cyclic-gmp and Adenocarcinoma

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Apoptosis; Caspase 3; Cell Line, Tumor; Colonic Neoplasms; Cyclic GMP; Cyclic Nucleotide Phosphodiesterases, Type 5; Drug Resistance, Neoplasm; Drug Synergism; Drugs, Chinese Herbal; Humans; Hypoxia; Male; Mice, Inbred BALB C; Nitroso Compounds; Oxadiazoles; Oxazines; Phosphodiesterase 5 Inhibitors; Plant Extracts; Reactive Oxygen Species; Serum Albumin, Human; Soluble Guanylyl Cyclase; Vardenafil Dihydrochloride

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal types of cancer and the 5-year survival rate is only 5%. Several studies have suggested that cancer stem cells (CSCs) are thought to be involved in recurrence and metastasis and so it is essential to establish an approach targeting CSCs. Here we have demonstrated that cyclic guanosine monophosphate (cGMP) suppressed CD44 expression and the properties of CSCs in PDAC. Microarray analysis suggested that cGMP inhibited Forkhead box O3 (FOXO3), which is known as a tumor suppressor. Surprisingly, our data demonstrated that FOXO3 is essential for CD44 expression and the properties of CSCs. Our data also indicated that patients with high FOXO3 activation signatures had poor prognoses. This evidence suggested that cGMP induction and FOXO3 inhibition could be ideal candidates for pancreatic CSC.

Topics: Adenocarcinoma; Animals; Biomarkers, Tumor; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cyclic GMP; Forkhead Box Protein O3; Gene Expression Regulation, Neoplastic; Humans; Hyaluronan Receptors; Mice; Microarray Analysis; Neoplasm Metastasis; Neoplastic Stem Cells; Prognosis; Xenograft Model Antitumor Assays

cAMP and cGMP signaling is important both for normal and cancer cells. This signaling is controlled by adenylyl and guanylyl cyclases and cyclic nucleotide phosphodiesterases. One of the direct targets for cGMP is protein kinase G (PKG). The main aim of this work was to investigate cGMP and PKG signaling in pancreatic adenocarcinoma (PDAC) cells.. The PKG activity, cGMP, and calcium level were measured with the CycLex Cyclic GMP dependent protein kinase (cGK) Assay Kit, the DetectX Cyclic GMP Colorimetric EIA Kit, and the Fluo-4 NW Calcium Assay Kit, respectively. The Proteome Profiler Array was done using Human Phospho-Kinase Array and Human Phospho-MAPK Array Kits.. This study shows for the first time that functional PKG1 is expressed in PDAC cells. It demonstrates that the specific PKG1 inhibitor, DT3, induces cytotoxicity through necrosis and reduces proliferation and migration of PDAC cells. Moreover, ERK1/2 and p38 can be considered as potential targets for PKG1 in PDAC cells. In addition, the study shows that phosphodiesterases and nitric oxide-guanylyl cyclases regulate the cGMP level in PDAC cells, affecting the proliferation of the cells.. The cGMP and PKG signaling may be a target for developing new therapeutic approaches for PDAC.

Topics: Adenocarcinoma; Apoptosis; Blotting, Western; Calcium; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Cyclic GMP; Cyclic GMP-Dependent Protein Kinases; Gene Expression Regulation, Neoplastic; Guanylate Cyclase; Humans; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Nitric Oxide; p38 Mitogen-Activated Protein Kinases; Pancreatic Neoplasms; Peptides; Phosphoric Diester Hydrolases; Phosphorylation; Protein Kinase Inhibitors; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction

The natural hormone uroguanylin regulates intestinal fluid homeostasis and bowel function through activation of guanylate cyclase-C (GC-C), resulting in increased intracellular cyclic guanosine-3',5'-monophosphate (cGMP). We report the effects of uroguanylin-mediated activation of the GC-C/cGMP pathway in vitro on extracellular cGMP transport and in vivo in rat models of inflammation- and stress-induced visceral hypersensitivity. In vitro exposure of intestinal Caco-2 cells to uroguanylin stimulated bidirectional, active extracellular transport of cGMP into luminal and basolateral spaces. cGMP transport was significantly and concentration dependently decreased by probenecid, an inhibitor of cGMP efflux pumps. In ex vivo Ussing chamber assays, uroguanylin stimulated cGMP secretion from the basolateral side of rat colonic epithelium into the submucosal space. In a rat model of trinitrobenzene sulfonic acid (TNBS)-induced visceral hypersensitivity, orally administered uroguanylin increased colonic thresholds required to elicit abdominal contractions in response to colorectal distension (CRD). Oral administration of cGMP mimicked the antihyperalgesic effects of uroguanylin, significantly decreasing TNBS- and restraint stress-induced visceromotor response to graded CRD in rats. The antihyperalgesic effects of cGMP were not associated with increased colonic spasmolytic activity, but were linked to significantly decreased firing rates of TNBS-sensitized colonic afferents in rats in response to mechanical stimuli. In conclusion, these data suggest that the continuous activation of the GC-C/cGMP pathway along the intestinal tract by the endogenous hormones guanylin and uroguanylin results in significant reduction of gastrointestinal pain. Extracellular cGMP produced on activation of GC-C is the primary mediator in this process via modulation of sensory afferent activity.

