Soluble E-cadherin is an independent pretherapeutic factor for long-term survival in gastric cancer

Salivary and serum levels of soluble E-cadherin in patients with gastrointestinal cancers: A comparative study

AIM

According to the literature, high levels of salivary soluble E-cadherin may be lined to advanced stage and poor prognosis in cancers. This research aimed at comparing salivary and serum levels of soluble E-cadherin in cases with esophageal, gastric, and colorectal cancers.

METHODS

This case-control research was performed on 68 patients with gastrointestinal cancers and 57 healthy volunteers as a control group to measure salivary and serum levels of soluble E-cadherin using ELISA kits.

RESULTS

The results showed a statistically significant difference between salivary and serum levels of soluble E-cadherin in the case group, as opposed to the control group (P = 0.031). The salivary level of soluble E-cadherin in the control group was 2.138 ng/mL on average lower than that that in the case group. The median salivary level of soluble E-cadherin among cases with lymph node involvement was significantly higher compared with its median level in the control group (P = 0.049). Soluble E-cadherin salivary level and other variables, such as metastasis and cancer stage, were directly correlated, but it was not statistically significant.

CONCLUSION

According to the findings, the salivary level of soluble E-cadherin among cases with gastric cancer could be considered as a prognostic marker, but the diagnostic value of saliva could not be judged in esophageal and colorectal cancers because of small sample size, and more investigations are required for a definite conclusion.

MMP9: A Tough Target for Targeted Therapy for Cancer

Having the capability to proteolyze diverse structural and signaling proteins, matrix metalloproteinase 9 (MMP9), one of the best-studied secretory endopeptidases, has been identified as a crucial mediator of processes closely associated with tumorigenesis, such as the extracellular matrix reorganization, epithelial to mesenchymal transition, cell migration, new blood vessel formation, and immune response. In this review, we present the current state of knowledge on MMP9 and its role in cancer growth in the context of cell adhesion/migration, cancer-related inflammation, and tumor microenvironment formation. We also summarize recent achievements in the development of selective MMP9 inhibitors and the limitations of using them as anticancer drugs.

Overview on the Role of E-Cadherin in Gastric Cancer: Dysregulation and Clinical Implications

Gastric cancer is the fifth most common cancer and the third most common cause of cancer death all over the world. E-cadherin encoded by human CDH1 gene plays important roles in tumorigenesis as well as in tumor progression, invasion and metastasis. Full-length E-cadhrin tethered on the cell membrane mainly mediates adherens junctions between cells and is involved in maintaining the normal structure of epithelial tissues. After proteolysis, the extracellular fragment of the full-length E-cadhein is released into the extracellular environment and the blood, which is called soluble E-cadherin (sE-cadherin). sE-cadherin promots invasion and metastasis as a paracrine/autocrine signaling molecule in the progression of various types of cancer including gastric cancer. This review mainly summarizes the dysregulation of E-cadherin and the regulatory roles in the progression, invasion, metastasis, and drug-resistance, as well as its clinical applications in diagnosis, prognosis, and therapeutics of gastric cancer.

CD82 Suppresses ADAM17-Dependent E-Cadherin Cleavage and Cell Migration in Prostate Cancer

CD82 acts as a tumor suppressor in a series of steps in malignant progression. Here, we identified a novel function of CD82 on posttranslational regulating E-cadherin in prostate cancer. In our study, the declined expression of CD82 was verified in prostate cancer tissues and cell lines compared with normal tissue and cell lines. Functionally, CD82 inhibited cell migration and E-cadherin cleavage from the cell membrane in prostate cancer cell. Further study proved that a disintegrin and metalloproteinase ADAM17 as an executor of E-cadherin cleavage mediated the inhibitory regulation of CD82 in E-cadherin shedding in prostate cancer. Specifically, CD82 interacted with ADAM17 and inhibited its metalloprotease activity, which led to the descent of E-cadherin shedding. These results show a nuanced but important role of CD82 in nontranscriptional regulation of E-cadherin, which may help to understand the intricate regulation of dysfunctional adhesion molecule in cancer progression.

E-cadherin and Snail Immunoexpression in Colorectal Adenocarcinomas

Epithelial-mesenchymal transition (EMT) is a fundamental process which governs invasiveness. E-cadherin plays a major role in development, organogenesis and tissue formation, but also in tumor progression. Snail is a transcription factor described as a direct repressor of E-cadherin during development and in carcinogenesis. In this study we analyzed E-cadherin and Snail immunoexpression in 47 cases of colorectal adenocarcinoma (CRC) in comparison with some histopathological prognostic factors. The majority of cases were G2 tumors in stages II and III, with vascular and perineural invasion. All cases showed positive cytoplasmic signal for E-cadherin and Snail. E-cadherin reactions were intense with the highest composite score (CS) values in CRC G1. CS values of E-cadherin decreased with the advancement in tumor stage and the association with vascular and perineural invasion was statistically significant. Snail immunoreaction was intense with the highest values of CS in CRC G3, being more evident with the increase of tumor staging, aspect which was statistically significant. CS and Snail association demonstrated a statistically significant aspect related to vascular invasion. We found a negative linear correlation of E-cadherin and Snail expression. The obtained results indicate the implication of Snail and E-cadherin in EMT of CRC, aspect which is useful in the evaluation and stratification of patients with CRC for the targeted specific therapy.

Involvement of microRNAs-MMPs-E-cadherin in the migration and invasion of gastric cancer cells infected with Helicobacter pylori

It has been found that Helicobacter pylori （H. pylori）is not only the main cause of gastric cancer, but also closely related to its metastasis. E-cadherin cleavage induced by matrix metalloproteinases (MMPs) plays an important role in the tumor metastasis. In the present study, we investigated the role of microRNAs-MMPs-E-cadherin in migration and invasion of gastric cancer cells treated with H. pylori. The results showed that H. pylori induced migration and invasion of SGC-7901 cells with a down-regulation of E-cadherin expression, which were abolished by MMPs knock down, E-cadherin overexpression, mimics of miR128 and miR148a. MiR128/miR148a inhibitors restored MMP-3/MMP-7 expression, down-regulated E-cadherin level, and accelerated cellular migration and invasion. This study suggests that H. pylori induces migration and invasion of gastric cancer cells through reduction of E-cadherin function by activation of MMP-3, - 7. The present results also suggest that the activated MMPs/E-cadherin pathway is related with down-regulation of miR128/miR148a in the human gastric cancer cells infected with H. pylori.

