Soluble E-cadherin participates in BLM-induced pulmonary fibrosis by promoting EMT and lung fibroblast migration

Soluble E-cadherin (sE-cad) is an 80 kDa fragment derived from E-cadherin that is shed from the cell surface through proteolytic cleavage and is a biomarker in various cancers that promotes invasion and migration. Alveolar epithelial destruction, aberrant lung fibroblast migration and inflammation contribute to pulmonary fibrosis. Here, we hypothesized that E-cadherin plays an important role in lung fibrosis. In this study, we found that E-cadherin was markedly increased in the bronchoalveolar lavage fluid (BALF) and serum of mice with pulmonary fibrosis and that blocking sE-cad with HECD-1, a neutralizing antibody targeting the ectodomain of E-cadherin, effectively inhibited myofibroblast accumulation and collagen deposition in the lungs after bleomycin (BLM) exposure. Moreover, transforming growth factor-β (TGF-β1) induced the shedding of sE-cad from A549 cells, and treatment with HECD-1 inhibited epithelial-mesenchymal transition (EMT) stimulated by TGF-β1. Fc-E-cadherin (Fc-Ecad), which is an exogenous form of sE-cad, robustly promoted lung fibroblast migration. E-cadherin participates in bleomycin (BLM)-induced lung fibrosis by promoting EMT in the alveolar epithelium and fibroblast activation. E-cadherin may be a novel therapeutic target for lung fibrosis.

Regulation of Soluble E-Cadherin Signaling in Non-Small-Cell Lung Cancer Cells by Nicotine, BDNF, and β-Adrenergic Receptor Ligands

The ectodomain of the transmembrane protein E-cadherin can be cleaved and released in a soluble form referred to as soluble E-cadherin, or sE-cad, accounting for decreased E-cadherin levels at the cell surface. Among the proteases implicated in this cleavage are matrix metalloproteases (MMP), including MMP9. Opposite functions have been reported for full-length E-cadherin and sE-cad. In this study, we found increased MMP9 levels in the media of two non-small cell lung cancer (NSCLC) cell lines, A549 and H1299, treated with BDNF, nicotine, or epinephrine that were decreased upon cell treatment with the β-adrenergic receptor blocker propranolol. Increased MMP9 levels correlated with increased sE-cad levels in A549 cell media, and knockdown of MMP9 in A549 cells led to downregulation of sE-cad levels in the media. Previously, we reported that A549 and H1299 cell viability increased with nicotine and/or BDNF treatment and decreased upon treatment with propranolol. In investigating the function of sE-cad, we found that immunodepletion of sE-cad from the media of A549 cells untreated or treated with BDNF, nicotine, or epinephrine reduced activation of EGFR and IGF-1R, decreased PI3K and ERK1/2 activities, increased p53 activation, decreased cell viability, and increased apoptosis, while no effects were found using H1299 cells under all conditions tested.

Soluble E-cadherin promotes invasiveness of neoplastic cells in salivary gland carcinoma ex pleomorphic adenoma

BACKGROUND

Soluble E-cadherin (sEcad), a tumor suppressor gene, has pro-oncogenic effects by binding to human epithelial growth factor receptor 2 (HER-2). In our previous study, 1/3 of carcinoma ex pleomorphic adenoma (CXPA) cases had HER-2 amplification, which is associated with tumorigenesis and malignancy. This study examines the role of sEcad in HER-2 amplified CXPA.

METHODS

Immunohistochemistry was used to examine E-cadherin (Ecad) expression in HER-2-amplified CXPA samples (n = 35). Western blot and ELISA were used to detect sEcad in two samples with Ecad and HER-2 overexpression and CXPA cell line. Lentivirus-mediated transfection was performed to knock down sEcad in CXPA cells. The cell proliferation, wound healing, and transwell assays were used to compare sEcad-knockdown cells with cells pretreated with recombinant human sEcad (rhEcad/Fc). sEcad and HER-2 interaction was determined through co-immunoprecipitation. RNA-sequencing, differential expression analysis, GO and KEGG analysis were used to identify sEcad-related signaling pathways and their protein phosphorylation levels were verified by western blotting.

