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)

A qualitative analysis of endogenous protein phosphorylation in microsomal fractions from surgical specimens of human gastric cancer, benign gastric ulcers and normal gastric tissues is presented. Fractions were incubated in the presence of (gamma-32P)ATP to measure the transfer of (gamma-32P) to natural substrates mediated by endogenous protein kinases. Phosphoproteins were characterized through PAGE-SDS and detected by autoradiography. KOH at high temperature was used to select for tyrosine-phosphorylated polypeptides on dried gels. We report a notorious enhancement in overall protein phosphorylation in gastric cancer samples over benign ulcers and normal controls as well. Moreover, a highly basic-low molecular weight phosphoprotein is found through 2-D protein gel analysis and a 50 kDa protein is detected only in the presence of Mg2+ after KOH treatment. These two proteins might become putative molecular markers to detect this type of neoplasia.
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PMID:Differential protein phosphorylation in human gastric adenocarcinomas. 180 88

Monoclonal antibody to rat liver cytochrome P-450 j isozyme, an activating enzyme specific to nitrosamine metabolism, was used in combination with immunoblotting, densitometer scanning of SDS-PAGE gels, and immunohistochemical staining, there was a trace of P-450 isozyme (Mr. 51. 5 kd) in human gastric mucosa with or without cancer. It was similar to P-450 j in molecular weight, catalysis and immunochemistry. We named it P-450 HSj isozyme. Both in 25 gastric cancer patients and 17 non-cancer patients, the concentrations (%) of P-450 HSj in the mucosa of the lesser curvature were higher than those of the greater curvature (P less than 0.01). This might be one of the important reasons why gastric carcinoma caused by nitrosamines is most common in the lesser curvature. The P-450 HSj was localized in the cytoplasm of some epithelial cells, especially in the glands with hyperplastic and intestinal metaplastic changes adjacent to carcinoma. It was also found in some normal glands and in tumor cells of highly differentiated adenocarcinoma, but not in tumor cells of lowly differentiated adenocarcinoma.
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PMID:[Immunochemical identification and localization of cytochrome P-45OHS; isozyme in human gastric mucosa and gastric carcinoma]. 263 18

NUGC4 cells derived from a human gastric cancer gave 6% Hanganutziu-Deicher (HD) antigen-positive cells by flow cytometric analysis using an affinity-purified chicken antibody to N-glycolyneuraminyl-lactosyl-ceramide (HD3 ganglioside). The cells showed no HD antigenic ganglioside by thin-layer chromatography enzyme-immunostaining; however, they were revealed to contain HD antigenic proteins with molecular masses of 150, 100, 90, 70, 65, 60, 47, and 40 kDa, by both immunoblotting after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoprecipitation of [35S]-methionine-labeled proteins, followed by SDS-PAGE and autoradiography. Neuraminidase treatment destroyed the antigenicity of all proteins, indicating that these molecules are glycoproteins and have N-glycolyneuraminic acid at the non-reducing terminal of carbohydrate chains as an HD antigenic epitope.
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PMID:Detection of glycoproteins as tumor-associated Hanganutziu-Deicher antigen in human gastric cancer cell line, NUGC4. 265 91

The nature of the antigen recognized by the murine monoclonal antibody A7 (Mab A7) against human colorectal carcinoma was investigated using immunochemical and biochemical techniques. Binding activity of 125I-labeled Mab A7 was examined using various human cancer cell lines. Mab A7 gave the highly specific binding to colon cancer cell lines, SW1116 and WiDr, and gave only a very weak or no reactivity to gastric cancer cell lines, pancreas cell lines or lung cancer cell lines. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting of the extractable antigen from SW1116 showed a single band at approximately 45,000 dalton formed by 125I-labeled Mab A7. Treatment of SW1116 with sodium periodate, pronase and ficin resulted in the loss of antigenic activity. These data strongly suggest that the antigen recognized by Mab A7 is composed of glycoprotein. Competitive binding analysis to the surface of the colon cancer cell line using polyclonal anti-CEA and Mab A7 as well as immunoblotting analysis using monoclonal anti-CEA and Mab A7 suggested that the antigen recognized by Mab A7 was different from CEA. Moreover, this antigen was also found in surgical specimens of colorectal cancer patients and its molecular property was identical to the antigen extracted from SW1116.
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PMID:Immunochemical characterization of the antigen recognized by the murine monoclonal antibody A7 against human colorectal cancer. 271 85

