Beth Bednarchik

The MicroRNAs, MiR-31 and MiR-375, as Candidate Markers in Barrett's Esophageal Carcinogenesis

There is a critical need to identify molecular markers that can reliably aid in stratifying esophageal adenocarcinoma (EAC) risk in patients with Barretts esophagus. MicroRNAs (miRNA/miR) are one such class of biomolecules. In the present cross‐sectional study, we characterized miRNA alterations in progressive stages of neoplastic development, i.e., metaplasia–dysplasia–adenocarcinoma, with an aim to identify candidate miRNAs potentially associated with progression. Using next generation sequencing (NGS) as an agnostic discovery platform, followed by quantitative real‐time PCR (qPCR) validation in a total of 20 EACs, we identified 26 miRNAs that are highly and frequently deregulated in EACs (≥4‐fold in >50% of cases) when compared to paired normal esophageal squamous (nSQ) tissue. We then assessed the 26 EAC‐derived miRNAs in laser microdissected biopsy pairs of Barretts metaplasia (BM)/nSQ (n = 15), and high‐grade dysplasia (HGD)/nSQ (n = 14) by qPCR, to map the timing of deregulation during progression from BM to HGD and to EAC. We found that 23 of the 26 candidate miRNAs were deregulated at the earliest step, BM, and therefore noninformative as molecular markers of progression. Two miRNAs, miR‐31 and −31*, however, showed frequent downregulation only in HGD and EAC cases suggesting association with transition from BM to HGD. A third miRNA, miR‐375, showed marked downregulation exclusively in EACs and in none of the BM or HGD lesions, suggesting its association with progression to invasive carcinoma. Taken together, we propose miR‐31 and −375 as novel candidate microRNAs specifically associated with early‐ and late‐stage malignant progression, respectively, in Barretts esophagus.

Association of insulin and insulin-like growth factors with Barrett's oesophagus

Background It is postulated that high serum levels of insulin and insulin growth factor 1 (IGF-1) mediate obesity-associated carcinogenesis. The relationship of insulin, IGF-1 and IGF binding proteins (IGFBP) with Barretts oesophagus (BO) has not been well examined. Methods Serum levels of insulin and IGFBPs in patients with BO were compared with two separate control groups: subjects with gastro-oesophageal reflux disease (GORD) and screening colonoscopy controls. Fasting insulin, IGF-1 and IGFBPs were assayed in the serum of BO cases (n=135), GORD (n=135) and screening colonoscopy (n=932) controls recruited prospectively at two academic hospitals. Logistic regression was used to estimate the risk of BO. Results Patients in the highest tertile of serum insulin levels had an increased risk of BO compared with colonoscopy controls (adjusted OR 2.02, 95% CI 1.15 to 3.54) but not compared with GORD controls (adjusted OR 1.55, 95% CI 0.76 to 3.15). Serum IGF-1 levels in the highest tertile were associated with an increased risk of BO (adjusted OR 4.05, 95% CI 2.01 to 8.17) compared with the screening colonoscopy control group but were not significantly different from the GORD control group (adjusted OR 0.57, 95% CI 0.27 to 1.17). IGFBP-1 levels in the highest tertile were inversely associated with a risk of BO in comparison with the screening colonoscopy controls (adjusted OR 0.11, 95% CI 0.05 to 0.24) but were not significantly different from the GORD control group (adjusted OR 1.04, 95% CI 0.49 to 2.16). IGFBP-3 levels in the highest tertile were inversely associated with the risk of BO compared with the GORD controls (OR 0.36, 95% CI 0.16 to 0.81) and also when compared with the colonoscopy controls (OR 0.40, 95% CI 0.20 to 0.79). Conclusions These results provide support for the hypothesis that the insulin/IGF signalling pathways have a role in the development of BO.

