Soluble E-cadherin fragments increased in circulation of cancer patients

Study on the Interactions Between Cisplatin and Cadherin by Fluorescence Spectrometry and Atomic Force Microscopy

Cisplatin is an important platinum drug in cancer chemotherapy in clinical practice. It is well established that the main target of cisplatin is nuclear DNA. However, recent studies have demonstrated that platinum drugs may act on some important functional proteins in the human body. E-cadherin is a newly discovered glycoprotein that has been regarded as an important sign of the occurrence and development of some tumors. This study examines the interactions between cisplatin and E-cadherin by fluorescence spectrometry and atomic force microscopy (AFM). The fluorescence spectrometry results indicated that cisplatin can efficiently quench the fluorescence of E-cadherin. The calculated binding constant Kb was 3.20 × 106 (25 ℃), 1.36 × 106(31 ℃), and 8.22 × 105 L mol-1 (37 ℃). These results reveal that the fluorescence quenching effect of cisplatin on E-cadherin is static quenching. The obtained thermodynamic parameters ΔH < 0, ΔS < 0, and ΔG < 0, indicate that the binding of cisplatin on E-cadherin is a spontaneous process dominated by hydrogen bonds and Van der Waals forces. The AFM results revealed that E-cadherins are interlaced with each other to form a spherical-chain structure. The addition of cisplatin can significantly disrupt the interlaced structure of the E-cadherin molecules.

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.

FOXN3 inhibits the progression of ovarian cancer through negatively regulating the expression of RPS15A

Ovarian cancer is the second most common cause of gynecological cancer death and has a high recurrence rate. FOXN3, a transcription inhibitor belonging to FOX family, has anti-tumor effects on several cancers. Bioinformatics analysis revealed that the expression of FOXN3 was downregulated in ovarian cancer specimens. However, the role of FOXN3 in ovarian cancer remains unclear. Herein, we investigated the role of FOXN3 in ovarian cancer using OVCAR3 and A2780 cells. Flow cytometry and CCK-8 analysis showed that overexpression of FOXN3 inhibited the proliferation and cell cycle progression of OVCAR3 cells. Cell invasion and migration abilities were decreased by FOXN3 according to transwell and wound healing assays. The suppression of FOXN3 on angiogenesis in OVCAR3 cells was evidenced by reduced vessel formation and VEGFA protein expression. Taken together, FOXN3 had an inhibitory effect on the proliferation, migration, invasion and angiogenesis of OVCAR3 cells, while its knockdown exhibited an opposite effect in A2780 cells. By inoculation of FOXN3-overexpressing cells into nude mice, tumorigenesis assay demonstrated that FOXN3 could delay the growth of ovarian cancer cells in vivo. The interaction between FOXN3 and RPS15A was preliminarily explored via dual-luciferases assay and ChIP. FOXN3 was confirmed to bind to the promoter (at - 1588/- 1581 and - 1476/- 1467) of gene RPS15A and inhibit its transcriptional expression. We further found that overexpression of RPS15A diminished the inhibition of FOXN3 on ovarian cancer cell malignant behaviors. These findings indicate that FOXN3 negatively regulates the expression of RPS15A and thus suppresses the progression of ovarian cancer.

Aircraft noise exposure drives the activation of white blood cells and induces microvascular dysfunction in mice

Epidemiological studies showed that traffic noise has a dose-dependent association with increased cardiovascular morbidity and mortality. Whether microvascular dysfunction contributes significantly to the cardiovascular health effects by noise exposure remains to be established. The connection of inflammation and immune cell interaction with microvascular damage and functional impairment is also not well characterized. Male C57BL/6J mice or gp91phox^−/y mice with genetic deletion of the phagocytic NADPH oxidase catalytic subunit (gp91phox or NOX-2) were used at the age of 8 weeks, randomly instrumented with dorsal skinfold chambers and exposed or not exposed to aircraft noise for 4 days. Proteomic analysis (using mass spectrometry) revealed a pro-inflammatory phenotype induced by noise exposure that was less pronounced in noise-exposed gp91phox^−/y mice. Using in vivo fluorescence microscopy, we found a higher number of adhesive leukocytes in noise-exposed wild type mice. Dorsal microvascular diameter (by trend), red blood cell velocity, and segmental blood flow were also decreased by noise exposure indicating microvascular constriction. All adverse effects on functional parameters were normalized or improved at least by trend in noise-exposed gp91phox^−/y mice. Noise exposure also induced endothelial dysfunction in cerebral microvessels, which was associated with higher oxidative stress burden and inflammation, as measured using video microscopy. We here establish a link between a pro-inflammatory phenotype of plasma, activation of circulating leukocytes and microvascular dysfunction in mice exposed to aircraft noise. The phagocytic NADPH oxidase was identified as a central player in the underlying pathophysiological mechanisms.

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Noise exposure induces a pro-thrombo-inflammatory phenotype in mouse plasma.

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Aircraft noise increases leukocyte-endothelium interactions in dorsal microvessels.

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Noise decreases segmental blood flow/red blood cell velocity in dorsal microvessels.

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Noise increases cerebral microvascular dysfunction and oxidative stress.

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Nox2 deficiency (gp91phox^-/y) improves noise-induced adverse effects.

