Paola Parente

MicroRNA expression profiling in human Barrett's carcinogenesis.

Barretts esophagus (BE) is characterized by the native stratified squamous epithelium (N) lining the esophagus being replaced by a columnar epithelium with intestinal differentiation (Barretts mucosa; BM). BM is considered as the main risk factor for esophageal adenocarcinoma (Barretts adenocarcinoma; BAc). MicroRNAs (miRNAs) are a class of small noncoding RNAs that control gene expression by targeting messenger RNAs and they are reportedly dysregulated in BM. To test the hypothesis that a specific miRNA expression signature characterizes BM development and progression, we performed miRNA microarray analysis comparing native esophageal mucosa with all the phenotypic lesions seen in the Barretts carcinogenic process. Specimens were collected from 14 BE patients who had undergone esophagectomy, including: 14 with N, 14 with BM, 7 with low‐grade intraepithelial neoplasia, 5 with high‐grade intra‐epithelial neoplasia and 11 with BAc. Microarray findings were further validated by quantitive real‐time polymerase chain reaction and in situ hybridization analyses using a different series of consecutive cases (162 biopsy samples and 5 esophagectomies) of histologically proven, long‐segment BE. We identified a miRNA signature of Barretts carcinogenesis consisting of an increased expression of 6 miRNAs and a reduced expression of 7 miRNAs. To further support these results, we investigated target gene expression using the Oncomine database and/or immunohistochemical analysis. We found that target gene expression correlated significantly with miRNA dysregulation. Specific miRNAs are directly involved in BE progression to cancer. miRNA profiling significantly expands current knowledge on the molecular history of Barretts carcinogenesis, also identifying molecular markers of cancer progression.

Waist-to-Hip Ratio, but Not Body Mass Index, Is Associated With an Increased Risk of Barrett's Esophagus in White Men

BACKGROUND & AIMS Abdominal obesity increases the risk of gastroesophageal reflux disease (GERD) and also might contribute to the development of Barretts esophagus (BE), although results are inconsistent. We examined the effects of waist-to-hip ratio (WHR) and body mass index (BMI) on the risk of BE and investigated whether race, GERD symptoms, or hiatus hernia were involved. METHODS We conducted a case-control study using data from eligible patients who underwent elective esophagogastroduodenoscopy; 237 patients had BE and the other 1021 patients served as endoscopy controls. We also analyzed data and tissue samples from enrolled patients who were eligible for screening colonoscopies at a primary care clinic (colonoscopy controls, n = 479). All patients underwent esophagogastroduodenoscopy, completed a survey, and had anthropometric measurements taken. WHR was categorized as high if it was 0.9 or greater for men or 0.85 or greater for women. Data were analyzed with logistic regression. RESULTS There was no association between BMI and BE. However, more patients with BE had a high WHR (92.4%) than endoscopy controls (79.5%) or colonoscopy controls (84.6%) (P < .001 and P = .008, respectively). In adjusted analysis, patients with BE were 2-fold more likely to have a high WHR than endoscopy controls (odds ratio [OR], 1.93; 95% confidence interval [CI], 1.1-3.5), this association was stronger for patients with long-segment BE (OR, 2.81; 95% CI, 1.0-7.9). A high WHR was associated significantly with BE only in whites (OR, 2.5; 95% CI, 1.2-5.4), but not in blacks or Hispanics. GERD symptoms, hiatus hernia, or gastroesophageal valve flap grade could not account for the association. CONCLUSIONS High WHR, but not BMI, is associated with a significant increase in the risk of BE, especially long-segment BE and in whites. The association is not caused by GERD symptoms or hiatus hernia.

Association between Helicobacter pylori and Barrett's esophagus: a case-control study.

OBJECTIVES:The estimated association between Helicobacter pylori and Barretts esophagus (BE) has been heterogenous across previous studies. In this study, we aimed to examine the association between H. pylori and BE and to identify factors that may explain or modify this association.METHODS:We conducted a case–control study in which we used screening colonoscopy controls recruited from primary care clinics as our primary control group in order to minimize selection bias. All participants underwent an esophagogastroduodenoscopy with gastric mapping biopsies. We used logistic regression to obtain odds ratios (ORs) and 95% confidence intervals (CIs) to estimate the association between H. pylori and BE while controlling for confounders.RESULTS:We identified 218 cases and 439 controls. The overall OR for the association between H. pylori and BE after controlling for age and white race was 0.55 (95% CI: 0.35–0.84). We observed an even stronger inverse association (OR: 0.28; 95% CI: 0.15, 0.50) among participants with corpus atrophy or antisecretory drug use ≥1 time per week (factors thought to lower gastric acidity), and no inverse association in patients without these factors (OR: 1.32; 95% CI: 0.66, 2.63).CONCLUSIONS:The association between H. pylori and a decreased risk for BE appears to occur in patients with factors that would likely lower gastric acidity (corpus atrophy or taking antisecretory drugs at least once a week).

