myelin-basic-protein and Stomach-Neoplasms

Gastrin stimulates transcription of the human histidine decarboxylase (HDC) gene through binding to the G-protein-coupled cholecystokinin-B/gastrin receptor. We have explored the possibility that mitogen-activated protein kinase cascades play a role in mediating the effects of gastrin on transcription in a gastric cancer (AGS-B) cell line. Gastrin and phorbol 12-myristate 13-acetate (PMA) treatment of AGS-B cells was found to increase the phosphorylation of tyrosine residues of extracellular signal-regulated kinases (ERKs) 1 and 2 and increase ERK activity as determined by the in vitro phosphorylation of myelin basic protein. Reporter gene assays also demonstrated that gastrin and PMA stimulated Elk-1- and c-Myc-dependent transactivation, consistent with gastrin- and PMA-induced activation of ERKs. Overexpression of wild type ERK-1 and ERK-2 or activation of endogenous ERKs using activated MEK-1 (mitogen-activated protein kinase kinase or ERK kinase) overexpression stimulated HDC promoter activity in a dose-dependent fashion. Interruption of the ERK-related pathway using expression vectors for kinase-deficient ERKs or an ERK-specific phosphatase (PAC-1) blocked gastrin- and PMA-stimulated HDC promoter activity. In contrast, inhibition of the Jun kinase pathway using an interfering dominant negative SEK-1 (stress-activated protein kinase/ERK-1) mutant did not inhibit HDC promoter activity. Furthermore, whereas gastrin stimulated phosphorylation of Shc proteins and association with Grb2, activation of the HDC promoter was not influenced by expression of dominant negative Ras (N15 or N17) proteins. However, gastrin stimulated Raf-1 kinase activity, and activation of the HDC promoter was blocked by coexpression of a dominant negative Raf-1 construct. Overall, these data demonstrate that gastrin regulates HDC transcription in a Rafdependent, Ras-independent fashion predominantly through activation of the ERK-related pathway.

Topics: Base Sequence; Calcium-Calmodulin-Dependent Protein Kinases; Gastrins; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Genes, Reporter; Histidine Decarboxylase; Humans; JNK Mitogen-Activated Protein Kinases; Luciferases; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Myelin Basic Protein; Phosphorylation; Promoter Regions, Genetic; Recombinant Fusion Proteins; Signal Transduction; Stomach Neoplasms; Tetradecanoylphorbol Acetate; Transfection

The isoform of protein kinase C responsible for the inhibition of histamine-stimulated adenylate cyclase by the phorbol ester, 12-O-tetradecanoylphorbol 13-acetate (TPA), has been investigated in a particulate fraction prepared from the human gastric cancer cell line HGT-1. The alpha and epsilon isoforms of protein kinase C were detected in HGT-1 cells and in a 40,000 x g particulate fraction by immunoblotting procedures. The inhibitory effect of TPA on histamine-stimulated adenylate cyclase was enhanced by the presence of Ca2+, but decreased in a concentration-dependent manner by anti-peptide antibody to protein kinase C alpha, but not to protein kinase C epsilon. Addition of Ca2+ and TPA to the 40,000 x g particulate fraction stimulated the phosphorylation of the protein kinase C substrate myelin basic peptide 4-14. Protein kinase C alpha is probably the isoform responsible for inhibition of histamine-stimulated adenylate cyclase in HGT-1 cells.

Topics: Adenylyl Cyclase Inhibitors; Adenylyl Cyclases; Amino Acid Sequence; Calcium; Cell Fractionation; Dose-Response Relationship, Drug; Electrophoresis, Polyacrylamide Gel; Histamine; Humans; Immunoblotting; Isoenzymes; Molecular Sequence Data; Myelin Basic Protein; Phosphorylation; Protein Kinase C; Stomach Neoplasms; Tetradecanoylphorbol Acetate; Tumor Cells, Cultured

Topics: Actins; Adolescent; Adult; Aged; Antibodies, Monoclonal; Biomarkers, Tumor; Desmin; Female; Humans; Immunoenzyme Techniques; Keratins; Male; Middle Aged; Myelin Basic Protein; S100 Proteins; Stomach; Stomach Neoplasms; Vimentin