Topics: Acetylcholine; Acetylglucosamine; Adenocarcinoma; Animals; Cell Differentiation; Cell Line, Tumor; Colitis; Colon; Colorectal Neoplasms; Cyclic GMP; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Electric Stimulation; Female; Gastrointestinal Diseases; Gene Expression Regulation, Neoplastic; Guanylate Cyclase; Humans; Hyperalgesia; Intestinal Mucosa; Male; Mast Cells; Morphine; Multidrug Resistance-Associated Proteins; Natriuretic Peptides; Organic Anion Transporters, Sodium-Independent; Peroxidase; Rats; Rats, Sprague-Dawley; Rats, Wistar; Restraint, Physical; RNA, Messenger; Signal Transduction; Trinitrobenzenesulfonic Acid; Visceral Pain

Nitric oxide (NO), an uncharged free radical is implicated in various physiological and pathological processes. The present study is an investigation on the effect of NO on proliferation, apoptosis and migration of colon cancer cells. Colon adenocarcinoma cells, WiDr, were used for the in vitro experiments. Tissues from colon adenocarcinoma, adjacent normal and inflammatory tissue and lymph node with metastasis were evaluated for iNOS, MMP-2/9 and Fra-1/Fra-2. NO increases the proliferation of cancer cells and simultaneously prevents apoptosis. Expression of MMP-2/9, RhoB and Rac-1 was enhanced by NO in a time dependent manner. Further, NO increased phosphorylation of ERK1/2 and induced nuclear translocation of Fra-1 and Fra-2. Electrophoretic mobility shift analysis and use of deletion mutant promoter constructs identified role of AP-1 in NO-mediated regulation of MMP-2/9. iNOS, MMP-2/9, Fra-1 and Fra-2 in normal and colon adenocarcinoma tissues were analyzed and it was found that increased expression of these proteins in cancer when compared to normal provides support to our in vitro findings. The study showed that the NO-cGMP-PKG promotes MMP-2/9 expression by activating ERK-1/2 and AP-1. This study reveals the insidious role of NO in imparting tumor aggressiveness.

Topics: Adenocarcinoma; Blotting, Western; Cell Adhesion; Cell Line, Tumor; Cell Movement; Cell Proliferation; Colonic Neoplasms; Cyclic GMP; Cyclic GMP-Dependent Protein Kinases; Electrophoretic Mobility Shift Assay; Enzyme-Linked Immunosorbent Assay; Humans; MAP Kinase Signaling System; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Nitric Oxide; Phosphorylation; Real-Time Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Up-Regulation

Tumor cell migration is considered as a major event in the metastatic cascade. Here we examined the effect of grape seed proanthocyanidins (GSPs) on migration capacity and signaling mechanisms using nonsmall cell human lung cancer cells. Using in vitro migration assay, we found that treatment of A549 and H1299 cells with GSPs resulted in concentration-dependent inhibition of migration of these cells. The migration capacity of cells was reduced in presence of N(G)-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase. GSPs suppressed the elevated levels of endogenous NO/NOS in A549 and H1299 cells and blocked the migration promoting capacity of L-arginine. Treatment with guanylate cyclase (GC) inhibitor 1-H-[1,2,4]oxadiaxolo[4,3-a]quinolalin-1-one (ODQ) reduced the migration of A549 cells whereas additional presence of 8-bromoguanosine 3'5'-cyclic monophosphate (8-Br-cGMP, cGMP analogue) restored the migration of these cells, suggesting a role for GC in migration of A549 cells. GSPs reduced the elevated levels of cGMP in cancer cells and also blocked the migration restoring activity of 8-Br-cGMP. The mitogen-activated protein kinase kinase (MAPKK) inhibitor, UO126, inhibited the migration of A549 cells, indicating a role for MAPKK in the migration. Additionally, UO126 and ODQ inhibited the migration restoring effects of L-arginine in L-NAME-treated cells, suggesting the involvement of cGMP and MAPK pathways in NO-mediated migration. GSPs inhibited L-arginine and 8-Br-cGMP-induced activation of ERK1/2 in A549 cells. Together, these results indicate sequential inhibition of NO/NOS, GC, and MAPK pathways by GSPs in mediating the inhibitory signals for cell migration, an essential step in invasion and metastasis.

Topics: Adenocarcinoma; Blotting, Western; Carcinoma, Large Cell; Carcinoma, Non-Small-Cell Lung; Cell Movement; Cell Proliferation; Cell Survival; Cyclic GMP; Enzyme Inhibitors; Fluorescent Antibody Technique; Grape Seed Extract; Guanylate Cyclase; Humans; Lung Neoplasms; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase; Oxadiazoles; Plant Extracts; Proanthocyanidins; Quinoxalines; Receptors, Cell Surface; Signal Transduction; Tumor Cells, Cultured; Vitis

Vessel dilator and kaliuretic peptide have anticancer effects in human prostate adenocarcinomas.. The effects of vessel dilator, kaliuretic peptide and cyclic GMP on Ras were examined in human prostate adenocarcinoma cells.. Vessel dilator and kaliuretic peptide decreased the activation of Ras -GTP over a concentration range of 0.01 microM to 1 microM. Vessel dilator and kaliuretic peptide (each 1 muM) inhibited the phosphorylation of Ras by 95% (p<0.0001) and 90% (p<0.0001), respectively. At 0.01 microM of kaliuretic peptide, the maximal inhibition was 95% . The inhibition of Ras lasted for 48 to 72 hours secondary to both peptides. Their ability to inhibit Ras was inhibited by cyclic GMP antibody and cyclic GMP itself inhibited Ras phosphorylation (89%; p=0.0015).. Vessel dilator and kaliuretic peptide both inhibit Ras partially mediated via cyclic GMP as part of their anticancer mechanism(s) of action.

