Clinicopathological significance of Necl-4 expression in pancreatic ductal adenocarcinoma

AIMS

The loss, or decreased expression, of nectin-like molecule 4 (Necl-4; an immunoglobulin-like cell adhesion molecule) is reported to be associated with the development and progression of certain types of cancer. We investigated the clinicopathological significance of Necl-4 expression in patients with pancreatic ductal adenocarcinoma (PDAC).

METHODS

Immunohistochemical analyses of Necl-4 (n=258) and E-cadherin (n=256) expression were performed using tissue microarray blocks of PDAC samples. Necl-4 expression of 38 pancreatic intraepithelial neoplasia (PanIN) lesions included in tissue microarray cores was also evaluated. Necl-4 and E-cadherin expression was considered positive if >30% of cells were stained, and negative if ≤30% of cells were stained.

RESULTS

Necl-4 expression was positive in 45.7% (n=118) and negative in 54.3% (n=140) of PDAC cases. Necl-4 staining was positive in 96.7% (n=29) and negative in 3.3% (n=1) of low-grade PanIN cases, and positive in 62.5% (n=5) and negative in 37.5% (n=3) of high-grade PanIN cases. The number of cases with positive Necl-4 expression decreased in the order low-grade PanIN>high-grade PanIN>PDAC (p<0.001). Negative Necl-4 expression was significantly associated with a larger tumour size of >30 mm, perineural invasion, lymphatic involvement, lymph node metastasis (pN1), an advanced TNM (tumour, node, metastases) stage (stage IIB-IV), an advanced histological grade (G2/3), and shorter overall survival. E-cadherin staining was positive in 46.1% (n=118) and negative in 53.9% (n=138) of PDAC cases. Necl-4 expression correlated positively with E-cadherin expression (r=0.405, p<0.001).

CONCLUSIONS

The results suggest that Necl-4 is associated with carcinogenesis and aggressiveness of PDAC.

Reacquisition of E-cadherin expression in metastatic deposits of signet-ring cell carcinoma of the upper gastrointestinal system: a potential anchor for metastatic deposition

AIMS

To examine the expression of E-cadherin in paired primary and metastatic signet-ring cell carcinomas (SRCC) of various organ systems in order to explore the potential role of the molecule in metastatic dissemination of this unique tumour type.

METHODS

Thirty-seven consecutive cases of SRCC from various organs with paired primary and metastatic tumorous tissue available were retrieved. The intensity of membranous E-cadherin expression was semiquantitatively scored on a scale of 0-3+.

RESULTS

Reduced E-cadherin expression was a distinct feature of primary SRCC and was observed in 78% of primary tumours. Interestingly, the E-cadherin reduction was less frequently seen in metastatic SRCC when compared with their primary counterparts, and was only found in 57% of tumours in lymph node metastases or at distant sites of relapse. Furthermore, the mean score of E-cadherin expression of primary SRCC was significantly lower than that of their metastatic counterparts (2.3 vs 1.8; p=0.008). When divided by organ systems, the reacquisition of E-cadherin expression in the metastatic deposits was most remarkable in the SRCC of upper gastrointestinal tract origin (2.3 vs 1.4; p=0.003), whereas no significant difference was observed in other organ systems.

CONCLUSIONS

While the reduction of E-cadherin in primary SRCC supports its pivotal role in epithelial-mesenchymal transition, a process crucial in tumour progression and metastatic dissemination, the re-expression of this molecule in metastatic SRCC cells implies a reversal to their epithelial phenotype (thus mesenchymal-epithelial transition) which, in turn, theoretically helps tumour cells to anchor and form cohesive metastatic deposits.

Carcinoembryonic Antigen Cell Adhesion Molecule 1 long isoform modulates malignancy of poorly differentiated colon cancer cells

OBJECTIVE

Nearly 20%-29% of patients with colorectal cancer (CRC) succumb to liver or lung metastasis and there is a dire need for novel targets to improve the survival of patients with metastasis. The long isoform of the Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1-L or CC1-L) is a key regulator of immune surveillance in primary CRC, but its role in metastasis remains largely unexplored. We have examined how CC1-L expression impacts on colon cancer liver metastasis.

