Immunohistochemical presentation in non-malignant and malignant Barrett's epithelium

An analysis of esophagectomy and other techniques in the management of high-grade dysplasia of Barrett's esophagus

Barrett's esophageal (BE) metaplasia is a premalignant condition of the distal esophagus that develops as a consequence of gastroesophageal reflux disease. The progression to carcinogenesis results from progressive dysplastic changes of the metaplastic epithelium through low-grade and then high-grade dysplasia (HGD) to eventually adenocarcinoma of the esophagus. The management of HGD is controversial with proponents for each of the three major management strategies: endoscopic surveillance, endoscopic ablative therapies, and esophagectomy. The aim of the study was to define and discuss the various management strategies of HGD arising from BE metaplasia. There is a paucity of randomized controlled data from which to draw definitive conclusions. All strategies for the management of HGD are reasonable options and are complimentary. BE with HGD is a malignant lesion. A multidisciplinary approach individualizing therapy should be undertaken when possible. Esophageal resection should be reserved for otherwise healthy patients. Endoscopic techniques are viable alternatives to surgery.

Increased p53 expression in the malignant transformation of Barrett's esophagus is accompanied by an upward shift of the proliferative compartment

Neoplastic progression in Barrett's esophagus (BE) occurs by a multistep process associated with early molecular and morphological changes. This study evaluated cell proliferation and p53 expression and their correlation in the development and progression of esophageal adenocarcinoma. PCNA and p53 expressions were analyzed in biopsy samples by immunohistochemistry including patients with reflux esophagitis, BE, BE with concomitant esophagitis, Barrett's dysplasia, esophageal adenocarcinoma and a control group without any histological changes. Progressive increase in cell proliferation and p53 expression was found in the sequence of malignant transformation of the esophageal mucosa. While cell proliferation was significantly lower in the control group compared with all other groups, there was no increase in p53 expression of esophageal tissues that were negative for dysplasia. Dysplastic BE tissues revealed significantly higher cell proliferation and p53 expression levels compared to BE, reflux esophagitis or BE with concomitant esophagitis. Both, cell proliferation and p53 expression were significantly higher in adenocarcinoma compared to BE or Barrett's dysplasia. Interestingly, while just BE with concomitant esophagitis showed significantly higher p53 expression levels than BE, both, BE with concomitant esophagitis and reflux esophagitis revealed significantly higher cell proliferation levels compared to BE. Alterations of cell proliferation and p53 expression showed a strong correlation. Simultaneous activation of cell proliferation and p53 expression strongly suggest their association with esophageal epithelial tumor genesis and particularly, their specific role in the biology of esophageal adenocarcinoma. Quantification of these parameters in BE is thought to be useful to identify patients at higher risk for progression to adenocarcinoma.

Modulation of intracellular trafficking regulates cell intercalation in the Drosophila trachea

Through intercalation, a fundamental mechanism underlying elongation during morphogenesis, epithelial cells exchange places in a spatially oriented manner. Epithelial cells are tightly coupled through distinct intercellular junctions, including adherens junctions. Whether trafficking-mediated regulation of adhesion through adherens junctions modulates intercalation in vivo remains controversial. In Drosophila melanogaster, cells in most branches intercalate during tracheal development. However, Wingless (Wg)-promoted expression of the transcription factor Spalt (Sal) in the dorsal trunk inhibits intercalation by an unknown mechanism. Here we have examined the role of trafficking in tracheal intercalation and show that it requires endocytosis, whereas it is opposed by Rab11-mediated recycling in the dorsal trunk. Subapical Rab11 accumulation is enhanced by sal and elevated Rab11-mediated recycling occurs in the dorsal trunk, suggesting that upregulation of Rab11 is one way in which sal inhibits intercalation. We found that dRip11, which regulates Rab11 localization and function, is regulated by sal and can modulate intercalation. Finally, we provide evidence that levels of E-cadherin (DE-cad), an adherens junction component and Rab11-compartment cargo, are dynamically regulated by trafficking during tracheal development, and that such regulation modulates intercalation. Our work suggests a mechanism by which trafficking of adhesion molecules regulates intercalation, and shows how this mechanism can be modulated in vivo to influence cell behaviour.

