Antral release of gastrin and somatostatin in duodenal ulcer and control subjects.

Organ culture was used to compare gastrin and somatostatin release from cultured antral mucosa obtained from duodenal ulcer and non-ulcer (control) subjects. In response to dibutyryl cyclic AMP (DBCAMP) cultured antral mucosal explants from patients with a history of duodenal ulcer released a greater proportion of antral gastrin into the medium than did antral mucosal explants from non-ulcer subjects. Somatostatin release from antral mucosa from duodenal ulcer patients was substantially less than somatostatin released by antral explants from non-ulcer subjects. In the non-ulcer subjects there was a direct positive correlation between the amounts of antral somatostatin and gastrin released into the culture medium (r = 0.64, less than p 0.01). In the duodenal ulcer patients, however, there was no correlation between gastrin release and somatostatin release from antral mucosa ( r = 0.09; p greater than 0.2). Results of these studies identify enhanced gastrin release in response to stimulation and decreased release of somatostatin from antral mucosa of duodenal ulcer patients. These alterations in paracrine relationships of antral somatostatin and gastrin in duodenal ulcer subjects may contribute, at least in part, to the pathogenesis of duodenal ulcer disease.     

A novel deletion of the MEN1 gene in a large family of multiple endocrine neoplasia type 1 (MEN1) with aggressive phenotype

Context The MEN1 syndrome is associated with parathyroid, pancreatic and pituitary tumours and is caused by mutations in the MEN1 gene. In general, there is no genotype–phenotype correlation. Objectives To characterize a large family with MEN1 with aggressive tumour behaviour: malignant pancreatic endocrine tumours were present in five affected subjects and were the presenting features in three subjects. Design The coding region of MEN1 was sequenced. Gene copy number analysis was performed by multiplex ligation‐dependent probe amplification (MLPA) and array comparative genomic hybridization (aCGH). Loss of heterozygosity (LOH) in tumour tissue was studied by microsatellite analysis. Insulin‐like growth factor II (IGF‐II) and CDKN1C/p57KIP2 expression were investigated by immunohistochemistry. Results Mutation screening by conventional PCR sequence analysis of patients’ peripheral blood DNA did not reveal any mutation in the MEN1 or CDKN1B gene. Gene copy number analysis by MLPA and aCGH demonstrated a novel monoallelic deletion of 5 kb genomic DNA involving the MEN1 promoter and exons 1 and 2. LOH analysis indicated somatic deletion of maternal chromosome 11, including MEN1 locus (11q13) and 11p15 imprinting control regions (ICR). Methylation analysis of ICR demonstrated ICR1 hypermethylation and ICR2 hypomethylation in the tumour specimens. ICR1 and ICR2 control the expression of IGF‐2 and CDKN1C/p57KIP2, respectively. Immunohistochemistry showed that expression of paternally expressed IGF‐2 was up‐regulated and the maternally expressed CDKN1C/p57KIP2 was lost in the pancreatic endocrine tumours. Conclusions Gene copy number analysis by MLPA should be considered in patients with negative conventional mutation screening. Although large MEN1 deletion causes MEN1, disruption of imprinted CDKN1C/p57KIP2 and IGF‐2 gene expression may contribute to tumour progression and aggressive phenotype.     

No evidence of germline mutation or somatic deletion of the MEN1 gene in a case of familial multiple endocrine neoplasia type 1 (MEN1)

The MEN1 gene has recently been cloned as the gene responsible for multiple endocrine neoplasia type 1 (MEN1) and its germline mutations have been identified in a number of familial MEN1 patients. However, mutation-negative cases have also been reported in some MEN1 families. We report here a Japanese MEN1 family, including a proband with no evidence of MEN1 gene mutation. The proband (51 y.o., female) had three major MEN1 lesions, including primary hyperparathyroidism (HP), prolactinoma, and pancreatic tumor. Her father and brother had HP, and her daughter had both HP and prolactinoma. When we analyzed the proband for a germline mutation of the MEN1 gene, the direct sequencing analysis showed no mutation in the coding region, on the promoter, 5' and 3' untranslated regions of the MEN1 gene. We next examined the loss of heterozygosity (LOH) in the proband's parathyroid tumors using two benign polymorphisms (C2249G in intron 1 and 2248del3 in exon 10) in the MEN1 gene to detect LOH. LOH was not found in any of the four separate regions of the tumor tissues.     

