Loss Of Membranous E-cadherin Research Articles

Abstract C054: Hypoxia promotes a durable epithelial-mesenchymal transition in pancreas cancer through a histone methylation-MAPK signaling axis

Abstract Pancreatic ductal adenocarcinoma (PDAC) tumors are poorly vascularized and exhibit regions of hypoxia. Here, we demonstrate that this feature of the tumor microenvironment promotes epithelial-mesenchymal transition (EMT), which occurs early in PDAC and drives chemoresistance, and we identify the underlying signaling mechanism. Analysis of publicly-available human transcriptomics and proteomics demonstrated that PDAC cells or tumors enriched in mesenchymal markers were also enriched in markers of hypoxia or HIF activity. Furthermore, in lineage-traced autochthonous, orthotopic patient-derived xenograft, and orthotopic or subcutaneous implanted cell line models of PDAC, hypoxic tumor tissue regions were enriched for neoplastic cells that had undergone EMT. In cell culture experiments, PDAC cells from human and mouse tumors exhibited an ability to undergo EMT in response to 1% O2, with loss of membranous E-cadherin, increased vimentin protein expression, and transcriptional changes indicative of both hypoxia and EMT. Moreover, EMT in response to hypoxia was substantially more persistent than that observed in response to growth factors, and a hypoxia fate mapping system revealed that once-hypoxic cells could retain mesenchymal characteristics outside hypoxic tumor regions. To understand the mechanism for EMT in response to low oxygen tension, we constructed a multivariable linear regression model of the dependence of the hypoxic gene signature on different gene sets in PDAC ductal cells, which identified MAPK signaling as the most important feature. Consistent with the model inference, in both in vitro and in vivo settings, hypoxic cells showing evidence of EMT displayed elevated MAPK signaling. We further demonstrated that MAPK activation in hypoxia was potentiated by suppressed activity of a histone demethylase and concomitant loss of protein phosphatase expression, which reinforced the mechanism by stabilizing the expression of a histone methyltransferase. Thus, this study identifies a tumor microenvironment-initiated mechanism leading to EMT and nominates several potential drug targets whose antagonism may promote PDAC chemoresponse. Citation Format: Brooke A. Brown, Paul J. Myers, Sara J. Adair, Jason R. Pitarresi, Shiv Sah Teli, Peppi Karppinen, Ben Z. Stanger, Todd W. Bauer, Matthew J. Lazzara. Hypoxia promotes a durable epithelial-mesenchymal transition in pancreas cancer through a histone methylation-MAPK signaling axis [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C054.

A human Barrett's esophagus organoid system reveals epithelial-mesenchymal plasticity induced by acid and bile salts.

The pathogenesis of subsquamous intestinal metaplasia (SSIM), in which glands of Barrett's esophagus (BE) are buried under esophageal squamous epithelium, is unknown. In a rat model of reflux esophagitis, we found that columnar-lined esophagus developed via a wound-healing process involving epithelial-mesenchymal plasticity (EMP) that buried glands under ulcerated squamous epithelium. To explore a role for reflux-induced EMP in BE, we established and characterized human Barrett's organoids and sought evidence of EMP after treatment with acidic bile salts (AB). We optimized media to grow human BE organoids from immortalized human Barrett's cells and from BE biopsies from seven patients, and we characterized histological, morphological, and molecular features of organoid development. Features and markers of EMP were explored following organoid exposure to AB, with and without a collagen I (COL1) matrix to simulate a wound-healing environment. All media successfully initiated organoid growth, but advanced DMEM/F12 (aDMEM) was best at sustaining organoid viability. Using aDMEM, organoids comprising nongoblet and goblet columnar cells that expressed gastric and intestinal cell markers were generated from BE biopsies of all seven patients. After AB treatment, early-stage Barrett's organoids exhibited EMP with loss of membranous E-cadherin and increased protrusive cell migration, events significantly enhanced by COL1. Using human BE biopsies, we have established Barrett's organoids that recapitulate key histological and molecular features of BE to serve as high-fidelity BE models. Our findings suggest that reflux can induce EMP in human BE, potentially enabling Barrett's cells to migrate under adjacent squamous epithelium to form SSIM.NEW & NOTEWORTHY Using Barrett's esophagus (BE) biopsies, we established organoids recapitulating key BE features. During early stages of organoid development, a GERD-like wound environment-induced features of epithelial-mesenchymal plasticity (EMP) in Barrett's progenitor cells, suggesting that reflux-induced EMP can enable Barrett's cells to migrate underneath squamous epithelium to form subsquamous intestinal metaplasia, a condition that may underlie Barrett's cancers that escape detection by endoscopic surveillance, and recurrences of Barrett's metaplasia following endoscopic eradication therapy.