RESULTS

Ecad was overexpressed in 77.1% of HER-2-positive CXPA, and sEcad was found in the CXPA cell line and two samples. sEcad promoted CXPA migration and invasion in vitro without sEcad and HER-2 interaction. sEcad-related differentially expressed genes were enriched in the IL-17, cAMP, and MAPK signaling pathways. Furthermore, sEcad activated the phosphorylation of Akt and MAPK/ERK signaling pathways.

CONCLUSIONS

Most HER-2⁺ CXPAs express Ecad. sEcad could affect the invasiveness and migration of in vitro CXPA cells without HER-2. sEcad may be a therapeutic biomarker for CXPA patients.

Potential value of circulatory microRNA10b gene expression and its target E-cadherin as a prognostic and metastatic prediction marker for breast cancer

Background

Breast cancer (BC) is the leading cause of cancer death in women worldwide. Most BC studies on candidate microRNAs were tissue specimen based. Recently, there has been a focus on the study of cell‐free circulating miRNAs as promising biomarkers in (BC) diagnosis and prognosis. Therefore, we aimed to investigate the circulating levels of miR‐10b and its target soluble E‐ cadherin as potentially easily accessible biomarkers for breast cancer.

Methods

Sixty‐one breast cancer patients and forty‐eight age‐ and sex‐matched healthy volunteers serving as a control group were enrolled in the present study. Serum samples were used to assess miRNA10b expression by TaqMan miRNA assay technique. In addition, soluble E‐cadherin expression level in serum was determined using ELISA technique.

Result

Circulating miR‐10b expression level and serum sE‐cadherin was significantly upregulated in patients with BC compared to controls. Moreover, serum miR‐10b displayed progressive up‐regulation in advanced stages with higher level in metastatic compared to non‐metastatic BC. Additionally, the combined use of both serum miR‐10b and sE‐cadherin revealed the highest sensitivity and specificity for detection of BC metastasis (92.9% and 97.9% respectively) with an area under curve (AUC) of 0.98, 95% CI (0.958–1.00).

Conclusion

Our data suggest that circulating miR‐10b could be utilized as a potential non‐invasive serum biomarker for diagnosis and prognosis of breast cancer with better performance to predict BC metastasis achieved on measuring it simultaneously with serum sE‐cadherin. Further studies with a large cohort of patients are warranted to validate the serum biomarker for breast cancer management.

Clusterin and Its Potential Regulatory microRNAs as a Part of Secretome for the Diagnosis of Abnormally Invasive Placenta: Accreta, Increta, and Percreta Cases

Magnetic resonance imaging (MRI) and ultrasound methods used for the diagnosis of an abnormally invasive placenta (AIP) have a wide range of sensitivity (Se, 33–93%) and specificity (Sp, 71–100%) levels, which results in a high risk of unfavorable maternal and perinatal outcomes. The relevance of optimizing the diagnosis of AIP is beyond doubt. Given the epigenetic nature of trophoblast invasion, we aimed to quantitate microRNAs and proteins of their target genes that are potentially associated with AIP in blood plasma samples from 64 pregnant women at gestation weeks 30–34 by reverse transcription coupled with polymerase chain reaction (RT-PCR) and Western blotting, respectively. Statistically significant increases in the expression levels of hsa-miR-17-5p, hsa-miR-21-5p, hsa-miR-25-3p, hsa-miR-92a-3p, and hsa-miR-320a-3p were revealed in the groups of women with AIP (accreta, increta, percreta) relative to the group of women with scars on the uterus or to the group with placenta previa. Opposite changes in the expression level of “gene–target protein/miRNA” pairs were found for the α-subunit of the clusterin secretory form and any of the hsa-miR-21-5p, hsa-miR-25-3p, hsa-miR-92a-3p, hsa-miR-320a-3p, and hsa-miR-17-5p in all cases of AIP. The developed logistic regression models to diagnose AIP cases of various severity gave Se values of 88.8–100% and Sp values of 91.6–100% using a combination of hsa-miR-21-5p, hsa-miR-92a-3p, hsa-miR-320a-3p, or clusterin levels.

