These results indicate that p53 gene alterations contribute to the development of esophageal adenocarcinoma and precede the development of invasive carcinoma in patients with Barrett's esophagus.
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.
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.
Esophageal adenocarcinoma is characterized by evolution of punctuated and catastrophic somatic chromosomal alterations and high levels of overall mutations but few recurrently mutated genes aside from TP53.
17p (TP53) loss of heterozygosity (LOH) has been reported to be predictive of progression from Barrett's esophagus to esophageal adenocarcinoma, but the mechanism by which TP53 LOH develops is unknown.
In subgroup analyses based on pathological type, the Pro variant was significantly associated with an increased esophageal squamous cell carcinoma (ESCC) risk in all four genetic comparison models (ORPro vs. Arg=1.26, 95% CI: 1.08-1.47, POR=0.003; OR Recessive genetic model=1.42, 95% CI: 1.07-1.88, POR=0.015; ORDominant genetic model=1.25, 95% CI: 1.10-1.42, POR=0.001; ORHomozygote model=1.55, 95% CI: 1.14-2.10, POR=0.005), whereas the association between TP53Arg72Pro polymorphism and esophageal adenocarcinoma risk was still uncertain owing to the limited studies included in this meta-analysis.
The two types of tumor differed in the prevalence of TP53 mutations (31% in ADCC and 50% in ADCE) and of MDM2 gene amplification (19% in ADCC and 4% in ADCE), and in the pattern of expression of cytokeratin 7 (positive in 100% of ADCE and in 41% of ADCC) and cytokeratin 13 (positive in 81% of ADCE and in 36.5% of ADCC).
To investigate the role of NO in esophageal adenocarcinoma (EADC), we studied patterns of p53 mutations, expression of inducible nitric oxide synthase (iNOS) and the tissue accumulation of nitrotyrosine (NTS), a stable reaction product of NO and a marker for cellular protein damage, in human premalignant and malignant esophageal epithelia.
No significant differences were found for patients with EADC who had p53 mutations (n = 21) compared with patients with wild-type p53 (n = 33) with respect to selected clinicopathologic variables (age, gender, tumor grade, stage, alcohol, or tobacco consumption) and dietary intake of folate or vitamin B(6).
These TCRs mediated recognition of commercially available ovarian cancer, uterine carcinoma, and myeloma cell lines, as well as an NIH patient-derived esophageal adenocarcinoma line that endogenously expressed p53p.R175H and HLA-A*0201.
This observation suggests that TP53 gene mutation may be a relatively late event in the progression from nondysplastic Barrett's esophagus to adenocarcinoma of esophagus.
Sequence analysis of the p53 coding sequence in three EA cell lines (Seg-1, Bic-1, and Flo-1) that retain Fas protein within the cytoplasm, demonstrated that Seg-1 contained wt-p53, but mutations were found in Flo-1 and Bic-1 cell lines.
The size of a clone with a p16 lesion is not a significant predictor of esophageal adenocarcinoma when we controlled for p53 loss of heterozygosity status.
Barrett's esophagus (BE) can progress to dysplasia and esophageal adenocarcinoma (EAC), accompanied by mutations in TP53 that increase the stability of its product, p53.
The purpose of this study was to assess more accurately the incidence and types of p53 mutations in Barrett's esophagus (BE) with and without dysplasia and in esophageal adenocarcinoma, using pure preparations of epithelial cells obtained by laser capture microdissection (LCM).
A combination of 17p LOH, 9p LOH, and DNA content abnormalities provided better EA risk prediction than any single TP53, CDKN2A, or DNA content lesion alone.
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.
Parental tumour and MFD-1 carried four somatically acquired mutations in three recurrent mutated genes in OAC: TP53, ABCB1 and SEMA5A, not present in FLO-1 or OE33.
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.