Correlation of E-cadherin gene polymorphisms and epidermal growth factor receptor mutation in lung adenocarcinoma

Epithelial-mesenchymal transition (EMT) was recently discovered related to the efficacy of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) in NSCLC patients and cell lines. In this study, we aimed to explore the association among the E-cadherin gene (CDH1) genetic variants, TK-domain mutations of EGFR, and clinicopathologic characteristics in patients with lung adenocarcinoma. A total of 280 patients with lung adenocarcinoma were recruited between years 2012 and 2015. All subjects underwent the analysis of CDH1 genetic variants (rs16260 and rs9929218) by real-time polymerase chain reaction (PCR) genotyping. The results showed that CA and CA + AA genotypes of CDH1 single nucleotide polymorphism (SNP) rs16260 were significantly reverse associated with EGFR mutation type (Adjusted odds ratio (AOR) = 0.43, 95% CI = 0.20-0.92 and AOR = 0.46, 95% CI = 0.22-0.96, respectively) in female lung adenocarcinoma patients. Moreover, the significantly reverse associations between CA and CA + AA genotypes of CDH1 rs16260 and EGFR hotspot mutations, namely L858R mutation and exon 19 in-frame deletion, were also demonstrated among female patients. Besides, CA + AA genotype of CDH1 rs16260 was noted significantly reverse associated with the tumor sizes (OR = 0.31, 95% CI = 0.12-0.80; p = 0.012). In conclusion, our results suggested that CDH1 variants are significantly reverse associated with mutation of EGFR tyrosine kinase, especially among the female patients with lung adenocarcinoma. The CDH1 variants might contribute to pathological development in lung adenocarcinoma.

miR-206/133b Cluster: A Weapon against Lung Cancer?

Lung cancer is a deadly disease that ends numerous lives around the world. MicroRNAs (miRNAs) are a group of non-coding RNAs involved in a variety of biological processes, such as cell growth, organ development, and tumorigenesis. The miR-206/133b cluster is located on the human chromosome 6p12.2, which is essential for growth and rebuilding of skeletal muscle. The miR-206/133b cluster has been verified to be dysregulated and plays a crucial role in lung cancer. miR-206 and miR-133b participate in lung tumor cell apoptosis, proliferation, migration, invasion, angiogenesis, drug resistance, and cancer treatment. The mechanisms are sophisticated, involving various target genes and molecular pathways, such as MET, EGFR, and the STAT3/HIF-1α/VEGF signal pathway. Hence, in this review, we summarize the role and potential mechanisms of the miR-206/133b cluster in lung cancer.

Proteolysis in Helicobacter pylori-Induced Gastric Cancer

Persistent infections with the human pathogen and class-I carcinogen Helicobacter pylori (H. pylori) are closely associated with the development of acute and chronic gastritis, ulceration, gastric adenocarcinoma and lymphoma of the mucosa-associated lymphoid tissue (MALT) system. Disruption and depolarization of the epithelium is a hallmark of H. pylori-associated disorders and requires extensive modulation of epithelial cell surface structures. Hence, the complex network of controlled proteolysis which facilitates tissue homeostasis in healthy individuals is deregulated and crucially contributes to the induction and progression of gastric cancer through processing of extracellular matrix (ECM) proteins, cell surface receptors, membrane-bound cytokines, and lateral adhesion molecules. Here, we summarize the recent reports on mechanisms how H. pylori utilizes a variety of extracellular proteases, involving the proteases Hp0169 and high temperature requirement A (HtrA) of bacterial origin, and host matrix-metalloproteinases (MMPs), a disintegrin and metalloproteinases (ADAMs) and tissue inhibitors of metalloproteinases (TIMPs). H. pylori-regulated proteases represent predictive biomarkers and attractive targets for therapeutic interventions in gastric cancer.

Expression profile of E-cadherin, estrogen receptors, and P53 in early-onset gastric cancers

Early-onset gastric cancer (EOGC) is predominant in females, diffuse histology, and hereditary pattern. Germline mutation of CDH1 and p53 has been reported previously and female dominance was speculated to be associated with estrogen and its receptors. Expression of E-cadherin, estrogen receptor α (ERα), estrogen receptor β (ERβ), and p53 in EOGC remains unclear, which was the focus of this study, to assess clinical significance of their expression in EOGC. The expression of E-cadherin, ERα, ERβ, and p53 in tumors and normal tissues from surgically resected EOGCs was assessed by immunohistochemistry (n = 139) and Western blot (n = 7) methods, respectively. The expression in tumor tissues was significantly higher for ERα, ERβ, and p53, but lower for E-cadherin, compared to uninvolved mucosa. Positive staining of ERβ and p53 was more frequently observed in younger patients with advanced TNM stages. For E-cadherin, significant correlation was observed between the immunopositivity and TNM stages IA+IB. P53-negative patients had significantly better outcomes than p53-positive patients. Significant association between expression of E-cadherin and histologic types was found in familial, but not in sporadic, EOGC. In conclusion, our results demonstrated E-cadherin may have a role in initiation of EOGC and positive ERβ and p53 expression may partially explained early-onset and tumor progression of EOGC.

Expression of Epithelial-Mesenchymal Transition-related Factors in Adherent Placenta

Epithelial-mesenchymal transition is a key process influencing cancer progression and metastasis. The purpose of this study was to investigate the expression of epithelial-mesenchymal transition-related factors in chorionic villi and decidual cells in adherent placenta. The current study included 19 patients diagnosed with adherent placenta after hysterectomy. The expression of E-cadherin, Vimentin, Snail, and transforming growth factor-β in placental tissues was analyzed by immunohistochemical staining. Immunostaining intensity was semiquantitatively evaluated using the HSCORE algorithm. In the chorionic villi of the invasive part (placenta with invasion into myometrium), E-cadherin expression was significantly lower than that in the noninvasive part (placenta with no invasion). In the decidual cells of the invasive part, expression of transforming growth factor-β and Snail significantly increased. These results suggest that epithelial-mesenchymal transition may contribute to excessive trophoblast invasion into the myometrium in adherent placenta.

Beyond a tumor suppressor: Soluble E-cadherin promotes the progression of cancer

E-cadherin (E-cad) plays important roles in tumorigenesis as well as in tumor progression, invasion and metastasis. This protein exists in two forms: a membrane-tethered form and a soluble form. Full-length E-cad is membrane tethered. As a type I transmembrane glycoprotein, E-cad mainly mediates adherens junctions between cells and is involved in maintaining the normal structure of epithelial tissues. Soluble E-cad (sE-cad) is the extracellular fragment of the protein that is cleaved from the membrane after proteolysis of full-length E-cad. The production of sE-cad undermines adherens junctions, causing a reduction in cell aggregation capacity; furthermore, sE-cad can diffuse into the extracellular environment and the blood. As a paracrine/autocrine signaling molecule, sE-cad activates or inhibits multiple signaling pathways and participates in the progression of various types of cancer, such as breast cancer, ovarian cancer, and lung cancer, by promoting invasion and metastasis. This article briefly reviews the role of sE-cad in tumorigenesis and tumor progression and its significance in clinical therapeutics.

