Expression of desmoglein I in squamous cell carcinoma of the esophagus

Role of Cell-Cell Junctions in Oesophageal Squamous Cell Carcinoma

Cell-cell junctions comprise various structures, including adherens junctions, tight junctions, desmosomes, and gap junctions. They link cells to each other in tissues and regulate tissue homeostasis in critical cellular processes. Recent advances in cell-cell junction research have led to critical discoveries. Cell-cell adhesion components are important for the invasion and metastasis of tumour cells, which are not only related to cell-cell adhesion changes, but they are also involved in critical molecular signal pathways. They are of great significance, especially given that relevant molecular mechanisms are being discovered, there are an increasing number of emerging biomarkers, targeted therapies are becoming a future therapeutic concern, and there is an increased number of therapeutic agents undergoing clinical trials. Oesophageal squamous cell carcinoma (ESCC), the most common histological subtype of oesophageal cancer, is one of the most common cancers to affect epithelial tissue. ESCC progression is accompanied by the abnormal expression or localisation of components at cell-cell junctions. This review will discuss the recent scientific developments related to the molecules at cell-cell junctions and their role in ESCC to offer valuable insights for readers, provide a global view of the relationships between position, construction, and function, and give a reference for future mechanistic studies, diagnoses, and therapeutic developments.

Loss of desmoglein 1 expression associated with worse prognosis in head and neck squamous cell carcinoma patients

AIMS

Mucosal squamous cell carcinomas are the most common head and neck malignancies. We hypothesised that over-expression of intracellular signalling proteins and decreased expression of desmoglein molecules would be associated with aggressive tumour behaviour in patients with head and neck squamous cell carcinoma.

METHODS

Seventy-eight cases of head and neck squamous cell carcinoma were immunohistochemically stained for desmoglein 1, desmoglein 2, desmoglein 3, p53, bcl-2, vimentin, cyclin D1, p16, p21, p27, E-cadherin, and E2F-1 in paraffin-embedded tissue blocks in a microarray.

RESULTS

The disease-specific survival was 56% at 5 years and 49% at 10 years. Expression of the desmoglein isotypes correlated positively with each other except for desmoglein 2 and desmoglein 3, which did not show a significant correlation. Desmoglein 1 and E-cadherin expression also correlated. On univariate analysis, only expression of desmoglein 1 correlated with patient outcome; lack of expression of desmoglein 1 was associated with a significantly worse disease-specific survival (p = 0.035). Hierarchical clustering analysis identified a subgroup of three patients with an immunophenotype distinct from the other tumours, characterised by co-expression of p16, p27, E2F-1 and bcl-2. Further statistical analysis of the prognostic significance of this small subgroup was not possible, but these three patients are alive and well.

CONCLUSIONS

Decreased expression of desmoglein 1 is associated with a worse prognosis in head and neck squamous cell carcinoma patients. Examination of an extended panel of immunomarkers revealed a rare subtype of squamous cell carcinoma characterised by the expression of multiple proliferation-associated markers and the anti-apoptotic protein, bcl-2; determination of the prognostic significance of this subgroup will require study of a larger case series.

Decreased expression of the adhesion molecule desmoglein-2 is associated with diffuse-type gastric carcinoma

Desmoglein-2 (Dsg2) is one of the components of the cell-cell adherence junction. We previously reported that loss of heterozygosity at chromosome 18q12, on which the Dsg2 gene exists, is frequently found in diffuse-type gastric cancers. This study investigated the relationship between Dsg2 expression and diffuse-type gastric cancers. A total of 112 primary tumours resected from patients with gastric cancer were stained with a monoclonal antibody against Dsg2 and examined for correlations between the expression of Dsg2 and various clinicopathological factors, including loss of heterozygosity on chromosome 18q and prognosis. Dsg2 is immunolocalised at cell-cell boundaries in normal gastric mucosa. Loss of Dsg2 expression was observed in 33 of 112 gastric tumours. There was a statistically significant correlation between a decrease in Dsg2 staining and loss of tumour differentiation (P < 0.001), tumour macroscopic feature (P < 0.001) and peritoneal dissemination (P = 0.023), and Dsg2-negative staining was correlated significantly with loss of heterozygosity on chromosome 18q12 (P = 0.001). The prognosis of patients with Dsg2-negative tumours was significantly worse than that of those with Dsg2-positive tumours (log rank, P < 0.01), while multivariate analysis revealed that Dsg2 was not an independent prognostic factor. These findings suggest that decreased expression of Dsg2 is associated with diffuse-type gastric cancers and poor prognosis in gastric carcinoma.

