Cyclooxygenase-2 and inducible nitric oxide synthase gene polymorphisms and risk of reflux esophagitis, Barrett's esophagus, and esophageal adenocarcinoma.

The incidence of esophageal adenocarcinoma has increased in recent years, and Barrett's esophagus is a recognized risk factor. Gastroesophageal reflux of acid and/or bile is linked to these conditions and to reflux esophagitis. Inflammatory disorders can lead to carcinogenesis through activation of "prosurvival genes," including cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Increased expression of these enzymes has been found in esophageal adenocarcinoma, Barrett's esophagus, and reflux esophagitis. Polymorphic variants in COX-2 and iNOS genes may be modifiers of risk of these conditions. In a population-based case-control study, we examined associations of the COX-2 8473 T>C and iNOS Ser(608) Leu (C>T) polymorphisms with risk of esophageal adenocarcinoma, Barrett's esophagus, and reflux esophagitis. Genomic DNA was extracted from blood samples collected from cases of esophageal adenocarcinoma (n = 210), Barrett's esophagus (n = 212), and reflux esophagitis (n = 230) and normal population controls frequency matched for age and sex (n = 248). Polymorphisms were genotyped using TaqMan allelic discrimination assays. Odds ratios and 95% confidence intervals were obtained from logistic regression models adjusted for potential confounding factors. The presence of at least one COX-2 8473 C allele was associated with a significantly increased risk of esophageal adenocarcinoma (adjusted odds ratio, 1.58; 95% confidence interval, 1.04-2.40). There was no significant association between this polymorphism and risk of Barrett's esophagus or reflux esophagitis or between the iNOS Ser 608 Leu polymorphism and risk of these esophageal conditions. Our study suggests that the COX-2 8473 C allele is a potential genetic marker for susceptibility to esophageal adenocarcinoma.     

Gains and amplifications of c-myc, EGFR, and 20.q13 loci in the no dysplasia-dysplasia-adenocarcinoma sequence of Barrett's esophagus

The progression of Barrett's esophagus to esophageal adenocarcinoma is often characterized by the accumulation of genetic abnormalities. The goal was to evaluate the copy number alterations of several oncogene loci, including 7p12 [epidermal growth factor receptor (EGFR)], 8q24 (c-myc), and 20q13 in the sequence of no dysplasia-dysplasia-adenocarcinoma of Barrett's esophagus. Fluorescence in situ hybridization with DNA probes for the centromeric region of chromosome 7 and the locus-specific regions of 7p12 (EGFR), 8q24 (c-myc), and 20q13 was applied on 99 brush cytology specimens of patients with Barrett's esophagus with different stages of dysplasia or esophageal adenocarcinoma. Gains (3-4 copies) of chromosome 17, 8q24 (c-myc), and 20q.13 loci were found in the low frequencies in nondysplastic Barrett's esophagus. Their frequencies increased with the stage of dysplasia and reached a high incidence in esophageal adenocarcinoma. Amplification (>4 copies) of at least 1 of the loci was observed in 14% of high-grade dysplasia and increased to 50% in esophageal adenocarcinoma (P = 0.015). The most frequently amplified locus was c-myc (18%), followed by 20q13 (13%) and EGFR (11%) in the high-grade dysplasia/esophageal adenocarcinoma cases. High amplification levels (>10 copies) of the loci were more frequent in esophageal adenocarcinoma (72%) compared with high-grade dysplasia (20%; P = 0.049). Amplifications of the c-myc, EGFR, and 20q12 loci may serve as diagnostic markers to identify patients with Barrett's esophagus with high-grade dysplasia or esophageal adenocarcinoma. Gains of the loci might be of value as prognostic markers because they are already present in nondysplasia cases and may precede the later event of the amplification as observed in high-grade dysplasia and esophageal adenocarcinoma.     

p53 in esophageal adenocarcinoma: a critical reassessment of mutation frequency and identification of 72Arg as the dominant allele