Ultrasound-Based Molecular Imaging of Tumors with PTPmu Biomarker-Targeted Nanobubble Contrast Agents

Ultrasound imaging is a widely used, readily accessible and safe imaging modality. Molecularly-targeted microbubble- and nanobubble-based contrast agents used in conjunction with ultrasound imaging expand the utility of this modality by specifically targeting and detecting biomarkers associated with different pathologies including cancer. In this study, nanobubbles directed to a cancer biomarker derived from the Receptor Protein Tyrosine Phosphatase mu, PTPmu, were evaluated alongside non-targeted nanobubbles using contrast enhanced ultrasound both in vitro and in vivo in mice. In vitro resonant mass and clinical ultrasound measurements showed gas-core, lipid-shelled nanobubbles conjugated to either a PTPmu-directed peptide or a Scrambled control peptide were equivalent. Mice with heterotopic human tumors expressing the PTPmu-biomarker were injected with PTPmu-targeted or control nanobubbles and dynamic contrast-enhanced ultrasound was performed. Tumor enhancement was more rapid and greater with PTPmu-targeted nanobubbles compared to the non-targeted control nanobubbles. Peak tumor enhancement by the PTPmu-targeted nanobubbles occurred within five minutes of contrast injection and was more than 35% higher than the Scrambled nanobubble signal for the subsequent two minutes. At later time points, the signal in tumors remained higher with PTPmu-targeted nanobubbles demonstrating that PTPmu-targeted nanobubbles recognize tumors using molecular ultrasound imaging and may be useful for diagnostic and therapeutic purposes.

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.

A novel FRET peptide assay reveals efficient Helicobacter pylori HtrA inhibition through zinc and copper binding

Helicobacter pylori (H. pylori) secretes the chaperone and serine protease high temperature requirement A (HtrA) that cleaves gastric epithelial cell surface proteins to disrupt the epithelial integrity and barrier function. First inhibitory lead structures have demonstrated the essential role of HtrA in H. pylori physiology and pathogenesis. Comprehensive drug discovery techniques allowing high-throughput screening are now required to develop effective compounds. Here, we designed a novel fluorescence resonance energy transfer (FRET) peptide derived from a gel-based label-free proteomic approach (direct in-gel profiling of protease specificity) as a valuable substrate for H. pylori HtrA. Since serine proteases are often sensitive to metal ions, we investigated the influence of different divalent ions on the activity of HtrA. We identified Zn⁺⁺ and Cu⁺⁺ ions as inhibitors of H. pylori HtrA activity, as monitored by in vitro cleavage experiments using casein or E-cadherin as substrates and in the FRET peptide assay. Putative binding sites for Zn⁺⁺ and Cu⁺⁺ were then analyzed in thermal shift and microscale thermophoresis assays. The findings of this study will contribute to the development of novel metal ion-dependent protease inhibitors, which might help to fight bacterial infections.

Urine E-cadherin: A Marker for Early Detection of Kidney Injury in Diabetic Patients

Diabetic nephropathy (DN) is the main reason for end-stage renal disease. Microalbuminuria as the non-invasive available diagnosis marker lacks specificity and gives high false positive rates. To identify and validate biomarkers for DN, we used in the present study urine samples from four patient groups: diabetes without nephropathy, diabetes with microalbuminuria, diabetes with macroalbuminuria and proteinuria without diabetes. For the longitudinal validation, we recruited 563 diabetic patients and collected 1363 urine samples with the clinical data during a follow-up of 6 years. Comparative urinary proteomics identified four proteins Apolipoprotein A-I (APOA1), Beta-2-microglobulin (B2M), E-cadherin (CDH1) and Lithostathine-1-alpha (REG1A), which differentiated with high statistical strength (p < 0.05) between DN patients and the other groups. Label-free mass spectrometric quantification of the candidates confirmed the discriminatory value of E-cadherin and Lithostathine-1-alpha (p < 0.05). Immunological validation highlighted E-cadherin as the only marker able to differentiate significantly between the different DN stages with an area under the curve (AUC) of 0.85 (95%-CI: [0.72, 0.97]). The analysis of the samples from the longitudinal study confirmed the prognostic value of E-cadherin, the critical increase in urinary E-cadherin level was measured 20 ± 12.5 months before the onset of microalbuminuria and correlated significantly (p < 0.05) with the glomerular filtration rate measured by estimated glomerular filtration rate (eGFR).

E-Cadherin Protein as a Potential Marker for Gastric Cancer and Its Association with Helicobacter Pylori- Induced Gastritis and Gastric Ulcer

BACKGROUND

Gastric cancer is still the main health threat being the third leading cause of deaths from cancers in the world. The major risk behind the gastric cancer is that it remains asymptomatic in the early stages and in (97%) cases it metastasizes to other organs. Gastric cancer is a multifactorial disease in which Helicobacter pylori (H. pylori) has been known as a risk factor. However, patients with gastritis, especially atrophic gastritis and gastric ulcer have been shown to be at an increased risk for developing gastric cancer.

METHODS

This study included measuring the serum levels of E-Cadherin protein, carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA) in 30 patients diagnosed with gastritis, 20 gastric ulcer patients, 20 gastric cancer patients and in 20 healthy volunteers serving as the control group.

RESULTS

Infection with H. pylori was diagnosed by serology (IgA and IgG antibodies) as well as by rapid urease test (RUT) and histology. The results showed that 50 (71.4%) of the patients were positive for H. pylori. Levels of E-Cadherin were increased significantly in all patients in comparison to the control group with a large significant increase in the gastric cancer group. The levels of E-Cadherin were also significantly increased in H. pylori infected patients compared to H. pylori negative patients. A non-significant difference in the levels of CA19-9 and CEA was observed in all patients in comparison to healthy controls.

CONCLUSION

This study concluded that serum E-Cadherin could be considered as a potential marker in diagnosis of gastric cancer.