Tumors from two patients with carcinomatous neuropathy were studied with an immunohistochemical method using anti-myelin basic protein (anti-MBP) sera. In both cases, immunoreactive MBP was clearly demonstrated in some of the tumor cells, which were widely distributed either singly or, more often, in clusters. The staining intensity varied from cell to cell. An autoimmune mechanism to nervous elements has been suggested in the pathogenesis of carcinomatous neuropathy. MBP is known to be a highly specific and potent antigen that can induce allergic neuritis in animals. In one patient the progressively worsening neurologic condition rapidly improved after gastrectomy removed the carcinoma. It is possible that immunoreactive MBP in tumor cells may function as an "antigen" in the development of carcinomatous neuropathy.

Topics: ACTH Syndrome, Ectopic; Adenocarcinoma; Aged; Autoimmune Diseases; Humans; Lung Neoplasms; Male; Myelin Basic Protein; Neoplasm Proteins; Peripheral Nervous System Diseases; Stomach Neoplasms

Topics: Brain Neoplasms; Electrophoresis; Glioma; Humans; Lymphocytes; Macrophages; Myelin Basic Protein; Neoplasm Proteins; Stomach Neoplasms

Leukocyte migration tests under agarose (Clausen technique) were performed in 28 patients tentatively diagnosed as having any malignancy with the use of a 3 M KCl-extract panel prepared from bronchogenic, gastric, colonic, renal, and mammary carcinoma, corresponding normal tissues, carcinoembryonic antigen (CEA), and human encephalitogenic protein (HEP). 17 out of 22 proven carcinoma patients showed sensitization by reaction with optimal concentrated KCl-extract of cancer from the same organ type as their own tumor. In some cases positive reactions could be observed also with normal tissue antigen (NTA) of tumor organ type (7/22) or with an additional carcinoma extract of organ type differing from patients own primary tumor (8/22). Gastrointestinal carcinomas, especially, showed sensitization to CEA (7/12) contrary to nongastrointestinal carcinomas (1/10). With HEP no positive reactivity could be found (0/10). With the use of tumor antigen panel (5 antigens) only few positive reactions (MI less than 0.80 or greater than 1.20) could be observed in 6 patients with nonmalignant diseases (1/30 tests) and 8 healthy blood donors (1/40 tests). A widespread individual screening program using tissue antigens for patients suspected of malignancies could give a pattern of reactivities and improve the recognition of cell-mediated sensitization against tumor tissues.

Topics: Aged; Antigens, Neoplasm; Breast Neoplasms; Carcinoembryonic Antigen; Cell Migration Inhibition; Colonic Neoplasms; Epitopes; Female; Humans; Immunity, Cellular; Kidney Neoplasms; Leukocytes; Lung Neoplasms; Male; Middle Aged; Myelin Basic Protein; Neoplasms; Sepharose; Stomach Neoplasms

Topics: Antigens, Neoplasm; Cell Migration Inhibition; Humans; Isoantigens; Lymphocytes; Lymphokines; Macrophages; Myelin Basic Protein; Sarcoma; Stomach Neoplasms

The specific lymphocyte sensitization of patients with malignant diseases against a basic protein, isolated from human brain, was studied by the lymphocyte migration inhibition technique. A sensitization of lymphocytes of cancer patients against this encephalitogenic factor (EF) was first reported by FIELD and CASPARY in 1970. Their test system was the Macrophage-Electrophoretic-Mobility-Test (MEMT). In 17 out of 18 patients with malignant disease we found a specific inhibition or enhancement of the migration area of lymphocytes more than 15%.

Topics: Carcinoma, Bronchogenic; Cell Migration Inhibition; Humans; Intestinal Neoplasms; Lung Neoplasms; Lymphocyte Activation; Lymphoma; Macrophages; Male; Melanoma; Myelin Basic Protein; Neoplasms; Stomach Neoplasms

Topics: Adult; Aged; Aging; Animals; Antigens; Cell Migration Inhibition; Child; Child, Preschool; Female; Guinea Pigs; Humans; Immunity, Cellular; Lymphocytes; Macrophages; Male; Middle Aged; Myelin Basic Protein; Neoplasm Proteins; Stomach Neoplasms; Tuberculin