cyclic-gmp and Carcinoma-256--Walker

A prospective, randomized experimental research.. To demonstrate the role of cGMP (cyclic guanosine monophosphate)-cGKI (cGMP-dependent protein kinase I) pathway in dorsal root ganglia (DRG) in bone cancer pain.. Treating bone cancer pain continues to possess a major clinical challenge because the specific cellular and molecular mechanisms underlying bone cancer pain remain elusive. cGMP and cGMP-dependent protein kinases pathway in DRG plays important role in nerve injury-induced hyperexcitability of DRG neurons, as well as neuropathic pain, however, whether this pathway participates in bone cancer pain is unknown.. The rat model of bone cancer pain was produced by intramedullary injection of rat breast cancer cells (Walker 256) into right tibia. Thermal hyperalgesia and mechanical allodynia were measured before and after administration of inhibitor of cGMP-cGKs pathway (Rp-8-pCPT-cGMPS). Immunofluorescence and reverse transcription-polymerase chain reaction were used to reflect expression of cGKI in DRG neurons, whereas the concentration of cGMP in DRG was tested using enzyme-linked immunosorbent assay method. Whole-cell patch clamp was used to record the hyperexcitability of small neurons in DRG with or without cGKs inhibitor after tumor cell implantation (TCI).. TCI treatment significantly increased the concentration of cGMP in DRG and activity of cGKs in DRG and the spinal cord. TCI treatment also induced upregulation of cGKI messenger ribonucleic acid and protein in DRG, as well as enhanced hyperexcitability in DRG neurons. Spinal administration of Rp-8-pCPT-cGMPS, cGMP-cGKs inhibitor, significantly suppressed TCI-induced activation of cGMP-cGKI signaling, and hyperexcitability of DRG neurons. Meanwhile, in vivo intrathecal delivery of the Rp-8-pCPT-cGMPS significantly prevented and suppressed TCI-induced hyperalgesia and allodynia.. From these results, we confirm that TCI treatment activates cGMP-cGKI signaling pathway and continuing activation of this pathway in DRG is required for hyperalgesia and/or hyperalgesia and allodynia after TCI treatment.. N/A.

Topics: Animals; Bone Neoplasms; Carcinoma 256, Walker; Cyclic GMP; Cyclic GMP-Dependent Protein Kinase Type I; Enzyme Induction; Female; Ganglia, Spinal; Hot Temperature; Hyperalgesia; Neoplasm Proteins; Pain Threshold; Patch-Clamp Techniques; Protein Kinase Inhibitors; Random Allocation; Rats; Rats, Sprague-Dawley; RNA, Messenger; RNA, Neoplasm; Sensory Receptor Cells; Thionucleotides; Tibia; Touch

Implantation of Walker 256 tumor decreases acute systemic inflammation in rats. Inflammatory hyperalgesia is one of the most important events of acute inflammation. The L-arginine/NO/cGMP/K(+)ATP pathway has been proposed as the mechanism of peripheral antinociception mediated by several drugs and physical exercise. The objective of this study was to investigate a possible involvement of the NO/cGMP/K(+)ATP pathway in antinociception induced in Walker 256 tumor-bearing male Wistar rats (180-220 g). The groups consisted of 5-6 animals. Mechanical inflammatory hypernociception was evaluated using an electronic version of the von Frey test. Walker tumor (4th and 7th day post-implantation) reduced prostaglandin E(2)- (PGE(2), 400 ng/paw; 50 µL; intraplantar injection) and carrageenan-induced hypernociception (500 µg/paw; 100 µL; intraplantar injection). Walker tumor-induced analgesia was reversed (99.3% for carrageenan and 77.2% for PGE(2)) by a selective inhibitor of nitric oxide synthase (L-NAME; 90 mg/kg, ip) and L-arginine (200 mg/kg, ip), which prevented (80% for carrageenan and 65% for PGE(2)) the effect of L-NAME. Treatment with the soluble guanylyl cyclase inhibitor ODQ (100% for carrageenan and 95% for PGE(2); 8 µg/paw) and the ATP-sensitive K(+) channel (KATP) blocker glibenclamide (87.5% for carrageenan and 100% for PGE(2); 160 µg/paw) reversed the antinociceptive effect of tumor bearing in a statistically significant manner (P < 0.05). The present study confirmed an intrinsic peripheral antinociceptive effect of Walker tumor bearing in rats. This antinociceptive effect seemed to be mediated by activation of the NO/cGMP pathway followed by the opening of KATP channels.