Identification of Serum Biomarkers for Gastric Cancer Diagnosis Using a Human Proteome Microarray

We aimed to globally discover serum biomarkers for diagnosis of gastric cancer (GC). GC serum autoantibodies were discovered and validated using serum samples from independent patient cohorts encompassing 1,401 participants divided into three groups, i.e. healthy, GC patients, and GC-related disease group. To discover biomarkers for GC, the human proteome microarray was first applied to screen specific autoantibodies in a total of 87 serum samples from GC patients and healthy controls. Potential biomarkers were identified via a statistical analysis protocol. Targeted protein microarrays with only the potential biomarkers were constructed and used to validate the candidate biomarkers using 914 samples. To provide further validation, the abundance of autoantibodies specific to the biomarker candidates was analyzed using enzyme-linked immunosorbent assays. Receiver operating characteristic curves were generated to evaluate the diagnostic accuracy of the serum biomarkers. Finally, the efficacy of prognosis efficacy of the final four biomarkers was evaluated by analyzing the clinical records. The final panel of biomarkers consisting of COPS2, CTSF, NT5E, and TERF1 provides high diagnostic power, with 95% sensitivity and 92% specificity to differentiate GC patients from healthy individuals. Prognosis analysis showed that the panel could also serve as independent predictors of the overall GC patient survival. The panel of four serum biomarkers (COPS2, CTSF, NT5E, and TERF1) could serve as a noninvasive diagnostic index for GC, and the combination of them could potentially be used as a predictor of the overall GC survival rate.

Carcinoma cells induce lumen filling and EMT in epithelial cells through soluble E-cadherin-mediated activation of EGFR

In epithelial cancers, carcinoma cells coexist with normal cells. Although it is known that the tumor microenvironment (TME) plays a pivotal role in cancer progression, it is not completely understood how the tumor influences adjacent normal epithelial cells. In this study, a three-dimensional co-culture system comprising non-transformed epithelial cells (MDCK) and transformed carcinoma cells (MSV-MDCK) was used to demonstrate that carcinoma cells sequentially induce preneoplastic lumen filling and epithelial-mesenchymal transition (EMT) in epithelial cysts. MMP-9 secreted by carcinoma cells cleaves cellular E-cadherin (encoded by CDH1) from epithelial cells to generate soluble E-cadherin (sE-cad), a pro-oncogenic protein. We show that sE-cad induces EGFR activation, resulting in lumen filling in MDCK cysts. Long-term sE-cad treatment induced EMT. sE-cad caused lumen filling by induction of the ERK signaling pathway and triggered EMT through the sustained activation of the AKT pathway. Although it is known that sE-cad induces MMP-9 release and consequent EGFR activation in tumor cells, our results, for the first time, demonstrate that carcinoma cells can induce sE-cad shedding in adjacent epithelial cells, which leads to EGFR activation and the eventual transdifferentiation of the normal epithelial cells.

The prognostic significance of pretreatment serum CEA levels in gastric cancer: a meta-analysis including 14651 patients

BACKGROUND

Carcinoembryonic antigen (CEA) is commonly used as a serum tumor marker in clinical practice; however, its prognostic value for gastric cancer patients remains uncertain. This meta-analysis was performed to assess the prognostic value of CEA and investigate CEA as a tumor marker.

METHODS

PubMed, EMBASE and other databases were searched for potentially eligible studies. Forty-one studies reporting the prognostic effect of pretreatment serum CEA expression in gastric cancer patients were selected. Data on 14651 eligible patients were retrieved for the meta-analysis. Based on the data extracted from the available literature, the hazard ratio (HR) and 95% confidence interval (CI) for an adverse prognosis were estimated for gastric cancer patients with elevated pretreatment serum levels of CEA (CEA+) relative to patients with normal pretreatment CEA levels (CEA-).

RESULTS

The CEA+ patients had a significantly poorer prognosis than the CEA- patients in terms of overall survival (OS: HR 1.716, 95% CI 1.594 - 1.848, P< 0.001), disease-specific survival (DSS: HR 1.940, 95% CI 1.563 - 2.408, P< 0.001), and disease-free survival (DFS: HR 2.275, 95% CI 1.836 - 2.818, P< 0.001). Publication bias and an influence of different cut-off values were not observed (all P> 0.05). In the pooled analyses of multivariate-adjusted HRs, the results suggested that pretreatment serum CEA may be an independent prognostic factor in gastric cancer (OS: HR 1.681, 95% CI 1.425 - 1.982; DSS: HR 1.900, 95% CI 1.441 - 2.505; DFS: HR 2.579, 95% CI 1.935 - 3.436).

CONCLUSION/SIGNIFICANCE

The meta-analysis based on the available literature supported the association of elevated pretreatment serum CEA levels with a poor prognosis for gastric cancer and a nearly doubled risk of mortality in gastric cancer patients. CEA may be an independent prognostic factor for gastric cancer patients and may aid in determining appropriate treatment which may preferentially benefit the CEA+ patients.

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.

E-cadherin and gastric cancer: cause, consequence, and applications

E-cadherin (epithelial-cadherin), encoded by the CDH1 gene, is a transmembrane glycoprotein playing a crucial role in maintaining cell-cell adhesion. E-cadherin has been reported to be a tumor suppressor and to be down regulated in gastric cancer. Besides genetic mutations in CDH1 gene to induce hereditary diffuse gastric cancer (HDGC), epigenetic factors such as DNA hypermethylation also contribute to the reduction of E-cadherin in gastric carcinogenesis. In addition, expression of E-cadherin could be mediated by infectious agents such as H. pylori (Helicobacter pylori). As E-cadherin is vitally involved in signaling pathways modulating cell proliferation, survival, invasion, and migration, dysregulation of E-cadherin leads to dysfunction of gastric epithelial cells and contributes to gastric cancer development. Moreover, changes in its expression could reflect pathological conditions of gastric mucosa, making its role in gastric cancer complicated. In this review, we summarize the functions of E-cadherin and the signaling pathways it regulates. We aim to provide comprehensive perspectives in the molecular mechanism of E-cadherin and its involvement in gastric cancer initiation and progression. We also focus on its applications for early diagnosis, prognosis, and therapy in gastric cancer in order to open new avenues in this field.

Modulation of RTK by sEcad: a putative mechanism for oncogenicity in oropharyngeal SCCs

OBJECTIVE

Heightened levels of sEcad are found in the serum of patients with cancer and correlate with an unfavorable prognosis and later-stages of disease. In this study, we explored whether sEcad is elevated in human OPSCC specimens and FaDu cells. Additionally, we investigated sEcad-EGFR and sEcad-IGF-1R interactions and performed a functional analysis of sEcad in OPSCC cancers.

MATERIALS AND METHODS

sEcad, EGFR, and IGF-1R levels were examined in human OPSCC specimens and cells by immunoblotting. sEcad-EGFR and sEcad-IGF-1R interactions were examined by immunoprecipitation and immunoblot assays. Levels of sEcad on EGFR and IGF-1R pathway components were evaluated by IB. The effects of sEcad on OPSCC proliferation, migration, and invasion were assessed using standard cellular assays.

