E-cadherin complex and its abnormalities in human breast cancer

Transcriptomic study of gastrointestinal stromal tumors with liver metastasis

Introduction: GIST (gastrointestinal stromal tumor) is the most prominent mesenchymal neoplasms of the gastrointestinal tract, and liver is the most common metastasis site for GIST. The molecular mechanism leading to liver metastasis of GIST is currently unclear. Methods: With the goal of revealing the underlying mechanism, we performed whole-genome gene expression profiling on 18 pairs of RNA samples comprised of GIST tissues (with liver metastasis) and corresponding non-tumor tissues. After identifying differentially expressed gene, functional annotation and signal pathway analyses were conducted. GSE13861, datasets that compare GIST (without liver metastasis) with adjacent tissues, served as a comparison. Results: A total of 492 up-regulated genes and 629 down-regulated genes were identified as differentially expressed genes between liver metastasis tissues and non-tumor tissues. We characterized expression patterns of DEGs identified from our cohort and GSE13861 that show signatures of enrichment for functionality. In subsequent gene set enrichment analysis, differentially expressed genes were mainly enriched in Epithelial Mesenchymal Transition in both datasets. 493 genes were overlapped among our whole-genome gene expression profiling results and GSE13861, consisting 188 up-regulated genes and 305 down-regulated genes. By using CytoHubba plugin of Cytoscape, CDH1, CD34, KIT, PROM1, SOX9, FGF2, CD24, ALDH1A1, JAG1 and NES were identified as top ten hub genes in tumorigenesis and liver metastasis of GIST. higher expression levels of FGF2, JAG1, CD34, ALDH1A1 and the lower expression level of CDH1 were respectively associated with unfavorable overall survival. Meanwhile higher expression levels of CD34, FGF2, KIT, JAG1, ALDH1A were correlated with worse disease-free survival. Discussion: The present study may help to provide candidate pathways and targets for treatment of GIST and prevention methods to liver metastasis.

Lipids in the cell: organisation regulates function

Lipids are fundamental building blocks of all cells and play important roles in the pathogenesis of different diseases, including inflammation, autoimmune disease, cancer, and neurodegeneration. The lipid composition of different organelles can vary substantially from cell to cell, but increasing evidence demonstrates that lipids become organised specifically in each compartment, and this organisation is essential for regulating cell function. For example, lipid microdomains in the plasma membrane, known as lipid rafts, are platforms for concentrating protein receptors and can influence intra-cellular signalling. Lipid organisation is tightly regulated and can be observed across different model organisms, including bacteria, yeast, Drosophila, and Caenorhabditis elegans, suggesting that lipid organisation is evolutionarily conserved. In this review, we summarise the importance and function of specific lipid domains in main cellular organelles and discuss recent advances that investigate how these specific and highly regulated structures contribute to diverse biological processes.

Isoform expression patterns of EPHA10 protein mediate breast cancer progression by regulating the E-Cadherin and β-catenin complex

Overexpression of EPHA10 protein was reported in concomitance with clinical severity of breast cancer. In this study, we annotate overexpression of EPHA10 protein with changes of isoform expression as EphA10s (EPHA10 isoform 2) and EphA10 (EPHA10 isoform 3). In the process of malignant transformation, secretory protein EphA10s is in low expression, and pseudo-kinase EphA10 is overexpressed and cytoplasmically enriched. Down-regulated EphA10s blunts stabilization of membrane-associate β-catenin via the interaction with ephrin A5. Cytoplasmic EphA10 maintains phosphorylation of E-cadherin. Restoring isoform expression pattern by up-regulated EphA10s and down-regulated cytoplasmic EphA10 inhibits cell invasion and lymph node metastasis by strengthening the stability of the complex of E-cadherin and β-catenin in membrane. Taken together, we defined the novel interaction via expression patterns of EphA10s and EphA10 that promote malignant transformation of breast cancer, and demonstrated the potential benefit in clinical usage.

E-cadherin: Its dysregulation in carcinogenesis and clinical implications

E-cadherin is a transmembrane glycoprotein which connects epithelial cells together at adherens junctions. In normal cells, E-cadherin exerts its tumour suppressing role mainly by sequestering β-catenin from its binding to LEF (Lymphoid enhancer factor)/TCF (T cell factor) which serves the function of transcribing genes of the proliferative Wnt signaling pathway. Despite the ongoing debate on whether the loss of E-cadherin is the cause or effect of epithelial-mesenchymal transition (EMT), E-cadherin functional loss has frequently been associated with poor prognosis and survival in patients of various cancers. The dysregulation of E-cadherin expression that leads to carcinogenesis happens mostly at the epigenetic level but there are cases of genetic alterations as well. E-cadherin expression has been linked to the cellular functions of invasiveness reduction, growth inhibition, apoptosis, cell cycle arrest and differentiation. Studies on various cancers have shown that these different cellular functions are also interdependent. Recent studies have reported a rapid expansion of E-cadherin clinical relevance in various cancers. This review article summarises the multifaceted effect E-cadherin expression has on cellular functions in the context of carcinogenesis as well as its clinical implications in diagnosis, prognosis and therapeutics.

