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)

Kinins in the ascitic fluid from a patient with gastric cancer were purified by gel filtration and reversed-phase high-performance liquid chromatography (HPLC). Two fractions (fractions I and II) showed kinin activity. Fraction I did not correspond to either bradykinin or other known kinins, whereas fraction II corresponded to bradykinin. Fraction I contained 8 amino acid residues from bradykinin minus 1 proline plus 1 additional hydroxyproline. Sequence analysis of fraction I showed that the proline at the third amino acid residue of bradykinin was replaced by hydroxyproline. The retention time of fraction I on reversed-phase HPLC was exactly the same as that of synthetic [hydroxyprolyl3]bradykinin (Arg-Pro-Hyp-Gly-Phe-Ser-Pro-Phe-Arg) and was distinguishable from des-Pro3-bradykinin. Thus, these results demonstrate for the first time the presence of [hydroxyprolyl3]bradykinin in vivo. This is also the first report of the presence of bradykinin in human tumor ascites.
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PMID:Purification and identification of [hydroxyprolyl3]bradykinin in ascitic fluid from a patient with gastric cancer. 318 82

Three samples of 24-h urine were collected from each of 104 inhabitants of high-risk (Akita) and low-risk (Iwate) areas for stomach cancer in northern Japan, according to the following protocols: (i) when they were undosed, (ii) after ingestion of proline three times a day and (iii) after ingestion of proline together with vitamin C three times a day. These samples were analysed for N-nitrosamino acids, nitrate and chloride ion as indices of the exposure. The median values of N-nitrosoproline (NPRO) and N-nitroso-2-methylthiazolidine 4-carboxylic acid (NMTCA) excreted in the urine of undosed subjects were not different between the two areas; however, that of N-nitrosothiazolidine 4-carboxylic acid (NTCA) was significantly higher in subjects of the high-risk area. Salt intake, estimated from the level of chloride ion in the urine, did not differ in two areas. After intake of proline, the NPRO level increased significantly only in subjects of the high-risk area, but not in those of the low-risk area; intake of vitamin C inhibited this increase of NPRO and lowered the levels of other nitrosamino acids only in the high-risk subjects. In contrast, the urinary level of nitrate was higher in subjects of the low-risk area than in those of the high-risk area; nitrate levels were found to correlate well with the amounts of vegetables consumed.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Urinary excretion of N-nitrosamino acids and nitrate by inhabitants in high- and low-risk areas for stomach cancer in northern Japan. 367 30

Samples of 12-h overnight urine were collected from approximately 40 male adults in each of the 26 counties of China. Two urine specimens were collected from each subject--one after a loading dose of proline and ascorbic acid and another after a loading dose of proline only. Levels of N-nitrosamino acids, nitrite and nitrate were measured in urine samples and correlated with cancer mortality per 100,000 male subjects in the truncated age range 35-64 years. Preliminary results show no clear correlation between presence of stomach cancer or liver cancer and nitrosation potential [as measured by the urinary level of N-nitrosoproline (NPRO) after the proline load test or of nitrate]. There was a moderate, although not clearly significant, tendency for oesophageal cancer mortality rates to be associated positively with nitrosation potential and negatively with background ascorbate levels in plasma. This result was due chiefly to the inclusion of one county (Song Xian) in which there is a fairly high oesophageal mortality rate, an average nitrosation potential three times greater than that of any other county, and the lowest ascorbate index of any county. Further study of this county is planned.
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PMID:A correlation study on urinary excretion of N-nitroso compounds and cancer mortality in China: interim results. 367 31

The N-nitrosoproline (NPRO) test was used to study whether subjects with precancerous conditions of the stomach have an elevated potential for endogenous nitrosation. The highest yield of NPRO after ingestion of beetroot juice (as a source of nitrate) and proline was seen in subjects whose pH of fasting gastric juice was about 1.5-2. No increased level of NPRO was detected in subjects with more advanced lesions, compared to those with a normal stomach. Counts of total and nitrate-reducing bacteria were positively correlated with the pH of gastric juice but did not correlate with the urinary level of NPRO in the same individuals. Bacteria and intragastric nitrosation are discussed as possible etiological factors in human stomach cancer.
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PMID:Intragastric nitrosation and precancerous lesions of the gastrointestinal tract: testing of an etiological hypothesis. 367 33