RESULTS

Statistical analysis demonstrated that sEcad levels were significantly higher in OPSCC primary tumors and cells compared with normal controls. IP studies indicated that sEcad associated with EGFR and IGF-1R, and addition of sEcad resulted in a statistically significant increase in downstream signaling. Finally, cell-based assays demonstrated enhanced sEcad-induced proliferation, migration, and invasion, which was blocked by EGFR and IGF-1R inhibitors.

CONCLUSIONS

These findings suggest that sEcad may play an important role in OPSCC oncogenicity via its interaction and activation of EGFR and IGF-1R.

Positive nuclear expression of KLF8 might be correlated with shorter survival in gastric adenocarcinoma

Krűppel-like factor 8 (KLF8) is important in cell proliferation, epithelial-to-mesenchymal transition, cell migration, and invasion. Gastric adenocarcinoma is among the leading causes of cancer-related death in the world. In this study, the clinicopathologic correlation of KLF8 expression with gastric adenocarcinoma in Taiwan was investigated. The nuclear localization of KLF8 was correlated with advanced stage (P = .008) and 3-year survival rate (P = .043). The nuclear expression of KLF8 was significantly higher in the diffused type of gastric adenocarcinoma compared with the intestinal type (P = .036). Kaplan-Meier analysis results showed that patients with positive nuclear KLF8 had significantly lower overall survival rate compared with those with negative nuclear KLF8 (P = .011). Univariate analysis results indicated that positive nuclear KLF8 expression, advanced stage, and lymph node metastasis are correlated with lower overall survival. Positive nuclear KLF8 might be correlated with lower survival in gastric adenocarcinoma patients and might be an oncogene property in gastric adenocarcinoma carcinogenesis.

Soluble E-cadherin in Systemic Lupus Erythematosus

Objective.

E-cadherin is a potent adherens junction molecule implicated in tissue morphogenesis, epithelial functioning, and immune regulation. Serum levels of soluble E-cadherin (sE-cadherin), an end product of proteolytic cleavage of E-cadherin, is increased in patients with cancer, infections, and inflammation-related diseases. The aim of our study was to measure serum levels of sE-cadherin in systemic lupus erythematosus (SLE) and to determine associations between serum levels of sE-cadherin and markers of inflammation and organ damage in female patients with SLE.

Methods.

Serum levels of sE-cadherin were analyzed by ELISA in 150 female patients with SLE and 31 healthy women. Simple and multiple regression analyses between sE-cadherin levels and disease-related variables were performed in patients with SLE.

Results.

Serum levels of sE-cadherin were elevated in patients with SLE compared with levels in healthy controls. sE-cadherin levels correlated positively with age, disease duration, SLE Collaborating Clinics Damage Index, erythrocyte sedimentation rate (ESR), s-creatinine, cholesterol, triglycerides, interleukin 6, and matrix metalloproteinase-3. In multiple regression analysis, s-creatinine, age, ESR, and triglycerides remained determinants of sE-cadherin. Within the patients with SLE, higher sE-cadherin levels were found only in patients with renal damage, i.e., s-creatinine > 90 μmol/l, glomerular filtration rate < 50 ml/min, or renal involvement ever by SLE.

Conclusion.

Our study demonstrates significantly elevated serum levels of sE-cadherin in women with SLE compared with healthy women. The levels of sE-cadherin were positively correlated to s-creatinine, age, ESR, and triglycerides. Significantly elevated sE-cadherin levels were observed only in patients with renal damage.

Molecular biomarkers in esophageal, gastric, and colorectal adenocarcinoma

Cancers of the esophagus, stomach and colon contribute to a major health burden worldwide and over 20% of all cancer deaths. Biomarkers that should indicate pathogenic process and are measureable in an objective manner for these tumors are rare and not established in the clinical setting. In general biomarkers can be very useful for cancer management as they can improve clinical decision-making regarding diagnosis, surveillance, and therapy. Biomarkers can be different types of molecular entities (such as DNA, RNA or proteins), which can be detected, in different tissues or body fluids. However, more important is the type of biomarker itself, which allows diagnostic, prognostic or predictive analyses for different clinical problems. This review aims to systematically summarize the recent findings of genetic and epigenetic markers for gastrointestinal tumors within the last decade. While many biomarkers seem to be very promising, especially if used as panels, further development is urgently needed to address practical considerations of biomarkers in cancer treatment.

Soluble E-cadherin: a critical oncogene modulating receptor tyrosine kinases, MAPK and PI3K/Akt/mTOR signaling

E-cadherin, a cell-cell adhesion glycoprotein, is frequently downregulated with tumorigenic progression. The extracellular domain of E-cadherin is cleaved by proteases to generate a soluble ectodomain fragment, termed sEcad, which is elevated in the urine or serum of cancer patients. In this study, we explored the functional role of sEcad in the progression of skin squamous cell carcinomas (SCCs). We found that full-length E-cadherin expression was decreased and sEcad increased in human clinical tumor samples as well as in ultraviolet (UV)-induced SCCs in mice. Interestingly, sEcad associated with members of the human epidermal growth factor receptor (HER) and insulin-like growth factor-1 (IGF-1R) family of receptors in human and UV-induced mouse tumors. Moreover, in both E-cadherin-positive (E-cadherin(+)) and -negative (E-cadherin(-)) cells in vitro, sEcad activated downstream mitogen-activated protein (MAP) kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling and enhanced tumor growth, motility and invasion, the latter via activation of matrix metalloproteinase-2 (MMP-2) and MMP-9. To this end, HER, PI3K or MEK inhibitors suppressed sEcad's tumorigenic effects, including proliferation, migration and invasion. Taken together, our data suggest that sEcad contributes to skin carcinogenesis via association with the HER/IGF-1R-family of receptors and subsequent activation of the MAPK and PI3K/Akt/mTOR pathways, thereby implicating sEcad as a putative therapeutic target in cutaneous SCCs.

Establishment of animal model for the analysis of cancer cell metastasis during radiotherapy

Background

Γ-Ionizing radiation (IR) therapy is one of major therapeutic tools in cancer treatment. Nevertheless, γ-IR therapy failed due to occurrence of metastasis, which constitutes a significant obstacle in cancer treatment. The main aim of this investigation was to construct animal model which present metastasis during radiotherapy in a mouse system in vivo and establishes the molecular mechanisms involved.

Materials and methods

The C6L transfectant cell line expressing firefly luciferase (fLuc) was treated with γ-IR, followed by immunoblotting, zymography and invasion assay in vitro. We additionally employed the C6L transfectant cell line to construct xenografts in nude mice, which were irradiated with γ-IR. Irradiated xenograft-containing mice were analyzed via survival curves, measurement of tumor size, and bioluminescence imaging in vivo and ex vivo. Metastatic lesions in organs of mice were further assessed using RT-PCR, H & E staining and immunohistochemistry.