Biologic and imaging diagnosis of lymph node metastasis in esophageal carcinoma

BACKGROUND AND OBJECTIVES

Few reports have described the combined use of biologic and imaging techniques in the diagnosis of lymph node metastasis. We prospectively evaluated lymph node metastasis diagnosed by biologic and imaging means in patients with esophageal carcinoma.

METHODS

Preoperative ultrasound and endoscopic ultrasound (EUS) examination were performed in 80 patients. Biopsy specimens were immunohistochemically examined using cyclin D1 (CD1) and desmoglein 1 (DG1) antibodies, and tumors were classified into three grades.

RESULTS

The sensitivity, specificity, and accuracy values of ultrasound examination were 88.2, 58.6, and 77.5%, respectively. The incidence of nodal involvement was 0% (0/10) in patients with grade 1 tumors, 57.1% (16/28) in those with grade 2 tumors, and 83.3% (35/42) in those with grade 3 tumors. Of the 57 patients with lymph node metastasis determined sonographically, 50 had grade 2 or 3 tumors that were histologically confirmed. The remaining seven patients with grade 1 tumors did not have involved nodes. Of the 23 patients without lymph node metastasis according to ultrasound examination, the incidence of lymph node metastasis in patients with grade 1, 2, and 3 tumors was 0, 16.7, and 50.0%, respectively.

CONCLUSIONS

When used together, imaging and molecular procedures may offer improved identification of lymph node metastasis in patients with squamous cell carcinoma of the esophagus.

Perinuclear and cytoplasmic distribution of desmoglein in esophageal squamous cell carcinomas

The desmosomal glycoproteins desmoglein (Dsg) and desmocollin (Dsc) are members of the cadherin family of cell adhesion molecules. They play an important role in epithelial adhesion. To observe the distribution pattern of Dsg in esophageal squamous cell carcinomas (SCC), immunohistochemical and immunoelectron microscopic analyses were performed. Immunohistochemically, normal esophageal squamous cells strongly expressed Dsg at the cell-cell boundaries, while moderately differentiated esophageal SCC cells showed a perinuclear distribution in addition to the cell boundary staining. At the ultrastructural level, the reaction product was concentrated at the desmosomes in the cell membrane region of normal epithelial cells, but was reduced at the membrane and found throughout the cytoplasm as well as in the surrounding outer nuclear envelope in SCC cells. These results demonstrate an aberrant distribution of Dsg in SCC cells. This may have important consequences for invasion and metastasis, as it may indicate loosened intercellular adhesion.

Biological evaluation of undifferentiated carcinoma of the esophagus

BACKGROUND

Patients with undifferentiated carcinoma of the esophagus (UEC) are rare and have a poor prognosis compared with those with differentiated squamous cell carcinomas (DECs). We compared clinicopathological and biological features of UEC and DEC, with emphasis on markers for epithelial cell origin, proliferation, and cell-cell adhesion.

METHODS

Seven patients with UEC were compared with 21 with DEC. Immunohistochemical studies were performed by using monoclonal antibodies to cytokeratin, epithelial membrane antigen, p53, p21WAF1/CIP1, Ki-67, E-cadherin, desmoglein-1, and thrombomodulin.

RESULTS

Patients with UEC had a poorer prognosis because of hematogenous metastasis at the time of presentation (mean survival, 6.5 +/- 6.2 vs. 35.5 +/- 28.9 months; P < .05). Immunohistochemical findings for cytokeratin and epithelial membrane antigen suggest that some UECs had epithelial origins. The following immunohistochemical profile of UEC was consistent with its highly malignant properties: (1) reduced or negative expression of cell-cell adhesion molecules such as E-cadherin, desmoglein-1, and thrombomodulin, (2) high positive rate for p53 and Ki-67, and (3) negative expression of p21WAF1/CIP1.

CONCLUSIONS

The immunohistochemical findings for UEC showed its high cell-proliferative activity and a high potential for metastasis. Clinical features of UEC were supported by the results of immunohistochemical findings.