Abstract 2691: Extracellular adenosine signaling in pancreatic cancer: New therapeutic strategies

Abstract Introduction: Approximately 90% of cancer-related deaths are due to tumor metastasis. Metastasis is a very complex process with several steps including cancer cell motility, invasion, circulation, extravasation, and metastatic colonization/outgrowth. For these diverse processes to take place, a cancer cell needs to acquire and maintain plasticity. Of relevance, a hallmark of metastatic initiation is the loss of membranous E-cadherin and the induction of the Epithelial to Mesenchymal Transition (EMT). During EMT, cancer cells not only exhibit protein expression changes, such as in E-cadherin, but also undergo dramatic reprogramming evident at the chromatin level. Elucidating mechanisms underlying metastasis is especially important in the context of pancreatic ductal adenocarcinoma (PDAC), as this lethal disease typically presents at metastatic stages. Using a PDAC mouse model whereby we endow the cells to undergo EMT, we find that metastatic capability is significantly augmented. We have utilized RNA sequencing from this model to elucidate underlying mechanisms of action and have prioritized CD73/Nt5e. CD73 is involved in the sensing and conversion of extracellular AMP to adenosine. The extracellular adenosine pathway has been shown to create an immunosuppressive environment, yet investigation of this pathway in the context of pancreatic cancer is lacking. Methods: To study the extracellular adenosine pathway in the context of PDAC, we use several different model systems including patient-derived 3D organoids, an autochthonous mouse model of pancreatic cancer (Pdx1-cre; LSL-KrasG12D/+; LSL-Trp53R172H; Rosa26LSL-YFP herein KPCY), and 2D cell culture. Results: We have been investigating the role of CD73 in PDAC and have uncovered novel cancer cell intrinsic and cell extrinsic roles. We demonstrate that CD73 is overexpressed in PDAC, and its overexpression is significantly associated with poor overall survival. Using our 3D organoids, we show that CD73 inhibition induces cell death. In addition, our CRISPR-Cas9 CD73 knockout lines have decreased metastatic abilities in vivo. Our preliminary work also suggests synergistic efficacy of anti-CD73 therapy when combined with inhibition of the adenosine receptors, Adora2a and Adora2b, which are related to CD73 biology. SUMMARY. Using a mouse model of PDAC with increased metastatic capability, we have unveiled the importance of CD73 expression and function in the context of PDAC. Our recent data suggests that CD73 activity has important roles, not only in the cancer cells but in other cells within the tumor microenviroment, and that targeting CD73 be very effective therapeutically. Citation Format: Anna M. Chiarella, Jason R. Pitarresi, Gulam Manji, Anil K. Rustgi. Extracellular adenosine signaling in pancreatic cancer: New therapeutic strategies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2691.

Mesalamine and azathioprine modulate junctional complexes and restore epithelial barrier function in intestinal inflammation

Disruption of mucosal structure and barrier function contribute to the pathogenesis of inflammatory bowel disease (IBD). Efficacy of therapy in IBD is based on endoscopic mucosal healing, which occurs by a dynamic interplay of epithelial cell regeneration, migration and differentiation. Both mesalamine (5-ASA) and azathioprine (AZTP) promote this process through mechanisms not clearly understood. We examined molecular pathways implicated in epithelial barrier function that were altered by 5-ASA and AZTP. Paracellular permeability induced by inflammatory mediators was mitigated by both compounds through restoration of cellular anchoring complexes. 5-ASA and AZTP induced rearrangement and membranous localization of junctional proteins and modulated genes involved in tight junctions. Intestinal organoids from wildtype-mice treated with TNF-α and IL-10- deficient-mice displayed impaired epithelial barrier with loss of membranous E-cadherin and reduced Desmoglein-2 expression. These effects were counteracted by 5-ASA and AZTP. Unlike AZTP that exhibited antiproliferative effects, 5-ASA promoted wound healing in colon epithelial cells. Both affected cellular senescence, cell cycle distribution and restricted cells in G1 or S phase without inducing apoptosis. This study provides mechanistic evidence that molecular actions of 5-ASA and AZTP on intestinal epithelia are fundamental in the resolution of barrier dysfunction.

Histopathological tumor invasion of the mesenterico-portal vein is characterized by aggressive biology and stromal fibroblast activation

BackgroundMesenterico-portal vein resection (PVR) during pancreatoduodenectomy for pancreatic head cancer was established in the 1990s and can be considered a routine procedure in specialized centers today. True histopathologic portal vein invasion is predictive of poor prognosis. The aim of this study was to examine the relationship between mesenterico-portal venous tumor infiltration (PVI) and features of aggressive tumor biology. MethodsPatients receiving PVR for pancreatic ductal adenocarcinoma of the pancreatic head were identified from a prospectively maintained database. Immunohistochemical staining of tumor tissue was performed for the markers of epithelial–mesenchymal transition (EMT) E-Cadherin, Vimentin and beta-Catenin. Morphology of cancer-associated fibroblasts (CAFs) was assessed as inactive or activated. Statistical calculations were performed with MedCalc software. ResultsIn total, 41 patients could be included. Median overall survival was 25 months. PVI was found in 17 patients (41%) and was significantly associated with loss of membranous E-Cadherin in tumor buds (p = 0.020), increased Vimentin expression (p = 0.03), activated CAF morphology (p = 0.046) and margin positive resection (p = 0.005). ConclusionOur findings suggest that PVI is associated with aggressive tumor biology and disseminated growth less amenable to margin-negative resection.