Topics: Adenocarcinoma; Aged; Atrial Natriuretic Factor; Cyclic GMP; Guanosine 5'-O-(3-Thiotriphosphate); Guanosine Diphosphate; Humans; Immunoblotting; Male; Natriuresis; Peptide Fragments; Prostatic Neoplasms; Protein Precursors; ras Proteins; Sodium-Potassium-Exchanging ATPase; Tumor Cells, Cultured

Atrial natriuretic peptide and long-acting natriuretic peptide have anticancer effects in human prostate adenocarcinoma.. The effects of atrial natriuretic peptide and long-acting natriuretic peptide and cyclic GMP on Ras were examined in human prostate adenocarcinoma cells.. Atrial natriuretic peptide and long-acting natriuretic peptide reduced the activation of Ras-GTP over a concentration range of 0.01 microM to 1 microM. Atrial natriuretic peptide and long-acting natriuretic peptide (each 0.1 microM) inhibited the phosphorylation of Ras 90% (p<0.0001) and 83% (p<0.0001), respectively. At 0.01 microM of long-acting natriuretic peptide, the maximal inhibition was 89%, which occurred within 5 minutes. Both peptide hormones inhibited Ras for 24 hours. Their ability to inhibit Ras was inhibited by cyclic GMP antibody and cyclic GMP itself inhibited Ras phosphorylation (72%; p=0.009).. Atrial natriuretic peptide and long-acting natriuretic peptide both inhibit Ras partially mediated via cyclic GMP as part of their anticancer mechanism(s) of action.

Topics: Adenocarcinoma; Aged; Atrial Natriuretic Factor; Blotting, Western; Cyclic GMP; Humans; Immunoblotting; Immunoprecipitation; Male; Peptide Fragments; Phosphorylation; Prostatic Neoplasms; ras Proteins

Mortality from colon cancer is significant with an expected 30,350 colon cancer deaths in 2005 with current treatment(s). Long-acting natriuretic peptide, vessel dilator, kaliuretic peptide, and atrial natriuretic peptide have significant anticancer effects in breast and pancreatic adenocarcinomas.. Whether these peptide hormones have anticancer effects in colon adenocarcinoma cells and whether these effects are specifically mediated by cyclic GMP has not been determined.. These peptide hormones were evaluated for anticancer effects in human colon adenocarcinoma cells and to determine whether their anticancer effects are specifically mediated by cyclic GMP.. There was a 89-97% decrease (p <0.001 for each) in colon adenocarcinoma cells within 24 h with 1 mM of these peptide hormones. There was a significant (p <0.05) decrease in human colon cancer cell number with each 10-fold increase in concentration from 1 to 1,000 microM (i.e., 1 mM) of these four peptide hormones without any proliferation in the 3 d following this decrease. These same hormones decreased DNA synthesis 65-83% (p <0.001). Cyclic GMP antibody inhibited 75- 80% of these peptides' ability to decrease colon adenocarcinoma cell number and inhibited 92-96% of their DNA synthesis effects and 97% of cyclic GMP's effects. Western blots revealed that for the first time natriuretic peptide receptors (NPR) A and C were present in colon adenocarcinoma cells.. Four peptide hormones eliminate up to 97% of colon cancer cells within 24 h with their DNA effects specifically mediated by cyclic GMP.

Topics: Adenocarcinoma; Atrial Natriuretic Factor; Cell Count; Cell Line, Tumor; Cell Proliferation; Cells, Cultured; Colonic Neoplasms; Cyclic GMP; DNA, Neoplasm; Dose-Response Relationship, Drug; Humans; Natriuretic Peptides; Peptide Fragments; Protein Precursors

Long-acting natriuretic peptide, vessel dilator, kaliuretic peptide and atrial natriuretic peptide are four peptide hormones synthesized by the same gene. Their main known biologic properties are sodium and water excretion and blood pressure lowering in both animals and humans.. These four peptide hormones, each at their 1-microm concentrations, were evaluated for their ability to decrease the number and/or proliferation of human pancreatic adenocarcinoma cells in culture at 24, 48, 72 and 96 h.. Vessel dilator, long-acting natriuretic peptide, kaliuretic peptide and atrial natriuretic peptide decreased the number of human pancreatic adenocarcinoma cells in culture by 65% (P<0.001), 47% (P<0.01), 37% (P<0.05) and 34% (P<0.05), respectively, within 24 h. This decrease was sustained without any proliferation of the cancer cells occurring in the 3 days following this decrease in number. The mechanism of these peptide hormones' decrease in cancer cell number and antiproliferative effects was a 83% (P<0.001) or greater inhibition of DNA synthesis but not owing to enhanced apoptosis, i.e. programmed cell death. The two known mediators of these peptide hormones' mechanism(s) of action, i.e. cyclic GMP and prostaglandin E2, inhibited DNA synthesis in these adenocarcinoma cells by 51% and 23%, respectively.. Four peptide hormones significantly decrease the number of pancreatic adenocarcinoma cells within 24 h and inhibit the proliferation of these cells for at least 96 h. Their mechanism of doing so is via inhibition of DNA synthesis mediated in part by cyclic GMP.

