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)

Gastrectomy has been implicated in cholelithiasis. Impaired gallbladder motor function after the operation has been thought to be one of the major mechanisms. This study was undertaken to determine the effect of gastrectomy on release of cholecystokinin and contractile motility of gallbladder in five patients with early gastric cancer. After 14 hours fast, the gallbladder area was estimated by ultrasonography every 10 minutes for 120 minutes both before and after oral administration of 200 ml of Clinimeal. Blood samples were collected simultaneously via a peripheral vessel for measurement of plasma CCK levels by radioimmunoassay. Gallbladder contraction correlated well with the elevation of plasma CCK levels indicating that CCK might be one of the major factors governing gallbladder contraction both in pre- and post-gastrectomized conditions. Compared with preoperative cases, the postgastrectomized patients showed a significantly exaggerated postprandial response of CCK release in the initial 60 minutes, however, their gallbladder, responding to rapid reduction of plasma CCK levels, refilled significantly earlier. Postprandial rapid gastric emptying was thought to be related to the exaggerated postprandial CCK release, and the early refilling of the gallbladder might be attributed to the indefinite vagal or sympathetic denervation that might occurs during the necessarily wide lymph node dissections for gastric cancer operations.
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PMID:[The effect of gastrectomy on cholecystokinin (CCK) release and gallbladder contraction in patients with early gastric cancer--preliminary report]. 277 68

An isoform cDNA of CCK-B/gastrin receptor was isolated from human stomach. This cDNA differed from initially cloned cDNA only in the 5'-end region and encoded a truncated isoform (delta CCK-B) in which the putative N-terminal extracellular domain of the CCK-B/gastrin receptor was completely lost. Isolation of genomic CCK-B/gastrin receptor DNA revealed that this transcript is generated by alternative usage of a novel exon, termed exon 1b. Human stomach expressed both transcripts of delta CCK-B and entire CCK-B/gastrin receptor (CCK-BR), whereas human stomach cancer cell line AGS exclusively expressed delta CCK-B transcripts. Transfection of COS-7 with delta CCK-B cDNA led to the appearance of binding sites for 125I-CCK-8. Its ligand selectivity was different from that of CCK-BR. These results suggest the molecular diversity in CCK-B/gastrin receptor subtypes.
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PMID:A truncated isoform of human CCK-B/gastrin receptor generated by alternative usage of a novel exon. 788 34

Exogenous gastrin exerted a trophic effect on the human gastric adenocarcinoma cell line AGS with a maximum stimulation at 100 pM. The CCK/gastrin receptor antagonists proglumide and loxiglumide dose-dependently inhibited spontaneous growth of AGS gastric cancer cells with half maximal inhibition at 8 mM and 200 microM, respectively. This growth inhibition could not be reversed by coincubation with gastrin. In control experiments with murine 3T3 fibroblasts gastrin had no growth-promoting effect. Proglumide and loxiglumide, however, exerted the same growth inhibition on 3T3 cells as they did on gastrin-responsive AGS tumor cells, suggesting a gastrin receptor independent mode of action. L 365, 260 had no effect on the spontaneous growth of AGS tumor cells, but abolished growth stimulation by exogenous gastrin in a dose-dependent manner. These results suggest that only the high-affinity gastrin receptor antagonist L 365, 260 acts by a specific, i.e. selective, reversible, and competitive mode of action. In contrast, the low affinity CCK/gastrin receptor antagonists proglumide and loxiglumide obviously have an irreversible and non-competitive mode of action with respect to growth inhibition of AGS gastric cancer cells, which is not mediated by gastrin receptors.
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PMID:Differential mode of action of high- and low-affinity CCK/gastrin receptor antagonists in growth inhibition of gastrin--responsive human gastric adenocarcinoma cells in vitro. 831 2

