A. Dias Pereira

Verification and Unmasking of Widely Used Human Esophageal Adenocarcinoma Cell Lines

For decades, hundreds of different human tumor type-specific cell lines have been used in experimental cancer research as models for their respective tumors. The veracity of experimental results for a specific tumor type relies on the correct derivation of the cell line. In a worldwide effort, we verified the authenticity of all available esophageal adenocarcinoma (EAC) cell lines. We proved that the frequently used cell lines SEG-1 and BIC-1 and the SK-GT-5 cell line are in fact cell lines from other tumor types. Experimental results based on these contaminated cell lines have led to ongoing clinical trials recruiting EAC patients, to more than 100 scientific publications, and to at least three National Institutes of Health cancer research grants and 11 US patents, which emphasizes the importance of our findings. Widespread use of contaminated cell lines threatens the development of treatment strategies for EAC.

Short segments of Barrett’s epithelium and intestinal metaplasia in normal appearing oesophagogastric junctions: the same or two different entities?

Background—Endoscopic diagnosis of short segments of Barrett’s epithelium (SSBE) is difficult and its meaning in terms of the presence of specialised columnar epithelium (SCE) has not been prospectively evaluated. Aims—To evaluate the prevalence of SCE in patients with an endoscopic diagnosis of SSBE and in individuals with normal appearing oesophagogastric junctions, and to compare the clinical characteristics of these two groups. Patients—Thirty one patients with an endoscopic diagnosis of short Barrett’s oesophagus, less than 3 cm in length (group A), and 44 consecutive patients with normal appearing oesophagogastric junctions (group B). Methods—Multiple biopsies were performed in suspicious epithelium and at the oesophagogastric junction in groups A and B, respectively. Results—Age and sex distribution were similar in both groups. Reflux symptoms were more frequent in group A (p<0.001), as were endoscopic and histological signs of oesophagitis (p<0.0001 and p=0.001, respectively). SCE was found in 61.3% of group A patients compared with 25% in group B (p<0.002), with men predominating in group A while women were more frequent in group B (p=0.02). The differences in reflux symptoms and endoscopic/histological oesophagitis remained significant. Conclusions—These results show that endoscopic diagnosis of SSBE is associated with a high prevalence of SCE, significantly higher than that found in normal appearing oesophagogastric junctions. Differences between patients with SCE in the two groups suggest they may represent two different entities.

Is Barrett's Esophagus the Precursor of Most Adenocarcinomas of the Esophagus and Cardia? A Biochemical Study

OBJECTIVE To obtain biochemical evidence that Barretts esophagus (BE) is the precursor of most adenocarcinomas (Adc) of the esophagus and cardia. SUMMARY BACKGROUND DATA Based on morphologic data, BE was previously proposed as the precursor of most Adc of the esophagus. This hypothesis would receive strong support if biochemical evidence were found to demonstrate a pattern common to BE and Adc of the esophagus and cardia. METHODS We studied the presence of intestinal-type proteins sucrase-isomaltase (SI) and crypt Cell Antigen (CCAg) in BE, Barretts Adc, and esophageal-cardial Adc without BE. In each case specimens were collected from normal esophagus, stomach, tumor, and BE mucosa when present. To study related conditions, five specimens of peptic esophagitis and of squamous cell carcinoma were also analyzed. An indirect immunofluorescence technique was employed and sections were analyzed with laser confocal microscopy imaging. RESULTS Most Barretts mucosa specimens stained positively for SI (93%) and CCAg (89%). These proteins were detected in BE independently of the type of metaplasia, the coexistence of dysplasia, or the presence of associated Adc. SI and CCAg were present in 25 (96%) and 24 (92%) of the cases of Adc respectively. No statistical difference was detected in SI and CCAg expression between Adc samples with and without BE, between BE and Adc samples with or without BE, and between tumors located in the esophagus versus the cardia. No staining for these proteins was detected in stomach or esophageal mucosa, in submucosal glands of the esophagus, in peptic esophagitis or squamous cell carcinoma. CONCLUSION These data show that BE and Adc of the esophagus and cardia have a similar phenotype and support the hypothesis that most of these tumors probably originate from preexisting BE.

Chromosomal analysis of Barrett's cells: demonstration of instability and detection of the metaplastic lineage involved.