Topics: Adenocarcinoma; Apoptosis; Atrial Natriuretic Factor; Cell Division; Cyclic GMP; Dinoprostone; DNA, Neoplasm; Dose-Response Relationship, Drug; Humans; Pancreatic Neoplasms; Peptide Fragments; Protein Precursors; Tumor Cells, Cultured

The enteric peptides, guanylin and uroguanylin, are local regulators of intestinal secretion by activation of receptor-guanylate cyclase (R-GC) signaling molecules that produce cyclic GMP (cGMP) and stimulate the cystic fibrosis transmembrane conductance regulator-dependent secretion of Cl- and HCO3-. Our experiments demonstrate that mRNA transcripts for guanylin and uroguanylin are markedly reduced in colon polyps and adenocarcinomas. In contrast, a specific uroguanylin-R-GC, R-GCC, is expressed in polyps and adenocarcinomas at levels comparable with normal colon mucosa. Activation of R-GCC by uroguanylin in vitro inhibits the proliferation of T84 colon cells and elicits profound apoptosis in human colon cancer cells, T84. Therefore, down-regulation of gene expression and loss of the peptides may interfere with renewal and/or removal of the epithelial cells resulting in the formation of polyps, which can progress to malignant cancers of the colon and rectum. Oral replacement therapy with human uroguanylin was used to evaluate its effects on the formation of intestinal polyps in the Min/+ mouse model for colorectal cancer. Uroguanylin significantly reduces the number of polyps found in the intestine of Min/+ mice by approximately 50% of control. Our findings suggest that uroguanylin and guanylin regulate the turnover of epithelial cells within the intestinal mucosa via activation of a cGMP signaling mechanism that elicits apoptosis of target enterocytes. The intestinal R-GC signaling molecules for guanylin regulatory peptides are promising targets for prevention and/or therapeutic treatment of intestinal polyps and cancers by oral administration of human uroguanylin.

Topics: Adenocarcinoma; Adenomatous Polyposis Coli; Aged; Aged, 80 and over; Amino Acid Sequence; Animals; Apoptosis; Caco-2 Cells; Colonic Neoplasms; Cyclic GMP; Down-Regulation; Female; Gastrointestinal Hormones; Gene Expression Regulation, Neoplastic; Humans; Male; Mice; Mice, Inbred C57BL; Middle Aged; Molecular Sequence Data; Natriuretic Peptides; Peptides; Receptors, Cell Surface; RNA, Messenger; Tumor Cells, Cultured

Although in vitro studies have suggested that Helicobacter pylori not only attaches to cultured cells but also induces signal transduction events in host cells, the underlying mechanism of H. pylori action has yet to be fully investigated. In the present study, a cytotoxin-positive H. pylori was used to infect and examined for its effect on the stimulation of second messengers in human gastric adenocarcinoma (AGS). Results showed that H. pylori increased cytosolic free calcium concentration [Ca2+]i in host cells in a dose-dependent manner. The increase of [Ca2+]i was due to release from the intracellular Ca2+ store as well as entry to the extracellular Ca2+. H. pylori infection on host cells was also found to induce the generations of inositol phosphates, adenosine 3', 5'-cyclic monophosphate, and guanosine 3',5'-cyclic monophosphate, and to stimulate the secretion of pepsinogen.

Topics: Adenocarcinoma; Calcium; Calcium Signaling; Cyclic AMP; Cyclic GMP; Cytosol; Helicobacter Infections; Helicobacter pylori; Humans; Inositol Phosphates; Pepsinogen A; Signal Transduction; Stomach Neoplasms; Tumor Cells, Cultured

Human colonic adenocarcinoma cell lines have conserved several features of the native tissue. Among these is the expression of cell surface receptors for hormones and neurotransmitters that may be involved in the regulation of proliferation and differentiation processes in these cancer cells. Here, we confirm that high-affinity binding sites for the Vasoactive Intestinal Polypeptide (VIP) and for the VIP analogue Pituitary Adenylate-Cyclase Activating Polypeptide (PACAP), were expressed in 4 human colonic adenocarcinoma cell lines, HT29, SW403, DLD-1 and Caco-2, that spontaneously displayed variable phenotypic properties in culture. We demonstrated that after long-term treatments, VIP and PACAP significantly reduced cell proliferation in the 4 cell lines and modulated intracellular cAMP and cGMP levels. Furthermore, conspicuous differences were observed from one cell type to another concerning expression of the receptor subsets or the effects of the neuropeptides on cell growth and on cyclic nucleotides production.

Topics: Adenocarcinoma; Caco-2 Cells; Cell Division; Colonic Neoplasms; Cyclic AMP; Cyclic GMP; Growth Inhibitors; HT29 Cells; Humans; Neuropeptides; Pituitary Adenylate Cyclase-Activating Polypeptide; Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; Receptors, Pituitary Hormone; Receptors, Vasoactive Intestinal Peptide; Tumor Cells, Cultured; Vasoactive Intestinal Peptide

To test the hypothesis that neural mechanisms evoked by unilateral pulmonary artery occlusion (UPAO) affect the release of atrial natriuretic peptides (ANP) from the heart, hemodynamics and levels of plasma ANP and cyclic guanosine monophosphate (c-GMP) were studied in 11 patients with lung cancer. The UPAO induced a significant rise in heart rate by 5.3 percent, increased mean pulmonary artery pressure by 31 percent without affecting right atrial pressure, and decreased plasma ANP levels in the coronary sinus by 17.4 percent (p < 0.05) from 202.5 +/- 27.1 pg/ml to 167.2 +/- 27.4 pg/ml. Atropine sulfate (0.04 mg/kg) injection increased the heart rate by 38.2 percent (p < 0.01), reduced the stroke volume index by 25.1 percent, decreased coronary sinus ANP levels from 198.5 +/- 16.4 pg/ml to 124.8 +/- 19.6 pg/ml (p < 0.01), and decreased coronary sinus plasma c-GMP levels from 4.6 +/- 0.5 pmol/ml to 3.1 +/- 0.4 pmol/ml (p < 0.05). After atropine pretreatment, UPAO induced a significant (p < 0.05) increase of 34.8 percent in the coronary sinus ANP level. Thus, it is concluded that in UPAO, the secretion of ANP from the heart is modulated partly by the autonomic nervous system.