Assay of gastrin and somatostatin in gastric antrum tissues of children with chronic gastritis and duodenal ulcer

AIM: To study the expressions of gastrin (GAS) and somatostatin (SS) in gastric antrum tissues of children with chronic gastritis and duodenal ulcer and their role in pathogenic mechanism. METHODS: Specimens of gastric antrum mucosa from 83 children were retrospectively analyzed. Expressions of GAS and SS in gastric antrum tissues were assayed by the immunohistochemical En Vision method. RESULTS: The expressions of GAS in chronic gastritis Hp group (group A), chronic gastritis Hp- group (group B), the duodenal ulcer Hp group (group C), duodenal ulcer Hp- group (group D), and normal control group (group E) were 28.50 4.55, 19.60 2.49, 22.69 2.71, 25.33 4.76, and 18.80 2.36, respectively. The value in groups A-D was higher than that in group E. The difference was not statistically significant. The expressions of SS in groups A-E were 15.47 1.44, 17.29 2.04, 15.30 1.38, 13.11 0.93 and 12.14 1.68, respectively. The value in groups A-D was higher than that in group E. The difference was also not statistically significant. CONCLUSION: The expressions of GAS and SS are increased in children with chronic gastritis and duodenal ulcer.     

Antral gastrin and somatostatin cell populations in rats after chronic administration of histamine

Variations in the size of the antral G and D cell populations under the effect of chronic stimulation of acid secretion with histamine were investigated in male Wistar rats. Osmotic minipumps delivering either 0.9% saline or histamine dihydrochloride (4.5 mg/kg/h) were implanted subcutaneously in gastric-fistula rats. Gastric secretion was collected prior to the implantation of the pump, after 7 days and after 14 days. Total antral G and D cell numbers and the G/D ratio were estimated at the end of the experiment. Administration of histamine during 14 days did not induce significant changes in the number of either G or D cells in the antrum despite a 3-fold increase in acid secretion.     

Effect of glucagon-like peptide-1 on gastric somatostatin and gastrin secretion in the rat

The effect of glucagon-like peptide-1 (GLP-1) amide on gastric somatostatin and gastrin secretion was investigated in the isolated, vascularly perfused rat stomach preparation. GLP-1 (7-36) amide, 10(-12) to 10(-7)M, dose-dependently increased gastric somatostatin release, achieving maximal stimulation (314 +/- 15% above basal) at the highest dose. The somatostatin response to 10(-8)M GLP-1 (7-36) amide was not affected by concomitant perfusion with tetrodotoxin. GLP-1 (1-36) amide did not affect somatostatin release. Both basal and acetylcholine-stimulated gastrin were inhibited by GLP-1 (7-36) amide but were not influenced by GLP-1 (1-36) amide. In is concluded that GLP-1 (7-36) amide is the biologically effective peptide that stimulates gastric somatostatin and inhibits gastrin secretion, probably via non-neural pathways. GLP-1 (7-36) amide-induced inhibition of gastric acid secretion may, at least in part, be due to enhanced somatostatin and/or decreased gastrin release.     

Correlation between expression of gastrin, somatostatin and cell apoptosis regulation gene bcl-2／bax in large intestine carcinoma

