not significant. The immunohistochemical analysis of 79 cases shows that in Dukes B2 stage colorectal tumours clarification of β-catenin and E-cadherin expression patterns is reliable for predicting the metastatic potential of early stage rectal cancer and hence the method may have relevant implications in the therapeutic management of these cancers.

Mutant p53 Disrupts MCF-10A Cell Polarity in Three-dimensional Culture via Epithelial-to-mesenchymal Transitions

Mutant p53 is not only deficient in tumor suppression but also acquires additional activity, called gain of function. Mutant p53 gain of function is recapitulated in knock-in mice that carry one null allele and one mutant allele of the p53 gene. These knock-in mice develop aggressive tumors compared with p53-null mice. Recently, we and others showed that tumor cells carrying a mutant p53 are addicted to the mutant for cell survival and resistance to DNA damage. To further define mutant p53 gain of function, we used the MCF-10A three-dimensional model of mammary morphogenesis. MCF-10A cells in three-dimensional culture undergo a series of morphological changes and form polarized and growth-arrested spheroids with hollow lumen, which resembles normal glandular architectures in vivo. Here, we found that endogenous wild-type p53 in MCF-10A cells was not required for acinus formation, but knockdown of endogenous wild-type p53 (p53-KD) led to partial clearance of cells in the lumen due to decreased apoptosis. Consistent with this, p53-KD altered expression patterns of the cell adhesion molecule E-cadherin, the cytoskeletal marker β-catenin, and the extracellular matrix protein laminin V. We also found that ectopic expression of the mutant G245S led to a phenotype similar to p53-KD, whereas a combination of ectopic expression of siRNA-resistant G245S with p53-KD led to a less cleared lumen. In contrast, ectopic expression of mutant R248W, R175H, and R273H disrupted normal acinus architectures with filled lumen and led to formation of irregular and multiacinus structures regardless of p53-KD. In addition, these mutants altered normal expression patterns and/or levels of E-cadherin, β-catenin, laminin V, and tight junction marker ZO-1. Furthermore, epithelial-to-mesenchymal transitions (EMT) markers, Snail, Slug, and Twist, were highly induced by mutant p53 and/or p53-KD. Together, we postulate that EMT represents a mutant p53 gain of function and mutant p53 alters cell polarity via EMT.

359 EXPRESSION PROFILE OF E-CADHERIN AND N-CADHERIN IN UROTHELIAL CARCINOMA OF THE UPPER URINARY TRACT AS A NOVEL PREDICTOR OF RECURRENCE FOLLOWING NEPHROURETERECTOMY

You have accessJournal of UrologyUrothelial Cancer: Markers + Natural History & Pathophysiology1 Apr 2011359 EXPRESSION PROFILE OF E-CADHERIN AND N-CADHERIN IN UROTHELIAL CARCINOMA OF THE UPPER URINARY TRACT AS A NOVEL PREDICTOR OF RECURRENCE FOLLOWING NEPHROURETERECTOMY Mototsugu Muramaki, Hideaki Miyake, Sadao Kamidono, and Masato Fujisawa Mototsugu MuramakiMototsugu Muramaki Kobe, Japan More articles by this author , Hideaki MiyakeHideaki Miyake Kobe, Japan More articles by this author , Sadao KamidonoSadao Kamidono Kobe, Japan More articles by this author , and Masato FujisawaMasato Fujisawa Kobe, Japan More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.445AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES In normal tissues, epithelial and mesenchymal cells mainly express E-cadherin and N-cadherin, respectively; however, several recent studies have demonstrate the important role of a switch from E-cadherin to N-cadherin in cancer cells, which is regarded as one aspect of the epithelial-to-mesenhymal transition, in the malignant progression through their enhanced mortility and invasive potential. The objective of this study was to investigate the impact of the expression patterns of E-cadherin and N-cadherin on the probability of intra- and extra-vesical recurrence of urothelial carcinoma of the upper urinary treact (UC-UUT) following nephroureterectomy. METHODS Expression levels of E-cadherin and N-cadherin were evaluated by immunohistochemical staining in a consecutive series of 59 UC-UUT specimens from patients undergoing nephroureterectomy. Intra- and extra-vesical recurrence-free survival rates were calculated using the Kaplan-Meier method. Various predictive factors for postoperative recurrence were evaluated using multivariate analysis. RESULTS Median follow-up period of the 59 patients was 32 months (range, 12 – 79 months). Among these 59 patients, intra- and extra-vesical recurrence occurred in 20 (33.9%) and 19 (32.2%) patients, respectively. Low E-cadherin expression was associated with extravesical recurrence but not intravesical recurrence (p = 0.006), while high N-cadherin expression was associated with both intra- and extra-vesical recurrence (p = 0.026 and 0.017, respectively). When high risk group was defined as patients with low expression level of E-cadherin and high expression level of N-cadherin, 18 of the 59 patients (30.5%) were classified in this group. Of these 18, 12 (66.7%) and 15 (83.3%) patients developed postoperative intra- and extra-vesical recurrence, respectively. Furthermore, classification of high risk group appeared to be an independent predictive factor for both intra- and extra-vesical recurrence following nephroureterectomy (p = 0.015 and 0.002, respectively) on the multivariate analysis. CONCLUSIONS These findings suggest that reduced expression of E-cadherin and increased expression of N-cadherin is a powerful predictive factor for postoperative intra- and extra-vesical recurrence of UC-UUT, suggesting the important role of a switch from E-cadherin to N-cadherin expression in the recurrence of UC-UUT. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e146 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Mototsugu Muramaki Kobe, Japan More articles by this author Hideaki Miyake Kobe, Japan More articles by this author Sadao Kamidono Kobe, Japan More articles by this author Masato Fujisawa Kobe, Japan More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Epithelial-to-mesenchymal transition in cyst lining epithelial cells in an orthologous PCK rat model of autosomal-recessive polycystic kidney disease