p53 alterations have been implicated in the progression of Barrett's esophagus to esophageal adenocarcinoma. However, the wide range of reported p53 alteration frequencies in esophageal adenocarcinoma makes using p53 as a marker of malignant transformation of Barrett's esophagus problematic. To determine the utility of p53 in Barrett's esophagus monitoring, the frequency of p53 alteration was critically reassessed using esophagectomy specimens of 40 cases of esophageal adenocarcinoma, including 10 with Barrett's esophagus and high-grade dysplasia, 8 with low-grade dysplasia and 7 with no dysplasia. DNA was extracted from tumor cells isolated by laser capture microdissection to maximize the assay sensitivity and mutations in exons 4-8 of p53 were determined by PCR direct sequencing. Mutations in p53 were identified in 75% (30/40) of the esophageal adenocarcinoma. p53 protein overexpression, detected by immunohistochemistry, was found in 58% (23/40) of the esophageal adenocarcinoma, 60% (6/10) of Barrett's esophagus with high-grade dysplasia, 12% (1/8) of Barrett's esophagus with low-grade dysplasia, and 0% of Barrett's esophagus without dysplasia. In addition to the mutations, a predominance of the 72Arg allele (89% homozygous) was found over the 72Pro allele in this series. p53 mutation frequency in this study was higher than reported in most of the literature and DNA sequencing detected more p53 alterations than immunohistochemical staining. However, p53 appeared to be a late marker in the neoplastic transformation, and no p53 change was found in approximately 25% of the adenocarcinoma. We concluded that p53 is insufficient as a single marker for Barrett's esophagus monitoring but may be useful as part of a panel due to its high specificity.     

Barrett's esophageal adenocarcinoma

Barrett's esophageal adenocarcinoma arises in Barrett's epithelium, which is grouped with gastro-esophageal reflux disease (GERD). Although the incidence of esophageal adenocarcinoma is very low in eastern countries, including Japan, it has been increasing markedly and is similar to that of squamous cell carcinoma in the western countries. Surveillance, endoscopic treatment, and chemoprevention using COX-2 inhibitors have recently been developed for dysplasia or mucosal cancer in Barrett's esophagus. Barrett's esophageal adenocarcinoma is diagnosed by endoscopy and by biopsy specimens pathologically. Surgical resection has been a mainstream treatment but definitive or neoadjuvant chemoradiotherapy has recently been performed.     

Progression of Barrett's metaplasia to adenocarcinoma is associated with the suppression of the transcriptional programs of epidermal differentiation

We did expressional profiling on 24 paired samples of normal esophageal epithelium, Barrett's metaplasia, and esophageal adenocarcinomas. Matching tissue samples representing the three different histologic types were obtained from each patient undergoing esophagectomy for adenocarcinoma. Our analysis compared the molecular changes accompanying the transformation of normal squamous epithelium with Barrett's esophagus and adenocarcinoma in individual patients rather than in a random cohort. We tested the hypothesis that expressional profiling may reveal gene sets that can be used as molecular markers of progression from normal esophageal epithelium to Barrett's esophagus and adenocarcinoma. Expressional profiling was done using U133A GeneChip (Affymetrix), which represent approximately two thirds of the human genome. The final selection of 214 genes permitted the discrimination of differential gene expression of normal esophageal squamous epithelium, Barrett's esophagus, and adenocarcinoma using two-dimensional hierarchical clustering of selected genes. These data indicate that transformation of Barrett's esophagus to adenocarcinoma is associated with suppression of the genes involved in epidermal differentiation, including genes in 1q21 loci and corresponding to the epidermal differentiation complex. Correlation analysis of genes concordantly expressed in Barrett's esophagus and adenocarcinoma revealed 21 genes that represent potential genetic markers of disease progression and pharmacologic targets for treatment intervention. PCR analysis of genes selected based on DNA array experiments revealed that estimation of the ratios of GATA6 to SPRR3 allows discrimination among normal esophageal epithelium, Barrett's dysplasia, and adenocarcinoma.     

Deoxycholate induces COX-2 expression via Erk1/2-, p38-MAPK and AP-1-dependent mechanisms in esophageal cancer cells

Background  

The progression from Barrett's metaplasia to adenocarcinoma is associated with the acquirement of an apoptosis-resistant phenotype. The bile acid deoxycholate (DCA) has been proposed to play an important role in the development of esophageal adenocarcinoma, but the precise molecular mechanisms remain undefined. The aim of this study was to investigate DCA-stimulated COX-2 signaling pathways and their possible contribution to deregulated cell survival and apoptosis in esophageal adenocarcinoma cells.     

Familiality in Barrett's esophagus, adenocarcinoma of the esophagus, and adenocarcinoma of the gastroesophageal junction.

