Expression of e-cadherin and catenins in early gastric cancer

Clinical significance of E-Cadherin and β-catenin in early gastric cancer: A protocol of systematic review

BACKGROUND

This study will summarize the clinical significance of E-Cadherin and β-catenin in early gastric cancer (EGC).

METHODS

Eligible case-control studies were searched from Cochrane Library, PUBMED, EMBASE, PsycINFO, Google Scholar, CBM, and CNKI from inception to the present. In addition, we will also search other sources to avoid missing potential studies. Two authors will independently carry out study selection, data collection, and study methodological quality. A fixed or random-effects model will be utilize to synthesize the data, and RevMan 5.3 software will be used for data analysis.

RESULTS

This study will summarize all eligible studies to investigate the clinical significance of E-Cadherin and β-catenin in EGC.

CONCLUSION

The findings of this study may present a genuine understanding of perspective on the clinical significance of E-Cadherin and β-catenin in EGC.

Down-Regulation of miR-2053 Inhibits the Development and Progression of Esophageal Carcinoma by Targeting Fyn-Related Kinase (FRK)

BACKGROUND

MicroRNAs (miRNAs) play essential roles in the regulation and pathophysiology of various types of cancers including esophageal carcinoma (ESCA). Increasing numbers of miRNAs have been identified to be important regulators in the progression of ESCA by regulating gene expression. However, functional miRNAs and the underlying mechanisms involved in ESCA need sufficient elucidation.

AIMS

In the present study, the function of miR-2053 was investigated in ESCA cells.

METHODS

The expression of miR-2053 was detected in four different ESCA cell lines (Eca109, Ec9706, KYSE30, and TE-1 cells) and normal cell line (HEEC) by qRT-PCR. Cell proliferation, migration, and invasion abilities after knockdown of miR-2053 were assessed by CCK-8 assay, scratch assay, and transwell assay, respectively. Cell cycle of ESCA cells was detected by flow cytometric analysis. Expression of proteins in ESCA cells was detected by Western blot analysis.

RESULTS

The results showed that the expression of miR-2053 was remarkably up-regulated in ESCA tissues and cells lines. Down-regulation of miR-2053 markedly inhibited cell proliferation, migration, and invasion and markedly induced cell cycle arrest and cell apoptosis in ESCA cell lines. Fyn-related kinase (FRK) was a target gene of miR-2053. Moreover, down-regulation of miR-2053 mediated the protein kinase B (AKT)/mammalian target of rapamycin and Wnt3a/β-catenin signaling pathway in ESCA cell lines.

CONCLUSIONS

Our results together suggest the potential of regulating miR-2053 expression against development and progression of esophageal carcinoma by targeting FRK.

Effects of Sodium Houttuyfonate on Pulmonary Inflammation in COPD Model Rats

The anti-inflammatory effect of sodium houttuyfonate (SH), an herbal-originated drug that used in China clinically, was investigated on chronic obstructive pulmonary disease (COPD) inflammatory model rats induced by combination usage of cigarette smoke (CS) and lipopolysaccharide (LPS). The morphology of the lung tissue, the expression levels of cytokines in the bronchoalveolar lavage fluid (BALF), the protein levels of TLR4, NF-κB p65, and SIGIRR, and the mRNA levels of TLR4, MyD88, NF-κB p65, and SIGIRR in lung tissues were investigated, respectively. After treated by SH (24.3 mg/kg), the abnormal morphology changes of lung tissues in COPD rats, such as neutrophil infiltration and airway obstruction, were considerably alleviated, as well as both proinflammatory cytokines, TNF-α and IL-1β, significantly decreased in BALF. The mRNA level of TLR4, MyD88, and NF-κB p65 and protein expression of TLR4 and NF-κB p65 in lung tissues decreased significantly after SH treatment, while both SIGIRR mRNA and protein levels increased significantly. These results suggest that SH markedly attenuated the pulmonary inflammation induced by CS and LPS and protected the lung tissue in COPD model rat. The anti-inflammatory effects were related to suppress the TLR4/NF-κB pathway dependent on MyD88. TIR8/SIGIRR might contribute to the protective effects of SH on pulmonary inflammation.