In polycystic kidney disease (PKD), cyst lining cells show polarity abnormalities. Recent studies have demonstrated loss of cell contact in cyst cells, suggesting induction of epithelial-to-mesenchymal transition (EMT). Recently, EMT has been implicated in the pathogenesis of PKD. To explore further evidence of EMT in PKD, we examined age- and segment-specific expression of adhesion molecules and mesenchymal markers in PCK rats, an orthologous model of human autosomal-recessive PKD. Kidneys from 5 male PCK and 5 control rats each at 0 days, 1, 3, 10, and 14 wk, and 4 mo of age were serially sectioned and stained with segment-specific markers and antibodies against E-cadherin, Snail1, β-catenin, and N-cadherin. mRNAs for E-cadherin and Snail1 were quantified by real-time PCR. Vimentin, fibronectin, and α-smooth muscle actin (α-SMA) expressions were assessed as mesenchymal markers. E-cadherin expression pattern was correlated with the disease pathology in that tubule segments showing the highest expression in control had much severer cyst formation in PCK rats. In PCK rats, E-cadherin and β-catenin in cystic tubules was attenuated and localized to lateral areas of cell-cell contact, whereas nuclear expression of Snail1 increased in parallel with cyst enlargement. Some epithelial cells in large cysts derived from these segments, especially in adjacent fibrotic areas, showed positive immunoreactivity for vimentin and fibronectin. In conclusion, these findings suggest that epithelial cells in cysts acquire mesenchymal features in response to cyst enlargement and participate in progressive renal fibrosis. Our study clarified the nephron segment-specific cyst profile related to EMT in PCK rats. EMT may play a key role in polycystic kidney disease.

Prognostic significance of claudin expression changes in breast cancer with regional lymph node metastasis

Adherent and tight junction molecules have been described to contribute to carcinogenesis and tumor progression. Additionally, the group of claudin-low tumors have recently been identified as a molecular subgroup of breast carcinoma. In our study, we examined the expression pattern of claudins, beta-catenin and E-cadherin in invasive ductal (IDCs) and lobular (ILCs) carcinomas and their corresponding lymph node metastases (LNMs). Tissue microarrays of 97 breast samples (60 invasive ductal carcinomas, 37 invasive lobular carcinomas) and their corresponding LNMs have been analyzed immunohistochemically for claudin-1, -2, -3, -4, -5, -7, beta-catenin and E-cadherin expression. The stained slides were digitalized with a slide scanner and the reactions were evaluated semiquantitatively. When compared to LNMs, in the IDC group beta-catenin and claudin-2, -3, -4 and -7 protein expression showed different pattern while claudin-1, -2, -3, -4 and -7 were differently expressed in the ILC group. Lymph node metastases developed a notable increase of claudin-5 expression in both groups. Decrease or loss of claudin-1 and expression of claudin-4 in lymph node metastases correlated with reduced disease-free survival in our patients. According to our observations, the expression of epithelial junctional molecules, especially claudins, is different in primary breast carcinomas compared to their lymph node metastases as demonstrated by immunohistochemistry. Loss of claudin junctional molecules might contribute to tumor progression, and certain claudin expression pattern might be of prognostic relevance.

