Frequent accumulation of nuclear E-cadherin and alterations in the Wnt signaling pathway in esophageal squamous cell carcinomas

Prediction of recurrence free survival for esophageal cancer patients using a protein signature based risk model

BACKGROUND

Biomarkers to predict the risk of disease recurrence in Esophageal squamous cell carcinoma (ESCC) patients are urgently needed to improve treatment. We developed proteins expression-based risk model to predict recurrence free survival for ESCC patients.

METHODS

Alterations in Wnt pathway components expression and subcellular localization were analyzed by immunohistochemistry in 80 ESCCs, 61 esophageal dysplastic and 47 normal tissues; correlated with clinicopathological parameters and clinical outcome over 86 months by survival analysis. Significant prognostic factors were identified by multivariable Cox regression analysis.

RESULTS

Biomarker signature score based on cytoplasmic β-catenin, nuclear c-Myc, nuclear DVL and membrane α-catenin was associated with recurrence free survival [Hazard ratio = 1.11 (95% CI = 1.05, 1.17), p < 0.001, C-index = 0.68] and added significant prognostic value over clinical parameters (p < 0.001). The inclusion of Slug further improved prognostic utility (p < 0.001, C-index = 0.71). Biomarker Signature Scoreslug improved risk classification abilities for clinical outcomes at 3 years, accurately predicting recurrence in 79% patients in 1 year and 97% in 3 years in high risk group; 73% patients within low risk group did not have recurrence in 1 year, with AUC of 0.76.

CONCLUSIONS

Our comprehensive risk model predictive for recurrence allowed us to determine the robustness of our biomarker panel in stratification of ESCC patients at high or low risk of disease recurrence; high risk patients are stratified for more rigorous personalized treatment while the low risk patients may be spared from harmful side effects of toxic therapy.

Distribution of E- and N-cadherin in subgroups of non-functioning pituitary neuroendocrine tumours

PURPOSE

Clinically non-functioning pituitary neuroendocrine tumours (NF-PitNETs) present a varying degree of aggressiveness, and reliable prognostic markers are lacking. We aimed to characterise the distribution of E- and N-cadherin in corticotroph, PIT1 and null-cell NF-PitNETs, and link it to the course of the tumours.

METHODS

The distribution of E- and N-cadherin was investigated by immunohistochemistry in a retrospective cohort of 30 tumours of the less common NF-PitNETs (corticotroph (N = 18), PIT1 (N = 8) and null-cell PitNETs (N = 4)). Immunoreactive scores (IRS) were compared to previously presented cohorts of gonadotroph NF-PitNETs (N = 105) and corticotroph functioning PitNETs (N = 17).

RESULTS

We found a low IRS for the extra-cellular domain of E-cadherin (median 0 (IQR 0-0, N = 135)), a medium to high IRS for the intra-cellular domain of E-cadherin (median 6 (IQR 4-9)) and a high IRS for N-cadherin (median 12 (IQR 10.5-12)) throughout the cohort of NF-PitNETs. The corticotroph NF-PitNETs presented a higher IRS for both the extra- and intra-cellular domain of E-cadherin (median 0 (IQR 0-1) and median 9 (IQR 6-12), respectively) than the gonadotroph NF-PitNETs (p < 0.001 for both comparisons). Presence of nuclear E-cadherin was associated with a weaker staining for the intra-cellular domain of E-cadherin (median 4 (IQR 0.5-6) and median 9 (IQR 9-12), for tumours with and without nuclear E-cadherin, respectively), and with a lower rate of re-intervention (p = 0.03).

CONCLUSIONS

Considering our results and the benign course of NF-PitNETs, we suggest that a high N-cadherin and downregulation of membranous E-cadherin are not associated with a more aggressive tumour behaviour in these subgroups of NF-PitNETs.

Expanded Basal Compartment and Disrupted Barrier in Vocal Fold Epithelium Infected with Mouse Papillomavirus MmuPV1

Laryngeal infection with low-risk human papillomaviruses can cause recurrent respiratory papillomatosis (RRP), a disease with severe effects on vocal fold epithelium resulting in impaired voice function and communication. RRP research has been stymied by limited preclinical models. We recently reported a murine model of laryngeal MmuPV1 infection and disease in immunodeficient mice. In the current study, we compare quantitative and qualitative measures of epithelial proliferation, apoptosis, differentiation, and barrier between mice with MmuPV1-induced disease of the larynx and surrounding tissues and equal numbers of uninfected controls. Findings supported our hypothesis that laryngeal MmuPV1 infection recapitulates many features of RRP. Like RRP, MmuPV1 increased proliferation in infected vocal fold epithelium, expanded the basal compartment of cells, decreased differentiated cells, and altered cell–cell junctions and basement membrane. Effects of MmuPV1 on apoptosis were equivocal, as with RRP. Barrier markers resembled human neoplastic disease in severe MmuPV1-induced disease. We conclude that MmuPV1 infection of the mouse larynx provides a useful, if imperfect, preclinical model for RRP that will facilitate further study and treatment development for this intractable and devastating disease.

The Expression of Tripartite Motif Protein 36 and β-Catenin Correlates with the Prognosis of Esophageal Cancer

Aims

Tripartite motif protein 36 (TRIM36) plays a tumor-suppressive role in prostate cancer. However, there is little information on the clinical relevance of TRIM36 expression in esophageal cancer (ESCA).

Methods

TRIM36 expression was analyzed by using The Cancer Genome Atlas (TCGA) ESCA dataset as well as by quantitative real-time polymerase chain reaction (PCR) and immunohistochemical (IHC) staining on samples from our hospital.