Role of epithelial-mesenchymal transition markers E-cadherin, N-cadherin, β-catenin and ZEB2 in laryngeal squamous cell carcinoma

Epithelial-mesenchymal transition (EMT) allows neoplastic cells to gain the invasive phenotype and become migratory, which is required for cancer progression and metastasis. In the present study, the expression of EMT-associated biomarkers and their association with clinicopathological parameters in laryngeal squamous cell carcinoma (LSCC) was investigated. E-cadherin, N-cadherin, β-catenin and zinc finger E-box binding homeobox 2 (ZEB2) protein expression was evaluated with immunohistochemistry in a cohort of 76 patients with operable LSCC. The association between these transition markers, clinicopathological parameters and their prognostic impact in LSCC was analyzed. Immunohistochemical analysis revealed that EMT-associated proteins were differentially expressed between LSCC and adjacent non-neoplastic laryngeal tissue. Negative E-cadherin expression and positive N-cadherin, β-catenin and ZEB2 expression were associated with a later tumor (T) stage, decreasing tumor differentiation and a reduced overall survival (OS) time (OS: E-cadherin, P=0.016; N-cadherin, P=0.003; β-catenin, P=0.002; ZEB2, P=0.0003). E-cadherin/β-catenin co-expression was significantly associated with the majority of clinicopathological parameters assessed, including lymph node metastases, T stage and tumor cell differentiation (P=0.004, P=0.005, and P<0.001, respectively). Multivariate analysis indicated that T stage and the positive expression of β-catenin and ZEB2 were independent risk factors for OS in LSCC (P=0.014, P=0.025 and P=0.003, respectively). It was concluded that EMT mediates tumor progression, and reduces OS time in patients with LSCC. E-cadherin/β-catenin co-expression may be associated with clinicopathological parameters. T stage, and the positive co-expression of β-catenin and ZEB2 may be independent predictors of prognosis in LSCC.

Low expression of the FoxO4 gene may contribute to the phenomenon of EMT in non-small cell lung cancer

Because of its importance in tumor invasion and metastasis, the epithelial-mesenchymal transition (EMT) has become a research focus in the field of cancer. Recently, evidence has been presented that FoxO4 might be involved in EMT. Our study aimed to detect the expression of FoxO4, E-cadherin and vimentin in non-small cell lung cancers (NSCLCs). We also investigated clinical features and their correlations with the markers. In our study, FoxO4, E-cadherin and vimentin were assessed by immunohistochemistry in a tissue microarray (TMA) containing 150 cases of NSCLC. In addition, the expression level of FoxO4 protein was determined by Western blotting. The percentages of FoxO4, E-cadherin and vimentin positive expression in NSCLCs were 42.7%, 38.7% and 55.3%, respectively. Immunoreactivity of FoxO4 was low in NSCLC when compared with paired normal lung tissues. There were significant correlations between FoxO4 and TNM stage (P<0.001), histological differentiation (P=0.004) and lymph node metastasis (P<0.001), but no significant links with age (P=0.323), gender (P=0.410), tumor size (P=0.084), smoking status (P=0.721) and histological type (P=0.281). Our study showed that low expression of FoxO4 correlated with decreased expression of E-cadherin and elevated expression of vimentin. Cox regression analysis indicated FoxO4 to be an independent prognostic factor in NSCLC (P=0.046). These data suggested that FoxO4 might inhibit the process of EMT in NSCLC, and might therefore be a target for therapy.

Predictable factors for lymph node metastasis in early gastric cancer analysis of clinicopathologic factors and biological markers

Predicting lymph node metastasis (LNM) accurately is very important to decide treatment strategies preoperatively. The aim of this study was to explore risk factors that predict the presence of LNM in early gastric cancer (EGC). A total of 230 patients with EGC who underwent curative gastrectomy with lymph adenectomy at Xinhua Hospital from January 2006 to July 2014 were retrospectively reviewed. We studied the relationship between clinicopathological factors, biological markers (p53, ki67, nm23, vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR), E-cadherin (E-cad), beta-catenin (b-catenin), glutathione S-transferase (GST), and topoisomerase II (Topo II)), and LNM of EGC patients by chi-square test and logistic regression analysis. Meta-analyses were further conducted to review the effects of the proteins (P53, ki67, E-cad, and b-catenin) on LNM in ECG patients. LNM was detected in 42 (18.3 %) of 230 patients. Incidences of LNM was distinct in different tumor size (p = 0.044), depth of submucosal invasion (p < 0.0001), and P53 overexpression (p = 0.004). Multivariate analysis further indentified that large tumor size (≥20 mm, odds ratio (OR) = 2.168, p = 0.041), submucosa (OR = 4.000, p = 0.0005), and P53 overexpression (OR = 3.010, p = 0.022) were independent risk factors of LNM in EGC patients. The meta-analysis revealed a significantly statistical association of P53, ki67, and b-catenin with an increased risk of LNM in EGC patients (P53, OR = 1.81, p = 0.017; ki67, OR = 2.53, p = 0.0003; b-catenin, OR = 0.53, p = 0.01). Tumor size (≥20 mm), the depth of invasion (submucosa), and P53 overexpression may be helpful predictors of LNM in EGC patients. Furthermore, the results of meta-analysis revealed that P53, ki67 overexpression, and abnormal expression of b-catenin may be associated with LNM in EGC. The results need further validation in single large studies.