HOXA-10 and E-cadherin expression in the endometrium of women with recurrent implantation failure and recurrent miscarriage

OBJECTIVE

To compare the expression of HOXA-10 and E-cadherin in the endometrium of women with recurrent implantation failure (RIF), women with recurrent miscarriage (RM), and women with proven fertility (normal control; NC).

DESIGN

Observational cohort study.

SETTING

University assisted reproductive unit.

PATIENT(S)

Fifty women were recruited: 18 NC, 12 unexplained RIF, and 20 RM.

INTERVENTIONS(S)

None.

MAIN OUTCOME MEASURE(S)

Endometrial biopsy was precisely timed 7 days after LH surge. The expression of HOXA-10 and E-cadherin were examined by means of immunohistochemistry. H-Scores of staining intensity in the glandular epithelium and stroma were measured.

RESULT(S)

HOXA-10 signal was mainly localized in the nuclei of stroma cells and the cytoplasm of glandular epithelium cells. E-Cadherin signal was found only in the cytoplasm of glandular epithelium cells. The HOXA-10 H-scores in the RIF group and the RM group were significantly lower than in the control group in both the glandular epithelium and stroma. The E-cadherin H-scores in the RM group were also significantly lower than in the control group. Interestingly, there was a positive correlation between HOXA-10 and E-cadherin H-scores in all of the women examined.

CONCLUSION(S)

There is a positive correlation between levels of HOXA-10 and E-cadherin expression in the endometrium, both of which are significantly reduced in women with RIF and RM compared with fertile control women. The findings suggest a potential role of HOXA-10 and E-cadherin in the implantation processes and altered expression in women with reproductive failure.

Nuclear accumulation of CDH1 mRNA in hepatocellular carcinoma cells

Expression of E-cadherin has a central role in maintaining epithelial morphology. In solid tumors, reduction of E-cadherin results in disruption of intercellular contacts. Consequently, cells lose adhesive properties and gain more invasive mesenchymal properties. Nevertheless, the mechanism of E-cadherin regulation is not completely elucidated. Here we analyzed the distribution of E-cadherin expression at the cell level in human hepatocellular carcinoma, in which human liver paraffin blocks from 25 hepatocellular carcinoma patients were prepared from cancerous (CA) and noncancerous areas (NCA). In situ hybridization (ISH) was performed to detect E-cadherin and hypoxia-induced factor-1α (HIF1α) mRNAs and immunohistochemistry to stain E-cadherin protein. In parallel, RNA was extracted from CA and NCA, and E-cadherin and HIF1α were quantified by quantitative reverse transcription PCR. ISH revealed abundant E-cadherin mRNA in nuclei of hepatocellular carcinoma cells (HCCs), whereas immunohistochemistry showed depletion of E-cadherin protein from these areas. In sections of NCA, E-cadherin mRNA was also found in the cytosol, and E-cadherin protein was detected on the membrane of cells. Experiments in cell lines confirmed E-cadherin mRNA in nuclei of cells negative for E-cadherin protein. HIF1α expression is elevated in CAs, which is associated with a clear cytosolic staining for this mRNA. Our results demonstrate that E-caderhin mRNA is selectively retained in nuclei of HCCs, whereas other mRNAs are still exported, suggesting that translocation of E-cadherin mRNA from nuclei to cytoplasm has a role in regulating E-cadherin protein levels during epithelial mesenchymal transition.

Tissue invasion and metastasis: Molecular, biological and clinical perspectives

Cancer is a key health issue across the world, causing substantial patient morbidity and mortality. Patient prognosis is tightly linked with metastatic dissemination of the disease to distant sites, with metastatic diseases accounting for a vast percentage of cancer patient mortality. While advances in this area have been made, the process of cancer metastasis and the factors governing cancer spread and establishment at secondary locations is still poorly understood. The current article summarizes recent progress in this area of research, both in the understanding of the underlying biological processes and in the therapeutic strategies for the management of metastasis. This review lists the disruption of E-cadherin and tight junctions, key signaling pathways, including urokinase type plasminogen activator (uPA), phosphatidylinositol 3-kinase/v-akt murine thymoma viral oncogene (PI3K/AKT), focal adhesion kinase (FAK), β-catenin/zinc finger E-box binding homeobox 1 (ZEB-1) and transforming growth factor beta (TGF-β), together with inactivation of activator protein-1 (AP-1) and suppression of matrix metalloproteinase-9 (MMP-9) activity as key targets and the use of phytochemicals, or natural products, such as those from Agaricus blazei, Albatrellus confluens, Cordyceps militaris, Ganoderma lucidum, Poria cocos and Silybum marianum, together with diet derived fatty acids gamma linolenic acid (GLA) and eicosapentanoic acid (EPA) and inhibitory compounds as useful approaches to target tissue invasion and metastasis as well as other hallmark areas of cancer. Together, these strategies could represent new, inexpensive, low toxicity strategies to aid in the management of cancer metastasis as well as having holistic effects against other cancer hallmarks.