A high molecular weight, mucous glycoprotein (MG) from the pleural fluid of lung adenocarcinoma was purified by the DEAE-cellulose, gel-filtration and wheat germ agglutinin affinity chromatography. Protein portion of the molecule was composed of amino acids rich in serine, threonine and proline, but methionine and tyrosine concentrations were relatively low. About 65% of the weight, was composed of galactose, galactosamine, glucosamine, fucose and sialic acid. The gel-filtration pattern on Sepharose 4B revealed Mr greater than 10(6) Da. The SDS-PAGE pattern revealed a main band at the position of the Mr about 350 kDa under the reducing condition. Rabbit antibody against this molecule recognized mainly the peptide portion, and the radioimmunoassay (RIA) using the double antibody method was developed by this antibody. Serum MG level was low in healthy subjects and in benign diseases (0.8 +/- 0.7 U/ml; mean +/- SD and 1.1 +/- 2.3 U/ml, respectively). Thus, 3 U/ml was used as the cut-off value. The mean of serum MG levels and positive rates in malignant diseases were significantly high; 4.4 U/ml and 32.3% in lung cancer, 20.1 U/ml and 77.5% in pancreas cancer 11.6 U/ml and 64.3% in gastric cancer, 12.9 U/ml and 57.1% in hepatoma, 12.3 U/ml and 77.8 in colon cancer. Other malignancies such as ovarial and uterus cancer showed also high levels. Elevated values in these malignancies were observed frequently in patients with metastasis. On the other hand, the false positive cases were found in 10% of benign diseases. Determination of MG seems to be useful for the detection of several kinds of malignancies, but it is not adequately sensitive as a screening method for early cancer detection.
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PMID:Clinical significance of mucin-like high molecular weight glycoprotein originated from lung cancer as tumor marker. 274 68

In human antral membranes, VIP and its natural analogs inhibited the binding of HPLC-purified 125I-VIP, according to the following order of potency: VIP greater than rh GRF greater than helodermin greater than r PHI greater than PHM greater than p PHI greater than hp GRF greater than h, p secretin. No specific binding was detected in plasma membranes purified from the human fundus. In human antral membranes, Scatchard plots were compatible with the existence of two classes of VIP receptors, the first class with high affinity and low binding capacity (Kd = 0.1 nM, Bmax = 10 fmol/mg protein) and another class with a low affinity and higher binding capacity (Kd = 12) nM, Bmax = 1,000 fmol/mg protein). The structure of the VIP receptor in purified plasma membranes prepared from human antral glands and from the HGT-1 human gastric cancer cells was subsequently probed using the cross-linking reagent DSP and 125I-VIP. In agreement with the pharmacological study and the Scatchard analysis of the binding data, SDS gel electrophoresis of the solubilized receptor identified two radiolabeled peptides Mr 67,000 and 34,000 containing disulfide bonds. According to its sensitivity to low doses of VIP and to GTP, the Mr 67,000 binding site represents the membrane domains involved in the physiologial regulation of adenylate cyclase by VIP in normal and transformed human gastric epithelia.
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PMID:Pharmacology and molecular identification of vasoactive intestinal peptide (VIP) receptors in normal and cancerous gastric mucosa in man. 283 6

Ascitic fluid from tumour patients (hepatoma, gastric cancer, gallbladder cancer, colorectal cancer, ovarian cancer) and from non-malignant diseases (liver cirrhosis, congestive heart failure) were compared with respect to their content of determinants of the fibrinolytic system, tissue-type plasminogen activator antigen (t-PAag) and activity (t-PAact), urokinase-type plasminogen activator antigen (u-PA) and plasminogen activator inhibitor activity (PAI). Furthermore, SDS-polyacrylamide slab-gel electrophoresis (SDS-PAGE) was performed to evaluate molecular weight distribution of the detectable fibrinolytic parameters. In malignant ascites, PAI activity was three to four times higher, and increased complex formation of PAI with t-PA could be demonstrated, compared with non-malignant ascitic fluid. Tissue-type plasminogen activator antigen and activity showed a similar concentration in ascites of both study groups. Urokinase-type plasminogen activator antigen was detectable neither in ascites of malignant nor in ascites of non-malignant origin. It is concluded that t-PA is the physiological plasminogen activator in ascites and that increased PAI levels followed by increased complex formation between t-PA and PAI might reflect a reaction of the peritoneum.
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PMID:Plasminogen activators and plasminogen activator inhibitor in malignant and non-malignant ascitic fluid. 285 12