Several problems are associated with gastric resection, including the dumping syndrome, reflux esophagitis, and malabsorption. A better understanding of the pathophysiological changes will shed light on new and improved therapy. Serum levels of seven circulating gastrointestinal hormones following a standardized solid meal and a brief score of symptoms were evaluated in 10 patients after partial distal gastrectomy and 12 patients after total gastrectomy, both groups reconstructed by Billroth II anastomosis, and 9 age-matched healthy controls. Patients underwent resection for gastric cancer and were studied 45 +/- 10 months after surgery. At the time of study, the patients had adapted well to surgery and no longer exhibited the severe symptoms of dumping seen immediately post-operatively. In contrast, the total gastrectomy patients exhibited the symptoms of reflux esophagitis. The gastrointestinal hormone changes could be divided into three patterns; obtunded responses (gastrin, PP), normal release (motilin, GIP) and increased secretion (CCK, neurotensin, PYY). In these, the early reaction of neurotensin correlated with the scores of late dumping syndrome and reflux esophagitis. In the literature, many gastrointestinal hormones have been shown to respond as an enhancement rather than adaptation. In other gastrointestinal hormones, secretin belonged to the obtunded type and enteroglucagon were classified in the increased type. However, pathophysiological significance of these hormonal changes remained uncertain. The late adaptive changes in gastrointestinal hormone secretion may help to compensate for loss of gastric motor function which accompanies gastric resection. On the other hand, these hormonal changes may exacerbate the esophageal reflux following gastrectomy.
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PMID:Gastrointestinal hormone in dumping syndrome and reflux esophagitis after gastric surgery. 940 15

In this study we identified and characterized the receptor related to the modulation of growth of human gastric cancer by gastrin. By performing receptor binding assays on human AGS gastric cancer cells with the selective CCK-B/gastrin receptor antagonist [3H]L-365,260, specific and saturable binding were determined. Binding was dependent on protein concentration, time, temperature, and the presence of protease inhibitors, and was located in the membrane fraction. Gastrin, as well as CCK, stimulated gastric cancer cell growth in a receptor-mediated fashion at a concentration consistent with the binding affinity. Receptor gene expression for the CCK-B/gastrin receptor, but not for the CCK-A receptor, was found by reverse transcription polymerase chain reaction. Receptor binding assays as well as transcriptional and growth studies provide evidence that gastrin-stimulated growth of human gastric cancer is mediated by CCK-B/gastrin-like receptors.
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PMID:Characterization of CCK-B/gastrin-like receptors in human gastric carcinoma. 945 69

Numerous epidemiological studies demonstrated the association between Helicobacter pylori (H. pylori) infection and gastric cancer but the mechanism of the involvement of H. pylori in gastric cancerogenesis remains virtually unknown. This study was designed to determine the seropositivity of H. pylori and cytotoxin associated gene A (CagA), serum gastrin and gastric lumen gastrin levels under basal conditions and following stimulation with histamine in gastric cancer patients and controls. 100 gastric cancer patients aging from 21 to 60 years and 300 gender- and age-adjusted controls hospitalized with non-ulcer dyspepsia (NUD) entered this study. 13C-Urea Breath Test (UBT), serum immunoglobulin (IgG) antibodies to H. pylori and CagA were used to assess the H. pylori infection and serum levels of IL-1beta, IL-8 and TNFalpha were measured by enzyme-linked immunosorbent assay (ELISA) to evaluate the degree of gastric inflammation by H. pylori . Gastrin-17 mRNA and gastrin receptors (CCK(B)) mRNA expression in gastric mucosal samples taken by biopsy from the macroscopically intact fundic and antral mucosa as well as from the gastric tumor was determined using RT-PCR. The overall H. pylori seropositivity in gastric cancer patients at age 21-60 years was about 92%, compared, respectively, to 68%, in controls. A summary odds ratio (OR) for gastric cancer in H. pylori infected patients was about 5.0 . The H. pylori CagA seropositivity in gastric cancer patients was about 58.5% compared to 32.4% in controls, giving the summary OR for gastric cancer in CagA positive patients about 8.0. The prevalence of H. pylori- and H. pylori CagA-seropositivity was significantly higher in cancers than in controls, irrespective of the histology of gastric tumor (intestinal, diffuse or mixed type). Median IL-1beta and IL-8 reached significantly higher values in gastric cancer patients (9.31 and 30.8 pg/ml) than in controls (0.21 and 3.12, respectively). In contrast, median serum gastrin in cancers (as total group) was several folds higher (62.6 pM) than in controls (19.3 pM). Also median luminal gastrin concentration in gastric cancer patients was many folds higher (310 pM) than in controls (20 pM). This study shows for the first time that cancer patients are capable of releasing large amounts of gastrin into the gastric lumen to increase luminal hormone concentration to the level that was recently reported to stimulate the growth of H. pylori. There was no any correlation between plasma gastrin levels and gastric luminal concentration of gastrin suggesting that: 1) luminal gastrin originates from different source than plasma hormone, most probably from the cancer cells, 2) cancer cells are capable of expressing gastrin and releasing it mainly into the gastric juice and 3) the gastric cancer cells are equipped with gastrin-specific (CCK(B)) receptor so they exhibit the self-growth promoting activity in autocrine fashion. This notion is supported by direct detection of gastrin mRNA and gastrin receptor (CCK(B)-receptors) mRNA using RT-PCR in cancer tissue. To our knowledge this is the first study showing an important role of gastrin as self-stimulant of cancer cells in patients infected with H. pylori. Basal and histamine maximally stimulated acid outputs were significantly lower in gastric cancer patients than in controls despite of enhanced gastrin release, particularly in cancer patients and this might reflect the mucosal inflammatory changes (increased serum levels of proinflammtory interleukins - IL-1beta and IL-8), that are known to increase gastrin release. We conclude that: 1) H. pylori infected patients, particularly those showing CagA-seropositivity, are at greatly increased risk of development of gastric cancer, 2) H. pylori-infected cancer patients produce significantly more IL-1beta and IL-8 that might reflect an H. (ABSTRACT TRUNCATED)
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PMID:Role of gastrin in gastric cancerogenesis in Helicobacter pylori infected humans. 1069 65