Levels of soluble E-cadherin in breast, gastric, and colorectal cancers

Soluble E-cadherin is a 80 kDa protein fragment coming from the proteolytic cleavage of the extracellular domain of the full length epithelial cadherin, a molecule involved in cell adhesion/polarity and tissue morphogenesis. In comparison with normal epithelia, cancer cells show a decreased cadherin-mediated intercellular adhesion, and sE-cad levels normally increase in body fluids (blood and urine). This review focuses on soluble E-cadherin in sera of patients affected by three solid cancers (breast, gastric, and colorectal cancers) and how its levels correlate or not with some cancer parameters (e.g., dimension, progression, and localisation). We will describe the main proteomics approaches adopted to measure sE-cad both in vivo and in vitro and the most important findings about its behaviour in cancer dynamics.

Pinocembrin suppresses TGF-β1-induced epithelial-mesenchymal transition and metastasis of human Y-79 retinoblastoma cells through inactivating αvβ3 integrin/FAK/p38α signaling pathway

Background

Pinocembrin is the most abundant flavonoid in propolis. In this study, we investigated the antimetastatic effect of pinocembrin on TGF-β1-induced epithelial-mesenchymal transition (EMT) and metastasis of human Y-79 retinoblastoma cells.

Results

Firstly, the results showed that pinocembrin significantly suppresses the TGF-β1-induced abilities of the invasion and migration of Y-79 cells under non-cytotoxic concentration. Pinocembrin decreased TGF-β1-induced expression of vimentin, N-cadherin, αv and β3 integrin in Y-79 cells. Molecular data also showed pinocembrin inhibits the activation of focal adhesion kinase (FAK) and p38α signal involved in the downregulation of enzyme activities, protein and messenger RNA levels of matrix metalloproteinase-2/9 (MMP-2/-9) induced by TGF-β1. Next, pinocembrin also strongly inhibited the degradation of inhibitor of kappaBα (IκBα) and the nuclear levels of nuclear factor kappa B (NF-κB). Also, a dose-dependent inhibition on the binding ability of NF-κB was further observed under pinocembrin treatment.

Conclusions

Presented results indicated that pinocembrin inhibits TGF-β1-induced epithelial-mesenchymal transition (EMT) and metastasis of Y-79 cells by inactivating the αvβ3 integrin/FAK/p38α signaling pathway. Thus, our findings point to the anticancer potential of pinocembrin against retinoblastoma cells.

β-Catenin serves as a clutch between low and high intercellular E-cadherin bond strengths

A wide range of invasive pathological outcomes originate from the loss of epithelial phenotype and involve either loss of function or downregulation of transmembrane adhesive receptor complexes, including Ecadherin (Ecad) and binding partners β-catenin and α-catenin at adherens junctions. Cellular pathways regulating wild-type β-catenin level, or direct mutations in β-catenin that affect the turnover of the protein have been shown to contribute to cancer development, through induction of uncontrolled proliferation of transformed tumor cells, particularly in colon cancer. Using single-molecule force spectroscopy, we show that depletion of β-catenin or the prominent cancer-related S45 deletion mutation in β-catenin present in human colon cancers both weaken tumor intercellular Ecad/Ecad bond strength and diminishes the capacity of specific extracellular matrix proteins-including collagen I, collagen IV, and laminin V-to modulate intercellular Ecad/Ecad bond strength through α-catenin and the kinase activity of glycogen synthase kinase 3 (GSK-3β). Thus, in addition to regulating tumor cell proliferation, cancer-related mutations in β-catenin can influence tumor progression by weakening the adhesion of tumor cells to one another through reduced individual Ecad/Ecad bond strength and cellular adhesion to specific components of the extracellular matrix and the basement membrane.

Overexpression of cytoplasmic β-catenin inhibits the metastasis of the murine osteosarcoma cell line LM8

Background

Previously, we found that treatment of LM8 murine osteosarcoma cells with genistein, an isoflavone found in soy, increased the cellular level of β-catenin and decreased its invasive and motile potential. The purpose of this study is to investigate whether the expression of β-catenin in LM8 cells is associated with metastatic potential in nude mice. To this end, we used untreated and genistein-treated LM8 cells.

