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

Over a period of 21 years 39 patients with gastrinoma were surgically treated. Thirty-three patients had total gastrectomy with two postoperative deaths, and 6 patients had a lesser procedure. The postoperative fasting gastrin levels remained elevated and did not always indicate the extent of tumor involvement. Further mobilization of tumor gastrin by provocative infusion of calcium gluceptate, 15 mg/kg of body weight, should be carried out routinely. A hepatic angiogram should be considered when the gastrin levels exceed 1,000 picograms per ml. Chemotherapy consisting of Tubercidin, Streptozotocin and 5-Fluorouracil was given to 5 patients with extensive gastrinoma. All patients felt better and gained from three to 35 pounds in weight. Since 60% of the patients died or have definite evidence of tumor activity it is assumed that the tumor growth was not inhibited and that it is malignant. Approximately 40% of the patients seem to do well despite modest elevations in gastrin levels suggesting that the retained tumor could be considered benign.
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PMID:Observations on the postoperative tumor growth behavior of certain islet cell tumors. 18 9

With better methods of diagnosis, patients will be identified earlier in the course of their disease and will often have atypical and borderline manifestations of the syndrome. Serum gastrin measurements with calcium and especially with secretin challenge will be the most important method of diagnosis. Any patient with acid hypersecretion who has a high serum gastrin level that does higher on secretin infusion should be considered to have the Zollinger-Ellison syndrome. A firm diagnosis of the Zollinger-Ellison syndrome should be made, if at all possible, prior to operation. At operation, a thorough search of the pancreas, duodenum, stomach, greater and lesser omentum and liver should be made for primary and secondary gastrinomas. If the preoperative data firmly establish the diagnosis of the Zollinger-Ellison syndrome, a total gastrectomy should be carried out even if no primary tumor is found. Similarly, a total gastrectomy should be done even if there are massive hepatic metastases. If total gastrectomy is not performed, the patient is apt to die of complications of acid hypersecretion. The only possible exceptions to the rule of always performing a total gastrectomy are in asymptomatic patients with easily excisable tumors or patients with tumors of the duodenum that are easily excisable, providing that in both instances after the excision of the tumor the output of gastric acid as measured at operation is immediately halted. All possible metastatic tumor tissue should be removed. The more tumor tissue removed, the longer the patient will survive. Metastases should be treated aggressively. They do not disappear after total gastrectomy in our experience, and they may kill patients. Patients should be followed after operation with serial measurements of serum gastrin concentrations and by hepatic scintillation scans and hepatic angiography. If hepatic metastases develop, intrahepatic artery infusions of 5-fluorouracil may slow tumor growth.
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PMID:Natural history and experience with diagnosis and treatment of the Zollinger-Ellison syndrome. 114 7

This article describes studies with four peptides, epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha), gastrin-releasing peptide/bombesin (GRP), and gastrin. The mitogenic and anti-secretory activities of EGF/TGF alpha appear to be mediated by a single class of high-affinity membrane receptors but may involve different signal transducing mechanisms. Biological activity of EGF resides in the N-terminal 42 amino acid fragment with the C-terminal undecapeptide determining binding affinity. A parenteral depot formulation of an EGF-related peptide or a small molecule agonist of the EGF receptor could have utility in treating various ulcerative disorders of the gut. Although antagonism of EGF (and thus TGF alpha) receptors and/or transducing mechanisms is frequently cited as a potential therapeutic approach to hyperproliferative diseases, blocking the action of TGF alpha, GRP, or gastrin with neutralizing antibodies or receptor antagonists did not influence the growth of a wide range of solid tumors in nude mice. These findings suggest that, unless tumor growth displays absolute dependency on one particular mitogen, antagonism of a specific growth factor is unlikely to have great effect in cancer therapy.
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PMID:Therapeutic potential of growth factors and their antagonists. 134 Oct 74