The effect of gastrin on stimulating tumour proliferation has been evaluated on human pancreas cancer cells in culture and in tumours transplanted to nude mice. The presence of CCK-B/gastrin-like receptor responsible for that effect of gastrin has been proved in colonic (WiDr, HT-29, YAMC) and pancreatic (PANC-1, BON) cell lines. The aim of our study was to examine the stimulating effect of gastrin and pentagastrin on the growth of human gastric adenocarcinoma cell line. The human gastric adenocarcinoma cell line (AGS, CRL-1739) was purchased from ATCC (Rockville, MA, USA). Gastrin-17 was purchased from Sigma-Aldrich (Budapest, Hungary), pentagastrin was from Zeneca Limited (Macclasfield, UK). The cells were incubated in DMEM containing 10% FCS on 96-well culturing plate with 10(4) cells/well starting cell number at 37 degrees C with 5% CO2. The proliferation rates were detected: by the measurements of the metabolically active cells with Owen's reagent and the determination of protein content, and by cell counting in a haemocytometer at several incubation times. As a result, we detected similar proliferation rates using gastrin-17 or pentagastrin in the incubation medium. The stimulating effect of gastrin/pentagastrin on cell line proliferation was in correlation with its concentration. Our results proved that pentagastrin is a 10 times less effective stimulator of proliferation of gastric cancer than gastrin-17, and that AGS human adenocarcinoma cell line might be CCK receptor positive.
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PMID:Gastrin and pentagastrin enhance the tumour proliferation of human stable cultured gastric adenocarcinoma cells. 1076 93

Recently, we cloned a novel serine/threonine kinase termed protein kinase D2 (PKD2). PKD2 can be activated by phorbol esters both in vivo and in vitro but also by gastrin via the cholecystokinin/CCK(B) receptor in human gastric cancer cells stably transfected with the CCK(B)/gastrin receptor (AGS-B cells). Here we identify the mechanisms of gastrin-induced PKD2 activation in AGS-B cells. PKD2 phosphorylation in response to gastrin was rapid, reaching a maximum after 10 min of incubation. Our data demonstrate that gastrin-stimulated PKD2 activation involves a heterotrimeric G alpha(q) protein as well as the activation of phospholipase C. Furthermore, we show that PKD2 can be activated by classical and novel members of the protein kinase C (PKC) family such as PKC alpha, PKC epsilon, and PKC eta. These PKCs are activated by gastrin in AGS-B cells. Thus, PKD2 is likely to be a novel downstream target of specific PKCs upon the stimulation of AGS-B cells with gastrin. Our data suggest a two-step mechanism of activation of PKD2 via endogenously produced diacylglycerol and the activation of PKCs.
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PMID:Mechanism of activation of protein kinase D2(PKD2) by the CCK(B)/gastrin receptor. 1205 27