Human β-Defensin 3 Peptide Is Increased and Redistributed in Crohn’s Ileitis

Background:Antimicrobial peptides (AMPs) maintain a sterile environment in intestinal crypts, limiting microbial colonization and invasion. Decreased AMP expression is proposed to increase the risk for inflammatory bowel disease. Expression and function of inducible AMPs, human &bgr;-defensin 2 and 3 (hBD-2 and hBD-3), remain poorly characterized in healthy and chronically inflamed intestine. Methods:Peptide concentrations of hBD-2 and hBD-3 in serum and intestinal biopsies of subjects with ulcerative colitis and Crohn’s disease (CD), and those of healthy subjects were measured by ELISA. Messenger RNA of hBD-2 and hBD-3 was quantified by quantitative PCR in biopsies from the terminal ileum (TI) of patients with CD and healthy controls. Peptide localization of hBD-3 in the TI was visualized by confocal microscopy. Results:Immunoreactive hBD-3 peptide is present in the TI and colon in healthy subjects. In the TI of patients with CD, hBD-3, but not hBD-2 peptide, is increased 4-fold, whereas hBD-2 peptide is elevated in the serum. Messenger RNA of hBD-3 in the CD TI remains unchanged and does not correlate with hBD-3 peptide expression. However, hBD-3 is localized to Paneth cell granules and the apical surface of the healthy columnar epithelium. In CD, hBD-3 peptide location switches to the basolateral surface of the columnar epithelium and is diffusely distributed within the lamina propria. Conclusion:The peptide hBD-3 throughout the healthy gastrointestinal tract suggests a role in maintaining balance between host defenses and commensal microbiota. Increased and relocalized secretion of hBD-3 toward the lamina propria in the CD TI indicates possible local immunomodulation during chronic inflammation, whereas increased serum hBD-2 in CD implicates its systemic antimicrobial and immunomodulatory role.

Associations of Serum Adiponectin and Leptin With Barrett’s Esophagus

BACKGROUND & AIMS Central adiposity is a risk factor for Barretts esophagus (BE). Serum levels of adiponectin and leptin are deregulated in obese states and are implicated as putative mediators in the pathophysiology of esophageal columnar metaplasia. We describe associations between serum adiponectin and leptin levels with BE. METHODS Patients were recruited prospectively for a case-control study. Fasting serum levels of adiponectin and leptin were measured in 135 patients with BE and compared with 2 separate control groups: 133 subjects with gastroesophageal reflux disease (GERD) and 1157 colon screening controls. RESULTS Multivariate analyses adjusted for age, race, and waist-to-hip ratio showed that patients within the highest tertile of serum adiponectin level had decreased odds of BE compared with screening colonoscopy controls (odds ratio [OR], 0.42; 95% confidence interval [CI], 0.22-0.80). This effect was more pronounced in men (OR, 0.35; 95% CI, 0.17-0.74) compared with women (OR, 0.71; 95% CI, 0.17-3.03). In comparisons of BE cases with GERD controls, subjects within the highest tertile of serum adiponectin level showed decreased odds of BE (OR, 0.65; 95% CI, 0.31-1.36), however, this was not statistically significant. Patients in the highest tertile of serum leptin level did not have a significantly increased risk of BE in comparison with GERD (OR, 1.32; 95% CI, 0.61-2.88) or screening colonoscopy controls (OR, 1.57; 95% CI, 0.82-3.04) in analyses including both sexes. Based on sex-specific analyses, sex did not significantly alter the association of leptin with odds of BE. CONCLUSIONS Serum adiponectin was associated inversely with BE and this effect was more pronounced in men, whereas serum leptin showed no evidence of association with BE in comparisons with multiple control groups. The exact mechanism, if any, by which these adipokines promote metaplasia in the esophagus needs to be explored further.

Insulin/Insulin-Like Growth Factor-1 Pathway in Barrett's Carcinogenesis.

OBJECTIVES:Obesity-associated carcinogenesis is postulated to be mediated through the proliferative actions of insulin and the insulin-like growth factor (IGF) family. The aim of this study was to determine whether the insulin/IGF-1 pathway is involved in the sequential progression from metaplastic Barrett’s esophagus (BE) to dysplasia to esophageal adenocarcinoma (EAC).METHODS:Fasting serum levels of insulin, glucose, IGF-1, insulin growth factor binding protein-1 (IGFBP1), and IGFBP3 were measured in 44 non-dysplastic, 9 low-grade dysplasia (LGD), 12 high-grade dysplasia (HGD), and 10 EAC subjects. Immunohistochemistry was performed on paraffin-embedded tissue derived from BE cases using rabbit monoclonal antibodies to p-mammalian target of rapamycin (mTOR) and p-AKT, mouse monoclonal antibody to Ki-67, and rabbit polyclonal antibody to p-insulin receptor substrate 1 (IRS1).RESULTS:Nineteen of 44 (43.2%) BE, 5/9 (55%) LGD, 8/12 (66.7%) HGD and EAC 7/10 (70%) cases showed strong staining for p-IRS1. A significantly higher proportion of HGD/EAC subjects showed p-IRS1 staining when compared with BE/LGD subjects, 63.6% vs. 41.5%, P<0.05. p-IRS1 immunostaining was moderately correlated with strong immunostaining of the downstream mediators p-AKT and p-mTOR (Spearman correlation coefficient=0.167 and 0.27 for p-IRS1/p-AKT and for p-IRS1/p-mTOR, respectively) and the proliferation marker Ki-67 (Spearman correlation coefficient=0.20, P=0.09). However, systemic levels of insulin, IGF-1, or IGF-2 were not associated with tissue immunostaining of p-IRS1.CONCLUSIONS:Activation of the insulin/IGF-1 pathway in BE may be associated with cellular proliferation and appears to have a role in the progression from metaplasia to cancer. The activation of the insulin/IGF-1 pathway at the tissue level is likely complex and does not have a simple association with systemic measures of insulin or IGF-1.

