Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024623 (gastric cancer)
 36,219 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

MUC1 mucin is an anti-adhesion molecule expressed in a wide variety of tumors. To examine whether MUC1 mucin is involved in tumor invasion, we have prepared MUC1 transfectants using the human gastric cancer cell line MKN74 and performed an in vivo tumor assay by transplanting these into nude mice. Tumor weight at 71 days after s.c. injection of transfectants was measured, showing that the in vivo growth of MUC1 transfectants was increased compared to that of mock transfectants. Furthermore, MUC1-transfectant tumors invaded into the muscle layer, whereas mock-transfectant tumors did not. In vitro invasion, adhesion to extracellular matrix components and phagokinetic track motility were then evaluated to analyze the mechanisms for the in vivo invasiveness of the transfectants. MUC1 transfectants exhibited an increased in vitro invasiveness, decreased binding to laminin, fibronectin, type I collogen and type IV collagen and increased motility. These effects of MUC1 mucin over-expression in MKN74 cells were abolished by the treatment of transfectants with an inhibitor of O-glycan biosynthesis, benzyl-alpha-GalNAc. Our data suggest that MUC1 mucin could be related to the increased invasive ability of MKN74 cells, whereas O-glycan might play an essential role.
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PMID:Increased invasiveness of MUC1 and cDNA-transfected human gastric cancer MKN74 cells. 957 75

Extracellular matrix proteins and proteins involved in epithelial adhesion are essential for maintenance of tissue structure. Helicobacter pylori is the major aetiological agent in peptic ulcer disease and has been shown to increase gastric cancer risk up to ninefold. In this study, changes induced by H pylori on the expression of extracellular matrix proteins (collagen IV, fibronectin, and laminin) as well as two essential proteins for cell-basement and cell-cell adhesion (alpha 6-integrin and E-cadherin) were assessed. Immunohistochemistry was performed in antral biopsy sections obtained from infected and non-infected patients, and light microscopy was used to determine the distribution and intensity of specific staining. The results showed that the infection was significantly associated with downregulation of E-cadherin, an essential protein for maintenance of solid tissues and differentiation, but did not induce changes in the expression of alpha 6-integrin or the extracellular matrix proteins.
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PMID:H pylori infection is associated with downregulation of E-cadherin, a molecule involved in epithelial cell adhesion and proliferation control. 970 15

To determine if peritoneal collagen type IV levels could serve as a parameter for predicting metastasis and the subsequent course of disease, the concentration of collagen IV in the peritoneal fluid of 85 patients with adenocarcinoma of the gastrointestinal tract, including 50 with gastric cancer and 35 with colorectal cancer, was measured radioimmunologically. The peritoneal collagen type IV levels were elevated in 13 (26%) of the patients with gastric cancer, in 8 (23%) of those with colorectal cancer, and in none of the control subjects. The mean concentration of collagen type IV in tumors characterized by peritoneal dissemination was significantly higher than that in those without metastasis; however, there were no significant differences in the collagen type IV levels between tumors with and those without liver metastasis, or between those with and those without lymph node metastasis. There was a significant correlation between the peritoneal collagen type IV level and survival time in patients with clinically evident peritoneal dissemination. A positive correlation was also found between collagen type IV and carcinoembryonic antigen levels. In conclusion, the levels of peritoneal collagen type IV provide evidence of peritoneal dissemination, and can aid in the prediction of life expectancy in patients with adenocarcinomas of the gastrointestinal tract.
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PMID:Peritoneal collagen type IV concentration in adenocarcinoma of the gastrointestinal tract and its relationship to histological differentiation, metastasis, and survival. 971 96