A toolkit for studying cell surface shedding of diverse transmembrane receptors

Proteolysis of transmembrane receptors is a critical cellular communication mechanism dysregulated in disease, yet decoding proteolytic regulation mechanisms of hundreds of shed receptors is hindered by difficulties controlling stimuli and unknown fates of cleavage products. Notch proteolytic regulation is a notable exception, where intercellular forces drive exposure of a cryptic protease site within a juxtamembrane proteolytic switch domain to activate transcriptional programs. We created a Synthetic Notch Assay for Proteolytic Switches (SNAPS) that exploits the modularity and unequivocal input/response of Notch proteolysis to screen surface receptors for other putative proteolytic switches. We identify several new proteolytic switches among receptors with structural homology to Notch. We demonstrate SNAPS can detect shedding in chimeras of diverse cell surface receptors, leading to new, testable hypotheses. Finally, we establish the assay can be used to measure modulation of proteolysis by potential therapeutics and offer new mechanistic insights into how DECMA-1 disrupts cell adhesion.

Adhesion molecules and pancreatitis

Acute and chronic pancreatitises are gastrointestinal inflammatory diseases, the incidence of which is increasing worldwide. Most (~ 80%) acute pancreatitis (AP) patients have mild disease, and about 20% have severe disease, which causes multiple organ failure and has a high mortality rate. Chronic pancreatitis (CP) is characterized by chronic inflammation and destruction of normal pancreatic parenchyma, which leads to loss of exocrine and endocrine tissues. Patients with CP also have a higher incidence of pancreatic ductal adenocarcinoma. Although a number of factors are associated with the development and progression of AP and CP, the underlying mechanism is unclear. Adhesion molecules play important roles in cell migration, proliferation, and signal transduction, as well as in development and tissue repair. Loosening of cell-cell adhesion between pancreatic acinar cells and/or endothelial cells increases solute permeability, resulting in interstitial edema, which promotes inflammatory cell migration and disrupts tissue structure. Oxidative stress, which is one of the important pathogenesis of pancreatitis, leads to upregulation of adhesion molecules. Soluble adhesion molecules are reportedly involved in AP. In this review, we focus on the roles of tight junctions (occludin, tricellulin, claudin, junctional adhesion molecule, and zonula occludin), adherens junctions (E-cadherin and p120-, α-, and β-catenin), and other adhesion molecules (selectin and intercellular adhesion molecules) in the progression of AP and CP. Maintaining the normal function of adhesion molecules and preventing their abnormal activation maintain the structure of the pancreas and prevent the development of pancreatitis.

Targeting Chemokines and Chemokine Receptors in Melanoma and Other Cancers

The tumor microenvironment is highly heterogeneous. It is composed of a diverse array of immune cells that are recruited continuously into lesions. They are guided into the tumor through interactions between chemokines and their receptors. A variety of chemokine receptors are expressed on the surface of both tumor and immune cells rendering them sensitive to multiple stimuli that can subsequently influence their migration and function. These features significantly impact tumor fate and are critical in melanoma control and progression. Indeed, particular chemokine receptors expressed on tumor and immune cells are strongly associated with patient prognosis. Thus, potential targeting of chemokine receptors is highly attractive as a means to quench or eliminate unconstrained tumor cell growth.

Invasion-Related Factors as Potential Diagnostic and Therapeutic Targets in Oral Squamous Cell Carcinoma-A Review

It is well recognized that the presence of cervical lymph node metastasis is the most important prognostic factor in oral squamous cell carcinoma (OSCC). In solid epithelial cancer, the first step during the process of metastasis is the invasion of cancer cells into the underlying stroma, breaching the basement membrane (BM)—the natural barrier between epithelium and the underlying extracellular matrix (ECM). The ability to invade and metastasize is a key hallmark of cancer progression, and the most complicated and least understood. These topics continue to be very active fields of cancer research. A number of processes, factors, and signaling pathways are involved in regulating invasion and metastasis. However, appropriate clinical trials for anti-cancer drugs targeting the invasion of OSCC are incomplete. In this review, we summarize the recent progress on invasion-related factors and emerging molecular determinants which can be used as potential for diagnostic and therapeutic targets in OSCC.

Serum-Soluble E-Cadherin Fragments in Lung Cancer

Aims and background

E-cadherin, also known as uvomorulin or cell-CAM 120/80, is one of the subclasses of cadherins, CA2+-dependent cell adhesion molecules. Several recent studies have suggested that loss of E-cadherin may be associated with tumor progression, such as in lung, gastric, hepatocellular, breast and prostatic carcinoma. Assessment of E-cadherin serum levels in lung cancer showed a relation to histologic type.

Methods and study design

Using an enzyme immunoassay, we determined E-cadherin serum levels in 79 patients affected with lung cancer (stage l–IV), 9 patients with breast cancer, 23 patients with different benign diseases, and 20 healthy patients.

Results

At a specificity level of 90%, E-cadherin diagnostic sensitivity was 66.6%, 47.6% and 43.7% in patients affected with squamous cell carcinoma, small cell carcinoma and adenocarcinoma, respectively.

Conclusions

Preliminary results suggest the use of serum E-cadherin as a prospective tumor marker.

E-cadherin: Its dysregulation in carcinogenesis and clinical implications

E-cadherin is a transmembrane glycoprotein which connects epithelial cells together at adherens junctions. In normal cells, E-cadherin exerts its tumour suppressing role mainly by sequestering β-catenin from its binding to LEF (Lymphoid enhancer factor)/TCF (T cell factor) which serves the function of transcribing genes of the proliferative Wnt signaling pathway. Despite the ongoing debate on whether the loss of E-cadherin is the cause or effect of epithelial-mesenchymal transition (EMT), E-cadherin functional loss has frequently been associated with poor prognosis and survival in patients of various cancers. The dysregulation of E-cadherin expression that leads to carcinogenesis happens mostly at the epigenetic level but there are cases of genetic alterations as well. E-cadherin expression has been linked to the cellular functions of invasiveness reduction, growth inhibition, apoptosis, cell cycle arrest and differentiation. Studies on various cancers have shown that these different cellular functions are also interdependent. Recent studies have reported a rapid expansion of E-cadherin clinical relevance in various cancers. This review article summarises the multifaceted effect E-cadherin expression has on cellular functions in the context of carcinogenesis as well as its clinical implications in diagnosis, prognosis and therapeutics.