Results

In the current study, the analysis of TCGA ESCA dataset suggested the decreased expression of TRIM36 in ESCA tissues. Further analyses on samples from our hospital demonstrated that TRIM36 was significantly downregulated in ESCA tissues than in the noncancerous controls at both the mRNA and protein levels. Moreover, gene set enrichment analysis on TCGA ESCA dataset suggested that TRIM36 expression was inversely correlated with the β-catenin pathway. IHC staining data showed that 66.25% (53/80) and 51.25% (41/80) of ESCA cases had a low expression of TRIM36 and a high expression of β-catenin, respectively. By Fisher's exact test, we found that TRIM36 protein expression was significantly correlated with tumor size (P = 0.0104), tumor stage (P = 0.0169), lymph node metastasis (P = 0.0021), vital status (P = 0.0443), and β-catenin expression (P = 0.0329). These findings suggest the potential clinical significance of TRIM36 in ESCA. Kaplan–Meier and log-rank test demonstrated that a low expression of TRIM6 and a high expression of β-catenin were associated with poor overall survival of ESCA patients.

Conclusions

Our study provides evidence for the prognostic value of TRIM36 in ESCA.

FSH Levels Are Related to E-cadherin Expression and Subcellular Location in Nonfunctioning Pituitary Tumors

CONTEXT

Gonadotroph pituitary neuroendocrine tumors (PitNETs) can express follicle-stimulating hormone (FSH) and luteinizing hormone (LH) or be hormone negative, but they rarely secrete hormones. During tumor development, epithelial cells develop a mesenchymal phenotype. This process is characterized by decreased membranous E-cadherin and translocation of E-cadherin to the nucleus. Estrogen receptors (ERs) regulate both E-cadherin and FSH expression and secretion. Whether the hormone status of patients with gonadotroph PitNETs is regulated by epithelial-to-mesenchymal transition (EMT) and ERs is unknown.

OBJECTIVES

To study the effect of EMT on hormone expression in gonadotroph nonfunctioning (NF)-PitNETs.

DESIGN

Molecular and clinical analyses of 105 gonadotroph PitNETs. Immunohistochemical studies and real-time quantitative polymerase chain reaction were performed for FSH, LH, E-cadherin, and ERα. Further analyses included blood samples, clinical data, and radiological images.

SETTING

All patients were operated on in the same tertiary referral center.

RESULTS

NF-PitNET with high FSH expression had decreased immunohistochemical staining for membranous E-cadherin (P < .0001) and increased staining for nuclear E-cadherin (P < .0001). Furthermore, high FSH expression was associated with increased ERα staining (P = .0002) and ERα mRNA (P = .0039). Circulating levels of plasma-FSH (P-FSH) correlated with FSH staining in gonadotroph NF-PitNET (P = .0025). Tumor size and invasiveness was not related to FSH staining, E-cadherin, or ERα. LH expression was not associated with E-cadherin or ERα.

CONCLUSION

In gonadotroph PitNETs, FSH staining is related to E-cadherin, ERα expression, and circulating levels of P-FSH. There was no association between FSH staining and invasiveness. The clinical significance of these findings will be investigated in ongoing prospective studies.

Characterization of a five-microRNA signature as a prognostic biomarker for esophageal squamous cell carcinoma

This study aims to identify a miRNAs signature for predicting overall survival (OS) in esophageal squamous cell carcinoma (ESCC) patients. MiRNA expression profiles and corresponding clinical information of 119 ESCC patients were obtained from NCBI GEO and used as the training set. Differentially expressed miRNAs (DEmiRNAs) were screened between early-stage and late-stage samples. Cox regression analysis, recursive feature elimination (RFE)-support vector machine (SVM) algorithm, and LASSO Cox regression model were used to identify prognostic miRNAs and consequently build a prognostic scoring model. Moreover, promising target genes of these prognostic miRNAs were predicted followed by construction of miRNA-target gene networks. Functional relevance of predicted target genes of these prognostic miRNAs in ESCC was analyzed by performing function enrichment analyses. There were 46 DEmiRNAs between early-stage and late-stage samples in the training set. A risk score model based on five miRNAs was built. The five-miRNA risk score could classify the training set into a high-risk group and a low-risk group with significantly different OS time. Risk stratification ability of the five-miRNA risk score was successfully validated on an independent set from the Cancer Genome Atlas (TCGA). Various biological processes and pathways were identified to be related to these miRNAs, such as Wnt signaling pathway, inflammatory mediator regulation of TRP channels pathway, and estrogen signaling pathway. The present study suggests a pathological stage-related five-miRNA signature that may have clinical implications in predicting prognosis of ESCC patients.

E-cadherin clone 36 nuclear staining dictates adverse disease outcome in lobular breast cancer patients

Breast cancer is a heterogeneous disease and additional biomarkers for individually predicting patient outcomes are needed. Aberrant membrane E-cadherin immunoexpression has been demonstrated in lobular breast cancer. Also, E-cadherin nuclear staining has been reported, associating with prognosis in various tumors. Here, we explore whether membrane or nuclear staining of E-cadherin has the potential to dictate prognosis of patients with lobular breast cancer. We selected a cohort of 285 consecutively diagnosed lobular breast cancer patients and performed immunohistochemistry for E-cadherin (clones 36, EP700Y, and NCH38) and P-cadherin (clone 56C1) in representative formalin-fixed paraffin-embedded blocks. All patients were female, HER2-negative and surgically treated in a single institution. Survival curves were computed by Kaplan-Meier analysis. Hazard ratios and respective 95% confidence intervals were estimated using Cox regression models. Statistical significance was set at p < 0.05. Nuclear staining for E-cadherin clone 36 was frequent (35%), contrarily to other antibodies tested. Negative correlation was found between nuclear and membrane E-cadherin clone 36 immunostaining (r_s = -0.30, p < 0.001), whereas positive correlation was found between membrane immunoexpression of E-cadherin clone 36 and P-cadherin (r_s = 0.31, p < 0.001). Patients with any evidence of E-cadherin clone 36 nuclear immunostaining disclosed significantly worse overall survival, disease-specific-survival and disease/progression-free survival (hazard ratio = 2.059, 95% confidence interval 1.313-3.230; hazard ratio = 1.980, 95% confidence interval 1.121-3.495; and hazard ratio = 2.341, 95% confidence interval 1.403-3.905, respectively). Differences in survival were more remarkable when considering nuclear E-cadherin immunoexpression in ≥50% tumor cells. Poorer survival was maintained in multivariable analysis, after adjusting for age, menopausal and PR status, treatment course, vascular invasion, tumor grade and stage. Our results support the use of antibodies against the cytoplasmic domain of E-cadherin, such as clone 36, which may reveal nuclear immunostaining and indicate more aggressive clinical course in patients with lobular breast cancer. We hypothesize that E-cadherin is cleaved and translocated to nucleus functioning as transcription factor.

