Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01350 (gastrin)
 9,683 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ulcer healing involves expression of various growth factors including hepatocyte growth factor (HGF) at the ulcer margin and the rise in plasma gastrin but the effects of locally applied HGF and gastrin, which are known to act as trophic factors for the gastric mucosa, with or without neutralizing antibodies against HGF and gastrin or COX-1 and COX-2 inhibitors on ulcer healing and the expression of cyclooxygenase (COX)-1 and COX-2 during this healing have been little studied. Rats with gastric ulcers induced by serosal application of acetic acid (ulcer area 28 mm2) received a submucosal injection of either: 1)vehicle (saline), 2) HGF and 3) gastrin with or without neutralizing antibodies against HGF and gastrin or treatment with indomethacin (2 mg/kg-d i.p.), a non-specific inhibitor of COX, or NS-398 (5 mg/kg-d i.g.) and Vioxx (10 mg/kg-d i.g.), both highly specific COX-2 inhibitors. Each growth factor and specific antibodies against HGF and gastrin (100 ng/100 microl each) were injected just around the ulcer immediately after ulcer induction and this local application was repeated at day 2 following anesthesia and laparotomy. At day 13 and 21, the area of ulcers was determined by planimetry, the gastric blood flow (GBF) at ulcer margin was examined by H2-gas clearance technique and mucosal generation of PGE2 and the expression of COX-1 and COX-2 mRNA in the non-ulcerated and ulcerated gastric mucosa was analyzed using RT-PCR. The gastric ulcers healed progressively within 21 days and this effect was accompanied by significant increase in the GBF at the ulcer margin and expression of COX-2 mRNA and COX-2 protein at the ulcer area. Treatment with HGF and gastrin significantly accelerated the rate of ulcer healing and raised GBF at ulcer margin causing further significant upregulation of COX-2 mRNA and COX-2 protein (but not of COX-1 mRNA ) in the ulcerated mucosa. The upregulation of COX-2 mRNA induced by HGF was significantly attenuated by the concurrent local treatment with antibody against this growth peptide. Indomethacin and both COX-2 inhibitors significantly prolonged the ulcer healing, while suppressing the generation of PGE2 in non-ulcerated and ulcerated gastric mucosa and the GBF at ulcer margin. The acceleration of ulcer healing by HGF and gastrin and accompanying rise in the GBF at ulcer margin were significantly attenuated by the concurrent treatment with indomethacin or NS-398 and Vioxx. HGF injections produced a significant rise in the plasma gastrin levels and this was significantly attenuated by the cotreatment with NS-398. We conclude that 1) neutralization of HGF and gastrin by their specificantibodies delays ulcer healing due fall in the microcirculation around the ulcer and a decrease in the COX-2 expression, 2) COX-2 derived prostaglandins may play an important role in acceleration of the ulcer healing by various growth factors including HGF and gastrin, 3) enhancement of the local pool for growth factors such as HGF and gastrin at the ulcer site could offer a new modality for treatment of gastric ulcer.
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PMID:Involvement of cyclooxygenase (COX)-2 products in acceleration of ulcer healing by gastrin and hepatocyte growth factor. 1119 47

Helicobacter pylori (HP) infection is usually accompanied by an increased plasma level of gastrin, a potent mitogen able to induce cyclooxygenase (COX)-2. This study examined (a) the seroprevalence of HP, its cytotoxic protein, CagA, and cytokines (tumor necrosis factor alpha, interleukins 1beta and 8) in 80 patients with colorectal cancers, before and after the removal of tumor, compared with 160 age- and gender-matched controls; (b) the gene expression of gastrin and its receptors (CCKB-R) in the cancer tissue, (c) the plasma levels and tumor tissue contents of gastrin, and (d) the mRNA expression of COX-1, COX-2, and apoptotic proteins (Bax and Bcl2) in cancer tissue and intact colonic mucosa. Anti-HP IgG, anti-CagA IgG seroprevalence, and cytokine levels were analyzed by enzyme-linked immunosorbent assay tests; gene expressions of gastrin, CCKB-R, COX-1, COX-2, Bax, and Bcl2 by reverse transcriptase polymerase chain reaction; and gastrin by radioimmunoassay. The seroprevalence of HP, especially that expressing CagA, was significantly higher in cancer patients than in controls and did not change 1 week after tumor resection while plasma cytokines were significantly reduced after this operation. Both gastrin and CCKB-R mRNA were detected in the cancer tissue and the resection margin; similarly, COX-2 mRNA was expressed in most of cancers and their resection margin but not in intact colonic mucosa, where only COX-1 was detected. The colorectal cancer tissue contained several folds more immunoreactive gastrin than cancer resection margin and many folds more than the intact colonic mucosa. We conclude that colon adenocarcinoma and its resection margin overexpress gastrin, its receptors, CCKB-R, and COX-2, and that HP infection may contribute to colonic cancerogenesis via overexpression of gastrin and COX-2, which may account for the stimulation of the tumor growth and the reduction in apoptosis as documented by enhanced mRNA expression of anti-apoptotic Bcl2 over proapoptotic Bax proteins.
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PMID:Helicobacter pylori infection, gastrin, cyclooxygenase-2, and apoptosis in colorectal cancer. 1151 78