BACKGROUND AND AIM: The familial aggregation of Barrett's esophagus, adenocarcinoma of the esophagus, and adenocarcinoma of the gastroesophageal junction, jointly termed familial Barrett's esophagus, may represent a complex genetic trait. The aim of this study was to determine the proportion of patients with these diseases who have familial Barrett's esophagus. METHODS: Information on gastroesophageal reflux symptoms, known risk factors for Barrett's esophagus, and family history of Barrett's esophagus and cancers, was collected at six hospitals using a structured questionnaire from probands with either long-segment Barrett's esophagus, adenocarcinoma of the esophagus, or adenocarcinoma of the gastroesophageal junction. Family history of Barrett's esophagus or esophageal cancer in a first- or second-degree relative was determined by reviewing medical records of all relatives reported to be affected. RESULTS: Seventy one of 411 (17.3%) probands reported an affected first- and/or second-degree relative. Upon review of medical records of the reportedly affected relatives, familial Barrett's esophagus was definitively determined in the case of 30 (7.3%) probands comprising 17 of 276 (6.2%) with Barrett's esophagus, 11 of 116 (9.5%) with adenocarcinoma of the esophagus, and 2 of 21 (9.5%) with adenocarcinoma of the gastroesophageal junction. The diagnosis in the relative reported by the proband to be affected was found not to be Barrett's esophagus or adenocarcinoma in 15 (3.6%) cases. The diagnosis could not be determined in 26 (6.3%) cases in which the proband reported an affected relative. There were no significant differences in age of disease onset, gender, race, or gastroesophageal reflux symptoms between definitive familial Barrett's esophagus probands and nonfamilial probands. CONCLUSION: Familial Barrett's esophagus can be confirmed in 7.3% of persons presenting with Barrett's esophagus, adenocarcinoma of the esophagus, or adenocarcinoma of the gastroesophageal junction.     

Indomethacin-induced apoptosis in esophageal adenocarcinoma cells involves upregulation of Bax and translocation of mitochondrial cytochrome C independent of COX-2 expression

The prolonged use of nonsteroidal anti-inflammatory drugs (NSAIDs) has been shown to exert a chemopreventive effect in esophageal and other gastrointestinal tumors. The precise mechanism by which this occurs, however, is unknown. While the inhibition of COX-2 as a potential explanation for this chemopreventive effect has gained a great deal of support, there also exists evidence supporting the presence of cyclooxygenase-independent pathways through which NSAIDs may exert their effects. In this study, immunohistochemical analysis of 29 Barrett's epithelial samples and 60 esophageal adenocarcinomas demonstrated abundant expression of the COX-2 protein in Barrett's epithelium, but marked heterogeneity of expression in esophageal adenocarcinomas. The three esophageal adenocarcinoma cell lines, Flo-1, Bic-1, and Seg-1, also demonstrated varying expression patterns for COX-1 and COX-2. Indomethacin induced apoptosis in all three cell lines, however, in both a time- and dose-dependent manner. In Flo-1 cells, which expressed almost undetectable levels of COX-1 and COX-2, and in Seg-1, which expressed significant levels of COX-1 and COX-2, indomethacin caused upregulation of the pro-apoptotic protein Bax. The upregulation of Bax was accompanied by the translocation of mitochondrial cytochrome c to the cytoplasm, and activation of caspase 9. Pre-treatment of both cell lines with the specific caspase 9 inhibitor, z-LEHD-FMK, as well as the broad-spectrum caspase inhibitor, z-VAD-FMK, blocked the effect of indomethacin-induced apoptosis. These data demonstrate that induction of apoptosis by indomethacin in esophageal adenocarcinoma cells is associated with the upregulation of Bax expression and mitochondrial cytochrome c translocation, and does not correlate with the expression of COX-2. This may have important implications for identifying new therapeutic targets in this deadly disease.     

No association between hOGG1, XRCC1, and XPD polymorphisms and risk of reflux esophagitis, Barrett's esophagus, or esophageal adenocarcinoma: results from the factors influencing the Barrett's adenocarcinoma relationship case-control study.