A nonrandomized trial of vitamin D supplementation for Barrett’s esophagus

Background Vitamin D deficiency may increase esophageal cancer risk. Vitamin D affects genes regulating proliferation, apoptosis, and differentiation and induces the tumor suppressor 15-hydroxyprostaglandin dehydrogenase (PGDH) in other cancers. This nonrandomized interventional study assessed effects of vitamin D supplementation in Barrett’s esophagus (BE). We hypothesized that vitamin D supplementation may have beneficial effects on gene expression including 15-PGDH in BE. Methods BE subjects with low grade or no dysplasia received vitamin D3 (cholecalciferol) 50,000 international units weekly plus a proton pump inhibitor for 12 weeks. Esophageal biopsies from normal plus metaplastic BE epithelium and blood samples were obtained before and after vitamin D supplementation. Serum 25-hydroxyvitamin D was measured to characterize vitamin D status. Esophageal gene expression was assessed using microarrays. Results 18 study subjects were evaluated. The baseline mean serum 25-hydroxyvitamin D level was 27 ng/mL (normal ≥30 ng/mL). After vitamin D supplementation, 25-hydroxyvitamin D levels rose significantly (median increase of 31.6 ng/mL, p<0.001). There were no significant changes in gene expression from esophageal squamous or Barrett’s epithelium including 15-PGDH after supplementation. Conclusion BE subjects were vitamin D insufficient. Despite improved vitamin D status with supplementation, no significant alterations in gene expression profiles were noted. If vitamin D supplementation benefits BE, a longer duration or higher dose of supplementation may be needed.

Red Meat Intake is Associated With Increased Risk of Barrett's Esophagus

Background: GEJ biopsies that contain inflamed squamous and columnar epithelium may represent distal esophageal columnar metaplasia or proximal gastritis (“carditis”). Pathologically, differentiation of these two disorders is difficult regardless of the presence or absence of goblet cells (GC). The aim of this study was to evaluate a wide variety of histologic features in GEJ biopsies, from a large prospective cohort of GERD patients, in order to determine their utility in predicting the presence of columnar-lined esophagus (CLE). Design: 2208 mucosal biopsies of the GEJ, from 552 GERD patients (M/F ratio: 305/247, mean age: 51 years), all of whom were endoscoped and interviewed prospectively as part of a large community clinic-based study of GERD patients in Washington state, were evaluated blindly for a wide variety of histologic features, such as mucosal and submucosal glands/ducts, multilayered epithelium (ME), type of glands (mucous, oxyntic, mixed), squamous islands, and buried columnar epithelium and correlated with the endoscopic evidence of, and length, of CLE, and with the presence of GC. The findings were also correlated with patients clinical risk factors for BE, such as gender, race, waist:hip ratio, smoking history, and body mass index (BMI). Results: Overall, 56% of patients revealed CLE. The prevalence rates of relevant histologic features in GEJ biopsies were as follows: submucosal glands (0.6%), ducts (4%), ME (17%), GC (26%), mucous glands only (20%), oxyntic glands only (25%), mixed mucous/oxyntic glands (52%), squamous islands (15%), buried columnar epithelium (19%). The presence of ME (p=0.03), GC (p=0.001), pure mucous glands (p= 25, at least weekly heartburn, and increased waist:hip ratio (male≥0.9, female≥0.8) were all associated with CLE. Conclusion: Certain histologic features, such as submucosal glands and/or ducts, ME, pure mucous glands, squamous islands, and buried columnar epithelium, when detected in GEJ biopsies of GERD patients, are indicative of the presence of CLE at endoscopy. Any of these findings, even in the absence of GC, should warrant clinical suspicion for CLE in endoscopically ambiguous cases.