Gastroduodenal ulcerations have worldwide distribution and the infection with Helicobacter pylori (HP) has been implicated in pathogenesis of this disease. The HP infection is usually accompanied by hypergastrinemia and enhanced generation of prostaglandins (PG), both implicated in the pathogenesis of peptic ulcerations but no study has been undertaken to assess the relationship between the HP infection and coexpression of gastrin and cyclooxygenases (COX), the rate limiting enzymes in the PG production. Since HP infection, usually accompanying peptic ulcerations, results in increased release of gastrin, a potent gastric mitogen that might be capable to induce COX-2 and to generate PG, we decided 1) to compare the seroprevalence of HP and its cytotoxic protein, CagA, in gastric ulcer patients with those in age- and gender-matched controls; 2) to determine the gene expression of gastrin and its receptors (CCK(B)-R) at the margin of gastric ulcer and in the mucosa of antrum and corpus before and after successful eradication of HP, 3) to assess the plasma levels and gastric luminal contents of gastrin before and after HP eradication and 4) to examine the mRNA and enzyme protein expression of COX-1 and COX-2 as well as the PGE2 generation in ulcer margin tissue and gastric antral and fundic mucosa before and after the HP eradication. The trial material included 20 patients with gastric ulcer and 40 age- and gender-matched controls. Anti-HP and anti-CagA IgG seroprevalence was estimated by specific antisera using ELISA tests. Gene expressions of gastrin, CCK(B)-R, COX-1 and COX-2 were examined using RT-PCR with beta-actin as a reference and employing Western blotting for COX-2 expression, while gastrin and PGE2 were measured by RIA. All gastric ulcers were located at smaller curvature within the antral mucosal area. The seroprevalence of HP, especially that expressing CagA, was significantly higher in gastric ulcers (85%) than in controls (62.5%). Both gastrin and CCK(B)-R mRNA were detected by RT-PCR in ulcer margin and gastrin mRNA was overexpressed in remaining antral mucosa, while CCK(B)-R mRNA was overexpressed in fundic mucosa of HP infected patients. Similarly, COX-2 mRNA and protein were found in margin of gastric ulcer and in the HP infected antral and fundic mucosa but not in the mucosa of HP eradicated patients in whom ulcers completely healed and gastrin was expressed only in antrum, CCK(B)-R only in corpus, while COX-1 was detected both in antrum and corpus. HP positive gastric ulcer patients showed about three times higher levels of plasma immunoreactive gastrin and about 50% higher luminal gastrin contents than the HP negative controls and this increased plasma and luminal gastrin was normalized following the HP eradication. A significant fall in gastrin and CCK(B)-R mRNA expression was noticed six weeks after HP eradication in gastric antral and fundic mucosa, while COX-2 mRNA completely disappeared after this treatment. We conclude that 1) HP infected gastric ulcer margin coexpresses gastrin, its receptors (CCK(B)-R), and COX-2; 2) HP infection may be implicated in gastric ulceration via increased release of gastrin that could be responsible for the overexpression of COX-2 that in turn could help ulcer healing through the stimulation of mucosal cell growth, restoration of the glandular structure and angiogenesis in the ulcer area and 3) gastrin produced in HP infected antral mucosa seems to be involved in the induction of COX-2 and PG production by this enzyme and this may contribute to the ulcer healing.
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PMID:Implication of gastrin in cyclooxygenase-2 expression in Helicobacter pylori infected gastric ulceration. 1151 93