Patients with advanced oral squamous cell carcinoma have high levels of soluble E-cadherin in the saliva

BACKGROUND

The objective of this study was to assess the potential clinical value of the concentration of soluble salivary E-cadherin (sE-cadherin) compared with the clinical value of the presence of membranous E-cadherin (mE-cadherin) in oral squamous cell carcinoma tumor tissues.

MATERIAL AND METHODS

Data regarding patient demographics, clinical stage, saliva and tumor tissue samples were collected. The saliva was analyzed for sE-cadherin protein levels and was compared to the mE-cadherin immunohistochemical expression levels in tumor tissues, which were assessed via the HercepTest® method. Patients without cancer were included in the study as a control group for comparisons of the sE-cadherin levels.

RESULTS

sE-cadherin levels in the saliva of patients without cancer were lower than those in patients with cancer, and the difference was statistically significant (p=0.031). Low mE-cadherin expression was statistically significantly associated with lymph node positivity (p=0.015) and advanced clinical stage (p=0.001). The inverse relationship between mE-cadherin and sE-cadherin was significant in terms of lymph node positivity (p=0.014) and advanced clinical stage (p=0.037).

CONCLUSIONS

The results suggest that sE-cadherin levels are significantly increased in patients with oral cancer and that its low expression within the membrane as well as the progression of the disease appear to be inversely associated with levels of sE-cadherin in the saliva.

Assessment of Vitronectin, Soluble Epithelial-Cadherin and TGF-β1 as a Serum Biomarker with Predictive Value for Endometrial and Ovarian Cancers

Objectives

Extracellular matrix components, including vitronectin (VN), soluble epithelial-cadherin (sE-cadherin) and transforming growth factor-beta 1 (TGF-β1), play a key role in the invasion and metastasis of cancer. The objective of the study was to determine the clinical significance of serum levels of these molecules in patients with endometrial and ovarian cancers.

Materials and Methods

Serum levels of VN, sE-cadherin and TGF-β1 in patients with endometrial (n=28) and ovarian cancers (n=40) and healthy controls (n=41) were measured by ELISA using commercial kits.

Results

A significant difference was found in VN, sE-cadherin and TGF-β1 levels between patients and healthy controls (p<0.01, p<0.01 and p<0.05, respectively). Serum VN and sE-cadherin levels were decreased significantly in both endometrial and ovarian cancer patients compared to controls (p<0.01, p<0.01, respectively). Conversely, TGF-β1 levels were increased significantly in patients with ovarian cancer as compared to controls (p<0.01). There was no significant difference between healthy controls and endometrial cancer patients.

Conclusion

In conclusion, our study reveals that serum VN, sE-cadherin and TGF-β1 levels can be candidate targets for providing new diagnostic procedures in endometrial and ovarian cancers.

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.

PREDICTIVE CIRCULATING MARKERS FOR ANTHRACYCLINE CHEMOTHERAPY IN NON-METASTATIC BREAST CANCER

Anthracyclines are used in breast cancer both in early and advanced stages and their recommendation together with taxanes, either concurrently or sequentially, is debatable and individualized by phenotype. Circulating biomarkers have already been introduced in clinical practice for metastatic disease monitoring. We questioned whether it might be a role for these markers in neoadjuvant and adjuvant settings too and a general review was conducted. CK18 and CTC were found predictive for anthracycline related response in preoperative setting. Soluble E-cadherin is promising, a retrospective analysis showing a direct correlation with clinical response. CEA, CA 15-3 and HER2 ECD are not of interest for their predictive role.

The extracellular domain of E cadherin linked to invasiveness in colorectal cancer: a new resistance and relapses monitoring serum-bio marker?

PURPOSE

Multiple studies have attempted to demonstrate the interest of the cell adhesion marker, E cadherin, as a diagnostic and prognosis marker in colorectal cancer (CRC). However, it was considered non specific.

MATERIALS AND METHODS

Studies were carried out with CRC cell lines and patients' cohort operated for CRC. The expression of E cadherin was studied after 5 fluorouracil (5FU) treatment and correlated to CRC relapse, chemo-resistance and survival.

RESULTS

In CRC cell lines derived from high tumor stages, extracellular domain of E cadherin expression decreased after 5FU treatment whereas it increased in supernatants. Interestingly, only specific cleaved forms at 55 kDa of E cadherin were detected in supernatants. In CRC surgical patients, more importantly concerning extracellular E cadherin domain, a decreased expression was observed in tissues in function of CRC stages whereas an increased expression was found in sera. Moreover, there is an increasing trend of survival with weak serum E cadherin secretion, reinforcing the implication of this protein in CRC evolution.

DISCUSSION

The extracellular domain can be defined as a 5FU resistance marker and allow CRC monitoring.

Circulating cellular adhesion molecules and risk of diabetes: the Multi-Ethnic Study of Atherosclerosis (MESA)

AIMS

To test the hypothesis that soluble cellular adhesion molecules would be positively and independently associated with risk of diabetes.

METHODS

Soluble levels of six cellular adhesion molecules (ICAM-1, E-selectin, VCAM-1, E-cadherin, L-selectin and P-selectin) were measured in participants in the Multi-Ethnic Study of Atherosclerosis, a prospective cohort study. Participants were then followed for up to 10 years to ascertain incident diabetes.