AIM: To explore the correlation between expression of somatostatin (SS), gastrin (GAS) and cell apoptosis regulation gene bcl-2/bax in large intestine carcinoma. METHODS: Sixty-two large intestine cancer tissue samples were randomly and retrospectively selected from patients with large intestine carcinoma. Immunohistochemical staining for bcl-2, bax, GAS, SS was performed according to the standard streptavidin-biotin-peroxidase (S-P) method. According to the semi-quantitative integral evaluation, SS and GAS were divided into three groups as follows. Scores 1-3 were defined as the low expression group, 4-8 as the intermediate expression group, 9-16 as the high expression group. Bax and bcl-2 protein expressions in different GAS and SS expression groups of large intestine carcinoma were assessed. RESULTS: The positive expression rate of bax had a prominent difference between SS and GAS high, intermediate and low expression groups (P<0.05, x2SS = 9.246; P<0.05, x2GAs = 6.981). The positive expression rate of bax in SS high (80.0%, 8/10) and intermediate (76.5%, 13/17) expression groups was higher than that in low expression group (40.0%, 14/35) (P<0.05, X2high vslow = 5.242; P<0.05, x2middle vs low = 6.097). The positive expression rate of bax in GAS high expression group (27.3%, 3/8) was lower than that in low expression group (69.4%, 25/36) (P<0.05, x2 = 4.594). However, bax expression in GAS intermediate expression group (46.7%, 7/15) was lower than that in low expression group, but not statistically significant. The positive expression rate of bcl-2 had a prominent difference between SS and GAS high, intermediate and low expression groups (P<0.05, x2ss = 7.178; P<0.05, x2GAS = 13.831). The positive expression rate of bcl-2 in GAS high (90.9%, 10/11) and intermediate (86.7%, 13/15) expression groups was higher than that in low expression group (44.4%, 16/36) (P<0.05, x2high,vslow = 5.600; P<0.05, x2middle vs low = 7.695). However, the positive expression rate of bcl-2 in SS high (40. 0%, 4/10) and intermediate (47.1%, 8/9) expression groups was lower than that in low expression group (77.1%, 27/35) (P<0.05, x2high vs low = 4.710; P<0.05, x2middle vs low = 4.706). There was a significant positive correlation between the integral ratio of GAS to SS and the integral of bcl-2 (P<0.01, r = 0.340). However, there was a negative correlation between the integral ratio of GAS to the SS and bax the integral of (P<0.05, r= -0.299). CONCLUSION: The regulation and control of gastrin, somatostatin in cell apoptosis of large intestine carcinoma may be directly related to the abnormal expression of bcl-2, bax.     

胃泌素及生长抑素对人大肠癌细胞的调节

目的观察五肽胃泌素（ＰＧ）、胃泌素受体拮抗剂丙谷胺（ＰＧｌ）和生长抑素（ＳＳ）长效类似物ＳＭＳ２０１＿９９５对体外培养人大肠癌细胞系ＳＷ１１１６生长的影响。方法设空白组、对照组、ＰＧ组、ＰＧｌ组、ＳＳ组、ＰＧｌ＋ＰＧ组和ＳＳ＋ＰＧ组。各组主要药物浓度分５×１０－５＿５×１０－１０ｍｏｌ／Ｌ６个浓度，联合用药组ＰＧ浓度均为５×１０－５ｍｏｌ／Ｌ。采用ＭＴＴ比色分析法检测细胞增殖情况。结果ＰＧ能提高细胞增殖率；ＰＧｌ则抑制细胞增殖；ＰＧ对ＰＧｌ的抑制率总体影响不大，而使其与ＰＧｌ浓度对数值呈显著负相关（ｒ＝－０．８３，Ｐ＜０．０５）。ＳＳ在低浓度时促进细胞增殖，而高浓度时则有抑制作用，细胞增殖率与药物浓度对数值呈显著负相关（ｒ＝－０．９１，Ｐ＜０．０５）；ＰＧ可逆转ＳＳ的促增殖作用，并使其抑制率有所提高，且细胞增殖率仍与ＳＳ浓度对数值呈显著负相关（ｒ＝－０．８４，Ｐ＜０．０５）。结论激素可控制大肠癌的生长，但尚有许多问题待阐明     

Effects of intra-gastric beta-casomorphin-7 on somatostatin and gastrin gene expression in rat gastric mucosa

AIM： To investigate the in vivo effect of beta-casomorphin-7on the regulation of gastric somatostatin and gastrin messenger RNA in rat gastric mucosa.
METHODS： Somatostatin and gastrin mRNA were quantified by RT-PCR and in situ hybridization （ISH）in 24 rats. The rats were divided into three treatment groups： basal diet ＋ physiological saline （n = 8）, basal diet ＋ beta-casomorphin-7 （7.5 × 10^-7 mol） （n = 8）,and basal diet ＋ poly-Gly-7 （containing equal mol of N with 7.5 × 10^-7 mol beta-casomorphin-7） （n = 8）.After oral administration for 30 days, rats were killed by exsanguinations.
RESULTS： After intra-gastric administration of betacasomorphin-7 for 30 d, gastrin mRNA increased by 52.8% （P 〈 0.05, n = 8）, and somatostatin mRNA levels decreased by 30.7% compared with the controls （P 〈0.01, n = 8）. No significant differences in the expression of the two genes were observed in the poly-Gly-treated group, although gastrin mRNA expression was elevated by 35.6% as against the control group （P = 0.15, n =8）. The long-term oral administration of a casomorphin solution significantly decreased the even gray of D-cells,but did not lower the number of D-cells both in the antrum and fundus. Interestingly, the number of G-cells increased in the antrum and fundus, but its average density was augmented only in the antrum.
CONCLUSION： Beta-casomorphin-7 is capable of modulating gene expression of the regulatory peptides from G and D cells. Data from in situ hybridization studies indicate that beta-casomorphin-7 affects gastrin gene expression indirectly by means of the paracrine action of somatostatin, and depends on its intrinsic molecular function.     