Abstract 3937: Comparative genomic hybridization reveals complex genomic changes in plasmacytoid urothelial carcinoma

Abstract Introduction The WHO classification of 2004 defined several histologic subtypes of urothelial carcinoma (UC) such as plasmacytoid UC (PUC). Since this definition, molecular characterization of these different tumor types has gained increasing attention. For the majority of histologic variants, it seems that they are associated with an even worse clinical outcome than conventional UC. However, PUC in particular is reported to be associated with an aggressive clinical course and advanced disease at the time of diagnosis. Nevertheless, genomic characterization of PUC, which examined genomic imbalances and chromosomal aberrations, is still missing. Material and Methods We analyzed formalin-fixed archival tissue of 25 PUCs using metaphase comparative genomic hybridization (CGH) for detecting genomic imbalances. Aberrant chromosomal regions were defined as characteristic when they were found in at least 20% of the tumors analyzed. Representative genes in aberrant chromosomal regions were additionally analyzed for copy number variations (CNV) using quantitative PCR to explore their possible roles in PUC carcinogenesis. Results Chromosomal aberrations were detected in every PUC analyzed and the average number of aberrations was 10.24 (ranging from 1-15). Characteristic aberrations were gains on 1q (48%), 3p (20%), 6p (32%), 11q (72%), 15q (36%), 16q (44%), 17p (76%), 17q (88%), and 20q (88%) and losses on 2q (24%) 4p (36%), 4q (84%), 5q (44%), 6q (68%), 13q (20%), and Xq (52%). PCR based analysis of CNV for CCND1 (11q13) showed a deletion in 73% of the cases. CDH1 (16q22) was deleted in 72% and amplified in 5%. ERBB2 (17q12) displayed remarkably few copy number alterations, with only 14% showing an amplification. SNAI1 (20q13) showed reduced gene copy numbers in 59.1% of the cases, while no copy number gains were detected. FOXO3 (6q21) exhibited the lowest number of copy number alterations, with 9% of all cases showing an amplification. Conclusions In PUCs, the frequency of aneuploidy and the complexity of genomic changes per tumor are greater than those described in conventional UC. The aberrations described in PUC involve the same regions that are associated with aggressive biological behavior in conventional UC. Gains on 11q, 17q, 17p and 20q and losses on 4q and 6q affect the majority of PUCs and seem to harbor important chromosomal regions for PUC carcinogenesis. Large-scale deletions on chromosome 9 were not detected. CNV analysis indicates heterozygous deletion of CDH1 as one underlying mechanism of loss of membranous E-cadherin in PUC. Loss of CCND1 and SNAI1 are common molecular features and could contribute to the aggressive biological behavior of PUC. Acknowledgements This study was supported by a grant from the ELAN Funds of the University Hospital Erlangen to BK and RS. Citation Format: Sven Wach, Christina Ellmann, Robert Stoehr, Katrin Weigelt, Peter J. Goebell, Frank Kunath, Helge Taubert, Arndt Hartmann, Bernd Wullich, Bastian Keck. Comparative genomic hybridization reveals complex genomic changes in plasmacytoid urothelial carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3937. doi:10.1158/1538-7445.AM2015-3937

Role of epithelial-mesenchymal transition markers in triple-negative breast cancer.

Triple-negative breast cancers (TNBCs) are a heterogeneous group of breast tumours that are often associated with adverse pathological characteristics, poorer clinical outcomes and lack of targeted therapeutic options. Epithelial-mesenchymal transition, which plays a crucial role in tumour development and progression, is characterised by a transition from epithelial to mesenchymal phenotype and loss of proteins involved in maintaining cell junctions. We aimed to correlate protein expression of E-cadherin, Snail2 and transforming growth factor beta (TGF-β) with clinicopathological parameters and survivals of a series of patients with TNBC. The study cohort comprised 767 TNBCs diagnosed at the Department of Pathology, Singapore General Hospital from 1994 to 2012. Immunohistochemistry was performed on sections cut from tissue microarrays using the polymeric method. Staining intensity and percentage of positive tumour cells were evaluated and correlated with clinicopathological findings and clinical outcomes. Loss of E-cadherin expression, Snail2 positivity, cytoplasmic and nuclear expression of TGF-β were observed in 265 (35.2 %), 241 (32.0 %), 272 (36.2 %) and 262 (34.8 %) tumours, respectively. Histological grade significantly correlated with Snail2 positivity (P < 0.001) and loss of membranous E-cadherin expression (P = 0.003). Nuclear expression of TGF-β was inversely correlated with histological grade (P = 0.010). Median follow-up was 73 months, with a maximum of 236 months. Despite a graphical curve for earlier recurrence in patients with tumours harbouring a combinational phenotype of loss of membranous E-cadherin and positive Snail2 expression, there was no statistical significance. Similarly for women with tumours expressing cytoplasmic TGF-β, graphical representation showed poorer metastasis-free survival but without statistical significance. Loss of membranous E-cadherin and positive Snail2 expression are significantly associated with high-grade TNBCs. More work is needed to improve understanding of the role of TGF-β in TNBC.