E-cadherin and β-catenin expression in canine colorectal adenocarcinoma

E-cadherin and its associated cytoplasmic proteins, including β-catenin, have been examined as potential oncogenic markers due to the significant correlation between tumour dedifferentiation and the invasive capacity of epithelial tumours. The purpose of this study was to evaluate the expression of E-cadherin and β-catenin in canine colorectal cancer using immunohistochemistry and to examine the relationship between this expression and various clinicopathological variables. The expression pattern of E-cadherin and β-catenin was investigated in 44 colorectal canine carcinomas. In the intestinal mucosa of noncancerous areas, epithelial cells demonstrated equally strong membranous expression of E-cadherin and β-catenin localised to the cell–cell junctions. Reduced expression of E-cadherin and β-catenin was demonstrated in 75% and 81.8% of the colorectal carcinoma cases, respectively. The down-regulation of both E-cadherin and β-catenin was correlated with decreased differentiation and increased tumour grade. In addition, the expression of β-catenin was correlated with tumour size. These results suggest that dysfunction of the E-cadherin–catenin complex starts in the early stages of carcinogenesis and that the disruption of the tissue architecture is progressively associated with the invasion of the tumour.

Abstract 5186: Identification of novel cell-surface proteins associated with homotypic adhesion in human colon cancer cell lines

Abstract The loss of homotypic cell adhesion is one of several prerequisites for metastasis. This study aimed to characterize this process by comparing the adhesive properties and E-cadherin expression of a panel of eight human colon cancer cell lines. Homotypic adhesion was determined by cell dissociation assays. E-cadherin is generally considered the primary mediator of cell-cell adhesion in epithelial cells and epithelial-derived tumors, but E-cadherin mRNA and protein expression did not correlate with homotypic adhesion across the cell lines. Consequently, the mediation of adhesion in these cell lines must be more complex. To characterize this additional complexity, gene expression profiling was performed and a set of genes encoding transmembrane proteins was identified that correlated with adhesion across the cell lines. The functional relevance of these correlated genes in adhesion was confirmed by siRNA knockdown in SW480 colon cancer cells. Knockdown of either CD99 or CD99L2 led to a loss of homotypic adhesion, down-regulation of E-cadherin mRNA and protein levels and up-regulation of vimentin mRNA and protein levels. The expression patterns of E-cadherin and vimentin following gene knockdown is consistent with epithelial-mesenchymal transition (EMT). EMT is a transcriptional program active in both development and in tumor progression, which causes cells to have decreased adhesion, increased invasion, and increased motility. In contrast, knockdown of the correlated gene LRRC8B in SW480 cells led to a loss of homotypic adhesion but had no effect on the expression of either E-cadherin or vimentin, suggesting an EMT-independent mechanism. The cell-surface molecules CD99 and CD99L2 appear to be involved in a signaling and/or transcriptional network that helps maintain an epithelial phenotype, and loss of this network may be associated with EMT and cancer progression. To characterize this network, gene expression profiling was performed in SW480 cells following siRNA-mediated knockdown of either CD99 or CD99L2. Because these two cell-surface proteins are structurally related and displayed similar functional roles in adhesion, we hypothesized that they would share overlapping downstream transcriptional effects. Analysis of the gene expression data has identified a shared set of transcription factors whose expression is affected by the knockdown of either CD99 or CD99L2. The approach of correlating the adhesion characteristics and gene expression of a panel of colon cancer cell lines has identified a set of novel genes which are functionally involved in adhesion. Further investigation will help to identify the contributions of CD99, CD99L2 and LRRC8B to the homotypic adhesion process and clarify the downstream transcriptional networks involved in this facet of tumor progression. 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 5186.

Abstract 1494: Characterization of a novel pro-tumorigenic TGF-β RII mutation from oral squamous cell carcinoma