Topics: Analgesics; Animals; Arginine; Carcinoma 256, Walker; Carrageenan; Cyclic GMP; Dinoprostone; Hyperalgesia; KATP Channels; Male; Nitric Oxide; Nociception; Oxadiazoles; Pain Measurement; Pain Threshold; Quinoxalines; Rats; Rats, Wistar; Signal Transduction

Like many freely moving cells, Walker 256 carcinosarcoma cells respond to chemotactic stimuli. Since cyclic nucleotides are involved in the chemotaxis of other cells, we have examined the action of several nucleosides and nucleotides as chemoattractants and as modulators of tumor cell movement. We have also studied the effect of chemoattractants and prostaglandins on intracellular cyclic nucleotide levels and the effect of prostaglandins as modulators of chemotaxis. Of the agents studied, only the cyclic nucleotides and prostaglandins were found to modulate cellular motility. Neither cyclic adenosine 3':5'-monophosphate (cAMP) nor cyclic guanosine 3':5'-monophosphate (cGMP) was a chemoattractant, but cGMP and N6,O2'-dibutyryl cyclic guanosine 3':5'-monophosphate at low concentrations (approximately 10(-10) M to 10(-8) M) enhanced chemotaxis by 80 +/- 15%, and both cAMP and N6,O2-dibutyryl cyclic adenosine 3':5'-monophosphate had an inhibitory effect at concentrations greater than 10(-6) M. Chemotaxis was suppressed by 21 to 100% in media depleted of Ca2+ and/or Mg2+, but in the presence of 10(-8) M cGMP, there was partial recovery of the chemotactic response. In response to chemotactic stimulation, there was a 28 to 60% rise in intracellular cAMP within 30 sec. This returned to basal levels within 2 min. Intracellular cGMP levels became elevated approximately 3- to 3.5-fold after this time. Incubation of cells with prostaglandins A1 and F2 alpha stimulated chemotaxis at lower concentrations (10(-7) and 10(-9) M, respectively) and resulted in elevation of cGMP, while incubation with prostaglandin E2 resulted in inhibition of chemotaxis and a rise in cAMP levels.

Topics: Animals; Bucladesine; Carcinoma 256, Walker; Cell Line; Chemotactic Factors; Chemotaxis; Chemotaxis, Leukocyte; Cyclic AMP; Cyclic GMP; Dibutyryl Cyclic GMP; Dinoprost; Dinoprostone; Female; Prostaglandins A; Prostaglandins E; Prostaglandins F; Rats

The hepatic cyclic nucleotide system and hepatic monooxygenase activity were examined in male rats following intramuscular or subcutaneous Walker 256 carcinosarcoma transplantation. Twelve days of continuous s.c. tumor growth significantly increased hepatic cyclic AMP levels, while levels of cyclic GMP, cytochrome P-450, cytochrome b-5, and p-chloro-N-methylaniline metabolism were significantly decreased. Whole blood from 6 day i.m. tumor-bearing rats incubated with liver slices obtained from non-tumor-bearing rats produced significantly elevated hepatic cyclic AMP levels concurrent with significantly depressed hepatic p-chloro-N-methylaniline metabolism. The chronological monitoring of tumor growth demonstrated a close temporal relationship between decreased cyclic AMP-dependent protein kinase activity, microsomal metabolism of p-chloro-N-methylaniline, and the mixed-function oxidase system. Significant changes in these hepatic enzyme systems occurred as early as 17 hours following tumor transplantation. At this same time, sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed the appearance of a 184,000 molecular weight protein in hepatic tissue from all tumor-bearing rats. These studies are compatible with the proposal that the hepatic cyclic AMP system may modulate toxohormone effects on hepatic drug biotransformation.

Topics: Animals; Carcinoma 256, Walker; Cyclic AMP; Cyclic GMP; Liver; Male; Mixed Function Oxygenases; Neoplasm Transplantation; Rats; Transplantation, Homologous

The intracellular level of guanosine 3',5'-monophosphate (cGMP) has been measured in Walker carcinoma cells in tissue culture after treatment with various alkylating agents. At concentrations which caused a rise in the level of adenosine 3',5'-monophosphate (cAMP) chlorambucil and 5-(1-aziridinyl)-2,4-dinitrobenzamide (CB 1954) produced only a small (35%) elevation of cGMP, while merophan had no such effect. This suggests that any effect of cAMP will not be outweighed by an equivalent rise in cGMP. Sepcific cytosolic binding of cGMP decreased with increasing resistance of Walker cells to alkylating agents, while the dissociation constant, KD, for binding increased. This was also observed with cAMP binding which suggests that the same protein in responsible for binding both nucleotides.

Topics: Alkylating Agents; Animals; Aziridines; Azirines; Carcinoma 256, Walker; Cells, Cultured; Chlorambucil; Cyclic AMP; Cyclic GMP; Cytosol; Drug Resistance; Kinetics; Neoplasm Proteins; Protein Binding

Topics: Adenosine Triphosphate; Animals; Calcium; Carcinoma 256, Walker; Cattle; Cell Fractionation; Cell Nucleus; Chromatography, DEAE-Cellulose; Chromatography, Ion Exchange; Cyclic AMP; Cyclic GMP; Drug Stability; Histones; Hydrogen-Ion Concentration; Magnesium; Manganese; Organophosphorus Compounds; Phosphorus Radioisotopes; Protein Kinase Inhibitors; Protein Kinases; Rats; Structure-Activity Relationship; Thymus Gland