Investigation of intercellular adhesion molecules (ICAMs) gene expressions in patients with Barrett's esophagus

Toll-like Receptor 4 Mediates Reflux-Induced Inflammation in a Murine Reflux Model

Dysregulation of toll-like receptor (TLR) signaling within the gastrointestinal epithelium has been associated with uncontrolled inflammation and tumorigenesis. We sought to evaluate the role of TLR4 in the development of gastroesophageal reflux-mediated inflammation and mucosal changes of the distal esophagus. Verified human esophageal Barrett's cells with high grade dysplasia (CPB) and esophageal adenocarcinoma cells (OE33) were treated with deoxycholic acid for 24 hours. Cells were pretreated with a TLR4-specific inhibitor peptide 2 hours prior to deoxycholic acid treatment. Inflammatory markers were evaluated using immunoblotting and enzyme-linked immunosorbent assay. A surgical reflux mouse model was generated by performing a side-to-side anastomosis between the second portion of the duodenum and the gastroesophageal junction. Control animals underwent laparotomy with incision and closure of the esophagus superior to the gastroesophageal junction (sham procedure). Esophageal sections were evaluated using hematoxylin and eosin staining and immunohistochemistry. Deoxycholic acid increased expression of inflammatory markers including intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and interleukin 8. Pretreatment with a TLR4 inhibitor significantly decreased deoxycholic acid-induced inflammatory marker expression. C3H/HeNCrl mice demonstrated a significant increase in mucosal hyperplasia and proliferation following DGEA compared to sham procedure. TLR4 mutant mice (C3H/HeJ) undergoing DGEA demonstrated an attenuated hyperplastic and proliferative response compared to C3H/HeNCrl mice. Inhibition of TLR4 signaling attenuates reflux-induced inflammation in vivo. These findings identify TLR4 inhibition as a potential therapeutic target to halt the progression of pathologic esophageal changes developing in the setting of chronic gastroesophageal reflux disease.

Expression of Adhesion Molecules in a Gastroduodenal Reflux Murine Model

BACKGROUND

Various adhesion molecules including intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) have been shown to play a role in inflammation as well as contribute to tumor progression and prognosis. We hypothesized that gastroduodenal reflux upregulates ICAM-1 and VCAM-1 expression in the distal esophagus, serving as possible early markers of pathologic esophageal disease.

METHODS

Normal human esophageal epithelial cells (HET1A), Barrett's cells (CPB), and esophageal adenocarcinoma cells (FLO1 and OE33) were treated with deoxycholic acid (DCA) at increasing concentrations for 24 hours. Adhesion molecule expression was assessed using immunoblotting. A surgical mouse reflux model was generated by performing a side-to-side anastomosis between the gastroesophageal junction and the first portion of the duodenum (duodeno-gastroesophageal anastomosis, DGEA). Esophageal sections were evaluated using H&E staining, immunohistochemistry, and immunofluorescence.

RESULTS

DCA induced a significant increase in ICAM-1 and VCAM-1 expression in HET1A, CPB, FLO1, and OE33 cells. Animals undergoing DGEA demonstrated a significant increase in mucosal hyperplasia (p<0.0001) and cellular proliferation (p<0.0001) compared to control animals. Immunofluorescence and western blot analysis of the lower esophagus demonstrated significant upregulation of ICAM-1 (p=0.005), with no change in VCAM-1 expression (p=0.82).

CONCLUSIONS

Our results reveal that ICAM-1 and VCAM-1 are upregulated in response to in vitro reflux treatment of normal esophageal epithelial cells. However, upon investigation using a mouse reflux model, ICAM-1 is noticeably upregulated without a concomitant increase in VCAM-1. These findings identify ICAM-1, but not VCAM-1, as a potential player in early esophageal disease developing from chronic reflux exposure.

