Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report a case of gastritis cystica polyposa (GCP) that developed in association with a small stump carcinoma. The patient had had distal gastrectomy for peptic ulcer 33 years prior to the present illness. Total gastrectomy was carried out for the stump carcinoma of the remnant stomach, followed by Roux-en-Y anastomosis. Histological examination revealed that the cancer was associated with a GCP lesion in its neighborhood. The resected stomach was subjected to a cell kinetics study and p53 gene analysis, as GCPs are thought to have a high potential for carcinogenesis. The GCP mucosae, as well cancer tissues and remnant mucosae obtained from the same specimens, were investigated and compared. We found that cell kinetics, as measured by a Ki-67 labeling index count, was more accelerated in the GCP than in the remnant mucosa, and that p53 gene aberrations, including both mutations and deletions, took place in the GCP lesion. As the p53 gene is considered to be recessive, in principle, its tumor suppressive activity is lost only when gene aberration, either mutation or deletion, occurs concurrently or successively in both alleles. It was of interest to us that a benign lesion such as GCP had, in this instance, already developed both gene aberrations, strongly suggesting a precancerous nature for this disease.
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PMID:Gastritis cystica polyposa associated with a gastric stump carcinoma, with special reference to cell kinetics and p53 gene aberrations. 1198 32

Helicobacter pylori (H. pylori) infection is associated with changes in epithelial turnover, through their significance of these in gastric carcinogenesis is still controversial. The purpose of this study was to determine the influence of H. pylori infection on cell proliferation and the relation with the cell-cycle regulators, and finally to provide insights into the mechanism by which H. pylori may lead to gastric carcinogenesis. We investigated Ki-67, p53, p21(Waf1/Cip1), cyclin D1 expression in 55 patients with H. pylori gastritis, and compared the results with patients those of non-H. pylori gastritis patients (n=21), gastric adenocarcinoma patients (n=8) and samples with normal gastric mucosa (n=12). Gastric biopsies were histologically evaluated for inflammatory reaction, intestinal metaplasia and atrophy according to the Sydney system. Overexpression of Ki-67, p53, p21(Waf1/Cip1) and cyclin D1 was found in H. pylori gastritis patients (32.7%, 10.9%, 20.0% and 7.3%, respectively), whereas only scattered expression in cells in the neck region of the crypts, but no overexpression was found in gastric antral epithelial cells in biopsy specimens from patients with non-H. pylori gastritis and noninflammed mucosa. A significant relationship was found between the grade of H. pylori colonization and Ki-67, p53, p21(Waf1/Cip1) and cyclin D1 expression. Expression was significantly higher in patients with intestinal metaplasia with atrophy, whereas no overexpression was found in patients without intestinal metaplasia with atrophy (p=0.05). H. pylori infection is associated with increased cell proliferation, increased epithelial DNA damage, and atrophy, which might contribute to the development of gastric cancer. Even if the exact mechanism has not been elucidated yet, our results suggest that H. pylori infection acts as a cofactor in gastric carcinogenesis.
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PMID:Expression of cell-cycle related proteins in Helicobacter pylori gastritis and association with gastric carcinoma. 1208 13

p53 codon 72, which produces variant proteins with an arginine (Arg) or proline (Pro), has been reported to be associated with cancers of the lung, esophagus and cervix. However, there have been no reports on the p53 codon 72 polymorphism in gastric cancer susceptibility in patients with Helicobacter pylori-associated chronic gastritis (H. pylori-CG). We, therefore, examined the polymorphism in 117 gastric cancer patients (72 intestinal type and 45 diffuse type) with H. pylori-CG and 116 H. pylori-CG patients without gastric cancer as controls. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was performed to analyze the p53 codon 72 polymorphism. The crude genotypic frequencies in the gastric cancer patients were similar to those of the controls. However, when gastric cancers were classified by histologic subtype, the Pro/Pro was more frequent in the patients with diffuse type gastric cancer than in the controls (22.2% of cases vs. 12.1% of controls). The Pro/Pro genotype was associated with a 2.98-fold higher risk of diffuse-type cancer compared to the Arg/Arg genotype (95% confidence interval [CI] 1.07-8.32, p = 0.038). These results suggest that the Pro/Pro genotype at p53 codon 72 contributes to susceptibility for diffuse-type gastric cancer in patients with H. pylori-CG. The p53 codon 72 polymorphism may serve as the genetic marker for the risk assessment of the diffuse-type gastric cancer development in patients with H. pylori-CG.
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PMID:p53 Codon 72 polymorphism in gastric cancer susceptibility in patients with Helicobacter pylori-associated chronic gastritis. 1211 45