Cancer stem cell and epithelial-mesenchymal transition markers predict worse outcome in metaplastic carcinoma of the breast.

Metaplastic breast carcinomas are known to overexpress markers of epithelial-mesenchymal transition and cancer stem cells. We evaluated their immunohistochemical expression, correlating with clinicopathological parameters and survival outcomes. The study cohort comprised 63 cases diagnosed at the Department of Pathology, Singapore General Hospital. Tumor size, grade, lymph node stage, and metaplastic components were reviewed. Immunohistochemistry was performed on sections cut from tissue microarray blocks. Antibodies to ER, PR, HER2, CK14, EGFR, 34βE12, cancer stem cell markers (CD44, CD24, ALDH1A1), epithelial-mesenchymal transition markers (Twist and E-cadherin), were applied. Survival outcomes were correlated with immunohistochemical findings. T2 tumors accounted for 74.7% of cases, with grade 3 tumors predominating (71.4%). Triple negativity occurred in 87.3%, and basal-like subtype in 69.8% of tumors. CD44+, CD44+CD24-, ALDH1A1+, loss of membranous E-cadherin (Ecadloss) and positive Twist expression was found in 82.5, 73.0, 77.8, 54.0, and 57.1% of tumors, respectively. Combinational phenotypes of CD44+EcadlossTwist+, CD44+CD24-EcadlossTwist+, and ALDH1A1+EcadlossTwist+ were observed in 28.6, 25.4, and 2.6% of tumors. Histologic grade was significantly correlated with E-cadherin loss (p=0.042), Twist positivity (P=0.001), CD44+EcadlossTwist+ (P=0.010), CD44+CD24-EcadlossTwist+ (P=0.018), and ALDH1A1+EcadlossTwist+(P=0.010). Lymph node stage was significantly associated with CD44+EcadlossTwist+(P=0.044) and CD44+CD24-EcadlossTwist+ (P=0.044). Basal-like phenotype was significantly correlated with CD44 expressing (P=0.004) and CD44+CD24- tumors (P=0.049). Tumors harboring CD44+EcadlossTwist+ and CD44+CD24-EcadlossTwist+ phenotypes disclosed early recurrence (P=0.027, P=0.006) and poorer overall survival (P=0.037, P=0.006), respectively. Expression of cancer stem cell and epithelial-mesenchymal transition markers in metaplastic breast cancers correlates with adverse pathological parameters and outcome.

Abstract 4844: Extracellular hyaluronan accumulation by hyaluronan synthase 3 promotes pancreatic cancer growth and modulates tumor microenvironment via epithelial-mesenchymal transition

Abstract Pancreatic cancer is one of most deadly cancers with a 5-year survival rate of 6%. Accumulation of hyaluronan (HA) is found in about 87% of human pancreatic adenocarcinomas, and removal of HA suppresses tumor growth in HA-rich preclinical models. In a transgenic pancreatic cancer mouse model (LSL-KrasG12D/+;LSLTrp53R172H/+;Pdx-1-Cre, KPC), removal of HA by pegylated human recombinant PH20 hyaluronidase (PEGPH20) inhibits tumor growth and increases survival in combination with gemcitabine compared to gemcitabine monotherapy. In this study, we explored the role of HA synthesizing (HAS) enzymes HAS2 and HAS3 and HA accumulation in pancreatic cancer tumor growth and remodeling of tumor microenvironment. HAS2 and HAS3 were overexpressed in BxPC3 human pancreatic cancer cells using lentiviral vectors. Stable HAS2 and HAS3 overexpressing pancreatic cancer cell lines secreted more HA to culture medium and produced larger pericellular HA matrices than parental BxPC3 cells. In vivo, overexpression of HAS2 or HAS3 led to an increase in BxPC3 xenograft tumor growth (peritibial i.m. tumor model) compared to parental cells. Interestingly, overexpression of HAS3 was more effective to enhance tumor growth than overexpression of HAS2. In addition, massive accumulation of extracellular HA was found in HAS3 overexpressing tumors while HAS2 overexpressing tumors contained both extracellular and intracellular HA. Treatment with PEGPH20 removed the majority of extracellular HA and induced a 87% reduction of tumor volume in BxPC3 HAS3 model (p&amp;lt;0.001) but had weaker effect on BxPC3 HAS2 (33%, p&amp;lt;0.001) and BxPC3 tumors (36%, p&amp;lt;0.01). Accumulation of extracellular HA was associated with enriched tumor stroma, loss of membranous E-cadherin and accumulation of cytoplasmic β-catenin in pancreatic cancer cells, suggesting HA-induced epithelial-mesenchymal transition (EMT). Removal of HA by PEGPH20 reversed the remodeling of the tumor stroma and induced translocation of E-cadherin and β-catenin to the plasma membrane.Translocation of E-cadherin was also observed in the KPC pancreatic tumors after PEGPH20 treatment. In conclusion, accumulation of extracellular HA by HAS3 overexpression favors tumor growth and leads to a strong response to PEGPH20 in a pancreatic cancer xenograft model. Deposition of extracellular HA is associated with optimization of the tumor microenvironment and EMT. Depletion of HA by PEGPH20 reverses changes in the tumor stroma and induces translocation of epithelial markers to the plasma membrane. Citation Format: Anne Kultti, Chunmei Zhao, Susan Zimmerman, Ryan J. Osgood, Yanling Chen, Rebecca Symons, Ping Jiang, Curtis B. Thompson, David A. Tuveson, Gregory I. Frost, H Michael Shepard, Zhongdong Huang. Extracellular hyaluronan accumulation by hyaluronan synthase 3 promotes pancreatic cancer growth and modulates tumor microenvironment via epithelial-mesenchymal transition. [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 4844. doi:10.1158/1538-7445.AM2014-4844