Secretory Phospholipase A2 Inhibition Attenuates Adhesive Properties of Esophageal Barrett's Cells

BACKGROUND

Gastroesophageal reflux and Barrett's esophagus are significant risk factors for the development of esophageal adenocarcinoma. Group IIa secretory phospholipase A₂ (sPLA₂) catalyzes the production of various proinflammatory metabolites and plays a critical role in promoting reflux-induced inflammatory changes within the distal esophagus. We hypothesized that inhibition of sPLA₂ in human Barrett's cells would attenuate adhesion molecule expression via decreased activation of nuclear factor kappa B (NF-κB) and decrease cell proliferation, possibly mitigating the invasive potential of Barrett's esophagus.

MATERIALS AND METHODS

Normal human esophageal epithelial cells (HET1A) and Barrett's cells (CPB) were assayed for baseline sPLA₂ expression. CPB cells were treated with a specific inhibitor of sPLA₂ followed by tumor necrosis factor-α. Protein expression was evaluated using immunoblotting. Cell proliferation was assessed using an MTS cell proliferation assay kit. Statistical analysis was performed using the Student's t-test or analysis of variance, where appropriate.

RESULTS

CPB cells demonstrated higher baseline sPLA₂ expression than HET1A cells (P = 0.0005). Treatment with 30 μM sPLA₂ inhibitor significantly attenuated intercellular adhesion molecule-1 (P = 0.004) and vascular cell adhesion molecule-1 (P < 0.0001) expression as well as decreased NF-κB activation (P = 0.002). sPLA₂ inhibition decreased cell proliferation in a dose-dependent manner (P < 0.001 for 15, 20, and 30 μM doses).

CONCLUSIONS

sPLA₂ inhibition in human Barrett's cells decreases cellular adhesive properties and NF-κB activation as well as decreases cell proliferation, signifying downregulation of the inflammatory response and possible attenuation of cellular malignant potential. These findings identify sPLA₂ inhibition as a potential chemopreventive target for premalignant lesions of the esophagus.

An adhesion based approach for the detection of esophageal cancer

Esophageal cancer has a 5 year survival rate of ∼20%. This dismal prognosis is due, in part, to the fact that esophageal cancer often presents at a late stage. Thus, there is a critical need for assays that enable the early detection of cancerous tissue within the esophagus. The luminal surface of the esophagus expresses signature molecule(s) at sites of transformation providing an avenue for the development of in situ assays that detect neoplastic growth within the esophagus. An attractive approach, receiving increased attention, is the endoscopic administration of particles conjugated with ligands to signature molecules present on transforming tissue. Detection of the particles within the esophagus, post-washing, would indicate the presence of the signature molecule and thus transforming tissue. In this work, we utilized cancerous and normal esophageal cells to provide in vitro proof of principle for this approach utilizing ligand-conjugated microspheres and demonstrate the need, and provide the framework for, engineering this technology. Specifically, the study (i) reveals selective increased expression of signature molecules on cancerous esophageal cells relative to normal cells; (ii) demonstrates selective binding of ligand-conjugated microspheres to cancerous esophageal cells relative to normal cells; (iii) demonstrates that the selective recognition of cancerous, relative to normal esophageal cells, is highly dependent on the biophysical design of the assay; and (iv) advocates utilizing the knowledge from the field of cell adhesion as a guide for the effective development of ligand-conjugated particle-based schemes that seek to detect esophageal oncogenesis in situ.

Identification of key pathways and genes in Barrett's esophagus using integrated bioinformatics methods

Barrett's esophagus (BE) is a premalignant lesion of esophageal adenocarcinoma. The aim of the present study was to investigate the possible mechanisms and biomarkers of BE. To identify the differentially expressed microRNAs (DEmiRNAs) and genes (DEGs) in BE, the miRNA expression profile GSE20099 and the gene expression profiles GSE26886, GSE13083 and GSE34619 were obtained from the Gene Expression Omnibus (GEO) database. DEGs and DEmiRNAs were screened for using the GEO2R tool. Using DAVID, functional and pathway enrichment analysis was performed to explore the biological function of identified DEGs. The protein-protein interaction (PPI) network was detected using STRING and constructed by Cytoscape software. Furthermore, targets of identified DEmiRNAs were predicted by the miRecords database, then integrated with the identified DEGs to obtain key genes involved in BE. In total, 311 DEGs were identified. These genes were significantly enriched in the pancreatic secretion, metabolic pathways and cytochrome P450 drug metabolism pathways. In the PPI network, 16 hub genes, including keratin 16, cystic fibrosis transmembrane conductance regulator, involucrin, protein kinase C α and cadherin 17 were identified. Following integration of the predicted target genes of DEmiRNAs with DEGs, three key BE genes were identified: PRKCA, CDH17 and epiregulin. In conclusion, a comprehensive bioinformatics analysis of identified DEGs and DEmiRNAs was performed to elucidate potential pathways and biomarkers involved in the development of BE.