Methods

LM8 cells were treated for 3 days with or without 50 μM genistein and harvested by trypsinization. Untreated (the control group) and genistein-treated (the genistein group) cells were subcutaneously inoculated into the backs of male nude mice. After 25 days of inoculation, the tumors, lungs, and livers were excised, fixed in 10% formalin, and embedded in paraffin. The sections of formalin-fixed, paraffin-embedded lungs and livers were stained with hematoxylin-eosin (H&E) to confirm the absence or presence of metastatic tumors. The expression of β-catenin within the primary tumor was immunohistochemically examined.

Results

All mice in the control group (n = 8) exhibited large primary tumors, while in the genistein group (n = 8), one mouse showed no tumor formation and the remaining seven mice exhibited smaller primary tumors compared with the control group. The tumor mass of the genistein group was 23% of that of the control group. In the control group, multiple metastatic tumors were found in the lung and/or liver and the metastatic incidence was 100% in the lung and 87.5% in the liver. Six of seven tumor-bearing mice in the genistein group developed no metastatic tumors in the lung or liver, and this group was termed the genistein/metastasis(-) subgroup. Positive β-catenin immunostaining was observed in the cytoplasm of tumor cells, and the β-catenin-labeling index was higher in the genistein/metastasis(-) subgroup than in the control group. The intensity of cytoplasmic β-catenin immunostaining was stronger in the genistein/metastasis(-) subgroup compared with the control group, and the β-catenin-labeling score was 1.9-times higher in the former subgroup than in the latter group.

Conclusions

Overexpression of cytoplasmic β-catenin in LM8 cells causes inhibition of the growth of primary tumors and loss of the metastatic potential to the lung and liver.

The cadherin-catenin complex in laryngeal squamous cell carcinoma

Abnormal Wnt signaling and impaired cell–cell adhesion due to abnormal E-cadherin and β-catenin function have been implicated in many cancers, but have not been fully explored in laryngeal squamous cell carcinoma. In this study, β-catenin cellular location and E-cadherin expression levels were analyzed in 16 laryngeal squamous cell carcinomas (LSCCs) (9 glottic and 7 supraglottic) and 11 samples of non-tumoral inflammatory larynx tissue, using immunohistochemical methods. All non-tumoral tissues showed equally strong membranous expression of β-catenin, while cytoplasmic expression was found in only 3 of the 11 samples. By contrast, whereas 8/9 glottic LSCCs exhibited only membranous expression of β-catenin, 6/7 supraglottic LSCCs displayed both membranous and cytoplasmic expression (p = 0.003). Strong E-cadherin staining was observed in 9/11 non-tumoral tissues and 7/9 glottic LSCCs, whereas 4/7 supraglottic LSCCs exhibited weak expression. Reduced membrane expression of E-cadherin and cytoplasmic retention of β-catenin in supraglottic LSCC seems to be related with more aggressive biological behavior which has been described in clinical studies. Further research is required to clarify the involvement of β-catenin in the mechanism associated with malignant transformation in laryngeal tissues.

The cadherin-catenin complex in nasopharyngeal carcinoma

Abnormal Wnt signaling and impaired cell–cell adhesion due to abnormal E-cadherin and β-catenin function have been implicated in many cancers, but have not been fully explored in nasopharyngeal carcinoma. The aim of this study was to analyze β-Catenin cellular location and E-cadherin expression levels in nasopharyngeal carcinoma. E-cadherin expression levels were also correlated with clinical data and underlying pathology. β-Catenin and E-cadherin expression were examined in 18 nasopharyngeal carcinoma and 7 non-tumoral inflammatory pharynx tissues using immunohistochemical methods. Patient clinical data were collected, and histological evaluation was performed by hematoxylin/eosin staining. β-catenin was detected in membrane and cytoplasm in all cases of nasopharyngeal carcinoma, regardless of histological type; in non-tumoral tissues, however, β-catenin was observed only in the membrane. As for E-cadherin expression levels, strong staining was observed in most non-tumoral tissues, but staining was only moderate in nasopharyngeal carcinoma tissues. E-cadherin expression was associated with β-catenin localization, study group, metastatic disease, and patient outcomes. Reduced levels of E-cadherin protein observed in nasopharyngeal carinoma may play an important role in invasion and metastasis. Cytoplasmic β-catenin in nasopharyngeal carcinoma may impair cell–cell adhesion, promoting invasive behavior and a metastatic tumor phenotype.