Abstract TGF-β signaling plays various roles in tumor progression. Tumor suppressive TGF- β signaling is involved in early steps of carcinogenesis through loss of function which leads to deregulated proliferation. On the contrary, TGF- β signaling could be pro-tumorigenic in later stages of carcinogenesis by promoting epithelial-mesenchymal transition (EMT). Most of the reported TGF- β receptor-II mutations were loss of tumor suppressor function mutations and no pro-tumorigenic TGF- β receptor-II mutation has been identified in human tumors. This study aimed to analyze a novel mutation of TGF- β receptor-II found in metastatic lymph node of oral squamous cell carcinoma. This mutant converts amino acid 227 from I to T and amino acid 236 from N to D of TGF- β receptor-II. Promoter assay using 3TP-lux reporter showed that 227/236 double mutation significantly increased both basal and TGF- β-induced luciferase activity as compared to wild type in DR-26, TGF- β receptor-II-defective mink lung epithelial cells. Stable expression of 227/236 mutant enhanced migration and invasion as well as cell growth of HSC-2 cells, human oral squamous cancer cell line whose TGF- β signaling is not growth inhibitory. In 227/236 mutant transfectant, E-cadherin expression is reduced whereas snail expression has not been changed significantly. In orthotopic xenograft model to monitor the tumor growth, 227/236 mutant transfectant formed significantly larger tumors as compared to wild type transfectant. But, unexpectedly, there was no difference in the expression pattern of involucrin and E-cadherin in these tumor tissues, suggesting that this mutation did not affect EMT in vivo model system. In the study we present a novel gain-of-function mutation of TGF- β receptor II, which increased TGF- β signaling and thereby induced tumor growth without affecting EMT in HSC-2 oral squamous cancer cells. This work was supported by a grant from the Korea Research Foundation Grant funded by the Korean Government (MOEHRD, Basic research promotion fund KRF-2005-005-J05901). 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 1494.

Abstract 3324: Epithelial mesenchymal transition is associated with chemoresistance of poorly differentiated hepatoma cells

Abstract BACKGROUND: Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide. It is the most rapidly increasing type of cancers in the US. Chemotherapy has been largely ineffective for HCC treatment, especially in cases with poorly-differentiated HCC. Cancer stem cells (CSCs) are a critical subpopulation that may be responsible for the initiation, progression, metastasis and recurrence of malignancies. CD133 and aldehyde dehydrogenase (ALDH) are useful markers to identify CSCs in solid tumors, such as lung and pancreatic cancers. AIMS: To separate CD133+/ALDHhigh cells in well-defined hepatoma cell lines, and to evaluate chemosentivity based on their CSC marker profile. METHODS: Hepatoma cell lines: HepG2, Hep3B, Huh-7, HLE, HLF and SKHep1 were separated into CD133+/ALDHhigh and CD133−/ALDHlow subpopulations by FACS. The resulting subpopulations were seeded on non-attachable plates for spheroid formation or used for chemosentivity assays. Epithelial mesenchymal transition (EMT) was determined by immunocytochemical staining of E-cadherin and vimentin. Gene expression of procollagen type I (α1) (Procoll-I) and transforming growth factor β1 (TGF-β1) was determined by quantitative RT-PCR. RESULTS: In well-differentiated hepatoma cell lines, HepG2, Hep3B and Huh-7, the positivity for CD133+/ALDHhigh was 1.1, 13.4 and 15.6%; whereas, poorly-differentiated hepatoma cells were almost all negative for these two markers. The positivity for CD133/EpCAM was 2.3, 10.3 and 18.3% in HepG2, Hep3B and Huh-7 cells, whereas it was almost negative in HLE, HLF and SKHep1 cells. FACS-enriched CD133+/ALDHhigh HepG2, Huh-7 and Hep3B cells were able to form spheroids in non-attachable culture plates; whereas their negative counterparts failed. In contrast, CD133−/ALDHlow SKHep1, HLF and HLE cells formed larger spheroids with negative α-feto protein staining. More CD133−/ALDHlow HLE cells survived in the exposure to cisplatin or doxorubicin than their positive counterparts (p&amp;lt;0.05-0.01). Moreover, CD133+/ALDHhigh HepG2, Hep3B and Huh-7 cells were positive for E-cadherin, but negative for vimentin; whereas, their CD133−/ALDHlow cells displayed an opposite expression pattern of E-cadherin and vimentin. CD133−/ALDHlow HLE, HLF and SKHep1 cells were E-cadherin-negative and vimentin-positive. In accordance, mRNA levels of Procoll-I and TGF-β1 in CD133−/ALDHlow HLE cells were one-fold higher than their positive counterparts. CONCLUSIONS: In well-differentiated hepatoma cells, CD133+/ALDHhigh or CD133+/EpCAM+ cells appear to be a CSC/progenitor subpopulation; whereas, in poorly-differentiated hepatoma cell lines which are negative for these CSC markers, EMT may be responsible for their chemoresistance. 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 3324.