Results

γ-IR treatment of C6L cells induced epithelial-mesenchymal transition (EMT) and increased cell invasion. In irradiated xenograft-containing mice, tumor sizes were decreased dramatically and survival rates extended. Almost all non-irradiated xenograft-containing control mice had died within 4 weeks. However, we also observed luminescence signals in about 22.5% of γ-IR-treated mice. Intestines or lungs of mice displaying luminescence signals contained several lesions, which expressed the fLuc gene and presented histological features of cancer tissues as well as expression of EMT markers.

Conclusions

These findings collectively indicate that occurrences of metastases during γ-IR treatment accompanied induction of EMT markers, including increased MMP activity. Establishment of a murine metastasis model during γ-IR treatment should aid in drug development against cancer metastasis and increase our understanding of the mechanisms underlying the metastatic process.

N-myc downstream regulated gene 1 (NDRG1) promotes metastasis of human scirrhous gastric cancer cells through epithelial mesenchymal transition

Our recent study demonstrated that higher expression of N-myc downregulated gene 1 (NDRG1) is closely correlated with poor prognosis in gastric cancer patients. In this study, we asked whether NDRG1 has pivotal roles in malignant progression including metastasis of gastric cancer cells. By gene expression microarray analysis expression of NDRG1 showed the higher increase among a total of 3691 up-regulated genes in a highly metastatic gastric cancer cell line (58As1) than their parental low metastatic counterpart (HSC-58). The highly metastatic cell lines showed decreased expression of E-cadherin, together with enhanced expression of vimentin and Snail. This decreased expression of E-cadherin was restored by Snail knockdown in highly metastatic cell lines. We next established stable NDRG1 knockdown cell lines (As1/Sic50 and As1/Sic54) from the highly metastatic cell line, and both of these cell lines showed enhanced expression of E-cadherin and decreased expression of vimentin and Snail. And also, E-cadherin promoter-driven luciferase activity was found to be increased by NDRG1 knockdown in the highly metastatic cell line. NDRG1 knockdown in gastric cancer cell showed suppressed invasion of cancer cells into surround tissues, suppressed metastasis to the peritoneum and decreased ascites accumulation in mice with significantly improved survival rates. This is the first study to demonstrate that NDRG1 plays its pivotal role in the malignant progression of gastric cancer through epithelial mesenchymal transition.

Relationships among changes in tongue coating, levels of serum soluble E-cadherin, clinical examination parameters and gastric adenocarcinoma

AIM: To investigate the relationship between serum soluble E-cadherin (sE-cad) levels and changes in tongue coating in patients with gastric adenocarcinoma and healthy controls.

METHODS: This was a case-control study involving 266 gastric adenocarcinoma cases and 252 healthy controls. Serum levels of sE-cad were measured by ELISA. The correlations among serum sE-cad levels, clinical examination parameters and type of tongue coating were analyzed using nonparametric tests.

RESULTS: Serum levels of sE-cad were significantly higher in gastric adenocarcinoma cases than in healthy controls (P < 0.01), in patients before operation than in those after operation (P < 0.05), and in patients with metastasis than in those without metastasis (P < 0.05). The levels of sE-cad were highest in patients with white thick coating, followed by those with white thin coating, yellow thick coating, yellow thin coating and exfoliative coating (P < 0.05), whereas the order in healthy controls was yellow thin coating, yellow thick coating, white thin coating, white thick coating and exfoliative coating (P > 0.05). The proportion of gastric adenocarcinoma cases with abnormal clinical examination parameters was higher than that of healthy controls (P < 0.05). Especially, gastric adenocarcinoma cases with thick and thin coatings and abnormal total protein had higher levels of sE-cad than healthy controls (P < 0.05).

CONCLUSION: The changes in thick and thin coatings and levels of total protein and sE-cad in serum can offer clues for diagnosis and treatment of gastric adenocarcinoma.

Clinical significance of serum levels of soluble E-cadherin in patients with gastric carcinoma

AIM: To measure serum levels of soluble E-cadherin (sE-cadherin) in patients with gastric cancer and to evaluate the relationship of serum levels of sE-cadherin with tumor clinicopathological features and patient survival.

METHODS: Peripheral blood samples were collected from 127 gastric cancer patients and 31 healthy controls from March 2003 to September 2004. Serum levels of sE-cadherin were measured using double-antibody sandwich enzyme-linked immunosorbent assay. The clinical pathological data and survive data for all patients were recorded.

RESULTS: Serum levels of sE-cadherin were significantly higher in patients with gastric cancer than in healthy controls (43.83 μg/L ± 15.77 μg/L vs 17.17 μg/L ± 5.38 μg/L, P = 0.000, t = 8.34). Serum levels of sE-cadherin were closely associated with tumor differentiation, depth of invasion and lymph node metastasis (all P < 0.05). Patients with lower levels of serum sE-cadherin had significant survival advantage over those with higher levels of serum sE-cadherin (P < 0.001), and such survival advantage was independent of depth of invasion, lymph node metastasis and tumor differentiation.

CONCLUSION: sE-cadherin may serve as a potential biological marker for the diagnosis and prognosis of gastric cancer.

Prognostic value of colorectal cancer biomarkers

Despite the large amount of data in cancer biology and many studies into the likely survival of colorectal cancer (CRC) patients, knowledge regarding the issue of CRC prognostic biomarkers remains poor. The Tumor-Node-Metastasis (TNM) staging system continues to be the most powerful and reliable predictor of the clinical outcome of CRC patients. The exponential increase of knowledge in the field of molecular genetics has lead to the identification of specific alterations involved in the malignant progression. Many of these genetic alterations were proposed as biomarkers which could be used in clinical practice to estimate CRC prognosis. Recently there has been an explosive increase in the number of putative biomarkers able to predict the response to specific adjuvant treatment. In this review we explore and summarize data concerning prognostic and predictive biomarkers and we attempt to shed light on recent research that could lead to the emergence of new biomarkers in CRC.

Genomic and genetic alterations influence the progression of gastric cancer

Gastric cancer is one of the leading causes of cancer-related deaths worldwide, although the incidence has gradually decreased in many Western countries. Two main gastric cancer histotypes, intestinal and diffuse, are recognised. Although most of the described genetic alterations have been observed in both types, different genetic pathways have been hypothesized. Genetic and epigenetic events, including 1q loss of heterozygosity (LOH), microsatellite instability and hypermethylation, have mostly been reported in intestinal-type gastric carcinoma and its precursor lesions, whereas 17p LOH, mutation or loss of E-cadherin are more often implicated in the development of diffuse-type gastric cancer. In this review, we summarize the sometimes contradictory findings regarding those markers which influence the progression of gastric adenocarcinoma.