Barretts esophagus is lined by columnar and goblets cells with gastric and intestinal characteristics. Despite the association between goblet elements and malignancy, it was not demonstrated that other columnar cells lineages are not related to neoplasia. Chromosomal abnormalities were described in metaplasia adjacent to Barretts neoplasia, but it is unknown which metaplastic lineages are involved. This work assessed the frequency and the type of chromosomal abnormalities in Barretts esophagus without neoplasia and performed the identification of the metaplastic cells carrying chromosomal gains. Barretts esophagus biopsies were collected and processed for short-term cell culture and cytogenetic analysis. Combined immunofluorescence/fluorescence in situ hybridization was performed in cases exhibiting chromosomal gains by using antisera against intestinal (MUC2) and gastric (MUC5AC and MUC6) apomucins and chromosome pericentromeric alpha satellite DNA probes for the chromosomes involved. Each case was scored for the number of spots (0, 1, 2, >2) in 200 nonoverlapping nuclei. Columnar and goblet cells were separately assessed. Short-term cell cultures were achieved in 40/60 cases (67%). There were clonal abnormalities in 27/40 cases (68%) and tetraploid (4n) clones in 10/40 (25%). Structural alterations were detected in 14/40 (35%) with recurrent breakpoints at 1q21, 15q15 and 15q22. Numerical changes (trisomies 7 and 18 and loss of Y) occurred in 16/40 (40%). Gains of chromosomes 7 and 18 were more frequent in columnar than in goblet cells (9.8% vs 0.7% (P<0.05)) and (7.9 vs 1.9% (P<0.05)) respectively. These alterations were detected in cells exhibiting gastric as well as intestinal features and were more frequent in cells without apomucin production. Conclusions: (1) chromosomal instability is a common finding in Barretts esophagus without neoplasia. (2) The two metaplastic populations are committed, chromosomal gains being more frequent in columnar nongoblet than in goblet cells. (3) The two metaplastic phenotypes, gastric and intestinal, are equally involved.

Recurrent columnar-lined esophageal segments--study of the phenotypic characteristics using intestinal markers.

SUMMARY.  Barretts metaplasia is recognized by specialized columnar epithelium on the distal esophagus. The events involved in the transformation from squamous to Barretts epithelium remain unclear. The present study describes the characteristics observed during the recurrence of four cases of columnar-lined esophagus. Red velvet, gastric-like, esophageal mucosa was observed to develop above the anastomosis during follow-up of four patients submitted to surgery for esophageal and junctional adenocarcinoma. The areas of recurrence were associated with reflux symptoms and inflammation, with ulceration in two cases. Biopsies from the upper gastrointestinal endoscopies were examined histologically using periodic acid–Schiff/Alcian blue to detect acid mucins and a monoclonal antibody raised against the enterocytic enzyme sucrase–isomaltase. In all cases the recurrent columnar-lined segments displayed intestinal features recognized morphologically, histochemically, and/or immunohistochemically. There was no evidence of specialized columnar epithelium in three cases. The fourth patient developed specialized columnar epithelium during the tenth year of surveillance. The presence of AB-positive columnar cells was a frequent and early event. Columnar cells with unequivocal apical sucrase–isomaltase were observed only in association with specialized columnar epithelium. Four conclusions were reached: that the development of columnar-lined mucosa without specialized columnar epithelium may be the earliest event in Barretts metaplasia; that histochemistry is a useful method of recognizing a population with cryptic intestinal features; that acid mucin secretion precedes the production of enterocytic enzymes by columnar cells; and that a cell population with enterocytic differentiation, as assessed by sucrase–isomaltase expression, is associated with the development of specialized columnar epithelium. These characteristics of Barretts esophagus development are clinically relevant as they suggest that patients with columnar-lined esophagus without specialized columnar epithelium may acquire ‘true’ intestinal phenotype, justifying them being considered as high- risk patients.