Altered distribution and expression pattern of E-cadherin in hepatocellular carcinomas: correlations with prognosis and clinical features

OBJECTIVE

E-cadherin has been identified as a tumor suppressor in many types of carcinoma. However, some studies recently suggested that the role and expression of E-cadherin might be more complex and diverse. In the present study, we evaluated the prognostic value of E-cadherin expression with reference to levels in membranes and cytoplasm, and the membrane/cytoplasm ratio, in hepatocellular carcinomas (HCCs) after curative hepatectomy.

METHODS

The expression of E-cadherin was assessed by immunohistochemistry in HCC tissue microarrays from 125 patients, and its prognostic values and other clinicopathlogical data were retrospectively analyzed. Patients were followed for a median period of 43.7 months (range 1 to 126 months).

RESULTS

Univariate analysis demonstrated that a high membrane/cytoplasm (M/C) ratio of E-cadherin expression was associated with poor overall survival (OS) (P =0.001) and shorter time to recurrence (TTR) (P =0.038), as well as tumor size, intrahepatic metastasis, and TNM stage. In contrast, neither membrane nor cytoplasmic expression of E-cadherin was related with OS and TTR. Furthermore, multivariate analysis confirmed the M/C ratio to be an independent predictor of OS (P =0.031). ?2 tests additionally showed that the M/C ratio of E-cadherin expression was related with early stage recurrence (P =0.012), rather than later stage recurrence.

CONCLUSION

The M/C ratio of E-cadherin expression is a strong predictor of postoperative survival and is associated with early stage recurrence in patients with HCC.

RY10-4 suppressed metastasis of MDA-MB-231 by stabilizing ECM and E-cadherin

In the article, we investigated the anti-metastasis mechanism of RY10-4, an anti-tumor compound derived from protoapigenone, in breast tumor cells MB-MDA-231. The analog of protoapigenone with an unaromatic B-ring was verified to suppress the proliferation of several tumor cells by previous research that also showed that several tumor progression such as inducing apoptosis and anti-angiogenesis could be acted on by RY10-4. In the article, we investigated the mechanism about how RY10-4 suppressed the invasion of MDA-MB-231. Firstly, the transwells assays with and without matrigel were adapted to evaluate the anti-metastasis and anti-invasion activity. Much research had demonstrated that the ECM and E-cadherin/β-catenin complex play an important role in cell adhesion and the formation of the cell skeleton, and as we knew the abnormal and absent expression of ECM and E-cadherin/β-catenin complex are found in many malignant cells. The result demonstrated that the amount and distribution of E-cadherin/β-catenin complex were backed on track by RY10-4, and the expression of MMP-2/9 in MDA-MB-231, which functions as a major negative factor of ECM, was down-regulated after co-cultured with RY10-4. Furthermore the pathway related to MMP-2/9 and E-cadherin was assessed by the western blot. As the results showed, the MAPK pathway and the spread of β-catenin were affected by RY10-4 to exert the anti-metastasis on MDA-MB-231. Collectively, the research revealed a novel anti-tumor ability of RY10-4 by inhibiting migration and invasion in MDA-MB-231.

E-cadherin polymorphisms and susceptibility to arsenic-related skin lesions in West Bengal, India

OBJECTIVES

Although suppression of E-cadherin gene (CDH1) expression and exposure to arsenic have separately been associated with skin lesions, the combined effects of this "gene-environment" interaction have not been explored previously.

STUDY DESIGN

A population-based cross-sectional survey.

METHOD

This study involved 100 cases with skin lesions and 100 controls who were family members with no lesions. The subjects were recruited from villages and hamlets in northern Nadia Province, West Bengal. Each participant was required to undergo a detailed face-to-face interview; provide spot urine sample; provide saliva sample; and sign a consent form. The type and severity of skin lesions were assessed during a general medical examination of each participant in the field. The following 16 single nucleotide polymorphisms (SNPs) of the CDH1 were measured using DNA extracted from saliva samples: rs16260, rs5030625, rs155364, rs155808, rs155807, rs2303646, rs2059254, rs9925923, rs12919719, rs7188750, rs9989407, rs7196495, rs7196661, rs13689, rs12599393, and rs1862748.