Correlated analysis of semi-quantitative immunohistochemical features of E-cadherin, VEGF and CD105 in assessing malignant potentiality of oral submucous fibrosis

Oral submucous fibrosis, a potentially premalignant condition for oral squamous cell carcinoma, manifests both non-dysplastic and dysplastic grades. Early and specific identification of its malignant potentiality suffers from diagnostic limitations that may be addressed by correlated molecular pathology attributes having histopathological backdrop. Present study correlates expressional alteration in prime epithelial marker E-cadherin, with neo-angiogenic molecules viz. VEGF and CD105 for elucidation of malignant potentiality in different stages of oral submucous fibrosis. Sixty-eight incision biopsies from normal oral mucosa (n=10), non-dysplastic (n=18) and different dysplastic grades (n=40) of oral submucous fibrosis were semi-quantitatively analyzed for immunohistochemical expressions of E-cadherin (membranous and cytoplasmic), VEGF and CD105 which were further statistically correlated. The loss of membranous E-cadherin with increase in cytoplasmic accumulation in differentiative layers of epithelium through the progression of dysplasia was noted along with up-regulation in VEGF expressions. The number of CD105+ blood vessels and their major axis also showed significant increase from non-dysplasia toward higher grades of dysplasia. The positive correlation between deregulated expression of epithelial cell–cell adhesion molecule and increase in neo-angiogenic attributes of oral submucous fibrosis with increase in dysplastic grades indicated elucidatory potential of molecular expression features in assessment of malignant potentiality in oral submucous fibrosis.

Clinical Significance of Altered Expression of β-Catenin and E-Cadherin in Oral Dysplasia and Cancer: Potential Link with ALCAM Expression

BackgroundPerturbations in cell adhesion molecules are linked to alterations in cadherin-catenin complexes and likely play major roles in invasion and metastasis; their impact on early precancerous stages remains yet unknown. We showed ALCAM overexpression in early oral lesions and its cytoplasmic accumulation in oral squamous cell carcinoma (OSCC) to be a predictor of disease progression and poor prognosis. This study tested the hypothesis that alterations in E-cadherin and β -catenin expressions are early events in oral tumorigenesis, associated with disease prognosis, and correlate with perturbations in ALCAM expression.MethodsExpressions of E-cadherin and β-catenin were analyzed in the same cohort of 105 OSCCs, 76 oral lesions and 30 normal oral tissues by immunohistochemistry and correlated with clinicopathological parameters and prognosis. The effect of siRNA mediated ALCAM knockdown on E-cadherin and β -catenin was determined using western blot, confocal microscopy and RT-PCR analysis in oral cancer cells.ResultsSignificant loss of membranous E-cadherin and β-catenin expression was observed from normal, hyperplasia, dysplasia to OSCCs (ptrend <0.001); and correlated with cytoplasmic ALCAM accumulation in OSCCs (p = 0.006). Multivariate analysis revealed β-catenin membrane loss and ALCAM/β-cateninnuclear/cytoplasmic accumulation to be significant predictors for late clinical stage (p<0.001, OR = 8.7; p = 0.006, OR = 9.9, respectively) and nodal metastasis (p = 0.003, OR = 3.8; p = 0.025, OR = 3.4 respectively). Cox’s regression showed E-cadherin membrane loss/ALCAM cytoplasmic expression [p<0.001; HR = 4.8] to be independent adverse prognosticators in OSCCs. siRNA mediated silencing of ALCAM resulted in concurrent increase in E-cadherin and β-catenin both at the transcript and protein levels.ConclusionsLosses of E-cadherin and β-catenin expressions are early events in oral tumorigenesis; their associations with aggressive tumor behavior and disease recurrence underscore their potential as prognostic markers. Correlation of loss of E-cadherin and β-catenin with cytoplasmic ALCAM accumulation both in vitro and in in vivo suggests that these dynamic changes in cell adhesion system may play pivotal role in oral cancer.