Precursor lesions in the GIT include flat dysplasias, adenomas, dysplasia superimposed on nonneoplastic polyps, endocrine cell dysplasia, ACF, and condyloma accuminatum. Interobserver variability can be a problem in reporting dysplasia, and ancillary techniques including flow cytometry, image analysis, proliferation markers, and examination for p53 expression can help in this task. Squamous dysplasia seen in the esophagus and anus is graded on either a two-tiered or three-tiered system largely based on the extent of mucosal involvement. Glandular dysplasia is morphologically similar whether seen as an adenomatous polyp or within the setting of Barrett's esophagus, atrophic gastritis, or idiopathic inflammatory bowel disease. The distinction between LGD and HGD in glandular mucosa is based on the severity of cytologic and architectural distortion. Type I dysplasia is the classic adenomatous pattern seen most commonly and recognized by the presence of elongate hyperchromatic stratified nuclei. Type II, the nonadenomatous variant, contains vesicular nuclei and alteration in nuclear size and shape. Nonantral endocrine dysplasia in the stomach is seen in the setting of corporal predominant atrophic chronic gastritis and Zollinger-Ellison syndrome with Multiple Endocrine Neoplasia syndrome type I. Condyloma accuminatum is a HPV-related lesion most commonly seen in men practicing anal intercourse. Superimposed squamous dysplasia can be seen with HGD most frequently in the HIV-positive population. Recognition of the different classification systems of dysplasia, the most frequent settings in which these lesions are found, and their natural history is important for all practicing gastroenterologists and pathologists.
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PMID:Histologic precursors of gastrointestinal tract malignancy. 1213 10

Helicobacter pylori infection is the main cause of chronic gastritis. The infection has been linked to altered proliferative activity and changes in various cell cycle regulating proteins. To determine, in a general population sample, the proliferative activity and expression of p53 and p21 in males and females of different age groups with and without H. pylori-associated chronic gastritis, gastric biopsies from 273 subjects (188 with and 85 without H. pylori infection) randomly selected from a general population were examined immunohistochemically for Ki-67, p53, and p21. One thousand epithelial cells, including the surface, neck, and glandular areas, were counted in both the corpus and the antrum. Results are expressed as the percentage of positive cells. Subjects with H. pylori infection showed significantly increased proliferative activity and expression of p53 compared to uninfected individuals. Regarding the expression of p21, no difference was detected. Multiple linear regression analysis showed significant associations between chronic inflammation or inflammatory activity, on the one hand, and the degree of proliferation in both the corpus and the antrum, on the other hand. In the antrum, the degree of H. pylori colonization was related to the expression of p53. H. pylori seems to cause increased proliferation and increased expression of p53 (but not p21) in the gastric mucosa, neither of which is age or sex dependent. The proliferative activity is related mainly to events associated with inflammation, while the expression of p53 in the antrum is associated with the degree of H. pylori infection. The action of p53 appears to be independent of p21 activity.
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PMID:Gastric epithelial proliferation and p53 and p21 expression in a general population sample: relations to age, sex, and mucosal changes associated with H. pylori infection. 1214 17