RESULTS

The main effects of SNPs on the risk for skin lesions were borderline for rs7196661 (p-value=0.092), rs7196495 (p-value=0.090), and rs12919719 (p-value=0.065); the strongest association was found for rs9989407 (p-value=0.058). Several SNPs, however, showed that the T>T genotype carriers are at higher relative risk for skin lesions compared to carriers of the C>C or C>T genotypes; these results need to be confirmed in a larger study. The main effects of some of the SNPs and genotype frequencies on the severity of skin lesions were found to be relatively weak.

CONCLUSIONS

This is the first study that indicates that CDH1 polymorphisms can contribute to the etiology of premalignant skin lesions in people chronically exposed to arsenic in drinking water, and that this gene may be a factor in individual susceptibility to cutaneous diseases.

Cadherin-catenin complex dissociation in lobular neoplasia of the breast

E-cadherin (E-CD) inactivation with loss of E-CD-mediated cell adhesion is the hallmark of lesions of the lobular phenotype. E-CD is typically absent by immunohistochemistry in both lobular carcinoma in situ (LCIS) and invasive lobular lesions, suggesting it occurs early in the neoplastic process. In laboratory models, downstream post-transcriptional modifiers such as TWIST and SNAIL contribute to the dissociation of the intracellular component of the cadherin-catenin complex (CCC), resulting in tumor progression and invasion. We hypothesized that complete CCC dissociation may play a role in lobular neoplasia progression. Here we explore the relationship between loss of E-CD and dissociation of the CCC in pure LCIS and LCIS associated with invasive cancer. Fresh-frozen tissues were obtained from 36 patients undergoing mastectomy for pure LCIS (n = 11), LCIS with ILC (n = 18) or LCIS with IDC (n = 7). Individual lesions were subject to laser-capture microdissection and gene-expression analysis (Affymetrix HG-U133A 2.0). Immunohistochemistry for ER,PR,HER2, E-CD,N-CD,α-,β-, and phosphoβ-catenin, TWIST, and SNAIL were evaluated in normal, in situ, and invasive components from matched formalin-fixed paraffin-embedded samples (n = 36). CCC-dissociation was defined as negative membranous E-CD, α- and β-catenin expression. E-CD was negative in all LCIS and ILC lesions, and positive in all normal and IDC lesions. Membranous α and β-catenin expressions decreased with the transition from LCIS to ILC (pure LCIS 82%; LCIS w/ILC 28%; ILC 0%), while TWIST expression increased (pure LCIS low; LCIS w/ILC moderate; ILC high). Gene expression paralleled IHC-staining patterns with a stepwise downregulation of E-CD, α and β-catenins from normal to LCIS to invasive lesions, and increasing expression of TWIST from normal to LCIS to ILC. Loss of E-CD expression is an early event in lobular neoplasia. Decreasing membranous catenin expression in tandem with increasing levels of TWIST across the spectrum of lobular lesions suggests that CCC dissociation is a progressive process.

Parotid carcinoma metastasis to parietal meningioma: case report and molecular biologic considerations

INTRODUCTION

A combination of factors as the meningioma's rich vascularity, its low metabolic rate, immunologic factors and the molecular pattern explains the affinity of some cancer metastasis to seed inside meningiomas. In this context, the importance of surface adhesion molecules is of rising interest.

CASE REPORT

We report the exceptional case of a parotid carcinoma metastasis within a meningioma. A 68-year old male was referred to our hospital with headache and progressive right hemiparesis. Four years before he was diagnosed with parotid gland cancer for which he had undergone parotidectomy, radiation, neck dissection and chemotherapy. MRI showed a left sided high-parietal, dural-based, extraaxial, contrast enhancing tumor which was consequently removed microsurgically. Histological examination revealed a dedifferentiated parotid carcinoma metastasis inside a microcystic meningioma WHO grade I. Mechanisms that have been suggested to be responsible for metastasis into meningioma include meningiomas' rich vascularity, slow growth, their high collagen and lipid content, immunologic factors but also the expression of certain surface adhesion molecules, in particular E-cadherin. In the presented case E-cadherin immunostaining was strongly positive in the metastatic tissue that invaded the meningioma in a droppled-like fashion. We discuss the potential role of E-cadherin, re-expression of a modified E-cadherin complex and the potential importance of mesenchymal surface proteins in the pathophysiology of carcinoma metastasis into meningioma.