RESULTS

Sample sizes ranged from 826 to 2185. After adjusting for age, sex, race/ethnicity, BMI and fasting glucose or HbA1c , four cellular adhesion molecules (ICAM-1, E-selectin, VCAM-1 and E-cadherin) were positively associated with incident diabetes and there was a statistically significant trend across quartiles. Comparing the incidence of diabetes in the highest and lowest quartiles of each cellular adhesion molecule, the magnitude of association was largest for E-selectin (hazard ratio 2.49; 95% CI 1.26-4.93) and ICAM-1 (hazard ratio 1.76; 95% CI 1.22-2.55) in fully adjusted models. Tests of effect modification by racial/ethnic group and sex were not statistically significant for any of the cellular adhesion molecules (P > 0.05).

CONCLUSIONS

The finding of significant associations between multiple cellular adhesion molecules and incident diabetes may lend further support to the hypothesis that microvascular endothelial dysfunction contributes to risk of diabetes.

Formation of intracellular lumina in human prostate carcinoma (DU145) cells, maturation into signet cells, and the cribriform morphology of tumors

The intracellular or intracytoplasmic lumen (IL) is an enigmatic histological structure that occurs in various tumor cells. A reassessment of diverse ILs fine-structure micrographs obtained out of previous studies encompassing the human prostate carcinoma (DU145) cell line and xenotransplanted carcinomas enabled us to propose aspects of ILs development in cancer cells: a combination of altered expressions in intercellular contacts and their cytoskeletal components would favor a disarray of self-apical polarity orientation; those defects, associated with a local, entwined enriched membranous structures growing as microvilli-like formations out of a disrupted endoplasm and trans-Golgi sorting, create ILs in cells' perikarya. These misplaced intracytoplasmic domains can become enlarged through spaces made between the finger-like structures by accruing membranes of coalescent intracytoplasmic vesicles then adding microvilli and glycocalyx to constitute ILs. Cationic mucins added with or without a progressive or total loss of microvilli and content generate signet or ring cell, while ILs enlarge. Variable build-ups of these cells' populations in carcinomas result in architectural mix-up of adjacent cells around these voids, misconstrued as new lumen, and establish a "cribriform" tumor pattern that often implies a poor cancer prognosis. Alternatively, cytotoxic changes caused by anticancer pro-oxidant treatment favor membrane alterations and exaggerate the ILs in xenotransplants into intracellular crypts that accompany other tumor degenerative changes.

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.

Genes Regulating Epithelial Polarity Are Critical Suppressors of Esophageal Oncogenesis

Esophageal cancer is an aggressive disease featured by early lymphatic and hematogenous dissemination, and is the sixth leading cause of cancer-related deaths worldwide. The proper formation of apicobasal polarity is essential for normal epithelium physiology and tissue homeostasis, while loss of polarity is a hallmark of cancer development including esophageal oncogenesis. In this review, we summarized the stages of esophageal cancer development associated with the loss or deregulation of epithelial cell apicobasal polarity. Loss of epithelial apicobasal polarity exerts an indispensable role in the initiation of esophageal oncogenesis, tumor progression, and the advancement of tumors from benign to malignant. In particular, we reviewed the involvement of several critical genes, including Lkb1, claudin-4, claudin-7, Par3, Lgl1, E-cadherin, and the Scnn1 gene family. Understanding the role of apicobasal regulators may lead to new paradigms for treatment of esophageal tumors, including improvement of prognostication, early diagnosis, and individually tailored therapeutic interventions in esophageal oncology.

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.

Cleavage of transmembrane junction proteins and their role in regulating epithelial homeostasis

Epithelial tissues form a selective barrier that separates the external environment from the internal tissue milieu. Single epithelial cells are densely packed and associate via distinct intercellular junctions. Intercellular junction proteins not only control barrier properties of the epithelium but also play an important role in regulating epithelial homeostasis that encompasses cell proliferation, migration, differentiation and regulated shedding. Recent studies have revealed that several proteases target epithelial junction proteins during physiological maturation as well as in pathologic states such as inflammation and cancer. This review discusses mechanisms and biological consequences of transmembrane junction protein cleavage. The influence of junction protein cleavage products on pathogenesis of inflammation and cancer is discussed.

Matrix metalloproteinases 2 and 9 and e-cadherin expression in the endometrium during the implantation window of infertile women before in vitro fertilization treatment

OBJECTIVE

To evaluate the expression of endometrial matrix metalloproteinases (MMPs) 2 and 9 and E-cadherin in peri-implantation phase of infertile women who have undergone in vitro fertilization (IVF) cycles.

METHODS

This prospective study included 51 patients who underwent endometrial biopsy during the receptive phase in a menstrual cycle prior to IVF treatment. The samples were evaluated by tissue microarray for immunohistochemical study.

RESULTS

The expression of MMP-2, MMP-9, and E-cadherin in the endometrium prior to IVF treatment was not associated with pregnancy. There was a decrease in E-cadherin immunodetection, the higher the age of the patients, a negative relationship between E-cadherin and MMP-2, and a positive association between MMP-9 and E-cadherin.

CONCLUSIONS

The MMP-2, MMP-9, and E-cadherin are expressed in the endometrium of infertile patients during the receptive phase of the natural menstrual cycle. However, there is no correlation between the expression of these molecules and the clinical IVF outcomes.

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.

