title: HeLa cell RNA and protein syntheses. Effects of long-term treatment with 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB).
abstract: The population growth rate of HeLa cells treated with 60 microM 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) in reinforced Eagle's minimum essential medium was directly related to the concentration of fetal bovine serum in the range from 5 to 30%. Control cells proliferated at a maximal rate (doubling time: 18-19 hr) at serum concentrations in this range. In 60 microM DRB-containing medium supplemented with 5% serum, the inhibition of hnRNA synthesis after 1,5, and 48 hr of treatment was equivalent to 78, 84, and 51%, respectively, whereas that of protein synthesis was equivalent to 5, 41, and 49%. In 15% serum, the inhibition of hnRNA synthesis after 1, 5, and 48 hr of treatment was equivalent to 75, 79, and 40%, whereas that of protein synthesis was equivalent to 13, 30, and 21%. Thus, after 48 hr of treatment of cells with DRB in either 5 or 15% serum, hnRNA synthesis was less inhibited than it was after 1 or 5 hr of treatment, and the level of protein synthesis in DRB-treated cells did not decrease between the 5th and 48th hr. After 48 hr of treatment of cells with DRB in 15% serum, hnRNA and protein syntheses were both somewhat less inhibited than after treatment in 5% serum. These results suggest that, on prolonged treatment, HeLa cells undergo a partial, serum-dependent adaptation to the inhibitor.
mesh_terms: D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003470:Culture Media; D003609:Dactinomycin / Q000494:pharmacology; D003956:Dialysis; D004004:Dichlororibofuranosylbenzimidazole / Q000494:pharmacology*; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D007930:Leucine / Q000378:metabolism; D014176:Protein Biosynthesis; D012313:RNA / Q000096:biosynthesis*; D012263:Ribonucleosides / Q000494:pharmacology*; D014529:Uridine / Q000378:metabolism
chemical_list: D003470:Culture Media; D012263:Ribonucleosides; D003609:Dactinomycin; D004004:Dichlororibofuranosylbenzimidazole; D012313:RNA; D007930:Leucine; D014529:Uridine