Expression pattern of E-cadherin during development of the first tooth in zebrafish (Danio rerio)

Although the importance of cell adhesion in morphogenesis is already known for quite some time, there are remarkably few studies on the distribution and function of adhesion molecules in tooth development. We have chosen the zebrafish to study the role of specific cell adhesion molecules in the development and renewal of teeth. Zebrafish lack an oral dentition but have pharyngeal teeth which are renewed throughout life. Here we focus on the expression of E (epithelial)-cadherin during the development of the first tooth to develop in the dentition, 'initiator tooth' 4V1. E-cadherin is expressed exclusively in the pharyngeal epithelium and in the enamel organ throughout all stages of development of this first-generation tooth. Further studies are needed to

Wnt4/5a signalling coordinates cell adhesion and entry into meiosis during presumptive ovarian follicle development

Germ cells are the foundation of an individual, since they generate the gametes and provide the unique genome established through meiosis. The sex-specific fate of the germline in mammals is thought to be controlled by somatic signals, which are still poorly characterized. We demonstrate here that somatic Wnt signalling is crucial for the control of female germline development. Wnt-4 maintains germ cell cysts and early follicular gene expression and provides a female pattern of E-cadherin and beta-catenin expression within the germ cells. In addition, we find that Stra8 expression is downregulated and the Cyp26b1 gene is expressed ectopically in the partially masculinized Wnt-4-deficient ovary. Wnt-4 may control meiosis via these proteins since the Cyp26b1 enzyme is known to degrade retinoic acid (RA) and inhibit meiosis in the male embryo, and Stra8 induces meiosis in the female through RA. Reintroduction of a Wnt-4 signal to the partially masculinized embryonic ovary, in fact, rescues the female property to a certain degree, as seen by inhibition of Cyp26b1 and induction of Irx3 gene expression. Wnt-4 deficiency allows only 20% of the germ cells to initiate meiosis in the ovary, whereas meiosis is inhibited completely in the Wnt-4/Wnt-5a double mutant. These findings indicate a critical role for Wnt signalling in meiosis. Thus, the Wnt signals are important somatic cell signals that coordinate presumptive female follicle development.

Expression of E-Cadherin, Cox-2, P53 and BCL-2 in Prostate Carcinomas: Correlation with Tumor Differentiation and Metastatic Potential

ABSTRACTPrognostic factors of prostate cancer such as PSA, stage, Gleason grade, and surgical margins have limitations; they are inable to indicate metastatic potential. The aim of this study was to investigate expression of e-cadherin, cox-2, p53 and bcl-2 in prostate carcinomas, and to search association with tumor differentiation and metastatic potential.Eighty-seven prostate cancer specimens were retreived from tissue blocks embedded in parafin, and expression patterns of e-cadherin, cox-2, p53 and bcl-2 were investigated by immunoperoxidase method. Gleason scoring system was used for tumor grading, and expression patterns of these antibodies were compared among different tumor grades.Seven cases (8%) had well-differentiated, 39 (45%) had moderately differentiated, and 41 (47%) had poorly differentiated tumors. Metastases were present in 31 patients (35%). There was a statistically significant association between tumor differentiation and expression of e-cadherin or bcl-2 (p<0.01); however no association was found between tumor differentiation and expression of cox-2 or p53 (p>0.01). There was no association between expressions of e-cadherin, cox-2, p53 or bcl-2 and metastasis.E-cadherin expression is less frequent in poorly differentiated tumors; whereas bcl-2 expression is more frequent. However there is no relation with metastatic potential and expression of these markers. Expression of cox-2 and p53 is neither related to the degree of differentiation nor to the metastatic potential.

Lethal Giant Larvae2 Expression Is Reduced or Localized at Cytoplasm in Colon Adenomas and Adenocarcinomas

Background : The Scribble, Par and Crumbs polarity modules are essential for establishing and maintaining apicobasal cell polarity in epithelial cells. The aim of the present study was to investigate the expression pattern of Lethal giant larvae2 (Lgl2) in normal colonic epithelium and epithelial tumors and to examine the relationship between Lgl2 expression and clinicopathological parameters. Methods : We examined Lgl2 expression in 66 primary colon cancers and 20 adenomas by immunohistochemistry. Results : In normal colonic epithelium, Lgl2 was strongly expressed at the basolateral membrane of cells in the luminal surface but was not expressed at the base of crypts. The expression pattern of E-cadherin in normal epithelium was similar to that of Lgl2. In contrast, tumors did not express Lgl2 or showed diffuse cytoplasmic staining. The Lgl2 positive rate in tumors was significantly lower than in normal epithelium, and its negative rate in tumors was higher in tumors with abnormal E-cadherin expression than in tumors with positive membranous staining. Lgl2 staining intensity was significantly lower in tumor budding sites than in tumor centers. No significant differences were observed between Lgl2 and clinicopathological parameters. Conclusions : Lgl2 expression was reduced or localized at the cytoplasm in colon epithelial tumors, suggesting that a perturbation of Lgl2 expression frequently occurs in colon epithelial tumors.