Qiyusanlong decoction suppresses lung cancer in mice via Wnt/β-catenin pathway

Lung cancer is one of the most fatal cancers due to its high metastatic rate. Traditional Chinese medicine has been used in cancer patients for decades to improve quality of life and prolong survival time. The present study used a novel Qiyusanlong (QYSL) decoction composed of 10 kinds of Chinese medicine including astragalus membranaceus (Huangqi), polygonatumod oratum (yuzu), scolopendra (tianlong), pberetima (dilong), solanum nigrum (longkui), herbahedyotis (baihushecao), semen coicis (yiyiren), euphorbia helioscopia (zeqi), curcuma longa (eshu) and tendril-leaved fritillary bulb (chuanbei). The effects and function of the QYSL decoction remain to be elucidated. The present study established a mouse xenograft model using Lewis lung carcinoma cell injection and administered different doses of QYSL decoction to the mice. It was demonstrated that the chemotherapy drug Cisplatin (DDP) and QYSL decoction repressed lung tumor growth, and the inhibitory effect of DDP was more significant. Furthermore, QYSL decoction and DDP modulated the expression of regulatory proteins in the Wnt/β‑catenin pathway, including Wnt1, Wnt2, Wnt5a and glycogen synthase kinase 3β, detected by western blotting, and affected the signals of cluster of differentiation 44 variation 6 and Survivin in tumor tissues, examined via immunohistochemistry. The combination of QYSL decoction and DDP enhanced the inhibitory effect. These data demonstrated that the QYSL decoction repressed lung tumor development via the Wnt/β‑catenin pathway. The therapeutic effect of QYSL decoction alone was milder compared with DDP, however the combination of QYSL decoction and chemotherapy exhibited an increased the rapeutic effect compared with the treatments administered alone. These findings revealed the function of QYSL decoction as a lung cancer treatment and provided insight for a novel lung cancer therapy.

Complex Determinants of Epithelial: Mesenchymal Phenotypic Plasticity in Ovarian Cancer

Unlike most epithelial malignancies which metastasize hematogenously, metastasis of epithelial ovarian cancer (EOC) occurs primarily via transcoelomic dissemination, characterized by exfoliation of cells from the primary tumor, avoidance of detachment-induced cell death (anoikis), movement throughout the peritoneal cavity as individual cells and multi-cellular aggregates (MCAs), adhesion to and disruption of the mesothelial lining of the peritoneum, and submesothelial matrix anchoring and proliferation to generate widely disseminated metastases. This exceptional microenvironment is highly permissive for phenotypic plasticity, enabling mesenchymal-to-epithelial (MET) and epithelial-to-mesenchymal (EMT) transitions. In this review, we summarize current knowledge on EOC heterogeneity in an EMT context, outline major regulators of EMT in ovarian cancer, address controversies in EMT and EOC chemoresistance, and highlight computational modeling approaches toward understanding EMT/MET in EOC.

Black raspberries demethylate Sfrp4, a WNT pathway antagonist, in rat esophageal squamous cell papilloma

Aberrant methylation of DNA is a common event in the development of cancers, including squamous cell carcinoma (SCC) of the human esophagus. In the present study, we determined: (a) whether aberrant DNA methylation also occurs in the development of N-nitrosomethylbenzylamine (NMBA)-induced tumorigenesis in the rat esophagus, a model of human esophageal SCC; and (b) if so, whether dietary black raspberries (BRBs) are capable of preventing this aberrant DNA methylation. A diet containing 5% BRBs inhibited the development of NMBA-induced tumors in the rat esophagus. This inhibition was associated with reduced mRNA levels of the DNA methyltransferases, Dnmt1 and Dnmt3b, in both dysplastic lesions and in papillomas of the esophagus. In addition, promoter methylation of Sfrp4, a WNT pathway antagonist, was significantly reduced by the berry diet, and this was associated with decreased nuclear localization of β-CATENIN and reduced expression of c-MYC protein in NMBA-treated esophagi. Decreased promoter methylation of Sfrp4 correlated with decreased expression of Dmnt3b and, ultimately, with increased Sfrp4 mRNA expression. This suggests that epigenetic alterations in NMBA-induced rat esophageal tumorigenesis recapitulate epigenetic events in human esophageal SCC, and that BRBs could be useful in preventing the aberrant DNA methylation involved in the development of human esophageal SCC. © 2015 Wiley Periodicals, Inc.

Vascular disruptive agent OXi4503 and anti-angiogenic agent Sunitinib combination treatment prolong survival of mice with CRC liver metastasis

Background

Preclinical research indicate that vascular disrupting agent (VDA) treatment induces extensive tumor death but also a systemic mobilization of bone marrow derived cells including endothelial progenitor cells (EPC) leading to revascularization and renewed growth within the residual tumor. This study investigates if combination of VDA with the anti-angiogenic agent Sunitinib increases the treatment efficacy in a colorectal liver metastases mouse model.

Methods

CBA mice with established liver metastases were given a single dose of OXi4503 at day 16 post tumor induction, a daily dose of Sunitinib starting at day 14 or day 16 post tumor induction or a combination of Sunitinib given daily from day 14 or day 16 post tumor induction in combination with a single dose of OXi4503 at day 16. Treatment was terminated at day 21 post tumor induction and its effects were assessed using stereological and immunohistochemical techniques. Long term effects were assessed in a survival study.