Regional differences in prostaglandin E2 metabolism in human colorectal cancer liver metastases

BackgroundProstaglandin (PG) E2 plays a critical role in colorectal cancer (CRC) progression, including epithelial-mesenchymal transition (EMT). Activity of the rate-limiting enzyme for PGE2 catabolism (15-hydroxyprostaglandin dehydrogenase [15-PGDH]) is dependent on availability of NAD+. We tested the hypothesis that there is intra-tumoral variability in PGE2 content, as well as in levels and activity of 15-PGDH, in human CRC liver metastases (CRCLM). To understand possible underlying mechanisms, we investigated the relationship between hypoxia, 15-PGDH and PGE2 in human CRC cells in vitro.MethodsTissue from the periphery and centre of 20 human CRCLM was analysed for PGE2 levels, 15-PGDH and cyclooxygenase (COX)-2 expression, 15-PGDH activity, and NAD+/NADH levels. EMT of LIM1863 human CRC cells was induced by transforming growth factor (TGF) β.ResultsPGE2 levels were significantly higher in the centre of CRCLM compared with peripheral tissue (P = 0.04). There were increased levels of 15-PGDH protein in the centre of CRCLM associated with reduced 15-PGDH activity and low NAD+/NADH levels. There was no significant heterogeneity in COX-2 protein expression. NAD+ availability controlled 15-PGDH activity in human CRC cells in vitro. Hypoxia induced 15-PGDH expression in human CRC cells and promoted EMT, in a similar manner to PGE2. Combined 15-PGDH expression and loss of membranous E-cadherin (EMT biomarker) were present in the centre of human CRCLM in vivo.ConclusionsThere is significant intra-tumoral heterogeneity in PGE2 content, 15-PGDH activity and NAD+ availability in human CRCLM. Tumour micro-environment (including hypoxia)-driven differences in PGE2 metabolism should be targeted for novel treatment of advanced CRC.

Epigenetic inactivation of the E-cadherin gene in eyelid sebaceous gland carcinoma

E-cadherin and β-catenin are crucial components of the cell-cell adhesion complex. Their loss has often been associated with tumour metastasis and poor clinical outcome. Both loss of E-cadherin at the cell membrane and a stabilizing mutation in CTNNB1 (β-catenin gene) have been associated with ovarian, colorectal, hepatocellular and nonmelanoma skin cancer, such as squamous and basal cell carcinomas. Absence of E-cadherin may be caused by promoter hypermethylation of the E-cadherin gene (CDH1). To determine the role of E-cadherin promoter hypermethylation and CTNNB1 gene mutation in the aggressive behaviour of sebaceous gland carcinoma of the eyelid. Thirty-six cases of sebaceous gland carcinoma were subjected to E-cadherin methylation-specific polymerase chain reaction and mutational analysis for the CTNNB1 gene. E-cadherin and β-catenin staining was evaluated by immunohistochemistry. Results were correlated with the clinicopathological features of sebaceous gland carcinoma. nMethylation of the E-cadherin promoter region was detected in 72% of eyelid sebaceous gland carcinoma cases and loss of E-cadherin immunostaining in 83%. E-cadherin promoter hypermethylation showed a significant association with the loss of membranous E-cadherin (P = 0·038) and it was of borderline significance with reduced disease-free survival (P = 0·05). It was also found to be associated with advanced age (73%), tumour size ≥ 2 cm (77%), orbital invasion (83%), lymph node metastasis (60%), tumour recurrence (60%) and poor histological differentiation (90%). DNA sequencing revealed no stabilizing β-catenin gene mutation in sebaceous gland carcinoma. Loss of membranous β-catenin was observed in 61% cases, which associated significantly with both E-cadherin promoter methylation (P = 0·0262) and loss of E-cadherin membranous localization (P=0·0015). Epigenetic inactivation of the E-cadherin gene causes loss of membrane-bound E-cadherin and could contribute to the reduced disease-free survival in eyelid sebaceous gland carcinoma. Mutations in the β-catenin gene do not seem to be involved in the pathogenesis of eyelid sebaceous gland carcinoma.

Wnt-pathway activation in intestinal-type sinonasal adenocarcinoma

Intestinal-type sinonasal adenocarcinoma (ITAC) is an epithelial cancer of the sinonasal sinuses that shows histological similarity to colorectal cancer (CRC) and share chronic inflammation as a possible etiological factor. The Wnt-pathway is one of the most important tumourigenic pathways in CRC. The aim of this study was to investigate if the Wnt-pathway is activated in ITAC. Protein expression profiles of E-cadherin, β-catenin, c-myc and cyclin D1 were analysed by immunohistochemistry in 83 samples of ITAC, organized into tissue microarray blocks. Nuclear β-catenin expression was observed in 31% of the cases and was twice as frequent in papillary/colonic ITAC compared to solid/mucinous subtypes. Loss of membranous β-catenin staining occurred in 24% and loss of membranous E-cadherin in 6% of the cases and this was more prominent in mucinous types. Strong c-myc and cyclin D1 expression was observed in 30% and 4% of the cases, respectively. Nuclear β-catenin expression was significantly related to poor clinical outcome, independent from established factors as tumour stage and histological type. The presence of nuclear β-catenin in 31% of patients with ITACs indicated that in a subset of patients, the Wnt-pathway is active and conveys a worse prognosis.