Many reports have emphasized the role of gastrin as a growth factor for normal gastrointestinal mucosa and gastrointestinal cancers. Recent studies have pointed out that this peptide acts also as a growth factor for the pancreatic cancer cell line AR42J. This effect is mediated by gastrin [cholecystokinin (CCK)-B] receptors. In the present study, we investigated gastrin (CCK-B) receptor expression in the azaserine-induced rat pancreatic carcinoma DSL-6, comparing it to normal rat pancreas, and we also characterized CCK receptor subtypes in this tumor. The results showed that there is extensive gastrin binding to the DSL-6 pancreatic carcinoma. No evidence of specific gastrin binding to normal pancreas was found. Analysis of the ability of gastrin-17-I to inhibit 125I-gastrin-I binding demonstrated that gastrin bound to a single class of receptors with a Kd of 0.21 +/- 0.04 nM and a binding capacity of 184 +/- 29 fmol/mg protein. 125I-Gastrin-I binding was inhibited by the specific CCK-B receptor antagonist L365,260 approximately 40 times more effectively than by the specific CCK-A receptor antagonist L364,718. Analysis of the ability of cholecystokinin octapeptide (CCK-8) to inhibit 125I-Bolton-Hunter-CCK-8 binding revealed two CCK binding sites, i.e., a high affinity site and a low affinity site. The observed binding affinities of CCK-8 were then introduced into the computer analysis of the dose-inhibition curve of the ability of gastrin-17-I to inhibit binding of 125I-Bolton-Hunter-CCK-8, which was significantly better fit by a three-site model than by a two-site model. The three sites meet the criteria for CCK-B, high affinity CCK-A, and low affinity CCK-A receptors. The binding capacity of CCK-B receptors constitutes 34% of the total high affinity CCK binding sites. This study demonstrated that DSL-6 pancreatic carcinoma expresses three subtypes of CCK receptors. Gastrin (CCK-B) receptors, which were not detected in normal rat pancreas, constitute about one third of the total high affinity CCK receptors. We suggest that novel expression of gastrin (CCK-B) receptors may be generated by gene mutation or amplification during carcinogenesis and may play an important role in promoting tumor growth.
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PMID:Novel expression of gastrin (cholecystokinin-B) receptors in azaserine-induced rat pancreatic carcinoma: receptor determination and characterization. 145 79

The SRIF analog octreotide (SMS 201-995) has been in clinical use for over 6 yr in the treatment of acromegaly and metastatic endocrine pancreatic and carcinoid tumors. The use of the analog in the treatment of acromegaly and TSH-secreting tumors is beyond the scope of this clinical review. Patient acceptance of the analog, given chronically by the sc route, has been excellent and side effects have been few with the exception of the development of gallstones. In endocrine pancreatic and carcinoid tumors the hypersecretion of hormones such as VIP, glucagon, and gastrin and the secretory products of carcinoid tumors (e.g. 5-hydroxytryptamine and tachykinins) and their clinical effects may be successfully blocked. This allows excellent palliation of such tumors and often enables the patients to return home and lead normal social lives. Initial hopes that long-term octreotide therapy would be an effective antitumor drug, reducing tumor growth, based on experimental animal models and human tumor cell lines, have not been born out in clinical practice. A reduction in gut tumor bulk due to octreotide, rarely or never occurs as a sustained phenomenon. Eventually a decrease in, and finally an absence of, clinical effectiveness occurs despite the reintroduction of other treatment modalities.
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PMID:Clinical review 23: The use of the long-acting somatostatin analog octreotide in the treatment of gut neuroendocrine tumors. 164 13

Nude mice bearing xenografts of HT-29 human colon cancer cell line were treated for 4 weeks with a [D-Trp6] agonist of luteinizing hormone releasing hormone (LH-RH), somatostatin analogue (RC-160), and bombesin/gastrin releasing peptide antagonist (RC-3095). Some inhibitory effect of [D-Trp6] LH-RH microcapsules releasing 25 micrograms/day on tumor growth was observed that could be due to sex steroid deprivation, but the inhibition was not statistically significant. Microcapsules of RC-160, releasing 50 micrograms/day, significantly reduced tumor volume after 21 and 24 days of treatment, but at the end of the experiment the inhibition in tumor volume and weight was not significant. Bombesin/gastrin releasing peptide antagonist RC-3095, at a dose of 20 micrograms/day administered by daily s.c. injections or by continuous infusion using Alzet osmotic minipumps, had the greatest inhibitory effect on tumor growth. Tumor volume, percentage change in tumor volume, and tumor weights were significantly decreased in both groups treated with RC-3095. This is the first report on inhibition of human colon cancer growth in vivo by bombesin antagonists.
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PMID:Inhibition of growth of HT-29 human colon cancer xenografts in nude mice by treatment with bombesin/gastrin releasing peptide antagonist (RC-3095). 168 40