MEN1基因突变所致多内分泌腺瘤病1型二例及其家系研究

目的 探讨多内分泌腺瘤病1型的发病与MEN1基因突变的相互关系及其遗传特征。方法 从2个家系中的患者及其家庭成员抽提外周血淋巴细胞基因组DNA，运用PCR、DNA测序分析技术检测MEN1基因所有10个外显子，进一步用亚克隆测序鉴定其杂合性。结果发现两个家系中的先证者MENI基因均在第二号外显子存在杂合突变，分别为372-373insACCTGTCTATCATCGCCG和357-360delCTGT，前一种突变为一种新的突变类型。结论 在2个多内分泌腺瘤病1型中国人家系检出2种MEN1基因突变，其中MEN1基因372-373insACCTGTCTATCATCGCCG为一种新的MEN1基因突变。     

Effect of intragastric pH on antral gastrin and somatostatin release in anaesthetised, atropinised duodenal ulcer patients and controls.

The synchronous change in the antral release of gastrin and somatostatin into a vein draining the stomach was studied during acidic and alkaline intragastric pH in six anaesthetised duodenal ulcer patients and six controls after atropinisation. No differences in the basal secretion of gastrin and somatostatin were observed among the two groups. Alkaline as well as acidic intragastric pH had no effect on the antral release of somatostatin in duodenal ulcer patients and controls. In contrast, alkaline intragastric pH was associated with a significantly higher antral gastrin release in duodenal ulcer patients than in controls. Acidic intragastric pH was associated with a significantly smaller inhibition of antral gastrin release in duodenal ulcer patients than in controls. These results suggest that atropinised anaesthetised duodenal patients release gastrin abnormally in the presence of acidic or alkaline intragastric pH and that any inverse relationship between antral gastrin and somatostatin release is uncoupled under these conditions.     

Regulation of rat antral gastrin and somatostatin gene expression during starvation and after refeeding.

Antral gastrin and somatostatin gene expression during starvation and after refeeding with liquid meals of varying composition were studied. Northern and slot-blot hybridization analyses showed that starvation caused a marked decrease in antral gastrin messenger RNA (mRNA) level by 12 hours associated with an increase in somatostatin mRNA. After 48 hours of fasting, antral gastrin mRNA was 26% and somatostatin mRNA was 136% of their prefasting levels. Refeeding caused increased 2-hour integrated gastrin mRNA levels after liquid peptone (+45%), phenylalanine (+31%), and olive oil (+13%), but no changes were observed with glucose or saline solutions. Integrated 2-hour immunoreactive antral gastrin content was increased after peptone (+106%), phenylalanine (+68%), and olive oil (+32%) meals but was not increased after glucose (-11%) or saline (-10%). In some cases, both gastrin mRNA and peptide responses could be measured as early as 15 minutes. The same nutrients that increased gastrin mRNA levels caused decreased 2-hour integrated somatostatin mRNA levels; peptone (-30%), phenylalanine (-28%), and olive oil (-21%), but neither glucose nor saline, altered somatostatin mRNA levels. These results suggest that antral gastrin and somatostatin genes were regulated in opposite directions, in a coordinate manner, by specific gastric nutrients that stimulate gastrin release.     