In rats, central vagal stimulation by thyrotropin-releasing hormone protects against ethanol-induced gastric damage by muscarinic release of prostaglandins. In contrast, gastroprotection following capsaicin-induced stimulation of afferent neurons is prostaglandin-independent. Capsaicin-evoked protection is abolished by blockade of calcitonin gene-related peptide (CGRP) receptors and inhibition of nitric oxide (NO) synthase. Various peptides including gastrin 17, cholecystokinin octapeptide, thyrotropin-releasing hormone, bombesin, corticotropin-releasing factor, epidermal growth factor, peptide YY, neurokinin A analogs and intragastric peptone exert gastroprotection that is abolished by afferent nerve denervation, blockade of CGRP receptors and inhibition of NO synthase. Indomethacin attenuates the protection of some peptides but has no effect with others. The hyperemic response to peptides is mediated by the afferent nerve/CGRP/NO system without contribution of prostaglandins. Furthermore, it was shown that NKA analogs exert afferent nerve-, CGRP- and NO-dependent gastroprotection in the face of substantial reduction of gastric mucosal blood flow indicating that gastroprotection is not necessarily mediated by mucosal hyperemia. In the rat stomach with functioning afferent nerves neither selective inhibition of cyclooxygenase (COX)-1 nor COX-2 is ulcerogenic and only simultaneous inhibition of both COX isoenzymes induees mucosal lesions. In the face of pending injury such as intragastric acid a COX-1 inhibitor evokes dose-dependent damage whereas COX-2 inhibitors are not injurious as long as the function of afferent nerves is not impaired. After afferent nerve denervation, however, COX-2 inhibitors or dexamethasone which suppresses the acid-induced up-regulation of COX-2 are highly ulcerogenic. In conclusion, release of prostaglandins following nerve stimulation can mediate protective effects under certain conditions but is not a prerequisite for neurally mediated mucosal defense. Prostaglandins are of particular importance for the maintenance of gastric mucosal integrity when neuronal defense mechanisms are impaired.
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PMID:Neural aspects of prostaglandin involvement in gastric mucosal defense. 1178 58

An immunohistochemical study of cyclooxygenase (COX)-2 expression in pancreatic endocrine tumors (PET) was carried out, and the expression of COX-2 was compared with pathological features, the expression of several markers (hormones, vascular endothelial growth factor, single-stranded DNA, and the Ki-67 labeling index [LI]). Twenty PET, including 10 metastasizing cases (tumor size: 3-8 cm) and 10 non-metastasizing cases (tumor size: 0.3-8 cm) were studied. Tumors with a high level of COX-2 expression were placed in the H group, and the remaining tumors were placed in the L group. The H group was comprised of 13 tumors: all 10 of the metastasizing cases and three of the non-metastasizing cases. There were significant differences in tumor size between the two groups (H group 46.5 mm; L group 0.9 mm). There were significant differences in the presence of the following histological criteria for malignancy: pleomorphism (H group 13/13; L group 1/7), mitotic activity (H group 2.9; L group 0) and/or angioinvasion (H group 13/13; L group 1/7); and there were also significant differences in the number of cases that expressed ectopic hormones (gastrin, vasoactive intestinal peptide, serotonin and calcitonin; H group 12/13; L group 2/7) and in the Ki-67 LI (H group 8.3%; L group 0.4%). The distribution of COX-2-positive cells tended to be similar to the distribution of Ki-67-positive cells. Our data show that COX-2 is frequently upregulated in malignant PET and that there is a close relationship between COX-2 expression and tumor progression/proliferative activity.
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PMID:Immunohistochemical analysis of cyclooxygenase (COX)-2 expression in pancreatic endocrine tumors: association with tumor progression and proliferation. 1188 29

