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Query: UMLS:C0024623 (gastric cancer)
 36,219 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Helicobacter pylori infection is a risk factor for gastric cancer. How the bacterium contributes to this process is still unclear. We present a new Wistar rat model that was used to evaluate the effect of H. pylori on early preneoplastic events as judged from epithelial cell turnover and histopathological changes. One hundred and four rats were colonized with H. pylori and exposed MNNG (N-methyl-N'-nitro-N'-nitrosoguanidine) and/or taurocholic acid. Inflammation, goblet cell-like metaplasia, atrophy, dysplasia, and adenocarcinoma were scored in a blinded manner. Apoptotic cells were counted after staining with terminal uridine deoxynucleotidyl nick end labeling, and epithelial cell proliferation was determined by means of the Ki-67 labeling index. No early tumor enhancement with H. pylori could be found in ordinary histology. However, H. pylori significantly enhanced the epithelial cell proliferation compared with the control group, and the combination with taurocholic acid appeared to have a synergistic effect. MNNG significantly increased the normal gastric epithelial apoptosis. This increase was reduced in antral mucosa with H. pylori infection. The findings suggest that H. pylori, especially when combined with bile. has an influence on cell kinetics, contributing to the development of gastric cancer. The reduced apoptosis of MNNG also observed in infected animals indicates a dual function of H. pylori.
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PMID:Helicobacter pylori, N-methyl-N'-nitro-N'-nitrosoguanidine, and bile modulate gastric cell kinetics in experimental cancer. 1176 86

AIM:To evaluate the relationship between the expression of Ki-67 antigen and the pathobiological behaviours of gastric cancers especially their distant metastases.METHODS:Fifty-six specimens of gastric cancer routinely fixed in formalin and embedded in paraffin (FFEP) were studied by immunohistochemical method.RESULTS: Expression of Ki-67 antigen was significantly related to the distant metastases to liver, ovary and adrenal gland (P < 0.01), but not related to the histological type, growth pattern, depth of invasion, histological differentiation and the metastases to local lymph nodes (P > 0.05).Furthermore, the Ki-67 antigen expression was significantly related to the DNA aneuploidy pattern, which is closely related to poor prognosis (P < 0.05).CONCLUSION:Overexpression of Ki-67 can be used as an objectiv marker of the proliferative activity for predicting prognosis of gastric cancer and metastatic potential to distant organs.
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PMID:Relationship between DNA ploidy,expression of ki-67 antigen and gastric cancer metastasis. 1181 73

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.
Gastric Cancer 2000 Dec 27
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

Matrilysin is known to play an important role in tumor invasion, but it is not known yet whether there is a direct relationship between matrilysin expression and cell proliferation. Therefore, we compared expression of matrilysin with expression of Ki-67, a marker of cell proliferation, at different tumor areas in 130 advanced gastric carcinomas. Both matrilysin and Ki-67 were distributed heterogeneously in tumor tissue. Matrilysin frequently was expressed at the invasive front, whereas Ki-67-positive cells frequently were located both at the tumor surface and in central tumor cell nests. The patterns of gastric cancer cell invasion into the surrounding tissues are described as alpha-infiltration, beta-infiltration, and gamma-infiltration, respectively, according to the guidelines of the Japanese Research Society for Gastric Cancer Study. The mean matrilysin labeling index (LI) of gamma-infiltration tumors at the invasive front was significantly greater than that of alpha- and beta-infiltration tumors (P =.01). In contrast to the matrilysin LI, the mean Ki-67 LI of gamma-infiltration tumors was significantly lower than that of alpha- and beta-infiltration tumors (P =.02). Moreover, Ki-67 antigen was absent in matrilysin-positive tumor cells and vice versa. We concluded that matrilysin expression was related inversely with proliferative activity of tumor cells and that matrilysin expression could possibly serve as a useful marker of tumor invasion.
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PMID:Inverse relationship between matrilysin expression and proliferative activity of cells in advanced gastric carcinoma. 1219 26

CDX2, a transcriptional factor expressed in the intestine, is implicated in the development and maintenance of the intestinal mucosa. Recent studies have demonstrated that CDX2 is expressed in the intestinal metaplasia of the stomach and intestinal-type gastric cancer, while it is not expressed in the normal gastric mucosa. To investigate the role of CDX2 in gastric cancer, we determined CDX2 expression and cell proliferation rate in various types of gastric cancer tissues by immunostaining. Surgically dissected gastric cancer tissues were collected from 40 patients. Consistent with previous reports, CDX2 was expressed in most gastric mucosa samples with intestinal metaplasia (89%, 16/18), although it was not found in the adjacent normal mucosa. CDX2 expression was also detected in 64% (18/28) of intestinal-type gastric cancer cases, whereas it was not observed in the diffuse-type gastric cancer (0/12). Moreover, the CDX2-positive gastric cancer samples showed significantly lower index for Ki-67 immunostaining, indicating reduced cell proliferation rates than in the CDX2-negative samples. Importantly, multivariate analysis for the overall survival rate revealed that the CDX2-positive gastric cancer patients survived significantly longer than the CDX2-negative patients. Even among the intestinal-type gastric cancer cases, the CDX2-positive group showed a lower Ki-67 index and longer postoperative survival than the CDX2-negative group. These results collectively indicate that CDX2 expression in gastric cancer tissues can be a novel prognostic marker for patient survival.
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PMID:CDX2 expression in the stomach with intestinal metaplasia and intestinal-type cancer: Prognostic implications. 1223 15