Topics: Adenocarcinoma; Aged; Atrial Natriuretic Factor; Atropine; Carcinoma, Squamous Cell; Catheterization, Peripheral; Cyclic GMP; Female; Heart; Hemodynamics; Humans; Lung Neoplasms; Male; Middle Aged; Pulmonary Artery; Time Factors

Flavonoids, compounds containing a 2-phenylbenzo(gamma)pyrane nucleus, are universally distributed among vascular plants. Even though flavonoids are ingested in a normal diet in average quantities of 1 g daily, their effects on the digestive system have only been recently investigated. This study used an in vitro model of colonic secretion, monolayers of T84 colonic adenocarcinoma cells mounted in Ussing chambers, to demonstrate that 100 mumol/L of either tangeritin or nobiletin, polymethoxylated flavonoids contained in citrus fruits, stimulated sustained electrogenic chloride secretion with a maximal short-circuit current of 3.3 microA/cm2. In contrast, naringin and hesperidin, glycosylated citrus flavonoids, stimulated minimal secretion, suggesting that carbohydrate substitutions inhibited their secretory potential. The secretion stimulated by tangeritin and nobiletin was synergistic with carbachol but not with vasoactive intestinal peptide and was inhibited by barium chloride, bumetanide, H-89, and Cl- depletion. These properties suggest that tangeritin and nobiletin stimulated Cl- secretion via the cAMP pathway; however, these flavonoids did not stimulate cAMP production to the extent seen with vasoactive intestinal peptide. These flavonoids did not autooxidize, suggesting that reactive oxygen species did not mediate this secretion. These observations suggest that dietary citrus flavonoids may modulate colonic secretion, possibly through direct interaction with intracellular secretory pathways.

Topics: Adenocarcinoma; Carbachol; Chlorides; Citrus; Colon; Colonic Neoplasms; Cyclic AMP; Cyclic GMP; Drug Synergism; Flavanones; Flavones; Flavonoids; Glycosylation; Humans; Kinetics; Tumor Cells, Cultured

Metastatic mouse mammary tumor cell line 4526 was used to determine whether linoleate (LN)-derived cyclooxygenase metabolites were involved in the mechanism of LN-enhanced 4526 tumor growth. Unstimulated line 4526 cells converted LN to both PGE1 and PGE2 in serum free medium (SFM). However, neither prostaglandin (PG) influenced growth, while db-cGMP, but not db-cAMP, stimulated growth to the same extent as LN. Cyclooxygenase inhibitors stimulated growth while suppressing PG synthesis. Lipoxygenase inhibitors decreased growth in a dose dependent manner. Supplemental LN had no effect on cyclooxygenase inhibition while the IC50s for lipoxygenase inhibition were increased several fold. These results indicate that lipoxygenase products rather than cyclooxygenase metabolites play a major role in LN-stimulated growth of line 4526 cells.

Topics: Adenocarcinoma; Animals; Cell Division; Cell Line; Cyclic AMP; Cyclic GMP; Eicosanoids; Female; Indomethacin; Linoleic Acids; Lipoxygenase Inhibitors; Mammary Neoplasms, Experimental; Mice; Prostaglandins

Topics: Adenocarcinoma; Colonic Neoplasms; Cyclic AMP; Cyclic GMP; Humans; Intestinal Obstruction

For providing some experimental basis in establishing malignant phenotypic reversed indexes of gastric carcinoma cells, human gastric adenocarcinoma cell line MGc-80-3 was induced by dBcAMP in vitro to appraise the effect of gastric carcinoma cell differentiation by chemical inducers. Under light microscope, MGc 80-3 cells, after treated with 1 mM dBcAMP, tended to be flat and disperse, and their volume gradually enlarged, with their nucleus relatively smaller and their shape rather regular. Morphological changes, became like normal differentiated epithelial cells, were observed. The cells attached firmly, grew slowly, their growth curve showed inhibitory rate amounted to 52.87%, and cellular division exponent displayed their peak value 1.5 times less than that of MGc 80-3 cells. It was clear that dBcAMP could effectively inhibit the multiplication activity of MGc-80-3 cells. In the cells after dBcAMP treatment, remarkable changes of cell surface charges was indicated by cell electrophoresis, the ratio dropped to 3.043 from 3.988, and their retardant ratio reached up to 31.2%. cAMP content in cells after this treatment, detected by cAMP and cGMP radioimmunoassay, was enhanced by 2.42 times; and cAMP/cGMP ratio, by 1.73 times. Thus, cAMP level within MGc 80-3 cells was raised obviously by dBcAMP. Heterotransplantation experiments showed that tumoriferous rate of MGc 80-3 cells (transplanted subcutaneously to BABL/c mice) amounted to 100%, and that of the cells after this treatment was only 5.6%. Their tumorigenic ability was extremely reduced. These results fully confirmed that dBcAMP was able to change MGc 80-3 cell's malignant phenotypic characteristics and produce a reversed alteration; thus, it has a remarkable inductive effect in differentiating gastric carcinoma cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adenocarcinoma; Animals; Bucladesine; Cell Differentiation; Cyclic AMP; Cyclic GMP; Humans; Male; Mice; Mice, Inbred BALB C; Neoplasm Transplantation; Stomach Neoplasms; Tumor Cells, Cultured

Association of neurotensin to its receptor in HT29 cells increases the intracellular concentration of inositol phosphates. A rapid (20-30 s), transient stimulation of inositol trisphosphate (275% of the basal level) and inositol bisphosphate (420%) is first observed, followed by a slower, stable increase in inositol monophosphate (170%). Half-maximal stimulation of the three inositol phosphates was obtained with 50-100 nM neurotensin. These results indicate that neurotensin is able to regulate intracellular Ca2+ levels in HT29 cells by using inositol trisphosphate as a second messenger.