DESIGN

Murine MC38 transfected with CC1-L were evaluated in vitro for proliferation, migration and invasion, and for in vivo experimental liver metastasis. Using shRNA silencing or pharmacological inhibition, we delineated the role in liver metastasis of Chemokine (C-C motif) Ligand 2 (CCL2) and Signal Transducer and Activator of Transcription 3 (STAT3) downstream of CC1-L. We further assessed the clinical relevance of these findings in a cohort of patients with CRC.

RESULTS

MC38-CC1-L-expressing cells exhibited significantly reduced in vivo liver metastasis and displayed decreased CCL2 chemokine secretion and reduced STAT3 activity. Down-modulation of CCL2 expression and pharmacological inhibition of STAT3 activity in MC38 cells led to reduced cell invasion capacity and decreased liver metastasis. The clinical relevance of our findings is illustrated by the fact that high CC1 expression in patients with CRC combined with some inflammation-regulated and STAT3-regulated genes correlate with improved 10-year survival.

CONCLUSIONS

CC1-L regulates inflammation and STAT3 signalling and contributes to the maintenance of a less-invasive CRC metastatic phenotype of poorly differentiated carcinomas.

Intestinal deletion of Claudin-7 enhances paracellular organic solute flux and initiates colonic inflammation in mice

OBJECTIVE

To design novel anti-inflammation treatments, it is important to recognise two distinct steps of inflammation: initiation and acceleration. In IBDs, intestinal inflammation is reported to be accelerated by dysfunction in the epithelial paracellular barrier formed by tight junctions (TJs). However, it is unclear whether changes in paracellular barrier function initiate inflammation. Some of the intestinal claudin-family proteins, which form the paracellular barrier, show aberrant expression levels and localisations in IBDs. We aimed to elucidate the role of paracellular-barrier change in initiating colonic inflammation.

DESIGN

We generated intestine-specific conditional knockout mice of claudin-7 (Cldn7), one of the predominant intestinal claudins.

RESULTS

The intestine-specific Cldn7 deficiency caused colonic inflammation, even though TJ structures were still present due to other claudins. The paracellular flux (pFlux), determined by measuring the paracellular permeability across the colon epithelium, was enhanced by the Cldn7 deficiency for the small organic solute Lucifer Yellow (457 Da), but not for the larger organic solute FITC-Dextran (4400 Da). Consistent with these results, the intestine-specific claudin-7 deficiency enhanced the pFlux for N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP) (438 Da), a major bacterial product, to initiate colonic inflammation.

CONCLUSIONS

These findings suggest that specific enhancement of the pFlux for small organic solutes across the claudin-based TJs initiates colonic inflammation.

Fascin-1 expression as stratification marker in borderline epithelial tumours of the ovary

AIMS

To evaluate the actin-bundling protein fascin-1 (FSCN1) as marker for borderline ovarian tumours (BOTs).

METHODS

We analysed a retrospective cohort of 140 BOTs with validated diagnosis by an independent pathologist. Immunohistochemical detection of FSCN1 was quantified as combined immunoreactive score (CIS) blinded to clinical patient data. Analyses were first performed for FSCN1 positive versus negative, and then verified using three categories derived from the observed distribution (negative, weak, strong; CIS 0, 1-2, 3-9).

RESULTS

We detected FSCN1 positivity in 51.4%, and strong expression (CIS 3-9) in 14.3% of the samples. FSCN1 positivity was associated with serous subtype (p<0.001) and micropapillary pattern (p<0.001). Correlation with micropapillary pattern remained significant within the serous BOT (SBOT) subgroup (p=0.022). Strong FSCN1 expression (CIS 3-9) was associated both with the presence of implants (p=0.022), and a higher International Federation of Gynecology and Obstetrics (FIGO) stage (p=0.020).

CONCLUSIONS

Our analysis links FSCN1 with SBOT with micropapillary pattern. Strong expression is associated with higher FIGO stage and the presence of implants, both related to elevated risk of recurrence. Hence, FSCN1 is an interesting marker worth further analyses of its prognostic value in BOTs.

Ultrastructural features of eosinophilic oesophagitis: impact of treatment on desmosomes

AIMS

A growing body of evidence suggests a role for altered epithelial barrier function in the pathophysiology of eosinophilic oesophagitis (EoE), but few have described the epithelial structure during inflammation. The purpose of this study was to define ultrastructural features of active, inactive EoE and control subject's oesophageal epithelia.