Extracellular cleavage of E-cadherin promotes epithelial cell extrusion

Epithelial cell extrusion and subsequent apoptosis is a key mechanism to prevent accumulation of excess cells. Conversely, when driven by oncogene expression, apical cell extrusion is followed by proliferation and represents an initial step of tumorigenesis. E-cadherin (E-cad), the main component of adherens junctions, has been shown to be essential for epithelial cell extrusion, but its mechanistic contribution remains unclear. Here, we provide clear evidence that cell extrusion can be driven by E-cad cleavage, both in a wild type and oncogenic environment. We first show that CDC42 activation in a single epithelial cell results in its efficient MMP-sensitive extrusion through MEK signaling activation and is supported by E-cad cleavage. Second, using an engineered cleavable form of E-cad, we demonstrate that sole extracellular E-cad truncation at the plasma membrane promotes apical extrusion. We propose that extracellular cleavage of E-cad generates a rapid change in cell-cell adhesion sufficient to drive apical cell extrusion. Whereas in normal epithelia, extrusion is followed by apoptosis, when combined to active oncogenic signaling, it is coupled to cell proliferation.

Soluble-E-cadherin activates HER and IAP family members in HER2+ and TNBC human breast cancers

Recent literature suggests that sEcad exerts pro-oncogenic effects, possibly acting as a ligand for the human epidermal growth factor family. Here we show that sEcad is a novel candidate protein for drug targeting since it is increased in human and mouse HER2-positive (HER2+) breast tumors, MMTV-PyMT bodily fluids and human cell culture systems. Mechanistically, we show that endogenous sEcad, and to a lesser extent membrane-bound E-cadherin, associates with HER1, HER2, and HER3 in human and MMTV-PyMT mouse HER2+ tumors and with HER1 in triple negative breast cancer (TNBC) specimens. Furthermore, addition of exogenous recombinant human E-cadherin/Fc chimeric protein (rhEcad/Fc; sEcad) to HER2+ MCF-7, SKBR3, and HER2-negative MDA-MB-231 TNBC cells, resulted in sEcad-HER receptor family interactions, activation of HER1-4 and downstream pro-survival signaling, including the MAPK-PI3K/Akt/mTOR pathways and IAP family members. Lastly, we demonstrate that sEcad exerts pro-oncogenic effects via HER signaling, and acts additively with the HER ligand EGF to promote HER2+ breast cancer proliferation and migration, as well as TNBC invasion. Because sEcad associates and activates many of the oncogenic pathways that tumors utilize for growth and survival and serum levels in patients correlates with clinical response, suggests that targeted therapy against sEcad in combination with other therapies may potentially offer a novel therapeutic strategy for the treatment of breast cancers.

Monoclonal antibody against the ectodomain of E-cadherin (DECMA-1) suppresses breast carcinogenesis: involvement of the HER/PI3K/Akt/mTOR and IAP pathways

PURPOSE

Although targeted therapies against HER2 have been one of the most successful therapeutic strategies for breast cancer, patients eventually developed acquired resistance from compensatory upregulation of alternate HERs and mitogen-activated protein kinase-phosphoinositide 3-kinase (PI3K)/Akt/mTOR signaling. As we and others have shown that the soluble ectodomain fragment of E-cadherin exerts prooncogenic effects via HER1/2-mediated binding and activation of downstream prosurvival pathways, we explored whether targeting this ectodomain [DECMA-1 monoclonal antibody (mAb)] was effective in the treatment of HER2-positive (HER2(+)) breast cancers.

EXPERIMENTAL DESIGN

MMTV-PyMT transgenic mice and HER2(+)/E-cadherin-positive MCF-7 and BT474 trastuzumab-resistant (TtzmR) cells were treated with the DECMA-1 mAb. Antitumor responses were assessed by bromodeoxyuridine incorporation, apoptosis, and necrosis. The underlying intracellular prooncogenic pathways were explored using subcellular fractionation, immunoprecipitation, fluorescence microscopy, and immunoblotting.

RESULTS

Treatment with DECMA-1 mAb significantly delayed tumor onset and attenuated tumor burden in MMTV-PyMT mice by reducing tumor cell proliferation and inducing apoptosis without any detectable cytotoxicity to mice or end-organs. In vitro treatment of MCF-7 and BT474 TtzmR cells reduced proliferation and induced cancer cell apoptosis. Importantly, this inhibition of breast tumorigenesis was due to concomitant downregulation, via ubiquitin-mediated degradation through the lysosome and proteasome pathways, of all HER family members, components of downstream PI3K/Akt/mTOR prosurvival signaling and suppression of inhibitor of apoptosis proteins.

CONCLUSIONS

Our results establish that the E-cadherin ectodomain-specific mAb DECMA-1 inhibits Ecad(+)/HER2(+) breast cancers by hindering tumor growth and inducing apoptosis via downregulation of key oncogenic pathways involved in trastuzumab resistance, thereby establishing a novel therapeutic platform for the treatment of HER2(+) breast cancers.

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.

Lysophosphatidic Acid disrupts junctional integrity and epithelial cohesion in ovarian cancer cells

Ovarian cancer metastasizes via exfoliation of free-floating cells and multicellular aggregates from the primary tumor to the peritoneal cavity. A key event in EOC metastasis is disruption of cell-cell contacts via modulation of intercellular junctional components including cadherins. Ascites is rich in lysophosphatidic acid (LPA), a bioactive lipid that may promote early events in ovarian cancer dissemination. The objective of this paper was to assess the effect of LPA on E-cadherin junctional integrity. We report a loss of junctional E-cadherin in OVCAR3, OVCA429, and OVCA433 cells exposed to LPA. LPA-induced loss of E-cadherin was concentration and time dependent. LPA increased MMP-9 expression and promoted MMP-9-catalyzed E-cadherin ectodomain shedding. Blocking LPA receptor signaling inhibited MMP-9 expression and restored junctional E-cadherin staining. LPA-treated cells demonstrated a significant decrease in epithelial cohesion. Together these data support a model wherein LPA induces MMP-9 expression and MMP-9-catalyzed E-cadherin ectodomain shedding, resulting in loss of E-cadherin junctional integrity and epithelial cohesion, facilitating metastatic dissemination of ovarian cancer cells.