Results

Combination with long (7 day) Sunitinib treatment lead to liver toxicity but this was ameliorated in the shorter (5 day) treatment without significantly altering the effects on tumor reduction. Combination treatment resulted in significant reduction of viable tumor, reduction in tumor vasculature, reduction in tumor proliferation, increase in tumor apoptosis and prolonged mouse survival compared to control and single arm treatments. Complete tumor eradication was not achieved. Redistribution of E-cadherin and strong up regulation of ZEB1 and Vimentin were observed in the surviving tumor; indicative of epithelial to mesenchymal transition (EMT), a mechanism that could contribute to tumor resistance.

Conclusions

Combination treatment significantly reduces viable tumor and prolongs animal survival. EMT in the surviving tumor may prevent total tumor eradication and could provide novel targets for a more lasting treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2568-7) contains supplementary material, which is available to authorized users.

The role of biological markers of epithelial to mesenchymal transition in oesophageal adenocarcinoma, an immunohistochemical study

BACKGROUND

E-cadherin, β-catenin, epidermal growth factor receptor (EGFR), neuronal cadherin (N-cadherin) and Cyclin D1 are involved in epithelial to mesenchymal transition (EMT). However, the prognostic significance of EMT markers in oesophageal adenocarcinoma (OAC) is unknown. Aim of this study was to evaluate the prognostic value of, and the association between different EMT markers in OAC.

METHODS

Tumour cores of 154 patients with OAC were included in a tissue microarray. Scoring criteria was based on immunohistochemical staining intensity.

RESULTS

EMT-associated markers were expressed in OAC: reduced membranous E-cadherin and β-catenin were seen in 11.4% and 51.7%, nuclear β-catenin in 19.1% and EGFR and Cyclin D1 overexpression in 56.5% and 27.4% of tumours. Mesenchymal marker N-cadherin was not expressed in OAC. A positive correlation was seen between membranous β-catenin and E-cadherin expression (R=0.209, p=0.001) and between EGFR and Cyclin D1 (R=0.257, p=0.002). In univariate analysis, EGFR overexpression and membranous β-catenin staining were significantly associated with a poor survival (HR 2.145; 95% CI 1.429 to 3.218, p<0.001 and HR 1.665; 95% CI 1.114 to 2.488; p=0.013). However, Cyclin D1 (HR 1.092; 95% CI 0.702 to 1.698; p=0.697), nuclear β-catenin (HR 1.322; 95% CI 0.799 to 2.189; p=0.277) and E-cadherin (HR 1.012; 95% CI 0.554 to 1.851; p=0.968) were not associated with survival. In multivariate analysis, EGFR overexpression was an independent prognostic factor for poor survival (HR 1.678; 95% CI 1.055 to 2.668; p=0.029) together with T stage (HR 2.759; 95% CI 1.356 to 5.576; p=0.005).

CONCLUSIONS

This study supports the presence of EMT in OAC. Moreover, EGFR overexpression was independently associated with a poor survival.

Establishment of human patient-derived endometrial cancer xenografts in NOD scid gamma mice for the study of invasion and metastasis

Objective

Most endometrial cancers are detected early and have a good prognosis, while some endometrial cancers are highly invasive, metastasize early, and respond suboptimally to therapy. Currently, appropriate model systems to study the aggressive nature of these tumors are lacking. The objective of this study was to establish a mouse xenograft model of endometrial tumors derived from patients in order to study the biological aggressive characteristics that underlie invasion and metastasis.

Methods

Endometrial tumor tissue fragments (1.5 mm×1.5 mm) from patients undergoing surgery, were transplanted under the renal capsule of NOD scid gamma mice. After 6–8 weeks, tumors were excised and serially transplanted into additional mice for propagation. Immunohistochemical analysis of the tumors was done for various tumor markers.

Results

Four cases of different subtypes of endometrial cancer were grown and propagated in mice. Three of the four tumor cases invaded into the kidneys and to adjacent organs. While all tumors exhibited minimal to no staining for estrogen receptor α, progesterone receptor staining was observed for tumor grafts. In addition, levels and localization of E-cadherin, cytokeratin and vimentin varied depending on subtype. Finally, all tumor xenografts stained positively for urokinase plasminogen activator while 3 tumor xenografts, which showed invasive characteristics, stained positively for urokinase plasminogen activator receptor.

Conclusion

Endometrial tumors transplanted under the renal capsule exhibit growth, invasion and local spread. These tumors can be propagated and used to study aggressive endometrial cancer.

Expression profile of microRNA-200 family in hepatocellular carcinoma with bile duct tumor thrombus

OBJECTIVE

The aim of this study was to assess the role of the miR-200 family in the pathogenesis of hepatocellular carcinoma with bile duct tumor thrombus (HCC-BDTT).

BACKGROUND

Hepatocellular carcinoma with bile duct tumor thrombus is a challenging condition because of its rarity and dismal prognosis. Epithelial-to-mesenchymal transition (EMT) is considered a critical step in the progression and metastasis of HCC and is regulated by the microRNA-200 (miR-200) family.

METHODS

Thirty patients with HCC-BDTT were enrolled and 1240 patients with conventional HCC (cHCC) served as clinicopathologic controls. Sixty age- and sex-matched cHCC patients were selected to compare the miR-200 family expression profile and immunohistochemical characteristics. Gain- and loss-of-function studies of the miR-200 family were conducted using the hepatoma cell lines.

RESULTS

Although the mean size of HCC-BDTT was smaller than that of cHCC, the former had a higher incidence of vascular invasion and a poorer long-term survival. The expressions of miR-200c and miR-141 were downregulated in HCC-BDTT (4.5- and 4.8-fold decrease, respectively). Downregulation of both miR-200c and miR-141 independently predicted disease-free survival. The HCC-BDTT, but not cHCC, exhibited overexpression of ZEB1, Twist, transforming growth factor-β receptor type II, and vimentin, and aberrant E-cadherin expression, indicating EMT. The HCC-BDTT demonstrated increased expression in IL-6 and stemness factor Bmi1, but reduced level of metastasis-suppressive protein, insulin-like growth factor-binding protein 4. The invasive ability of the highly aggressive Mahlavu cell was attenuated by pre-miR-200c+141, whereas the invasive ability of the less aggressive Huh7 cell was enhanced by anti-miR-200c+141.