METHODS

We prospectively enrolled patients undergoing diagnostic upper endoscopy for evaluation of EoE. Mucosal pinch biopsies were obtained from the distal oesophagus and processed for routine histology and electron microscopic assessment. Clinical features of enrolled subjects were analysed and subjects were divided into four groups: normal, gastroesophageal reflux disease (GERD), inactive EoE and active EoE. Representative photomicrographs of the basal and superficial epithelia were reviewed for abnormalities. Desmosomes were quantified on the surface of epithelia three to four prickle-cell layers above the basal layer.

RESULTS

Twenty-nine paediatric cases (ages 2-18 years) were enrolled in the study. We observed a significant decrease in the number of desmosomes per cell (DPC) of subjects with active EoE compared with inactive EoE, GERD and normal epithelia. With respect to DPC, no significant differences were found between inactive EoE compared with GERD or normal subjects. Additional ultrastructural features observed included epithelial microplicae and evidence of eosinophil transmigration, degranulation, and sombrero formation.

CONCLUSIONS

Consistent with clinical and molecular findings, our ultrastructural data provide support for an altered oesophageal barrier in paediatric cases with active EoE, which may improve following treatment.

Update on basic and clinical aspects of eosinophilic oesophagitis

The identification of a distinct syndrome, designated eosinophilic oesophagitis (EoE), with its own clinical and histopathological characteristics, was first described in the early 1990s. Meanwhile intense research has uncovered many molecular, immunological and clinical aspects of this chronic-inflammatory disorder. This article focuses exclusively on basic and clinical insights of EoE gathered during the last few years. Regarding aetiopathogenesis it has become clear that EoE is a food-triggered disease with milk and wheat as the dominant culprit food categories. However, it is still debated whether a disturbed mucosal integrity allowing allergens to cross the mucosal barrier, or changes in wheat and milk manufacturing might induce these inflammatory responses. Furthermore, basic science and clinical studies have accordingly confirmed that a chronic eosinophilic inflammation leads to a remodelling of the oesophagus with micro- and macro-morphological alterations, ending in a strictured oesophagus with impaired function. Fortunately, long-term therapeutic trials, using either topical corticosteroids or dietary allergen avoidance, have demonstrated that this sequela can be prevented or even reversed. This finding is of clinical relevance as it supports the initiation of a consistent anti-inflammatory therapy. Nevertheless, EoE is still an enigmatic disease and the long list of unanswered questions will certainly stimulate further research.

Expression of EpCAM(MF) and EpCAM(MT) variants in human carcinomas

Aims

Regulated intramembrane proteolysis has been shown to be an important mechanism for oncogenic activation of epithelial cell adhesion molecule (EpCAM) through nuclear translocation of the intracellular domain EpICD. Recent studies have identified new membrane-bound EpCAM variants. To evaluate the prevalence of two membranous EpCAM variants in human tumours, we performed a large-scale expression analysis using specific antibodies against the extracellular domain EpEX (MOC-31 clone) and the intracellular domain EpICD (9-2 clone) of the EpCAM antigen by immunohistochemistry.

Material and methods

Two multi-tissue microarrays (TMA) series containing 1564 tissue samples each of 53 different histological tumour types were stained and compared. One TMA was stained for EpEX and one for EpICD. Membranous full-length EpCAM (EpCAM^MF) expression in tissues was defined by the expression of EpEX and EpICD, while the truncated variant of EpCAM (EpCAM^MT) was characterised by a significant loss of membranous EpICD expression compared with EpEX expression.

Results

We defined tumours with high EpCAM^MT expression (ie, cancers of the endometrium and bladder), tumours with intermediate (ie, gastric, pancreatic, colorectal and oesophageal cancer) and tumours with low rates of expression of the EpCAM^MT variant (ie, lung, ovarian, gallbladder, breast and prostate cancer).

Conclusions

Our results indicate that loss of membranous EpICD expression is a common event in human epithelial carcinomas, arguing for the expression of different degrees of EpCAM^MF and EpCAM^MT variants across the most important tumour entities. Future studies evaluating the prognostic and predictive role of these variants in human malignancies, especially in patients treated with EpCAM-specific antibodies, are clearly warranted.