Helicobacter pylori activates calpain via toll-like receptor 2 to disrupt adherens junctions in human gastric epithelial cells

Helicobacter pylori is a risk factor for the development of gastritis, gastroduodenal ulcers, and gastric adenocarcinoma. H. pylori-induced disruption of epithelial adherens junctions (AJs) is thought to promote the development of severe disease; however, the mechanisms whereby H. pylori alters AJ structure remain incompletely understood. The present study demonstrates that H. pylori infection in human patients is associated with elevated serum levels of an 80-kDa E-cadherin ectodomain, whose presence is independent of the presence of serum antibodies against CagA. In vitro, a heat-labile H. pylori surface component activates the host protease calpain in human gastric MKN45 cells independently of the virulence factors CagA and VacA. H. pylori-induced calpain activation results in cleavage of E-cadherin to produce a 100-kDa truncated form and induce relocalization of E-cadherin and β-catenin. Stimulation of MKN45 cells with the toll-like receptor 2 (TLR2) ligand P3C activated calpain and disrupted E-cadherin and β-catenin in a pattern similar to that induced by H. pylori. Inhibition of TLR2 prevented H. pylori-induced calpain activation and AJ disassembly. Together, these findings identify a novel pathway whereby H. pylori activates calpain via TLR2 to disrupt gastric epithelial AJ structure.

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.

Cancer cells cut homophilic cell adhesion molecules and run

The term contact inhibition (CI) encompasses the cellular changes that result in cessation of cell migration and of proliferation due to signals transduced when one cell comes into physical contact with another cell. Cancer cells, however, do not contact inhibit. A molecular understanding of the loss of CI in cancer cells is important for understanding tumor progression. In this Perspective, we propose that the loss of CI observed in cancer cells is the result of extracellular proteolysis of transmembrane cell-cell cell adhesion molecules (CAM) in the tumor microenvironment. Proteolysis of homophilic cell-cell CAMs results in a shed extracellular fragment and released cytoplasmic fragment(s) that disrupts adhesion and induces signals that promote proliferation and/or migration. The importance of this observation in tumor progression is supported by the presence of the shed extracellular fragments of homophilic cell-cell CAMs in serum and tumor tissue of cancer patients suggesting that instead of acting as tumor suppressors, the shed CAM extracellular and cytoplasmic fragments actually function as oncogenes. The study of cell-cell CAM cleavage will provide important and novel means of diagnosing, imaging, and treating tumor progression.

Altered expression of cell adhesion molecules leads to differential uptake of hypericin in urothelial cancer

OBJECTIVE

To elucidate the mechanism behind selective uptake of hypericin in bladder cancer after intravesical instillation for photodynamic diagnosis of urothelial cell carcinoma of bladder.

PATIENTS AND METHODS

Clinical studies were done on a series of 60 bladder cancer biopsies obtained from 28 patients who received intravesical instillations with 8 μM hypericin. Serial 5 μm cryosections were cut from 43 biopsies, and expression of the E-cadherin and associated catenins were determined using immunohistochemical and immunofluorescence staining. Hypericin was assessed using fluorescence confocal laser scanning microscopy. In addition, mRNA expression of these cell-adhesion molecules was analyzed in 17 biopsies using reverse transcription-PCR.

RESULTS

Increased variability in the expression of E-cadherin and associated molecules was found in high-grade, advanced stage bladder carcinoma. An inverse association was found between immunoreactivity for E-cadherin, β- and γ-catenin, and both stage and grade of cancer (P < 0.05). A positive association was observed between the hypericin fluorescence and tumor grade. There was a significant down-regulation of E-cadherin and β-catenin mRNA in grade 2 and 3 tumors. Although a small sample size was studied, it provided sufficient proof to support the hypothesis that altered expression of cell adhesion molecules would lead to preferential hypericin uptake in urothelial cell carcinoma.

CONCLUSIONS

Our study has unraveled one of the many factors contributing to the selective uptake of hypericin in bladder cancer. We have thus identified the effects of alteration of E-cadherin-catenin complex and transformed intercellular junction in the modified paracellular uptake of hypericin that provides the rationale for using this photosensitizer in photodynamic diagnosis of bladder carcinoma.

Soluble E-cadherin: an early marker of severity in acute pancreatitis

BACKGROUND/AIMS

At present, there is no simple test for predicting severity in acute pancreatitis. We investigated the use of an assay of soluble E-cadherin (sE-cadherin).

METHODS

Concentrations of sE-cadherin, from 19 patients with mild acute pancreatitis, 7 patients with severe acute pancreatitis, 11 patients with other acute gastrointestinal pathologies, and 12 healthy subjects were measured using a commercially available sandwich ELISA kit based on two monoclonal antibodies specific to the extracellular fragment of human E-cadherin. Measurements were made at 12 hours or less from onset of pain and also at 24 and 48 hours after onset of pain.

RESULTS

Mean (standard deviation) concentration of sE-cadherin in patients with severe acute pancreatitis at <12 hours was 17780 ng/mL (7853), significantly higher than that of healthy volunteers 5180 ng/mL (1350), P = .0039, patients with other gastrointestinal pathologies 7358 ng/mL (6655), P = .0073, and also significantly higher than that of patients with mild pancreatitis, 7332 ng/mL (2843), P = .0019.