The actual mechanisms by which carcinoma cells metastasize to lymph nodes are still unclear, and there is a need to establish in vivo experimental models suitable for the investigation of lymph node metastasis. For the purpose, we established a highly lymph node-metastasizing line, designated AZL5G, derived from a human gastric cancer cell line, AZ521, which had low capacity for lymph node metastasis. AZL5G cells transplanted orthotopically in the nude mouse stomach metastasize predominantly to the regional lymph nodes, showing little potential for hematogenous metastasis. AZL5G tumors developing in the stomach and regional lymph nodes showed poorly differentiated adenocarcinoma with medullary growth, and their histologic appearance strongly resembled that of parental AZ521. The growth activities in vitro of low-metastatic AZ521 and high-metastatic AZL5G were almost the same, but the tumorigenicity in vivo of AZL5G was significantly higher than that of AZ521. AZL5G cells also showed clearly higher abilities of cell locomotion and adhesion to type IV collagen and fibronectin in vitro as compared with AZ521 cells. Flow cytometric analysis demonstrated that the expression of integrin beta1 subfamily except for alpha6 integrin was generally increased in AZL5G cells than in AZ521 cells. Especially, the expression of alpha1 and alpha2 integrins in AZL5G cells was clearly higher than in AZ521, while alpha(v)beta3 integrin, E-cadherin, ICAM-1 and CD44H were not expressed by either cell line. The cell adhesion blocking assay showed that DGEA-containing peptide, which is composed of alpha2 integrin recognition sequence, significantly reduced the adhesiveness of AZL5G cells to type IV collagen as well as to type I collagen and laminin. Furthermore, the administration of anti-alpha2 integrin mAb or DGEA peptide in AZL5G-transplanted nude mice produced a significant reduction in the number of lymph node metastases. These data suggest that the up-regulation of alpha2 integrin expression by gastric cancer cells may play a critical role in the process of lymph node metastasis through the increased adhesiveness to type IV collagen. In conclusion, we established a gastric cancer cell line, AZL5G, with a highly metastatic potential to lymph nodes. This well-characterized line and its in vivo experimental model should be useful for investigation of the mechanisms of lymph node metastasis and for establishment of a new therapeutic approach for human gastric cancer.
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PMID:Establishment and characterization of a human gastric carcinoma cell line that is highly metastatic to lymph nodes. 1084 Sep 45

In the present study, the role of integrin alpha2/beta1 in peritoneal dissemination of gastric cancer was investigated using an in vivo xenograft model for the highly metastatic MKN-45-P gastric cancer cells. Metastatic ability of MKN-45-P cells was significantly associated with the simultaneous expression of integrin alpha2 and alpha3 subunits. In an in vitro adhesion assay, neutralizing antibody for integrin alpha2 or beta1 subunit inhibited the adhesion of MKN-45-P cells to collagen type I and type IV. Moreover, the injection of anti-beta1 monoclonal antibody reduced the number of cancer cells on the peritoneum in nude mice that had been inoculated with MKN-45-P cells. These results suggest that integrin alpha2/beta1 represents a candidate target molecule available for the prevention of gastric cancer peritoneal dissemination.
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PMID:Significance of integrin alpha2/beta1 in peritoneal dissemination of a human gastric cancer xenograft model. 1125 Nov 78