CONCLUSIONS

Simultaneous silencing of miR-200c and miR-141 was likely to be responsible for the development of HCC-BDTT via ZEB1-directed EMT activation and Sec23a-mediated secretome.

Distinct genetic aberrations in oesophageal adeno and squamous carcinoma

BACKGROUND

The two main oesophageal cancer subtypes namely adenocarcinoma and squamous cell carcinoma exhibit interesting clinical, pathological and geographical variations with the former being more common in the West and the latter in Asia.

MATERIALS AND METHODS

We evaluated status of p53, EGFR, Wnt and HPV in addition to microsatellite instability and loss of heterozygosity of several chromosomal loci in the two oesophageal cancer subtypes from India. The comparative analysis was extended to two oesophageal adenosquamous mixed cancer samples.

RESULTS

Our results reveal a high frequency of EGFR overexpression in ESCC as against EAC, while Wnt activation was a significantly more common event in EAC as against ESCC. Frequencies of p53 perturbations were not significantly different in the two subtypes. Interestingly, the EGFR and Wnt status in adenocarcinoma and squamous components of the two oesophageal adenosquamous cancer samples were identical to primary tumours. In addition, no common molecular aberration (including instability and loss of heterozygosity) in several microsatellites was detected in DNA isolated from the two components in both adenosquamous cancer samples.

CONCLUSIONS

Our results reveal the presence of distinct aberrations in oesophageal adenocarcinoma and squamous cell carcinoma which are replicated in the respective components of adenosquamous cancers. The study therefore suggests perhaps an independent origin of the two components of oesophageal adenosquamous mixed cancer.

Epithelial to mesenchymal transition markers are associated with an increased metastatic risk in primary cutaneous squamous cell carcinomas but are attenuated in lymph node metastases

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) is the second most common malignancy in humans and approximately 5% metastasize, usually to regional lymph nodes. Epithelial to mesenchymal transition (EMT) is a process involving loss of intercellular adhesion, acquisition of a mesenchymal phenotype and enhanced migratory potential; epithelial markers, such as E-cadherin, are down-regulated and mesenchymal proteins (Vimentin), increased.

OBJECTIVE

To investigate the expression of EMT markers in metastatic SCC (MSCC) and their corresponding metastases, and to correlate them with clinico-pathological factors associated with an increased risk of metastasis.

METHODS

We performed a retrospective study that included 146 cSCC samples (51 primary non-metastatic, 56 primary metastatic, 39 lymphatic metastases). Immunohistochemistry for E-cadherin, Vimentin, Snail, beta-catenin, Twist, Zeb1 and Podoplanin was performed.

RESULTS

Loss of membranous E-cadherin was observed in 77% cSCCs, with no differences between MSCC and non-MSCC. Among the transcriptional factors controlling EMT, no significant Snail1 expression was detected. Twist, Zeb1, Vimentin, beta-catenin and Podoplanin were significantly overexpressed in MSCCs. Twist ectopic expression in SCC13 cells induced Zeb1, Vimentin and Podoplanin expression and E-cadherin delocalization. These changes resulted in a scattered migration pattern in vitro. Expression of EMT markers was decreased in the metastases when compared with the corresponding primary tumors.

CONCLUSION

These results suggest that a partial EMT, characterized by the expression of Twist but without a total E-cadherin depletion, is involved in the acquisition of invasive traits by cSCC, but the process is downregulated in lymph node metastases.

Advances in research of signaling pathways associated with cancer stem cells in esophageal squamous cell carcinoma

The discovery of cancer stem cells has led to a better understanding of mechanisms underlying the occurrence, development and metastasis of cancer. Three signaling pathways, Wnt, PIP3, and Hedgehog, play an important role in self-renewal and differentiation of stem cells. Once abnormalities occur in these signaling pathways, cancer stem cells will present aberrant differentiation and unlimited proliferation and eventually develop into tumors. Although there is still controversy over the existence of stem cells in esophageal squamous cell carcinoma (ESCC), more and more evidence suggests that the above three signaling pathways are important in promoting the differentiation of esophageal epithelial cells, accelerating the progression of ESCC and causing radiotherapy and chemotherapy resistance.

Disseminated breast cancer cells acquire a highly malignant and aggressive metastatic phenotype during metastatic latency in the bone

Background

Disseminated tumor cells (DTCs) in the bone marrow may exist in a dormant state for extended periods of time, maintaining the ability to proliferate upon activation, engraft at new sites, and form detectable metastases. However, understanding of the behavior and biology of dormant breast cancer cells in the bone marrow niche remains limited, as well as their potential involvement in tumor recurrence and metastasis. Therefore, the purpose of this study was to investigate the tumorigenicity and metastatic potential of dormant disseminated breast cancer cells (prior to activation) in the bone marrow.

Methodology/Principal Findings

Total bone marrow, isolated from mice previously injected with tumorspheres into the mammary fat pad, was injected into the mammary fat pad of NUDE mice. As a negative control, bone marrow isolated from non-injected mice was injected into the mammary fat pad of NUDE mice. The resultant tumors were analyzed by immunohistochemistry for expression of epithelial and mesenchymal markers. Mouse lungs, livers, and kidneys were analyzed by H+E staining to detect metastases. The injection of bone marrow isolated from mice previously injected with tumorspheres into the mammary fat pad, resulted in large tumor formation in the mammary fat pad 2 months post-injection. However, the injection of bone marrow isolated from non-injected mice did not result in tumor formation in the mammary fat pad. The DTC-derived tumors exhibited accelerated development of metastatic lesions within the lung, liver and kidney. The resultant tumors and the majority of metastatic lesions within the lung and liver exhibited a mesenchymal-like phenotype.

Conclusions/Significance

Dormant DTCs within the bone marrow are highly malignant upon injection into the mammary fat pad, with the accelerated development of metastatic lesions within the lung, liver and kidney. These results suggest the acquisition of a more aggressive phenotype of DTCs during metastatic latency within the bone marrow microenvironment.