Long-Term Follow-up of Barrett’s Epithelium: Medical Versus Antireflux Surgical Therapy

BackgroundBarrett’s esophagus (BE) is the most serious complication of GERD. In BE patients, this observational study compares the effects of antireflux surgery versus antisecretory medical therapy.MethodsOverall, 89 BE patients (long BE = 45; short BE = 44) were considered: 45 patients underwent antireflux surgery and 44 underwent medical therapy. At both initial and follow-up endoscopy, symptoms were assessed using a detailed questionnaire; BE phenotypic changes [intestinal metaplasia (IM) presence/type, Cdx2 expression] were assessed by histology (H&E), histochemistry (HID), and immunohistochemistry. Surgical failures were defined as follows: (1) abnormal 24-h pH monitoring results after surgery, (2) endoscopically evident recurrent esophagitis, and (3) recurrent hiatal hernia or slipped fundoplication on endoscopy or barium swallow.ResultsReversion of IM was observed in 12/44 SSBE and 0/45 LSBE patients (p < 0.01). Reversion was more frequently observed after effective antireflux surgery than after medical treatment (p = 0.04). In patients with no further evidence of IM after therapy, Cdx2 expression was also absent (p = 0.02). The extent of IM was reduced, and the IM phenotype improved in SSBE patients after surgery.ConclusionsPatients with short BE (but not those with long BE) may benefit from surgically reducing the esophagus’ exposure to GE reflux; among these patients, successful surgery carries a higher IM reversion rate than medical treatment.

Programmed cell death 4 (PDCD4) expression during multistep Barrett's carcinogenesis

Aim To test the contribution of programmed cell death 4 (PDCD4) tumour suppressor gene in Barretts carcinogenesis. Methods PDCD4 immunohistochemical expression was assessed in 88 biopsy samples obtained from histologically proven long-segment Barretts mucosa (BM; 25 non-intestinal columnar metaplasia, 25 intestinal metaplasia (IM), 16 low-grade intraepithelial neoplasia (LG-IEN), 12 high-grade IEN (HG-IEN) and 10 Barretts adenocarcinoma (BAc)). As controls, 25 additional samples of native oesophageal mucosa (N) were obtained from patients with dyspepsia. To further support the data, the expression levels of miR-21, an important PDCD4 expression regulator, in 14 N, 5 HG-IEN and 11 BAc samples were determined by quantitative real-time PCR analysis. Results PDCD4 immunostaining decreased progressively and significantly with the progression of the phenotypic changes occurring during Barretts carcinogenesis (p<0.001). Normal basal squamous epithelial layers featured strong PDCD4 nuclear immunoreaction (mostly coexisting with weak–moderate cytoplasmic staining). Non-intestinal columnar metaplasia and intestinal metaplasia preserved a strong nuclear immunostaining; conversely, a significant decrease in PDCD4 nuclear expression was seen in dysplastic (LG-IEN and HG-IEN) and neoplastic lesions. Weak–moderate cytoplasmic immunostaining was evident in cases of LG-IEN, while HG-IEN and BAc samples showed weak cytoplasmic or no protein expression. As expected, miR-21 expression was significantly upregulated in HG-IEN and BAc samples, consistently with PDCD4 dysregulation. Conclusions These data support a significant role for PDCD4 downregulation in the progression of BM to BAc, and confirm miR-21 as a negative regulator of PDCD4 in vivo. Further efforts are needed to validate PDCD4 as a potential prognostic marker in patients with Barretts oesophagus.