Our previous study revealed that mutations of the p53 gene were detected by cDNA sequencing in one of four (25%) primary gastric tumors and in five of six (83%) gastric cancer cell lines. It was of interest that all five cell lines established from metastatic lesions had p53 gene mutations, while the single cell line established from a primary tumor lacked an abnormality. Thus, the current study was initiated to determine the frequency of p53 mutations in 10 pairs of samples from primary gastric carcinomas and their lymph node metastases, in addition to morphologically normal gastric mucosa. In addition, we correlated the findings with other relevant molecular markers including the metastasis associated nm23-H1 gene and loss of heterozygosity (LOH) using multiple polymorphic markers for chromosome 17p and sequencing the entire open reading frame (ORF) of the p53 gene. Five of ten (50%) patients were constitutionally heterozygous for one or more 17p and/or p53 probes (pYNZ 22, BamHI RFLP; pMct35.1, Mspl RFLP; php53cl, Bg/II RFLP), while none had LOH at the 17p and/or p53. A Bg/II RFLP for analysis of possible nm23-H1 somatic allelic deletion revealed no LOH out of four informative cases. One paired sample demonstrated the substitution of valine for isoleucine at codon 41 (GTT to ATT) in both primary gastric tumor and metastasis. Another metastatic sample demonstrated the substitution of proline for threonine at codon 278 (CCT to C/ACT) in addition to a non-mutated codon, while only the wild-type p53 sequence was present in the paired primary gastric tumor tissue.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Comparison of p53 gene mutations in paired primary and metastatic gastric tumor tissues. 790 5

Green tea extract (GTE) inhibits obviously gastrointestinal malignant tumors in rats induced by N-methyl-N'-nitro-n-nitrosoguanidine (MNNG). The incidence of tumor was 93.3% in the MNNG positive control group, whereas 53.3% in the MNNG plus GTE group (P < 0.01). The percentage of inhibiting tumor growth was 88% (P < 0.001). N-nitrosoproline blockage test in 3 groups of 45 cases of patients from the highly prone to (gastric cancer people), examined with gastroscope and classified pathologically, revealed that GTE can block N-nitroso-proline synthesis in vivo, with blockage rate of 91% in superficial chronic gastritis (P < 0.001), 94% in intestinal metaplasia (P < 0.001) and 93% in atypical hyperplasia and gastric cancer (P < 0.001). Chemical analysis demonstrated that the main ingredients in GTE are catechols (with the content of 50%), vitamins and trace elements. The mechanism of GTE's cancer-inhibiting and cancer-preventing function might be that catechols combine with N-nitroso-compounds or resolve them, and reduce their carcinogenic activity. These results will be of great significance in preventing gastrointestinal cancer.
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PMID:[The experiment of tumor-inhibiting effect of green tea extract in animal and human body]. 824 70

The hypothesis that intragastric synthesis of N-nitroso compounds (NOC) in early life could play a role in gastric carcinogenesis was tested by applying the N-nitrosoproline (NPRO) test to about 50 children living in high- and low-risk areas for stomach cancer in Costa Rica. The median values of excretion of NPRO and the sum of three nitrosamino acids (micrograms/12 h urine) were 10-20% of those in adults from other geographical high-risk areas for stomach cancer. The urinary NPRO level after proline intake was higher in children from the high-risk area (P < 0.04) and markedly reduced after ingestion of ascorbic acid together with proline (P < 0.05). NPRO levels on the day of proline intake were highly correlated with levels of nitrate excretion (P < 0.001). Mean levels of total NOC in an aqueous (pH 2) extract of cooked beans from the high- and low-risk areas were similar. Acid-catalyzed nitrosation of the extract increased the total NOC concentration up to 1000-fold, but there was no difference between samples from the two areas. About 10% of bean extracts from both areas showed weak direct-acting genotoxicity in Escherichia coli; after acid-catalyzed nitrosation, all samples were genotoxic at similar levels. The diet of children in the low-risk area satisfied recommended levels of intake of energy and most nutrients except riboflavin and retinol equivalents. Diets from the high-risk area were deficient in energy intake and all nutrients except protein and vitamin C.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:In vivo nitrosoproline formation and other risk factors in Costa Rican children from high- and low-risk areas for gastric cancer. 826 74