The expression of E-cadherin-catenin complex in patients with advanced gastric cancer: role in formation of metastasis

The E-cadherin-catenin complex plays an important role in the process of cell adhesion. Its dysfunction is associated with a decrease in cell differentiation and with increased invasiveness and metastasis. Our aim was to evaluate the expression of E-cadherin and B-catenin in advanced gastric cancer in relation to selected clinico-pathomorphological parameters. Formalin-fixed, paraffin-embedded tissue specimens were immunohistochemically stained with monoclonal antibodies E-cadherin (NCL-E-Cad, Novocastra Laboratiries Ltd; dilution 1:50), beta-catenin (NCL-B-CAT, Novocastra Laboratories Ltd; dilution 1:100), alpha-catenin (alpha-E-caten, Santa Cruz Biotechnology; dilution 1:300) and gamma-catenin (gamma-catenin, Santa Cruz Biotechnology; dilution 1:100). The expressions of E-cadherin and alpha-, beta-, gamma-catenins in the main mass of tumor and lymph node metastasis were investigated in 91 patients with gastric cancer. No statistically significant correlation was observed between the expressions of E-cadherin, alpha-, beta-catenins and histological differentiation and between the expressions of E-cadherin, alpha-, gamma-catenins and location or depth of invasion. Moreover, the expression of alpha-, gamma-catenins in the main mass of tumor was not associated with lymph node metastasis. However, we found a relationship between the expression of beta-catenin in the main mass of tumor and lymph node metastasis and tumor location. The depth of invasion was correlated with positive expression of beta-catenin in the main mass of gastric cancer. A statistically significant association was observed between the expressions of E-cadherin and beta-catenin in the main mass of tumor and lymph node involvement. The expression of alpha-catenin in the main mass of tumor was also associated with histological differentiation and Lauren's classification. Statistical analysis showed an association between the expression of E-cadherin and postoperative survival time. No significant correlation was found between the expression of alpha-, beta-, gamma-catenins and survival time. Our results may suggest that the E-cadherin-catenin complex is the factor indicative of metastasis and disease progression in gastric cancer. Also the expression of E-cadherin may play a role as a prognostic factor.

E-cadherin and β-catenin expression in canine colorectal adenocarcinoma

E-cadherin and its associated cytoplasmic proteins, including β-catenin, have been examined as potential oncogenic markers due to the significant correlation between tumour dedifferentiation and the invasive capacity of epithelial tumours. The purpose of this study was to evaluate the expression of E-cadherin and β-catenin in canine colorectal cancer using immunohistochemistry and to examine the relationship between this expression and various clinicopathological variables. The expression pattern of E-cadherin and β-catenin was investigated in 44 colorectal canine carcinomas. In the intestinal mucosa of noncancerous areas, epithelial cells demonstrated equally strong membranous expression of E-cadherin and β-catenin localised to the cell-cell junctions. Reduced expression of E-cadherin and β-catenin was demonstrated in 75% and 81.8% of the colorectal carcinoma cases, respectively. The down-regulation of both E-cadherin and β-catenin was correlated with decreased differentiation and increased tumour grade. In addition, the expression of β-catenin was correlated with tumour size. These results suggest that dysfunction of the E-cadherin-catenin complex starts in the early stages of carcinogenesis and that the disruption of the tissue architecture is progressively associated with the invasion of the tumour.

Molecular aspects in the diagnosis of gastric cancer

BACKGROUND

Gastric cancer (GC) represents the second most common cause of cancer-related death worldwide. The prognosis remains poor, with limited treatment options. A better understanding of the initiation and progression of GC would enable the development of general screening strategies and individualized treatment modalities.

OBJECTIVE

The assessment of tools and molecular markers for the early detection and diagnosis of GC.

METHODS

Human clinical studies published within the past 5 years are reviewed. Also, significant previous data on markers in clinical use or on relevant animal or cell culture experiments are considered.

RESULTS/CONCLUSION

Serum-based screening strategies are not ready for routine application but represent an opportunity for the identification of individuals at high risk with the need for primary gastroscopy and further surveillance, which would ultimately improve survival and prognosis of GC. Infection with Helicobacter pylori represents the principal risk factor for gastric carcinogenesis. Bacterial virulence and host genetic factors contribute to individual susceptibility. Key molecular alterations in gastric carcinogenesis are related to intra- and extracellular cascades that regulate cell proliferation, tumor invasion and metastastic spread. For the development of effective prevention and treatment modalities, it is essential to unravel the basic mechanisms of gastric carcinogenesis.

Cadherin-catenin adhesion system and mucin expression: a comparison between young and older patients with gastric carcinoma

BACKGROUND

Young patients are thought to develop gastric carcinomas with a molecular genetic profile that is distinct from that of gastric carcinomas occurring at a later age. The aim of this study was to compare the clinicopathological features and expression patterns of the markers E-cadherin and beta-catenin, and mucins (MUC1, MUC2, MUC5AC, and MUC6) in young and older patients.