Aurora kinase A in Barrett’s carcinogenesis

In Barretts mucosa, both aneuploidy and TP53 mutations are consistently recognized as markers of an increased risk of Barretts adenocarcinoma. Overexpression of the mitotic kinase encoding gene (AURKA) results in chromosome instability (assessed from the micronuclei count) and ultimately in aneuploidy. Eighty-seven esophageal biopsy samples representative of all the phenotypic lesions occurring in the multistep process of Barretts carcinogenesis (gastric metaplasia in 25, intestinal metaplasia in 25, low-grade intraepithelial neoplasia in 16, high-grade intraepithelial neoplasia in 11, and Barretts adenocarcinoma in 10) were obtained from long segments of Barretts mucosa. Twenty-five additional biopsy samples of native esophageal mucosa were used for control purposes. In all tissue samples, the immunohistochemical expression of both AURKA and TP53 gene products was scored; and the micronuclei index was calculated. AURKA immunostaining increased progressively and significantly along with dedifferentiation of the histologic phenotype (P < .001). Nine of 10 Barretts adenocarcinomas showed AURKA immunostaining. AURKA expression correlated significantly with p53 expression and the micronuclei index (both Ps < .001). AURKA overexpression is significantly associated with Barretts mucosa progressing to Barretts adenocarcinoma and contributes to esophageal carcinogenesis via chromosome instability. The identification of AURKA as a novel molecular target of cancer progression in Barretts mucosa provides a lead for the development of new therapeutic approaches in Barretts mucosa patients.

The prevalence of oesophageal eosinophilia and eosinophilic oesophagitis: a prospective study in unselected patients presenting to endoscopy.

Oesophageal eosinophilia (EE) is encountered in clinical practice as oesophageal biopsies are being obtained in patients with GI symptoms other than classical symptoms of eosinophilic oesophagitis (EoE). The prevalence, determinants and clinical relevance of EE identified irrespective of symptoms are unclear.

Dietary consumption of meat, fat, animal products and advanced glycation end-products and the risk of Barrett's oesophagus

Advanced glycation end‐products (AGEs) are found in high quantity in high‐fat foods and meat cooked at high temperature. AGEs have been shown to contribute to chronic inflammation and oxidative stress in humans.

Keap1/Nrf2 pathway in kidney cancer: frequent methylation of KEAP1 gene promoter in clear renal cell carcinoma

The Keap1/Nrf2 pathway is a master regulator of the cellular redox state through the induction of several antioxidant defence genes implicated in chemotherapeutic drugs resistance of tumor cells. An increasing body of evidence supports a key role for Keap1/Nrf2 pathway in kidney diseases and renal cell carcinoma (RCC), but data concerning the molecular basis and the clinical effect of its deregulation remain incomplete. Here we present a molecular profiling of the KEAP1 and NFE2L2 genes in five different Renal Cell Carcinoma histotypes by analysing 89 tumor/normal paired tissues (clear cell Renal Carcinoma, ccRCCs; Oncocytomas; Papillary Renal Cell Carcinoma Type 1, PRCC1; Papillary Renal Cell Carcinoma Type 2, PRCC2; and Chromophobe Cell Carcinoma). A tumor-specific DNA methylation of the KEAP1 gene promoter region was found as a specific feature of the ccRCC subtype (18/37, 48.6%) and a direct correlation with mRNA levels was confirmed by in vitro 5-azacytidine treatment. Analysis of an independent data set of 481 ccRCC and 265 PRCC tumors corroborates our results and multivariate analysis reveals a significant correlation among ccRCCs epigenetic KEAP1 silencing and staging, grading and overall survival. Our molecular results show for the the first time the epigenetic silencing of KEAP1 promoter as the leading mechanism for modulation of KEAP1 expression in ccRCCs and corroborate the driver role of Keap1/Nrf2 axis deregulation with potential new function as independent epigenetic prognostic marker in renal cell carcinoma.

Intestinal or gastric? The unsolved dilemma of Barrett's metaplasia

biopsy samples was higher for the IM-positive group (IM positive = 6.0, range = 1-37, versus IM negative = 2.0, range = 1-18), and the IM-positive cases were associated with a significantly longer Barretts segment (IM positive = 3.5 ± 2.9 versus IM negative = 2.0 ± 1.7). Overall, the prevalence of neoplasia (both invasive and noninvasive [NiN]) in the population considered was 9% (30 cases: 7 invasive adenocarcinomas, 4 high-grade NiN, 7 low-grade NiN, and 12 indefinite for NiN lesions). None of these 30 cases was identified in the IM-negative group, but 3 cases of neoplasia (10%; 1 adenocarcinoma, 1 HG-NiN, and 1 indefinite for NiN) were identified in IM-negative biopsy samples. Our data confirm the “biologic impact” of IM in patients with BM. On the other hand, as in Takubos study, our observations provide evidence that even IM-negative BM is associated with cancer risk. We are still far from a welldefined characterization of the Barretts carcinogenesis, and cancer origin via stem cells can theoretically reconcile apparently divergent positions. Focusing on the BMassociated cancer risk, we have established a prospective multicenter trial [5], including clinical, pathological, and molecular branches; we hope that such an integrated effort will contribute to our understanding on the puzzling issue of Barretts carcinogenesis.