We investigated the effect of expression of survivin, an apoptosis inhibiting protein, on cellular proliferation and apoptosis in gastric cancer and assessed its relation to the pathological characteristics of gastric cancer. Resected gastric cancer specimens from 42 patients (intestinal type; 21 cases and diffuse type; 21 cases) were evaluated. There were no significant differences in the clinicopathologic factors between the two groups. Survivin mRNA expression was measured using real-time reverse transcription-polymerase chain reaction, and survivin protein expression was evaluated by immunohistochemical staining. The Ki-67 index was adopted for cell proliferation scoring, and the ss-DNA positive rate as an apoptotic index. The survivin mRNA expression inversely correlated with the apoptotic index (p<0.05). Survivin mRNA expression (p<0.001) and survivin protein expression (p<0.001) were significantly higher in the diffuse type than the intestinal type. In conclusion, gastric cancer avoids cellular death by survivin expression and this tendency was more conspicuous in diffuse type gastric cancer.
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PMID:Effect of survivin on cell proliferation and apoptosis in gastric cancer. 1237 22

Gastric cancer, characterized by poor prognosis, remains a global health problem. Thus, it is important to describe the biological factors which can affect the prognosis in this disorder. The aim of our study was the determination of the relationship between apoptotic index (AI) and other clinicopathological features (Ki67 labeling index = Ki-67 LI, neovascularity defined as CD-34 immunoreactivity - intratumoral microvessel density = IMVD, p53 immunopositivity, grade of malignancy, histological type, depth of tumour invasion, lymph node status) in 49 cases of gastric carcinoma. Recognition of apoptotic cells was performed applying the terminal deoxynucleotydil transferase mediated dUTP-digoxigenin nick end labeling technique (TUNEL). Among the tumours, 30 were intestinal type and 19 were diffuse type, including 17 cases of well and moderately differentiated tumours (G1 and G2) and 32 poorly differentiated tumours (G3). Apoptotic index was determined in all the examined tumours, and the mean value of AI was 5.8% +/- 4.7%. We found a significant relationship between AI, grade of malignancy and Ki-67 LI. Significantly higher AI -8.1% +/- 5.7% was observed in G1-G2 tumours in comparison to 4.7 +/- 3.8% (p<0.05) in G3 tumours. In tumours with high proliferative potential (above mean value of Ki-67 LI -29.77% +/- 24.9%) we observed higher apoptotic index, mean value 7.9% +/- 5.7%, and in tumours with low proliferation (Ki-67 LI below 29%) mean AI was 4.4% +/- 3.7% (p<0.05). The p53 positive immunoreactivity was found in 30 out of 49 cases (mean AI = 6.75% +/- 4.8%). No apparent correlation between AI, histopathological type of gastric cancer, lymph node status and p-53 and CD-34 immunoreactivity was found.
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PMID:Extent of spontaneous apoptosis in gastric cancer: relation to proliferative index, p53 expression, CD 34 expression and histopathological features. 1238 80

The mitotic spindle assembly checkpoint modulates the timing of anaphase initiation in response to improper alignment of chromosomes at the metaphase plate. The BUB gene family encodes proteins which are part of a large multi-protein kinetochore complex and which are believed to be key components of the checkpoint regulatory pathway. Failure of this surveillance system can lead to genomic instability and could be responsible for the increased incidence of aneuploidy in gastric cancer. Since mutations of BUB genes have not been identified in gastric cancer to date, altered BUB expression levels may significantly impair mitotic checkpoint function. To explore this possibility, the expression levels of BUB1, BUBR1, and BUB3 were determined in 43 gastric carcinomas and corresponding normal gastric mucosa by reverse transcription-polymerase chain reaction (RT-PCR). Gene expression levels were compared with histopathological parameters and DNA ploidy, as well as with proliferative activity, measured by Ki-67 mRNA expression. To the authors' knowledge, this is the first study to investigate the expression levels of mitotic checkpoint genes together with DNA ploidy in gastric cancer. BUB1 was overexpressed in 84%, BUBR1 in 68%, and BUB3 in 79% of gastric cancers. This study also revealed that all three genes were simultaneously overexpressed in 61% of the tumours and that there was a statistically significant positive correlation between overexpression of BUB1, BUBR1 or BUB3 and Ki-67 expression (p < 0.001). Eighty-one per cent of the tumours were classified as aneuploid. However, no correlation was found between ploidy and BUB transcript expression levels. These results suggest that inactivation of the mitotic checkpoint genes BUB1, BUBR1, and BUB3 by epigenetic silencing does not seem to play a role in gastric carcinogenesis. The strong correlation of BUB expression level and tumour cell proliferation suggests that BUB overexpression is a proliferation-dependent phenomenon in gastric cancer. However, overexpression due to lack of normal BUB protein function or due to a yet unknown additional BUB function has to be considered.
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PMID:Overexpression of the mitotic checkpoint genes BUB1, BUBR1, and BUB3 in gastric cancer--association with tumour cell proliferation. 1269 36

We describe a hitherto unknown lesion of gastric chief cell proliferation mimicking structurally mucosal gastric cancer. The unremarkable cytology of the cells, their very low Ki-67 index, the inclusion of occasional parietal cells and especially ultrastructural evidence of chief cell differentiation proved helpful in the differentiation from early gastric cancer. The exact classification of the alteration remains unresolved. The presence of microcysts suggests that the lesion is a variant of fundic gland polyp formation.
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PMID:Chief cell proliferation of the gastric mucosa mimicking early gastric cancer: an unusual variant of fundic gland polyp. 1269 65


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