ILK expression in human basal cell carcinoma correlates with epithelial–mesenchymal transition markers and tumour invasion

Epithelial-mesenchymal transition (EMT) has been known to play a significant role in tumour progression. Integrin-linked kinase (ILK) has been recently added to the growing list of EMT regulators that control some aspect of carcinogenesis. The aim was to study ILK expression and its relevance to EMT markers in human basal cell carcinoma (BCC). Paraffin-embedded tissue sections from 100 human BCC cases were processed by immunohistochemistry for the expression of ILK, E-cadherin, Snail, beta-catenin and alpha-smooth muscle actin (alpha-SMA). ILK overexpression was observed in 100% of cases and strongly correlated with tumour invasion and infiltrative BCC. Loss of membranous E-cadherin was found in 71% of cases while nuclear immunoreactivity for E-cadherin was also observed in 90% of the tumours. Snail, nuclear beta-catenin and alpha-SMA expression was detected in 100%, 99% and 97% of tumours, respectively. Aberrant expression of E-cadherin, nuclear beta-catenin and alpha-SMA correlated with BCC tumour invasion. Interestingly, there was a significant correlation between ILK expression and all the EMT markers examined. ILK overexpression in BCC is implicated in tumour progression probably through the induction of an EMT-related molecular profile. Nuclear localization of E-cadherin in BCC is also associated with aggressive tumour features.

Expression analysis of E-cadherin, Slug and GSK3β in invasive ductal carcinoma of breast

BackgroundCancer progression is linked to a partially dedifferentiated epithelial cell phenotype. The signaling pathways Wnt, Hedgehog, TGF-β and Notch have been implicated in experimental and developmental epithelial mesenchymal transition (EMT). Recent findings from our laboratory confirm that active Wnt/β-catenin signaling is critically involved in invasive ductal carcinomas (IDCs) of breast.MethodsIn the current study, we analyzed the expression patterns and relationships between the key Wnt/β-catenin signaling components- E-cadherin, Slug and GSK3β in IDCs of breast.ResultsOf the 98 IDCs analyzed, 53 (54%) showed loss/or reduced membranous staining of E-cadherin in tumor cells. Nuclear accumulation of Slug was observed in 33 (34%) IDCs examined. Loss or reduced level of cytoplasmic GSK3β expression was observed in 52/98 (53%) cases; while 34/98 (35%) tumors showed nuclear accumulation of GSK3β. Statistical analysis revealed associations of nuclear Slug expression with loss of membranous E-cadherin (p = 0.001); nuclear β-catenin (p = 0.001), and cytoplasmic β-catenin (p = 0.005), suggesting Slug mediated E-cadherin suppression via the activation of Wnt/β-catenin signaling pathway in IDCs. Our study also demonstrated significant correlation between GSK3β nuclear localization and tumor grade (p = 0.02), suggesting its association with tumor progression.ConclusionThe present study for the first time provided the clinical evidence in support of Wnt/β-catenin signaling upregulation in IDCs and key components of this pathway - E-cadherin, Slug and GSK3β with β-catenin in implementing EMT in these cells.

Nuclear Accumulation of E-Cadherin Correlates with Loss of Cytoplasmic Membrane Staining and Invasion in Pituitary Adenomas

Context: Loss of the cell adhesion protein E-cadherin is associated with invasion and metastasis in a number of malignancies. Recent studies have highlighted that loss of E-cadherin cell membrane expression may be accompanied by its detection in the nucleus, suggesting cellular redistribution during neoplasia. Pituitary tumors, although typically benign, may be locally invasive, and loss of membranous E-cadherin has been reported as a marker of invasion in prolactinomas. Objective: Our objective was to study E-cadherin expression in pituitary adenomas, specifically whether nuclear redistribution occurs in this setting. Methods: Immunohistochemistry, RT-PCR, and direct sequencing were performed. Results: Strong cytoplasmic membrane staining was present in all eight normal samples but completely absent in 21 of 44 adenomas (48%) with weak staining in an additional 11 adenomas using an antibody against the extracellular domain of E-cadherin. To identify nuclear translocation of the protein, immunohistochemistry was performed using an antibody against the cytoplasmic domain. Nuclear staining was present in 38 of 44 adenomas (86%) and absent in normal tissue. Nuclear E-cadherin inversely correlated with loss of E-cadherin cytoplasmic membrane staining and was associated with tumor invasion (P = 0.009). To investigate the mechanism of nuclear redistribution of E-cadherin, we performed RT-PCR of mRNA and sequenced tumor DNA. E-cadherin mRNA expression was reduced in only one of 30 samples (3%). No mutations were detected. Conclusions: E-cadherin was frequently lost at the cytoplasmic membrane but detected in the nucleus, suggesting that cleavage of the extracellular domain and nuclear translocation of E-cadherin is a common event that may determine local invasion in pituitary adenomas.