Of 987 cases of gastric adenocarcinoma seen at Nagoya University School of Medicine, we found 6 rare, extremely well-differentiated advanced gastric adenocarcinomas that could not be diagnosed as malignant tumors with only H&E staining, even with repeated biopsies under preoperative endoscopy. The aim of this study was to determine whether an immunohistochemical method using p53 and Ki-67 antibody would be helpfulfor preoperative pathologic diagnosis. The cancer control cases were 16 cases of ordinary well-differentiated advanced gastric adenocarcinoma, while the gastritis control cases were 22 cases of Helicobacter pylori-positive chronic gastritis. The p53 labeling index and the localization of Ki-67+ cells showed that the special adenocarcinomas in biopsy specimens were distinct from the surrounding normal mucosa and chronic gastritis, but not from the cancer control cases. These methods are useful markers for preoperative pathologic diagnosis of extremely well-differentiated gastric adenocarcinoma, which sometimes is confused with regenerative atypical glands before operation.
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PMID:Usefulness of p53 and Ki-67 immunohistochemical analysis for preoperative diagnosis of extremely well-differentiated gastric adenocarcinoma. 1242 87

It has been suggested that certain histological criteria may serve to indicate a good prognosis in patients with esophageal carcinoma. These include absence of subepithelial extension of the carcinoma cells, stage no higher than m2, and no neoplastic involvement near the resection margin. As endoscopic mucosal resection is becoming an accepted treatment option in this type of tumor, prognostic parameters of this type are of particular interest. By contrast, when metastases are detected in the celiac lymph nodes, it implies that the tumor is unresectable and that palliative treatment is required. Endoscopic ultrasound (EUS)-guided fine-needle aspiration has been found to be the most cost-effective option in this setting. Although autofluorescence endoscopy is being tested as a new technique for endoscopic diagnosis, its value is at present unclear. However, such developments may lead to improved diagnosis in the future, particularly in relation to the initial stages of carcinoma. For the moment, EUS is still the most widely accepted method for early diagnosis and staging. Esophageal squamous-cell carcinoma appears to be commonly associated with head and neck cancer, but the cost-effectiveness of surveillance is a matter of controversy. With regard to Barrett's esophagus and adenocarcinoma, p53 staining in areas of low-grade dysplasia appears to be helpful for predicting progression to high-grade dysplasia. The prevalence of short-segment Barrett's esophagus increases with age, but the length of the segment does not increase with time; the length probably depends on individual conditions, not merely on elapsed time. Helicobacter pylori infection appears to be associated with intestinal metaplasia at the esophagogastric junction. However, the most recent data appear to suggest that this scenario (usually termed "carditis") may be different from intestinal metaplasia in the lower esophagus, related to acid reflux. A follow-up program might be able to detect Barrett's esophagus adenocarcinoma at earlier stages, but only a minority of Barrett's esophagus patients are likely to be detected before neoplasia has developed. Gastric cancer appears to develop in individuals with H. pylori infection, but not in uninfected persons. In addition, those with severe gastric atrophy, corpus-predominant gastritis, and intestinal metaplasia may be at greater risk for gastric cancer. This again raises the question of H. pylori eradication in asymptomatic individuals with infection, and surveillance of patients with severe intestinal metaplasia. The most recent data appear to support the notion that healing of MALT lymphoma depends not only on H. pylori eradication and on the stage of the tumor, but also on individual factors (possibly immunology-related).
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PMID:Diagnosis of esophagogastric tumors. 1251 Feb 24

Many epidemiological studies have shown a strong association between chronic Helicobacter pylori infection and subsequent development of gastric carcinoma in humans. To confirm this link more clearly, it is necessary to use this bacterium in experimental studies to develop gastric carcinoma in suitable experimental animals. Persistent H. pylori infection has recently been achieved in the Japanese Monkeys and Mongolian gerbil models, with results demonstrating that the sequential histopathological changes in the gastric mucosa are closely mimic the gastric mucosal changes caused by H. pylori infection in humans. Gastric mucosa infected with H. pylori exhibited significantly higher gastritis score, reduction in glandular height, increase in the number of Ki-67 positive cells and over expression of p53 protein and p53 gene mutation in the Japanese Monkey Model. In the Mongolian gerbil model, H. pylori infection enhances gastric carcinogenesis in combination with known carcinogens such as MNU and MNNG, and also demonstrated that H. pylori infection alone can result in the development of gastric carcinoma. However, diagnostic criteria of gastric carcinoma in animal models remain in the great discussion. These important results provide a starting point for further studies to clarify the mechanism of gastric carcinogenesis as a result of H. pylori infection and assist the planning of eradication therapy to prevent gastric carcinoma.
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PMID:Helicobacter pylori and gastric carcinoma--from the view point of animal model. 1252 42