Losses of Heterozygosity on Chromosomes 9p and 17p Are Frequent Events in Barrett’s Metaplasia Not Associated With Dysplasia or Adenocarcinoma

OBJECTIVE:Losses of heterozygosity (LOH) on chromosomes 9p and 17p frequently accompany malignant transformation of Barrett’s esophagus (BE). They have been reported in adenocarcinoma, dysplasia, and adjacent metaplasia of patients with long-segment BE (LSBE). This study aimed to evaluate and compare the frequency of LOH on 9p and 17p in patients with long- and short-segment BE (SSBE) without dysplasia or adenocarcinomaMETHODS:Matched metaplasia and blood DNA were evaluated for LOH on chromosomes 9p and 17p in patients with a previous diagnosis of BE and no dysplasia or cancer.RESULTS:We included 18 patients (12 long-segment BE and six short-segment BE). The overall prevalence of LOH was 61% (10 of 18), with no significant difference between LSBE (58%) and SSBE (50%). The frequencies of LOH on 9p and 17p were similar (35% and 39%, respectively), with 18% of the patients showing losses at both chromosomes.CONCLUSIONS:LOH on 9p and 17p are highly frequent events in BE, even in the absence of dysplasia and adenocarcinoma. The presence of these abnormalities in non-neoplastic epithelium suggests they might be useful markers for risk stratification within endoscopic surveillance programs.

Folate status, DNA methylation and colon cancer risk in inflammatory bowel disease

*Servi¢os de Gastrenterologia e Laborat6rio de Biologia Molecular ~Servi¢o de Patologia Morfol6gica, Instituto Portugu#s de Oncologia Francisco Gentil, Lisboa Portugal, tServi¢o Universit~rio de Medicina Interna e de Gastrenterologia e do Hospital Pulido Valente, Portugal (Correspondence to MC, Servigo de Gastrenterologia, Instituto Portugu#s de Oncologia Francisco Gentil, Rua Prof. Lima Basto, 1093 Lisboa Codex, Portugal)

Columnar‐lined oesophagus without intestinal metaplasia: results from a cohort with a mean follow‐up of 7 years

The definition of Barretts oesophagus lacks consensus, particularly the requirement of intestinal metaplasia for diagnosis. Scarce information exists on the prevalence and natural history of columnar‐lined oesophagus without intestinal metaplasia.

Gastric malt lymphoma: Analysis of a series of consecutive patients over 20 years

Introduction and aims Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is closely associated with Helicobacter pylori (HP) infection. Our aim was to evaluate demographic, clinical and endoscopic characteristics of gastric MALT lymphoma patients, as well as to analyse response to treatment and factors that affect complete remission (CR) and relapse. We also assessed the long-term prognosis. Methods The study involved a retrospective evaluation of consecutive patients admitted with gastric MALT lymphoma (1993–2013). Results A total of 144 patients (76 men; mean age 56) were included. At stage EI, 94/103 patients (92%) received HP eradication and 78 (83%) achieved CR after a mean period of 7 months (2–63 months) and 67 (86%) remained in CR after a mean follow-up time of 105 months. HP infection status (p = 0.004) and lymphoma localisation to the antrum plus body (p = 0.016) were associated with higher and lower CR rates, respectively. Relapse occurred in 11/78 (14%) patients after a mean period of 21 months. The absence of HP re-infection (p = 0.038), the need of only one eradication regimen (p = 0.009) and antrum lymphomas (p = 0.031) correlated with lower relapse rates. At stage EII, HP eradication was performed in 17/24 patients but only five experienced CR (30%). Among 16 patients diagnosed at stage EIV, nine achieved CR after chemotherapy ± surgery and 3/7 without remission died due to disease progression. The 5- and 10-year overall disease free survival rates were 90.5% and 79.1%, respectively. Conclusions Most patients were diagnosed at an early stage. Eradication therapy was highly effective in inducing complete remission. Long-term evaluation showed that the long-term prognosis was very favourable.

Esophageal stenosis with sloughing esophagitis: A curious manifestation of graft-vs-host disease.

We report a case of a 56-year-old woman with a history of allogenic bone marrow transplantation for two years, complaining with dysphagia and weight loss. Upper endoscopy revealed esophageal stenosis and extensive mucosa sloughing. Biopsies confirmed the diagnosis of graft-vs-host disease (GVHD). Balloon dilation, corticosteroids and cyclosporin resulted in marked clinical improvement. Gastrointestinal tract is involved in the majority of patients with chronic GVHD. Esophageal manifestations are rare and include vesiculobullous disease, ulceration, esophageal webs, casts or strictures. Sloughing esophagitis along with severe stenosis requiring endoscopic dilation has never been reported in this context.