Hypergastrinemia in INS-GAS mice leads to accelerated carcinogenesis of the stomach, but the mechanisms have not been well defined. We investigated the possible role of gastrin-induced gastric cell apoptosis in the development of gastric cancer. We examined apoptosis and the expression of Bcl-2 family proteins in INS-GAS mice of different ages, as well as in gastrin-deficient (GAS-KO) mice after gastrin-17 (G-17) infusion. In addition, we studied the effects of the gastrin/cholecystokinin-2 (CCK-2) receptor antagonist YF476 and/or histamine H2 (H-2) receptor antagonist loxtidine on apoptosis and atrophy in INS-GAS mice with or without Helicobacter felis (H. felis) infection. INS-GAS mice had age-associated increases in Bax protein expression and decreases in Bcl-2 protein expression, along with increased glandular and epithelial cell apoptosis. At 8-week gastrin infusions in GAS-KO mice resulted in a similar pattern of altered Bax and Bcl-2 expression, followed by gastric cell apoptosis. H. felis infection of INS-GAS mice led to increased apoptosis and the development of atrophy, whereas treatment with either YF476 and/or loxtidine strongly inhibited both apoptosis and atrophy. In vitro studies with Fas-expressing RGM1 cells showed that gastrin stimulation alone directly induced apoptosis via gastrin/CCK-2 receptor and synergized with FasL stimulation. These results indicate that gastrin can induce apoptosis in gastric epithelial cells and contribute to the development of gastric carcinogenesis.
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PMID:Gastrin-induced apoptosis contributes to carcinogenesis in the stomach. 1689 54

Trefoil family factor 2 (TFF2) is expressed in gastrointestinal epithelial cells where it serves to maintain mucosal integrity and promote epithelial repair. The peptide hormone, gastrin, stimulates acid secretion but also induces proliferation of the acid-secreting mucosa. Because the relationship between these peptides of overlapping function is not understood, we chose to investigate the regulatory effect of gastrin on TFF2 expression. The expression of mRNA and protein of TFF2 was determined by RT-PCR and immunohistochemical staining, respectively. A series of truncated and mutant murine TFF2 promoter constructs was generated. Promoter activity was assessed using dual luciferase reporter assays. Gastrin-responsive DNA-binding sites in the TFF2 promoter were evaluated by electrophoretic mobility shift assay. Gastrin significantly increased the level of endogenous mRNA of TFF2 in the gastrin receptor-expressing AGS-E gastric cancer cell line in a time- and dose-dependent manner. TFF2 protein expression in the gastric fundus was elevated in hypergastrinemic (INS-GAS) transgenic mice and reduced in gastrin-deficient mice. Gastrin treatment increased TFF2 promoter activity through cis-acting regions, containing CCAATA- and GC-rich enhancers. Pretreatment with Y-F476, a gastrin/CCK(B) receptor antagonist, abolished gastrin-dependent promoter activity. Inhibitors of protein kinase C (PKC), mitogen/extracellular signal-regulated kinase (MEK1), and phosphatidylinositol 3-kinase (PI 3-kinase) reduced gastrin-dependent TFF2 promoter activity, whereas an epithelial growth factor receptor (EGFR) inhibitor had no effect. We found that gastrin regulates TFF2 transcription through a GC-rich DNA-binding site and a PKC-, MEK1- and PI 3-kinase-dependent but EGFR-independent pathway. Regulation of TFF2 by gastrin may play a role in the maintenance and repair of the gastrointestinal mucosa.
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PMID:Gastrin regulates the TFF2 promoter through gastrin-responsive cis-acting elements and multiple signaling pathways. 1733 76


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