Topics: Adenocarcinoma; Cell Line; Colonic Neoplasms; Cyclic AMP; Cyclic GMP; Humans; Inositol Phosphates; Kinetics; Neurotensin; Phosphatidylinositols; Receptors, Neurotensin; Receptors, Neurotransmitter; Tetradecanoylphorbol Acetate

Tissues from tumor and normal intestine were examined in 44 patients suffering from colonic and rectal cancer. The study established elevated levels of cholesterol (chiefly, cholesterol esters) and phospholipids, as compared with normal tissue. Two groups were identified among the cancer patients on the basis of the ratio of K = (Formula: see text). Cases with a relatively low value of K revealed higher levels of body fat and hyperlipidemia. That was matched by relatively higher concentrations of cholesterol and its esters, but not phospholipids, in tumor tissue, as compared with normal one. The relationship between cyclic nucleotide metabolism disorders in neoplastic tissue and lipid metabolism in cancer patients is discussed.

Topics: Adenocarcinoma; Cholesterol; Cholesterol Esters; Colonic Neoplasms; Cyclic AMP; Cyclic GMP; Humans; Middle Aged; Phospholipids; Rectal Neoplasms

Prostaglandin E2 and cyclic nucleotide levels were measured in plasma and urine of 14 patients with colonic cancer. The measurements were performed 1 day before and 8 days after the removal of the tumor by operation. There was no difference between the plasma PGE2 levels (in form of the 13, 14-dihydro-15-keto metabolite) before and after the operation, but they were significantly higher than the level of a control group. No differences before and after operation were found between plasma cyclic AMP (cAMP) levels, plasma cyclic GMP (cGMP) levels, urinary cAMP levels and urinary cGMP levels. All the cyclic nucleotide concentrations were within the normal range. No correlation could be found between the stage of the tumor spread and any of the substances analyzed. The conclusions are that plasma PGE2 and plasma and urinary cyclic nucleotides do not originate from the colonic tumor tissue, and that these substances cannot be used as tumor markers.

Topics: Adenocarcinoma; Adult; Aged; Colonic Neoplasms; Cyclic AMP; Cyclic GMP; Dinoprostone; Female; Humans; Male; Middle Aged; Prostaglandins E

This study deals with the growth effect of gastrin on two xenotransplantable human gastric carcinomas (SC-6-JCK, poorly differentiated adenocarcinoma; and St-15, mucinous adenocarcinoma) and on one colonic carcinoma (Co-3, well-differentiated adenocarcinoma). In SC-6-JCK, the treatment with s.c. injection of pentagastrin at a dose of 10 micrograms/mouse once daily for 25 days promoted the growth of the tumor transplanted in nude mice, but gastrin had no effect at all on St-15 and Co-3. In SC-6-JCK, the weight, size, and labeling index of [3H]thymidine of the tumor were significantly increased in comparison with those of the control (p less than 0.05). In SC-6-JCK, cyclic adenosine 3':5'-monophosphate (cAMP) in the tumor was increased by a single i.p. injection of pentagastrin at a dose of 20 micrograms/mouse in nude mice, but such an increase was not observed in St-15 and Co-3. Cyclic guanosine 3':5'-monophosphate in SC-6-JCK was slightly increased by gastrin treatment but was not affected in the other tumors. In SC-6-JCK, at 30 min after gastrin treatment when cAMP showed a maximum increase, the activity ratio of cAMP-dependent protein kinase in the tumor was also elevated. In vitro also, gastrin stimulated cAMP production and cAMP-dependent protein kinase activation. The data suggest that some human gastric carcinomas may have receptor for gastrin.

Topics: Adenocarcinoma; Adult; Animals; Cell Division; Cell Line; Colonic Neoplasms; Cyclic AMP; Cyclic GMP; Female; Gastrins; Humans; Kinetics; Male; Mice; Mice, Nude; Middle Aged; Neoplasm Transplantation; Protein Kinases; Stomach Neoplasms; Transplantation, Heterologous

The addition of molybdate to intact or homogenized cells of the endometrial adenocarcinoma line HEC-1 during incubation with [3H]estradiol ([3H]E2) at 4 C causes substantial increases in cytoplasmic E2 binding levels. A similar effect can be observed in homogenates of normal human endometrium. These effects of molybdate appear to involve activation of E2-binding sites. Fractionation of the homogenates and recombination of different fractions revealed that activation of specific E2-binding sites by by MoO4= requires cytosolic factors as well as factors associated with the cell membrane. In homogenates of neoplastic cells (HEC-1) and normal endometrium, the addition of ATP, GTP, or cGMP was also found to increase E2 binding to levels as high as those obtained by the addition of MoO4=. In contrast, the addition of cAMP was found to lower specific E2 binding levels and to counteract the effects of MoO4=, ATP, GTP, and cGMP. Levels of intracellular cAMP and cGMP can change rapidly in cells in culture. Since cGMP causes E2 binding levels to increase while cAMP causes them to decrease, changes in the levels of these two cyclic nucleotides may explain the fluctuation in concentrations of specific estrogen binders that we have previously reported to occur in cultured endometrial cells.