CONCLUSION

Surface proteins of carcinoma cells might play a key role regarding their affinity to seed inside meningiomas. This might be a leading mechanism to the multifactorial process of carcinoma-to-meningioma metastasis.

E-cadherin-160 C/A promoter polymorphism and risk of pancreatic carcinoma in Chinese population

Recent studies have implicated E-cadherin-160C/A single-nucleotide polymorphism (SNP) in susceptibility to and early onset of some cancers. We investigated the role of E-cadherin-160 C/A SNP in Chinese pancreatic carcinoma patients without dominant family history by genotyping 254 patients and 101 controls. The risk of cancer for CC genotype individuals was less than half that of AA individuals [odds ratio (OR) = 0.41; 95%confidence interval (95%CI) = 0.18-0.96]. Furthermore, patients with the CC and CA genotypes whose tumors were stages III (T(4)N(x)M(0)) and IV (T(x)N(x)M(1)) (OR = 0.38; 95%CI = 0.17-0.83), poorly differentiated (OR = 0.28; 95%CI = 0.09-0.84), and left-sided (OR = 0.45; 95%CI 0.21-0.98) were associated with significantly lower risk than AA patients. Young (60 years old or younger) AA patients had a 5-year lower mean age at onset than CC/CA patients (P = 0.02). Young male AA patients had worse disease-specific survival than CC/CA patients (P = 0.002). Thus, contrary to Canadians and Portuguese, the AA (rather than CC) genotype is associated with increased susceptibility and advanced pancreatic carcinoma in Chinese patients, suggesting a more complex relationship between the SNP and pancreatic carcinoma risk, possibly modulated by population differences.

Gene silencing of beta-catenin in melanoma cells retards their growth but promotes the formation of pulmonary metastasis in mice

Altered expression of beta-catenin, a key component of the Wnt signaling pathway, is involved in a variety of cancers because increased levels of beta-catenin protein are frequently associated with enhanced cellular proliferation. Although our previous study demonstrated that gene silencing of beta-catenin in melanoma B16-BL6 cells by plasmid DNA (pDNA) expressing short-hairpin RNA targeting the gene (pshbeta-catenin) markedly suppressed their growth in vivo, gene silencing of beta-catenin could promote tumor metastasis by the rearranging cell adhesion complex. In this study, we investigated how silencing of beta-catenin affects metastatic aspects of melanoma cells. Transfection of B16-BL6 cells with pshbeta-catenin significantly reduced the amount of cadherin protein, a cell adhesion molecule binding to beta-catenin, with little change in its mRNA level. Cadherin-derived fragments were detected in culture media of B16-BL6 cells transfected with pshbeta-catenin, suggesting that cadherin is shed from the cell surface when the expression of beta-catenin is reduced. The mobility of B16-BL6 cells transfected with pshbeta-catenin was greater than that of cells transfected with any of the control pDNAs. B16-BL6 cells stably transfected with pshbeta-catenin (B16/pshbeta-catenin) formed less or an equal number of tumor nodules in the lung than cells stably transfected with other plasmids when injected into mice via the tail vein. However, when subcutaneously inoculated, B16/pshbeta-catenin cells formed more nodules in the lung than the other stably transfected cells. These results raise concerns about the gene silencing of beta-catenin for inhibiting tumor growth, because it promotes tumor metastasis by reducing the amount of cadherin in tumor cells.

Real time PCR analyses of expression of E-cadherin, alpha-, beta- and gamma-catenin in human breast cancer for predicting clinical outcome

Background

The E-cadherin catenin system acts as an invasion suppressor of epithelial malignancies. However, it is debatable whether expression of E-cadherin or catenins is a useful prognostic marker in invasive breast cancer.

Methods

We measured the expression of E-cadherin and catenins (α-, β-, γ-catenin) in human breast carcinomas using real time quantitative polymerase chain reaction (Q-PCR) and investigated whether the expression levels were associated with known tumour variables or patient survival (median follow-up 72.2 months). RNA from frozen sections of breast tissue (tumour n = 124, background normal tissue n = 33) was reverse transcribed, quantified and analysed by Q-PCR with results expressed as number of copies of transcript/50 ng RNA.

Results

There was no statistically significant difference in the expression of E-cadherin and catenins (α-, β-, γ-catenin)in the 33 paired normal background and tumour tissues. The expression of E-cadherin, α-, β-, and γ-catenin in node positive tumours was similar to node-negative tumours. E-cadherin, α-, β-, and γ-catenin expression in breast tumours was not related to Nottingham Prognostic Index (NPI). There was no significant difference in the expression of E-cadherin, α-, β-, γ-catenin between the various TNM stages. None of the molecular markers significantly influenced survival. Lymph node status was the only significant predictor of survival.