大肠癌胃泌素、生长抑素的表达及比势与细胞周期调控基因的相关性

目的:探讨大肠癌组织中胃泌素(GAS)、生长抑素(SS)的表达及其比势与细胞周期调控蛋白P16~(INK4a)、P21~(CIP1)及细胞周期素(Cyclins)、细胞周期依赖性蛋白激酶(CDKs)表达的关系.方法:随机选择79例大肠癌患者的手术切除标本,采用免疫组化SP法检测GAS、SS、P16~(INK4a)、P21~(CIP1)、Cvclin D1、Cvclin E、Cyclin A、Cyclin B1、CDK2、CDK4的表达情况.结果:Cyclin D1、CDK2、CDK4、Cyclin A在GAS高表达组、中表达组的阳性表达率明显高于低表达组;而P16~(INK4a)、P21~(CIP1)阳性表达率与此相反.cyclin E在SS低表达组的阳性表达率明显高于中表达组、高表达组;P21~(CIP1)在ss高表达组、中表达组的阳性表达率明显高于低表达组;CDK2在SS低表达组的阳性表达率明显高于SS高表达组.大肠癌组织中GAS、SS表达的积分比值(GAS/SS)与Cyclin D1(r =0.252)、Cyclin E(r=0.387)、Cyclin A(r= 0.466)、CDK2(r=0.519)、CDK4(r=0.434)呈正相关(P<0.01)与P16~(INK4a)(r=-0.385)、P21~(CIP1)(r =-0.454)蛋白的表达积分呈负相关(P<0.01).结论:GAS、SS对大肠癌细胞生长的调控可能与P16~(INK4a)、P21~(CIP1)、Cvclin D1、Cvclin A、CDK2、CDK4、cvclin E基因异常表达有关.GAS对大肠癌细胞周期的调控位点可能在G1、S、G2期,SS对大肠癌细胞周期的调控位点可能在G1/S、G2/M期的交界点,即S、M期的入口.对大肠癌GAS/SS积分比值分析、可作为临床大肠癌生物学行为的重要评估指标.     

Localization of the MEN1 gene to a small region within chromosome 11q13 by deletion mapping in tumors.

The gene for multiple endocrine neoplasia type 1 (MEN1), an inherited predisposition to neuroendocrine neoplasm of the parathyroid glands, the pancreatic islet parenchyma, and the anterior pituitary gland, was recently mapped to chromosome 11q13 based on genetic linkage in families. We now show that the pathogenesis of MEN1-associated parathyroid lesions involves unmasking of a recessive mutation at the disease locus and that sporadic primary hyperparathyroidism shares the same mechanisms. By examination of allele losses in MEN1-associated lesions, we could define deletions of chromosome 11 and map the MEN1 locus to a small region within chromosome band 11q13, telomeric to the PYGM locus. In contrast, a low incidence of deletions involving the MEN1 gene was found in sporadic pituitary adenomas.     

Strategies for molecular intervention in esophageal cancers and their precursor lesions

Molecular analysis of malignant transformation in Barrett's epithelium provides insight into the temporal nature and significance of individual genetic events during multistep esophageal carcinogenesis. Potential targets for intervention in esophageal neoplasms include mutations involving retinoblastoma (Rb) and p53 tumor-suppressor pathways as well as tyrosine kinase cascades, which are known to promote cell cycle progression. Data from recent experiments provide the preclinical rationale for novel pharmacologic interventions in established esophageal cancers, and suggest strategies for chemoprevention in patients at risk for the development of these neoplasms.     

Different phenotypes of multiple endocrine neoplasia type 1 (MEN1) in monozygotic twins found in a Japanese MEN1 family with MEN1 gene mutation

We report monozygotic twins who showed different MEN1 phenotypes. The proband (28 y.o., female) had both primary hyperparathyroidism (PHP) and insulinoma, and genetic analysis revealed a point mutation (569del1, exon 3) of the MEN1 gene. This mutation causes a frameshift and produces a stop codon at codon 184. Restriction digestion (HinfI) analysis confirmed the same mutation of the MEN1 gene in six of the affected members including her two sisters, the monozygotic twins, and no such mutation in two unaffected members. In two generations of this family, eight of eleven family members had PHP and four of them were found to have other MEN1-related lesions. Both of the monozygotic twins had PHP. Interestingly, one had pancreatic tumor but the other had no evidence of it. Pituitary MRI showed no pituitary lesion in either of them. This is the first Japanese case of monozygotic twins with different MEN1 phenotypes.     

Participation of antral somatostatin in the local regulation of gastrin release

In anaesthetized pigs gastrin release was stimulated by irrigation of the antrum with bicarbonate and by instillation of a meat extract. The concentration of gastrin and somatostatin was measured by radioimmunoassay both in the antral and peripheral venous blood. The increase in gastrin was coupled to a significant decrease in somatostatin immunoreactivity as measured in the antral venous blood both during instillation of alkali and meat extract. In peripheral blood, the differences were much less evident and not statistically significant. It is speculated that the decrease in release of antral somatostatin during alkalinization and instillation of meat extract is the primary event which is followed by a diminished inhibition of gastrin liberation. Thus, the present data support the hypothesis that antral somatostatin participates in the local regulation of gastrin release.