Serum soluble E-cadherin is a potential prognostic marker in esophageal squamous cell carcinoma

E-cadherin is a well-documented tumor suppressor with downregulated expression in many cancer types. Upon proteolytic cleavage, a soluble form of 80-kDa degradation fragment, known as soluble E-cadherin (s-Ecad), is present in circulation; its level in sera of cancer patients is significantly associated with metastasis, recurrence, and prognosis in some malignancies. The present study investigated the association of s-Ecad with clinicopathological characteristics of patients with esophageal squamous cell carcinoma (ESCC) and its prognostic significance. A cohort of 97 patients who underwent surgery alone (n= 56) or neoadjuvant chemoradiation therapy and surgery (CRT) (n= 41) was recruited for this study. Serum samples were collected at operation (surgery group) and pre- and post-CRT treatment (CRT group) for measurement of s-Ecad protein by enzyme linked immunosorbent assay. Serum s-Ecad levels were correlated with clinicopathological parameters as well as survival. Univariate analysis showed no significant relationship between serum s-Ecad level and clinicopathological parameters for all sets of samples. Survival analysis showed that in patients who had surgical resection only, those with s-Ecad levels equal to or below the median value survived significantly longer than those with levels above the median (median survival 25.6 vs. 14.1 months, P= 0.012). Multivariate analysis showed that pathological N stage, M stage, R category, and serum s-Ecad level were significant independent prognostic factors for ESCC patients who underwent surgery only. The hazard ratio for s-Ecad was 1.104 (95% CI: 1.026-1.187) and P= 0.008. Serum s-Ecad was detected in ESCC patients and its potential as an independent prognostic marker requires further investigation.

Soluble adhesion molecules E-cadherin, intercellular adhesion molecule-1, and E-selectin as lung cancer biomarkers

BACKGROUND

Altered levels of circulating adhesion molecules found in several carcinomas, including lung cancer, reflect local loss of diffusion barriers and tumor volume and can be potentially used as biomarkers. In the present study, we investigated the role of soluble E-cadherin (sE-cad), soluble intercellular adhesion molecule-1 (sICAM-1), and soluble E-selectin (sE-sel) as biomarkers in lung cancer.

METHODS

Sixty-two patients with recently diagnosed lung cancer, 42 with small cell lung cancer (SCLC), and 20 with non-small cell lung cancer (NSCLC), as well as 29 healthy volunteers were enrolled. Blood samples were collected at the time of diagnosis and measurement of soluble adhesion molecules in the serum samples was performed by enzyme-linked immunoassay using monoclonal antibodies against E-cadherin, E-selectin, and ICAM-1.

RESULTS

Serum levels of sE-cad, sE-sel, and sICAM-1 in both SCLC and NSCLC were significantly elevated compared with control subjects (P < .001). In addition, patients with SCLC or NSCLC with distant metastasis had a marked increase of sE-Cad (P < .001), but no such correlation with sE-sel and sICAM-1 was found.

CONCLUSIONS

Our findings suggest that sE-cad, sE-sel, and sICAM-1 have an adjunctive diagnostic role in lung cancer. Furthermore, sE-cad may also have a prognostic role and could be a useful biomarker in the prediction of lung cancer outcome.

Epithelial-mesenchymal transition in cancer development and its clinical significance

The epithelial-mesenchymal transition (EMT) plays a critical role in embryonic development. EMT is also involved in cancer progression and metastasis and it is probable that a common molecular mechanism is shared by these processes. Cancer cells undergoing EMT can acquire invasive properties and enter the surrounding stroma, resulting in the creation of a favorable microenvironment for cancer progression and metastasis. Furthermore, the acquisition of EMT features has been associated with chemoresistance which could give rise to recurrence and metastasis after standard chemotherapeutic treatment. Thus, EMT could be closely involved in carcinogenesis, invasion, metastasis, recurrence, and chemoresistance. Research into EMT and its role in cancer pathogenesis has progressed rapidly and it is now hypothesized that novel concepts such as cancer stem cells and microRNA could be involved in EMT. However, the involvement of EMT varies greatly among cancer types, and much remains to be learned. In this review, we present recent findings regarding the involvement of EMT in cancer progression and metastasis and provide a perspective from clinical and translational viewpoints.

Serum macrophage migration-inhibitory factor as a diagnostic and prognostic biomarker for gastric cancer

BACKGROUND

This study aimed to determine the potential diagnostic value of migration-inhibitory factor (MIF) for gastric cancer in patients presenting with dyspepsia and its prognostic value for gastric cancer.

METHODS

A cohort of 97 patients with histologically confirmed gastric adenocarcinoma and 222 patients with dyspepsia were recruited. Enzyme-linked immunosorbent assay was used to measure serum MIF and carcinoembryonic antigen (CEA).

RESULTS

The serum MIF concentrations were 6554.0 +/- 204.1 pg/mL and 1453.7 +/- 79.9 pg/mL, respectively, in gastric cancer patients and dyspeptic patients (P < .001). Serum MIF levels increased with the advancing gastric pathologies (P < .001). With the cutoff value of 3230 pg/mL, serum MIF had sensitivity, specificity, and accuracy of 83.5%, 92.3%, and 89.7%, respectively, in diagnosing gastric cancer, whereas the rates were 60.8%, 83.3%, and 76.5%, respectively, for serum CEA. Gastric cancer patients with serum MIF levels above 6600 pg/mL had a lower 5-year survival rate than those with serum MIF level below that level (P = .012). Higher serum CEA levels were also associated with poor survival. The prediction for 5-year survival was even better (P = .0001), using a combination of serum MIF and CEA.

CONCLUSIONS

Serum MIF level, which correlates with gastric MIF expression, is a better molecular marker than CEA in diagnosing gastric cancer in patients presenting with dyspepsia. A combination of serum MIF and CEA predicts 5-year survival better than the individual test.

Tumor response to combination celecoxib and erlotinib therapy in non-small cell lung cancer is associated with a low baseline matrix metalloproteinase-9 and a decline in serum-soluble E-cadherin

INTRODUCTION

Cyclooxygenase-2 overexpression may mediate resistance to epidermal growth factor receptor tyrosine kinase inhibition through prostaglandin E2-dependent promotion of epithelial to mesenchymal transition (EMT). Suppression of epithelial markers, such as E-cadherin, can lead to resistance to erlotinib. Prostaglandin E2 down-regulates E-cadherin expression by up-regulating transcriptional repressors, including ZEB1 and Snail. Furthermore, E-cadherin can be modulated by matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs), promoting tumor invasion and metastasis. Markers of EMT and tumor invasion were evaluated in patient serum from a phase I clinical trial investigating the combination of celecoxib and erlotinib in non-small cell lung cancer (NSCLC) patients.