METHODS

The clinicopathological features and overall survival data of 62 young patients (age <or=40 years) with gastric cancer were retrospectively reviewed from hospital records and compared with the data for 453 older patients (age >40 years). A tissue microarray method and immunohistochemistry were used in order to analyze marker expression in paraffin-embedded tissue blocks obtained from both groups.

RESULTS

The young group presented a higher percentage of diffuse-type tumors in comparison to the older group (P<0.01). The rates of positivity for E-cadherin and beta-catenin membranous expression patterns and mucin (MUC2, MUC5AC and MUC6) positivity were higher in the young group (P<0.01). Although young patients showed a lower frequency of alterations in marker expression and had significantly better survival rates than the older patients, neither age nor the marker expression pattern were found to be independent prognostic factors of survival. Only stage, tumor size, and tumor location persisted as prognostic factors for patients with gastric cancer.

CONCLUSION

Biological markers of cellular adhesion and gastric differentiation were differently expressed in young and older patients. Our findings support the hypothesis that young patients develop carcinomas with a different genetic pathway compared to the pathway of tumors occurring at a later age, and we suggest further investigations to assess the prognostic relevance of the markers to specific subgroups.

Lymph node metastasis in submucosal gastric cancer and reduction surgery

Although the concept of early gastric cancer (EGC) has been accepted, lymph node metastasis is the most important prognostic factor for EGC. Submucosal gastric cancer is greatly concerned because of its high lymph node metastasis incidence accounting for about 20% of all lymph node metastases. Many researchers suggest that reduction surgery should be performed for submucosal gastric cancer patients at a lower risk of developing lymph node metastasis. Submucosal gastric cancer can be divided into 3 levels (Sm1, Sm2, Sm3) based on its depth of invasion, which has been proven useful for predicting lymph node metastasis, directing treatment and evaluating prognosis. Recently, with the advances in clinical pathology and molecular biology, the risk factor for lymph node metastasis of submucosal gastric cancer can be accurately evaluated and its treatment has become rather rational. This paper reviews the relative factors for lymph node metastasis of submucosal gastric cancer and advances in its rational surgical treatment.

[Gastric adenocarcinoma: approach to a complex biological reality]

The authors review the complex biological reality of gastric adenocarcinoma from several viewpoints. It is a neoplasm histologically expressed as a dual process (intestinal and diffuse types) with a broad cytological diversity. From an epidemiological point of view, it behaves as an entity with a deep geographical asymmetry and a changing incidence, currently decreasing. There is a multifactorial etiology with a combination of genetic, infectious (H. pylori), nutritional and environmental factors. It might have a multiphasic gestation from precancerous lesions, though not always following a lineal sequence. We only know fragmentary portions of its pathogenesis whose common denominator is a potentially mutagenic mitogenic activation of the epithelial cells implicated. A good knowledge of this complex biological reality will allow the identification of better markers for an early diagnosis as well as vulnerable etiopathogenetic points for a useful prevention and therapy.

Expression and Subcellular Localization of E-Cadherin, .ALPHA.-Catenin, and .BETA.-Catenin in 8 Feline Mammary Tumor Cell Lines

Protein expression and subcellular localization of E-cadherin, alpha-catenin, and beta-catenin in 8 feline mammary tumor cell lines were examined by western blot analysis and fluorescence immunocytochemistry. A low E-cadherin expression was observed in FNN-m cells. Furthermore, compared to other cell lines, two E-cadherin bands existed in FMC-p1 cells and were localized in the perinuclear region; distinct radial lines were observed in the cytoplasm. A low alpha-catenin expression was observed in FON-m cells, but there were no apparent abnormalities in its localization. In contrast, similar levels of beta-catenin expression and cytoplasmic localization were observed in all cell lines.

Differential expression of desmosomal plakophilins in various types of carcinomas: correlation with cell type and differentiation

Plakophilins (PKPs) are a set of 3 constitutive armadillo repeat proteins of the desmosomal plaque, termed PKP 1, PKP 2, and PKP 3, which have been shown to be functionally relevant for desmosomal adhesion. We have performed a systematic immunohistochemical study of the 3 PKPs in oral and pharyngeal squamous cell carcinomas (SqCCs; n = 40); colorectal, pancreatic, and prostate adenocarcinomas (n = 31), and hepatocellular carcinomas (HCCs; n = 8). In SqCCs, PKP 1 and PKP 3 revealed common desmosome-type immunostaining, their expression level being inversely correlated with the degree of malignancy. Instead, staining for PKP 2 was limited. In contrast, all adenocarcinomas contained PKP 2 and-often abundantly-PKP 3 in desmosome-typical pattern, whereas PKP 1 was expressed only in prostate tumors. The presence of PKP 3 in adenocarcinomas was confirmed by immunoblotting. In HCCs, only PKP 2 was detected. Under certain staining conditions, focal nuclear immunoreactivity for PKP 1 was observed in some SqCCs and HCCs. Our results, which are inconsistent with previously published data to some extent, indicate a principal preservation of the cell type and differentiation-related expression patterns of PKPs in normal epithelia. For PKP 1, a suppressor function of malignant behavior seems conceivable, whereas the putative functional significance of its occurrence in tumor cell nuclei requires further studies.

