prostaglandin-a2 and Neuroblastoma

Effects of cyclopentenone prostaglandins, delta 12-prostaglandin (PG) J2 and PGA2 on the expression of N-myc in relation to the effects on cell cycle progression were investigated using human neuroblastoma cell line GOTO. Both PGs suppressed N-myc expression within several hours prior to inducing G1 arrest. The N-myc suppression with delta 12-PGJ2 was continued but with PGA2 it was gradually released, followed by the release of G1 arrest. These results suggest that delta 12-PGJ2 and PGA2 inhibit cell cycle progression in strong association with N-myc suppression and delta 12-PGJ2 is more potent and has a longer effect than PGA2.

Topics: Cell Cycle; Gene Expression Regulation; Genes, myc; Humans; Neuroblastoma; Prostaglandin D2; Prostaglandins A; Prostaglandins, Synthetic; Proto-Oncogene Proteins c-myc; RNA, Messenger; Suppression, Genetic; Tumor Cells, Cultured

The role of adenosine 3',5'-cyclic monophosphate (cAMP) and sodium butyrate in modifying the effect of heat on murine neuroblastoma cells (NBP2) in culture was evaluated on the criterion of survival. An elevation of cellular cAMP level by prostaglandin (PG) A2, a stimulator of adenylate cyclase, and 4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone (R020-1724), an inhibitor of cyclic nucleotide phosphodiesterase, only during heat treatment (43 degrees C and 40 degrees C) was sufficient to enhance the effect of heat. The extent of enhancement (additive versus synergistic) depended upon the cAMP stimulating agent and the experimental condition. When these agents were added after heat treatment for the entire observation period, they produced similar results. PGA2 and R020-1724 are known to increase the intracellular level of cAMP in these cells by three and fivefold, respectively; therefore, the effect of these agents in enhancing the heat-response may be mediated by cAMP-dependent mechanisms. The presence of sodium butyrate during heat treatment alone was ineffective; however, when it was added before or after heat treatment for the entire observation period, the survival of heated cell was markedly reduced.

Topics: 4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone; Animals; Butyrates; Butyric Acid; Cell Line; Cell Survival; Cyclic AMP; Hyperthermia, Induced; Mice; Neuroblastoma; Prostaglandins A

The effect of dl-alpha-tocopheryl (vitamin E) succinate in combination with Prostaglandin A2 (PGA2) and sodium butyrate on mouse neuroblastoma cells (NBP2) in culture, according to the criteria of growth inhibition and morphological differentiation (neurite formation), was studied. Results showed that PGA2 and sodium butyrate inhibited the growth of NB cells in a dose-dependent manner. The combined effects of vitamin E succinate with PGA2 or sodium butyrate, according to the criterion of growth inhibition, were additive. Vitamin E succinate by itself did not induce morphological differentiation, but it enhanced PGA2-induced morphological differentiation. Sodium butyrate alone or in combination with vitamin E succinate did not significantly increase the level of morphological differentiation. Sodium succinate and an equal amount of solvent (ethanol) failed to modify the effect of PGA2 or sodium butyrate. This suggests that the effect of vitamin E succinate in modifying the response of PGA2 and sodium butyrate on NB cells is due to the effect of vitamin E rather than to that of succinate.

Topics: Animals; Butyrates; Butyric Acid; Cells, Cultured; Cyclic AMP; Drug Synergism; Mice; Neuroblastoma; Prostaglandins A; Stimulation, Chemical; Tocopherols; Vitamin E

The effect of heat in combination with DL-alpha-tocopheryl (vitamin E) succinate and adenosine 3', 5'-cyclic monophosphate (cAMP) stimulating agents on mouse neuroblastoma cells ( NBP2 ) in culture on the criterion of growth inhibition (due to cell death and inhibition of cell division) was studied. Heat (41 degrees-40 degrees) alone inhibited growth; however, the extent of growth inhibition was dependent upon the temperature and the time of heat treatment. Heat (41 degrees-40 degrees) in combination with vitamin E succinate (5 micrograms/ml) produced an additive effect on the criterion of growth inhibition. Vitamin C (100 micrograms/ml) failed to modify the effect of heat. Prostaglandin A2, a stimulator of adenylate cyclase, and 4 - (3-butoxy-4-methoxybenzyl)-2-imidazolidinone ( R020 -1724), an inhibitor of cyclic nucleotide phosphodiesterase, are known to induce irreversible differentiation in mouse neuroblastoma cells in culture. These agents, in combination with heat (40 degrees) produced a synergistic effect on the criterion of growth inhibition. These data suggest that the addition of vitamin E and cAMP stimulating agents may increase the effectiveness of hyperthermia protocol.

Topics: 4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone; Animals; Cell Division; Cell Line; Cell Survival; Cyclic AMP; Hot Temperature; Imidazoles; Kinetics; Mice; Neuroblastoma; Prostaglandins A; Tocopherols; Vitamin E