The effects of four fruit juices, processed vegetable juice, orange peel, green tea and low dose vitamin C on endogenous N-nitrosation in 86 subjects from a high-risk area for gastric cancer in Moping County, China were studied using urinary excretion of N-nitrosoproline (NPRO) as an indicator. After ingestion of 300 mg L-proline, urinary excretion of NPRO was significantly increased from a baseline of 2.5 +/- 1.6 micrograms/day to 8.7 +/- 6.2 micrograms/day. (P < 0.001). Vitamin C (75 mg) administration significantly reduced NPRO formation (62.3%, P < 0.002) although NPRO excretion remained higher than the baseline level (4.2 +/- 1.3 vs 2.2 +/- 1.2 micrograms/day, P < 0.001). Intake of fruit juices and green tea extracts (containing 75 mg vitamin C) or of orange peel powder (containing 3 mg vitamin C) together with 300 mg L-proline inhibited NPRO formation effectively to the baseline level or to levels significantly lower than the baseline level (P < 0.05-0.005). A processed juice of a number of vegetables (300 ml) significantly catalysed endogenous nitrosation (14.7 +/- 11.8 vs 9.4 +/- 4.7 micrograms/day, P < 0.05). Endogenous N-nitrosation was unaffected by the presence of intragastric lesions. The present study shows that endogenous nitrosation in this population is profoundly affected by environmental factors and that inhibitors, such as vitamin C, alpha-tocopherol and other non-nutritive compounds in the foods do inhibit endogenous nitrosation either synergistically or in an additive manner. The significance of fruits and vegetables in prevention of human cancers is discussed.
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PMID:Effects of fruit juices, processed vegetable juice, orange peel and green tea on endogenous formation of N-nitrosoproline in subjects from a high-risk area for gastric cancer in Moping County, China. 835 85

Helicobacter pylori can utilise amino acids as the sole carbon energy source. The present study demonstrated that H. pylori grown in continuous culture in a defined medium containing glucose and amino acids utilised alanine, arginine, asparagine, aspartate, glutamine, glutamate, proline and serine. Specific asparaginase and glutaminase enzymes deaminated asparagine and glutamine respectively to aspartate and glutamate, with the production of ammonia. The glutaminase activity was inhibited by 6-diazo-5-oxo-L-norleucine. All the 13 strains of H. pylori tested produced both glutaminase and asparaginase activities. Glutamine is important in the health of the gastric and intestinal mucosa and is a primary energy source for lymphocytes. Depletion of glutamine at the site of H. pylori infection may be of significance in the pathogenesis of H. pylori-associated diseases such as peptic ulcer and gastric cancer.
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PMID:Amino acid utilisation and deamination of glutamine and asparagine by Helicobacter pylori. 929 92

Cyclin-dependent kinase inhibitors (CDKI) are negative regulators of cell cycle progression by binding the cyclin-CDK complex and inhibiting the CDK activity. Genetic alteration in the CDKI genes has been implicated for carcinogenesis. To test the genetic alteration in the p27 and p57 genes, KIP family CDKI genes, 30 gastric tumor-normal pairs and 8 gastric cancer cell lines were analyzed for mutations by polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP). No mutation was detected in these genes although length polymorphisms in the proline-alanine repeat of the p57 gene were detected. When the p27 and p57 mRNAs were analyzed in gastric cancer cell lines by RT-PCR, the p27 mRNA was expressed considerably high in tumor cells but expression of the p57 mRNA was much low in gastric cancer cell lines compared to that of normal cells. The result suggests that inactivation of gene expression rather than mutations in the p57 gene accounts possibly for the involvement of this gene in tumorigenesis of gastric cancer. However, expression of the p27 gene seems to be essential for cell survival.
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PMID:Mutation and expression of the p27KIP1 and p57KIP2 genes in human gastric cancer. 1092 19


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