N/A

N/A

Relationship between β-catenin expression and epithelial cell proliferation in gastric mucosa with intestinal metaplasia

AIM: To investigate β-catenin expression in patients with intestinal metaplasia, and to look for a possible relationship between β-catenin expression and either epithelial proliferation values or Helicobacter pylori (H pylori) infection.

METHODS: Twenty patients with complete type intestinal metaplasia were studied. β-catenin expression and epithelial cell proliferation in antral mucosa were assessed using an immunohistochemical analysis. H pylori infection was detected by histology and a rapid urease test.

RESULTS: Reduced β-catenin expression on the surface of metaplastic cells was detected in 13 (65%) out of 20 patients. Moreover, in eight (40%) patients intranuclear expression of β-catenin was found. When patients were analyzed according to H pylori infection, the prevalence of both β-catenin reduction at the cell surface and its intranuclear localization did not significantly differ between infected and uninfected patients. Cell proliferation was higher in patients with intranuclear β-catenin expression as compared to the remaining patients, although the difference failed to reach the statistical significance (36 ± 8.9 vs 27.2 ± 11.4, P = 0.06). On the contrary, a similar cell proliferation value was observed between patients with reduced expression of β-catenin on cell surface and those with a normal expression (28.1 ± 11.8 vs 26.1 ± 8.8, P = 0.7). H pylori infection significantly increased cell proliferation (33.3 ± 10.2% vs 24.6 ± 7.4%, respectively, P = 0.04).

CONCLUSION: Both cell surface reduction and intranuclear accumulation of β-catenin were detected in intestinal metaplasia. The intranuclear localization of β-catenin increases cell proliferation. H pylori infection does not seem to play a direct role in β-catenin alterations, whilst it significantly increases cell proliferation.

Expression of E-cadherin in gastric carcinoma and its correlation with lymph node micrometastasis

AIM: To examine the expression of E-cadherin in the primary tumor and to evaluate its relationship with lymph node micrometastasis (LNM).

METHODS: The authors studied 850 lymph nodes resected from 30 patients with gastric carcinoma who underwent gastrectomy with lymphadenectomy using reverse transcription polymerase chain reaction (RT-PCR) assay in addition to H&E staining. Cytokeratin-20 (CK-20) gene marker was used in this assay. The level of E-cadherin expression in the primary tumor was examined by immunochemical technique (EliVision^TM plus).

RESULTS: LNM was detected in 77 (12.5%) lymph nodes of 14 patients (46.7%) with gastric carcinoma. The incidence of LNM was significantly higher in the diffuse type (12 of 19 cases, 63.2%) than in the intestinal type of gastric carcinoma (2 of 11 cases, 18.2%, P = 0.026). The incidence of LNM also increased in accordance with the depth of tumor invasion. The loss of expression of E-cadherin in primary tumors was found in 14 (46.7) of 30 tumors. The absence of E-cadherin expression was significantly associated with the Lauren classification (P = 0.026), lymph node metastasis (P = 0.011), the grade of differentiation (P = 0.004) and the lymphatic invasion (P = 0.001). Expression of E-cadherin was negative in 10 (71.4%) of the 14 patients with LNM, and in 4 (25%) of the 16 patients without LNM (P = 0.026).

CONCLUSION: The current results indicate that the RT-PCR assay is useful for the detection of LNM and can significantly increase the detection rate of lymph node metastasis in patients with gastric carcinoma. The Lauren classification and depth of tumor invasion are significantly associated with lymph node micrometastases. Our findings also indicate that E-cadherin may play an important role in determining the growth type and differentiation of gastric carcinoma. The loss of E-cadherin expression may contribute to LNM.

CDH1 associated gastric cancer: a report of a family and review of the literature

AIMS

Hereditary diffuse gastric cancer (HDGC) is an autosomal-dominant inherited form of gastric cancer associated with inactivating germline mutations in the CDH1 gene. We set out to outline the role of CDH1 in HDGC. Investigation of a family suspected as having HDGC is discussed. The role of surgery in the management of affected individuals is then examined.