Primary bladder adenocarcinoma versus metastatic colorectal adenocarcinoma: a persisting diagnostic challenge

Aim

This study attempted to distinguish primary bladder adenocarcinoma (PBA) from metastatic colonic adenocarcinomas (MCA), which is a difficult diagnostic and clinical problem.

Methods

Twenty-four cases of bladder adenocarcinomas (12 primary & 12 metastatic colorectal) were included in the study with urothelial carcinoma (UC) and colonic adenocarcinoma (CA) as controls. A panel of immunohistochemical (IHC) stains along with fluorescence in-situ hybridization (FISH), using the UroVysion probe set, was performed.

Results

The majority of the PBAs presented with advanced disease. Enteric histologic subtype was the most common morphological variant. Strong nuclear with cytoplasmic-membranous staining of β-catenin was seen in 75% of MCA and only 16.7% PBA (<10% staining cells). Although abnormal nuclear staining with E-cadherin was seen in both PBA and MCA, it was more frequent in former. CK-7, CK-20, villin and CDX-2 stains were not helpful in distinguishing the two entities. FISH did not reveal any unique differences in chromosomal abnormality between the two groups.

Conclusion

Although there was a statistically significant difference in β-catenin and E-cadherin staining between two groups, we did not find any IHC or FISH marker that was specific for PBA. Distinction between PBA and MCA remains a diagnostic problem and clinical correlation is vital before rendering a diagnosis.

Virtual slides

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1393156268152357

Deguelin suppresses pancreatic tumor growth and metastasis by inhibiting epithelial-to-mesenchymal transition in an orthotopic model

Deguelin is known to suppress the growth of cancer cells; however, its anti-metastatic effects have not been studied so far in any cancer model. In the present study, we aimed to evaluate the anti-metastatic potential of deguelin in vivo and in tumor growth factor-β1 (TGFβ1)-stimulated cells. Our results demonstrate that tumor growth, peritoneal dissemination and liver/lung metastasis of orthotopically implanted PanC-1-luc cells were significantly reduced in deguelin-treated mice along with the induction of apoptosis. Furthermore, deguelin-treated tumors showed increased epithelial signature such as increased expression of E-Cadherin and cytokeratin-18 and decreased expression of Snail. Similar observations were made when PanC-1, COLO-357 and L3.6pl cells were treated in vitro with deguelin. Moreover, E-cadherin was transcriptionally upregulated and accumulated in the membrane fraction of deguelin-treated cells, as indicated by increased interaction of E-Cadherin with β-catenin. TGFβ1-induced downregulation of E-Cadherin and upregulation of Snail were abrogated by deguelin treatment. In addition, deguelin inhibited TGFβ1-induced Smad3 phosphorylation and Smad4 nuclear translocation in PanC-1 cells. Furthermore, when TGFβ1-induced nuclear factor kappa B (NFκB) activation was inhibited, TGFβ1-induced Snail upregulation or E-Cadherin downregulation was blocked. Deguelin also significantly downregulated the constitutive phosphorylation and DNA binding of NFκB in a dose-dependent manner. Interestingly, overexpression of either NFκB or Snail completely abrogated deguelin-mediated epithelial-to-mesenchymal transition (EMT) inhibition, whereas overexpression of NFκB but not Snail rescued cells from deguelin-induced apoptosis. Hence, deguelin targets NFκB to induce reversal of EMT and apoptosis but downstream effectors might be different for both processes. Taken together, our results suggest that deguelin suppresses both pancreatic tumor growth and metastasis by inducing apoptosis and inhibiting EMT.

Inhibition of SOX17 by microRNA 141 and methylation activates the WNT signaling pathway in esophageal cancer

In this study, we explored the possibility of SOX17 promoter region methylation as an esophageal cancer detection marker, the regulation of SOX17 expression, and the function of SOX17 in the WNT signaling pathway in esophageal cancer. Eight esophageal cancer cell lines, 9 normal esophageal mucosa samples, 60 cases of dysplasia, and 169 cancer tissue samples were included. Methylation-specific PCR, semiquantitative reverse transcription-PCR, immunohistochemistry, luciferase reporter assay, colony formation, and Western blot analysis were used to analyze methylation and function of SOX17 in esophageal cancer. MicroRNA-related detection methods were performed to evaluate microRNA regulation of SOX17. SOX17 methylation was found in progression tendency with 0% of normal mucosa, 39% of grade 1 dysplasia, 48% of grades 2 and 3 dysplasia, and 65% of primary cancer. SOX17 methylation is related to esophageal cancer patients' history of alcohol use and may induce β-catenin expression and redistribution. Loss of SOX17 expression is correlated to promoter region hypermethylation, and re-expression was activated by 5-aza-2'-deoxycytidine treatment in esophageal cancer cell lines. Restoration of SOX17 expression suppresses TCF/β-catenin-dependent transcription and colony formation. MicroRNA 141 was also found to down-regulate SOX17 expression and activate the WNT signal pathway. SOX17 is frequently methylated in esophageal cancer and in a progression tendency during esophageal carcinogenesis. Loss of SOX17 removes the normal inhibition of WNT signaling and promotes esophageal tumorigenesis.

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.

E-cadherin's dark side: possible role in tumor progression

In the context of cancer, E-cadherin has traditionally been categorized as a tumor suppressor, given its essential role in the formation of proper intercellular junctions, and its downregulation in the process of epithelial-mesenchymal transition (EMT) in epithelial tumor progression. Germline or somatic mutations in the E-cadherin gene (CDH1) or downregulation by epigenetic mechanisms have been described in a small subset of epithelial cancers. However, recent evidence also points toward a promoting role of E-cadherin in several aspects of tumor progression. This includes preserved (or increased) E-cadherin expression in microemboli of inflammatory breast carcinoma, a possible "mesenchymal to epithelial transition" (MET) in ovarian carcinoma, collective cell invasion in some epithelial cancers, a recent association of E-cadherin expression with a more aggressive brain tumor subset, as well as the intriguing possibility of E-cadherin involvement in specific signaling networks in the cytoplasm and/or nucleus. In this review we address a lesser-known, positive role for E-cadherin in cancer.