A new mouse monoclonal antibody 9A3 (IgGl,K) raised against human poorly differentiated gastric adenocarcinoma cell line TMK-1 was produced. Immunohistochemically, 9A3 antibody reacted strongly with gastric carcinoma, colon carcinoma, pancreas carcinoma, lung carcinoma, breast carcinoma and cervical carcinoma of the uterus. This antibody did not react with various normal tissues from the whole body with the exception of neutrophils and macrophages. In fetal tissues, 9A3 antibody reacted with esophageal mucosa and colon epithelium, but did not react with purified carcinoembryonic antigen (CEA). The molecular weight of the antigen extracted with NP-40 from TMK-1 cells was estimated to be about 46,000 daltons by SDS-PAGE. The 9A3 antigen was also detected in conditioned tissue culture medium of the TMK-1 cell line and sera of gastric cancer patients and tumor imaging could be performed in xenotransplantable human gastric carcinoma in nude mice. In summary, 9A3 antibody may serve as a new marker for detection of cancer by immunohistochemical, cytological techniques and serologically in the sera of cancer patients.
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PMID:[Monoclonal antibody 9A3 raised against a human poorly differentiated gastric adenocarcinoma cell line]. 372 60

Six monoclonal antibodies reacted with different cancer-associated antigens were studied. In which, CL-2 reacts with carcinoembryonic antigen (CEA), CL-3: CEA and S-Tn, CL-4: glycosphingolipid, PS-7: S-Tn. PS-10: S-Tn Tn, and glycosphingolipid, all weakly, and GS-2: CEA, Tn, S-Tn, glycolipid, all strongly. All of the monoclonal antibodies expressed strongly in gastric cancer tissues, the positive rate are 62%-91.6%, but none are expressed in normal gastric tissues, except PS-7 (35% weakly expressed). The cancer-associated antigens in gastric juice, serum and feces were detected by binding inhibition ELISA and SDS-PAGE; Western blot methods. The results showed that: (1) The positive rates in gastric cancer are all over 90%, when detected by cock-tail monoclonal antibodies of any three. The false positive rates are 8%- 14%. (2) Detection of cancer-associated antigens in gastric juice and feces gives higher positive rates than in serum, it shows the carbohydrate antigens is relatively more stable than the protein when it passes through the gastrointestinal canal. (3) The monoclonal antibodies against S-Tn, Tn, and glycosphingolipid antigens are good markers for the diagnosis of gastric cancer.
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PMID:[Characterization and detection of cancer-associated antigens in patients with gastric cancer]. 750 52

This study examined the expression of receptors of the bombesin (BBS) family in human gastric-cancer cell lines. Of 5 cell lines screened, only one, St42, demonstrated specific binding sites for 125I-Tyr4-BBS, which have been further characterized. This binding was saturable, and temperature- and time-dependent. Scatchard analysis of displacement data performed at 37 degrees C revealed 2 binding sites: a high-affinity, low-capacity site (KD = 0.13 nM, Bmax = 1500 sites/cell) and a lower-affinity, higher-capacity site (KD = 11 nM, Bmax = 35,000 sites/cell); the latter was lost when internalization of peptide was prevented, suggesting that it may be an artefact. Displacement assays with gastrin-releasing peptide (GRP) and neuromedin B (NMB) revealed that the receptor was of the GRP-preferring sub-type (GRP IC50 = 0.35 nM; NMB IC50 = 112 nM). Co-valent cross-linking of 125I-Tyr4-BBS to the receptor demonstrated the presence of a single band corresponding to a molecular weight of 37 to 44 kDa on SDS-PAGE, similar to that of the cloned GRP receptor protein core. G-protein linkage of this receptor was demonstrated by selective inhibition of 125I-Tyr4-BBS binding by guanosine nucleotides. The binding of BBS to the receptor resulted in a rise in intracellular calcium. Three of four structurally distinct BBS antagonists bound to the receptor with high affinity, but [DPhe12, Leu14]-bombesin did not cause any displacement of 125I-Tyr4-BBS even at 10 mM. The functional significance of GRP receptors on human gastric-cancer cells is as yet unknown, but further studies may determine whether such receptors have importance in the therapy of gastric cancer.
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PMID:Characterization of a bombesin/gastrin-releasing peptide receptor on a human gastric-cancer cell line. 819 83


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