Cancers may develop in the background of genomic instability with accumulated mutations. Helicobacter pylori gastritis is characterized by acute foveolitis of the proliferative zone, which is found in any stage of the gastritis as long as the infection persists. Because acute foveolitis targets specifically the proliferative zone of pits, the proliferating epithelial cells are under severe and persistent mutagenic pressure. In H. pylori gastritis, a characteristic morphological change of epithelial cells, the malgun (clear) cell change is frequently present in association with acute foveolitis. Malgun cells have enlarged euchromatic nuclei and abundant cytoplasm. The expression of proliferating cell nuclear antigen and cytokeratin 8 are typically up-regulated in them indicating that they are mitotically and metabolically active. Here, we report evidence for DNA damage and repair in malgun cells. Significant double-strand DNA breaks were shown by the consistent terminal dUTP nick-end labeling in the nuclei of malgun cells. Proteins related to DNA damage and repair, such as Ku, poly(ADP-ribosyl) polymerase, OGG1, and MSH2 were selectively up-regulated in malgun cells. Inducible nitric oxide synthase was also up-regulated. There were occasional bcl2- and p53-expressing cells suggesting that further steps of carcinogenesis took place at the single cell level. Our results suggest that the malgun cell change represents a characteristic morphological sign of cellular genomic damage and repair, and may be implicated in an early stage of carcinogenesis. It is suggested that acute foveolitis of the proliferative zone is a major pathogenetic step of gastric carcinogenesis in H. pylori gastritis.
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PMID:Malgun (clear) cell change in Helicobacter pylori gastritis reflects epithelial genomic damage and repair. 1265 12

H. pylori colonisation of the stomach causes the recruitment of the inflammatory cells by the adherence of the bacteria with the epithelium and the release of factors of virulence either to the contact (oipA or other soluble factors) or in the cell by translocation (CagA). Such contact triggers interleukin 8 expression in the epithelial cell and attracts lymphocytes and monocytes into the chorion. Bacterial lipopolysaccharide and urease support the activation of these inflammatory cells. The lymphocytes produce pro-inflammatory cytokines, which direct the immune response towards the Th1 pathway. The variability of the inflammatory response depends on hereditary factors of the host such as the interleukin 1 genotypes, which determine the level of the pro-inflammatory cytokine expression, and of bacterial factors such as the cag pathogenicity island, the lipopolysaccharide and the vacuolating toxin, vacA. The mucosal inflammation provokes apoptosis and atrophy of the epithelial cells through the effect of pro-inflammatory cytokines and free radicals. Epithelial proliferation is a consequence of excessive apoptosis caused by the infection. It is stimulated by the expression of inducible cyclo-oxygenase and inducible nitric oxide synthase. The development of atrophic gastritis towards cancer is supported by nitric oxide which has a mutagenic effect on DNA and inhibits p53 protein and by the bacterium itself which decreases DNA mismatch repairing activity. The gastritis induced by Helicobacter pylori changes acid secretion according to the prevalent location of the gastritis in the antrum or in the gastric body. Prevalent gastritis in the gastric body causes hypochlorhydria by reducing the release of histamin from ECL cells and inhibiting the parietal cells through the effect of tumor necrosis factor and interleukin 1-beta. Hypochlorhydria is more marked among patients having a pro-inflammatory genotype for interleukin 1-beta and those infected by bacteria with virulence factors. In the event of antrum predominant gastritis, the pro-inflammatory cytokines cause a reduction of somatostatin and gastrin releases from the D and the G cells, respectively. The result of all is increased maximal acid output and the meal-stimulated acid secretion.
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PMID:[What are the gastric modifications induced by acute and chronic Helicobacter pylori infection?]. 1270 Apr 95


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