Conclusion

Using real time quantitative PCR there was no difference in the expression of E-cadherin, α-, β-, γ-catenin between tumour and normal breast tissue. Furthermore, measurement of expression of these molecules was not of prognostic value in predicting long term outcome of women with breast cancer.

Dissecting lipid raft facilitated cell signaling pathways in cancer

Cancer is one of the most devastating disorders in our lives. Higher rate of proliferation than death of cells is one of the essential factors for development of cancer. The dynamicity of cell membrane plays some vital roles in cell survival and cell death, including protection, endocytosis, signaling, and increases in mechanical stability during cell division, as well as decrease of shear forces during separation of two cells after division, and cell separation from tissues for cancer metastasis. Within the membrane, there are specialized domains, known as lipid rafts. A raft can coordinate various signaling pathways. Recent data on the proteomics of lipid rafts/caveolae have highlighted the enigmatic role of various signaling proteins in cancer development. Analysis of these data of raft proteome from various tumors, cancer tissues, and cell lines cultured without and with therapeutic agents, as well as from model rafts revealed that there may be two subsets of raft assemblage in cell membrane. One subset of raft is enriched with cholesterol-sphingomyeline-ganglioside-cav-1/Src/EGFR (hereafter, "chol-raft") that is involved in normal cell signaling, and when dysregulated promotes cell transformation and tumor progression; another subset of raft is enriched with ceramide-sphingomyeline-ganglioside-FAS/Ezrin (hereafter, "cer-raft") that generally promotes apoptosis. In view of this, and to focus insight into the cancer cell physiology caused by the lipid rafts mediated signals and their receptors, and the downstream transmitters, either proliferative (for example, EGF and EGFR) or death-inducing (for example, FASL and FAS), and the precise roles of some therapeutic drugs and endogenous acid sphingomylenase in this scenario in in situ transformation of "chol-raft" into "cer-raft" are summarized and discussed in this contribution.

Loss of epithelium cadherin expression is associated with reduced overall survival and disease-free survival in early-stage squamous cell cervical carcinoma

Epithelium cadherin (E-cad) is important for cell-to-cell adhesion of epithelial cells. Impairment of E-cad may have a role in the development and spreading of different malignancies and associated with poor differentiation, increased invasiveness, and poor prognostic factors in nongynecological carcinomas. However, prognostic significance of E-cad expression has not been investigated properly in cervical squamous cell carcinoma (SCC). The objective of this study was to investigate the association between reduced E-cad expression and clinicopathologic variables of cervical carcinoma. Specimens from 53 consecutive patients with stage IB-IIA SCC were evaluated immunohistochemically for E-cad expression, and the results were compared to grade, lymphvascular space invasion (LVSI), deep stromal involvement (DSI), parametrial involvement, lymph node metastasis, recurrences, and survival. Patients were divided into two groups arbitrarily: E-cad expression less than 10% (group 1) and E-cad expression more than 10% (group 2). There was no significant relationship between E-cad expression and DSI, LVSI, lymphatic metastasis. However, there was significant relationship between reduced E-cad expression and parametrial involvement (P= 0.024). Kaplan-Meier survival analysis revealed that reduced E-cad expression is significantly associated with reduced overall survival (OS) and disease-free survival (DFS). Furthermore, Cox regression analysis revealed that reduced E-cad expression is significantly associated with OS (P= 0.004, RR = 6.08, 95% CI: 1.75-21.1) and recurrences (P= 0.027, RR = 1.75, 95% CI: 1.06-2.88). We conclude that loss of E-cad expression is significantly associated with reduced OS and DFS in patients with SCC. Therefore, it might be used as an indicator of aggressive clinical behavior and tailoring aggressive adjuvant therapy in early-stage SCC. Further studies with larger number of patients are needed to evaluate the clinical significance of reduced E-cad expression in SCC.

MDM2 promotes cell motility and invasiveness by regulating E-cadherin degradation

Gene amplification and protein overexpression of MDM2, which is often found in certain types of cancers, indicate that MDM2 plays an important role in tumorigenesis. Interestingly, several clinical reports have demonstrated that amplification of the MDM2 gene correlates with the metastatic stage. Using an antibody array assay, we identified E-cadherin as an MDM2-binding protein and confirmed that E-cadherin is a substrate for the MDM2 E3 ubiquitin ligase. We demonstrate that MDM2 interacts in vivo with E-cadherin, resulting in its ubiquitination and degradation. This regulation appears to be clinically relevant, as we found a significant correlation between high MDM2 and low E-cadherin protein levels in resected tumor specimens recovered from breast cancer patients with lymph node metastases. Ectopic expression of MDM2 in breast cancer cells was found to disrupt cell-cell contacts and enhance cell motility and invasive potential. We found that E-cadherin and MDM2 colocalized on the plasma membrane and in the early endosome, where ubiquitin moieties were attached to E-cadherin. Blocking endocytosis with dominant-negative mutants of dynamin abolished the association of MDM2 with E-cadherin, prevented E-cadherin degradation, and attenuated cell motility as observed by fluorescence microscopy. Thus, we provide evidence to support a novel role for MDM2 in regulating cell adhesions by a mechanism that involves degrading and down-regulating the expression of E-cadherin via an endosome pathway. This novel MDM2-regulated pathway is likely to play a biologically relevant role in cancer metastasis.