S100A4 silencing blocks invasive ability of esophageal squamous cell carcinoma cells

AIM: To investigate a potential role of S100A4 in esophagus squamous cell carcinoma metastasis (ESCCs).

METHODS: Expression of S100A4 and E-cadherin were analyzed in frozen sections from ESCCs (metastasis, n = 28; non-metastasis, n = 20) by reverse transcription-polymerase chain reaction, quantitative polymerase chain reaction and immunohistochemistry. To explore the influence of S100A4 on esophageal cancer invasion and metastasis, S100A4 was overexpressed or silenced by S100A4 siRNA in TE-13 or Eca-109 cells in vitro and in vivo.

RESULTS: We found the mRNA and protein levels of S100A4 expression in ESCCs was significantly upregulated, and more importantly, that expression of S100A4 and E cadherin are strongly negatively correlated in patients who had metastasis. It was indicated that overexpression of S100A4 in TE-13 and Eca-109 cells downregulates the expression of E-cadherin, leading to increased cell migration in vitro, whereas knockdown of S100A4 inhibited cell migration and upregulation of E-cadherin expression. Moreover, the loss of cell metastatic potential was rescued by overexpression of E-cadherin completely. In addition, nude mice inoculated with S100A4 siRNA-transfected cells exhibited a significantly decreased invasion ability in vivo.

CONCLUSION: S100A4 may be involved in ESCC progression by regulate E-cadherin expression, vector-based RNA interference targeting S100A4 is a potential therapeutic method for human ESCC.

Advances in research of interaction between hepatitis C virus nonstructural proteins and host proteins

Hepatitis C virus (HCV) is another common cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma after hepatitis B virus (HBV). Up to now, the mechanisms by which HCV promotes persistent infection and cancer remain unclear, and there are neither effective drugs nor vaccines against HCV available. Interaction between virus proteins and host proteins is a hot topic in research of the pathogenesis of viral hepatitis. Recent research shows that interaction between HCV nonstructural proteins and host proteins has an important impact on viral replication, carcinogenesis, interferon resistance, and disorders of glycometabolism and lipid metabolism. This paper summarizes the recent advances in research of interaction between HCV nonstructural proteins and host proteins.

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

AIMS

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).

METHODS AND RESULTS

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.

CONCLUSIONS

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.

Intestine-specific transcription factor Cdx2 induces E-cadherin function by enhancing the trafficking of E-cadherin to the cell membrane

Cdx2 is an intestine-specific transcription factor required for normal intestinal epithelium development. Cdx2 regulates the expression of intestine-specific genes and induces cell adhesion and columnar morphogenesis. Cdx2 also has tumor-suppressor properties, including the reduction of colon cancer cell proliferation and cell invasion, the latter due to its effects on cell adhesion. E-cadherin is a cell adhesion protein required for adherens junction formation and the establishment of intestinal cell polarity. The objective of this study was to elucidate the mechanism by which Cdx2 regulates E-cadherin function. Two colon cancer cell lines were identified in which Cdx2 expression was associated with increased cell-cell adhesion and diminished cell migration. In both cell lines, Cdx2 did not directly alter E-cadherin levels but increased its trafficking to the cell membrane compartment. Cdx2 enhanced this trafficking by altering receptor tyrosine kinase (RTK) activity. Cdx2 expression diminished phosphorylated Abl and phosphorylated Rac levels, which are downstream effectors of RTKs. Specific chemical inhibition or short interfering RNA (shRNA) knockdown of c-Abl kinase phenocopied Cdx2's cell-cell adhesion effects. In Colo 205 cells, Cdx2 reduced PDGF receptor and IGF-I receptor activation. This was mediated by caveolin-1, which was induced by Cdx2. Targeted shRNA knockdown of caveolin-1 restored PDGF receptor and reversed E-cadherin membrane trafficking, despite Cdx2 expression. We conclude that Cdx2 regulates E-cadherin function indirectly by disrupting RTK activity and enhancing E-cadherin trafficking to the cell membrane compartment. This novel mechanism advances Cdx2's prodifferentiation and antitumor properties and suggests that Cdx2 may broadly regulate RTK activity in normal intestinal epithelium by modulating membrane trafficking of proteins.

Site-dependent E-cadherin cleavage and nuclear translocation in a metastatic colorectal cancer model

Metastases are frequently found during colorectal cancer diagnoses and are the main determinants of clinical outcome. The lack of reliable models of metastases has precluded their mechanistic understanding and our capacity to improve outcome. We studied the effect of E-cadherin and Snail1 expression on metastagenesis in a colorectal cancer model. We microinjected SW480-ADH human colorectal cancer cells, transfected with an empty vector (Mock) or overexpressing Snail1 (Snail1(OE)) or E-cadherin (E-cadherin(OE)), in the ceca of nude mice (eight per group) and analyzed tumor growth, dissemination, and Snail1, E-cadherin, β-catenin, and Presenilin1 (PS1) expression in local tumors and/or metastatic foci. Snail1(OE) cells disseminated only to lymph nodes, whereas Mock or E-cadherin(OE) cells spread to lymph nodes and peritoneums. Peritoneal tumor foci developed by E-cadherin(OE) cells presented an increase in E-cadherin proteolysis and nuclear translocation, and enhanced expression of proteolytically active PS1, which was linked to increased tumor growth and shortened mouse survival. Interestingly, local and lymph node tumors in mice bearing E-cadherin(OE) cells overexpressed E-cadherin, but they did not show E-cadherin proteolysis or nuclear translocation. Remarkably, E-cadherin nuclear translocation and enhanced expression of active PS1 were found in a patient with colorectal signet-ring cell carcinoma. In conclusion, we have established a colorectal cancer metastasis model in which E-cadherin proteolyis and nuclear translocation associates with aggressive foci growth only in the peritoneal microenvironment.

