Selective synthesis and retention of 66k protein in a human neuroblastoma cell line (NCG) treated with a cytotoxic dosage of delta 12-prostaglandin J2.
delta 12-prostaglandin(PG)J2 (7.5 micrograms/ml) significantly inhibited protein synthesis and cell growth in a human neuroblastoma cell line (NCG), decreasing these factors by 31.5% and 78.2% of the control values, respectively. Two protein synthesis inhibitors, cycloheximide (CHM) and emetine, exhibited a dose-dependent protective effect for neuroblastoma cells against delta 12-PGJ2 cytotoxicity. At a concentration of 15 micrograms/ml CHM, the number of viable cells increased from 21.8% to 36.7% of the control value (p less than 0.01). The sodium dodecyl sulfate-polyacrylamide gel analysis of [35S]methionine-incorporated proteins revealed an increased synthesis of 86k, 70k and 66k proteins in the delta 12-PGJ2-treated NCG cells under the condition that delta 12-PGJ2 exerts cytotoxicity. Of these proteins, the amount of 66k protein was particularly increased in cell cytosol; however, its synthesis did not occur when CHM prohibited the delta 12-PGJ2 cytotoxic effect. When emetine was used instead of CHM, similar results were obtained. These results strongly suggest that the 66k protein plays a critical role in the delta 12-PGJ2 cytotoxicity.
Shimizu
Y
Y
Department of Pediatrics, Kyoto Prefectural University of Medicine, Kamikyoku, Japan.
Todo
S
S
Imashuku
S
S
D002455:Cell Division; D002460:Cell Line; D003513:Cycloheximide / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004640:Emetine / Q000494:pharmacology; D006801:Humans; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D009447:Neuroblastoma / Q000378:metabolism*; D015230:Prostaglandin D2 / Q000031:analogs & derivatives*; D011457:Prostaglandins D / Q000494:pharmacology*
D009363:Neoplasm Proteins; D011457:Prostaglandins D; C037112:9-deoxy-delta-9-prostaglandin D2; D003513:Cycloheximide; D015230:Prostaglandin D2; D004640:Emetine