The management of lobular carcinoma in situ (LCIS). Is LCIS the same as ductal carcinoma in situ (DCIS)?

Lobular carcinoma in situ was first described over 60 years ago. Despite the long history, it continues to pose significant difficulties in screening, diagnosis, management and treatment. This is partly due its multi-focal and bilateral presentation, an incomplete understanding of its biology and natural history and perpetuation of misconceptions gathered over the last decades. In this review, the working group on behalf of EUSOMA has attempted to summarise the current thinking and management of this interesting lesion.

Familial gastric cancer - aetiology and pathogenesis

Gastric cancer is the second most common cause of cancer death worldwide. It is estimated that 5-10% of gastric cancer cases have a familial association; however, knowledge concerning the genetic predisposition to familial gastric cancer is currently limited. In this chapter we discuss what is known about the aetiology and pathogenesis of both the diffuse and intestinal forms of familial gastric cancer. We focus particularly on hereditary diffuse gastric cancer because the discovery of germ-line E-cadherin mutations in a number of affected families has opened the prospect of identifying gene carriers, with implications for clinical management. The interplay of other conventional risk factors, such as Helicobacter pylori infection, with genetic factors is also discussed. It is hoped that understanding the genetic basis for familial gastric cancer will facilitate the development of clinically useful screening and preventative procedures.

Expression of e-cadherin in high-risk breast cancer

PURPOSE

E-cadherin expression is diverse, and differences in patient characteristics may produce variability in expression. Whereas some studies have indicated that downregulation of e-cadherin, associated with loss of cellular adhesiveness, was correlative with poor prognosis and metastasis, other studies have failed to confirm this. The present study uses a highly homogenous population of patients at high-risk for breast cancer, on the basis of ethnic and socio-economic status, to examine the relationship between e-cadherin and other prognostic markers in breast cancer.

METHODS

Immunohistochemical staining was undertaken for estrogen (ER) and progesterone (PR) receptors, epidermal growth factor receptor 2 (Her-2), p53, vascular endothelial factor (VEGF), and hypoxia inducible factor 1alpha (HIF-1alpha) and the levels of these markers was compared to e-cadherin expression in a high-risk African-American patient population.

RESULTS

E-cadherin expression persisted into the later stagers of the disease, and was strongly associated with Her-2 and HIF-1alpha expression, but not p53, ER/PR or VEGF.

CONCLUSIONS

In contrast to other studies on heterogeneous populations, e-cadherin is preserved in aggressive tumors in this high-risk population. The ethnic and socio-economic risk stratification needs to be accounted for in studies correlating markers and prognosis.

Prognostic significance of E-cadherin protein expression in pathological stage I-III endometrial cancer

PURPOSE

Decreased expression of E-cadherin in endometrial cancer cells is associated with adverse prognostic features. This study aimed to evaluate the prognostic significance of decreased E-cadherin expression in patients with endometrial cancer.

EXPERIMENTAL DESIGN

Between 1992 and 1999, 102 endometrial cancer patients with stage I-III disease underwent primary surgery at the University of Chicago. Representative tissue specimens were immunostained with a monoclonal antibody to E-cadherin. A semiquantitative evaluation scale was developed based on the percentage of endometrial cancer cells with membranous E-cadherin staining. Tissue sections were scored as "3" if >75%, "2" if 25-75%, "1" if 5-25%, and "0" if <5% of cells stained. E-Cadherin staining was correlated with overall survival (OS), cause-specific survival (CSS), progression-free survival (PFS), and extrapelvic progression. Multivariate Cox proportional hazards modeling was used to estimate hazard ratios, controlling for clinicopathological characteristics and adjuvant treatment. Median follow-up for the study group was 58.5 months.