METHODS

Samples from 22 subjects were evaluated. Soluble E-cadherin (sEC) was evaluated by enzyme linked immunosorbent assay in patient serum at baseline, week 4, and week 8 of treatment. Other markers of EMT and angiogenesis were evaluated by enzyme linked immunosorbent assay, including MMP-9, TIMP-1, and CCL15.

RESULTS

Serum sEC, MMP-9, TIMP-1, and CCL15 levels were determined at baseline and week 8. Patients with a partial response to therapy had a significant decrease in sEC, TIMP-1, and CCL15 at week 8. In patients who responded to the combination therapy, baseline MMP-9 was significantly lower compared with nonresponders (p = 0.006).

CONCLUSIONS

sEC, MMP-9, TIMP-1, and CCL15 levels correlate with response to combination therapy with erlotinib and celecoxib in patients with NSCLC. A randomized phase II trial is planned comparing erlotinib and celecoxib with erlotinib plus placebo in advanced NSCLC. This study will prospectively assess these and other biomarkers in serum and tumor tissue.

ADAM10-mediated E-cadherin release is regulated by proinflammatory cytokines and modulates keratinocyte cohesion in eczematous dermatitis

Acute eczema is an inflammatory skin disease characterized by the formation of small intraepidermal blisters, reduction of the adhesion molecule E-cadherin from the keratinocyte surface, and impaired keratinocyte cohesion. Here, we reveal that the disintegrin and metalloprotease ADAM10 is critically involved in regulating E-cadherin cell-surface expression in cultured primary human keratinocytes and in diseased human skin. Proinflammatory cytokines, transforming growth factor-beta, and lipopolysaccharide led to increased release of soluble E-cadherin by activating mitogen-activated protein kinase signaling in cultured keratinocytes. Moreover, these stimuli decreased the amount of pro-ADAM10 and increased the level of the active protease, leading to loss of E-cadherin from the cell surface and decreased keratinocyte cohesion. In situ examination and immunoblot analyses of E-cadherin and ADAM10 expression in lesional skin of eczema revealed that the reduction of E-cadherin expression in areas of blister formation closely correlated with increased level of ADAM10 expression and elevated E-cadherin shedding. Our data suggest that ADAM10-mediated E-cadherin proteolysis leads to the impaired cohesion of keratinocytes observed in eczematous dermatitis and provide previously unreported insights into the understanding of the molecular mechanisms involved in inflammatory diseases with loss in epithelial integrity.

Soluble cadherins as cancer biomarkers

Molecular activities, regulating a balanced tissue organisation, are frequently disturbed during cancer progression. These include protein ectodomain shedding, a post-translational process that substantially changes the functional properties of the substrate protein. In comparison with normal epithelia, cancer cells almost invariably show diminished cadherin-mediated intercellular adhesion. This review will address cadherin ectodomain shedding and its functional consequence in normal physiology and in the tumor environment. Soluble cadherin fragments may retain specific biological activities during cancer cell invasion, angiogenesis and perineural invasion. When diffusion barriers disappear, soluble cadherins are detected in sera from cancer patients. Soluble N-(neural) cadherin may represent a novel diagnosis/prognostic biomarker showing a correlation with PSA in sera of prostate cancer patients. Furthermore, therapeutic monitoring in pancreas adenomacarcinoma revealed a correlation between circulating soluble N-cadherin and CA 19-9. A better understanding of cadherin regulation in cancer progression will likely increase our awareness of the importance of the combinatorial signals that regulate tissue integrity and eventually result in the identification of new therapeutics targeting cadherins.

Molecular markers for gastric adenocarcinoma: an update

Gastric cancer is the second most common cancer worldwide. Treatment of localized gastric cancer relies primarily on surgical intervention, although growing evidence suggests that the addition of chemoradiation may improve disease-free intervals and overall survival. In this regard, the current high rates of recurrence and subsequent poor survival have prompted an ever-increasing use of multimodal strategies, even for early-stage disease. However, these therapies are often limited by debilitating toxicities and varying degrees of response efficacy. As a result, pharmacogenomics, the study of specific genetic and molecular signatures that may be predictive of treatment outcomes, has gained considerable interest. For example, studies have demonstrated that the expression of enzymes involved in the metabolism or conjugation of commonly used chemotherapy agents, such as fluoropyrimidines and cisplatin, can serve as surrogate markers predictive of chemotherapy response. Polymorphisms in the genes encoding these enzymes have also been identified and may further account for altered expression patterns, resulting in varied clinical responses. Future work is necessary to further refine the list of molecular genetic markers and to identify novel markers for prognostic and predictive purposes. Technologies such as microarray analysis may be useful in identifying new molecular genetic markers, and further work may determine whether these markers can be employed to help stratify patients into different multimodal treatment regimens.

Soluble N-cadherin in human biological fluids

Classical cadherins such as E-, P- and N-cadherin are transmembrane proteins that mediate cell-cell adhesion, and are important in embryogenesis, maintenance of tissue integrity and cancer. Proteolytic shedding of the extracellular domain results in the generation of soluble E-, P- or N-cadherin ectodomains. Circulating soluble E- and P-cadherin have been described in the serum, and elevated levels were detected in cancer patients when compared with healthy persons. Here we report the presence of soluble N-cadherin, a 90-kD protein fragment, in the serum of both healthy persons and cancer patients, using a direct ELISA and immunoprecipitation. A correlation was found between prostate specific antigen and soluble N-cadherin, and significantly elevated levels were detected in prostate cancer follow-up patients. The N-cadherin protein is neo-expressed by carcinomas of the prostate, and is responsible for epithelial to fibroblastic transition. This is reflected by the higher concentrations of soluble N-cadherin in prostate cancer patients than in healthy persons.

CDH1 (E-cadherin) in testicular germ cell neoplasia: suppressed translation of mRNA in pre-invasive carcinoma in situ but increased protein levels in advanced tumours

E-cadherin (CDH1) is a transmembrane glycoprotein involved in cellular adhesion. In our recent microarray studies of testicular germ cell tumours (TGCTs) and the common precursor carcinoma in situ (CIS), CDH1 mRNA was highly expressed in CIS and embryonal carcinoma. It has previously been reported that the CDH1 protein is not expressed in CIS. To resolve the discrepancy, we performed a detailed analysis of the expression of CDH1 mRNA and protein in a series of normal and neoplastic testes. High expression of CDH1 mRNA in CIS was confirmed by real-time PCR and in situ hybridisation. At the protein level, however, CDH1 was only detected with one of three tested antibodies, but Western blotting analysis with this antibody showed additional bands, suggesting unspecific staining. The levels of a CDH1 protein fragment in serum samples from 58 patients with TGCTs were analysed by ELISA; we found significantly higher levels in patients with advanced disease (stage II/III) when compared to healthy individuals and patients with stage I TGCT. In conclusion, despite high mRNA levels, the CDH1 protein is not expressed in CIS, suggesting translational suppression of CDH1 protein expression. CDH1 serum levels may be a serological marker for staging of TGCT patients.

