gastrin-17 and Disease-Models--Animal

Gastrin is known to enhance the growth of pancreatic carcinoma via the cholecystokinin (CCK)-2/gastrin receptor. We investigated the anti-tumor effect of Z-360 (calcium bis [(R)-(-)-3-[3-{5-cyclohexyl-1-(3,3-dimethyl-2-oxo-butyl)-2-oxo-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-3-yl}ureido]benzoate]), a novel orally active CCK-2 receptor antagonist alone or combined with the chemotherapeutic agent, gemcitabine in human pancreatic adenocarcinoma cell lines.. Z-360 potently inhibited specific binding of [3H]CCK-8 to the human CCK-2 receptor, with a Ki value of 0.47 nmol/l, and showed antagonistic activity for this receptor. The anti-tumor effect of Z-360 alone or combined with gemcitabine was assessed using subcutaneous xenografts of MiaPaCa2 and PANC-1 and an orthotopic xenograft model (PANC-1). Oral administration of Z-360 significantly inhibited the growth of MiaPaCa2 (41.7% inhibition at 100 mg/kg, P<0.01). Combined administration of Z-360 and gemcitabine significantly inhibited subcutaneous PANC-1 tumor growth compared with either agent alone (27.1% inhibition compared to effect with gemcitabine, P<0.05), and significantly prolonged survival compared with the vehicle control (median survival of 49 days in vehicle compared to 57 days in the combination group, P<0.05). In vitro studies showed that Z-360 significantly inhibited gastrin-induced proliferation of human CCK-2 receptor-expressing cells, and also significantly reduced gastrin-induced PKB/Akt phosphorylation to the level of untreated controls.. In the present study, we have shown that Z-360 combined with gemcitabine can inhibit pancreatic tumor growth and prolong survival in a pancreatic carcinoma xenograft model, on a possible mode of action being the inhibition of gastrin-induced PKB/Akt phosphorylation through blockade of the CCK-2 receptor. Our results suggest that Z-360 may be a useful adjunct to gemcitabine for the treatment of pancreatic carcinoma and a therapeutic option for patients with advanced pancreatic cancer.

Topics: Adenocarcinoma; Administration, Oral; Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Benzodiazepinones; Cell Line, Tumor; Cell Proliferation; Deoxycytidine; Disease Models, Animal; Female; Gastrins; Gemcitabine; Humans; Mice; Mice, Nude; Pancreatic Neoplasms; Phosphorylation; Proto-Oncogene Proteins c-akt; Receptor, Cholecystokinin B; Survival Rate; Xenograft Model Antitumor Assays

Gastrimmune is an immunogenic form of gastrin. It raises in situ antibodies against two proliferative forms of gastrin: amidated and glycine-extended gastrin-17. It has been shown to have a therapeutic action in several in vivo tumour models. Following immunization, due to the complex equilibrium that exists between the antibodies and gastrin, it is not technically feasible to assay for free gastrin.. To determine the effect of Gastrimmune-induced antigastrin antibodies on acid secretion.. A rat gastric fistula model was used. Animals (six per group) were immunized with a control immunogen or ascending doses of Gastrimmune. Acid output was measured following infusion of increasing doses of gastrin-17 and pentagastrin.. Gastrimmune-induced antibodies significantly reduced gastrin-17-stimulated acid output compared to control animals (Gastrimmune at 200 microg/rat vs. control; acid output following 30 ng gastrin-17, 0.01 vs. 0.16, P < 0.001; following 120 ng gastrin-17, 0.022 vs. 0.29, P < 0.001).. Gastrimmune significantly inhibits gastrin-17-stimulated acid output. This biological assay suggests that the antigastrin antibodies effectively bind gastrin-17. In addition to its use as an antineoplastic agent, Gastrimmune may have a role as an acid-decreasing agent in oesophagogastric pathology.

Topics: Animals; Antibodies; Cancer Vaccines; Diphtheria Toxoid; Disease Models, Animal; Female; Gastric Acid; Gastric Fistula; Gastrins; Gastrointestinal Agents; Immunization; Male; Pentagastrin; Rats; Rats, Wistar

Human astrocytic tumors grow into the normal brain parenchyma either as localized tumors, or as highly diffuse neoplasms. The diffuse phenotype relates to a specific sub-type of neoplastic astrocytes with a high motility and invasion capacity. Motility features refer to locomotion while invasion features refer to protease secretion. Our data reveal that several peptides belonging to the gastrin/cholecystokinin peptide class are able to significantly (and in certain cases very significantly) modify the level of tumor growth (at the level of cell proliferation and/or cell death), of motility and of invasion in various experimental models of human astrocytic tumors. We are synthesizing various gastrin/cholecystokinin-related peptides in order to develop clinical applications with which we want to inhibit astrocytic tumor growth, individual neoplastic astrocytic motility and the invasion of the normal brain parenchyma.

Topics: Animals; Astrocytoma; Biomarkers, Tumor; Brain Neoplasms; Disease Models, Animal; Drug Evaluation, Preclinical; Gastrins; Humans; Mice; Sincalide