Malt-lymphoma, gastrin and COX-2 interaction. Low grade, mucosal associated lymphoid tissue (MALT)-lymphoma is an unique among gastric malignancies where causal involvement of Helicobacter pylori (H. pylori) infection has been proposed based on complete regression of the tumor following the eradication therapy. In this report ten primary, low-grade MALT-lymphomas have been examined before and 6 months after one week of successful eradication therapy (clarithromycin + amoxicillin + omeprazole). Gastric biopsy samples from tumor and intact antrum and corpus mucosa were obtained during endoscopy before and after eradication for assessment of expression of gastrin and gastrin receptor (CCKB-R) as well as cyclooxygenase (COX)-1 and COX-2 using RT-PCR. The gastric lumen and serum gastrin and mucosal and tumor tissue PGE2 biosynthesis were determined by RIA before and after H. pylori eradication. Eradication of H. pylori resulted in complete endoscopic and histological remission of MALT-lymphoma in 9 out of 10 patients as assessed 6 months after this eradication. Before eradication, the mRNA expression for gastrin and CCKB-R as well as mRNA expression for COX-1 and COX-2 were observed in tumor tissue and infected mucosa, while corpus mucosa expressed only CCKB-R and antrum mucosa only gastrin. Six months upon the eradication when MALT-lymphoma completely regressed both endoscopically and histologically in 9 of 10 tested subjects, the expression of gastrin and COX-2 disappeared from the former area of MALT-lymphoma tumor. Gastrin mRNA remained detectable only in antrum mucosa, CCKB-R mRNA in corpus mucosa and COX-1 mRNA both in antrum and corpus mucosa. Gastric luminal and serum gastrin levels and gastric mucosa and tumor PGE2, which were greatly elevated before eradication, became normalized after this procedure. This study demonstrates that low-grade MALT-lymphoma is linked to H. pylori infection which may promote the expression and excessive release of gastrin and COX-2 expression that could be involved in the pathogenesis of MALT-lymphoma.
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PMID:Gastric MALT-lymphoma, gastrin and cyclooxygenases. 1201 12

We examined expression, function, and regulation of the cyclooxygenase (COX)-2 gene in gastric parietal cells. COX-2-specific mRNA was isolated from purified (>95%) canine gastric parietal cells in primary culture and measured by Northern blots using a human COX-2 cDNA probe. Carbachol was the most potent inducer of COX-2 gene expression. Gastrin and histamine exhibited minor stimulatory effects. Carbachol-stimulated expression was inhibited by intracellular Ca(2+) chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-AM (90%), protein kinase C (PKC) inhibitor GF-109203X (48%), and p38 kinase inhibitor SB-203580 (48%). Nuclear factor (NF)-kappaB inhibitor 1-pyrrolidinecarbodithioic acid inhibited carbachol-stimulated expression by 80%. Similar results were observed in the presence of adenoviral vector Ad.dom.neg.IkappaB, which expresses a repressor of NF-kappaB. Addition of SB-203580 with Ad.dom.neg.IkappaB almost completely blocked carbachol stimulation of COX-2 gene expression. We examined the effect of carbachol on PGE(2) release by enzyme-linked immunoassay. Carbachol induced PGE(2) release. Ad.dom.neg.IkappaB, alone or with SB-203580, produced, respectively, partial (70%) and almost complete (>80%) inhibition of carbachol-stimulated PGE(2) production. Selective COX-2 inhibitor NS-398 blocked carbachol-stimulated PGE(2) release without affecting basal PGE(2) production. In contrast, indomethacin inhibited both basal and carbachol-stimulated PGE(2) release. Carbachol induces COX-2 gene expression in the parietal cells through signaling pathways that involve intracellular Ca(2+), PKC, p38 kinase, and activation of NF-kappaB. The functional significance of these effects seems to be stimulation of PGE(2) release.
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PMID:Regulation and function of COX-2 gene expression in isolated gastric parietal cells. 1201 33

Colorectal cancers (CRCs) are one of the most common forms of cancer in Poland and one of the leading causes of death. The tumors have been attributed to genetic, dietary, and other environmental factors, but recently growth factors such as gastrin have also been implicated in the carcinogenesis. The relationship between plasma amidated and nonamidated gastrin in CRCs is controversial. This study was designed (1) to determine the plasma levels of progastrin and amidated gastrin in 50 CRC patients before and 3-6 months after removal of the tumor, (2) to determine the tumor concentrations of these gastrin peptides and the level of expression for gastrin mRNA and gastrin/CCK(B) receptor mRNA, (3) to examine the expression of cyclooxygenase COX-1 and COX-2 mRNA in CRC tissue, and (4) to compare the prevalence of Hp and its cytotoxic protein, CagA, and cytokines (TNFalpha, IL-1beta, and IL-8) in CRCs, before and after removal of tumor. It was found that the CRC, its resection margin, and the plasma contained severalfold higher levels of progastrin than of amidated gastrins and that the removal of the CRC tumor resulted in a marked reduction in plasma progastrin level without a significant alteration in plasma levels of amidated gastrins. Both gastrin and CCK(B)-R mRNA were detected in the cancer tissue and resection margin by RT-PCR, and similarly, COX-1 and COX-2 mRNA were expressed in these tissues of most CRCs. The seroprevalence of Hp, especially that expressing CagA, and levels of IL-1beta, but not other cytokines, were significantly higher in CRC patients than in 100 age-, gender-, and profession-matched controls and did not change significantly about 3-6 months after tumor resection. We conclude that (1) the CRC and its margin contain large amounts of progastrin and show gene expression of gastrin, CCK(B)-R, and COX-2; (2) removal of the CRC markedly reduces the plasma concentrations of progastrin; (3) the Hp infection rate is higher in CRC, and this may contribute to colorectal cancerogenesis via enhancement of progastrin and gastrin release; and (4) plasma progastrin concentrations might serve as a biomarker of CRC.
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PMID:Progastrin and cyclooxygenase-2 in colorectal cancer. 1235 42