The authors have established a long-term tissue culture cell line (BON) derived from a metastatic human carcinoid tumor of the pancreas. The cells have been in continuous passage for 46 months. Tissue culture cells produce tumors in a dose-dependent fashion after SC inoculation of cell suspensions in athymic nude mice. BON tumors, grown in nude mice, are histologically identical to the original tumor; they possess gastrin and somatostatin receptors, synthesize serotonin and chromogranin A, and have a doubling time of approximately 13 days. The antiproliferative effects of the long-acting somatostatin analogue, SMS 201-995 (300 micrograms/kg, t.i.d.), and 2% alpha-difluoromethylornithine on BON xenografts in nude mice were examined. Tumor size was significantly decreased by day 14 of treatment with either agent and at all points of analysis thereafter until the animals were killed (day 33). In addition, tumor weight, DNA, RNA, and protein contents were significantly decreased in treated mice compared with controls. Establishment of this human carcinoid xenograft line, BON, provides an excellent model to study further the biological behavior of carcinoid tumors and the in vivo effect of chemotherapeutic agents on tumor growth.
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PMID:Establishment and characterization of a human carcinoid in nude mice and effect of various agents on tumor growth. 171 29

Gastrin stimulates the growth of some human colon adenocarcinomas grown in vitro or as xenografts in nude mice. To evaluate the possibility of elevated plasma gastrin levels in patients with adenomatous polyps or colorectal cancer, we carried out a radioimmunoassay in subjects fasting overnight and undergoing colonoscopy. The study included 190 patients who were divided into three groups: controls (n = 65), those with benign adenomas (n = 63), and those with adenocarcinomas (n = 62). The mean values of plasma gastrin in the cancer group (112.71 +/- 16.65 pg/ml) were significantly higher than those of the control group (40.41 +/- 1.88 pg/ml) as well as those of the polyp group. Mean plasma gastrin values in the polyp group (54.27 +/- 5.29 pg/ml) were also significantly higher than those of the control group. In the cancer group, 32 of 62 patients (51.6%) had gastrin levels greater than the control mean +2 SD, as opposed to only 10 of 63 (15.9%) in the polyp group. The number, size, histologic type, and presence of dysplasia in the polyp group and the location or Dukes' stage in the cancer group had no significant influence on gastrin levels in this study. Preliminary results in cancer patients with elevated preoperative gastrin levels show a postoperative reduction in six of seven patients. The exact cause and role of hypergastrinemia in tumor growth in such patients remains to be determined. Measurements taken both before and after colectomy coupled with a systematic search for specific gastrin receptors would be useful.
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PMID:Elevated serum gastrin levels in patients with colorectal neoplasia. 174 82

The influence of gastric resection on the Zollinger-Ellison syndrome (ZES) in eight children was first reported to the Central Surgical Association 26 years ago. That report showed that the three children who had less than total gastrectomy were all dead with complications of gastric acid hypersecretion, although the five children who had total gastrectomy were living and well. During the past quarter of the century, the development of effective gastric acid inhibitors has prompted a greater emphasis on medical management in the ZES. The role of the surgeon and total gastrectomy remains controversial. Follow-up of the five young patients who had total gastrectomy shows that only one patient was dead with tumor 14 years after total gastrectomy and that the remaining four patients were alive 30, 29, 28, and 27 years, respectively, after total gastrectomy. Growth and activity have been near normal. All patients have had proven metastatic islet-cell carcinoma documented at some time in the course of the disease (lymph nodes in three patients and liver metastasis in two patients). Only one of the four living patients with total gastrectomy had a normal serum gastrin level and no apparent tumor. Gastrinoma tumor growth appears to be less aggressive in children than in adults. Complete excision of gastrinomas is possible in some patients with ZES. When hypergastrinemia persists, total gastrectomy may be preferable to lifelong medical management with gastric acid inhibitors in children and young adults with ZES.
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PMID:Zollinger-Ellison syndrome in children: a 25-year follow-up. 192 58

We have used the gastrinoma syndrome to examine the effects of SMS. Acutely, SMS decreased acid secretion and restored the BAO/MAO to normal in eight of eight patients. Basal and secretin-stimulated gastrin responses were suppressed but not normalized. Treatment for up to 2 years with SMS controlled symptoms, suppressed serum gastrin, and suppressed acid secretion. Treatment for 1 year or longer decreased tumor secretion of gastrin and diminished basal acid secretion, an effect that persisted for 48 hours after withdrawal of SMS. SMS treatment arrested progression of tumor growth only in patients in whom there was a reduction in gastrin and gastric acid secretion. In patients with metastatic disease who had high levels of gastrin, SMS treatment for 5 to 24 months did not inhibit tumor growth or decrease gastrin levels. In those patients in whom a reduction in the blood flow to liver tumors was shown angiographically, there was a progressive improvement in hormone secretion and in tumor size in the ensuing year of treatment, suggesting that a major target of SMS is that vascular supply of the tumors. Tumors shown to produce peptides other than gastrin, for example ACTH, were found to be markedly resistant to the action of SMS and continued to grow in an unbridled manner.
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PMID:The use of somatostatin analog in gastroenteropancreatic tumors other than carcinoid. 240 20


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