Association Between Intercellular Adhesion Molecule-1, -2, -3 Plasma Levels and Disease Activity of Ankylosing Spondylitis in the Chinese Han Population

STUDY DESIGN

We investigated the association between ICAM-1, -2, -3 plasma levels and ankylosing spondylitis (AS) disease activity.

OBJECTIVE

In the present study, we aimed to investigate the association between ICAM-1, -2, -3 plasma levels and AS disease activity in the Chinese Han population.

SUMMARY OF BACKGROUND DATA

AS is a chronic inflammatory rheumatic disease that effects the sacroiliac joints and axial skeleton. The intercellular adhesion molecules (ICAMs) are members of the immunoglobulin superfamily and have been identified to play major roles in inflammation and immune responses.

METHODS

A total of 60 patients with AS and 60 healthy individuals were selected. The plasma levels of proinflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and ICAM-1, -2, -3, were analyzed by ELISA. Disease severity-related indexes, including the Bath ankylosing spondylitis disease activity index (BASDAI), Bath ankylosing spondylitis functional index (BASFI), and ankylosing spondylitis disease activity score (ASDAS), were assessed, along with the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level.

RESULTS

Both ICAM-1 and ICAM-2 levels in plasma were markedly increased in AS patients compared with levels in the plasma of controls. There was no difference between controls and patients in term of ICAM-3 levels. Furthermore, in patients, correlation analysis showed that TNF-α and IL-6 production, as well as the ESR and CRP levels, have positive relationships with ICAM-1 and ICAM-2 plasma levels; the BASDAI, BASFI, and ASDAS scores were also found to be positively correlated with ICAM-2. However, no significant correlations between ICAM-1 levels and BASDAI, BASFI, or ASDAS were detected in our study.

CONCLUSION

The current findings suggest that ICAM-2 may be a potential biomarker reflecting disease activity and functional ability in AS patients.

LEVEL OF EVIDENCE

5.

Downregulation of human intercellular adhesion molecule-1 attenuates the metastatic ability in human breast cancer cell lines

Intercellular adhesion molecule-1 (ICAM-1) is a cell surface glycoprotein that belongs to immunoglobulin superfamily and plays an important role in tumor cell expansion or metastasis. However, the detailed mechanisms of ICAM-1 in breast cancer remain unclear. In this study, we evaluated the expression level of ICAM-1 in breast cancer using tissue microarray and clinical tissue specimens by immunohistochemical method, and the results revealed that ICAM-1 is highly expressed in the breast cancer tissues. To investigate whether ICAM-1 can affect the metastasis ability in breast cancer, we knocked down ICAM-1 expression in breast cancer cell line MCF-7 by using lentivirus-mediated RNA interference (RNAi). As a result, we stably silenced ICAM-1 expression in MCF-7 cells by infection with lentivirus expressing green fluorescent protein (GFP), the change of metastatic ability of MCF-7 cells was assessed by wound-healing assay, Transwell assay or clone formation assay. Our results showed that silencing of ICAM-1 can inhibit the metastatic ability of MCF-7 cell lines in vitro significantly, and the decreased migration and invasion was accompanied by a reduction of MMP-14. These results implying that ICAM-1 might be involved in the progression of breast cancer metastasis and lentivirus-mediated silencing of ICAM-1 might be a potential therapeutic approach for the treatment of breast cancer.