Gastrin, PGs, and growth factors have important roles in maintaining gastrointestinal mucosal integrity. Cyclooxygenases (COX-1 and COX-2) are the key enzymes involved in PG synthesis. This study aimed to clarify the mechanisms of gastric mucosal protection by gastrin. Fasted rats were administered subcutaneous gastrin 17 with or without gastrin receptor antagonist YM022 pretreatment. Heparin-binding epidermal growth factor-like growth factor (HB-EGF) and COX-2 expression were examined using Western blot analysis. Another series of experiments investigated 1) PGE(2) levels in gastric mucosa, 2) the protective action of gastrin against gastric damage by acidified ethanol, 3) the effects of a specific HB-EGF-neutralizing antibody on gastrin-induced COX-2 expression, and 4) the effects of a specific COX-2 inhibitor NS-398 on PGE(2) synthesis and the mucosal protection afforded by gastrin. Gastrin dose-dependently increased HB-EGF, COX-2 expression, and PGE(2) levels and reduced gastric damage. However, pretreatment with YM022 dose-dependently abolished such effects of gastrin. A specific HB-EGF- neutralizing antibody and an EGF receptor inhibitor decreased gastrin-induced COX-2 expression. NS-398 blocked gastrin-induced PGE(2) synthesis and mucosal protection. In conclusion, this study demonstrates that gastrin enhances gastric mucosal integrity through COX-2, which is partially mediated by HB-EGF, and PGE(2) upregulation in rats.
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PMID:Gastrin enhances gastric mucosal integrity through cyclooxygenase-2 upregulation in rats. 1238 95

Proton pump inhibitors (PPIs) are antiulcer agents that have both gastric antisecretory and mucosal protective actions. The mechanisms of PPI-induced gastric mucosal protection are not known. The present study was designed to examine the mechanism for lansoprazole-induced gastric mucosal protection in rats. Rats were given 0.5, 5, and 50 mg/kg/day lansoprazole alone or both lansoprazole (50 mg/kg/day) and a specific gastrin receptor antagonist 3R-1-(2,2-diethoxyethyl)-((4-methylphenyl)amino-carbonyl methyl)-3-((4-methylphenyl)ureidoindoline-2- one) (AG-041R) (3, 10, and 30 mg/kg/day) for 14 days. Serum gastrin concentrations were measured. The expression of cyclooxygenases (COX-1 and COX-2) in the gastric mucosa was analyzed using Western blotting and immunohistochemical staining. Another series of rats was used to examine the 1) levels of prostaglandin (PG) E2 in gastric mucosa, 2) influences of the drugs on gastric damage caused by absolute ethanol, and 3) effects of a COX-2-specific inhibitor on PGE2 in the gastric mucosa and the mucosal protection afforded by lansoprazole. Lansoprazole dose dependently increased the serum gastrin concentration and enhanced the mucosal expression of COX-2 but not that of COX-1. Lansoprazole increased gastric mucosal PGE2 and reduced gastric damage caused by ethanol. Concomitant administration of AG-041R abolished the lansoprazole-induced COX-2 expression, and increased mucosal PGE2 and mucosal protection. A specific COX-2 inhibitor blocked the lansoprazole-induced increase in mucosal PGE2 and mucosal protection. Activation of gastrin receptors by endogenous gastrin has a pivotal role in the effects of lansoprazole on COX-2 up-regulation and mucosal protection in the rat stomach.
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PMID:Lansoprazole induces mucosal protection through gastrin receptor-dependent up-regulation of cyclooxygenase-2 in rats. 1243 55


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