Repeated exposure to acid and bile selectively induces colonic phenotype expression in a heterogeneous Barrett's epithelial cell line

Barrett's epithelium is a precancerous, specialized columnar metaplasia in the distal esophagus. We demonstrate the changes in cellular phenotype in a non-neoplastic Barrett's cell line (BAR-T), following exposure to acid and bile salt, the two important components of gastroesophageal refluxate. Cell phenotypes in BAR-T cell line were quantified by fluorescence-activated cell sorting (FACS) using monoclonal antibodies against markers: cytokeratin 8/18 (CK8/18) for columnar, CK4 for squamous, mAbDas-1 for colonic epithelial cell phenotype and p75NTR for esophageal progenitors. Cells were exposed for 5 min each day to 200 microM glycochenodeoxycholic acid at pH 4, pH 6 and pH 7.4 or only to acid (pH 4) for up to 6 weeks. The BAR-T cell line comprised 35+/-5.2% CK8/18, 32+/-3.5% mAbDas-1, 9.5+/-3% CK4 and 4+/-2.5% p75NTR-positive cells. Single exposure to acid and or bile did not change cell phenotypes. However, chronic treatment for at least 2 weeks significantly enhanced (P<0.05) the expression of colonic phenotype and CK8/18-positive cells, as evidenced by FACS analysis. Bile salt at pH 4 and bile salt followed by acid (pH 4) in succession were the strongest stimulators (P<0.01) for induction of colonic phenotype cells. Squamous (CK4(+)) phenotype did not change by the treatments. Cox-2 expression was induced after acute treatment and increased to twofold during chronic treatment, particularly in response to acidic pH. We conclude that BAR-T cells can be utilized as an 'in vitro' model to study the effect of environmental factors and their influence on the cellular phenotype and molecular changes in the pathogenesis of esophageal cancer.

Alterations of glutathione S-transferase and matrix metalloproteinase-9 expressions are early events in esophageal carcinogenesis

AIM

To investigate the role of glutathione S-transferase (GST) and matrix metalloproteinase-9 (MMP-9) expressions in the development and progression of reflux esophagitis-Barrett's metaplasia-dysplasia-adenocarcinoma sequence in the esophagus.

METHODS

GST and MMP-9 expressions were analyzed in 51 paraffin-embedded tissue samples by immunohistochemistry including patients with reflux esophagitis (n = 7), Barrett's metaplasia (n = 14), Barrett and esophagitis (n = 8), Barrett and dysplasia (n = 7), esophageal adenocarcinoma (n = 8) and a control group without any histological changes (n = 7). Immunostaining was determined semiquantitatively. Statistical analysis with one-way ANOVA, LSD test and correlation analysis were performed. P value of < 0.05 was considered significant.

RESULTS

GST expression was significantly higher while MMP-9 expression was significantly lower in control group compared to Barrett's metaplasia and the other groups. No major changes were observed between Barrett, esophagitis, and Barrett and concomitant esophagitis. Barrett and concomitant dysplasia, and adenocarcinoma revealed a significant lower expression of GST and higher levels of MMP-9 compared to all other groups. Adenocarcinoma showed almost no expression of GST and significantly higher levels of MMP-9 than Barrett and concomitant dysplasia. Alterations of GST and MMP-9 were inversely correlated (r = -0.82).

CONCLUSION

Decreased GST and increased expression of MMP-9 in Barrett's metaplasia-dysplasia-adenocarcinoma sequence as compared to normal tissue suggest their association with esophageal tumorigenesis. Loss of GST and gain of MMP-9 in Barrett with dysplasia compared to non-dysplastic metaplasia indicate that these alterations may be early events in carcinogenesis. Quantification of these parameters in Barrett's esophagus might be useful to identify patients at higher risk for progression to cancer.

HER-2 overexpression (3+) in patients with squamous cell esophageal carcinoma correlates with poorer survival

The incidence of esophageal carcinoma is increasing worldwide. In Sweden, approximately 400 patients are diagnosed each year. The present study retrospectively investigates survival in 97 patients with esophageal carcinoma in regard to their HER-2 status as examined by immunohistochemistry (IHC) and chromogen in situ hybridization (CISH). Sixty-eight patients had localised disease and 29 patients had advanced disease. Seventy patients had squamous cell carcinoma, and nine of these patients (13%) had HER-2 overexpression (3+). Eight (30%) of 27 adenocarcinoma patients overexpressed (3+) HER-2. In patients overexpressing (3+) HER-2 a statistical trend towards poorer survival was observed (P = 0.057). In squamous cell carcinoma patients, HER-2 overexpression (3+) correlated with poorer survival (P = 0.035), whereas in adenocarcinoma patients, HER-2 status (3+) did not. HER-2 amplification according to CISH was present in five (two squamous cell carcinomas and three adenocarcinomas) out of 17 HER-2 overexpressing (3+) tumours. In conclusion, HER-2 overexpression (3+) seems to be associated with poorer survival in esophageal carcinomas, especially in patients with squamous cell esophageal carcinoma.

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p27 and Barrett's esophagus: a review*

The rising prevalence of Barrett's esophagus and Barrett's associated adenocarcinoma in the Western world has stimulated increasing interest in this disease. This has resulted in a plethora of articles concerning its molecular biology, but the tumor suppressor gene, p27, has received little attention. In this article, we review the literature concerning the role of p27 in Barrett's esophagus and its malignant transformation, and we evaluate its possible role as an important clinical biomarker, as well as potential chemopreventive clinical agents aimed at substituting its antitumoral activity.