Addition of Zn2+_ to cell medium inhibited the induction of ornithine decarboxylase (ODC) activity in ODC overproducing L1210-DFMOr cells. A significant effect was observed at a concentration as low as 0.01 mM, however a more marked inhibition was caused by the addition of 0.1 mM Zn2+. The inhibition of the induction of ODC activity was accompanied by a proportional decrease in the content of immunoreactive ODC protein, whereas the level of ODC mRNA, detemined by a solution hybridization RNase protection assay, was not affected signigicantly. Instead, some acceleration of ODC turnover was observed. the addition of 0.1 mM Co2+ or Mn2+, but not of other divalent metal ions, also inhibited ODC induction; differently from Zn2+ however, these metals affected cell viability and/or cell growth. Removal of endogenous Zn2+ by a chelator also provoked a strong decrease of ODC induction, which was reversed by Zn2+. However, addition of Zn2+ in excess of the chelator proved to be markedly inhibitory. These results indicate that both a restricted Zn2+ availability and an enhanced presence of the metal can inhibit the induction of ODC in L1210-DFMOr cells. © 1994.
Flamigni F., Campana G., Carboni L., Rossoni C., Spampinato S. (1994). Post-transcriptional inhibition of ornithine decarboxylase induction by zinc in a difluoromethylornithine resistant cell line. BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS, 1201(1), 101-105 [10.1016/0304-4165(94)90157-0].
Post-transcriptional inhibition of ornithine decarboxylase induction by zinc in a difluoromethylornithine resistant cell line
Flamigni F.;Campana G.;Carboni L.;Rossoni C.;Spampinato S.
1994
Abstract
Addition of Zn2+_ to cell medium inhibited the induction of ornithine decarboxylase (ODC) activity in ODC overproducing L1210-DFMOr cells. A significant effect was observed at a concentration as low as 0.01 mM, however a more marked inhibition was caused by the addition of 0.1 mM Zn2+. The inhibition of the induction of ODC activity was accompanied by a proportional decrease in the content of immunoreactive ODC protein, whereas the level of ODC mRNA, detemined by a solution hybridization RNase protection assay, was not affected signigicantly. Instead, some acceleration of ODC turnover was observed. the addition of 0.1 mM Co2+ or Mn2+, but not of other divalent metal ions, also inhibited ODC induction; differently from Zn2+ however, these metals affected cell viability and/or cell growth. Removal of endogenous Zn2+ by a chelator also provoked a strong decrease of ODC induction, which was reversed by Zn2+. However, addition of Zn2+ in excess of the chelator proved to be markedly inhibitory. These results indicate that both a restricted Zn2+ availability and an enhanced presence of the metal can inhibit the induction of ODC in L1210-DFMOr cells. © 1994.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