Topics: Adenocarcinoma; Adenosine Triphosphate; Cell Line; Cell Membrane; Cyclic AMP; Cyclic GMP; Cytosol; Endometrium; Estradiol; Female; Guanosine Triphosphate; Humans; Molybdenum; Uterine Neoplasms

Previous studies have shown that various amine hormones are able to influence the growth rate of human colorectal carcinomas propagated as xenografts in immune-deprived mice, and it is now well known that the effects of many amine and other hormones are mediated by cyclic nucleotides, acting as second messengers within cells. In the present study the influence of various derivatives of cyclic adenosine monophosphate and cyclic guanosine monophosphate on the growth of two different lines of colorectal cancer growing in immune-deprived mice, and on the cell production rate in the colonic crypt epithelium of the rat, was assessed. Growth of each tumour line, as well as crypt-cell production, was suppressed by treatment wit N6O2' dibutyryl and N6 monobutyryl derivatives of cyclic adenosine monophosphate. Dibutyryl cyclic guanosine monophosphate, on the other hand, was found to promote the growth of Tumour HXK4 and to promote crypt cell production, but to have no significant effect on Tumour HXM2.

Topics: Adenocarcinoma; Animals; Cell Division; Colon; Colonic Neoplasms; Cyclic AMP; Cyclic GMP; Epithelium; Female; Male; Mice; Neoplasm Transplantation; Neoplasms, Experimental; Rats; Transplantation, Heterologous

Topics: 3',5'-Cyclic-AMP Phosphodiesterases; 3',5'-Cyclic-GMP Phosphodiesterases; Adenocarcinoma; Animals; Ceruletide; Cyclic AMP; Cyclic GMP; Dose-Response Relationship, Drug; Humans; Mice; Pancreatic Neoplasms; Receptors, Cell Surface; Receptors, Cholecystokinin; Receptors, G-Protein-Coupled; Receptors, Gastrointestinal Hormone; Secretin; Theophylline

Weanling F344 rats, which were fed a diet containing 10% chrysotile (B), were studied over their life-time to determine the effects of ingested asbestos on the colon. Control groups consisted of rats fed a diet containing a 10% nonnutritive cellulose or a standard laboratory rat diet. The pathological findings in the colons of 501 rats (189 on asbestos diet, 197 on fiber control diet, and 115 on standard control diet), are reported here. Epithelial tumors of the colon (eight adenocarcinomas and one adenoma) were found in nine of the rats on study. Four of the tumors were in asbestos-fed rats, two tumors were found in the non-nutritive cellulose controls, and three tumors were found in the standard laboratory rat diet controls. The probability (based on actuarial analysis) of developing adenoma or adenocarcinomas during the 32 months of the study were 7.4% for the asbestos-fed group, 3.5% for the fiber control diet and 4.0% on the standard control diet. In addition, one malignant mesothelioma of the type induced by intraperitoneally administered asbestos was found in the asbestos-fed group. Non-neoplastic lesions of the colon were also evaluated. The cumulative risk for development of any colon-associated lesion (non-neoplastic plus neoplastic lesions) was greatest for asbestos-fed rats (17.9%), compared to 13.6% for those fed the fiber control diet and 8.2% for those fed the standard control diet. The colon tissue levels of adenosine, 3'-5'-cyclic monophosphate (cAMP) were significantly lower in the animals fed asbestos compared to the control diets. Chrysotile fibers were seen by electronmicroscopy (e.m.) in six of ten ashed colon specimens of rats fed the asbestos diet. Although the differences in numbers of tumors between the animals fed asbestos and the controls were not statistically significant at the 5% level, we felt that the combination of observations including 1) evidence of increased probability of asbestos-fed animals to develop colon lesions in general; 2) evidence of a special type of mesothelioma in rats fed asbestos; 3) evidence for a cell regulator defect (lowered cAMP levels) in colon tissues of animals fed asbestos; and 4) evidence for asbestos fiber penetration of the colonic mucosa (e.m. studies) suggest that ingested asbestos is not inert in the colon.

Topics: Adenocarcinoma; Adenoma; Animals; Asbestos; Colon; Colonic Neoplasms; Cyclic AMP; Cyclic GMP; Dietary Fiber; Female; Male; Mesothelioma; Neoplasms, Experimental; Rats; Rats, Inbred F344; Time Factors

The adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3',5'-cyclic monophosphate (cGMP) levels were determined in the small and large intestinal tissue of rats that had been exposed to single and chronic administration of the colon carcinogen 1,2-dimethylhydrazine (DMH). A single subcutaneous injection of DMH resulted in a decrease in the intracellular concentration of cAMP and increase in cGMP beyond the levels which had been measured in the unexposed intestinal tissue and DMH induced intestinal adenocarcinomas. Recovery to normal concentrations of the cyclic nucleotides occurred within 30 days. Multiple exposures resulted in maintaining reduced levels of cAMP while cGMP was also found to be lowered upon the chronic administration. A possible explanation for these observations is the expansion of the crypt cell population consisting of replicating intestinal cells that occurs upon exposure to the carcinogen. These findings suggest that cyclic nucleotide alterations may represent a characteristic of the precancerous state of intestinal tissue and indicates further studies are warranted to determine whether these changes may serve as a useful marker in a screening program for colon cancer.

Topics: Adenocarcinoma; Animals; Colonic Neoplasms; Cyclic AMP; Cyclic GMP; Dimethylhydrazines; Injections, Subcutaneous; Intestinal Neoplasms; Kinetics; Male; Precancerous Conditions; Rats

We have recently described the presence of a guanylate cyclase [GTP pyrophosphate-lyase (cyclizing), EC 4.6.1.2] inhibitor (GCI) in an aqueous extract of the balsam pear (Momordica charantia abbreviata). Because the guanylate cyclase-cyclic GMP system is though to be involved in cell growth, DNA and RNA synthesis, and possible malignant transformation, we examined the effect of the aqueous extract containing GCI on an undifferentiated adenocarcinoma of the rat prostate and concanavalin-A-stimulated [3H]thymidine incorporation into cultured splenic lymphocytes, a process thought to be mediated by cyclic GMP. The results demonstrate that the extract of the balsam pear blocks both the growth of the rat prostatic adencarcinoma in vitro and [3H]thymidine incorporation into DNA. DNA histograms from flow cytometry indicated that the extract containing GCI inhibited in the G2 + M phase of the cell cycle, a presumed locus of cyclic GMP effects. In addition, guanylate cyclase activity was significantly greater in the tumor than normal prostate tissue and was decreased by the extract containing GCI. Cyclic GMP levels in the tumor in culture wer also decreased by addition of the extract. It remains to be determined whether or not the anti-tumor agent and GCI are the same substance.