The receptor for advanced glycation end-products (RAGE) is a newly recognized factor regulating cancer cell invasion and metastasis. This study investigated the expression of RAGE in gastric carcinomas and its association with invasion and metastasis. Of eight gastric cancer cell lines examined, seven constitutively expressed RAGE messenger ribonucleic acid (mRNA), MKN45 being the exception. RAGE protein expression of MKN28 cells treated with RAGE antisense S-oligodeoxynucleotide was nine times less than that of sense S-oligodeoxynucleotide-treated cells. Growth of cells under RAGE antisense S-oligodeoxynucleotide treatment was not different from that seen under sense S-oligodeoxynucleotide treatment in MKN28 (a cell line producing high levels of RAGE) and MKN45 (a non-RAGE-expressing cell line). RAGE antisense S-oligodeoxynucleotide treatment suppressed the invasive activity of RAGE-positive MKN28 cells, as estimated by in vitro invasion assay. The number of MKN28 cells invading the type IV collagen-coated membrane under RAGE antisense S-oligodeoxynucleotide treatment was significantly lower than under RAGE sense S-oligodeoxynucleotide treatment (p<0.0001). In contrast, antisense and sense S-oligodeoxynucleotide-treated RAGE-negative MKN45 cells showed no difference. A wound-healing assay showed that no RAGE antisense S-oligodeoxynucleotide-treated MKN28 cells migrated into the scraped area, whereas sense S-oligodeoxynucleotide-treated cells showed many budding nests in the scraped area. Immunohistochemistry of gastric carcinoma tissue showed that 62 (65%) of the 96 cases examined were RAGE-positive and that poorly differentiated adenocarcinomas preferentially expressed RAGE protein (38/42, 90%) (p<0.0001). Strong RAGE immunoreactivity was also correlated with depth of invasion and lymph node metastasis (p<0.0001). RAGE-positive cancer cells tended to be distributed at the invasive front of primary tumours and were detected in all metastatic foci in lymph nodes. In contrast, a major RAGE ligand, amphoterin, was expressed in 82 (85%) of the 96 cases, regardless of histological type and disease progression. RAGE expression appears to be closely associated with invasion and metastasis in gastric cancer.
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PMID:Expression of receptors for advanced glycation end-products (RAGE) is closely associated with the invasive and metastatic activity of gastric cancer. 1179 67

We investigated the biologic behavior of gastric phenotype carcinoma of the stomach, especially in association with degradation of the extracellular matrix. One hundred fourteen lesions of intramucosal gastric carcinoma (IMGC) of differentiated type were studied. IMGCs were classified into 4 phenotypic categories--complete intestinal type (C type), incomplete intestinal type (I type), gastric type (G type), and unclassified type--through a combination of the expression of CD10, MUC2, HGM, and Con A. The expression of MMP-2, MMP-9, TIMP-2, and type IV collagen was investigated by immunohistochemical staining. The incidence of C-type IMGC, I-type IMGC, and G-type IMGC was 7.9%, 55.3%, and 36.8%, respectively. The incidence of positive MMP-9 expression in G-type IMGCs (57%) was significantly higher than that in C-type IMGCs (11%) or I-type IMGCs (35%) (P < .01). There was no significant correlation between phenotypes and expression of MMP-2, TIMP-2, or type IV collagen. There was a reverse correlation between the expression of type IV collagen and the expression of type IV collagenase (P < .001). In conclusion, gastric phenotype carcinomas have been shown to be highly invasive and metastatic, However, although they can potentially degrade the extracellular matrix via overexpression of MMPs compared with intestinal phenotype carcinoma, our data show no statistically significant separation of subtypes of intramucosal gastric cancer based on gross classification, histologic type, lymphatic or venous invasion, or lymph node metastases.
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PMID:Relationship between biologic behavior and phenotypic expression in intramucosal gastric carcinomas. 1182 76

Although several hypotheses have been proposed explaining the mechanisms of the immune-privileged status of malignant tumors, the exact pathway is yet to be explored. Tumor stroma plays a vital role in the prognosis of cancer patients; however, the immunomodulatory impact of gastric cancer stroma has not been reported. We have evaluated the amount of stromal collagen and its impact on the infiltration of immune-competent cells into the tumor cell nest in gastric carcinoma. Tissue specimens from 84 advanced gastric carcinoma patients who had undergone a curative resection were evaluated for host immune status (CD8+ T cells), tumor stromal reaction (AZAN staining), tumor Fas ligand expression and incidence of tumor cell apoptosis (by TUNEL). The number of apoptotic tumor cells (apoptotic index [AI]) increased proportionally with an increase in the number of CD8+ T cells within the cancer cell nest (nest CD8) (p = 0.0001). Nest CD8 was inversely correlated with the amount of stromal collagen (p < 0.0001). Nest CD8 and AI became independent predictors of patient survival (p = 0.0023 and p = 0.044, respectively) in Cox's multivariate analysis. The amount of stromal collagen was found to be a significant predictor of disease relapse in univariate analysis (p = 0.0010) but not in multivariate analysis (p = 0.4729). In conclusion, increased nest CD8 produced a survival advantage by inducing tumor cell apoptosis in gastric carcinoma patients. Increased tumor stromal collagen worked as a barrier for CD8+ T-cell infiltration and might be one of the mechanisms of tumor escape from the host immune attack.
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PMID:Role of stromal collagen in immunomodulation and prognosis of advanced gastric carcinoma. 1185 52