High Concentrations of Serum Soluble E-Cadherin in Patients With Q Fever

Cadherins switching is a hallmark of neoplasic processes. The E-cadherin (E-cad) subtype is one of the surface molecules regulating cell-to-cell adhesion. After its cleavage by sheddases, a soluble fragment (sE-cad) is released that has been identified as a pro-carcinogenic inflammatory signal in several bacteria-induced cancers. Recently we reported that Q fever, a disease due to Coxiella burnetii infection, can be complicated by occurrence of non-Hodgkin lymphoma (NHL). Therefore, we studied E-cad switching in Q fever. The sE-cad levels were found increased in the sera of acute and persistent Q fever patients, whereas they remained at the baseline in controls groups of healthy donors, people cured of Q fever, patients suffering from unrelated inflammatory diseases, and past Q fever patients who developed NHL. These results indicate that sE-cad can be considered as a new biomarker of C. burnetii infection rather than a marker of NHL-associated to Q fever. We wondered if changes in sE-cad reflected variations in the CDH1 gene transcription. The expression of E-cad mRNA and its intracellular ligand β-catenin was down-regulated in peripheral blood mononuclear cells (PBMCs) of patients with either acute or persistent forms of Q fever. Indeed, a lower cell-surface expression of E-cad was measured in a minority (<5%) subpopulation of HLADR⁺/CD16⁺ monocytes from patients with acute Q fever. However, a very strong increase in E-cad expression was observed on more than 30% of the HLADR⁺/CD16⁺ monocytes of persistent Q fever patients, a cell subpopulation known to be a target for C. burnetii in humans. An experimental in vitro infection of healthy donors' PBMCs with C. burnetii, was performed to directly evaluate the link between C. burnetii interaction with PBMCs and their E-cad expression. A significant increase in the percentage of HLADR⁺/CD16⁺ monocytes expressing E-cad was measured after PBMCs had been incubated for 8 h with C. burnetii Nine Mile strain. Altogether, these data demonstrate that C. burnetii severely impairs the E-cad expression in circulating cells of Q fever patients.

New insights into the role of soluble E-cadherin in tumor angiogenesis

A key to successful metastasis is the formation of new vasculature, known as angiogenesis. Therefore, it is of great interest to unravel the underlying molecular mechanisms of tumor angiogenesis. Cadherins are a major class of cell surface receptors. The loss of cadherins, especially E-cadherin, is a well-established marker for tumor metastasis. Loss of E-cadherin is also a defining characteristic of several carcinomas, such as lobular carcinoma of the breast, and de-differentiated endometrioid carcinoma of the endometrium and ovary, which are known to be associated with more aggressive tumor behavior. Although E-cadherin is synthesized as a transmembrane molecule, its extracellular domain can be enzymatically cleaved off and released as a soluble E-cadherin (sE-cad), and this accounts for the loss of E-cadherin function or expression that has been implicated in tumor progression and metastasis. Importantly, sE-cad is present at high levels in the serum and malignant ascites of ovarian carcinoma patients. Nevertheless, little is known about how this essential protein dictates metastasis. Hitherto, many studies have given attention only to the dominant negative role of the loss of E-cadherin in weakening cell-cell adhesion, however, it is not known if sE-cad has biological activity in itself. In addition, the release mechanism of sE-cad has remained elusive. Here we show for the first time that sE-cad is a pivotal regulator of angiogenesis. We further show that exosomes are a novel major platform for the cleavage and release of sE-cad in vitro, in vivo and in patients’ derived samples (Nat Commun, 9: 2270).

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.

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.