Nuclear Accumulation of E-Cadherin Correlates with Loss of Cytoplasmic Membrane Staining and Invasion in Pituitary Adenomas

Loss of the cell adhesion protein E-cadherin is associated with invasion and metastasis in a number of malignancies. Recent studies have highlighted that loss of E-cadherin cell membrane expression may be accompanied by its detection in the nucleus, suggesting cellular redistribution during neoplasia. Pituitary tumors, although typically benign, may be locally invasive, and loss of membranous E-cadherin has been reported as a marker of invasion in prolactinomas. Our objective was to study E-cadherin expression in pituitary adenomas, specifically whether nuclear redistribution occurs in this setting. Immunohistochemistry, RT-PCR, and direct sequencing were performed. Strong cytoplasmic membrane staining was present in all eight normal samples but completely absent in 21 of 44 adenomas (48%) with weak staining in an additional 11 adenomas using an antibody against the extracellular domain of E-cadherin. To identify nuclear translocation of the protein, immunohistochemistry was performed using an antibody against the cytoplasmic domain. Nuclear staining was present in 38 of 44 adenomas (86%) and absent in normal tissue. Nuclear E-cadherin inversely correlated with loss of E-cadherin cytoplasmic membrane staining and was associated with tumor invasion (P = 0.009). To investigate the mechanism of nuclear redistribution of E-cadherin, we performed RT-PCR of mRNA and sequenced tumor DNA. E-cadherin mRNA expression was reduced in only one of 30 samples (3%). No mutations were detected. E-cadherin was frequently lost at the cytoplasmic membrane but detected in the nucleus, suggesting that cleavage of the extracellular domain and nuclear translocation of E-cadherin is a common event that may determine local invasion in pituitary adenomas.

Correlation between the expression abnormalities of E-cadherin-β-catenin complex and lymph node metastasis (LNM) in early gastric cancer

15105 Background: Therapy for early gastric cancer (GC) varies according to risk of LNM. When the possibility of LNM is very remote, the primary lesion can be resected by the minimally invasive endoscopic surgery only. Therefore, useful parameters predicting LNM are needed. E-cadherin, a component of the cell-cell junctional structure, is known to correlate with GC. In vitro, previous studies elucidated that disorders of cell-cell junction increased the potential of metastasis, and that phosphorylation of β-catenin by c-erbB-2 induced loss of membranous E-cadherin and β-catenin, resulting in junctional structure disorders. Here we evaluated significance of analysis of these molecules in LNM prediction in early GC. Methods: The clinicopathological features and immunohistochemical expressions of E-cadherin, β-catenin, and c-erbB-2 in the primary lesion were studied in 28 patients (LNM +ve group: 14, LNM1 -ve group: 14) selected from 272 patients who underwent radical surgery for early GC between April 2000 to March 2004 at our hospital. All the patients consented to use of their stomach tissues for the clinical study afterwards. Statistical analysis was performed by t-test or χ2 test. Results: The clinicopathological features showed no significant differences between both groups. Loss of the membranous E-cadherin was noticed in 12 (85%) of the 14 LNM +ve patients, and in 8 (57%) of the 14 LNM -ve patients (p=0.209). This result was more remarkable in the intestinal type GC as the corresponding figures were 83% (5 of 6 ) and 16% (1 of 6) (p=0.083), respectively. Loss of the membranous β-catenin also showed a remarkable similar trend in the intestinal type GC, and the corresponding figures were 100% (6 of 6) and 50% (3 of 6) (p=0.182), respectively. Two patients showed over-expression of c-erbB2 and nuclear accumulation of β-catenin, and both had intestinal type GC with LNM. Conclusions: These results suggested that the same molecular signal pathway - as in vitro - including E-cadherin, β-catenin, and c-erbB2 induced LNM in early GC (intestinal type). We concluded that analysis of the expressions of these molecules is useful for not only LNM prediction but also determination of the therapeutic modality especially in intestinal type early GC. No significant financial relationships to disclose.

Prognostic significance of the wnt signalling pathway molecules APC, β‐catenin and E‐cadherin in colorectal cancer—a tissue microarray‐based analysis

To investigate dysregulation of the wnt signalling pathway by assessing beta-catenin expression/increasing expression and loss of cytoplasmic adenomatous polyposis coli (APC) and membranous E-cadherin in colorectal cancer (CRC) and determining the prognostic significance of these variables. Unselected, non-consecutive CRC resections (n = 1420) were subdivided into three groups: mismatch repair (MMR)-proficient, MLH1- and presumed hereditary non-polyposis colonic cancer (HNPCC). Immunohistochemical analysis of beta-catenin expression (0% versus > 0%) and increasing expression (increasing percentage-positivity) and loss of APC and E-cadherin was performed using the tissue microarray technique. In MMR-proficient CRC, increased nuclear beta-catenin expression and loss of membranous E-cadherin were independently associated with higher N stage (P = 0.03 and < 0.0001), vascular invasion (P < 0.01 and < 0.001) and worse survival (P < 0.01 and < 0.001). Additionally, there was an association between loss of membranous E-cadherin and higher T stage (P = 0.03). In MLH1- CRC, loss of membranous E-cadherin was associated with higher N stage (P = 0.05) and worse survival (P = 0.03). In presumed HNPCC CRC nuclear beta-catenin and membranous E-cadherin were not associated with tumour progression or worse survival. In all CRC subsets loss of cytoplasmic APC was not associated with clinicopathological features. Increasing nuclear beta-catenin expression and loss of membranous E-cadherin are independent, adverse prognostic factors in MMR-proficient and MLH1- CRC.