Two human breast cancer cell lines of differing invasive and metastatic potential, MDA-MB-435 and MCF7, were examined using subtractive suppression hybridization in a search for any genes associated with metastasis. Of the 17 cDNAs identified as being differentially expressed genes, it was determined that syntenin was overexpressed in metastatic MDA-MB-435 cells. Expression analysis showed that the expression level of syntenin was well correlated with invasive and metastatic potential in various human breast and gastric cancer cell lines. Moreover, gastric tumor tissues exhibited a much higher syntenin mRNA expression than their normal counterparts. Syntenin-transfected MCF7 cells migrated more actively, and showed an increased invasion rate relative to vector-transfectants or parental MCF7 in vitro, without evidencing any effect on the adhesion to fibronectin, type I collagen and laminin. Similarly, the forced expression of syntenin to human gastric cancer cell line Az521 increased its migratory and invasive potential in vitro. Syntenin-expressing MCF7 cells were associated with the appearance of numerous cell surface extensions and with pseudopodia formation on collagen I, suggesting that syntenin may be involved in the signaling cascade to actin-reorganization. Mutation study suggested that PDZ2 domain of syntenin could be an essential role in its stimulatory effect on the cell migration. This is the first demonstration that syntenin, a PDZ motif-containing protein, can be overexpressed during the metastatic progression of human breast and gastric cancer cells and that it can function as a metastasis-inducing gene.
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PMID:Syntenin is overexpressed and promotes cell migration in metastatic human breast and gastric cancer cell lines. 1203 64

The risk of gastric cancer increases with the severity of gastric mucosal atrophy. Atrophy is a 'loss of properly specialized glands'. These glands may be substituted by metaplastic cells and by interstitial fibrosis, or displaced by an inflammatory infiltrate. Agreement among pathologists for the diagnosis of atrophy is poor (kappacoefficient < 0.4), probably because inflammatory infiltrate can confound the identification of gland loss. The aim of this study was to evaluate interstitial fibrosis by image analysis, and thereby overcoming the confounding effect of the inflammatory infiltrate. Gastric biopsies of 40 controls (20 children and 20 adults) and 111 patients with chronic atrophic gastritis were examined. Patients underwent another biopsy a year later. Gastric sections were examined by conventional histology (updated Sydney system) and image analysis to detect collagen and non-collagen fibres. There were no significant intra- or inter-operator differences in the evaluation by image analysis of fibre content in either controls or patients. In both controls and patients, the mean percentage of collagen fibres was lower in the gastric body (9%) than in the antrum (10%). In the antrum it was 14%, 17% and 20% in patients with mild, moderate and severe atrophy, respectively. A year later, histology showed that the grade of atrophy had decreased in 42%, probably due to the regression of inflammation, and increased in 10% of cases, but interstitial fibrosis (expressed as collagen fibre content) was practically unchanged. The use of image analysis of gastric biopsies appears to be a reliable method with which to measure interstitial fibrosis, even in the presence of an inflammatory infiltrate. This study highlights the difference between 'real gastric atrophy', where glands are replaced by collagen fibres, and 'apparent gastric atrophy', where glands are displaced by an inflammatory infiltrate.
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PMID:Diagnosis of chronic atrophic gastritis by morphometric image analysis. A new method to overcome the confounding effect of the inflammatory infiltrate. 1221 62


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