Effect of acylated derivatives of ascorbate on ornithine decarboxylase induction in Ehrlich ascites tumor cells.
We studied the effects of 6-0-acylated derivatives of ascorbate on ornithine decarboxylase (ODC, E.C.4.1.1.17) activity and the ODC-mRNA level in Ehrlich ascites cells. These derivatives are known to inhibit cell growth. When cells grown to the stationary phase were diluted and stimulated with fresh medium containing 10% dialyzed fetal calf serum, the ODC activity increased rapidly and transiently with a peak at 4 hr. Ascorbate or 2,6-dipalmitoyl ascorbate had little or no effect on the induction of ODC, but 6-0-palmitoyl ascorbate (6P) suppressed the enzyme activity in a time- and dose-dependent way. 6-0-Stearoyl ascorbate had a similar effect. The amount of ODC-mRNA formed after growth stimulation was not affected by 6P. These results indicate that the treatment of Ehrlich ascites tumor cells with 6P caused dose-dependent suppression of ODC induction post-transcriptionally.
Department of Biochemistry, Radioisotope Centre, Tokyo, Japan.
I
I
Matsui-Yuasa
S
S
Otani
S
S
Morisawa
K
K
Kageyama
Y
Y
Onoyama
H
H
Yamazaki
N
N
Miwa
D000107:Acetylation; D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology*; D002286:Carcinoma, Ehrlich Tumor / Q000201:enzymology* / Q000235:genetics; D004790:Enzyme Induction / Q000187:drug effects; D005260:Female; D051379:Mice; D008813:Mice, Inbred ICR; D009955:Ornithine Decarboxylase / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000187:drug effects
D012333:RNA, Messenger; D009955:Ornithine Decarboxylase; D001205:Ascorbic Acid