The expression of desmoglein isoforms in cultured human keratinocytes is regulated by calcium, serum, and protein kinase C

Three desmoglein (Dsg) isoforms are expressed in a differentiation-specific fashion in the epidermis, with Dsg2 being basal, Dsg3 (pemphigus vulgaris antigen) basal and spinous, and Dsg1 (pemphigus foliaceus antigen) predominantly granular. To better understand the mechanism(s) regulating Dsg isoform expression, we examined the expression pattern of Dsg1, Dsg2, and Dsg3 in normal human epidermal keratinocytes (NHEKs), the immortalized, nontumorigenic HaCaT cell line, and several squamous cell carcinoma cell lines (SCC-9, SCC-12F, SCC-13, and SCC-25). In all cells, the accumulation of high Dsg protein levels required calcium and was not observed in low calcium (0.05-0.07 mM) media. NHEKs expressed Dsg1 in all media tested, consistent with their normal differentiation capacity. HaCaT and SCC-25 also expressed Dsg1; however, the presence of serum in the media dramatically decreased Dsg1 protein levels. Serum also inhibited Dsg1 mRNA levels in HaCaT cells. Dsg1 was not detected in extracts from SCC-9, SCC-12F, and SCC-13 under any conditions. Since activation of protein kinase C (PKC) is involved in keratinocyte differentiation, we evaluated the effects of PKC down-regulation on Dsg isoform expression. Long-term treatment with either the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) or bryostatin 1 inhibited levels of Dsg1 and Dsg3, but not Dsg2 in NHEKs and HaCaT cells. Chronic TPA also decreased Dsg1 and Dsg3 mRNA levels in NHEKs, further supporting a role for PKC activation in the expression of the suprabasal Dsg1 and Dsg3. These results identify several regulatory mechanisms by which the differentiation-specific pattern of desmosomal cadherins is established in the epidermis.

Regulation of desmosomal cell adhesion in human tumour cells by polyunsaturated fatty acids

Desmosomes are key structures in cell-cell adhesion. In this study we examined the effect of n-6 essential fatty acids on the expression of desmoglein (Dsg), desmosomal cadherin and the formation of desmosomes in E-cadherin negative human breast, colon and lung cancer cells and melanoma cells. Electron microscopy revealed that cells cultured with gamma linolenic acid (GLA) showed increased cell-cell adhesion together with an increase in the formation of desmoglein-containing desmosomes. Western blotting studies of cellular proteins demonstrated that, following culture with fatty acids, Dsg expression was modified, with the greatest increase seen after GLA treatment. Other fatty acids increased Dsg expression, but to a lesser extent. It is concluded that GLA regulates desmosome-mediated cell-cell adhesion in human cancer cells, particularly in cells without E-cadherin.

Immunohistochemical detection of p53 and c-erbB-2 in oesophageal carcinoma; no correlation with prognosis

TNM staging of oesophageal cancer provides significant prognostic information but its clinical impact is limited as many patients present with advanced disease (i.e. T3N1). Additional prognostic markers may help separate those with 'good' and 'bad' prognosis tumours and so help with decisions such as selection for adjuvant therapy. p53 and c-erbB-2 overexpression may correlate with poor prognosis in oesophageal cancer, but this is uncertain. This study aimed to investigate the value of these biomarkers as prognostic indicators in resected oesophageal cancer. Two hundred and five oesophageal tumours (127 adenocarcinoma, 78 squamous) resected by a single surgeon between June 1979 and January 1991 were investigated for p53 and c-erbB-2 overexpression using DO-7 and CB-11 immunohistochemistry. Patient survival was analysed by Kaplan-Meir life tables. Median survival was 61 weeks (range: 5-747) and survival diminished significantly with increasing UICC stage (P < 0.0001). Sixty-eight per cent of squamous tumours and 66% of adenocarcinomas overexpressed p53 but there was no statistically significant correlation with prognosis. Twenty-six per cent of squamous tumours and 23% of adenocarcinomas overexpressed c-erbB-2, but again this did not correlate with survival. p53 and c-erbB-2 are commonly overexpressed in oesophageal cancer but do not appear to be related to prognosis in this large series of resected oesophageal cancers and other candidate biomarkers must be sought.