METHODS

A search was conducted of Medline and the National Library of Medicine to identify key articles concerning CDH1 gene mutations, familial gastric cancer and gastrectomy. Further, relevant articles were obtained by manual scanning of the reference lists of identified papers. Mutation-specific CDH1 genetic testing was performed on six living family members and on gastric tissue obtained from two deceased members.

RESULTS

CDH1 mutations cause inactivation of the cell adhesion protein E-cadherin. Carriers of the CDH1 germline gene mutation develop an aggressive, diffuse, submucosal gastric cancer at an early age. Current endoscopic screening is ineffective at detecting HDGC. The presence of a CDH1 germline gene mutation was confirmed in both deceased family members and also in four of the six living members tested.

CONCLUSION

Genetic counselling and CDH1 gene mutation testing is indicated in families with suspected HDGC. In the absence of a satisfactory surveillance mechanism, prophylactic total gastrectomy would appear to be an appropriate therapeutic option in mutation carriers.

Overexpression of LI-cadherin in gastric cancer is associated with lymph node metastasis

Gastric cancer remains the second leading cause of cancer deaths worldwide. Patients usually present late with local invasion or metastatic diseases. The present study investigated the expression level of liver-intestine cadherin (LI-cadherin) by RT-PCR and its correlation with clinicopathological data in 71 pairs of tumor and non-cancerous gastric mucosa. Protein expression level of LI-cadherin was determined by Western blotting and immunohistochemistry. The mRNA of LI-cadherin was highly expressed in tumor as compared to non-cancerous mucosa. Lymph node metastasis was significantly associated with the expression of LI-cadherin (p=0.038). On multivariate analysis, T staging and LI-cadherin expression were found to be independent factors associated with lymph node metastasis.

Abnormal expression of E-cadherin in early gastric carcinoma: its relationship with macroscopic growth patterns and catenin alpha and beta

BACKGROUND

Abnormal expression of E-cadherin plays an important role in the differentiation and progression of gastric carcinoma. There are a few identifiable clinical, histopathologic, and molecular changes that are related with the macroscopic growth patterns of gastric carcinoma. The aim of this study is to elucidate the relation between the macroscopic growth patterns of gastric carcinoma and the abnormal expression of E-cadherin, alpha- and beta-catenins.

STUDY

A total of 97 cases of early gastric carcinoma were examined by immunohistochemistry using monoclonal antibodies against E-cadherin, alpha- and beta-catenins. Macroscopically, 52 cases were elevated types and 45 cases were depressed types.

RESULTS

Early gastric carcinomas with depressed growth showed diffuse histologic type, younger patients' age and smaller size more frequently than tumors with elevated growth. Abnormal expression rates of E-cadherin, alpha- and beta-catenins were 35.1, 36.1, and 46.4%, respectively. Abnormal expression of E-cadherin, alpha- and beta-catenins was significantly associated with depressed tumor growth and diffuse histologic type. By multiple logistic regression analysis. E-cadherin, age, Lauren classification, World Health Organization grade and size were identified as risk factors of macroscopic growth pattern of early gastric carcinomas. Positive associations between E-cadherin and beta-catenin and between alpha- and beta-catenins were found by log linear model analysis.

CONCLUSION

We suggest that E-cadherin plays an important role in the macroscopic growth as well as microscopic differentiation of early gastric carcinomas.

Variable E-cadherin expression in a MNU-induced colon tumor model in rats which exposed with 50 Hz frequency sinusoidal magnetic field

Inactivation of the E-cadherin system by multiple mechanisms, including both genetic and epigenetic events, plays a significant role in multistage carcinogenesis. We have investigated the effects of sinusoidal electromagnetic fields (SMF) on E-cadherin expression in an MNU (N-methyl-N-nitrosurea)-induced colon tumor model. Male wistar albino rats were used for the study. The rats were classified into four groups: I (MNU), II (SMF+MNU), III (SMF) and IV (control). After administered at MNU in 1st and 2nd groups, 2nd and 3rd groups were exposed to a sinusoidal magnetic field (SMF, 50 Hz, 5 mT) for 6 hours/day for 8 months. The expression of E-cadherin were examined in four groups of rat colon tissues by immunohistochemistry on paraffin sections. For immunohistochemical analysis, the labeled streptavidin biotin method was performed using a Vectastain Universal Quick Kit with microwave accentuation. Fisher's exact test was used for statistical analysis between proportions. Immunohistochemical studies of E-cadherin expression in this model demonstrated significant differences for cytoplasmic expression pattern. These results suggest that the electromagnetic fields result in significant alterations in cell adhesion mechanisms. This study has implications for understanding the role of fields in cell detachment in cancer metastasis. Further work is required to determine the relative effect of the magnetic fields on these phenomena.