Breaking up the tie: Disintegrin-like metalloproteinases as regulators of cell migration in inflammation and invasion

Cell adhesion and cell migration are essential for a variety of important events in both embryonic development and in the adult organism. Cell adhesion molecules (CAM) like selectins, immunoglobulin superfamily members, integrins, and cadherins undergo diverse mechanisms of regulation. Dysregulation of adhesion can lead to pathological processes, including inflammatory diseases or tumor metastasis either by disrupting the normal anchorage, thereby altering cell movement and regulatory signalling, or by promoting inappropriate temporal and spatial adhesion. An increasing body of evidence has emerged showing that members of the a disintegrin and metalloproteinase (ADAM) family critically contribute to the regulation of CAM functions. While the disintegrin domain can interact with integrins and mediate adhesion, the metalloproteinase domain can mediate anti-adhesive functions by cleaving the membrane bound adhesion molecules. This "shedding" process leads to the release of often still functional soluble ectodomains and can additionally influence intracellular cell signalling pathways. Several soluble CAMs have been detected in vitro and in vivo. Some of them are strongly increased in inflammatory diseases or in the serum of cancer patients. Therefore the level of soluble CAMs but also the expression of the metalloproteinases responsible for their release might provide prognostic information. It could also be useful for monitoring malignant disease stages and for evaluating the effectiveness of various therapeutic approaches. Moreover, metalloproteases of the ADAM family are emerging as promising targets for new therapeutic options.

Molecular screening of gastric cancer by proteome analysis

Gastric cancer affects annually more than 800,000 individuals worldwide and remains a challenge for clinicians and oncologists. Most patients with gastric cancer are diagnosed in advanced stages, when a curative resection is impossible, which leads to an overall poor prognosis. Finding new diagnostic and treatment procedures is of paramount importance to improve patient prognosis, which will be improved most dramatically by techniques that allow the detection of gastric cancer in its early stages. So far the value of conventional tumour markers such as Ca72-4 or carcinoembryonic antigen is limited, and even markers developed from molecular biological studies on the carcinogenesis of gastric cancer, such as E-cadherin and others, have not proved to be of adequate sensitivity and specificity to allow the early detection of gastric cancer. With the development of innovative diagnostic tools, such as proteome analysis, new biomarkers may be identified that may allow early diagnosis and thus screening for gastric cancer, particularly in at-risk patient populations. Recent studies have indicated that these biomarkers may be derived from the tumour itself or reflect a specific metabolic or immunological response to cancer that can be used to find gastric cancer patients at an early and putatively curative stage of the disease.

Titration of serum p53 antibodies in patients with gastric cancer: a single-institute study of 40 patients

BACKGROUND

Alterations of the p53 tumor suppressor gene are the most commonly observed genetic abnormalities in many different types of human malignancies. The accumulation of mutant p53 often leads to the production of p53 antibody (p53-Ab) in the sera of patients with various cancers. To evaluate the clinical implications of serum p53-Abs in patients with gastric cancer, we compared p53-Abs with conventional tumor markers such as carcinoembryonic antigen (CEA) and carbohydrate antigen (CA)19-9.

METHODS

Serum samples were obtained preoperatively from 40 patients with histologically confirmed gastric adenocarcinoma, including 28 (70%) patients in stage Ia. The serum p53-Abs were assessed by enzyme-linked immunosorbent assay, using a new version of a highly specific, quantitative p53-Abs Kit (MESACUP Kit II).

RESULTS

p53-Abs were detected in 6 (15%) of 40 patients with gastric cancer, including 3 patients with early gastric cancer. Seven (17.5%) of the 40 patients were positive for CEA in serum. However, none of 7 patients with high CEA levels were positive for p53-Abs. No significant correlation of p53-Abs with patient age, sex, pathological parameters, tumor markers such as CEA and CA19-9, or poor survival (P = 0.116) was observed.

CONCLUSION

Although we employed the latest version of the p53-Abs Kit, the sensitivity of serum p53-Ab in gastric cancer patients was relatively low. No correlation was found between the presence of p53-Ab and the staging of cancer or survival. However, serum p53-Ab was detectable in patients with gastric cancer even in the early stages of disease. In addition, it may be independent of CEA and CA19-9.

E-cadherin in gastric cancer

Cadherin is an adhesion molecule and a superfamily of calcium-mediated membrane glycoproteins. E-cadherin is the prototype of the class E-cadherin that links to catenins to form the cytoskeleton. Recent evidence has shown that E-cadherin not only acts as an adhesive, but also plays important roles in growth development and carcinogenesis. It has been recently viewed as an invasion as well as a growth suppressor gene. This review summarizes the recent discoveries on E-cadherin and its role in gastric cancer. In particular, our work on E-cadherin in gastric cancer, including its relation with Helicobacter pylori and clinical applications, are described in detail.

Elevated Serum Levels of Soluble E-Cadherin in Patients with Primary Sjogren's Syndrome

The aim of this study was to investigate serum levels of soluble E-cadherin (sE-cadherin) in relation to lymphocytic organization and to characterize the expression of E-cadherin and integrin alphaEbeta7/CD103 in salivary gland epithelium of patients with Sjögren's syndrome (SS). Serum levels of sE-cadherin were significantly increased in SS compared to non-SS and nonsignificantly in germinal centre (GC)+ compared to GC- patients. Membrane-bound E-cadherin was detected on the majority of acinar and ductal epithelial cells in both SS and non-SS. alphaEbeta7/CD103-positive cells were found scattered in focal infiltrates and GC, and in small clusters close to ductal and acinar epithelium at an increased level in SS compared to non-SS. Interestingly, E-cadherin-positive cells were detected randomly dispersed in focal lymphocytic infiltrates in 10/21 patients. By double-labelling, the cells with the E-cadherin-positive component were identified as CD68(+) macrophages. Elevated serum levels of sE-cadherin indicate an increased epithelial cell turnover and shedding, and sE-cadherin deserves further analysis as a potential diagnostic tool for SS.

The E-cadherin–β-catenin complex and its implication in lung cancer progression and prognosis

The E-cadherin–β−catenin complex plays a pivotal role in epithelial cell–cell adhesion and in the maintenance of differentiated adult epithelia. Perturbation of its expression or function is widely involved in tumor progression and metastasis. Recent years have seen a rapid expansion in the understanding of the biology and the clinical relevance of the E-cadherin adhesion complex in human lung cancer. During human lung cancer progression genomic, transcriptionnal and post-transcriptionnal alterations of the E-cadherin–β-catenin adhesion system are implicated and comprise deletion of the chromosomic region 3p21 that comprise the locus of the gene encoding β-catenin, transcriptionnal downregulation of E-cadherin, cytoplasmic redistribution, phosphorylation of both proteins and proteolysis of E-cadherin. E-cadherin-inactivating mutations and oncogenic-activating mutation of β-catenin are not reported.