Reflux of gastric contents can lead to development of reflux esophagitis and Barrett's esophagus. Barrett's esophagus is a risk factor for esophageal adenocarcinoma. Damage to DNA may lead to carcinogenesis but is repaired through activation of pathways involving polymorphic enzymes, including human 8-oxoguanine glycosylase 1 (hOGG1), X-ray repair cross-complementing 1 (XRCC1), and xeroderma pigmentosum group D (XPD). Of the single nucleotide polymorphisms identified in these genes, hOGG1 Ser 326 Cys, XRCC1 Arg 399 Gln, and XPD Lys 751 Gln are particularly common in Caucasians and have been associated with lower DNA repair capacity. Small studies have reported associations with XPD Lys 751 Gln and esophageal adenocarcinoma. XRCC1 Arg 399 Gln has been linked to Barrett's esophagus and reflux esophagitis. In a population-based case-control study, we examined associations of the hOGG1 Ser 326 Cys, XRCC1 Arg 399 Gln, and XPD Lys 751 Gln polymorphisms with risk of esophageal adenocarcinoma, Barrett's esophagus, and reflux esophagitis. Genomic DNA was extracted from blood samples collected from cases of esophageal adenocarcinoma (n = 210), Barrett's esophagus (n = 212), reflux esophagitis (n = 230), and normal population controls frequency matched for age and sex (n = 248). Polymorphisms were genotyped using TaqMan allelic discrimination assays. Odds ratios and 95% confidence intervals were obtained from logistic regression models adjusted for potential confounding factors. There were no statistically significant associations between these polymorphisms and risk of esophageal adenocarcinoma, Barrett's esophagus, or reflux esophagitis.     

Nonsteroidal anti-inflammatory drugs and the esophageal inflammation-metaplasia-adenocarcinoma sequence

Observational studies suggest that nonsteroidal anti-inflammatory drugs (NSAIDs) reduce the risk of esophageal adenocarcinoma, but it is not known at what stage they may act in the esophageal inflammation-metaplasia-adenocarcinoma sequence. In an all-Ireland case-control study, we investigated the relationship between the use of NSAIDs and risk of reflux esophagitis, Barrett's esophagus, and esophageal adenocarcinoma. Patients with esophageal adenocarcinoma, long-segment Barrett's esophagus and population controls were recruited from throughout Ireland. Esophagitis patients were recruited from Northern Ireland only. Data were collected on known and potential risk factors for esophageal adenocarcinoma and on the use of NSAIDs, including aspirin, at least 1 year before interview. Associations between use of NSAIDs and the stages of the esophageal inflammation-metaplasia-adenocarcinoma sequence were estimated by multiple logistic regression. In total, 230 reflux esophagitis, 224 Barrett's esophagus, and 227 esophageal adenocarcinoma and 260 population controls were recruited. Use of aspirin and NSAIDs was associated with a reduced risk of Barrett's esophagus [odds ratio [OR; 95% confidence interval (95% CI)], 0.53 (0.31-0.90) and 0.40 (0.19-0.81), respectively] and esophageal adenocarcinoma [OR (95% CI), 0.57 (0.36-0.93) and 0.58 (0.31-1.08), respectively]. Barrett's esophagus and esophageal adenocarcinoma patients were less likely than controls to have used NSAIDs. Selection or recall bias may explain these results and the results of previous observational studies indicating a protective effect of NSAIDs against esophageal adenocarcinoma. If NSAIDs have a true protective effect on the esophageal inflammation-metaplasia-adenocarcinoma sequence, they may act early in the sequence.     

Surface expression of minichromosome maintenance proteins provides a novel method for detecting patients at risk for developing adenocarcinoma in Barrett's esophagus.

PURPOSE: The purpose is to determine whether a novel cell cycle marker, minichromosome maintenance protein 2 (Mcm2), predicted esophageal adenocarcinoma (AC) risk in Barrett's esophagus (BE) and whether this could be used in combination with a surface sampling method. EXPERIMENTAL DESIGN: Archival specimens [30 normal squamous esophagus (NE), 20 gastric antrum (GA), 13 duodenum (D2), 62 BE +/- dysplasia, and 16 (AC)] were stained for Mcm2. Sequential biopsies from nine patients who developed AC during surveillance were compared with 18 matched controls who did not progress. Prospective endoscopic cytological brushings (61 NE, 90 BE +/- dysplasia, and 11 AC) were scored as Mcm2 positive or negative. RESULTS: Mcm2 was not expressed on the luminal surface of NE, GA, and D2. In BE, the percentage of surface cells expressing Mcm2 correlated highly with the degree of dysplasia (P < 0.0001). In patients who developed AC, biopsies before dysplasia had higher Mcm2 expression than the matched control patients (mean, 28.4 and 3.4% positive cells, respectively, P < 0.0001). In the prospective cohort, the histopathological diagnosis of dysplasia or AC and the Mcm2-positive brushings were concordant in 91% of the patients (P < 0.005), and the results correlated with the frequency of cases with surface expression of Mcm2 in the retrospective study (P < 0.0001). CONCLUSIONS: Surface expression of Mcm2 can be used to detect dysplasia and AC, as well as patients with BE at risk for subsequent development of dysplasia and AC. A brushing technique combined with Mcm2 staining has the potential to be exploited in surveillance and screening protocols.     