Topics: Adenocarcinoma; Animals; Cell Cycle; Concanavalin A; Cyclic GMP; Guanylate Cyclase; In Vitro Techniques; Male; Neoplasms, Experimental; Plant Extracts; Prostatic Neoplasms; Thymidine

The intracellular concentrations of adenosine 3',5'-cyclic monophosphate (cAMP) in colonic tumors induced in adult male Holtzman rats by 1,2-dimethylhydrazine (DMH) were found to be 1/2 the concentration found in normal large bowel tissue. Intracellular concentrations of guanosine 3'-5'-cyclic monophosphate (cGMP) in the neoplastic cells were twice the normal colon level. The concentrations of these two cyclic nucleotides were relatively constant throughout the normal colon. Thus, the anomalous tumor cyclic nucleotide concentrations are attributed to the specific cell population of the lesion and not to the site of development within the colon.

Topics: Adenocarcinoma; Animals; Colonic Neoplasms; Cyclic AMP; Cyclic GMP; Dimethylhydrazines; Female; Rats

The intracellular concentrations of adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3',5'-cyclic monophosphate (cGMP) were determined in adult male Holtzman rat small intestinal tumors induced by subcutaneous administration of 1,2-dimethylhydrazine (DMH) or X-irradiation of only the hypoxic ileum and jejunum. The levels of cAMP and cGMP in the cancer cells from DMH-treated animals were 50% and 200%, respectively, of the values measured for intestinal tissue. The amounts of cGMP in the lesion of the X-irradiation induced rat small bowel adenocarcinoma determined in the present investigation and of cAMP measured previously were observed to be only 50% of the value for unirradiated intestine. It has thus been shown that in the DMH-induced colon and small intestinal tumors, the X-irradiation induced rat small bowel adenocarcinoma and the human colon adenocarcinoma, the cAMP concentrations are consistently about 50% of the levels measured in comparable normal tissues. These findings of diminished intracellular cAMP concentrations imply a serious cellular defect mechanism occurring in intestinal cancer. However, there appears to be no similar pattern of change for the intracellular concentrations of cGMP, which suggests that different biochemical pathways exist in these malignancies.

Topics: Adenocarcinoma; Animals; Cyclic AMP; Cyclic GMP; Dimethylhydrazines; Intestinal Neoplasms; Intestine, Small; Male; Neoplasms, Experimental; Neoplasms, Radiation-Induced; Rats

Topics: Adenocarcinoma; Adenylyl Cyclases; Animals; Biological Transport; Cell Membrane Permeability; Cyclic AMP; Cyclic GMP; Dogs; Kidney; Kidney Glomerulus; Kidney Medulla; Kidney Neoplasms; Kidney Tubules, Collecting; Kidney Tubules, Distal; Kidney Tubules, Proximal; Loop of Henle; Nephrectomy; Parathyroid Hormone; Prostaglandins; Rabbits; Rats; Vasopressins

Data from cultured cells have suggested that cyclic AMP and cyclic GMP may be important determinants of cell growth and transformation. However, few studies have examined cyclic nucleotide content and metabolism in naturally occurring tumors of man. Accordingly, in the present study we compared cAMP and cGMP levels and metabolism in carcinomas of the human colon to those of the adjacent uninvolved mucosa after therapeutic resection of these tissues. The cAMP content of the tumors, determined in samples frozen 30 min after excision, was significantly lower than that of the adjacent mucosa, when expressed on the basis of tissue wet weight, protein, or DNA content. By contrast, the cGMP content of the tumors was higher than that of the surrounding mucosa if calculated on the basis of tissue wet weight, but this difference did not persist when correction was made for the higher protein or DNA content of the tumors. Incubation of slices of mucosa or tumor with or without theophylline in vitro increased tissue cAMP and cGMP content above levels observed in frozen samples of the same tissue. However, after such incubations cAMP levels in the tumors remained clearly below that of the mucosa, while cGMP content of the two tissues did not differ. The failure of theophylline to abolish differences in cAMP content and the comparable activities of high and low Km cAMP-phosphodiesterase in homogenates of the two tissues suggested that the lower cAMP content of the tumors was a consequence of diminished cAMP synthesis rather than enhanced degradation. This possibility was supported by the reduction in basal and maximal prostaglandin E1 (PGE1)-responsive adenylate cyclase activity found in tumor homogenates relative to those of mucosa, and the lower levels of cAMP in tumor slices after incubation of the tissues with a maximal dose of PGE1 and theophylline. Since NaF-responsive adenylate cyclase activity was not significantly reduced in the tumors, the lower basal and PGE1 activities may not be related to a deficiency of the catalytic unit of the cyclase complex in this tissue. The role of reduced activity of the adenylate cyclase-cAMP system and/or reduced tissue cAMP-to-cGMP ratios in the pathogenesis of colonic carcinoma is uncertain, but these changes might favor unregulated cellular proliferation.

Topics: Adenocarcinoma; Adenylyl Cyclases; Colonic Neoplasms; Cyclic AMP; Cyclic GMP; DNA, Neoplasm; Humans; Intestinal Mucosa; Prostaglandins E; Theophylline