RESULTS

E-Cadherin staining was scored as 0, 1, 2, and 3 in 29.4%, 18.6%, 26.5%, 25.5% of cases, respectively. E-Cadherin expression was positively correlated with myometrial invasion (Kendall tau: 0.30, P < 0.01), and negatively correlated with grade (Kendall tau: -0.13, P = 0.15) and papillary serous or clear cell histology (Kendall tau: -0.14, P = 0.12). Five-year actuarial OS, CSS, PFS, and extrapelvic recurrence rates for negative (score = 0), heterogeneous (score = 1-2), and positive (score = 3) staining were as follows: OS, 69.2 versus 75.7 versus 81.0% (P = 0.64); CSS, 78.8 versus 91.2 versus 95.5% (P = 0.19); PFS, 69.1 versus 88.6 versus 92.2% (P = 0.079), and extrapelvic progression, 20.8 versus 7.3 versus 4.0% (P = 0.17). On multivariate Cox regression, a higher E-cadherin expression score was associated with decreased overall mortality [hazard ratio (HR), 0.59; 95% confidence interval (CI), 0.34-1.03; P = 0.066), and statistically significant decreases in endometrial cancer mortality (HR, 0.23; 95% CI, 0.055-0.94; P = 0.040), disease progression (HR, 0.28; 95% CI, 0.10-0.77; P = 0.014), and extrapelvic recurrence (HR, 0.24; 95% CI, 0.062-0.97; P = 0.045).

CONCLUSIONS

Decreased E-cadherin expression is an independent prognostic factor for disease progression and mortality in pathological stage I-III endometrial cancer. Evaluation of E-cadherin expression may aid in the selection of patients for more aggressive adjuvant therapy.

Cytoplasmic localization of p120ctn and E-cadherin loss characterize lobular breast carcinoma from preinvasive to metastatic lesions

Accumulating evidences indicate that p120 catenin, a member of the E-cadherin (E-CD)/catenin adhesion complex, plays a role in tumor invasion. To establish the expression pattern of p120 in breast cancer, we analysed 326 breast tissue biopsies by tissue microarray. Most of the lobular tumors (88%) showed exclusive cytoplasmic localization, and 6% of them also had p120 nuclear staining. Cytoplasmic p120 strongly associated with complete loss of E-CD and beta-catenin not only in lobular carcinoma and its metastases but also in atypical lobular hyperplasias. In the latter, loss of heterozygosity of E-CD gene was also observed. Complete loss of E-CD and cytoplasmic and nuclear p120 staining was also observed in primary lobular cancer cell cultures generated by us. In ductal tumors, by contrast, reduction of p120 and E-CD in membrane was very common (57 and 53%, respectively), whereas cytoplasmic p120 staining was rarely seen. This simultaneous reduction of membranous E-CD and p120 was not associated with increased Src kinase activity. To demonstrate that cytoplasmic p120 localization was a consequence of the absence of E-CD, the endogenous E-CD was re-expressed in MDA-231 cells by 5-Aza-2'-deoxycytidine (5Aza) treatment. After treatment, p120 shifted from the cytoplasm to the membrane, where it colocalized with endogenous E-CD. Additionally, suppressing E-CD expression in Madin-Darby canine kidney cells by stable transfection of the transcriptional repressors Snail, E47 or Slug, provokes p120 cytoplasmic localization and p120 isoform switching. In conclusion, abnormal cytoplasmic and nuclear localization of p120, which are mediated by the absence of E-CD, characteristically occur in the early stages of lobular breast cancer and are maintained during tumor progression to metastasis. Consequently, p120 may be an important mediator of the oncogenic effects derived from E-CD inactivation, including enhanced motility and invasion, in lobular breast cancer.

Metastatic Foci of Signet Ring Cell Carcinoma in a Tubular Adenoma of the Colon

We describe a case of adenomatous polyp of the colon that harbored small foci of signet ring cell carcinoma. The patient was a 64-year-old woman with end-stage renal disease and sepsis who underwent colonoscopy to evaluate the possibility of pseudomembranous colitis. A polyp was found incidentally in the right colon and a biopsy was performed. Histologic examination of the polyp revealed typical features of tubular adenoma without evidence of high-grade dysplasia. However, 2 small foci of signet ring cell carcinoma were identified that infiltrated the lamina propria. In contrast to adenomatous epithelium, the signet ring cells were immunohistochemically positive for cytokeratin 7 and negative for cytokeratin 20, suggesting a metastasis rather than a primary tumor. Multiple random biopsies from the right and left colon, as well as the ileum, exhibited no histologic evidence of malignancy. Subsequently, signet ring cell carcinoma with similar morphology and identical immunophenotype was detected in biopsies from the endometrium, an unusual location for primary signet ring cell carcinoma. Preliminary workup excluded the breast as a possible primary site, but further investigation was not possible because of the patient's death with no autopsy granted. To the best of our knowledge, this is the first reported case of metastatic signet ring cell carcinoma to an adenomatous polyp of the colon. This case illustrates the necessity of submitting all polyps entirely and the importance of examining them carefully.