The expression of E-cadherin in somatotroph pituitary adenomas is related to tumor size, invasiveness, and somatostatin analog response

CONTEXT

Appropriate cell-to-cell adhesion is fundamental for the epithelial phenotype of pituitary cells. Loss of the adhesion protein E-cadherin has been associated with invasiveness, metastasis, and poor prognosis in cancers of epithelial origin. In somatotroph adenomas, a variable and reduced expression of E-cadherin has been demonstrated. In addition, nuclear translocation of E-cadherin was found to correlate with pituitary tumor invasion.

OBJECTIVE

The objective was to examine the protein expression of E-cadherin in somatotroph pituitary adenomas in relation to adenoma size, invasiveness, and somatostatin analog (SMS) efficacy.

PATIENTS AND METHODS

Eighty-three patients were included, and 29 were treated preoperatively with SMS. Adenoma E-cadherin protein expression was analyzed by Western blot (61 patients) and immunohistochemistry (IHC) (80 patients) with antibodies directed against both extracellular and intracellular domains (IHC). The acute (direct surgery group) and long-term (preoperatively treated group) SMS responses were evaluated. Baseline tumor volume and invasiveness were measured on magnetic resonance imaging scans.

RESULTS

Membranous E-cadherin was lost in several adenomas. Nine of these were nuclear E-cadherin positive. The E-cadherin protein expression correlated negatively to tumor size and positively to acute SMS response. Low E-cadherin levels (preoperatively treated group only) and loss of membranous E-cadherin correlated to tumor invasiveness. The E-cadherin level correlated positively to tumor reduction after SMS treatment, and adenomas with nuclear E-cadherin staining had lower IGF-I reduction and tumor shrinkage. Preoperatively treated adenomas had reduced E-cadherin protein levels, but the IHC expression was unaltered.

CONCLUSION

Reduced E-cadherin expression may correlate to a dedifferentiated phenotype in the somatotroph pituitary adenomas.

Increased expression of Dsg2 in malignant skin carcinomas: A tissue-microarray based study

Desmoglein 2 (Dsg2), a transmembrane cadherin of the desmosomal cell-cell adhesion structure, is downregulated with epithelial differentiation. We recently demonstrated that overexpression of Dsg2 in epidermal keratinocytes deregulates multiple signaling pathways associated with increased growth rate, anchorage-independent cell survival, and the development of skin tumors. While changes in Dsg2 expression have been observed in neoplastic lesions, the correlation of expression levels and localization of Dsg2 and the state of tumor development has not been fully established. Here we generated a highly sensitive Dsg2 antibody (Ab10) and characterized that antibody along with a previously developed Dsg2 specific antibody 10D2. Using these antibodies in immunostaining of tissue microarrays, we show a dramatic upregulation of Dsg2 expression in certain human epithelial malignancies including basal cell carcinomas (BCC; n = 12), squamous cell carcinomas (SCC; n = 57), carcinomas of sebaceous and sweat glands (n = 12), and adenocarcinomas (n = 3). Dsg2 expression was completely absent in malignant fibrosarcomas (n = 16) and melanomas (n = 15). While Dsg2 expression was consistently strong in BCC, it varied in SCC with a minor correlation between a decrease of Dsg2 expression and tumor differentiation. In summary, we have identified Dsg2 as a potential novel marker for epithelial-derived malignancies.

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.

Revision 2: an immunohistochemical approach and evaluation of solid pseudopapillary tumour of the pancreas

Solid pseudopapillary tumours (SPT) of the pancreas are uncommon, but with widespread and increased imaging, several of these lesions are coming to light incidentally and are subject to needle biopsies. On limited material and especially the solid or clear cell, variants of SPT can morphologically mimic most notably pancreatic neuroendocrine tumours and even metastatic renal cell carcinoma or melanoma. In this context, immunohistochemistry is important and useful in helping to reach the correct diagnosis. Several antibodies have been used in the immunohistochemical evaluation of SPT. As with most tumours, no one marker is specific, but rather a core panel is advocated. Recently, both beta-catenin and E-cadherin have been shown to be of value in SPT. Nuclear and cytoplasmic decoration of tumour cells by beta-catenin is seen in almost 100% of cases. This protein relocalisation away from the cell membrane is underscored by mutations of the beta-catenin gene. Mutations of the CDH1 gene are very uncommon in SPT, but the immunohistochemically detected changes to the protein are consistent and present in 100% of cases. Using an E-cadherin antibody to the extracellular domain of the molecule results in complete membrane loss, while the antibody directed to the cytoplasmic fragment produces distinct nuclear staining of the tumour cells. In addition, there is concordance of staining abnormalities between the two antibodies. When combined with CD10 and progesterone receptor positivity, a diagnosis of SPT can be rendered with confidence even in small biopsy samples.

Nuclear E-cadherin immunoexpression: from biology to potential applications in diagnostic pathology

E-cadherin is a well-recognized molecule that is important in cell adhesion. Its abrogation has been linked to increased invasiveness in several malignancies. The normal immunohistochemical localization of E-cadherin is the cell membrane, however, both cytoplasmic and nuclear immunostaining has been reported. Loss of membrane staining and/or nuclear staining for E-cadherin is seen in 100% of cases of solid pseudopapillary tumors (SPTs) of the pancreas. In the context of SPT, E-cadherin staining is of diagnostic use. Nuclear staining has been seen in cases of pancreatic neuroendocrine tumors, Merkel cell carcinomas, clear cell renal cell carcinoma, esophageal squamous carcinoma, colorectal and gastric cancer, and synovial sarcoma. The difference in the staining patterns seen (complete loss vs. nuclear staining) is due to the type of E-cadherin antibody used. Antibodies recognizing the extracellular domain show loss of E-cadherin staining in SPT, whereas the antibody to the cytoplasmic domain results in nuclear staining in all cases of SPT. Therefore, E-cadherin staining is of diagnostic use in the immunohistochemical work-up of SPT. Nuclear E-cadherin staining of pancreatic neuroendocrine tumors identified a subset of cases with more aggressive potential, whereas nuclear staining of clear cell renal cancers identified a subset of tumors with a better prognosis. The exact mechanism by which E-cadherin enters the nucleus is not known but it is likely that it is closely related to several partner molecules such as beta-catenin, p120, and presenilin-1.