Esophageal adenocarcinoma is increasing in frequency in the western world at an alarming rate and is unique because there is a clear metaplasia (Barrett's mucosa)/ dysplasia/carcinoma sequence. p53 malfunction arises as an early event in this carcinogenic process and has been demonstrated in patients with nondysplastic Barrett's metaplasia.
Immunohistochemical analysis revealed significantly more nuclear accumulation of beta-catenin and overexpression of cyclooxygenase-2 in patients with esophageal adenocarcinoma, compared with patients with cardiac carcinoma.
Barrett's esophagus is thought to progress to esophageal adenocarcinoma (EAC) through a stepwise progression with loss of CDKN2A followed by TP53 inactivation and aneuploidy.
Sections of formalin-fixed paraffin-embedded tissue from the initial biopsies of 275 patients with BM, who had no high-grade dysplasia (HGD) or oesophageal adenocarcinoma (EAC), were stained for p53 by immunohistochemistry.The mean follow-up was 41 months. p53-positive biopsies were divided into four groups: scattered positive cells, multifocal scattered positive cells, aggregates of positive cells, and multifocal aggregates of positive cells.
At 10 y, all abnormalities, except CDKN2A mutation and methylation, contributed to EA risk significantly by univariate analysis, ranging from 17p LOH (relative risk [RR] = 10.6; 95% confidence interval [CI] 5.2-21.3, p < 0.001) to 9p LOH (RR = 2.6; 95% CI 1.1-6.0, p = 0.03).
Indomethacin and parecoxib inhibit the growth of human esophageal adenocarcinoma xenografts in nude mice, which suggests a potential role for NSAIDs or selective COX-2 inhibitors for EAC chemotherapy.
Our study was initiated to test whether expression of COX isoforms (COX-1 and COX-2) is linked to expression of potent inducers of angiogenesis [vascular endothelial growth factor (VEGF)-A] and lymphangiogenesis (VEGF-C) in esophageal adenocarcinoma.
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.
Abnormal p16 expression (negative, cytoplasmic, or combined cytoplasmic and nuclear staining) was present in all categories, rising from 68% in BE without dysplasia to 100% in AdenoCa, with cytoplasmic staining only showing a significant correlation with the severity of dysplasia.
Patients with OAC and TP53 gene mutations have reduced overall survival compared with patients without these mutations, and this effect is independent of tumour stage.
COX-2 inhibition induces apoptosis and blocks proliferation in COX-2-expressing esophageal adenocarcinoma cells in vitro, and blocks angiogenesis in both in vivo and in vitro models.
We also correlated COX-2 and FGF-2 expression with clinico-pathologic findings and outcome in a well-characterized series of surgically resected EADC tissues.
The incidence of oesophageal adenocarcinoma is rising; to date, no susceptibility genes have been identified. p73, a novel p53 homologue, maps to chromosome 1p36, a region commonly deleted in oesophageal cancers. p73 shares some p53-like activity, but in addition, may also play a role in gastrointestinal epithelial inflammatory responses.
These results confirm the important role of Cox-2 amplification in the pathogenesis of esophageal adenocarcinoma, but the unexpected down-regulation of Cox-1 raises questions about its role in carcinogenesis.
Therefore, we examined whether acid increases methylation of p16 gene promoter and whether NADPH oxidase NOX5-S mediates acid-induced p16 hypermethylation in a Barrett's cell line BAR-T and an EA cell line OE33.