DISCUSSION

Serum sE-cadherin could be an early (within 12 hours) objective marker of severity in acute pancreatitis. This molecule warrants further investigation in the form of a large multicentre trial.

Increased shedding of soluble fragments of P-cadherin in nipple aspirate fluids from women with breast cancer

Breast cancer, a worldwide disease with increasing incidence, develops from ductal/lobular epithelium. Nipple aspirate fluid (NAF), secreted from the breast ducts and lobules, can be analyzed to assess breast metabolic activity. P-cadherin is frequently over-expressed in high-grade invasive breast carcinomas and has been reported to be an enhancer of migration and invasion of breast cancer cells, being correlated with tumor aggressiveness. The present study analyzed the soluble fragment of P-cadherin in milk, NAF and matched plasma samples of healthy subjects and in women with precancer conditions and breast cancer. Soluble P-cadherin was detected in all plasma and milk samples, and in about 31.3% of NAF samples. The lowest levels of soluble P-cadherin were found in plasma, with no significant difference among NoCancer, PreCancer and Cancer patients. The highest concentration of soluble P-cadherin was detected in milk collected during the first trimester of lactation, significantly with respect to all NAF samples. There were significantly higher levels of soluble P-cadherin in NAF from Cancer patients than those in women with NoCancer and PreCancer (P < 0.0001). Although no significant difference was found between in situ and invasive breast cancer, soluble P-cadherin levels were found at high concentrations in c-erbB-2-positive tumors, showing a positive correlation with disease stage grouping and tumor grade, and an inverse relationship with estrogen/progesterone receptor status. High levels of the soluble fragment of P-cadherin in Cancer NAF suggest its possible release via proteolytic processing, favoring cancer cell detachment from breast duct, and suggesting that measuring soluble P-cadherin in NAF may improve the identification of women with increased breast cancer risk.

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.

Nuclear E-cadherin and VHL immunoreactivity are prognostic indicators of clear-cell renal cell carcinoma

The loss of functional von Hippel-Lindau (VHL) tumor suppressor gene is associated with the development of clear-cell renal cell carcinoma (CC-RCC). Recently, VHL was shown to promote the transcription of E-cadherin, an adhesion molecule whose expression is inversely correlated with the aggressive phenotype of numerous epithelial cancers. Here, we performed immunohistochemistry on CC-RCC tissue microarrays to determine the prognostic value of E-cadherin and VHL with respect to Fuhrman grade and clinical prognosis. Low Fuhrman grade and good prognosis associated with positive VHL and E-cadherin immunoreactivity, whereas poor prognosis and high-grade tumors associated with a lack of E-cadherin and lower frequency of VHL staining. A significant portion of CC-RCC with positive VHL immunostaining correlated with nuclear localization of C-terminally cleaved E-cadherin. DNA sequencing revealed in a majority of nuclear E-cadherin-positive CC-RCC, subtle point mutations, deletions and insertions in VHL. Furthermore, nuclear E-cadherin was not observed in chromophobe or papillary RCC, as well as matched normal kidney tissue. In addition, nuclear E-cadherin localization was recapitulated in CC-RCC xenografts devoid of functional VHL or reconstituted with synthetic mutant VHL grown in SCID mice. These findings provide the first evidence of aberrant nuclear localization of E-cadherin in CC-RCC harboring VHL mutations, and suggest potential prognostic value of VHL and E-cadherin in CC-RCC.

Role of E-cadherin in the induction of apoptosis of HPV16-positive CaSki cervical cancer cells during multicellular tumor spheroid formation

Multicellular tumor spheroids (MCTS) are three dimensional cell culture systems induced by suspension culture. MCTS are widely used in cancer research because of their similarity to solid tumors. CaSki cells are derived from a metastatic cervical cancer containing human papillomavirus 16 (HPV16). Cell death of CaSki cells in MCTS has been previously reported, and our model is used to better characterize the mechanisms of cell death of HPV16-positive keratinocytes. In this study, we found that apoptosis of CaSki cells was induced by suspension culture along with the formation of MCTS after 24 h of incubation. In suspended CaSki cells, monoclonal antibodies blocking E-cadherin function inhibited MCTS formation and suppressed suspension-induced apoptosis in a dose-dependent manner. Western blot for E-cadherin detected upregulation of the authentic 120 kDa band from MCTS of CaSki cells as well as a shorter 100 kDa band. Addition of EGF, whose receptor is known to form a complex with E-cadherin, abrogated apoptosis of suspended CaSki cells in a dose-dependent manner. These findings suggest that E-cadherin-dependent cell-cell contact, directly or indirectly, mediates the signal to undergo apoptosis of CaSki cells during MCTS formation, and thus provides new information on the role of E-cadherin in cervical cancer cell apoptosis.

Posttranslational truncation of E-cadherin and significance for tumour progression

Stable intraepithelial adhesion complexes are essential for the maintenance of epithelial integrity. Alterations in these complexes are key events in the development and progression of many diseases. One of the major proteins involved in maintaining epithelial cell-cell adhesion is the cell-adhesion junction protein E-cadherin, a member of the cadherin family of transmembrane adhesion proteins. E-cadherin is involved in many cellular processes including morphogenesis, adhesion, recognition, communication and oncogenesis. Inactivation of its adhesive properties is often a key step in tumour progression and metastasis, leading to its recent description as a tumour suppressor gene. Mutations of the E-cadherin gene CDH1 in gastric and mammary cancers have been well documented and reports of transcriptional repression during tumour progression are increasing. This review examines the role of posttranslational truncation of E-cadherin in cancer cells focusing on implications for tumour progression. The various proteins involved in the directed cleavage of E-cadherin and consequences of these truncations are discussed.