Transcriptional activation of cyclooxygenase-2 by tumor suppressor p53 requires nuclear factor-kappaB

Overexpression of cyclooxygenase-2 (Cox-2) is thought to exert antiapoptotic effects in cancer. Here we show that the tumor suppressor p53 upregulated Cox-2 in esophageal and colon cancer cell lines by inducing the binding of nuclear factor-kappaB (NF-kappaB) to its response element in the COX-2 promoter. Inhibition of NF-kappaB prevented p53 induction of Cox-2 expression. Cooperation between p53 and NF-kappaB was required for activation of COX-2 promoter in response to daunomycin, a DNA-damaging agent. Pharmacological inhibition of Cox-2 enhanced apoptosis in response to daunomycin, in particular in cells containing active p53. In esophageal cancer, there was a correlation between Cox-2 expression and wild-type TP53 in Barrett's esophagus (BE) and in adenocarcinoma, but not in squamous cell carcinoma (P<0.01). These results suggest that p53 and NF-kappaB cooperate in upregulating Cox-2 expression, promoting cell survival in inflammatory precursor lesions such as BE.     

Barrett食道腺癌

Barrett食管是发展成为食道腺癌的危险因素。本文报告了Barrett食道腺癌12例,占同期食道癌发生率的12.9％,食道腺癌的33％。10例临床表现为吞咽困难,4例有长期胃食道返流病史,10例接受了外科治疗。结果支持Barrett食管是食道腺癌的癌前病变并提出应对Barrett食道进行监测。     

Barretts carcinoma in a 25-year-old man with point mutation of the p53 tumor suppressor gene

Barrett's esophagus is a recognized risk factor for adenocarcinoma of the esophagus. Dysplasia in Barrett's epithelium is considered a precursor to malignancy. Several tumor suppressor genes, including p53, have recently been implicated in the pathogenesis of esophageal adenocarcinoma. However, the interval between the development of Barrett's esophagus, dysplasia, and frank malignancy is usually very long. A case of adenocarcinoma of the esophagus arising from Barrett's esophagus in a 25-year-old man is discussed. Point mutation in exon 8 of p53 was discovered in this patient's tumor and surrounding dysplastic Barrett's mucosa. To our knowledge, this is the youngest reported case of Barrett's-associated esophageal adenocarcinoma in the medical literature. It suggests that acquired somatic mutations in tumor suppressor genes may occur early in life and that these mutations may contribute to the development of dysplasia and cancer in Barrett's esophagus.     

Analysis of Ki-67, p53 and Bcl-2 expression in the dysplasia-carcinoma sequence of Barrett's esophagus.

The grading of dysplasia in Barrett's esophagus has prognostic importance, however observer variation limits the reliability of simple histological analysis alone. We investigated Ki-67, p53 and Bcl-2 expression in Barrett's esophagus, in the sequence from Barrett's low-grade dysplasia to high-grade dysplasia and infiltrating adenocarcinoma. Forty-four esophagectomy specimens were utilized: 39 specimens with esophageal dysplasia and adenocarcinoma and 5 specimens with esophageal dysplasia only. This gave 83 sections (2 sections for specimens with dyplasia and carcinoma) examined from 44 patients. The sections were examined for Ki-67, p53 and Bcl-2 reactivity by immunohistochemistry. Low-grade dysplasia was present in 14 sections, high-grade dysplasia in 30 sections and carcinoma in 39 sections. Ki-67 expression occurred in 2 out of 14 (14%) sections with low-grade dysplasia, in 22 out of 30 (73%) sections with high-grade dysplasia and in 34 out of 39 (87%) sections with carcinoma (p<0.001). p53 protein expression was found in 1 of 14 (7%) sections with low-grade dysplasia, in 18 of 30 (60%) sections with high-grade dysplasia and in 33 of 39 (85%) sections with carcinoma (p<0.001). Expression of Bcl-2 was found in 11 of 14 (84%) sections with low-grade dysplasia but immunoreactivity was not seen in any section with high-grade dysplasia or Barrett's carcinoma. Our results indicate that overexpression of Ki-67, Bcl-2 protein and p53 mutations can be identified as early events during neoplastic progression in Barrett's esophagus. These data support the hypothesis that, in the progression of Barrett's metaplasia to adenocarcinoma, the balance of proliferation/apoptosis plays an important role.